Promoter hypermethylation silences expression of the HoxA4 gene and correlates with IgVh mutational status in CLL.
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Biomedical subjects
Publications and source records attributed to A Parker.
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The Ensembl (http://www.ensembl.org/) project provides a comprehensive and integrated source of annotation of large genome sequences. Over the last year the number of genomes available from the Ensembl site has increased from 4 to 19, with the addition of the mammalian genomes of Rhesus macaque and Opossum, the chordate genome of Ciona intestinalis and the import and integration of the yeast genome. The year has also seen extensive improvements to both data analysis and presentation, with the introduction of a redesigned website, the addition of RNA gene and regulatory annotation and substantial improvements to the integration of human genome variation data.
This study investigates whether the immediate early gene (IEG) products c-Fos and c-Jun are activated in vivo in monkeys with experimental glaucoma, and in vitro in cultured human ONH astrocytes exposed to hydrostatic pressure (HP). Three Rhesus monkeys with mild glaucomatous damage (mean intraocular pressure (IOP) 27 +/- 1.3 mm Hg approximately 42 weeks) and three with moderate glaucomatous damage (mean IOP 44 +/- 6.7% mm Hg approximately 11 weeks) were used for this study; the contralateral eye served as normal control (mean IOP 18.6 +/- 1.7 mm Hg). ONH tissues were stained with GFAP, DAPI, and c-Jun or c-Fos, and transcription factor positive and negative nuclei were counted to determine nuclear localization. Cultured human normal and glaucomatous ONH astrocytes exposed to elevated HP served as the in vitro model of elevated pressure. Activation and nuclear localization of c-Fos and c-Jun increased significantly in the monkeys with elevated IOP. These data correlated with axonal loss, reactive astrocytes, and remodeling of the optic disc. Cultured human ONH astrocytes showed increased nuclear localization of c-Fos and c-Jun under exposure to HP. Immunohistochemistry demonstrated that the upstream regulators of c-Fos and c-Jun, ERK-MAPK and MAPKp38 localized to the nuclei of ONH astrocytes in monkeys with experimental glaucoma. Taken together, these results demonstrate c-Fos and c-Jun activation in ONH astrocytes in vivo and in vitro, and that activation of both transcription factors is associated with ERK and MAPKp38 activation in experimental glaucoma, suggesting that activation of transcription factors may participate in the induction and maintenance of the reactive astrocyte phenotype in glaucomatous optic neuropathy.
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Donor lymphocyte infusion (DLI) can restore remission in a high percentage of patients with chronic myeloid leukaemia (CML) who relapse after allogeneic stem cell transplant (SCT). Subsequent relapses after a DLI-induced remission do occur and the optimal management of these patients is not defined. A retrospective study of the practice of UK transplant centres was conducted. In all, 13 patients from seven centres were identified: all were treated for relapse post allogeneic SCT with DLI and achieved either a complete cytogenetic (n=5) or molecular (n=8) remission. All patients subsequently had a second relapse, at molecular (n=7), cytogenetic (n=4) and haematological (n=2) levels. Further DLI was used in the treatment of 11 patients, imatinib mesylate in three and chemotherapy in two. The two patients with haematological relapse died of blastic disease. The remaining 11 patients achieved either a complete cytogenetic (n=2) or molecular (n=9) remission. Nine patients remain in molecular remission at a median follow-up of 29 months, seven of whom had received DLI alone as treatment for second relapse, one DLI plus imatinib and one imatinib alone. Toxicity following DLI for second relapse was low. Longer follow-up will be required to see if these second DLI-induced remissions will be durable.
Chromosome 1q has been implicated in the etiology of schizophrenia in several independent studies. However, the peak linkage findings have been dispersed over a large chromosomal region, with negative findings in this region also being reported. Our group has previously observed linkage on chromosome 1q42, maximizing within the DISC1 gene, which has also been implied in the etiology of schizophrenia based on functional studies. In the study presented here, we genotyped 300 polymorphic markers on chromosome 1 using a study sample of 70 families with multiple individuals affected with schizophrenia or related conditions, independent of the study samples in our previous reports. We again found evidence for linkage on 1q42 maximizing within the DISC1 gene (rs1000731, lod=2.70). Further, a haplotype containing the most strongly linked markers showed some evidence of association with the disease. This replicates the previous linkage finding in the same region and constitutes supportive evidence for a susceptibility gene in this region.
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BACKGROUND: to date, only three groups have reported data from large scale genetic association studies of coronary heart disease using a case control design. METHODS AND RESULTS: to extend our initial report of 62 genes, we present data for 210 polymorphisms in 111 candidate genes genotyped in 352 white subjects with familial, premature coronary heart disease (onset age for men, 45; for women, 50) and a random sample of 418 population based whites. Multivariate logistic regression analysis was used to compare the distributions of genotypes between cases and the comparison group while controlling for age, sex, body mass, diabetes, and hypertension. Significant associations were found with polymorphisms in thrombospondin-4 (THBS4), thrombospondin-2 (THBS2) and plasminogen activator inhibitor-2 (PAI2), the strongest being with the A387P variant in THBS4 (p = 0.002). The THBS2 and THBS4 associations have since been replicated. We evaluated polymorphisms in 40 genes previously associated with coronary heart disease and found significant (p<0.05) associations with 10: ACE, APOE, F7, FGB, GP1BA, IL1RN, LRP1, MTHFR, SELP, and THPO. For five of these genes, the polymorphism associated in our study was different from that previously reported, suggesting linkage disequilibrium as an explanation for failure to replicate associations consistently across studies. We found strong linkage disequilibrium between polymorphisms within and between genes, especially on chromosome 1q22-q25, a region containing several candidate genes. CONCLUSIONS: despite known caveats of genetic association studies, they can be an effective means of hypothesis generation and complement classic linkage studies for understanding the genetic basis of coronary heart disease.
A 7-year-old girl with tonsillar infection with antibiotics. Two weeks later, there was a right sided neck lump. Computed tomography scans demonstrated a predominantly hypodense right retropharyngeal area with peripheral enhancement and mass effect. There was intense enhancement within the postero-superior aspect of the lesion which was continuous with the right internal carotid artery. Ultrasound demonstrated tapering of the right internal carotid artery. Magnetic resonance imaging and magnetic resonance arteriography showed a right internal carotid artery pseudoaneurysm. Surgical exploration confirmed the finding. This case highlights an unusual presentation of an internal carotid pseudoaneurysm and how imaging provided the diagnosis.
The marmoset ( Callithrix jacchus) is a small New World monkey that is increasingly being used in a laboratory setting. A previous set of studies has provided a direct comparison between the performance of rats and macaque monkeys on a spatial delayed non-match to sample task in a T-maze (Murray et al. 1989, Experimental Brain Research 74:173-186; Markowska et al. 1989, Experimental Brain Research 74:187-201). In the current experiment we replicated these studies using the marmoset. This allowed for a comparison of the behavioural performance of the marmoset with both rats and macaque monkeys. Marmosets performed well at the task, performing better than macaques, and at a similar level to rats. A closer analysis of the data from the present experiment suggests that marmosets spontaneously alternated in the T-maze, a strategy often adopted by rats, but not by macaques in the T-maze.
The distribution of endemic goitre in England and Wales was compared with the distribution of environmental iodine (atmospheric deposition, soil, surface water). Despite a very clear goitre belt through the west of England and Wales there was no patterning in the environmental iodine distribution. A clear seasonal variation in depositional iodine exists, with an unusually high concentration of iodine in March 1997. The temporal variation in iodine concentration is determined at the monthly and not the annual level. The presence of endemic goitre is no indicator of how iodine is distributed in the environment or vice versa!
Type 2 diabetes mellitus is a heterogeneous inherited disorder characterized by chronic hyperglycemia resulting from pancreatic beta-cell dysfunction and insulin resistance. Although the pathogenic mechanisms are not fully understood, manifestation of the disease most likely requires interaction between both environmental and genetic factors. In the search for such susceptibility genes, we have performed a genomewide scan in 58 multiplex families (comprising 440 individuals, 229 of whom were affected) from the Botnia region in Finland. Initially, linkage between chromosome 12q24 and impaired insulin secretion had been reported, by Mahtani et al., in a subsample of 26 families. In the present study, we extend the initial genomewide scan to include 32 additional families, update the affectation status, and fine map regions of interest, and we try to replicate the initial stratification analysis. In our analysis of all 58 families, we identified suggestive linkage to one region, chromosome 9p13-q21 (nonparametric linkage [NPL] score 3.9; P<.0002). Regions with nominal P values <.05 include chromosomes 2p11 (NPL score 2.0 [P<.03]), 3p24-p22 (NPL score 2.2 [P<.02]), 4q32-q33 (NPL score 2.5 [P<.01]), 12q24 (NPL score 2.1 [P<.03]), 16p12-11 (NPL score 1.7 [P<.05]), and 17p12-p11 (NPL score 1.9 [P<.03]). When chromosome 12q24 was analyzed in only the 32 additional families, a nominal P value <.04 was observed. Together with data from other published genomewide scans, these findings lend support to the hypothesis that regions on chromosome 9p13-q21 and 12q24 may harbor susceptibility genes for type 2 diabetes.
Mutations in the gene encoding for the lysosomal enzyme glucocerebrosidase (GBA) result in Gaucher disease. In this study, seven novel missense mutations in the glucocerebrosidase gene (A136E, H162P, K198E, Y205C, F251L, Q350X and I402F) and a splice site mutation (IVS10+2T-->A) were identified by direct sequencing of three amplified segments of the glucocerebrosidase gene. Five of the novel mutations were found in patients with neuronopathic forms of Gaucher disease, two of which, K198E and F251L, appear to be associated with type 2 Gaucher disease.
The civil claim of occupational rhinitis may be difficult to prove on the balance of probabilities and is the responsibility of the claimant. There are two types of occupational rhinitis, an allergic rhinitis or a rhinitis due to irritation. Occupational rhinitis can be likened to occupational asthma. Particular attention must be paid to the relationship to alleged exposure and symptoms. Irritation causes symptoms during exposure that cease afterwards unless clinically obvious damage has occurred. Tobacco smoke and nicotine may also cause symptoms. A full examination, both externally and internally of the nose, mouth and eyes should be undertaken. The presence of squamous metaplasia is important. The validity of a claimant's symptoms must be checked against the medical records. Details of all occupations, compounds and protection should be noted. Manufacturing data on the compounds should also be obtained. The Health and Safety Executive publish occupational exposure limits for many industrial chemicals. Allergen-specific IgE may be raised when an allergy is considered to cause the occupational rhinitis. Nasal challenge tests have been used in Scandinavia to diagnose allergic occupational rhinitis. The sense of smell should be tested. There are two approaches, detecting threshold or recognition, which is suprathreshold. When present, three degrees of social effect occur: impairment, disability and handicap. The degree depends on the occupation of the individual.
We have previously carried out two genome-wide scans in samples of Finns ascertained for schizophrenia from national epidemiological registers. Here, we report data from a third genome scan in a nationwide Finnish schizophrenia study sample of 238 pedigrees with 591 affected individuals. Of the 238 pedigrees, 53 originated from a small internal isolate (IS) on the eastern border of Finland with a well established genealogical history and a small number of founders, who settled in the community 300 years ago. The total study sample of over 1200 individuals were genotyped, using 315 markers. In addition to the previously identified chromosome 1 locus, two new loci were identified on chromosomes 2q and 5q. The highest LOD scores were found in the IS families with marker D2S427 (Z(max) = 4.43) and in the families originating from the late settlement region with marker D5S414 (Z(max) = 3.56). In addition to 1q, 2q and 5q, some evidence for linkage emerged at 4q, 9q and Xp, the regions also suggested by our previous genome scans, whereas, in the nationwide study sample, the region at 7q failed to show further evidence of linkage. The chromosome 5q finding is of particular interest, since several other studies have also shown evidence for linkage in the vicinity of this locus.
A genomewide screen for quantitative-trait loci (QTLs) that underlie asthma was performed on 533 Chinese families with asthma, by the unified Haseman-Elston method. Nine asthma-related phenotypes were studied, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), airway responsiveness as indicated by methacholine (MTCH)-challenge test, serum total immunoglobulin E (TIgE), serum-specific immunoglobulin E, eosinophil count in peripheral blood, and skin-prick tests with three different allergens (cockroach, Dermatophagoides pteronyssinus, and D. farinae). Our study showed significant linkage between airway responsiveness to MTCH and D2S1780 on chromosome 2 (P<.00002) and provided suggestive evidence (P<.002) for six additional possible QTLs: D10S1435 and D22S685, for FEV1; D16S412, for FVC; D19S433, for airway responsiveness to MTCH; D1S518, for TIgE; and D4S1647, for skin reactivity to cockroach. No significant or suggestive evidence of linkage for the other four traits was found.
We have earlier reported evidence for linkage to two regions on chromosome 1q32--q42 in schizophrenia families collected for two separate studies in Finland. Here we report the results of a fine mapping effort aimed at further definition of the chromosomal region of interest using a large, population-based study sample (221 families, 557 affected individuals). Most affecteds (78%) had a DSM-IV schizophrenia diagnosis and the remaining had schizophrenia spectrum disorders. We genotyped a total of 147 microsatellite markers on a wide 45 cM region of chromosome 1q. The results were analyzed separately for families originating from an internal isolate of Finland and for families from the rest of Finland, as well as for all families jointly. We used traditional two-point linkage analysis, SimWalk2 multipoint analysis and a novel gamete-competition association/linkage method. Evidence for linkage was obtained for one locus in the combined sample (Z(max) = 2.71, D1S2709) and in the nuclear families from outside the internal isolate (Z(max) = 3.21, D1S2709). In the families from the internal isolate the strongest evidence for linkage was obtained with markers located 22 cM centromeric from this marker (Z(max) = 2.30, D1S245). Multipoint analysis also indicated these loci. Some evidence for association with several markers was observed using the gamete-competition method. Interestingly, the strongest evidence for linkage in the combined study sample was obtained for marker D1S2709, which is an intragenic marker of the DISC1 gene, previously suggested as a susceptibility gene for schizophrenia. These results are consistent with the presence of susceptibility gene(s) in this chromosomal region, a result also implied in other recent family studies of schizophrenia.
Genomewide linkage analysis has been extremely successful at identification of the genetic variation underlying single-gene disorders. However, linkage analysis has been less successful for common human diseases and other complex traits in which multiple genetic and environmental factors interact to influence disease risk. We hypothesized that a highly heritable complex trait, in which the contribution of environmental factors was relatively limited, might be more amenable to linkage analysis. We therefore chose to study stature (adult height), for which heritability is approximately 75%-90% (Phillips and Matheny 1990; Carmichael and McGue 1995; Preece 1996; Silventoinen et al. 2000). We reanalyzed genomewide scans from four populations for which genotype and height data were available, using a variance-components method implemented in GENEHUNTER 2.0 (Pratt et al. 2000). The populations consisted of 408 individuals in 58 families from the Botnia region of Finland, 753 individuals in 183 families from other parts of Finland, 746 individuals in 179 families from Southern Sweden, and 420 individuals in 63 families from the Saguenay-Lac-St.-Jean region of Quebec. Four regions showed evidence of linkage to stature: 6q24-25, multipoint LOD score 3.85 at marker D6S1007 in Botnia (genomewide P<.06), 7q31.3-36 (LOD 3.40 at marker D7S2195 in Sweden, P<.02), 12p11.2-q14 (LOD 3.35 at markers D12S10990-D12S398 in Finland, P<.05) and 13q32-33 (LOD 3.56 at markers D13S779-D13S797 in Finland, P<.05). In a companion article (Perola et al. 2001 [in this issue]), strong supporting evidence is obtained for linkage to the region on chromosome 7. These studies suggest that highly heritable complex traits such as stature may be genetically tractable and provide insight into the genetic architecture of complex traits.