Gene Literature Dashboard

The hormone receptor status and proliferative activity characteristics of inflammatory breast cancer (IBC) were studied in a series of 46 patients. ER and PgR were measured by the DCC method and proliferative activity was by the H-3-thymidine autoradiographic labeling index (H-3-Tdr-LI). Tumors were ER and PgR positive in 42% and 38% of cases, respectively, whereas median H-3-Tdr-LI was 3.8%. With regard to clinical aspects, overall survival (OS) was not affected by either ER status (36 cases) or H-3-Tdr-LI value (33 cases). On the contrary, PgR(+) status was able to individualize women with a significantly higher probability of OS (X(2) by long rank test, p=0.03) after 35 months of follow-up. In the subgroup of 14 patients subjected to double biopsy performed before and after administration of primary polychemotherapy, the tumor proliferative activity variations were not related to clinical outcome.

From experiments with purified proteins, it has been concluded that factor XIa (FXIa) is inhibited in plasma mainly by alpha 1-antitrypsin (a1AT), followed by antithrombin III (ATIII), C1-inhibitor (C1Inh), and alpha 2-antiplasmin (a2AP). However, the validity of this concept has never been studied in plasma. We established the relative contribution of different inhibitors to the inactivation of FXIa in human plasma, using enzyme-linked immunosorbent assays (ELISAs) for the quantification of complexes of FXIa with a1AT, C1Inh, a2AP, and ATIII. We found that 47% of FXIa added to plasma formed complexes with C1Inh, 24.5% with a2AP, 23.5% with a1AT, and 5% with ATIII. The distribution of FXIa between these inhibitors in plasma was independent of whether FXIa was added to plasma, or was activated endogenously by kaolin, celite, or glass. However, in the presence of heparin (1 or 50 U/mL), C1Inh appeared to be the major inhibitor of FXIa, followed by ATIII. Furthermore, at lower temperatures, less FXIa-C1Inh and FXIa-a1AT complexes but more FXIa-a2AP complexes were formed. These data demonstrate that the contribution of the different inhibitors to inactivation of FXIa in plasma may vary, but C1Inh is the principal inhibitor under most conditions.

Hepatocellular carcinoma (HCC) is among the 10 most common tumors in the world. However, incidence is not evenly distributed across the world. In many instances, the proximate cause for the tumor can be identified. Chronic hepatitis B infection is probably the most common cause, followed by chronic hepatitis C. Other important causes are alcoholic liver disease, hemochromatosis, alpha 1-antitrypsin deficiency, and other chronic liver diseases. Although proximate causes may be identifiable, pathogenesis remains uncertain. Factors that may be important include the presence of Aflatoxin B1 in food, genetic changes induced by the hepatitis B virus, and repeated rounds of necrosis and regeneration, also induced by hepatitis viruses. The genes involved and the mutations necessary for hepatic carcinogenesis are unknown, with the sole exception of the p53 gene, which is probably a late phenomenon. Screening for HCC is widely practiced despite the lack of evidence of improved survival. The screening tests used include alphafetoprotein levels and ultrasonography. Screening can identify small tumors; however, survival may not be improved, because the presence of cirrhosis may limit the number of patients who can undergo resections; recurrences or second primary tumors are common; and the presence of chronic liver disease means that survival may be limited anyway. There are many different forms of therapy available; unfortunately, most have not been compared in randomized controlled trials. Surgery remains the therapy of choice if feasible. All other therapy is palliative, including chemotherapy, chemoembolization, hepatic artery embolization, various forms of radiotherapy, and various forms of ablative therapy.

Infants and children rarely develop thrombotic complications compared with adults, suggesting that there are protective mechanisms in place for the young. Because endothelial cell surfaces regulate thrombin formation and inhibition, we compared thrombin regulation by human umbilical vein endothelial cell surfaces exposed to defibrinated cord and adult plasmas. After activation by either 10% activated partial thromboplastin reagent (strong activator) or coagulant phospholipids (weak activator) the following were measured: free thrombin, thrombin bound to antithrombin III (ATIII), heparin cofactor II, alpha 2-macroglobulin (alpha 2M), and prothrombin concentration. Free thrombin activity was expressed as remaining activity, after subtraction of thrombin-alpha 2M activity. After 10% activated partial thromboplastin reagent, 100% of prothrombin was consumed and significant amounts of thrombin generated by 2 min. Cord plasma generated significantly less thrombin than adult plasma, reflecting the lower initial plasma concentration of prothrombin. correspondingly, concentrations of thrombin inhibitor complexes were significantly greater in adult plasma than in cord plasma. After coagulant phospholipids, 50% of prothrombin was consumed and negligible thrombin activity measured for both adult and cord plasma. Similar amounts of thrombin inhibitor complexes were formed. ATIII was the predominant inhibitor of thrombin in adult plasma, whereas alpha 2M was as important as ATIII in cord plasma for both activators. When cord plasma concentrations of ATIII were increased to adult values, the proportion complexed to alpha 2M decreased. We conclude that on human umbilical vein endothelial cells, the capacity to generate thrombin is decreased in adult and cord plasmas.(ABSTRACT TRUNCATED AT 250 WORDS)

A recent report from this laboratory described an in vitro system in which CD34+ cells are stimulated to form mature megakaryocytes and, subsequently, cytoplasmic processes also known as pro-platelets that give rise to functional platelets. Thrombin, an important regulator of hemostasis, has been demonstrated to have an inhibitory role in cytoplasmic process formation from both human and guinea pig megakaryocytes. This inhibition can be reversed by antithrombin III (ATIII), an inhibitor of thrombin, in combination with heparin, a cofactor of ATIII and a glycosaminoglycan. Using the described human in vitro system, the role of thrombin and of glycosaminoglycans are investigated. Thrombin receptors are expressed on megakaryocytes, suggesting that the inhibition by thrombin may be direct. Matrigel, a basement membrane matrix containing glycosaminoglycans, is used to compare the frequency and the rate of cytoplasmic process formation. A possible role of glycosaminoglycans in platelet production is discussed.

<h4>Background/aims</h4>Iron cytotoxicity may play an important role in chronic hepatitis C. The effects of venesection suggest that a slight iron overload contributes to hepatic injury in subjects infected with hepatitis C virus. A better indication of the efficacy of venesection was studied in patients with and without overt iron overloading.<h4>Methods</h4>All 40 patients had chronic hepatitis C but none had hemochromatosis of a known etiology. A serum ferritin level of 10 ng/ml or less was chosen as the treatment goal. A mean blood volume of 2400 +/- 1100 ml was removed during treatments lasting 5 +/- 3 months.<h4>Results</h4>Treatment significantly reduced the mean serum levels of alanine aminotransferase activity from 128 +/- 74 to 63 +/- 28 IU/l (p < 0.01). The baseline enzyme activity was highly correlated with reduction in activity after treatment (r = 0.94, p < 0.01), but the baseline levels of ferritin and histochemistry for iron showed poor correlations with the reduction in enzyme activity (r = 0.63 with p < 0.01 and r = 0.38 with p < 0.05, respectively).<h4>Conclusions</h4>Thus, serum levels of aminotransferases were a more important indicator for venesection than conventional indices of iron overload, probably because cytotoxic iron includes some reactive iron species rather than stored iron alone.

Although various hematological disorders have been considered to be etiologic factors in deep vein thrombosis (DVT), the involvement of dysplasminogenemia (DPG) in DVT has not been studied in detail. In 72 consecutive DVT patients, the presence of DVT was suspected based on a history of lower limb swelling and tenderness with acute onset, and was confirmed by duplex scanning, radioisotope venography, or contrast venography. DPG was identified by the observation of dissociation between the activity and antigenicity of plasminogen. Of the 72 patients, 9 (12.5%) were diagnosed as having DPG, and several antithrombin-III deficiency and protein C and S deficiency were identified. The mean age of the genetically normal and DPG patients was 52 +/- 15 and 40 +/- 15 years, respectively (p < 0.05). Thus, these findings suggest that DPG is deeply related to the development of DVT, and that abnormality of the fibrinolytic system is one of the major etiologic factors in DVT.

Junin virus, an arenaviridae, is the etiological agent of Argentine hemorrhagic fever. In addition to thrombocytopenia, patients present several alterations in both the blood coagulation and the fibrinolytic system, but diffuse intravascular coagulation could not be demonstrated. To investigate further the activation status of the two systems, levels of thrombin-antithrombin complexes (TAT), prothrombin fragment 1 + 2, protein C, total and free protein S, C4bBP, antithrombin III, t-PA, PAI-1 and D-dimer were measured. Fourteen patients with a confirmed diagnosis of Argentine hemorrhagic fever were included in the study, 2 were severe, 3 moderate and 9 mild clinical cases, but hemorrhages were slight throughout. Blood samples were collected for 6 consecutive days on admission and on remission. At admission TAT and F1 + 2 levels were increased in 13/14 patients, reaching 0.33 nM (0.06-0.87) and 2.16 nM (0.96-6.5), respectively. PC was low in 4 cases, fPS in 6 and tPS in 2, whereas C4bBP and ATIII values were within normal range. t-PA and D-dimer levels were high in 11/14 patients, reaching 20 ng/ml (2.7-106) and 1660 ng/ml (877-3780) respectively, while PAI-1 was considerably increased in the 2 severe cases and normal in the remainder. These results suggest low level though persistent process of blood coagulation and fibrinolysis activation in this viral hemorrhagic disease. We believe these abnormalities may lead to the well described bleeding manifestations in these patients.

A new method of chemically immobilizing antibody on nylon was developed. The method consists of serial treatments with HCl, polyethylene imine, and maleic anhydride methylvinyl ether copolymer, which resulted in the stable immobilization of sufficient amounts of antibodies on nylon. This principle was used to differentially detect two immunologically related but nonidentical hemolysins (thermostable direct hemolysin [TDH] and TDH-related hemolysin [TRH]) of Vibrio parahaemolyticus in a modified enzyme-linked immunosorbent assay with antibodies immobilized on nylon slips (NSIT). The results (dark purple color on nylon slips) were easily evaluated by the naked eye. The results with NSIT were compatible with those obtained by using DNA probes or a conventional bacterial culture test, not only with cultured specimens but also with clinical specimens (diarrheal stool samples). Furthermore, the NSIT differentially detected TDH and TRH in a single test. The antibody immobilization method developed here is applicable to various immunological detection methods and may improve their sensitivity and specificity.

Using retinoic acid receptor (RAR) reporter cells specific for either RAR alpha, beta or gamma, we have identified synthetic retinoids which specifically induce transactivation by RAR beta, while antagonizing RA-induced transactivation by RAR alpha and RAR gamma. Like RA, these synthetic retinoids allow all three RAR types to repress AP1 (c-Jun/c-Fos) activity, demonstrating that the transactivation and transrepression functions of RARs can be dissociated by properly designed ligands. Using AP1 reporter cells, we also show that glucocorticoids or vitamin D3, together with either RA or these 'dissociating' synthetic retinoids, can synergistically repress phorbol ester-induced AP1 activity. RA, but not these 'dissociating' retinoids, induced transcription of an interleukin-6 promoter-based reporter gene transiently transfected into HeLa cells together with RARs. Using Ki-ras-transformed 3T3 cells as a model system, we show that both RA and the 'dissociating' retinoids inhibit anchorage-independent cell proliferation, suggesting that retinoid-induced growth inhibition may be related to AP1 transrepression.

Allelic alterations of chromosome 18 microsatellites were determined using normal and tumor DNA pairs from 29 patients with infiltrating ductal carcinoma of the breast. Loss of heterozygosity was detected in 62% (18 of 29 patients) of the tumors at one or more of these microsatellites. Eight of the 18 patients exhibited deletions in the region at 18q21.1. This chromosomal band is known to contain a tumor suppressor gene (DCC) whose expression is frequently inactivated in several types of cancer. Ten other patients had deletions in regions not included in the DCC locus. Five of these patients revealed a common deletion at the D18S50 locus (18q23), and the other five patients had deletions in various other regions of the chromosome. No apparent correlation between loss of heterozygosity of chromosome 18 microsatellites and the clinical stage was found in this series. The results indicate that, in addition to the DCC locus, the 18q23 region is likely to contain a second tumor suppressor gene relevant to breast carcinogenesis. Four percent of all microsatellites tested in these patients showed allelic differences in the sizes of repeat units between tumor and the corresponding constitutional DNAs. The pattern of allele instability observed in breast carcinoma differed from that originally reported in a hereditary type of colorectal carcinoma. The observation suggests that this phenomenon is not a mechanism specific to neoplastic processes in breast carcinoma.

The interaction of the endogenous vasoconstrictors endothelin (ET), angiotensin II (Ang II) and catecholamines with the kallikrein-kinin-, prostaglandin and renin-aldosterone systems in the pathogenesis of acute renal failure (ARF) is still to be defined. In 18 anesthesized pigs the influence of i.v. bolus applications of ET (2 micrograms/kg), Ang II (10 micrograms/kg) and norepinephrine (NE; 20 micrograms/kg) on hemodynamics, plasmatic coagulation and fibrinolysis system, prostaglandins and renal function was studied. ET induced a biphasic change in blood pressure, starting with an initial short-lasting reduction followed by a long-lasting elevation of systolic and diastolic blood pressure. Endothelin bolus resulted in a significant increase of 6-keto-PGF1 alpha, PGE2 and TXB2 plasma levels (P < 0.05 against preinjection values), whereas prostaglandins remained unchanged in the Ang II and NE groups. There was a distinct correlation between the plasma ET and 6-keto-PGF1 alpha levels (r = 0.82). In contrast to Ang II or NE, ET induced a shortening of the activated partial thromboplastin time (aPTT) and increase of antithrombin III levels (ATIII), fibrin monomers (FM), prekallikrein (PKK) and factor VIII activity at the beginning. Finally a pronounced decrease of ATIII, FM and PKK occurred, indicating a consumptive coagulopathy. At the end of the experiment, elevated plasma renin activity and pCO2, significantly decreased creatinine clearance, blood pH, pO2, base excess, HCO3-, oxygen saturation (P < 0.01), a distinct glomerular proteinuria, and a final anuria were observated. These results reveal that ET activates the plasmatic coagulation system and induces an ARF accompanied by impairment of pulmonary function.(ABSTRACT TRUNCATED AT 250 WORDS)

We compared concentrations of cytosolic estrogen receptors (ERc) measured in 35 postmenopausal endometrial carcinomas by ligand binding method (LBA) (dextran-coated charcoal assay) and enzyme immunoassay (EIA). Correlations between ERc, nuclear estrogen receptors (ERn) determined by EIA, and cytosolic progesterone receptors (PR) measured by LBA were also studied. While ERc concentrations determined by LBA and EIA were highly correlated (r: 0.94), ERc values detected by LBA were approximately twice those found by EIA (median values of ERc: 155 vs. 64 fmol/mg cytosol protein, DCC vs. EIA). The percentages of ERc positive tumors were 89% by LBA and 77% by EIA. The median fraction of total ER present as ERn was 63%. PR levels correlated positively with ERn concentrations (r: 0.73). We explore possible reasons why greater concentrations of ERc are determined by estradiol binding than by the ER-EIA kit in endometrial cancer.

A Drosophila Promoter Database containing 252 independent Drosophila melanogaster promoter entries has been compiled. The database and its subsets have been searched for overrepresented sequences. The analysis reveals that the proximal promoter region displays the most dramatic nucleotide sequence irregularities and exhibits a tripartite structure, consisting of TATA at -25/-30 bp, initiator (Inr) at +/- 5 bp and a novel class of downstream elements at +20/+30 bp from the RNA start site. These latter elements are also strand-specific. However, they differ from TATA and Inr in several aspects: (1) they are represented not by a single, but by multiple sequences, (2) they are shorter, (3) their position is less strictly fixed with respect to the RNA start site, (4) they emerge as a characteristic feature of Drosophila promoters and (5) some of them are strongly overrepresented in the TATA-less, but not TATA-containing, subset. About one-half of known Drosophila promoters can be classified as TATA-less. The overall sequence organization of the promoter region is characterized by an extended region with an increase in GC-content and a decrease in A, which contains a number of binding sites for Drosophila transcription factors.

<h4>Background</h4>The observation that human meningiomas are rich in steroid hormone receptors has led to the hypothesis that their growth may be hormonally dependent. This study aims to correlate the biochemical expression of estrogen (ER) and progesterone receptors (PgR) with their nuclear immunoreactivity in a large series of meningiomas.<h4>Methods</h4>The occurrence of ER and PgR in patients with primary untreated meningiomas was studied with a dextrancoated charcoal method (DCC) and the results were compared with those of an immunocytochemical assay (ICA). Progesterone and estrogen receptor determinations were performed on 103 and 99 meningiomas respectively using the DCC assay. Forty-six and 44 of these samples were immunocytochemically evaluated for the presence of PgR and ER respectively.<h4>Results</h4>Of the 46 samples evaluated by both the methods, 89% were found PgR positive by DCC and 70% by ICA. The overall concordance between PgR-DCC and PgR-ICA was 80%. Whereas low concentrations of ER were found in 8/44 samples (18%) assayed by DCC, specific staining was never observed in any of the samples tested by ICA.<h4>Conclusions</h4>Our findings confirm that the majority of meningiomas are devoid of ER and that the biochemical evidence of PgR correlates well with the nuclear localization of progesterone receptors determined by immunocytochemistry.

The neurodegenerative disorder Huntington disease (HD) appears to be caused by an increase in the number of repeats of the trinucleotide CAG located near the 5' end of the gene. The nucleotide sequences of the cDNA and the gene predict that the HD protein has a molecular weight of 347,000 (3144 amino acids) and that the CAG repeats encode a segment of polyglutamine beginning 17 amino acids from the amino terminus. Because the CAG repeat plays such a critical role in the etiology of the disease, we sought to obtain evidence that the polyglutamine segment is indeed present in the protein. We used two peptides, hd1-peptide (FESLKSFQQ), predicted to lie at amino acid positions 11-19, just amino-terminal to the polyglutamine segment, and hd2-peptide (QQPRNKPLK), predicted to lie at amino acid positions 2531-2539, to induce polyclonal antibodies in NZW rabbits. Both antibodies recognize a protein on Western blots of about 350 kDa in cell lysates from human brain tissue and human and monkey cell lines, including cells from individuals heterozygous and homozygous for the disease. These results suggest that the HD protein in these cells contains the predicted amino terminal segment, and by inference, the segment of polyglutamine, and that the protein is expressed even when only mutant copies of the gene are present. Interestingly, the antibody to hd1-peptide does not recognize the HD protein on Western blots containing lysates from rodent cell lines, whereas the antibody to hd2-peptide does. This discrimination provides a useful means to assay for the presence of the human HD protein in a rodent cell background.

Minor histocompatibility (H) Ags, encoded by autosomal and sex-linked genes, have classically been identified by the cytolytic T lymphocyte response to class I-bound minor H Ags. A limited number of studies have identified minor H Ags (defined by congenic strains) that stimulate Th cells. We have selected a panel of minor H Ag-specific, CD4+ Th hybrids by the fusion of a BW5147 variant with a C57BL/6 anti-BALB.B T cell line. Studied hybrids secrete IL-2 following stimulation with BALB.B spleen cells and stimulation is blocked with anti-I-Ab Ab. These Th hybrids recognize a minimum of six different Ags (helper T target (HTT)) encoded by independently segregating genes as defined by stimulator cells from 11 CXB recombinant inbred strains. The CXB strain distribution patterns of detected Ags did not match the distribution pattern of the BALB/c MTV6 viral genome indicating that none of the detected Ags were known viral superantigens. Four tested HTT Ags appeared not to be acquired by stimulators as exogenous Ags as BALB.B spleen cells but not a mixture of BALB/c spleen cells and C57BL/6 APC stimulated IL-2 production by the respective Th hybrids. To determine whether Th hybrids recognized peptides bound to I-Ab, I-Ab molecules were immunoprecipitated from the LB27.4 cell line that stimulated the A6.5.5 hybrid (HTT-4 specific). Peptides were extracted from I-Ab molecules, ultrafiltered, and separated by HPLC. A single fraction (with flanking peaks of lower activity) sensitized syngeneic APC to stimulate A6.5.5 hybrid cells; sensitization was observed at pH 5.0 but not pH 7.0, consistent with HTT-4 peptide:I-Ab binding occurring in an endosomal compartment. These observations indicate that at least one class II-restricted minor H Ag is recognized by Th cells as a peptide bound to class II molecules.

Antisense oligonucleotides targeting p53 have been hailed as a potentially new technique for treating patients with cancer, and there have been encouraging reports of good patient tolerance in vivo and of antiproliferative effects in vitro. However, evidence is lacking that these oligonucleotides are acting via an antisense interaction to modulate p53 expression. We examined a phosphorothioate antisense oligonucleotide, directed against exon 10 of the TP53 gene, and a chimaeric phosphorothioate-phosphodiester oligonucleotide directed against the p53 translation initiation codon. Both failed to specifically suppress p53 protein production in a cell-free assay system or to have any effect on mutant p53 expression by human pancreatic cancer cell lines. Antiproliferative effects were apparent, especially with the phosphorothioate antisense oligonucleotide, but this was independent of the p53 status of the cells (mutant, wild-type or absent) and also occurred with the control (sense and randomised) oligonucleotides. The most dramatic antiproliferative effects were seen with the 'control' phosphorothioate oligonucleotides. These findings suggest that the antiproliferative effects of some antisense oligonucleotides may be unrelated to expression of the gene they have been designed to target.

To investigate possible relationships between genetic alterations and hormonal deregulation during breast cancer development and/or progression, we examined 616 primary breast cancers for loss of heterozygosity (LOH) at chromosomal regions 16q24, 17p13.3 and 17q21, and for amplifications of the ERBB2 and c-MYC loci. A comparison of oestrogen receptor (ER) and progesterone receptor (PgR) status in tumour cells with data concerning these genetic alterations revealed that LOH at 17q21 was significantly correlated with absence of oestrogen receptors (ER) (P < 0.0003) or progesterone receptors (PgR) (P < 0.0001), and with the absence of both (P < 0.0001). Similarly, a significant association was observed between amplification of ERBB2 and the absence of either ER or PgR. LOH at 17p13.3 was associated with the absence of PgR (P < 0.01). These data suggest a possible relationship between specific genetic changes on chromosome 17 and hormonal deregulation in the progression of breast cancer.

In order to identify the possible role of the DCC gene in neoplasms of the human female reproductive tract, messenger RNA expression of the DCC gene was examined by reverse transcriptase-polymerase chain reaction, and expression of the DCC gene product was detected immunohistochemically. While histologically normal endometrium, cervical epithelium and ovary expressed detectable mRNA of the DCC gene, three of eight (37%) endometrial carcinomas, one of two (50%) cervical carcinomas and 9 of 22 (41%) ovarian malignant tumours had significantly reduced or negligible DCC expression, and another endometrial carcinoma and two other ovarian tumors underexpressed DCC when compared with histologically normal endometrial or ovarian tissues. Impaired DCC mRNA expression was detected more frequently in grade 3 ovarian epithelial tumours than in grade 1 tumours (P = 0.002). Loss of expression of the DCC gene product detected by immunohistochemistry significantly correlated with the loss of mRNA expression in ovarian carcinomas (P = 0.01 by chi-square test) or in both endometrial and ovarian carcinomas combined (P = 0.001). Loss of heterozygosity of the DCC gene was also evaluated by restriction fragment polymorphism analysis of the polymerase chain reaction-amplified DNA fragment. Loss of heterozygosity of the DCC gene was detected in one of seven (14%) informative cases of endometrial carcinomas, 1 of 11 (9%) informative cases of cervical carcinomas and two of six (33%) informative cases of ovarian tumours. These results demonstrate that inactivation of the DCC gene, especially by the loss of expression, plays a significant role in the aetiology of neoplasms of the human reproductive tract.

The gene for Batten disease (juvenile-onset neuronal ceroid lipofuscinosis, or Spielmeyer-Sjögren disease), CLN3, maps to 16p11.2-12.1. Four microsatellite markers--D16S288, D16S299, D16S298, and SPN--are in strong linkage disequilibrium with CLN3 in 142 families from 16 different countries. These markers span a candidate region of approximately 2.1 cM. CLN3 is most prevalent in northern European populations and is especially enriched in the isolated Finnish population, with an incidence of 1:21,000. Linkage disequilibrium mapping was applied to further refine the localization of CLN3 in 27 Finnish families by using linkage disequilibrium data and information about the population history of Finland to estimate the distance of the closest markers from CLN3. CLN3 is predicted to lie 8.8 kb (range 6.3-13.8 kb) from D16S298 and 165.4 kb (132.4-218.1 kb) from D16S299. Enrichment of allele "6" at D16S298 (on 96% of Finnish and 92% of European CLN3 chromosomes) provides strong evidence that the same major mutation is responsible for Batten disease in Finland as in most other European countries and that it is therefore not a Finnish mutation. Genealogical studies show that Batten disease is widespread throughout the densely populated regions of Finland. The ancestors of two Finnish patients carrying rare alleles "3" and "5" at D16S298 in heterozygous form originate from the southwestern coast of Finland, and these probably represent other foreign mutations. Analysis of the number and distribution of CLN3 haplotypes from 12 European countries provides evidence that more than one mutation has arisen in Europe.

A novel class of conserved transcription factors has been identified from the molecular cloning of AF10, the gene involved in the t(10;11)(p12;q23) translocation of acute myeloid leukemias. AF10 encodes a 109-kD protein of 1,027 amino acids and contains an N-terminal zinc finger region and a C-terminal leucine zipper. These structures have been found to be conserved in sequence and position in three other proteins, AF17, BR140, and a previously unrecognized Caenorhabditis elegans gene, provisionally named CEZF. The overall structure, level of sequence conservation, and expression pattern suggest that these genes encode a new class of transcription factors, some of which are targets for chromosomal translocation in acute leukemia.

The inhibition mechanism of a polysaccharide anticoagulant, depolymerized holothurian glycosaminoglycan (DHG), was examined by analyzing its effects on the clotting time of human plasma depleted of antithrombin III (ATIII), of heparin cofactor II (HCII), or of both heparin cofactors. The effect exerted by this agent on the activation of prothrombin and factor X in purified human components were also examined and all effects were compared with those of other glycosaminoglycans (GAGs). The capacity of DHG to prolong activated partial thromboplastin time was not reduced in ATIII-depleted, HCII-depleted, HCII-depleted, or ATIII- and HCII-depleted plasma, whereas its capacity to prolong prothrombin time and thrombin clotting time was reduced in HCII-depleted plasma. DHG inhibited the amidolytic activity of thrombin in the presence of HCII with a second order rate constant of 1.2 x 10(8) (mol/L)-1 min-1. These results indicated that DHG has two different inhibitory activities, one being an HCII-dependent thrombin inhibition and the other an ATIII- and HCII-independent inhibition of the coagulation cascade. The heparin cofactors-independent inhibitory activity of DHG was investigated in the activation of prothrombin by factor Xa and in the activation of factor X by tissue factor-factor VIIa complex or by factor IXa. DHG significantly inhibited the activation of factor X by factor IXa in the presence of factor VIIIa, but not in the absence of factor VIIIa. The interaction between DHG and factors IXa, VIIIa, and X was investigated with a DHG-cellulofine column, on which DHG had strong affinity for factors IXa and VIIIa. These findings show that the heparin cofactors-independent inhibition exhibited by DHG was caused by inhibition of the interaction of factor X with the intrinsic factor Xase complex, probably by binding to the factor IXa-factor VIIIa complex.