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Viewing July 2000 — 39 paper(s) from the local store. (Local view only — run without --view to fetch new papers.)
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Also flagged:degradationabietane diterpenoidsabietane diterpenoidferredoxindioxygenaseabietanes
Journal Article 2000-07-01 No Snippets Martin VJ, Mohn WW.
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We have cloned and sequenced the dit gene cluster encoding enzymes of the catabolic pathway for abietane diterpenoid degradation by Pseudomonas abietaniphila BKME-9. The dit gene cluster is located on a 16.7-kb DNA fragment containing 13 complete open reading frames (ORFs) and 1 partial ORF. The genes ditA1A2A3 encode the alpha and beta subunits and the ferredoxin of the dioxygenase which hydroxylates 7-oxodehydroabietic acid to 7-oxo-11,12-dihydroxy-8, 13-abietadien acid. The dioxygenase mutant strain BKME-941 (ditA1::Tn5) did not grow on nonaromatic abietanes, and transformed palustric and abietic acids to 7-oxodehydroabietic acid in cell suspension assays. Thus, nonaromatic abietanes are aromatized prior to further degradation. Catechol 2,3-dioxygenase activity of xylE transcriptional fusion strains showed induction of ditA1 and ditA3 by abietic, dehydroabietic, and 7-oxodehydroabietic acids, which support the growth of strain BKME-9, as well as by isopimaric and 12, 14-dichlorodehydroabietic acids, which are diterpenoids that do not support the growth of strain BKME-9. In addition to the aromatic-ring-hydroxylating dioxygenase genes, the dit cluster includes ditC, encoding an extradiol ring cleavage dioxygenase, and ditR, encoding an IclR-type transcriptional regulator. Although ditR is not strictly required for the growth of strain BKME-9 on abietanes, a ditR::Km(r) mutation in a ditA3::xylE reporter strain demonstrated that it encodes an inducer-dependent transcriptional activator of ditA3. An ORF with sequence similarity to genes encoding permeases (ditE) is linked with genes involved in abietane degradation.

Also flagged:Hsp70hsp40chaperonespolyglutamineneurodegenerative diseasesheat shock protein
Journal Article 2000-07-01 ✓ 5 Snippets Muchowski PJ, Schaffar G, Sittler A, Wanker EE, Hayer-Hartl MK, Hartl FU.
In-Text Gene Mentions

Hsp40 suppressed the assembly of htt into detergent-insoluble amyloid

…fragments of huntingtin (htt) with expanded polyQ…

…the assembly ofhttinto detergent-insoluble amylo…

…or Hsp40 withhttin yeast inhibited…

htt

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The deposition of protein aggregates in neurons is a hallmark of neurodegenerative diseases caused by polyglutamine (polyQ) proteins. We analyzed the effects of the heat shock protein (Hsp) 70 chaperone system on the aggregation of fragments of huntingtin (htt) with expanded polyQ tracts. In vitro, Hsp70 and its cochaperone Hsp40 suppressed the assembly of htt into detergent-insoluble amyloid-like fibrils in an ATP-dependent manner and caused the formation of amorphous, detergent-soluble aggregates. The chaperones were most active in preventing fibrillization when added during the lag phase of the polymerization reaction. Similarly, coexpression of Hsp70 or Hsp40 with htt in yeast inhibited the formation of large, detergent-insoluble polyQ aggregates, resulting in the accumulation of detergent-soluble inclusions. Thus, the recently established potency of Hsp70 and Hsp40 to repress polyQ-induced neurodegeneration may be based on the ability of these chaperones to shield toxic forms of polyQ proteins and to direct them into nontoxic aggregates.

Also flagged:Munc13-1Munc13-2Munc13-3synaptic vesicleexocytosissynapses
Journal Article 2000-07-01 No Snippets Koch H, Hofmann K, Brose N.
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Munc13 proteins constitute a family of three highly homologous molecules (Munc13-1, Munc13-2 and Munc13-3). With the exception of a ubiquitously expressed Munc13-2 splice variant, Munc13 proteins are brain-specific. Munc13-1 has a central priming function in synaptic vesicle exocytosis from glutamatergic synapses. In order to identify Munc13-like proteins that may regulate secretory processes in non-glutamatergic neurons or non-neuronal cells, we developed protein profiles for two Munc13-homology-domains (MHDs). MHDs are present in a wide variety of proteins, some of which have previously been implicated in membrane trafficking reactions. Taking advantage of partial sequences in the human expressed sequence tag (EST) database, we characterized a novel, ubiquitously expressed, rat protein (Munc13-4) that belongs to a subfamily of Munc13-like molecules, in which the typical Munc13-like domain structure is conserved. Munc13-4 is predominantly expressed in lung where it is localized to goblet cells of the bronchial epithelium and to alveolar type II cells, both of which are cell types with secretory function. In the present study we identify a group of novel proteins, some of which may function in a Munc13-like manner to regulate membrane trafficking. The MHD profiles described in the present study are useful tools for the identification of Munc13-like proteins, that would otherwise have remained undetected.

Also flagged:p130phospholipase-CIns(1,4,5)P(3)-binding proteinphospholipase C-deltaphospholipaseinositol
Journal Article 2000-07-01 No Snippets Takeuchi H, Oike M, Paterson HF, Allen V, Kanematsu T, Ito Y, Erneux C, Katan M, Hirata M.
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p130 was originally identified as an Ins(1,4,5)P(3)-binding protein similar to phospholipase C-delta but lacking any phospholipase activity. In the present study we have further analysed the interactions of p130 with inositol compounds in vitro. To determine which of the potential ligands interacts with p130 in cells, we performed an analysis of the cellular localization of this protein, the isolation of a protein-ligand complex from cell lysates and studied the effects of p130 on Ins(1,4,5)P(3)-mediated Ca(2+) signalling by using permeabilized and transiently or stably transfected COS-1 cells (COS-1(p130)). In vitro, p130 bound Ins(1,4,5)P(3) with a higher affinity than that for phosphoinositides. When the protein was isolated from COS-1(p130) cells by immunoprecipitation, it was found to be associated with Ins(1,4,5)P(3). Localization studies demonstrated the presence of the full-length p130 in the cytoplasm of living cells, not at the plasma membrane. In cell-based assays, p130 had an inhibitory effect on Ca(2+) signalling. When fura-2-loaded COS-1(p130) cells were stimulated with bradykinin, epidermal growth factor or ATP, it was found that the agonist-induced increase in free Ca(2+) concentration, observed in control cells, was inhibited in COS-1(p130). This inhibition was not accompanied by the decreased production of Ins(1,4,5)P(3); the intact p130 pleckstrin homology domain, known to be the ligand-binding site in vitro, was required for this effect in cells. These results suggest that Ins(1,4,5)P(3) could be the main p130 ligand in cells and that this binding has the potential to inhibit Ins(1,4,5)P(3)-mediated Ca(2+) signalling.

Also flagged:hereditary hemochromatosisAlzheimer diseasemajor histocompatibility complexironfamilial Alzheimer diseaseDown syndrome
Journal Article 2000-07-01 ✓ 5 Snippets Moalem S, Percy ME, Andrews DF, Kruck TP, Wong S, Dalton AJ, Mehta P, Fedor B, Warren AC.
In-Text Gene Mentions

…complex gene calledHFEare associated with…

…factor for AD;HFEmutations were overrepresented…

…the distribution ofHFEmutations were apparent…

…E4 negative individualsHFEmutations are predisposing…

…in females lackingHFEmutations.…

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Mutations in the class I-like major histocompatibility complex gene called HFE are associated with hereditary hemochromatosis (HHC), a disorder of excessive iron uptake. We screened DNA samples from patients with familial Alzheimer disease (FAD) (n = 26), adults with Down syndrome (DS) (n = 50), and older (n = 41) and younger (n = 52) healthy normal individuals, for two HHC point mutations-C282Y and H63D. Because the apolipoprotein E (ApoE) E4 allele is a risk factor for AD and possibly also for dementia of the AD type in DS, DNA samples were also ApoE genotyped. Chi-squared analyses were interpreted at the 0.05 level of significance without Bonferroni corrections. In the pooled healthy normal individuals, C282Y was negatively associated with ApoE E4, an effect also apparent in individuals with DS but not with FAD. Relative to older normals, ApoE E4 was overrepresented in both males and females with FAD, consistent with ApoE E4 being a risk factor for AD; HFE mutations were overrepresented in males and underrepresented in females with FAD. Strong gender effects on the distribution of HFE mutations were apparent in comparisons among ApoE E4 negative individuals in the FAD and healthy normal groups (P < 0.002). Our findings are consistent with the proposition that among ApoE E4 negative individuals HFE mutations are predisposing to FAD in males but are somewhat protective in females. Further, ApoE E4 effects in our FAD group are strongest in females lacking HFE mutations. Relative to younger normals there was a tendency for ApoE E4 and H63D to be overrepresented in males and underrepresented in females with DS. The possibility that HFE mutations are important new genetic risk factors for AD should be pursued further.

Also flagged:preeclampsiafactor V Leidenmethylenetetrahydrofolate reductaseprothrombinprotein Cprotein S
Journal Article 2000-07-01 ✓ 1 Snippet Kupferminc MJ, Fait G, Many A, Gordon D, Eldor A, Lessing JB.
In-Text Gene Mentions

…protein S, andantithrombin-III; and for the…

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<h4>Objective</h4>To determine whether severe preeclampsia is associated with genetic thrombophilic mutations or other types of thrombophilia.<h4>Methods</h4>A case-control study compared 63 consecutive women with severe preeclampsia evaluated at our institution between November 1997 and April 1999 with 126 control women matched for age and ethnicity. All of these women were tested several months after delivery for mutations of factor V Leiden, methylenetetrahydrofolate reductase, and prothrombin gene; for deficiencies of protein C, protein S, and antithrombin-III; and for the presence of anticardiolipin antibodies.<h4>Results</h4>Thirty-five study women (56%) had a thrombophilic mutation compared with 24 control women (19%), P <.001. Seven other study women (11%) had other thrombophilias, compared with one control woman (0.8%), P <.01. Within the study group, women with thrombophilia delivered at an earlier gestational age, and their neonates' birth weights were lower compared with those of women without thrombophilia.<h4>Conclusion</h4>Because thrombophilia was found in 67% of women with severe preeclampsia, we suggest that women who have severe preeclampsia should be tested for thrombophilia.

Also flagged:Slit2axonsgrowth conemembranesgrowth conesaxon
Journal Article 2000-07-01 No Snippets Niclou SP, Jia L, Raper JA.
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We set out to isolate inhibitory guidance cues that affect retinal ganglion cell (RGC) axons in vitro and that could potentially be involved in RGC pathfinding decisions. Here we describe the biochemical purification of an RGC growth cone collapsing factor from bovine brain membranes and its identification as Slit2. Recombinant human Slit2 collapses and repels RGC growth cones from all quadrants of the chick retina. In the developing mouse visual system, slit2 is expressed in the eye, in the optic stalk, and in the ventral diencephalon. Slit2 expression is strong in anterior ventral diencephalic structures but is absent from the ventral midline where the optic chiasm forms. The putative receptors for Slits, robo1 and robo2, are expressed in the inner retinal layer in which RGCs are located. A comparison of the expression patterns of Slit2 and retinal axon trajectories suggests that slit2 acts as a short range repellent for retinal ganglion cell axons.

Also flagged:serotonin transporterSERTserotoninpolyethyleniminenucleussleep
Journal Article 2000-07-01 ✓ 5 Snippets Fabre V, Boutrel B, Hanoun N, Lanfumey L, Fattaccini CM, Demeneix B, Adrien J, Hamon M, Martres MP.
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With the aim of exploring the relationship between the serotonin transporter (5-HTT or SERT) and the activity level of serotonin (5-HT) neurotransmission, in vivo expression of this protein was specifically altered using a nonviral DNA transfer method.

…the serotonin transporter (5-HTTor SERT) and…

…sequence of the5-HTTgene were complexed…

…Such changes in5-HTTexpression were associated…

…altered expression of5-HTTby recombinant plasmids…

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With the aim of exploring the relationship between the serotonin transporter (5-HTT or SERT) and the activity level of serotonin (5-HT) neurotransmission, in vivo expression of this protein was specifically altered using a nonviral DNA transfer method. Plasmids containing the entire coding sequence or a partial antisense sequence of the 5-HTT gene were complexed with the cationic polymer polyethylenimine and injected into the dorsal raphe nucleus of adult male rats. Significant increase or decrease in both [(3)H]citalopram binding and [(3)H]5-HT synaptosomal uptake were observed in various brain areas up to 2 weeks after a single administration of the sense plasmid or 7 d after injection of the short antisense plasmid, respectively. Such changes in 5-HTT expression were associated with functional alterations in 5-HT neurotransmission, as shown by the increased capacity of 5-HT(1A) receptor stimulation to enhance [(35)S]GTP-gamma-S binding onto the dorsal raphe nucleus in sections from rats injected with the sense plasmid. Conversely, both a decrease in 5-HT(1A)-mediated [(35)S]GTP-gamma-S binding and a reduced potency of the 5-HT(1A) receptor agonist ipsapirone to inhibit neuronal firing were observed in the dorsal raphe nucleus of antisense plasmid-injected rats. Furthermore, changes in brain 5-HT and/or 5-HIAA levels, and sleep wakefulness circadian rhythm in the latter animals demonstrated that altered expression of 5-HTT by recombinant plasmids has important functional consequences on central 5-HT neurotransmission in adult rats.

Also flagged:cognitionHuntington's diseaseHDneurodegenerativebrain disorderpolyglutamine
Journal Article 2000-07-01 No Snippets Murphy KP, Carter RJ, Lione LA, Mangiarini L, Mahal A, Bates GP, Dunnett SB, Morton AJ.
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Huntington's disease (HD) is an autosomal dominant progressive and fatal neurodegenerative brain disorder caused by an expanded CAG/polyglutamine repeat in the coding region of the gene. Presymptomatic Huntington's disease patients often exhibit cognitive deficits before the onset of classical symptoms. To investigate the possibility that changes in synaptic plasticity might underlie cognitive impairment in HD, we examined hippocampal synaptic plasticity and spatial cognition in a transgenic mouse (R6/2 line) expressing exon 1 of the human Huntington's disease gene containing an expanded CAG repeat. This mouse exhibits a progressive and fatal neurological phenotype that resembles Huntington's disease. We report that R6/2 mice show marked alterations in synaptic plasticity at both CA1 and dentate granule cell synapses, and impaired spatial cognitive performance in the Morris water maze. The changes in hippocampal plasticity were age dependent, appearing at CA1 synapses several weeks before they were observed in the dentate gyrus. Deficits in synaptic plasticity at CA1 synapses occurred before an overt phenotype. This suggests that altered synaptic plasticity contributes to the pre-symptomatic changes in cognition reported in human carriers of the Huntington' disease gene. The temporal and regional changes in synaptic plasticity within the hippocampus mirror the appearance of neuronal intranuclear inclusions, suggesting a relationship between polyglutamine aggregation and dysfunction.

Also flagged:Huntington's diseaseHDneurodegenerative disordersubcortical dementiapolyglutaminecytoplasm
Journal Article 2000-07-01 No Snippets Turmaine M, Raza A, Mahal A, Mangiarini L, Bates GP, Davies SW.
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Huntington's disease (HD) is a fatal inherited neurodegenerative disorder characterized by personality changes, motor impairment, and subcortical dementia. HD is one of a number of diseases caused by expression of an expanded polyglutamine repeat. We have developed several lines of mice that are transgenic for exon 1 of the HD gene containing an expanded CAG sequence. These mice exhibit a defined neurological phenotype along with neuronal changes that are pathognomonic for the disease. We have previously observed the appearance of neuronal intranuclear inclusions, but did not find evidence for neurodegeneration. In this study, we report that all lines of these mice develop a late onset neurodegeneration within the anterior cingulate cortex, dorsal striatum, and of the Purkinje neurons of the cerebellum. Dying neurons characteristically exhibit neuronal intranuclear inclusions, condensation of both the cytoplasm and nucleus, and ruffling of the plasma membrane while maintaining ultrastructural preservation of cellular organelles. These cells do not develop blebbing of the nucleus or cytoplasm, apoptotic bodies, or fragmentation of DNA. Neuronal death occurs over a period of weeks not hours. We also find degenerating cells of similar appearance within these same regions in brains of patients who had died with HD. We therefore suggest that the mechanism of neuronal cell death in both HD and a transgenic mouse model of HD is neither by apoptosis nor by necrosis.

Also flagged:endosulfansulfurTween 80Degradationendosulfateendosulfan monoaldehyde
Journal Article 2000-07-01 No Snippets Sutherland TD, Horne I, Lacey MJ, Harcourt RL, Russell RJ, Oakeshott JG.
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An endosulfan-degrading mixed bacterial culture was enriched from soil with a history of endosulfan exposure. Enrichment was obtained by using the insecticide as the sole source of sulfur. Chemical hydrolysis was minimized by using strongly buffered culture medium (pH 6.6), and the detergent Tween 80 was included to emulsify the insecticide, thereby increasing the amount of endosulfan in contact with the bacteria. No growth occurred in control cultures in the absence of endosulfan. Degradation of the insecticide occurred concomitant with bacterial growth. The compound was both oxidized and hydrolyzed. The oxidation reaction favored the alpha isomer and produced endosulfate, a terminal pathway product. Hydrolysis involved a novel intermediate, tentatively identified as endosulfan monoaldehyde on the basis of gas chromatography-mass spectrometry and chemical derivatization results. The accumulation and decline of metabolites suggest that the parent compound was hydrolyzed to the putative monoaldehyde, thereby releasing the sulfite moiety required for growth. The monoaldehyde was then oxidized to endosulfan hydroxyether and further metabolized to (a) polar product(s). The cytochrome P450 inhibitor, piperonyl butoxide, did not prevent endosulfan oxidation or the formation of other metabolites. These results suggest that this mixed culture is worth investigating as a source of endosulfan-hydrolyzing enzymes for use in enzymatic bioremediation of endosulfan residues.

Also flagged:iron overload diseasehereditary haemochromatosisHHmajor histocompatibility complexMHCclass I
Journal Article 2000-07-01 ✓ 5 Snippets Drakesmith H, Townsend A.
In-Text Gene Mentions

The iron overload disease hereditary haemochromatosis (HH) occurs in about 1 in 300 Caucasians; the protein mutated in this disorder is termed HFE.

Whether the interaction between HFE and TfR explains the pathogenesis of HH is not so clear.

iron overload disease hereditary haemochromatosis (HH) occurs in about 1 in 300 Caucasians; the protein mutated in this disorder is termed HFE

iron overload disease hereditary haemochromatosis (HH) occurs in about 1 in 300 Caucasians; the protein mutated in this disorder is termed HFE.(1) HFE is homologous to major histocompatibility complex (MHC) class I proteins, but unlike MHC class I molecules, HFE does not present peptides to T cells.(2) The transferrin

iron overload disease hereditary haemochromatosis (HH) occurs in about 1 in 300 Caucasians; the protein mutated in this disorder is termed HFE.(1) HFE is homologous to major histocompatibility complex (MHC) class I proteins, but unlike MHC class I molecules, HFE does not present peptides to T cells.(2) The transferrin receptor (TfR

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The iron overload disease hereditary haemochromatosis (HH) occurs in about 1 in 300 Caucasians; the protein mutated in this disorder is termed HFE.(1) HFE is homologous to major histocompatibility complex (MHC) class I proteins, but unlike MHC class I molecules, HFE does not present peptides to T cells.(2) The transferrin receptor (TfR) is a ligand for HFE, and the crystal structure of the HFE-TfR complex has been determined.(3) The many interesting features of this structure illustrate the diverse roles of the MHC fold in nature and clarify how HFE affects TfR function. Whether the interaction between HFE and TfR explains the pathogenesis of HH is not so clear.

Also flagged:tumorstumorinvasive ductal pancreatic carcinomaspolymerasep53DPC4
Journal Article 2000-07-01 ✓ 1 Snippet Heinmöller E, Dietmaier W, Zirngibl H, Heinmöller P, Scaringe W, Jauch KW, Hofstädter F, Rüschoff J.
In-Text Gene Mentions

DCC

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Little or no data exist concerning the inactivation of tumor suppressor genes in intraductal lesions surrounding invasive ductal pancreatic carcinomas. Using a novel improved primer extension and preamplification polymerase chain reaction, we analyzed microdissected paraffin-embedded specimens of pancreatic carcinoma (n = 29) and their corresponding pancreatic intraductal lesions (PIL, n = 331) for loss of heterozygosity (LOH) of p16(INK4), DPC4, and p53 by microsatellite analysis and for p53 protein by immunohistochemistry. LOH at the p16(INK4) locus (9p21) was found in nine of 22 informative tumors (41%), in 15 of 25 tumors (60%) at the DPC4 locus (18q21.1), and in 22 of 27 tumors (81%) at the p53 locus (17p13). Homozygous deletions of p16(INK4) and DPC4 were found in eight of 22 (36%) and four of 25 tumors (16%), respectively. Furthermore, 24 of 29 tumors (83%) revealed considerable intratumoral genetic heterogeneity. In 165 of 277 PILs (60%) having suitable DNA for microsatellite analysis, alterations in at least one tumor suppressor gene were found. In individual PILs, up to three alterations were detected, and p53 LOH occurred even in morphologically normal-appearing ductal epithelium near the tumor. Although deletions of all three tumor suppressor genes were found in PILs without nuclear atypia, there was a tendency toward earlier LOH of p16(INK4) compared to DPC4 and p53 in these lesions. LOH in tumors accompanied positive p53 immunohistochemistry in 81% but only in 38% in PILs.

Also flagged:ring-finger proteinsari-1ari-2membranemetamorphosismyogenesis
Journal Article 2000-07-01 No Snippets Aguilera M, Oliveros M, Martínez-Padrón M, Barbas JA, Ferrús A.
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We report the identification and functional characterization of ariadne-1 (ari-1), a novel and vital Drosophila gene required for the correct differentiation of most cell types in the adult organism. Also, we identify a sequence-related gene, ari-2, and the corresponding mouse and human homologues of both genes. All these sequences define a new protein family by the Acid-rich, RING finger, B-box, RING finger, coiled-coil (ARBRCC) motif string. In Drosophila, ari-1 is expressed throughout development in all tissues. The mutant phenotypes are most noticeable in cells that undergo a large and rapid membrane deposition, such as rewiring neurons during metamorphosis, large tubular muscles during adult myogenesis, and photoreceptors. Occasional survivors of null alleles exhibit reduced life span, motor impairments, and short and thin bristles. Single substitutions at key cysteines in each RING finger cause lethality with no survivors and a drastic reduction of rough endoplasmic reticulum that can be observed in the photoreceptors of mosaic eyes. In yeast two-hybrid assays, the protein ARI-1 interacts with a novel ubiquitin-conjugating enzyme, UbcD10, whose sequence is also reported here. The N-terminal RING-finger motif is necessary and sufficient to mediate this interaction. Mouse and fly homologues of both ARI proteins and the Ubc can substitute for each other in the yeast two-hybrid assay, indicating that ARI represents a conserved novel mechanism in development. In addition to ARI homologues, the RBR signature is also found in the Parkinson-disease-related protein Parkin adjacent to an ubiquitin-like domain, suggesting that the study of this mechanism could be relevant for human pathology.

Also flagged:breast cancertumoursanthracyclinetumourbreast cancersER
Journal Article 2000-07-01 No Snippets Cameron DA, Gregory WM, Bowman A, Anderson ED, Levack P, Forouhi P, Leonard RC.
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Although clinical response to primary chemotherapy in stage II and III breast cancer is associated with a survival advantage, it is the degree of pathological response in the breast and ipsilateral axilla that best identifies patients with a good long-term outcome. A mathematical model of the initial response of 39 locally advanced tumours to anthracycline-based primary chemotherapy has been previously shown to predict subsequent clinical tumour size. This model allows for the possibility of primary resistant disease, the presence of which should therefore be associated with a worse outcome. This study reports the application of this model to an additional five patients with locally advanced breast cancer, as well as to 63 patients with operable breast cancer, and confirms the biological reality of the model parameters for these 100 breast cancers treated with primary anthracycline-based chemotherapy. The tumours that responded to chemotherapy had higher cell-kill (P < 0.0005), lower resistance (P < 0.0001) and slower tumour regrowth (P < 0.002). Furthermore, ER-negative tumours had higher cell-kill (P < 0.05), as compared with ER-positive tumours. All patients with a pathological complete response had zero resistance according to the model. Furthermore, the long-term implication of chemo-resistant disease was demonstrated by survival analysis of these two groups of patients. At a median follow-up of 3.7 years, there was a statistically significantly worse survival for the 37 patients with locally advanced breast cancer identified by the model to have more than 8% primary resistant tumour (P < 0.003). The specificity of this putative prognostic indicator was confirmed in the 63 patients presenting with operable disease where, at a median follow-up of 7.7 years, those women with a resistant fraction of greater than 8% had a significantly worse survival (P < 0.05). Application of this model to patients treated with neoadjuvant chemotherapy may allow earlier identification of clinically significant resistance and permit intervention with alternative non-cross-resistant therapies such as taxoids.

Also flagged:reverse transcriptaseRTnucleotideFV LeidenHHnucleotides
Journal Article 2000-07-01 ✓ 1 Snippet Pastinen T, Raitio M, Lindroos K, Tainola P, Peltonen L, Syvänen AC.
In-Text Gene Mentions

hemochromatosis

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This study describes a practical system that allows high-throughput genotyping of single nucleotide polymorphisms (SNPs) and detection of mutations by allele-specific extension on primer arrays. The method relies on the sequence-specific extension of two immobilized allele-specific primers that differ at their 3'-nucleotide defining the alleles, by a reverse transcriptase (RT) enzyme at optimized reaction conditions. We show the potential of this simple one-step procedure performed on spotted primer arrays of low redundancy by generating over 8000 genotypes for 40 mutations or SNPs. The genotypes formed three easily identifiable clusters and all known genotypes were assigned correctly. Higher degrees of multiplexing will be possible with this system as the power of discrimination between genotypes remained unaltered in the presence of over 100 amplicons in a single reaction. The enzyme-assisted reaction provides highly specific allele distinction, evidenced by its ability to detect minority sequence variants present in 5% of a sample at multiple sites. The assay format based on miniaturized reaction chambers at standard 384-well spacing on microscope slides carrying arrays with two primers per SNP for 80 samples results in low consumption of reagents and makes parallel analysis of a large number of samples convenient. In the assay one or two fluorescent nucleotide analogs are used as labels, and thus the genotyping results can be interpreted with presently available array scanners and software. The general accessibility, simple set-up, and the robust procedure of the array-based genotyping system described here will offer an easy way to increase the throughput of SNP typing in any molecular biology laboratory.

Also flagged:chromosomeDpp6HdhHuntington diseaseGabrb1chromosomes
Journal Article 2000-07-01 No Snippets Schimenti JC, Libby BJ, Bergstrom RA, Wilson LA, Naf D, Tarantino LM, Alavizadeh A, Lengeling A, Bucan M.
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Chromosome deletions have several applications in the genetic analysis of complex organisms. They can be used as reagents in region-directed mutagenesis, for mapping of simple or complex traits, or to identify biological consequences of segmental haploidy, the latter being relevant to human contiguous gene syndromes and imprinting. We have generated three deletion complexes in ES (Embryonic Stem) cells that collectively span approximately 40 cM of proximal mouse chromosome 5. The deletion complexes were produced by irradiation of F(1) hybrid ES cells containing herpes simplex virus thymidine kinase genes (tk) integrated at the Dpp6, Hdh (Huntington disease locus), or Gabrb1 loci, followed by selection for tk-deficient clones. Deletions centered at the adjacent Hdh and Dpp6 loci ranged up to approximately 20 cM or more in length and overlapped in an interdigitated fashion. However, the interval between Hdh and Gabrb1 appeared to contain a locus haploinsufficient for ES cell viability, thereby preventing deletions of either complex from overlapping. In some cases, the deletions resolved the order of markers that were previously genetically inseparable. A subset of the ES cell-bearing deletions was injected into blastocysts to generate germline chimeras and establish lines of mice segregating the deletion chromosomes. At least 11 of the 26 lines injected were capable of producing germline chimeras. In general, those that failed to undergo germline transmission bore deletions larger than the germline-competent clones, suggesting that certain regions of chromosome 5 contain haploinsufficient developmental genes, and/or that overall embryonic viability is cumulatively decreased as more genes are rendered hemizygous. Mice bearing deletions presumably spanning the semidominant hammertoe locus (Hm) had no phenotype, suggesting that the classic allele is a dominant, gain-of-function mutation. Overlapping deletion complexes generated in the fashion described in this report will be useful as multipurpose genetic tools and in systematic functional mapping of the mouse genome.

Also flagged:Alpha-synucleinpolyglutamineHuntington's diseaseneurodegenerative disordersnucleuschaperone
Journal Article 2000-07-01 No Snippets Charles V, Mezey E, Reddy PH, Dehejia A, Young TA, Polymeropoulos MH, Brownstein MJ, Tagle DA.
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Polyglutamine expansions in proteins are implicated in at least eight inherited neurodegenerative disorders, including Huntington's disease. These mutant proteins can form aggregates within the nucleus and processes of neurons possibly due to misfolding of the proteins. Polyglutamine aggregates are ubiquitinated and sequester molecular chaperone proteins and proteasome components. To investigate other protein components of polyglutamine aggregates, cerebral cortex and striata from patients with Huntington's disease and full-length cDNA transgenic mouse models for this disease were examined immunohistochemically for alpha-synuclein reactivity. Our findings demonstrate that alpha-synuclein can be used as a marker for huntingtin polyglutamine aggregates in both human and mice. Moreover in the HD transgenic mice, the intensity of immunoreactivity increases with age. The significance of recruitment of alpha-synuclein into huntingtin aggregates and its translocation away from the synapses remains to be determined. We propose that aberrant interaction of mutant huntingtin with other proteins, including alpha-synuclein, may influence disease progression.

Also flagged:APCovarian cancerBRCA1cancerbreast
Journal Article 2000-07-01 No Snippets Gershoni-Baruch R, Patael Y, Dagan, Figer A, Kasinetz L, Kadouri E, Bruchim Bar Sade R, Friedman E.
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The frequency of the APC I1307K mutation and its association with disease pattern was examined in 996 Ashkenazi women consisting of individuals with either sporadic (n = 382) or hereditary (n = 143) breast and/or ovarian cancer; asymptomatic BRCA1/2 mutation carriers (185delAG, 5382insC and 6174delT) (n= 53) and healthy controls (n= 418). The I1307K allele was equally distributed among women with sporadic (17/382; 4.6%) and inherited (10/143; 7%) breast and/or ovarian cancer irrespective of their being diagnosed before or after 42 years of age and among asymptomatic (7/53; 13.2%) and cancer manifesting BRCA1/2 carriers (10/143; 7%). Taken together, the prevalence of the I1307K allele was significantly higher in BRCA1/2 carriers compared to non-BRCA1/2 carriers (17/196; 8.7% and 40/800, 5%; respectively). The high prevalence of the I1307K allele among BRCA1/2 carriers is not associated with increased cancer risk but seems to be genetically connected because of Jewish ancestry.

Also flagged:breast cancerTissue factorTFcoagulationcancertumour
Journal Article 2000-07-01 No Snippets Ueno T, Toi M, Koike M, Nakamura S, Tominaga T.
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Tissue factor (TF), an initiator of the extrinsic coagulation cascade, is expressed in a wide range of cancer cells and plays important roles in cancer progression and metastasis. Recently, the intracellular function of TF has been revealed to be involved in cancer invasion, independent of the blood coagulation pathway. To evaluate the clinical significance of TF expression, we performed an enzyme-linked immunosorbent assay (ELISA) in the plasma of 67 breast cancer patients and immunohistochemistry in 213 breast cancer tissues. In the ELISA study, we showed an up-regulation of plasma TF concentration in breast cancer patients compared with normal controls. Immunohistochemistry demonstrated that TF was expressed in tumour cells and stromal cells and tumour TF expression closely correlated with stromal TF expression (P = 0.0005). The concentration of plasma TF was associated with tissue TF expression in both tumour and stroma. The multivariate analysis demonstrated that tumour TF expression was an independent prognostic indicator for overall survival (P = 0.0452). Our data show that plasma TF concentration reflects tissue TF expression and tumour TF expression can provide some predictive value for prognosis and distant metastasis, which indicates the importance of TF function in tumour progression.

Also flagged:PTIPPax2transcription factorstissue developmentbindingBRCA1
Journal Article 2000-07-01 ✓ 1 Snippet Lechner MS, Levitan I, Dressler GR.
In-Text Gene Mentions

DCC

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The Pax gene family encodes transcription factors essential for organ and tissue development in higher eukaryotes. Pax proteins are modular with an N-terminal DNA binding domain, a C-terminal transcription activation domain, and a transcription repression domain called the octapeptide. How these domains interact with the cellular machinery remains unclear. In this report, we describe the isolation and characterization of a novel gene and its encoded protein, PTIP, which binds to the activation domain of Pax2 and other Pax proteins. PTIP binds to Pax2 in vitro, in the yeast two-hybrid assay and in tissue culture cells. The binding of PTIP to Pax2 is inhibited by the octapeptide repression domain. The PTIP protein contains five BRCT domains, first identified in BRCA1 and other nuclear proteins involved in DNA repair/recombination or cell cycle control. Pax2 and PTIP co-localize in the cell nucleus to actively expressed chromatin and the nuclear matrix fraction. For the first time, these results point to a link between Pax transcription factors and active chromatin.

Also flagged:head and neck squamous cell carcinomaofhead and neck squamous cell carcinomastumorDPC4Smad4
Journal Article 2000-07-01 ✓ 2 Snippets Takebayashi S, Ogawa T, Jung KY, Muallem A, Mineta H, Fisher SG, Grenman R, Carey TE.
In-Text Gene Mentions

Several putative tumor suppressor genes, such as DCC, DPC4/Smad4, and MADR2/Smad2, are mapped to 18q, but thus far, the important gene locus in HNSCC is not known.

…genes, such asDCC, DPC4/Smad4, and MADR2/Smad2,…

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Loss of heterozygosity (LOH) on 18q predicts poor survival in head and neck squamous cell carcinomas (HNSCCs). Several putative tumor suppressor genes, such as DCC, DPC4/Smad4, and MADR2/Smad2, are mapped to 18q, but thus far, the important gene locus in HNSCC is not known. To identify possible gene loci on 18q, we performed LOH studies using tumor DNA from 57 HNSCC primary tumor cell lines and DNA isolated from fibroblasts or lymphoblastoid cells from the same patients. Forty-two highly polymorphic microsatellite markers spaced not more than 5 cM apart (mean distance, 1.82 cM) spanning the region from D18S44 in 18q11.1 to D18S1141 in 18q23 were used. D18S71 in 18p11.21 on 18p was also used to determine whether the short arm was retained. Forty-three of 57 (75%) HNSCC lines showed LOH or isolated allelic imbalance (AI) for at least one locus on 18q. Although many of the cell lines had large distal 18q deletions with a breakpoint between 18q11.1 and 18q12.2 to qter, three loci were identified that were lost in 70% or more of the cases. The minimally lost regions (MLRs) range in size from 1.5-15.79 cM. The most proximal is centered on D18S39 (1.56 cM) in band 18q21.1, with LOH or isolated AI in 28 of 38 (74%) of informative cases. The largest (15.8 cM) begins at D18S61 (28 of 40; 70%) in band 18q22.2 and extends through D18S50 in 18q23. The third is centered on D18S70 (30 of 40; 75%) in band 18q23 (3.67 cM). Of these MLRs, only the one centered on D18S39 has been implicated previously in HNSCC. D18S70, the most frequently lost marker, was the only marker consistently lost in three tumor cell lines with very minimal losses, UM-SCC-19, UM-SCC-67, and UM-SCC-73A. In addition, UM-SCC-91 exhibited AI only at this locus, and UT-SCC-4 had AI at D18S70 and D18S39 only. Close physical mapping of these three regions may pinpoint one or more previously unidentified tumor suppressor genes.

Also flagged:hepatocellular carcinomahereditary hemochromatosistumorcapsule
Journal Article 2000-07-01 ✓ 5 Snippets Pirisi M, Toniutto P, Uzzau A, Fabris C, Avellini C, Scott C, Apollonio L, Beltrami CA, Bresadola F.
In-Text Gene Mentions

Aggressive hepatocellular carcinoma (HCC) complicates frequently hereditary hemochromatosis, a disease for which a strong candidate gene, named HFE, has recently been identified.

Carriage of HFE mutations and outcome of surgical resection for hepatocellular carcinoma in cirrhotic patients.

Patients with HCC who are heterozygotes for mutations in the HFE gene might have distinct features and a distinct disease course.<h4>Methods</h4>The presence of the 2 mutations associated with hereditary hemochromatosis (C282Y and H63D) was sought by restriction fragment length polymorphism in 61 cirrhotic patients (46 males and 15 females) who underwent resection for HCC at a single institution.<h4>Results</h4>There were 4 heterozygotes for the C282Y mutation and 6 homozygotes + 20 heterozygotes for the H63D mutation, with no compound heterozygotes.

The negative effect on survival that resulted from possessing >/= 1 HFE mutated allele was maintained even after adjustment for gender, age, presence of tumor capsule, presence of comorbid factors, Okuda stage, Edmonson grading, and number of lesions (P = 0.01).<h4>Conclusions</h4>Testing for HFE mutations may help identify HCC patients with dismal prognoses for whom surgical resection may not represent the best treatment option.

…Carriage ofHFEmutations and outcome…

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<h4>Background</h4>Aggressive hepatocellular carcinoma (HCC) complicates frequently hereditary hemochromatosis, a disease for which a strong candidate gene, named HFE, has recently been identified. Patients with HCC who are heterozygotes for mutations in the HFE gene might have distinct features and a distinct disease course.<h4>Methods</h4>The presence of the 2 mutations associated with hereditary hemochromatosis (C282Y and H63D) was sought by restriction fragment length polymorphism in 61 cirrhotic patients (46 males and 15 females) who underwent resection for HCC at a single institution.<h4>Results</h4>There were 4 heterozygotes for the C282Y mutation and 6 homozygotes + 20 heterozygotes for the H63D mutation, with no compound heterozygotes. Carriage of >/= 1 HFE mutated allele was significantly more frequent in HCC patients than in 149 control subjects (44% vs. 29%, P = 0.005). Among C282Y heterozygotes, 3 of 4 were female, compared with 12 of 57 wild-type carriers (P = 0.015); no gender distribution existed among patients carrying H63D alleles (6 of 26 vs. 9 of 35, P = 0.813). Survival was longer for patients with wild-type HFE than for those with mutated HFE (67% vs. 22% at 3 years; hazard ratio = 0.42, 95% confidence interval = 0.21-0.80) (P < 0.01). The negative effect on survival that resulted from possessing >/= 1 HFE mutated allele was maintained even after adjustment for gender, age, presence of tumor capsule, presence of comorbid factors, Okuda stage, Edmonson grading, and number of lesions (P = 0.01).<h4>Conclusions</h4>Testing for HFE mutations may help identify HCC patients with dismal prognoses for whom surgical resection may not represent the best treatment option.

Also flagged:5-HT transporter5-HT1A5-HT3 receptors5-HT1A receptors5-HT transporterscitalopram
Journal Article 2000-07-01 ✓ 4 Snippets Chen F, Lawrence AJ.
In-Text Gene Mentions

<h4>Background</h4>The neuroanatomical profiles of 5-HT1A receptors, 5-HT3 receptors, and 5-HT transporters (5-HTT) in the brain of the Fawn-Hooded (FH) rat, particularly mesocorticolimbic regions, are not fully elucidated.<h4>Methods</h4>By means of in vitro quantitative autoradiography, we used [3H]citalopram, [3H]8-OH-DPAT, and [3H]GR65630 to label 5-HTT, 5-HT1A receptors, and 5-HT3 receptors in the brain of alcohol-naïve FH rats, Wistar-Kyoto (WKY) rats, and FH rats given free access to 5% ethanol and/or after 24 to 48 hr withdrawal.<h4>Results and conclusions</h4>In alcohol-naïve rats, FH rats displayed significantly higher (p < 0.05) densities of [3H]citalopram binding in the nucleus accumbens (+30%), lateral septum (+37%), ventral pallidum (+21%), and ventral tegmental area (+24%), as well as an increased binding of [3H]8-OH-DPAT to 5-HT1A receptors in the frontal and parietal cortex (+33%), occipital and temporal cortex (+25%), and hippocampal CA3 region (+31%), compared with WKY rats, whereas both strains exhibited comparable [3H]GR65630 binding to 5-HT3 receptors.

…and 5-HT transporters (5-HTT) in the brain…

…[3H]GR65630 to label5-HTT, 5-HT1A receptors, and…

…ethanol challenges, whereas5-HTTare apparently insensitive.…

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<h4>Background</h4>The neuroanatomical profiles of 5-HT1A receptors, 5-HT3 receptors, and 5-HT transporters (5-HTT) in the brain of the Fawn-Hooded (FH) rat, particularly mesocorticolimbic regions, are not fully elucidated.<h4>Methods</h4>By means of in vitro quantitative autoradiography, we used [3H]citalopram, [3H]8-OH-DPAT, and [3H]GR65630 to label 5-HTT, 5-HT1A receptors, and 5-HT3 receptors in the brain of alcohol-naïve FH rats, Wistar-Kyoto (WKY) rats, and FH rats given free access to 5% ethanol and/or after 24 to 48 hr withdrawal.<h4>Results and conclusions</h4>In alcohol-naïve rats, FH rats displayed significantly higher (p < 0.05) densities of [3H]citalopram binding in the nucleus accumbens (+30%), lateral septum (+37%), ventral pallidum (+21%), and ventral tegmental area (+24%), as well as an increased binding of [3H]8-OH-DPAT to 5-HT1A receptors in the frontal and parietal cortex (+33%), occipital and temporal cortex (+25%), and hippocampal CA3 region (+31%), compared with WKY rats, whereas both strains exhibited comparable [3H]GR65630 binding to 5-HT3 receptors. Compared with control FH (naive) rats, chronic ethanol consumption significantly decreased (p < 0.(15)[3H]8-OH-DPAT binding in the frontal and parietal cortex (-15%) but significantly increased binding (p < 0.05) in the entorhinal cortex (+25%), retrosplenial granular cortex (+20%), and hippocampal CA1 (+14%) and CA3 regions (+18%). Moreover, ethanol withdrawal induced the same extent of increased [3H]8-OH-DPAT binding in the entorhinal and retrosplenial cortex as seen in FH (chronic) rats. In contrast, [3H]8-OH-DPAT binding in the hippocampal CA1 and CA3 regions was decreased by -9% and -20% from the level of chronic ethanol-treated FH rat (p < 0.05) and returned to the control level seen in FH (naïve) rats.<h4>Significance</h4>The elevated 5-HT transporters and 5-HT1A receptors in the mesocorticolimbic areas in FH rats may reflect a potential innate altered transmission at serotonergic synapses, which possibly may affect the high intake of alcohol in FH rats. The region-specific alterations of 5-HT1A receptors in FH rat brain after ethanol challenges suggest that 5-HT1A receptors are sensitive to ethanol challenges, whereas 5-HTT are apparently insensitive.

Also flagged:ironchronic liver diseaseHereditary hemochromatosisHHliver diseasesgranules
Journal Article 2000-07-01 ✓ 5 Snippets Brunt EM, Olynyk JK, Britton RS, Janney CG, Di Bisceglie AM, Bacon BR.
In-Text Gene Mentions

This study assessed liver biopsies containing stainable iron from 103 patients with various liver diseases; clinical information included hepatic iron concentration and HFE genotype (C282Y, H63D).

The use of histological evaluation for iron deposition is simple, assists in expanding information communicated from histopathologic observations, and may be clinically useful in determining the necessity of further evaluation of HFE genotype in subjects with histological evidence of hepatic iron overload.

Hereditary hemochromatosis (HH) results in hepatic iron overload and is associated with 2 missense mutations in the HFE gene.

Hereditary hemochromatosis (HH) results in hepatic iron overload and is associated with 2 missense mutations in the HFE

liver diseases; clinical information included hepatic iron concentration and HFE

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<h4>Objective</h4>Hepatic iron overload is observed in many forms of chronic liver disease. Hereditary hemochromatosis (HH) results in hepatic iron overload and is associated with 2 missense mutations in the HFE gene. The aim of this study was to define the usefulness of the histological pattern of iron deposition in determining the probability of an iron-loaded patient having HFE-related iron overload.<h4>Methods</h4>This study assessed liver biopsies containing stainable iron from 103 patients with various liver diseases; clinical information included hepatic iron concentration and HFE genotype (C282Y, H63D). The biopsies were evaluated using a reproducible histological scoring system for iron deposition. Three separate components of histological iron deposition were recorded: 1) pattern (primarily hepatocellular with a zonal gradient, or reticuloendothelial without an obvious zonal gradient), 2) pattern score to denote the extent of iron within the acinus, and 3) quantitation grade of iron granules within affected hepatocytes.<h4>Results</h4>The predominantly hepatocellular pattern (HH pattern) was observed in 72 biopsies of which only 42 were from patients homozygous for the C282Y mutation, indicating that this pattern alone cannot be used as a surrogate marker for HH genotype. The predominantly reticuloendothelial pattern (non-HH pattern) was observed in the remaining 31 patients, none of whom was compound heterozygous or homozygous for the C282Y mutation (negative predictive value: 100%). Thus, the non-HH, reticuloendothelial pattern reliably predicts the absence of homozygosity for the C282Y mutation.<h4>Conclusions</h4>The use of histological evaluation for iron deposition is simple, assists in expanding information communicated from histopathologic observations, and may be clinically useful in determining the necessity of further evaluation of HFE genotype in subjects with histological evidence of hepatic iron overload.

Also flagged:hereditary haemochromatosispolymerase
Journal Article 2000-07-01 ✓ 2 Snippets Medintz I, Wong WW, Sensabaugh G, Mathies RA.
In-Text Gene Mentions

Using fluorescently labeled allele-specific primers, the S65C (193A--&gt;T) substitution associated with hereditary haemochromatosis in the HFE gene is genotyped.

…haemochromatosis in theHFEgene is genotyped.…

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A single nucleotide polymorphism (SNP) typing assay is developed and evaluated on a microfabricated capillary array electrophoresis system. Using fluorescently labeled allele-specific primers, the S65C (193A-->T) substitution associated with hereditary haemochromatosis in the HFE gene is genotyped. The covalently labeled polymerase chain reaction (PCR) products are separated on a microfabricated radial capillary array electrophoresis microplate using nondenaturing gel media in under two minutes. Detection is accomplished with a laser-excited rotary confocal scanner. The Rox-labeled A-allele specific amplicon (211 bp) is differentiated from the R110-labeled T-allele specific amplicon (201 bp) by both size and color. This study demonstrates the feasibility of using allele-specific PCR with covalently labeled primers for high speed fluorescent SNP typing on microfabricated radial capillary array electrophoresis microplates.

Also flagged:serotonin5-HT1A5-HT1B receptors5-HT transporter5-hydroxytryptamineextracellular space
Journal Article 2000-07-01 ✓ 5 Snippets Fabre V, Beaufour C, Evrard A, Rioux A, Hanoun N, Lesch KP, Murphy DL, Lanfumey L, Hamon M, Martres MP.
In-Text Gene Mentions

By taking up serotonin (5-hydroxytryptamine, 5-HT) released in the extracellular space, the 5-HT transporter (5-HTT) regulates central 5-HT neurotransmission.

…the 5-HT transporter (5-HTT) regulates central 5-HT…

…forebrain areas of5-HTT-/- vs. 5-HTT+/+ mice.…

…of 5-HTT-/- vs.5-HTT+/+ mice.…

…were noted in5-HTT+/- mice compared with…

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By taking up serotonin (5-hydroxytryptamine, 5-HT) released in the extracellular space, the 5-HT transporter (5-HTT) regulates central 5-HT neurotransmission. Possible adaptive changes in 5-HT neurotransmission in knock-out mice that do not express the 5-HT transporter were investigated with special focus on 5-HT1A and 5-HT1B receptors. Specific labelling with radioligands and antibodies, and competitive RT-PCR, showed that 5-HT1A receptor protein and mRNA levels were significantly decreased in the dorsal raphe nucleus (DRN), increased in the hippocampus and unchanged in other forebrain areas of 5-HTT-/- vs. 5-HTT+/+ mice. Such regional differences also concerned 5-HT1B receptors because a decrease in their density was found in the substantia nigra (-30%) but not the globus pallidus of mutant mice. Intermediate changes were noted in 5-HTT+/- mice compared with 5-HTT+/+ and 5-HTT-/- animals. Quantification of [35S]GTP-gamma-S binding evoked by potent 5-HT1 receptor agonists confirmed such changes as a decrease in this parameter was noted in the DRN (-66%) and the substantia nigra (-30%) but not other brain areas in 5-HTT-/- vs. 5-HTT+/+ mice. As expected from actions mediated by functional 5-HT1A and 5-HT1B autoreceptors, a decrease in brain 5-HT turnover rate after i.p. administration of ipsapirone (a 5-HT1A agonist), and an increased 5-HT outflow in the substantia nigra upon local application of GR 127935 (a 5-HT1B/1D antagonist) were observed in 5-HTT+/+ mice. Such effects were not detected in 5-HTT-/- mice, further confirming the occurrence of marked alterations of 5-HT1A and 5-HT1B autoreceptors in these animals.

Also flagged:signal transductionbindingneurotrophin receptorandrogen receptorARcolorectal cancer
Journal Article 2000-07-01 ✓ 5 Snippets Mehlen P, Bredesen DE.
In-Text Gene Mentions

androgen receptor (AR), DCC (deleted in colorectal cancer

DCC (deleted in colorectal cancer), and RET (rearranged during transfection) demonstrate effects that are more adequately explained when these are considered to be dependence

DCC (deleted in colorectal cancer

androgen receptor (AR), DCC (deleted in colorectal cancer), and RET (rearranged during transfection) demonstrate effects that are more adequately explained when these are considered to be dependence

…androgen receptor (AR),DCC(deleted in colorectal…

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The dependence receptor notion was based on the observation that the effects of a number of receptors that function in both nervous system development and tumorigenesis (especially metastasis) cannot be explained simply by a positive effect of signal transduction induced by ligand binding. Receptors such as the common neurotrophin receptor p75NTR, the androgen receptor (AR), DCC (deleted in colorectal cancer), and RET (rearranged during transfection) demonstrate effects that are more adequately explained when these are considered to be dependence receptors. These receptors show two distinct forms of signal transduction depending on their respective ligand availability: in the presence of their ligands, they transduce a signal for either proliferation or differentiation; however, they are not inactive in the absence of their ligands, but rather induce an active signal for cell death. Such receptors thus create a cellular state of dependence on their ligands, the loss of ligand availability inducing cell suicide or enhancing the likelihood of cellular suicide. This new concept is reviewed here enlightening the molecular mechanisms of these receptors and their potential relevance in vivo in the development of the nervous system and in the control of tumorigenesis.

Also flagged:Autoimmune hepatitisMyasthenia gravisautoimmune diseaseantibodythymomaMyasthenia
Journal Article 2000-07-01 ✓ 1 Snippet Han YS, Kim BH, Kim TH, Dong SH, Kim HJ, Chang YW, Lee JI, Rin-Chang, Kim YW, Park JC.
In-Text Gene Mentions

…including Wilson’s disease,hemochromatosisand alpha1-antitrypsin deficie…

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Myasthenia gravis is an autoimmune disease that results from an antibody-mediated reaction and occurs with thymoma in 15% of patients. It is very rarely associated with autoimmune hepatitis. Four cases of myasthenia gravis with autoimmune hepatitis have been reported in the world. We recently experienced a case of 30-year-old man with myasthenia gravis associated with thymoma and autoimmune hepatitis. This condition is the first case that has not been reported previously in Korea. We report this rare condition along with a brief review of the literature.

Also flagged:lung cancerschromosometumor suppressorlung cancersmall cell lung carcinomasnon-small cell lung carcinomas
Journal Article 2000-07-01 ✓ 5 Snippets Kohno T, Sato T, Takakura S, Takei K, Inoue K, Nishioka M, Yokota J.
In-Text Gene Mentions

Therefore, genetic alterations of DCC are infrequent; however, the levels of DCC expression vary among lung cancer cells, in particular, between SCLCs and NSCLCs.

Mutation and expression of the DCC gene in human lung cancer.

Since the DCC candidate tumor suppressor gene has been mapped in this region, mutation and expression of the DCC gene were examined in 46 lung cancer cell lines, consisting of 14 small cell lung carcinomas (SCLCs) and 32 non-small cell lung carcinomas (NSCLCs), to elucidate the pathogenetic significance of DCC alterations in human lung carcinogenesis.

The DCC gene was expressed in 11 (24%) of the 46 cell lines, and the incidence of DCC expression was significantly higher in SCLCs (7/14, 50%) than in NSCLCs (4/32, 13%) (P = .01, Fisher's exact test).

The present result also suggests that DCC expression is associated with some properties of SCLCs, such as a neuroendocrine (NE) feature.

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Chromosome 18q is frequently deleted in lung cancers, and a common region of 18q deletions was mapped to chromosome 18q21. Since the DCC candidate tumor suppressor gene has been mapped in this region, mutation and expression of the DCC gene were examined in 46 lung cancer cell lines, consisting of 14 small cell lung carcinomas (SCLCs) and 32 non-small cell lung carcinomas (NSCLCs), to elucidate the pathogenetic significance of DCC alterations in human lung carcinogenesis. A heterozygous missense mutation was detected in a NSCLC cell line, Ma26, while homozygous deletion was not detected in any of the cell lines. The DCC gene was expressed in 11 (24%) of the 46 cell lines, and the incidence of DCC expression was significantly higher in SCLCs (7/14, 50%) than in NSCLCs (4/32, 13%) (P = .01, Fisher's exact test). Therefore, genetic alterations of DCC are infrequent; however, the levels of DCC expression vary among lung cancer cells, in particular, between SCLCs and NSCLCs. The present result does not implicate DCC as a specific mutational target of 18q deletions in human lung cancer; however, it suggests that DCC is a potential target of inactivation by genetic defects including intron or promoter mutations and/or epigenetic alterations. The present result also suggests that DCC expression is associated with some properties of SCLCs, such as a neuroendocrine (NE) feature.

Also flagged:intravascular coagulationwarfarinheparincoagulationheparinsthrombin
Journal Article 2000-07-01 ✓ 1 Snippet Porcari AR, Chi L, Leadley R.
In-Text Gene Mentions

…which SR90107A/ORG31540, anantithrombin-III-dependent pentasaccharide and…

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Over the years, pharmacological intervention to prevent undesired intravascular coagulation and the associated detrimental effects has been a clinical challenge. The first generation of anticoagulant agents, warfarin and unfractionated heparin (UFH), involve indirect mechanisms of inhibiting the coagulation cascade. Fractionated, or low-molecular weight, heparins (LMWHs) are more selective for coagulation Factor Xa (FXa) over thrombin (FIIa). LMWHs also utilise an indirect mechanism of inhibition and have improved pharmacokinetic, pharmacodynamic and therapeutic profiles over UFH. The success of LMWHs, along with the pivotal location of FXa in the coagulation cascade, has prompted interest in the discovery and development of selective FXa inhibitors. There are two general classes of FXa inhibitors in development, of which SR90107A/ORG31540, an antithrombin-III-dependent pentasaccharide and DX-9065a, a small molecule direct FXa inhibitor, have published clinical data. SR90107A/ORG31540 and DX-9065a offer safe, predictable pharmacokinetic and pharmacodynamic profiles when administered subcutaneously and intravenously, respectively, to healthy volunteers and appear to be progressing through clinical development. The purpose of this review is to compile and summarise the published Phase I and II clinical data for SR90107A/ORG31540 and DX-9065a.

Update in internal medicine.

Also flagged:statinscoronary artery diseasecholesterolIIb/IIIa receptorH. pylori infectiongastroesophageal reflux disease
Journal Article 2000-07-01 ✓ 1 Snippet López-Jiménez F, Brito M, Aude YW, Scheinberg P, Kaplan M, Dixon DA, Schneiderman N, Trejo JF, López-Salazar LH, Ramírez-Barba EJ, Kalil R, Ortiz C, Goyos J, Buenaño A, Kottiech S, Lamas GA.
In-Text Gene Mentions

DCC

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More than 500,000 new medical articles are published every year and available time to keep updated is scarcer every day. Nowadays, the task of selecting useful, consistent, and relevant information for clinicians is a priority in many major medical journals. This review has the aim of gathering the results of the most important findings in clinical medicine in the last few years. It is focused on results from randomized clinical trials and well-designed observational research. Findings were included preferentially if they showed solid results, and we avoided as much as possible including only preliminary data, or results that included only non-clinical outcomes. Some of the most relevant findings reported here include the significant benefit of statins in patients with coronary artery disease even with mean cholesterol level. It also provides a substantial review of the most significant trials assessing the effectiveness of IIb/IIIa receptor blockers. In gastroenterology many advances have been made in the H. pylori eradication, and the finding that the cure of H. pylori infection may be followed by gastroesophageal reflux disease. Some new antivirals have shown encouraging results in patients with chronic hepatitis. In the infectious disease arena, the late breaking trials in anti-retroviral disease are discussed, as well as the new trends regarding antibiotic resistance. This review approaches also the role of leukotriene modifiers in the treatment of asthma and discusses the benefit of using methylprednisolone in patients with adult respiratory distress syndrome, among many other advances in internal medicine.

Also flagged:hereditary hemochromatosisHHpolymeraseironbeta-thalassemia
Journal Article 2000-07-01 ✓ 5 Snippets Ruiz-Argüelles GJ, Garcés-Eisele J, Gelbart T, Monroy-Barreto M, Reyes-Núñez V, Juárez-Morales JL, de Lourdes González-Garrido M, Ramírez-Cisneros FJ, Gallegos-Antúnez D.
In-Text Gene Mentions

Using amplification refractory mutation system polymerase chain reaction, an analysis of HFE-codon 63/282 (H63D/C282Y) gene variants was performed in a group of 153 Mexican mestizo blood donors and six individuals with familial iron overload.

Analysis of HFE-codon 63/282 (H63D/C282Y) gene variants in mexican mestizos. Blood donors and patients with hereditary hemochromatosis.

…Analysis of HFE-codon 63/282 ( H63D/C282Y ) gene variants in mexican mestizos.…

…an analysis of HFE-codon 63/282 ( H63D/C282Y ) gene variants was performed in…

…Analysis ofHFE-codon 63/282 (H63D/C282Y) gen…

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<h4>Background</h4>The prevalence of hereditary hemochromatosis (HH) (H63D/C282Y) gene variants in Mexico is unknown.<h4>Methods</h4>Using amplification refractory mutation system polymerase chain reaction, an analysis of HFE-codon 63/282 (H63D/C282Y) gene variants was performed in a group of 153 Mexican mestizo blood donors and six individuals with familial iron overload.<h4>Results</h4>In normal blood donors, three heterozygotes for the C282Y mutation (2.0%) were found, whereas 18 heterozygotes and one homozygote for the H63D mutation (11.8% and 0.6%, respectively) were identified; there was one compound heterozygote for the C282Y/H63D mutation. These data resulted in allele frequencies of 0.013 (+/-0. 2%, alpha = 0.05) and 0.062 (+/-0.9%, alpha = 0.05), respectively, for these two mutations, results similar to those found in whites. In the six patients with the HH phenotype, two were found to be heterozygous for C282Y and one heterozygous for H63D; three individuals with HH had no gene mutations. Two heterozygous HH individuals were found to have iron overload associated with other conditions: one heterozygous for C282Y infected with HIV, and another heterozygous for H63D with heterozygous beta-thalassemia.<h4>Conclusions</h4>The prevalence of C282Y and H63D HFE gene mutations in Mexican mestizos is similar to that found in other populations. In addition, other gene mutations responsible for HH in the Mexican mestizo population should be investigated, because, in three of six individuals with the HH phenotype, neither of the two mutations was recorded.

Also flagged:hereditary hemochromatosisMHCchromosome
Journal Article 2000-07-01 ✓ 5 Snippets Van Vlierberghe H, Messiaen L, Hautekeete M, De Paepe A, Elewaut A.
In-Text Gene Mentions

hereditary hemochromatosis; it is located 3 Mbp telomeric of the MHC region on chromosome 6p and is called the HFE

…is called theHFEgene.…

…the patients withhemochromatosisharbour the same…

…mutations in Flemishhemochromatosispatients is not…

…clinical diagnosis ofhemochromatosiswere screened for…

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<h4>Unlabelled</h4>Recently Feder et al. have identified the gene responsible for hereditary hemochromatosis; it is located 3 Mbp telomeric of the MHC region on chromosome 6p and is called the HFE gene. The majority of the patients with hemochromatosis harbour the same missense mutation, Cys282Tyr. A second missense mutation (His63Asp) of which the significance is less clear, has also been described. To our knowledge the percentage of these two missense mutations in Flemish hemochromatosis patients is not known.<h4>Materials and methods</h4>Forty nine (49) unrelated patients with the clinical diagnosis of hemochromatosis were screened for the two missense mutations. The missense mutations were diagnosed with a PCR technique.<h4>Results</h4>Of the 49 patients, 46 patients were homozygous for the Cys282Tyr mutation (94%), 2 were heterozygous (4%) and 1 carried two normal alleles (2%). Of the 3 patients not homozygous for the Cys282Tyr mutation, 3 were heterozygous for the His63Asp mutation (2 patients were 'compound heterozygotes').<h4>Discussion</h4>The percentage of homozygotes (Cys282Tyr) in a Flemish hemochromatotic population is comparable with the figures published in the literature. The second missense mutation (His63Asp) could be of importance in association with the Cys282Tyr missense mutation.

Also flagged:anemiacoronary artery diseaseserine proteaseplatelet activationP-selectinglycoprotein Ib
Journal Article 2000-07-01 ✓ 1 Snippet Golański R, Golański J, Chizyński K, Iwaszkiewicz A, Zasłonka J, Pietrucha T, Chrul S, Watała C.
In-Text Gene Mentions

…+ 2, fibrinogen,ATIIIactivity, troponin I…

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<h4>Introduction</h4>Excessive blood loss, as a result of augmented postoperative drainage, is considered one of the most serious cardiosurgical complications. The compounding constitutive anemia seems particularly harmful for patients with coronary artery disease. Aprotinin (Trasylol), a non-specific serine protease inhibitor, is successfully used to reduce excessive postoperative bleeding in such patients. The aim of our study was to verify the hypothesis whether aprotinin used during cardiopulmonary bypass procedure affects hemostatic parameters, which might be crucial for the elevated risk of thromboembolic complications.<h4>Material and methods</h4>The group of 54 patients subjected to coronary artery surgical treatment included 30 patients, who were given intraoperatively 3 million KIU aprotinin each, and 24 subjects non-treated with aprotinin. Aliquots of blood were withdrawn at several time intervals, until the 5th day after the operation. Whole blood platelet activation and reactivity (the expressions of P-selectin and glycoprotein Ib) were monitored by means of flow cytometry. In addition, several plasma parameters, like PAI-1, t-PA, D-dimers, prothrombin fragment F1 + 2, fibrinogen, ATIII activity, troponin I and CK-MB, as well as platelet count were determined at each time point.<h4>Results</h4>In this study we confirmed the essential advantage of the use of aprotinin: both the postoperative blood drainage and the blood units to be transfused postoperatively to cardiosurgical patients were vastly reduced in the aprotinin-treated subjects. The enhanced overall frequency of perioperative myocardial infarction events was not attributed to this group of patients, nor the non Q-wave infarctions were observed more often in patients treated with aprotinin. In these patients, fibrinolysis parameters tended to be depressed (with increased PAI-1 dominating over elevated t-PA) on the first day after the operation, and no significant differences with regard to fibrinogen, prothrombin fragment F1 + 2, troponin I and platelet count. There was a continuous rise in D-dimers in all the postoperative patients, which lasted until the third day and tended to reach plateau at the 5th day after the operation. We failed to reveal the preventive effects of aprotinin on platelet function: both platelet activation and reactivity remained apparently unchanged. Overall, our results rather support the reasoning on the advantageous effects of low doses of aprotinin. The use of this inhibitor reduces the risk of postoperative undesirable bleeding and results in a decreased postoperative drainage and reduced transfused blood units. On the other hand, however, a higher incidence of perioperative Q-wave infarction in the aprotinin-treated patients, although purely apparent and not statistically significant, might question the unlimited safety of the use of aprotinin in cardiovascular operations.

Also flagged:nephrotic syndromeplatelet aggregationfibrinogenantithrombin IIIprotein Spathogenesis
Journal Article 2000-07-01 ✓ 1 Snippet Saxena R, Batra VV, Singh ND.
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…(4.5%) who hadATIIIlevels of 48%.…

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Nephrotic syndrome is a hypercoagulable state with variable prevalence of clinical thrombosis. The role of platelet aggregation, fibrinogen and antithrombin III and protein S levels in the pathogenesis of hypercoagulable state in these patients is controversial. Since no study on Indians is available, the clinical and laboratory profile of 22 patients of nephrotic syndrome (age 18-35 years with an MF ratio of 4:3), have been studied. The coagulation profile revealed a prolonged APTT in 12 patients (54.5%), and a prolonged TT in four (18.1%). In the rest APTT and TT were normal. PT was raised in two patients. Fibrinogen, an acute phase reactant was raised in five patients (22.7%). Antithrombin III levels were reduced in 19 patients (86.4%), normal in one and raised in two patients. Free Protein S levels were high in 12(54.5%), normal in seven and decreased in three patients. Platelet aggregation with adrenaline and adenosine diphosphate was raised in 6 patients. Ultrasonographically detected deep vein thrombosis was seen in one patient only (4.5%) who had ATIII levels of 48%. This low incidence can be explained by elevated protein S levels which was found to be raised in 12(54.5%) cases, protein S being an anticoagulant factor. This low level of clinical thrombosis in Indian patients of nephrotic syndrome may be an ethnic variable factor. It is thus concluded that although patients with nephrotic syndrome have a hypercoagulable state, clinical thrombosis is rarely seen in Indian patients with nephrotic syndrome.

Also flagged:carbohydrateconcanavalin Alectindisulfidebinding
Journal Article 2000-07-01 No Snippets Ramström O, Lehn JM.
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Dynamic combinatorial chemistry (DCC) is a recently introduced approach that is based on the generation of combinatorial libraries by reversible interconversion of the library constituents. In this study, the implementation of such libraries on carbohydrate-lectin interactions was examined. The dynamic carbohydrate libraries were generated from a small set (four or six compounds) of initial carbohydrate dimers through mild disulfide interchange, and selection was performed under two conditions defining either adaptive or pre-equilibrated libraries. Upon initiation, libraries were formed that contained comparable amounts of 10 or 21 individual dimeric species, dynamically interchanging during the scrambling process. They were probed with respect to binding to the plant lectin concanavalin A, either present during library generation or added after equilibration. The libraries could be generated easily both in the presence and absence of the receptor, and a bis-mannose structure was preferentially bound and selected from the mixture. Scrambling of the library in the presence of the receptor resulted in slightly higher yields than when the receptor was added after scrambling, indicating that the receptor to some extent acts as a thermodynamic trap during library generation. The present results illustrate the extention of the DCC approach to carbohydrate recognition groups, the generation of isoenergetic dynamic libraries, and the implementation of either adaptive or pre-equilibrated procedures.

Also flagged:MAO-A5-HT-transporterpanic disorderpanic attacksanticipatory anxietyphobic
Journal Article 2000-07-01 ✓ 3 Snippets Sand P, Lesch KP, Catalano M, Bosi M, Syagailo YV, Okladnova O, Di Bella D, Maffei P, Heils A, Friess F, Politi E, Nöthen MM, Franke P, Stöber G, Fritze J, Maier W, Propping P, Beckmann H, Bellodi L, Riederer P, Deckert J.
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An analysis of possible synergistic effects of the MAO-A gene promoter variant and the short serotonin transporter (5-HTT) gene promoter variant in panic disorder was performed in a German and an Italian sample (combined panic disorder n = 144, combined controls n = 175).

…short serotonin transporter (5-HTT) gene promoter variant…

…modified by the5-HTTgene promoter polymorphism.…

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Recurrent panic attacks, anticipatory anxiety and phobic avoidance characterise panic disorder. The influence of genetic factors on liability to the disease has been the object of several linkage and association studies and appears to relate to an oligo- or polygenic rather than a monogenic mode of inheritance. Recently, an excess of high activity monoamine oxidase A (MAO-A) gene promoter alleles was found in female patients with panic disorder. An analysis of possible synergistic effects of the MAO-A gene promoter variant and the short serotonin transporter (5-HTT) gene promoter variant in panic disorder was performed in a German and an Italian sample (combined panic disorder n = 144, combined controls n = 175). There was no significant difference in odds ratios, suggesting that the observed increase of genetic liability by the long MAO-A gene promoter allele is not modified by the 5-HTT gene promoter polymorphism.

Also flagged:serotonin transporter
Journal Article 2000-07-01 ✓ 2 Snippets Inoue-Murayama M, Niimi Y, Takenaka O, Okada K, Matsuzaki I, Ito S, Murayama Y.
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…of serotonin transporter (5-HTT) gene-linked polymorphic regi…

…allelic variation of5-HTTgene-linked polymorphic region…

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To assess the change of serotonin transporter (5-HTT) gene-linked polymorphic region that has occurred during the process of hominization, we examined the allelic variation of 5-HTT gene-linked polymorphic region (5-HTTLPR) in anthropoid apes such as chimpanzees, gorillas, orang-utans, and gibbons, and determined the DNA sequences of the alleles in each species. All chimpanzees examined shared only the 17.5 repeat allele, while polymorphism was observed in the other apes and the 16 and 20 repeat alleles were most frequent in gorillas and orang-utans, respectively. 5-HTTLPR was highly polymorphic in gibbons and the 17 and 23 repeat alleles were most common among 5 alleles. Alleles with extra-long repeated (22 and 23) sequences were found in orang-utans and gibbons, and the alleles of these Asian apes were similar to the rhesus monkey allele.