Publications by authors named "Frodsham A"

Purpose: To report initial experience using N-butyl cyanoacrylate (n-BCA) to control lower gastrointestinal hemorrhage (LGIH).

Materials And Methods: From May 2005 to March 2009, 14 patients with LGIH underwent mesenteric angiography and transcatheter arterial embolization using n-BCA. Candidacy was primarily based on the patient's hemodynamic stability and the risk for future LGIH, determined by the presence of at least one of the following risk factors: more than one arterial feeder supplying the bleeding vessel, underlying coagulopathy, or need to resume anticoagulation after embolization.

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Studies of animal populations suggest that low genetic heterozygosity is an important risk factor for infection by a diverse range of pathogens, but relatively little research has looked to see whether similar patterns exist in humans. We have used microsatellite genome screen data for tuberculosis (TB), hepatitis and leprosy to test the hypothesis that inbreeding depression increases risk of infection. Our results indicate that inbred individuals are more common among our infected cases for TB and hepatitis, but only in populations where consanguineous marriages are common.

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Multiple genes have been studied for potential associations with lung cancer. The gene most frequently associated with increased risk has been glutathione S-transferase M1 (GSTM1). The glutathione S-transferase enzyme family is known to catalyze detoxification of electrophilic compounds, including carcinogens, therapeutic drugs, environmental toxins, and products of oxidative stress.

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Background: Two receptor chains, IL-10RA and IL-10RB, are known to mediate the functions of interleukin-10 (IL-10), which has been shown to be involved in the progression of persistent hepatitis C virus (HCV) infection. Little information is available on the role of host genetic variation in IL-10 receptor genes and outcome of HCV infection. IL-22, an IL-10 homologue, shares the IL-10RB receptor chain with IL-10 and has antiviral properties.

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Background: With the advent of high throughput genotyping technology and the information available via projects such as the human genome sequencing and the HapMap project, more and more data relevant to the study of genetics and disease risk will be produced. Systematic reviews and meta-analyses of human genome epidemiology studies rely on the ability to identify relevant studies and to obtain suitable data from these studies. A first port of call for most such reviews is a search of MEDLINE.

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Rationale: Increasing evidence supports a key role for the transcription factor nuclear factor (NF)-kappaB in the host response to pneumococcal infection. Control of NF-kappaB activity is achieved through interactions with the IkappaB family of inhibitors, encoded by the genes NFKBIA, NFKBIB, and NFKBIE. Rare NFKBIA mutations cause immunodeficiency with severe bacterial infection, raising the possibility that common IkappaB gene polymorphisms confer susceptibility to common bacterial disease.

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Toll-like receptors (TLRs) and members of their signaling pathway are important in the initiation of the innate immune response to a wide variety of pathogens. The adaptor protein Mal (also known as TIRAP), encoded by TIRAP (MIM 606252), mediates downstream signaling of TLR2 and TLR4 (refs. 4-6).

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Persistent hepatitis B virus infection is a major risk factor for hepatocellular carcinoma, the most frequent cancer in some developing countries. Up to 95% of those infected at birth and 15% of those infected after the neonatal period fail to clear hepatitis B virus, together resulting in approximately 350 million persistent carriers worldwide. Via a whole genome scan in Gambian families, we have identified a major susceptibility locus as a cluster of class II cytokine receptor genes on chromosome 21q22.

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Hepatitis B Virus (HBV) infection can result in numerous different clinical outcomes. A complex combination of environment, and viral and host genetic factors play a critical role in determining both susceptibility to HBV persistence and the course of infection. Evidence is presented that suggests that host genetic factors play an important role in determining the outcome of HBV infection.

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Differences in allelic associations between populations continue to cause difficulties in the mapping and identification of susceptibility genes for complex polygenic diseases. Although well recognized, the basis of such interpopulation differences is poorly understood. We present an example of an inverse allelic association of an immune response genotype to an infectious disease in two neighboring West African populations.

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Infectious diseases represent a major health problem worldwide, both in terms of morbidity and mortality. A complex combination of environmental, pathogen and host genetic factors plays a role in determining both susceptibility to particular microbes and the course of infection. Numerous studies have now mapped and identified relevant genes using a variety of both family-based and population-based approaches.

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Inducible nitric oxide synthase (iNOS) is an important molecule involved in the host defense against infectious agents. iNOS is encoded by the NOS2A gene and well-defined haplotypes exist with respect to this gene. We examined whether these haplotypes were associated with the outcome of hepatitis C virus (HCV) infection in 619 Caucasian patients from seven European liver centres.

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The effect of host genetic variation on the outcome of hepatitis C virus (HCV) infection and its treatment is poorly understood. The chemokine receptors CCR5, CCR2, and CCR3 and their ligands, RANTES, MCP-1, MCP-2, and MIP-1alpha, are involved in the immune responses and the selective recruitment of lymphocytes to the liver in HCV infection. We studied 20 polymorphisms within these genes and investigated their association with persistent carriage of HCV, severity of liver disease, hepatic inflammation, and response to treatment in a large European cohort.

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Interferon stimulates the expression of a number of genes encoding enzymes with antiviral activities, including myxovirus resistance-1 (MxA), 2-5-oligoadenylate synthetase 1 (OAS-1) and double-stranded RNA-dependent protein kinase (PKR). We examined whether polymorphisms in these genes influenced the outcome of hepatitis C virus (HCV) infection. We observed a lower frequency of the GG genotype at position -88 in the MxA gene promoter in self-limiting HCV infection (OR=0.

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The natural outcome and response to treatment in hepatitis C virus (HCV) infection varies between individuals. Whereas some variation may be attributable to viral and environmental variables, it is probable that host genetic background also plays a significant role. Interleukin (IL)-10 has a key function in the regulation of cellular immune responses and in the suppression of pro-inflammatory cytokine secretion.

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Background: The rate of progression to cirrhosis varies among individuals chronically infected with the hepatitis C virus (HCV). Coagulation pathway activation in models of hepatic fibrosis suggests variation in coagulation pathway components may influence the rate of fibrosis. We hypothesised that polymorphisms of the coagulation factors II and V affect the rate of progression to cirrhosis in HCV infected subjects.

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The chromosome 21q22.11 cytokine receptor cluster contains four genes that encode subunits of the receptors for the cytokines interleukin-10 and interferon-alpha, -beta and -gamma that may have a role in malaria pathogenesis. A total of 15 polymorphic markers located within these genes were initially genotyped in 190 controls and 190 severe malaria cases from The Gambia.

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The low-density lipoprotein receptor (LDLR) has been proposed to promote hepatitis C virus endocytosis and the cell membrane protein CD81 may also promote HCV host cell entry. The CD81 gene was sequenced to screen for novel polymorphisms, but no SNPs were identified. Polymorphisms within the LDLR gene are associated with the pathogenesis of familial hypercholesterolemia, atherosclerosis and obesity.

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Microsatellites are now used ubiquitously as genetic markers. One important application is to the assessment of population subdivision and phylogenetic relatedness. Such applications require a method of estimation of genetic distance.

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Host genetic factors including major histocompatibility complex (MHC) polymorphisms influence both susceptibility to leprosy per se and also to leprosy type. Non-MHC genes may play an important role, but such genes remain undefined. The influence of two non-MHC candidate genes was assessed in a case-control study of Bengali leprosy patients from Calcutta.

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Psoriasis is a common chronic inflammatory disorder of the skin. To further understand the pathogenesis of psoriasis we have chosen to investigate the molecular genetic basis of the disorder. We have used a two-stage approach to search the human genome for the location of genes conferring susceptibility to psoriasis, using a total of 106 affected sibling pairs identified from 68 independent families.

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