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Variations in the amount of different RNA species were investigated during in vitro maturation of bovine oocytes. Total RNA content was estimated to be 2 ng before meiosis, and after meiosis resumption, no decrease was observed. Ribosomal RNA did not appear to be degraded either, whereas poly(A) RNA was reduced by half after meiosis resumption, from 53 pg to 25 pg per oocyte. Real-time polymerase chain reaction was performed on growth and differentiation factor-9 (GDF-9), on cyclin B1, and on two genes implicated in the resistance to oxidative stress, glucose-6-phosphate-dehydrogenase (G6PD) and peroxiredoxin-6 (PRDX6). When these transcripts were reverse-transcribed with hexamers, the amplification results were not different before or after in vitro maturation. But when reverse transcription was performed with oligo(dT), amplification was dramatically reduced after maturation, except for cyclin B1 mRNA, implying deadenylation without degradation of three transcripts. Although calf oocytes have a lower developmental competence, their poly(A) RNA contents were not different from that of cow oocytes, nor were they differently affected during maturation. When bovine oocytes were maintained in vitro under meiotic arrest with CDK inhibitors, their poly(A) RNA amount increased, but this rise did not change the poly(A) RNA level once maturation was achieved. The increase could not be observed under transcription inhibition and, when impeding transcription and adenylation, the poly(A) RNA decreased to a level normally observed after maturation, in spite of the maintenance of meiotic arrest. These results demonstrate the importance of adenylation and deadenylation processes during in vitro maturation of bovine oocytes.

Transferrin receptor (TfR) is a dimeric cell surface protein that binds both the serum iron transport protein transferrin (Fe-Tf) and HFE, the protein mutated in patients with the iron overload disorder hereditary hemochromatosis. HFE and Fe-Tf can bind simultaneously to TfR to form a ternary complex, but HFE binding to TfR lowers the apparent affinity of the Fe-Tf/TfR interaction. This apparent affinity reduction could result from direct competition between HFE and Fe-Tf for their overlapping binding sites on each TfR polypeptide chain, from negative cooperativity, or from a combination of both. To explore the mechanism of the affinity reduction, we constructed a heterodimeric TfR that contains mutations such that one TfR chain binds only HFE and the other binds only Fe-Tf. Binding studies using a heterodimeric form of soluble TfR demonstrate that TfR does not exhibit cooperativity in heterotropic ligand binding, suggesting that some or all of the effects of HFE on iron homeostasis result from competition with Fe-Tf for TfR binding. Experiments using transfected cell lines demonstrate a physiological role for this competition in altering HFE trafficking patterns.

We have used statistical models based on Fourier transform-infrared spectra to differentiate between the DNA structure of normal granulocytes and those obtained from patients with myelodysplastic syndrome (MDS). The substantial degree of discrimination achieved between the two DNA groups is attributed to differences in the nucleotide base and backbone structures. These structural differences allowed for the development of a discriminant analysis model that predicted, with high sensitivity and specificity, which DNA came from normal granulocytes vs. granulocytes from MDS patients. The findings are a promising basis for developing a blood test to diagnose and predict the occurrence of MDS, for which there is currently a paucity of molecular markers.

Calcineurin is a highly conserved regulator of Ca(2+) signaling in eukaryotes. In fission yeast, calcineurin is not essential for viability but is required for cytokinesis and Cl(-) homeostasis. In a genetic screen for mutations that are synthetically lethal with calcineurin deletion, we isolated a mutant, cis1-1/apm1-1, an allele of the apm1(+) gene that encodes a homolog of the mammalian micro1A subunit of the clathrin-associated adaptor protein-1 (AP-1) complex. The cis1-1/apm1-1 mutant as well as the apm1-deleted (Deltaapm1) cells showed distinct phenotypes: temperature sensitivity; tacrolimus (FK506) sensitivity; and pleiotropic defects in cytokinesis, cell integrity, and vacuole fusion. Electron micrographs revealed that Deltaapm1 cells showed large vesicular structures associated with Golgi stacks and accumulated post-Golgi secretory vesicles. Deltaapm1 cells also showed the massive accumulation of the exocytic v-SNARE Syb1 in the Golgi/endosomes and a reduced secretion of acid phosphatase. These phenotypes observed in apm1 mutations were accentuated upon temperature up-shift and FK506 treatment. Notably, Apm1-GFP localized to the Golgi/endosomes, the spindle pole bodies, and the medial region. These findings suggest a role for Apm1 associated with the Golgi/endosome function, thereby affecting various cellular processes, including secretion, cytokinesis, vacuole fusion, and cell integrity and also suggest that calcineurin is involved in these events.

BACKGROUND: We have developed magnetite cationic liposomes (MCLs) and applied them to local hyperthermia as a mediator. MCLs have a positive charge and generate heat under an alternating magnetic field (AMF) by hysteresis loss. In this study, the effect of hyperthermia using MCLs was examined in an in vivo study of hamster osteosarcoma. METHOD: MCLs were injected into the osteosarcoma and then subjected to an AMF. RESULTS: The tumor was heated at over 42 degrees C, but other normal tissues were not heated as much. Complete regression was observed in 100% of the treated group hamsters, whereas no regression was observed in the control group hamsters. At day 12, the average tumor volume of the treated hamsters was about 1/1000 of that of the control hamsters. In the treated hamsters, no regrowth of osteosarcomas was observed over a period of 3 months after the complete regression. CONCLUSION: These results suggest that this treatment is effective for osteosarcoma.

Iron is essential for life in almost all organisms and, in mammals, is absorbed through the villus cells of the duodenum. Using a human colonic carcinoma cell line that has many duodenal characteristics, HT29, we show that genes involved in intestinal iron transport are endogenously expressed. When stably transfected to express the hereditary hemochromatosis protein HFE these cells have increased ferritin levels. We demonstrate that this is not due to an effect on the transferrin (TF)-mediated iron uptake pathway but rather due to inhibition of iron efflux from the cell. The effect of HFE was independent of its interaction with TF receptor 1 as indicated by similar results using both the wild type HFE and the W81A mutant that binds TF receptor 1 with greatly reduced affinity. HFE expression did not affect the mRNA levels of most of the genes involved in iron absorption that were tested; however, it did correspond to a decrease in hephaestin message levels. These results point to a role for HFE in inhibition of iron efflux in HT29 cells. This is a distinct role from that in HeLa and human embryonic kidney 293 cells where HFE has been shown to inhibit TF-mediated iron uptake resulting in decreased ferritin levels. Such a distinction suggests a multifunctional role for HFE that is dependent upon expression levels of proteins involved in iron transport.

<h4>Background</h4>Huntington's disease (HD) is a fully penetrant, autosomal dominantly inherited disorder associated with abnormal expansions of a stretch of perfect CAG repeats in the 5' part of the IT15 gene. The number of repeat units is highly predictive for the age at onset (AO) of the disorder. But AO is only modestly correlated with repeat length when intermediate HD expansions are considered. Circumstantial evidence suggests that additional features of the HD course are based on genetic traits. Therefore, it may be possible to investigate the genetic background of HD, i.e. to map the loci underlying the development and progression of the disease. Recently an association of Glutathione S-Transferase Omega 1 (GSTO1) and possibly of GSTO2 with AO was demonstrated for, both, Alzheimer's (AD) and Parkinson's disease (PD).<h4>Methods</h4>We have genotyped the polymorphisms rs4925 GSTO1 and rs2297235 GSTO2 in 232 patients with HD and 228 controls.<h4>Results</h4>After genotyping GSTO1 and GSTO2 polymorphisms, firstly there was no statistically significant difference in AO for HD patients, as well as secondly for HD patients vs. controls concerning, both, genotype and allele frequencies, respectively.<h4>Conclusion</h4>The GSTO1 and GSTO2 genes flanked by the investigated polymorphisms are not comprised in a primary candidate region influencing AO in HD.

The aim of the study was to assess the frequencies of the hereditary hemochromatosis HFE mutations C282Y, H63D, and S65C in the population in the Faroe Islands. The series comprised 200 randomly selected blood donors of Faroese heritage. The frequency of the C282Y, H63D, and S65C mutations on the HFE gene was assessed by genotyping using the polymerase chain reaction (PCR) technique and calculated from direct allele counting. We found no C282Y homozygous subjects; 28 (14.0%) subjects were C282Y heterozygous and four subjects were C282Y/H63D compound heterozygous (2.0%). The C282Y allele frequency was 8.0% (95% CI 5.3-10.7%). The series contained three (1.5%) H63D homozygous subjects and 60 (30.0%) H63D heterozygous subjects. The H63D allele frequency was 17.5% (95% CI 13.8-21.2%). There were four (2.0%) S65C heterozygous subjects. The S65C allele frequency was 1.0% (95% CI 0.3-2.5%). The frequency of the C282Y mutation is high in Faroese blood donors, being close to and not significantly different from the frequencies reported in other Scandinavian countries: Denmark 5.7%, Norway 6.6%, Iceland 5.1%, and Sweden 6.1%. The frequency of the H63D mutation in Faroese subjects is significantly higher than the frequency in Denmark 12.8% (p=0.007), Iceland 10.9% (p=0.003), and Sweden 12.4% (p=0.015), but not from the frequency in Norway 11.2% (p=0.063). The frequency of the S65C mutation in Faroese subjects is not significantly different from the frequencies in Denmark 1.5% and Sweden 1.6%. Screening of larger groups of the Faroese population for HFE mutations especially C282Y should be considered in order to establish the penetrance.

BACKGROUND: Congenital thrombotic risk factors, oncological diseases and its therapies have been related to an increased occurrence of upper extremities deep venous thrombosis (UEDVT). PATIENTS AND METHODS: We studied seven patients bearing lymphoma (one Hodgkin's and six non-Hodgkin's) who developed UEDVT, one at diagnosis and six during chemotherapy (two of these six cases had implantation of a central venous catheter and four received Growth Colony Stimulating Factors in addition to chemotherapy). Patients were screened for: factor V G1691A (Leiden), prothrombin G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T mutations and antithrombin III, proteins C and S plasma activity. RESULTS: All patients were wild-type homozygotes for G20210A. One was heterozygote for factor V G1691A, the other 6 were wild-type homozygotes. Three of the 7 patients were homozygotes and 2 heterozygotes for the MTHFR mutation; the remaining 2 were wild-type homozygotes. Clotting inhibitor levels were normal in all patients. CONCLUSIONS: UEDVT in patients bearing haematological malignancies can occur irrespective of congenital thrombophilic alterations. However, in a subgroup of patients UEDVT could also depend on congenital thrombophilic alterations. A screening for inherited thrombophilia can identify high risk patients that could be specifically treated to prevent thrombotic complications.

<h4>Background</h4>Calcium phosphate manufactured samples, prepared with hydroxyapatite, are used as either spacers or fillers in orthopedic surgery, but these implants have never been used under conditions of mechanical stress. Similar conditions also apply with cements. Many authors have postulated that cements are a useful substitute material when implanted in vivo. The aim of this research is to develop a low cristalline material similar to bone in porosity and cristallinity.<h4>Methods</h4>Commercial hydroxyapatite (HAp) and monetite (M) powders are mixed with water and compacted to produce cylindrical samples. The material is processed at a temperature of 37-120 degrees C in saturated steam to obtain samples that are osteoconductive. The samples are studied by X-ray powder diffraction (XRD), Vickers hardness test (HV), scanning electron microscopy (SEM), and porosity evaluation.<h4>Results</h4>The X-ray diffractions of powders from the samples show patterns typical of HAp and M powders. After thermal treatment, no new crystal phase is formed and no increase of the relative intensity of the peaks is obtained. Vicker hardness data do not show any relationship with treatment temperature. The total porosity decreases by 50-60% according to the specific thermal treatment. Scanning electron microscopy of the surfaces of the samples with either HAp 80%-M 20% (c) or Hap 50%-M 50% (f), show cohesion of the powder grains.<h4>Conclusions</h4>The dissolution-reprecipitation process is more intesive in manufactured samples (c) and (f), according to Vickers hardness data. The process occurs in a steam saturated environment between 37 degrees and 120 degrees C. (c) (f) manufactured samples show pore dimension distributions useful to cellular repopulation in living tissues.

We generated mice harboring a single amino acid mutation in the motor domain of nonmuscle myosin heavy chain II-B (NMHC II-B). Homozygous mutant mice had an abnormal gait and difficulties in maintaining balance. Consistent with their motor defects, the mutant mice displayed an abnormal pattern of cerebellar foliation. Analysis of the brains of homozygous mutant mice showed significant defects in neuronal migration involving granule cells in the cerebellum, the facial neurons, and the anterior extramural precerebellar migratory stream, including the pontine neurons. A high level of NMHC II-B expression in these neurons suggests an important role for this particular isoform during neuronal migration in the developing brain. Increased phosphorylation of the myosin II regulatory light chain in migrating, compared with stationary pontine neurons, supports an active role for myosin II in regulating their migration. These studies demonstrate that NMHC II-B is particularly important for normal migration of distinct groups of neurons during mouse brain development.

It has been shown that beta auxiliary subunits increase current amplitude in voltage-dependent calcium channels. In this study, however, we found a novel inhibitory effect of beta3 subunit on macroscopic Ba(2+) currents through recombinant N- and R-type calcium channels expressed in Xenopus oocytes. Overexpressed beta3 (12.5 ng/cell cRNA) significantly suppressed N- and R-type, but not L-type, calcium channel currents at "physiological" holding potentials (HPs) of -60 and -80 mV. At a HP of -80 mV, coinjection of various concentrations (0-12.5 ng) of the beta3 with Ca(v)2.2alpha(1) and alpha(2)delta enhanced the maximum conductance of expressed channels at lower beta3 concentrations but at higher concentrations (>2.5 ng/cell) caused a marked inhibition. The beta3-induced current suppression was reversed at a HP of -120 mV, suggesting that the inhibition was voltage dependent. A high concentration of Ba(2+) (40 mM) as a charge carrier also largely diminished the effect of beta3 at -80 mV. Therefore, experimental conditions (HP, divalent cation concentration, and beta3 subunit concentration) approaching normal physiological conditions were critical to elucidate the full extent of this novel beta3 effect. Steady-state inactivation curves revealed that N-type channels exhibited "closed-state" inactivation without beta3, and that beta3 caused an approximately 40-mV negative shift of the inactivation, producing a second component with an inactivation midpoint of approximately -85 mV. The inactivation of N-type channels in the presence of a high concentration (12.5 ng/cell) of beta3 developed slowly and the time-dependent inactivation curve was best fit by the sum of two exponential functions with time constants of 14 s and 8.8 min at -80 mV. Similar "ultra-slow" inactivation was observed for N-type channels without beta3. Thus, beta3 can have a profound negative regulatory effect on N-type (and also R-type) calcium channels by causing a hyperpolarizing shift of the inactivation without affecting "ultra-slow" and "closed-state" inactivation properties.

In order to resolve a multiple sclerosis (MS) susceptibility locus that we had identified in earlier work at the telomeric end of the HLA complex, we genotyped another 34 microsatellite markers (47 in total) across the class I/extended class I region in 166 Tasmanian MS case and 104 control families (D6S299-D6S265). Extended MS susceptibility haplotypes, up to 9 Mb in length, were observed in 11% of MS cases and 4% of controls. Direct comparison of the telomerically extended portion of the MS susceptibility haplotype in HFE-Cys282Tyr (C282Y)-homozygous haemochromatosis patients identified a common ancestry for this genomic segment, which translated into an increased frequency of the C282Y allele in 489 MS cases from Tasmania and Victoria (10.2%) compared with controls (6.7%). Six C282Y homozygotes (1.2%), a three-fold increased rate over the general population, and 88 heterozygotes (18%) were identified. One C282Y-homozygous female was identified who had MS and was being treated for symptoms of iron overload. Interestingly, for 71 Victorian MS cases not of north western European (NWE) ancestry, a DR15-independent reduction in the frequency of the C282Y allele was observed, supporting the theory of a NWE origin for the C282Y-variant of the DR15 ancestral haplotype (C282Y-HLA-A*0301-B*0702-DRB1*1501-DQB1*0602). The results of linkage disequilibrium (LD) and log linear modelling analyses suggest that C282Y is increased in MS cases of NWE ancestry because it is in LD with the ancestral DR15 susceptibility haplotype (7.1) and that it does not play an independent role in predisposition to MS. However, our findings provide the impetus for further investigations into the role of iron metabolism in the severity of MS.

Ataxin 1 (Atx1) is a foci-forming polyglutamine protein of unknown function, whose mutant form causes type 1 spinocerebellar ataxia in humans and exerts neurotoxicity in transgenic mouse and fly expressing mutant Atx1. In this study, we demonstrate that Atx1 interacts with the transcriptional corepressor SMRT (silencing mediator of retinoid and thyroid hormone receptors) and with histone deacetylase 3. Atx1 binds chromosomes and mediates transcriptional repression when tethered to DNA. Interaction with SMRT-related factors is a conserved feature of Atx1, because Atx1 also binds SMRTER, a Drosophila cognate of SMRT. Significantly, mutant Atx1 forms aggregates in Drosophila, and such mutant Atx1-mediated aggregates sequester SMRTER. Consistently, the neurodegenerative eye phenotype caused by mutant Atx1 is enhanced by a Smrter mutation and, conversely, is suppressed by a chromosomal duplication that contains the wild type Smrter gene. Together, our results suggest that Atx1 is a transcriptional factor whose mutant form exerts its deleterious effects in part by perturbing corepressor-dependent transcriptional pathways.

Recent studies have suggested that a significant fraction of the human genome is contained in blocks of strong linkage disequilibrium, ranging from ~5 to >100 kb in length, and that within these blocks a few common haplotypes may account for >90% of the observed haplotypes. Furthermore, previous studies have suggested that common haplotypes in candidate genes are generally shared across populations and represent the majority of chromosomes in each population. The conclusions drawn from these preliminary studies, however, are based on an incomplete knowledge of the variation in the regions examined. To bridge this gap in knowledge, we have completely resequenced 100 candidate genes in a population of African descent and one of European descent. Although these genes have been well studied because of their medical importance, we demonstrate that a large amount of sequence variation has not yet been described. We also report that the average number of inferred haplotypes per gene, when complete data is used, is higher than in previous reports and that the number and proportion of all haplotypes represented by common haplotypes per gene is variable. Furthermore, we demonstrate that haplotypes shared between the two populations constitute only a fraction of the total number of haplotypes observed and that these shared haplotypes represent fewer of the African-descent chromosomes than was expected from previous studies. Finally, we show that restricting variation discovery to coding regions does not adequately describe all common haplotypes or the true haplotype block structure observed when all common variation is used to infer haplotypes. These data, derived from complete knowledge of genetic variation in these genes, suggest that the haplotype architecture of candidate genes across the human genome is more complex than previously suggested, with important implications for candidate gene and genomewide association studies.

Hepcidin is a circulating antimicrobial peptide mainly synthesized in the liver, which has been recently proposed as a factor regulating the uptake of dietary iron and its release by reticuloendothelial macrophages. Hepcidin is a potent mediator of anemia of inflammation. Disrupted hepcidin expression is thought to mediate the pathological effects of mutations in the HFE gene in hereditary hemochromatosis. Discovery of the critical role of hepcidin in iron homeostasis could help in the design of new therapies for some iron metabolism disorders in humans. The aim of this review is to summarize current knowledge about the function and regulation of hepcidin in iron metabolism.

<h4>Background</h4>Mutations in the GJB2 gene have been established as a major cause of inherited non syndromic deafness in different populations. A high number of sequence variations have been described in the GJB2 gene and the associated pathogenic effects are not always clearly established. The prevalence of a number of mutations is known to be population specific, and therefore population specific testing should be a prerequisite step when molecular diagnosis is offered. Moreover, population studies are needed to determine the contribution of GJB2 variants to deafness. We present our findings from the molecular diagnostic screening of the GJB2 and GJB6 genes over a three year period, together with a population-based study of GJB2 variants.<h4>Methods and results</h4>Molecular studies were performed using denaturing High Performance Liquid Chromatograghy (DHPLC) and sequencing of the GJB2 gene. Over the last 3 years we have studied 159 families presenting sensorineural hearing loss, including 84 with non syndromic, stable, bilateral deafness. Thirty families were genotyped with causative mutations. In parallel, we have performed a molecular epidemiology study on more than 3000 dried blood spots and established the frequency of the GJB2 variants in our population. Finally, we have compared the prevalence of the variants in the hearing impaired population with the general population.<h4>Conclusion</h4>Although a high heterogeneity of sequence variation was observed in patients and controls, the 35delG mutation remains the most common pathogenic mutation in our population. Genetic counseling is dependent on the knowledge of the pathogenicity of the mutations and remains difficult in a number of cases. By comparing the sequence variations observed in hearing impaired patients with those sequence variants observed in general population, from the same ethnic background, we show that the M34T, V37I and R127H variants can not be responsible for profound or severe deafness.

<h4>Background and purpose</h4>Focal cerebral ischemia causes microvessel matrix degradation and generates proteases known to degrade this matrix. However, proof that the proteases generated do indeed degrade vascular matrix is lacking. Here we demonstrate that active proteases derived from ischemic tissue after middle cerebral artery occlusion (MCAO) and transferred to normal tissue can degrade vascular matrix.<h4>Methods</h4>In an ex vivo bioassay, the effects of supernatants from ischemic and normal basal ganglia of nonhuman primates, proteases, and control buffer on the immunoreactivity of vascular matrix constituents in normal brain tissue sections were quantified. Protease families were identified with specific inhibitors.<h4>Results</h4>Plasmin, active matrix metalloproteinase (MMP)-2, and active MMP-9 significantly reduced microvessel-associated collagen, laminin, and heparan sulfate proteoglycans (HSPG). The vascular HSPG perlecan was more sensitive than collagen or laminin in the bioassay and in the ischemic core 2 hours after MCAO. Two-hour and 7-day ischemic tissue samples significantly degraded matrix perlecan and collagen. Inhibitor studies confirmed that while active MMPs were generated, active cysteine proteases significantly degraded microvessel perlecan. The cysteine proteases cathepsins B and L were generated in the microvasculature and adjacent neurons or glial cells 2 hours after MCAO and decreased perlecan in the bioassay.<h4>Conclusions</h4>This is the first direct evidence that active proteases are generated in ischemic cerebral tissues that are acutely responsible for vascular matrix degradation. Degradation of vascular perlecan, the most sensitive matrix component thus far identified, may be due to cathepsins B and L, generated very rapidly after MCAO.

There have been major basic advances in the field of iron metabolism in recent years. These advances include the discoveries of the HFE-1 gene, a series of transmembrane iron transporters or cotransporters (eg, divalent metal transporter-1, duodenal cytochrome b, ferroportin-1, hephaestin, and transferrin receptor-2), and two key regulatory proteins named hepcidin and hemojuvelin. Several mutations of these various proteins have been linked to human diseases. These discoveries have led to major improvements in our understanding of iron physiology and have also profoundly modified and extended the pathologic iron field. Clinical applications have rapidly emerged with the appearance of new iron overload syndromes and the practical input of new genetic tools enabling the noninvasive diagnosis of HFE-1 hemochromatosis. These basic advances are paving the road for innovative therapeutic strategies not only in iron overload syndromes but also in the wide area of chronic disease-related anemia.

<h4>Objectives</h4>To measure the frequency of genotypes of the HFE (haemochromatosis) gene in patients recruited to the west of Scotland coronary prevention study (WOSCOPS), and relate them to the subsequent occurrence of coronary clinical events.<h4>Design</h4>Nested case-control study, drawing samples of DNA from the biological bank of a cohort study.<h4>Patients</h4>Men aged 45-64 years in 1989, with moderate hypercholesterolaemia and no evidence of coronary heart disease at baseline.<h4>Interventions</h4>Follow up for a mean period of 4.9 years. Typing for C282Y and H63D mutations of the HFE gene in 482 subjects with a subsequent coronary event and 1104 without an event.<h4>Results</h4>The C282Y mutation was present in 81 of 482 cases (16.8%) and 182 of 1104 controls (16.5%). Comparing the prevalence of gene mutations in the cases and controls, there were no significant differences. The hazard ratio for C282Y heterozygotes was 1.03 (95% confidence interval (CI) 0.77 to 1.36) and for C282Y/H63D compound heterozygotes 1.04 (95% CI 0.50 to 2.14). Prespecified subgroup analyses of the pravastatin, placebo, smoking, and non-smoking groups showed no significant differences between cases and controls. Repeating the analyses after adjusting for possible confounding factors produced no change in the results.<h4>Conclusions</h4>In a population of moderately hypercholesterolaemic middle aged Scottish men who did not have any evidence of coronary heart disease at baseline, the presence of a C282Y mutation in the HFE gene did not predict the occurrence of coronary events over a mean follow up of 4.9 years.

<h4>Aim</h4>To test whether in vitro incubation of peripheral blood mononuclear cells (PBMC) with interferon (IFN) could efficiently decrease hepatitis C virus-RNA (HCV-RNA) amount and to analyze whether this effect was associated with clinical response to IFN.<h4>Methods</h4>Twenty-seven patients with histologically proven chronic hepatitis C were given intravenous administration of 6 million units (MU) IFN-beta daily for 6 weeks followed by three times weekly for 20 weeks. PBMC collected before IFN therapy were incubated with IFN-beta and HCV-RNA in PMBC was semi-quantitatively determined.<h4>Results</h4>Twenty-five patients completed IFN therapy. Eight patients (32%) had sustained loss of serum HCV-RNA with normal serum ALT levels after IFN therapy (complete responders). HCV-RNA in PBMC was detected in all patients, whereas it was not detected in PBMC from healthy subjects. In vitro administration of IFN-beta decreased the amount of HCV-RNA in PMBC in 18 patients (72%). Eight of these patients obtained complete response. On the other hand, none of the patients whose HCV-RNA in PBMC did not decrease by IFN-beta was complete responders. Multiple logistic regression analysis revealed that the decrease of HCV-RNA amount in PBMC by IFN-beta was the only independent predictor for complete response (P<0.05).<h4>Conclusion</h4>The effect of in vitro IFN-beta on HCV in PBMC reflects clinical response and would be taken into account as a predictive marker of IFN therapy for chronic hepatitis C.

Sox5 and Sox6 encode Sry-related transcription factors that redundantly promote early chondroblast differentiation. Using mouse embryos with three or four null alleles of Sox5 and Sox6, we show that they are also essential and redundant in major steps of growth plate chondrocyte differentiation. Sox5 and Sox6 promote the development of a highly proliferating pool of chondroblasts between the epiphyses and metaphyses of future long bones. This pool is the likely cellular source of growth plates. Sox5 and Sox6 permit formation of growth plate columnar zones by keeping chondroblasts proliferating and by delaying chondrocyte prehypertrophy. They allow induction of chondrocyte hypertrophy and permit formation of prehypertrophic and hypertrophic zones by delaying chondrocyte terminal differentiation induced by ossification fronts. They act, at least in part, by down-regulating Ihh signaling, Fgfr3, and Runx2 and by up-regulating Bmp6. In conclusion, Sox5 and Sox6 are needed for the establishment of multilayered growth plates, and thereby for proper and timely development of endochondral bones.

We analysed liver histology findings in a large cohort of patients with chronic hepatitis C and in roughly half of them their response to interferon-alpha-based on iron parameters and HFE status. Histological activity and virological response to antiviral therapy (n = 146) were analysed in 273 immunocompetent and nonalcoholic patients with chronic hepatitis C, in terms of serum iron load, intrahepatic iron load (n = 110) and HFE mutations. Patients who were heterozygous for the C282Y and H63D mutations exhibited higher iron serum parameters than subjects without these mutations. The intrahepatic iron load was higher in H63D patients only. No association was observed between HFE mutations and histological activity. Increased iron parameters were associated with liver disease severity by univariate analysis only. Genotype 1 and ferritinaemia were associated with a poor response to antiviral therapy, whereas the H63D mutation emerged as a positive predictive factor for end of treatment and sustained antiviral response. Therefore, in chronic hepatitis C patients serum and intrahepatic iron levels were weakly correlated with histological activity, while HFE mutations were not. As for the response to interferon-alpha, elevated ferritinaemia constituted a negative predictive factor whereas the H63D mutation was a positive one. The H63D mutation might form part of an immunogenetic profile influencing the response to interferon therapy.

The link between sex steroids and the development and growth of breast cancer has proved to be an invaluable clue for advances in the prevention and treatment of breast cancer. The identification of the oestrogen receptor (ER) not only allowed advances in the molecular endocrinology of oestrogen action, but also provided a target for antioestrogenic therapeutic agents. However, the application of long-term or indefinite treatment regimens has consequences for the breast cancer. New forms of resistance, based upon enhanced cellular survival networks independent of ER and the suppression of apoptotic mechanisms, develop and then evolve. Remarkably, low concentrations of oestrogen collapse survival pathways and induce apoptosis in completely antihormonally refractory breast cancer. However, recurrent oestrogen-stimulated disease is again sensitive to antihormonal therapy. The novel reapplication of the ER as a therapeutic target for apoptosis is emerging as a new strategy for the long-term targeted maintenance treatment of breast cancer, and in formulating a targeted strategy for endocrine independent cancer.

Huntington's disease (HD) is a devastating neurodegenerative disorder caused by a CAG repeat expansion encoding an extended polyglutamine tract in the huntingtin protein. Transgenic mice expressing a human huntingtin transgene containing an expanded CAG repeat (R6/1 model) develop a neurodegenerative disorder closely resembling human HD. Previous work demonstrated that environmental enrichment delays the onset of motor symptoms in this mouse model. We confirmed that at 5 months of age, enrichment ameliorates motor symptoms (assessed using the rotarod test) and prevents loss of body weight induced by the HD transgene. We further examined molecular consequences of enrichment by determining changes in protein levels in the neostriatum, hippocampus, and anterior cortex using quantitative Western blot analysis. Non-enriched HD mice have severe reductions in BDNF in the hippocampus and striatum at 5 months, which are entirely rescued by enrichment. BDNF levels are unaltered by HD in the anterior cortex, suggesting that enrichment might prevent HD-induced impairment of anterograde transport of this neurotrophin to the striatum. NGF is unaffected by HD. Non-enriched HD mice also exhibit deficits in dopamine and cAMP-regulated phosphoprotein (32 kDa) in striatum and anterior cortex. Environmental enrichment rescues the cortical but not the striatal deficit at 5 months. These results suggest that environmental enrichment benefits animals at early stages of the disease by rescuing protein deficits, possibly through rescuing transcription or protein transport problems.

Hepcidin (HEPC) plays a key role in iron homeostasis and an abnormally low level of hepcidin mRNA has been reported in HFE-1 genetic hemochromatosis. Considering the well-known phenotypic variability of this disease, especially between men and women, it is important to define factors susceptible to modulate hepatic hepcidin expression and, consequently, to influence the development of iron overload in HFE-1 hemochromatosis. Therefore, our aim was to analyze the effects of strain and gender on hepatic hepcidin expression in the mouse. C57BL/6 and DBA/2 wild-type mice were included in this study. Liver and splenic iron contents were measured. Specific hepatic Hepc1 and Hepc2 mRNA levels were quantified using real-time reverse transcription polymerase chain reaction (RT-PCR). C57BL/6 mice expressed predominantly Hepc1 mRNA, whereas Hepc2 mRNA was the main form in DBA/2 mice. In both strains, females had higher levels of iron stores and Hepc mRNAs compared to males. Our results demonstrate that the expression of both hepcidin mRNAs varies according to strain and gender. They suggest that sex and genetic background, which are regulators of hepcidin expression, could play a role in the phenotypic expression of genetic hemochromatosis.

The OX40 (CD134) molecule is induced primarily during T cell activation and, as we show in this study, is also expressed on CD25+CD4+ regulatory T (Treg) cells. A necessary role for OX40 in the development and homeostasis of Treg cells can be inferred from the reduced numbers of the cells present in the spleens of OX40-deficient mice, and their elevated numbers in the spleens of mice that overexpress the OX40 ligand (OX40L). The homeostatic proliferation of Treg cells following transfer into lymphopenic mice was also found to be potentiated by the OX40-OX40L interaction. Suppression of T cell responses by Treg cells was significantly impaired in the absence of OX40, indicating that, in addition to its homeostatic functions, OX40 contributes to efficient Treg-mediated suppression. However, despite this, we found that CD25-CD4+ T cells became insensitive to Treg-mediated suppression when they were exposed to OX40L-expressing cells, or when they were treated with an agonistic OX40-specific mAb. OX40 signaling could also abrogate the disease-preventing activity of Treg cells in an experimental model of inflammatory bowel disease. Thus, although the data reveal important roles for OX40 signaling in Treg cell development, homeostasis, and suppressive activity, they also show that OX40 signals can oppose Treg-mediated suppression when they are delivered directly to Ag-engaged naive T cells.

The production of therapeutic proteins in mammalian cell lines is of outstanding importance. The maintenance of most mammalian cell lines in culture requires the addition of serum to the culture medium. The elimination of serum from mammalian cell culture is desirable since serum is expensive and a source of contaminants, e.g. viruses, mycoplasma or prions. Here we describe the composition of serum- and protein-free media for the Chinese hamster ovary (CHO) cell line DUKXB11. The serum-free formulation supports excellent growth of CHO DUKXB11 cells at low (23cells/cm2) and high (2 x 10(4) cells/cm2) seeding densities characterized by a generation time of 10-12h, and, after addition of 0.2% pluronic F-68, the growth of a recombinant suspension cell line derived from DUKXB11. In addition, this formulation also allowed us to adapt recombinant cell lines expressing various amounts of human antithrombin ATIII (ATIII) to serum-free conditions. Secretion of ATIII was readily observed in the serum-free medium. Minor changes to the serum-free formulation resulted in a protein free formulation that supported growth of CHO DUKXB11 cells, growth of recombinant CHO cells expressing ATIII, and production of ATIII.

Previously, we have shown that repeated administration of d-fenfluramine (D-F) to rats is associated with development of tolerance to the initial anorexia, but that in mice no such tolerance seems to occur. In the first study, we show that chronic administration of neither d-norfenfluramine (D-NF; the principal metabolite of D-F) nor the serotonin (5-HT) 2C receptor agonist m-chlorophenyl-piperazine (mCPP) is associated with the development of anorectic tolerance tested using a dessert protocol. However, compared with mice receiving these drugs for the first time, both of these chronic treatments were associated with a significant attenuation of Fos immunoreactivity (Fos-ir) in several brain regions, including bed nucleus of the stria terminalis, paraventricular hypothalamus, and central nucleus of amygdala. This attenuation is similar to that described previously in rats. Because loss of efficacy of these agents could be related to loss of 5-HT transporter (5-HTT) sites, their presumptive primary mode of action, in the final study we determined the effect of various, low-dose regimens of D-F and D-NF on 5-HT uptake in frontal cortex of mice and rats. We show in mice that D-F causes a greater loss of 5-HT uptake than D-NF, and that at the lowest dose regimen used uptake was unaffected in rats but was reduced in mice. The data are discussed in terms of the species difference in behavioral tolerance and differences in neurochemical profile of D-F and D-NF.

Aggregation of conformation-abnormal peptides probably plays a key role in the pathogenesis of many neurodegenerative diseases. DSCR1 Down syndrome (DS) critical region 1, was identified from a chromosomal region (21q22.1-q22.2) for the clinical manifestations of DS when an extra-copy is present. We report that expression of DSCR1 in several cell types, including primary neurons, causes microtubule-dependent aggresome-like inclusion body formation. Disease-associated huntingtin (Q148) and ataxin-3 (Q84) co-localize with DSCR1 aggregates. Neurons bearing DSCR1 aggregates show reduced synaptophysin staining in processes. DSCR1 residues 31-90 constitute an aggregation-prone domain that is predicted to form a hydrophobic patch on the protein surface when residues 1-30 are removed. This study identifies a novel function of DSCR1 that may underlie DS neuropathology.

A promoter (sufAp), inducible by various oxidants, directs transcription of the sufABCDSE operon encoding an alternative Fe-S cluster assembly system in Escherichia coli. Superoxide generators and H2O2 induced expression of sufA-lacZ even in DeltasoxRS and DeltaoxyR mutants, suggesting participation of an additional regulator(s) in oxidant induction of the sufA operon. Through deletion and linker scanning mutagenesis, we found three cis-acting oxidant-responsive elements (OREs). ORE-I lies between -236 and -197 nucleotides from the transcription start site, overlapping extensively with the OxyR binding site reported previously. ORE-II (-156 to -127) was found to be the site of IHF action. ORE-III (-56 to -35) had no predictable binding sites for known regulators. Gel mobility shift assays with a 50 bp DNA probe containing ORE-III revealed the presence of an ORE-III-specific factor that binds only when cells are treated with oxidants. S1 mapping analysis revealed that phenazine methosulphate (PMS) and H2O2 induced sufA expression by more than 40-fold. In a DeltaoxyR mutant, sufA was still induced more than 10-fold. Fur, a ferric uptake regulator that negatively regulates this operon in response to iron availability, did not mediate the oxidant induction. Deletion of the suf operon caused cells to be more sensitive to superoxide-generating agents without affecting sensitivity to H2O2. From these results, we propose that the oxidant induction of the sufA operon is mediated through OxyR, IHF, plus an unidentified oxidant-responsive factor, and that the suf gene products are needed to defend cells against oxidative stress caused by superoxide generators.

<h4>Purpose</h4>EBV has been detected in 2-16% of gastric carcinomas. However, there is little information available about the gene expression profile of EBV-positive gastric carcinomas.<h4>Experimental design</h4>EBV infection was examined using EBV-encoded small RNAs (EBERs) in situ hybridization, and 63 (5.6%) of 1127 consecutive gastric carcinomas were found to be EBV-positive. The expressions of 27 tumor-associated proteins were evaluated immunohistochemically in 63 EBV-positive gastric carcinomas and 287 EBV-negative carcinomas using the tissue array method. In addition, the genotype of EBV was investigated by PCR amplification of LMP1 (latent membrane protein 1), Epstein-Barr nuclear antigen 2 (EBNA2), and EBNA3B genes.<h4>Results</h4>EBV-positive gastric carcinomas are characterized by the presence of lymphoid stroma, proximal location, and predominance in males. In comparison with EBV-negative carcinomas, EBV-positive carcinomas showed frequent loss of expression of p16, smad4, FHIT, and KAI-1 (kangai 1; P < 0.05), but retained the expression of APC (adenomatous polyposis coli), DCC (deleted in colorectal cancer), and some DNA repair proteins (P < 0.05). There was negative association between EBV infection and the expression of MUC1, MUC2, MUC5AC, p53, CEA, C-erbB2, and smad7. Using hierarchical cluster analysis, we divided EBV-positive gastric carcinomas into two clusters. Those patients with cluster 1 (42 cases) carcinomas had a better prognosis than those with cluster 2 (12 cases; P = 0.0002) or those with EBV-negative carcinomas (280 cases; P = 0.0251). Fifty-one (92.7%) of 55 EBV-positive carcinomas demonstrated the 30-bp deletion in LMP1 gene, and 53 (96.4%) of 55 cases were type 1 for EBNA2 and EBNA3B genes.<h4>Conclusion</h4>EBV-positive gastric carcinomas have a distinct protein expression profile as well as distinct clinicopathological features, as compared with EBV-negative carcinomas. The subclassification of EBV-positive carcinomas, by hierarchical cluster analysis, is significantly associated with patient survival.

Evidence suggests N-methyl-D-aspartate receptor (NMDAR) activation is involved in the degeneration of striatal medium-sized spiny neurons (MSNs) in Huntington's disease (HD). We tested the hypothesis that enhanced NMDAR-mediated excitotoxicity is mediated by the mitochondrial-associated apoptotic pathway in cultured MSNs from YAC transgenic mice expressing full-length huntingtin (htt) with a polyglutamine (polyQ) expansion of 46 or 72 (YAC46 or YAC72). NMDAR-mediated Ca(2+) transients and mitochondrial membrane depolarization were significantly increased in YAC compared to wild-type mice MSNs. Inhibitors of the mitochondrial permeability transition (mPT), cyclosporin A and bongkrekic acid, and coenzyme Q10 (an anti-oxidant involved in bioenergetic metabolism) dramatically diminished NMDA-induced cell death and eliminated genotypic differences. In YAC46 MSNs, NMDA stimulated significantly higher activation of caspase-3 and caspase-9 but not caspase-8, and NMDA-induced caspase-3 and -9 activation was markedly attenuated by cyclosporin A. Agents that improve mitochondrial function or inhibit the permeability transition may eliminate increased caspase activation and cell death associated with enhanced NMDAR activity in HD.

At least nine inherited neurodegenerative diseases share a polyglutamine expansion in their respective disease proteins. These diseases show distinct neuropathological changes, suggesting that protein environment and protein-protein interactions play an important role in the specific neuropathology. A gain of toxic function as a result of an expanded polyglutamine tract can cause the protein huntingtin to interact abnormally with a variety of proteins, resulting in the complex of neuropathological changes seen in Huntington's disease. Recent studies have identified several huntingtin-interacting proteins that might be associated with the normal function of huntingtin and/or involved in the pathology of Huntington's disease. In this article, we focus on the potential roles of huntingtin-protein interactions in the pathogenesis of Huntington's disease.

In many CNS pathways, target innervation occurs by axon branching rather than extension of the primary growth cone into targets. To investigate mechanisms of branch formation, we studied the effects of attractive and inhibitory guidance cues on cortical axon branching. We found that netrin-1, which attracts cortical axons, and FGF-2 increased branching by >50%, whereas semaphorin 3A (Sema3A), which repels cortical axons, inhibited branching by 50%. Importantly, none of the factors affected axon length significantly. The increase in branching by FGF-2 and the inhibition of branching by Sema3A were mediated by opposing effects on the growth cone (expansion vs collapse) and on the cytoskeleton. FGF-2 increased actin polymerization and formation of microtubule loops in growth cones over many hours, whereas Sema3A depolymerized actin filaments, attenuated microtubule dynamics, and collapsed microtubule arrays within minutes. Netrin-1 promoted rapid axon branching, often without involving the growth cone. Branches formed de novo on the axon shaft within 30 min after local application of netrin-1, which induced rapid accumulation of actin filaments in filopodia. Importantly, increased actin polymerization and microtubule dynamics were necessary for axon branching to occur. Taken together, these results show that guidance factors influence the organization and dynamics of the cytoskeleton at the growth cone and the axon shaft to promote or inhibit axon branching. Independent of axon outgrowth, axon branching in response to guidance cues can occur over different time courses by different cellular mechanisms.

Protein kinase A (PKA) exerts a profound influence on axon extension during development and regeneration; however, the molecular mechanisms underlying these effects of PKA are not understood. Here, we show that DCC (deleted in colorectal cancer), a receptor for the axon guidance cue netrin-1, is distributed both at the plasma membrane and in a pre-existing intracellular vesicular pool in embryonic rat spinal commissural neurons. We hypothesized that the intracellular pool of DCC could be mobilized to the plasma membrane and enhance the response to netrin-1. Consistent with this, we show that application of netrin-1 causes a modest increase in cell surface DCC, without increasing the intracellular concentration of cAMP or activating PKA. Intriguingly, activation of PKA enhances the effect of netrin-1 on DCC mobilization and increases axon extension in response to netrin-1. PKA-dependent mobilization of DCC to the plasma membrane is selective, because the distributions of transient axonal glycoprotein-1, neural cell adhesion molecule, and trkB are not altered by PKA in these cells. Inhibiting adenylate cyclase, PKA, or exocytosis blocks DCC translocation on PKA activation. These findings indicate that netrin-1 increases the amount of cell surface DCC, that PKA potentiates the mobilization of DCC to the neuronal plasma membrane from an intracellular vesicular store, and that translocation of DCC to the cell surface increases axon outgrowth in response to netrin-1.

The neurons generated at the germinal rhombic lip undergo long distance migration along divergent pathways to settle in widely dispersed locations within the hindbrain, giving rise to cerebellar granule cells and precerebellar nuclei. Neurotrophin-3 (NT-3) signaling has been shown to be required for proper migration and survival of cerebellar granule cells. The molecular bases that govern NT-3 expression within the cerebellum, however, remain unknown at present. Here we report that, during early mouse neurogenesis, the Barhl1 homeobox gene is highly expressed by the rhombic lip and rhombic lip-derived migratory neurons. Its expression is later restricted to cerebellar granule cells and precerebellar neurons extending mossy fibers, two groups of neurons that synaptically connect in the adult cerebellar system. Loss of Barhl1 function causes cerebellar phenotypes with a striking similarity to those of NT-3 conditional null mice, which include attenuated cerebellar foliation as well as defective radial migration and increased apoptotic death of granule cells. Correlating with these defects, we find that NT-3 expression is dramatically downregulated in granule cells of the posterior lobe of Barhl1(-)/- cerebella. Moreover, in the precerebellar system of Barhl1(-/-) mice, all five nuclei that project mossy fibers fail to form correctly because of aberrant neuronal migration and elevated apoptosis. These results suggest that Barhl1 plays an essential role in the migration and survival of cerebellar granule cells and precerebellar neurons and functionally link Barhl1 to the NT-3 signaling pathway during cerebellar development.

<h4>Background</h4>Maspin is a serpin family of protease inhibitors. Althouth maspin has been considered a tumor suppressor that inhibits the motility, invasion, and metastasis of breast and prostatic cancer cells, there are many conflicting reports about maspin expression and cancer prognosis.<h4>Methods</h4>To investigate whether the expression of maspin could be used as a prognostic marker in pancreatic cancer, 72 paraffin-embedded pancreatic ductal adenocarcinomas were analyzed using immunohistochemistry. We examined the prognostic value of maspin as well as its relationship with clinicopathological features.<h4>Results</h4>Maspin expression was observed in all pancreatic ductal adenocarcinoma. Unlike cancer tissues, however, faint or no expression was observed in the corresponding normal pancreatic tissues. In the Cox proportional hazard model, high maspin expression predicted a high hazard rate. Maspin expression had a positive correlation with tumor stage, but there were also no statistically significant relationships between maspin expression and other clinicopathological features.<h4>Conclusion</h4>These findings suggest maspin expression to have biological relevance in the progression of pancreatic cancers, with potential use as a prognostic marker for pancreatic neoplasm with epithelial origin.

<h4>Background</h4>Nonalcoholic fatty liver disease (NAFLD) has been more and more often regarded as a serious disorder, because nonalcoholic steatohepatitis (NASH), a part of NAFLD, may progress to the end stage of liver disease. Though an advanced age, obesity, diabetes mellitus (DM) etc. being not infrequent conditions in Korea, are known to exacerbate the severity of this disease, there are only a few Korean reports on this subject. The purpose of this study is to identify possible factors that might add up to the pathological severity of this disorder in Korean patients.<h4>Methods</h4>Of 60 patients with steatosis found at liver biopsy, 43 NAFLD patients were reviewed retrospectively after exclusion of other liver diseases.<h4>Results</h4>The cases of steatosis were mild, moderate, and severe in 9. 10, and 24 patients, respectively. The degree of necroinflammatory activity was mild, moderate, and severe in 33, 9, and 1 patients, respectively. There were no established factors directly related to these classes. As to fibrosis, the cases were classified as none, mild, moderate, severe, and cirrhotic in 9, 11, 16, 7, and 0 patients, respectively. The stage of fibrosis correlated with the age (p < 0.001), BMI (body mass index) (p = 0.032), and the platelet count (p = 0.009), but the presence of NASH was associated only with BMI (p = 0.002) and obesity (p = 0.001).<h4>Conclusion</h4>It seems that there are no factors that are directly related to the degree of steatosis or necroinflammatory activity. BMI seems to be a unique factor directly related to both the severity of fibrosis and the presence of NASH. The age and the platelet count are factors that are directly related to the degree of fibrosis but not to the presence of NASH.

The visual appearance of the fingernails and toenails may suggest an underlying systemic disease. Clubbing of the nails often suggests pulmonary disease or inflammatory bowel disease. Koilonychia, or "spoon-shaped" nails, may stimulate a work-up for hemochromatosis or anemia. In the absence of trauma or psoriasis, onycholysis should prompt a search for symptoms of hyperthyroidism. The finding of Beau's lines may indicate previous severe illness, trauma, or exposure to cold temperatures in patients with Raynaud's disease. In patients with Muehrcke's lines, albumin levels should be checked, and a work-up done if the level is low. Splinter hemorrhage in patients with heart murmur and unexplained fever can herald endocarditis. Patients with telangiectasia, koilonychia, or pitting of the nails may have connective tissue disorders.

Axon pathfinding and target recognition are highly dynamic and tightly regulated cellular processes. One of the mechanisms involved in regulating protein activity levels during axonal and synaptic development is protein ubiquitination. We describe here the isolation of several Caenorhabditis elegans mutants, termed eno (ectopic/erratic neurite outgrowth) mutants, that display defects in axon outgrowth of specific neuron classes. One retrieved mutant is characterized by abnormal termination of axon outgrowth in a subset of several distinct neuron classes, including ventral nerve cord motor neurons, head motor neurons, and mechanosensory neurons. This mutant is allelic to lin-23, which codes for an F-box-containing component of an SCF E3 ubiquitin ligase complex that was previously shown to negatively regulate postembryonic cell divisions. We demonstrate that LIN-23 is a broadly expressed cytoplasmically localized protein that is required autonomously in neurons to affect axon outgrowth. Our newly isolated allele of lin-23, a point mutation in the C-terminal tail of the protein, displays axonal outgrowth defects similar to those observed in null alleles of this gene, but does not display defects in cell cycle regulation. We have thus defined separable activities of LIN-23 in two distinct processes, cell cycle control and axon patterning. We propose that LIN-23 targets distinct substrates for ubiquitination within each process.

<h4>Background</h4>A large proportion of US adults have elevated transferrin saturation, an indicator of a predisposition for iron overload. The purpose of this study was to evaluate the relationship between elevated serum transferrin saturation and mortality.<h4>Methods</h4>This cohort study was conducted using data from the First Health and Nutrition Examination Survey 1 (1971-1974) (NHANES I) merged with the NHANES I Epidemiologic Followup Study (1992) (N = 10,714). We used SUDAAN and appropriate weights to make population estimates for the adult US population (aged 25 to 74 years at baseline). All-cause mortality was evaluated in relation to serum transferrin saturation of greater than 45%, greater than 50%, greater than 55%, and greater than 60% using Cox proportional hazards regression.<h4>Results</h4>In a Cox proportional hazards model controlling for potential confounders, including comorbid diseases, smoking, and cholesterol, all-cause mortality is significantly greater for persons with a serum transferrin saturation of more than 55%, compared with those with saturations below this cutoff (hazards ratio [HR] = 1.60, 95% confidence interval [CI], 1.17-2.21). No one who died had hemochromatosis as any of the 20 listed causes of death. Many of the underlying causes of death for persons with serum transferrin saturation levels of more than 55% are common causes of death in the general population, although these persons were more likely to have died of cirrhosis and diabetes, a finding consistent with iron overload.<h4>Conclusions</h4>In this nationally representative cohort of adults, those with elevated serum transferrin saturation, more than 2% of the adult US population, were at increased risk for all-cause mortality.

<h4>Background</h4>Recent data shows an increased mortality risk associated with elevated transferrin saturation. Because ingestion of dietary iron may contribute to iron overload in persons with elevated transferrin saturation, we investigated the relationship between elevated transferrin saturation, ingestion of dietary iron and red meat, and mortality.<h4>Methods</h4>This 12-year cohort study used data from the second National Health and Nutrition Examination Survey 1976-1980 (NHANES II) and the NHANES II Mortality Study 1992. Population estimates were based on 9,229 persons aged 35 to 70 years at baseline. A Cox proportional hazards analysis was performed based on levels of transferrin saturation, intake of dietary iron, and intake of red meat. The analysis was conducted while controlling for demographics, severity of illness, body mass index, and smoking status.<h4>Results</h4>Unadjusted analyses indicated that those who had a high transferrin saturation and reported high dietary iron or red meat consumption had an increased mortality risk. The adjusted survival analysis indicated that persons with elevated transferrin saturation who reported high dietary iron intake had a hazard ratio for death of 2.90 (95% confidence interval [CI], 1.39-6.04) compared with those with normal transferrin saturation levels and reported low dietary iron intake. Persons who had a high transferrin saturation and reported high red meat consumption also had an increased hazard ratio for death (2.26; 95% CI, 1.45-3.52) compared with those who had normal transferrin saturation and reported low red meat consumption.<h4>Conclusions</h4>Ingestion of large quantities of dietary iron and red meat in persons with high transferrin saturation is associated with an increase in mortality. Simple dietary restrictions may reduce the mortality risk associated with high transferrin saturation.

Alterations in the serotonin transporter (5-HTT) have been implicated in a variety of psychiatric disorders including cocaine dependence. A polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) appears to influence the expression of 5-HTT in human cell lines. We investigated whether 5-HTTLPR variants were related to differences in measures of platelet 5-HTT sites in cocaine-dependent patients and healthy volunteers (controls). Polymerase chain reaction-based genotyping of a 44 base pair insertion/deletion polymorphism in 5-HTTLPR was performed in 138 cocaine-dependent African-American subjects and 60 African-American controls. This yielded a short (S) and a long (L) allele. Platelet 5-HTT sites were measured using the tritiated paroxetine binding assay. Relationships of 5-HTTLPR genotypes with Bmax (density of serotonin transporter) and Kd (affinity constant) were examined. Bmax values were significantly lower in cocaine-dependent patients (640 +/- 233) than controls (906 +/- 225) (P < 0.001); however, 5-HTTLPR genotype distributions or allele frequencies did not differ between the two groups. There were no significant differences in Bmax between the three genotypes among cocaine-dependent patients (LL = 690 +/- 246, LS = 620 +/- 235, SS = 587 +/- 183; P = 0.14) or controls (LL = 909 +/- 233, LS = 938 +/- 279, SS = 866 +/- 143; P = 0.65). All three genotypes in cocaine-dependent patients showed comparable reductions in Bmax from the corresponding genotypes in controls. Demographic variables, severity of substance use or depression were unrelated to Bmax or 5-HTTLPR genotypes. Although platelet 5-HTT densities are reduced in patients with cocaine dependence compared with healthy volunteers, these genotypic variations in the serotonin transporter do not seem to influence levels of platelet 5-HTT in cocaine-dependent patients or healthy volunteers.

The role of the serotonin system in the etiology and pathogenesis of autism spectrum disorders (ASD) is not clearly defined. High levels of platelet serotonin (5-HT) have been consistently found in a proportion of patients, and it is known that specific 5-HT transporter gene (SLC6A4) variants modulate transporter reuptake function, therefore possibly influencing the occurrence of hyperserotonemia in a subset of autistic patients. We have examined the association of platelet serotonin levels with two SLC6A4 polymorphisms, 5-HTT gene-linked polymorphic region (HTTLPR) in the promoter and intron 2 variable number of tandem repeats (VNTR), in a sample of 105 ASD patients, their parents, and 52 control children. Quantitative transmission disequilibrium test (QTDT) results showed a significant effect on 5-HT levels of each SLC6A4 marker (P=0.017 for HTTLPR; P=0.047 for intron 2 VNTR) and of haplotypes of the two markers (P=0.017), with a major contribution of the L.Stin2.10 haplotype (P=0.0013). A 5-HT mean value in the range of hyperserotonemia was associated with the homozygous L.Stin2.10 haplotype (H (1,N=97)=7.76, P=0.0054), which occurred in 33% of hyperserotonemic patients against 6% of patients with normal 5-HT levels (Fisher's exact test: P=0.013, OR=8). Allele interaction at the HTTLPR locus was found, with a significant dominance variance effect on 5-HT levels. We found no transmission disequilibrium of any of the SLC6A4 variants in ASD. Our results show that the SLC6A4 gene is a significant factor in the determination of 5-HT levels, and that specific SLC6A4 variants are associated with an increased risk for hyperserotonemia in our sample of autistic patients. The biological mechanism, however, is unlikely to involve the SLC6A4 gene solely. The associated SLC6A4 alleles likely interact with other genes or environmental factors to produce the abnormally high 5-HT levels observed in this subset of autistic patients, who possibly represent a separate etiological group.

Familial hypokalemic periodic paralysis is an autosomal dominant genetic muscle disease characterized by periodic attacks of muscle weakness associated with a decrease in serum potassium. There are two major missense mutation sites in the calcium channel alpha1 subunit (CACNA1S) gene in these patients. We recently encountered a 13-year-old Japanese boy who had collapsed following exercise and was found to have a low serum potassium level. Clinical and genetic studies including exploration of his family tree proved that he and his maternal relatives had the disease with the missense mutation, Arg528His (CGC --> CAC). However, his mother and grandmother had no symptoms of the disease, indicating reduced penetrance in female carriers. Sexual difference in the penetrance of this disease and the association between the clinical symptoms and the types of genetic defects are discussed.

Familial (hereditary) haemochromatosis (HH) is an iron storage disorder characterized by an increased intestinal absorption of iron and its accumulation in numerous tissues. The disease generates an iron overload with tissue damages also seen in haematologic disturbances (with dyserythropoiesis and haemolysis) and hepatic disorders. Besides typical mutations linked to HH (C282 Y and H63D, HFE locus), three other mutations have been identified and more have to be defined. A complete genetic testing is important to assess the risk of morbidity. Indeed, the clinical picture of HH is dependent upon the specific mutations as well as the individual context (sex, environment, associated hepatic and/or haematologic disorders). Porphyria cutanea tarda (PCT) has for long been found significantly associated with HH. It is now considered that hepatic iron overload related to the combination of heterogeneous genetic traits and environmental factors, including alcoholism and viral hepatitis, precipitates the expression of PCT through the inhibition of uroporphyrinogen decarboxylase (Uro.D).

In this study we screened 3060 consecutive blood donors for an unbound iron-binding capacity level of <28 microM and then performed HFE mutation analysis in these subjects. Sixty-five of the 75 subjects with a low initial unbound iron-binding capacity (all had normal ferritin levels) came back and only 5 (8%) had a low fasting unbound iron-binding capacity. Mutational analysis revealed H63D heterozygosity in two of five subjects. Four of five subjects had liver biopsy indication and none had increased liver iron. HFE genotyping of 60 subjects with a low initial but normal fasting unbound iron-binding capacity revealed heterozygote H63D in seven (11.6%). No allelic variant of position 282 or 63 was found in three previously diagnosed patients with hereditary hemochromatosis. In conclusion, full phenotypic expression of hereditary hemochromatosis is very rare in Turkey. The absence of HFE mutations in three patients with hereditary hemochromatosis suggests that hereditary hemochromatosis in Turkey occurs without common HFE mutations.

It was reported that three polymorphic genes were identified to be able to potentially influence the bioaccumulation and toxicokinetics of lead in humans. These genes are delta-aminolevulinic acid dehydratase(ALAD) gene, vitamin D receptor (VDR) and hemochromatosis gene. Their relation to susceptibility to lead poisoning in humans was reviewed in this paper.

Our understanding of nutrient absorption continues to grow, from the development of unique animal models and from studies in which cutting-edge molecular and cellular biologic approaches have been used to analyze the structure and function of relevant molecules. Studies of the molecular genetics of inherited disorders have also provided many new insights into these processes. A major advance in lipid absorption has been the cloning and characterization of several intestinal acyl CoA:monoacylglycerol acyltransferases; these may provide new targets for antiobesity drug therapy. Studies of intestinal cholesterol absorption and reverse cholesterol transport have encouraged the development of novel potential treatments for hyperlipidemia. Observations in genetically modified mice and in humans with mutations in glucose transporter 2 suggest the importance of a separate microsomal membrane transport pathway for glucose transport. The study of iron metabolism has advanced greatly with the identification of the hemochromatosis gene and the continued examination of the genetic regulation of iron absorptive pathways. Several human thiamine transporters have been identified, and their specific roles in different tissues are being explored.

The analysis of genetic variation in candidate genes is an issue of central importance in pharmacogenomics. The specific approaches taken will have a critical impact on the successful identification of disease genes, the molecular correlates of drug response, and the establishment of meaningful relationships between genetic variants and phenotypes of biomedical and pharmaceutical importance in general. Against a historical background, this article distinguishes different approaches to candidate gene analysis, reflecting different stages in human genome research. Only recently has it become feasible to analyze genetic variation systematically at the ultimate level of resolution, ie, the DNA sequence. In this context, the importance of haplotype-based approaches to candidate gene analysis has at last been recognized; the determination of the specific combinations of variants for each of the two sequences of a gene defined as a haplotype is essential. An up-to-date summary of such maximum resolution data on the amount, nature, and structure of genetic variation in candidate genes will be given. These data demonstrate abundant gene sequence and haplotype diversity. Numerous individually different forms of a gene may exist. This presents major challenges to the analysis of relationships between genetic variation, gene function, and phenotype. First solutions seem within reach. The implications of naturally occurring variation for pharmacogenomics and "personalized" medicine are now evident. Future approaches to the identification, evaluation, and prioritization of drug targets, the optimization of clinical trials, and the development of efficient therapies must be based on in-depth knowledge of candidate gene variation as an essential prerequisite.

No abstract available.