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Biomedical subjects

S Forbes

Publications and source records attributed to S Forbes.

At least 19 recordsLinked to original sources

COSMIC 2005.

The Catalogue Of Somatic Mutations In Cancer (COSMIC) database and web site was developed to preserve somatic mutation data and share it with the community. Over the past 25 years, approximately 350 cancer genes have been identified, of which 311 are somatically mutated. COSMIC has been expanded and now holds data previously reported in the scientific literature for 28 known cancer genes. In addition, there is data from the systematic sequencing of 518 protein kinase genes. The total gene count in COSMIC stands at 538; 25 have a mutation frequency above 5% in one or more tumour type, no mutations were found in 333 genes and 180 are rarely mutated with frequencies <5% in any tumour set. The COSMIC web site has been expanded to give more views and summaries of the data and provide faster query routes and downloads. In addition, there is a new section describing mutations found through a screen of known cancer genes in 728 cancer cell lines including the NCI-60 set of cancer cell lines.

Databases, Genetic↗

Distribution of Neoparamoeba sp. in sediments around marine finfish farming sites in Tasmania.

Marine sediment samples collected from various sites at 2 Atlantic salmon farms in Tasmania were analysed for the presence of Neoparamoeba sp., an amoeba associated with amoebic gill disease (AGD) in farmed Atlantic salmon. Environmental variables of the sediment layer at each site, including redox potential and sulphide concentration, were measured and the general biological condition assessed by video observation. Sediments and environmental data were collected on 4 occasions at each site over a 12 mo period. Neoparamoeba sp. was detected in populations of amoebae recovered by culture from all sites and in 50% of all sediment samples taken. There was evidence of a seasonal influence on the presence of the amoeba, but this was different at each farm. No Neoparamoeba sp. was recovered from any sites at Farm 1 during the winter of 2002 whereas at Farm 2 this was the case for the summer of 2003. There appeared to be no relationship between the presence of Neoparamoeba sp., salmon farming activities and environmental parameters.

Animals↗

The COSMIC (Catalogue of Somatic Mutations in Cancer) database and website.

The discovery of mutations in cancer genes has advanced our understanding of cancer. These results are dispersed across the scientific literature and with the availability of the human genome sequence will continue to accrue. The COSMIC (Catalogue of Somatic Mutations in Cancer) database and website have been developed to store somatic mutation data in a single location and display the data and other information related to human cancer. To populate this resource, data has currently been extracted from reports in the scientific literature for somatic mutations in four genes, BRAF, HRAS, KRAS2 and NRAS. At present, the database holds information on 66 634 samples and reports a total of 10 647 mutations. Through the web pages, these data can be queried, displayed as figures or tables and exported in a number of formats. COSMIC is an ongoing project that will continue to curate somatic mutation data and release it through the website.

Databases, Factual↗

Hepatic stem cells: from inside and outside the liver?

The liver is normally proliferatively quiescent, but hepatocyte loss through partial hepatectomy, uncomplicated by virus infection or inflammation, invokes a rapid regenerative response from all cell types in the liver to perfectly restore liver mass. Moreover, hepatocyte transplants in animals have shown that a certain proportion of hepatocytes in foetal and adult liver can clonally expand, suggesting that hepatoblasts/hepatocytes are themselves the functional stem cells of the liver. More severe liver injury can activate a potential stem cell compartment located within the intrahepatic biliary tree, giving rise to cords of bipotential transit amplifying cells (oval cells), that can ultimately differentiate into hepatocytes and biliary epithelial cells. A third population of stem cells with hepatic potential resides in the bone marrow; these haematopoietic stem cells may contribute to the albeit low renewal rate of hepatocytes, but can make a more significant contribution to regeneration under a very strong positive selection pressure. In such instances, cell fusion rather than transdifferentiation appears to be the underlying mechanism by which the haematopoietic genome becomes reprogrammed.

Animals↗

An assessment of mother-to-child HIV transmission prevention in 16 pilot antenatal clinics in Jamaica.

OBJECTIVES: This study aims to determine the number and age distribution of pregnant women testing positive for HIV at 16 selected clinics in Jamaica between 2001 and 2002; the utilization of therapeutic interventions to minimize the risk of mother-to-child transmission (MTCT) and the current status of the HIV-exposed infants and, finally, the number of children who received testing for detection of HIV and to calculate the incidence of MTCT in these children. METHODS: A retrospective study was carried out at sixteen pilot clinic sites by examining the patient records for all confirmed HIV-positive pregnant mothers and the resultant infants at these facilities for the period January 2001 to December 2002. RESULTS: One hundred and twenty-three of 8116 pregnant women newly tested positive during the period January 2001 to December 2002; however, 176 HIV+ women delivered. Fifty-three (30%) knew their HIV status prior to participating in the programme. Sixty-two (1.4%) and 61 (1.6%) tested positive in 2001 and 2002, respectively. One hundred and ten (77%) and 113 (83%) mothers and infants, respectively, received ARV therapy, (92% - nevirapine, 8% - zidovudine). Twenty-three per cent of pregnant women received no ARV Forty-four (25.0%) of the 176 infants had a documented ELISA HIV test before eighteen months of age, none had a PCR test. The health status of 40 (23%) of these children was known: 30 (75%) were alive and well, five of whom did not receive any ARV, one (2.5%) was alive and ill and nine (22.5%) were reported dead, five of whom received ARV; 28.6% of infants who did not receive ARV were reported as either dead or ill compared to 13.8% of those receiving ARV CONCLUSION: Though the majority of pregnant women discovered their HIV status during pregnancy, a significant number got pregnant knowing that they were HIV+. The majority of mothers and infants received ARV but the follow-up and testing of infants was limited. Nevirapine is clearly protective in the prevention of MTCT of HIV and should be made universally accessible. All infants delivered to HIV+ mothers should be identified and tested for HIV.

AIDS Serodiagnosis↗

Microarray gene expression profiling of angiogenesis inhibitors using the rat aortic ring assay.

The rat aortic ring assay has been previously described as a useful ex vivo model for analyzing the biological activity of various inhibitors of angiogenesis. Rat aortic rings are exposed to antiangiogenic agents for a five-day incubation period. Then, the degree of microvessel outgrowth from the rings is analyzed and quantified. In contrast to most in vitro angiogenesis assays, the rat aortic ring model provides a unique microenvironment to evaluate the interaction of various cell types and biological factors for their influence on angiogenesis. Microarray analysis is an accepted method for the evaluation of gene expression profiles and can be used to better understand changes in gene expression that occur when rat aortic rings are exposed to a particular biological agent. Here we describe a method of using microarray technology to evaluate the modulation of gene expression in angiogenesis using the rat aortic ring assay.

Angiogenesis Inhibitors↗

Integrated control of appetite and fat metabolism by the leptin-proopiomelanocortin pathway.

Leptin deficiency results in a complex obesity phenotype comprising both hyperphagia and lowered metabolism. The hyperphagia results, at least in part, from the absence of induction by leptin of melanocyte stimulating hormone (MSH) secretion in the hypothalamus; the MSH normally then binds to melanocortin-4 receptor expressing neurons and inhibits food intake. The basis for the reduced metabolic rate has been unknown. Here we show that leptin administered to leptin-deficient (ob/ob) mice results in a large increase in peripheral MSH levels; further, peripheral administration of an MSH analogue results in a reversal of their abnormally low metabolic rate, in an acceleration of weight loss during a fast, in partial restoration of thermoregulation in a cold challenge, and in inducing serum free fatty acid levels. These results support an important peripheral role for MSH in the integration of metabolism with appetite in response to perceived fat stores indicated by leptin levels.

Animals↗

The need to revise assumptions about the end of life: implications for social work practice.

During the 20th century the experience of dying changed dramatically. At the beginning of the 1900s, dying and death were integral parts of the life experience of most people at any age. Many deaths occurred at home following a short course of illness largely unaffected by the limited medical care available. At the beginning of the 21st century, in many cases, the process of dying has become invisible. Today, most deaths occur in old age. Social workers have a key role as "context interpreters" in helping people at the end of life and their families understand the natural course of the illness, the process of dying, and the advantages and drawbacks of medical interventions. An expanded role for social workers in helping people comprehend the medical and social contexts within which they face end-of-life decisions is discussed.

Advance Directives↗

Characterization of clustered MHC-linked olfactory receptor genes in human and mouse.

Olfactory receptor (OR) loci frequently cluster and are present on most human chromosomes. They are members of the seven transmembrane receptor (7-TM) superfamily and, as such, are part of one of the largest mammalian multigene families, with an estimated copy number of up to 1000 ORs per haploid genome. As their name implies, ORs are known to be involved in the perception of odors and possibly also in other, nonolfaction-related, functions. Here, we report the characterization of ORs that are part of the MHC-linked OR clusters in human and mouse (partial sequence only). These clusters are of particular interest because of their possible involvement in olfaction-driven mate selection. In total, we describe 50 novel OR loci (36 human, 14 murine), making the human MHC-linked cluster the largest sequenced OR cluster in any organism so far. Comparative and phylogenetic analyses confirm the cluster to be MHC-linked but divergent in both species and allow the identification of at least one ortholog that will be useful for future regulatory and functional studies. Quantitative feature analysis shows clear evidence of duplications of blocks of OR genes and reveals the entire cluster to have a genomic environment that is very different from its neighboring regions. Based on in silico transcript analysis, we also present evidence of extensive long-distance splicing in the 5'-untranslated regions and, for the first time, of alternative splicing within the single coding exon of ORs. Taken together with our previous finding that ORs are also polymorphic, the presented data indicate that the expression, function, and evolution of these interesting genes might be more complex than previously thought.

Amino Acid Sequence↗

This is Heaven's waiting room: end of life in one nursing home.

The purpose of this study was to describe the end of life in one midwestern nursing home from the perspective of residents who are chronically ill and declining, their family caregivers, and staff. Qualitative methods, including formal and informal interviews, participant observation, and health record abstraction, were used to describe the end of life for 13 nursing home residents. One dominating pattern, conflict, and five themes (i.e., communication, quality of life, staff education, teamwork, work environment) emerged as factors that influenced end-of-life care. The results of this study illustrate where and how problems within the nursing home industry, the participating nursing home, and between staff and residents influence and challenge care provided to dying residents.

Aged↗

End-of-life care in the intensive care unit: a challenge for nurses.

Results from several research studies combined with increasing public tensions surrounding physician-assisted suicide have fueled a growing awareness of the inadequacies of end-of-life care. Investigators also suggest that intensive care unit nurses have a limited role in end-of-life decision making and care planning. This article explores cultural issues influencing end-of-life care in intensive care units, explores factors surrounding the limited involvement of critical care nurses in end-of-life decision making and care planning, and offers recommendations for changing nursing practice. Because improving end-of-life care will require cultural changes, an understanding of the cultural issues involved is needed. Recommendations for changing nursing practice include a model of end-of-life care that incorporates the goals of both cure and comfort care, as well as a shared decision-making process. Nurses are essential to improving end-of-life care in today's intensive care units.

Aged↗

Polymorphisms in olfactory receptor genes: a cautionary note.

The hundreds of human olfactory receptor (OR) genes are organized into clusters occurring on nearly every chromosome. Although their sequences are not always closely related, they share stretches of considerable similarity, both at the amino acid and nucleotide levels. We demonstrate here that an HLA complex-linked OR sequence, FAT11, for which recently a number of alleles have been claimed within the Hutterites, contains sequences derived from two closely related, linked OR genes, hs6M1-12 and hs6M1-16. Instead of indicating a difference between alleles of a given locus, two of the polymorphisms described for FAT11 (at amino acids 48 and 220 of the deduced protein sequence, respectively) may in fact reflect distinct sequences of hs6M1-12 and a further, closely related HLA-linked OR locus, hs6M1-13P. As a consequence, recombination rates in Hutterites in the region telomeric of HLA-G may have to be reconsidered.

Amino Acid Substitution↗

Monosaccharide/proton symporter AtSTP1 plays a major role in uptake and response of Arabidopsis seeds and seedlings to sugars.

The aim of this study was to investigate the in vivo properties and function of the high-affinity monosaccharide/proton symporter AtSTP1 of Arabidopsis. We isolated an Atstp1 knock-out mutant and found that this plant grows and develops normally. The AtSTP1 gene is expressed in germinating seeds and seedlings, with AtSTP1 activity found mainly in the seedling root. The rate of uptake of [(14)C]-3-O-methylglucose and [(14)C]-D-glucose is 60% less in Atstp1 seedlings than in the wild type, showing that AtSTP1 is the major monosaccharide transporter in Arabidopsis seedlings. Transport of D-galactose and D-mannose is also up to 60% less in Atstp1 seedlings compared to wild type, but transport of D-fructose, L-arabinose and sucrose is not reduced. Germination of Atstp1 seed shows reduced sensitivity to D-mannose, demonstrating that AtSTP1 is active before germination. Atstp1 seedlings grow effectively on concentrations of D-galactose that inhibit wild-type growth, even at up to 100 mM D-galactose, indicating that active transport by AtSTP1 plays a major role at very high concentrations of exogenous sugar. These findings provide insight into the physiological function of AtSTP1 and clearly establish its importance in the uptake of extracellular sugars by the embryo and in seedlings.

Arabidopsis↗

End-of-life decision making for nursing home residents with dementia.

PURPOSE: To describe families' decision-making processes, both cognitive and affective, regarding end-of-life treatments for nursing home residents with moderately severe to very severe dementia. DESIGN: Naturalistic inquiry provided the framework for this descriptive, qualitative study. METHODS: Four focus groups were conducted in selected nursing homes, in the central part of the United States for a qualitative study. Twenty-eight family members of residents with moderately severe to severe dementia shared their decision-making experiences. Open-ended questions were asked in each focus group. Data were analyzed using content analysis. FINDINGS: Five themes were identified that describe the context of decision making: emotional effect, insult-to-life story, two faces of death, values and goals regarding end-of-life treatments, and the unrecognized trajectory of dying. Family members made decisions in an emotional climate of overwhelming burden and guilt, because their loved one's life had been robbed of personhood, the changes associated with decline from a dementia-related illness were unrecognized as part of a trajectory of dying, death was both a tragedy and a blessing. CONCLUSIONS: Family members had poignant, unresolved emotional needs stemming from their loved one's illness and nursing home placement. Participants were unprepared to make end-of-life treatment decisions and lacked the informational and emotional support of a consistent provider to help with decisions. Family members need assistance in processing difficult and painful emotions, understanding the trajectory of disease, what decisions might impede a natural death, and comfort or palliative care options.

Aged↗

Predictors of death and vascular events in the elderly : the Perth Community Stroke Study.

BACKGROUND AND PURPOSE: The goal of the present study was to identify risk factors for vascular disease in the elderly. METHODS: We conducted a prospective study of control subjects from a population-based study of stroke in Perth, Western Australia, that was completed in 1989 to 1990 and used record linkage and a survey of survivors to identify deaths and nonfatal vascular events. Data validated through reference to medical records were analyzed with the use of Cox proportional hazards models. RESULTS: Follow-up for the 931 subjects was 88% complete. By June 24, 1994, 198 (24%) of the subjects had died (96 from vascular disease), and there had been 45 nonfatal strokes or myocardial infarctions. The hazard ratio for diabetes exceeded 2.0 for all end points, whereas the consumption of meat >4 times weekly was associated with a reduction in risk of </=30%. In most models, female sex and consumption of alcohol were associated with reduced risks, whereas previous myocardial infarction was linked to an increase in risk. CONCLUSIONS: There are only limited associations between lifestyle and major vascular illness in old age. Effective health promotion activities in early and middle life may be the key to a longer and healthier old age.

Alcohol Drinking↗

Five-year survival after first-ever stroke and related prognostic factors in the Perth Community Stroke Study.

BACKGROUND AND PURPOSE: Few community-based studies have examined the long-term survival and prognostic factors for death within 5 years after an acute first-ever stroke. This study aimed to determine the absolute and relative survival and the independent baseline prognostic factors for death over the next 5 years among all individuals and among 30-day survivors after a first-ever stroke in a population of Perth, Western Australia. METHODS: Between February 1989 and August 1990, all individuals with a suspected acute stroke or transient ischemic attack of the brain who were resident in a geographically defined region of Perth, Western Australia, with a population of 138 708 people, were registered prospectively and assessed according to standardized diagnostic criteria. Patients were followed up prospectively at 4 months, 12 months, and 5 years after the index event. RESULTS: Three hundred seventy patients with first-ever stroke were registered, and 362 (98%) were followed up at 5 years, by which time 210 (58%) had died. In the first year after stroke the risk of death was 36.5% (95% CI, 31.5% to 41.4%), which was 10-fold (95% CI, 8.3% to 11.7%) higher than that expected among the general population of the same age and sex. The most common cause of death was the index stroke (64%). Between 1 and 5 years after stroke, the annual risk of death was approximately 10% per year, which was approximately 2-fold greater than expected, and the most common cause of death was cardiovascular disease (41%). The independent baseline factors among 30-day survivors that predicted death over 5 years were intermittent claudication (hazard ratio [HR], 1.9; 95% CI, 1.2 to 2.9), urinary incontinence (HR, 2.0; 95% CI, 1. 3 to 3.0), previous transient ischemic attack (HR, 2.4; 95% CI, 1.4 to 4.1), and prestroke Barthel Index <20/20 (HR, 2.0; 95% CI, 1.2 to 3.2). CONCLUSIONS: One-year survivors of first-ever stroke continue to die over the next 4 years at a rate of approximately 10% per year, which is twice the rate expected among the general population of the same age and sex. The most common cause of death is cardiovascular disease. Long-term survival after stroke may be improved by early, active, and sustained implementation of effective strategies for preventing subsequent cardiovascular events.

Age Factors↗