141 resultados para Genomics and genetics
Resumo:
Animal venom components are of considerable interest to researchers across a wide variety of disciplines, including molecular biology, biochemistry, medicine, and evolutionary genetics. The three-finger family of snake venom peptides is a particularly interesting and biochemically complex group of venom peptides, because they are encoded by a large multigene family and display a diverse array of functional activities. In addition, understanding how this complex and highly varied multigene family evolved is an interesting question to researchers investigating the biochemical diversity of these peptides and their impact on human health. Therefore, the purpose of our study was to investigate the long-term evolutionary patterns exhibited by these snake venom toxins to understand the mechanisms by which they diversified into a large, biochemically diverse, multigene family. Our results show a much greater diversity of family members than was previously known, including a number of subfamilies that did not fall within any previously identified groups with characterized activities. In addition, we found that the long-term evolutionary processes that gave rise to the diversity of three-finger toxins are consistent with the birth-and-death model of multigene family evolution. It is anticipated that this three-finger toxin toolkit will prove to be useful in providing a clearer picture of the diversity of investigational ligands or potential therapeutics available within this important family.
Resumo:
EDD (E3 isolated by differential display), located at chromosome 8q22.3, is the human orthologue of the Drosophila melanogaster tumour suppressor gene 'hyperplastic discs' and encodes a HECT domain E3 ubiquitin protein-ligase. To investigate the possible involvement of EDD in human cancer, several cancers from diverse tissue sites were analysed for allelic gain or loss (allelic imbalance, AI) at the EDD locus using an EDD-specific microsatellite, CEDD, and other polymorphic microsatellites mapped in the vicinity of the 8q22.3 locus. Of 143 cancers studied, 38 had AI at CEDD (42% of 90 informative cases). In 14 of these cases, discrete regions of imbalance encompassing 8q22.3 were present, while the remainder had more extensive 8q aberrations. AI of CEDD was most frequent in ovarian cancer (22/47 informative cases, 47%), particularly in the serous subtype (16/22, 73%), but was rare in benign and borderline ovarian tumours. AI was also common in breast cancer (31%), hepatocellular carcinoma (46%), squamous cell carcinoma of the tongue (50%) and metastatic melanoma (18%). AI is likely to represent amplification of the EDD gene locus rather than loss of heterozygosity, as quantitative RT-PCR and immunohistochemistry showed that EDD mRNA and protein are frequently overexpressed in breast and ovarian cancers, while among breast cancer cell lines EDD overexpression and increased gene copy number were correlated. These results demonstrate that AI at the EDD locus is common in a diversity of carcinomas and that the EDD gene is frequently overexpressed in breast and ovarian cancer, implying a potential role in cancer progression.
Resumo:
Aim: To test the acceptability of a comprehensive health assessment program (CHAP) in adults with an intellectual disability (ID). Method: We interviewed adults with ID, their general practitioners (GPs) and caregivers (healthcare triad), before and after the intervention period as part of a clustered randomised controlled trial to test the use of the CHAP tool in adults with ID. A content and thematic analysis of these interviews will be presented. Results: We found adults with ID were unable to recall the health assessment consultation or differentiate this consultation from the usual contact with their GP. GPs and residential staff where largely supportive of the process and considered it did improve the care they could provide to AWID. They also considered that the intervention helped other members of the healthcare triad. Conclusions: The CHAP was found to be acceptable to caregivers and GPs however further work is needed to ascertain the views of adults with ID.
Resumo:
Aim: To determine acceptability of a health advocacy intervention, the Ask Diary and the comprehensive health assessment program (CHAP). Method: We performed a two by two designed randomised controlled trial of the Ask Diary and the CHAP tool in adults with intellectual disability. Results of interviews of self-advocates and caregiver advocates, both families and paid carers, will be presented. Results: The interviews found strong support for the Ask Diary and the CHAP tool among selfadvocates and family caregivers. There was clear indication that the Ask Diary improved advocacy, aided in the organisation of health matters and was easy to use. It was reported that the health assessment resulted in benefits for the person’s health and high acceptability by carers. There was less support for the interventions where the person was supported through government services. Conclusions: Self-advocates and family caregivers welcome and use a personalised health advocacy diary and also a health assessment. However paid carers used the diary less but were supportive of the health assessment.
Resumo:
Background: Familial partial epilepsy with variable foci (FPEVF) is an autosomal dominant syndrome characterized by partial seizures originating from different brain regions in different family members in the absence of detectable structural abnormalities. A gene for FPEVF was mapped to chromosome 22q12 in two distantly related French-Canadian families. Methods: We describe the clinical features and performed a linkage analysis in a Spanish kindred and in a third French-Canadian family distantly related to the original pedigrees. Results: Onset of seizures was typically in middle childhood, and attacks were usually easy to control. Seizure semiology varied among family members but was constant for each individual. In some, a pattern of nocturnal frontal lobe seizures led to consideration of the diagnosis of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). The Spanish family was mapped to chromosome 22q (multipoint lod score, 3.4), and the new French-Canadian family had a multipoint lod score of 2.97 and shared the haplotype of the original French-Canadian families. Conclusions: Identification of the various forms of familial partial epilepsy is challenging, particularly in small families, in which insufficient individuals exist to identify a specific pattern. We provide clinical guidelines for this task, which will eventually be supplanted by specific molecular diagnosis. We confirmed linkage of FPEVF to chromosome 22q 12 and redefined the region to a 5.2-Mb segment of DNA.
Resumo:
Ozone is a major air pollutant with adverse health effects which exhibit marked inter-individual variability. In mice, regions of genetic linkage with ozone-induced lung injury include the tumor necrosis factor-alpha (TNF), lymphotoxin-alpha (LTA), Toll-like receptor 4 (TLR4), superoxide dismutase (SOD2), and glutathione peroxidase (GPX1) genes. We genotyped polymorphisms in these genes in 51 individuals who had undergone ozone challenge. Mean change in FEV1 with ozone challenge, as a percentage of baseline, was -3% in TNF -308G/A or A/A individuals, compared with -9% in G/G individuals (p = 0.024). When considering TNF haplotypes, the smallest change in FEV1 with ozone exposure was associated with the TNF haplotype comprising LTA +252G/TNF -1031T/TNF -308A/TNF -238G. This association remained statistically significant after correction for age, sex, disease, and ozone concentration (p = 0.047). SOD2 or GPX1 genotypes were not associated with lung function, and the TLR4 polymorphism was too infrequent to analyze. The results of this study support TNF as a genetic factor for susceptibility to ozone-induced changes in lung function in humans, and has potential implications for stratifying health risks of air pollution.
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Numerous studies have reported that females benefit from mating with multiple males (polyandry) by minimizing the probability of fertilization by genetically incompatible sperm. Few, however, have directly attributed variation in female reproductive success to the fertilizing capacity of sperm. In this study we report on two experiments that investigated the benefits of polyandry and the interacting effects of males and females at fertilization in the free-spawning Australian sea urchin Heliocidaris erythrogramma. In the first experiment we used a paired (split clutch) experimental design and compared fertilization rates within female egg clutches under polyandry (eggs exposed to the sperm from two males simultaneously) and monandry (eggs from the same female exposed to sperm from each of the same two males separately). Our analysis revealed a significant fertilization benefit of polyandry and strong interacting effects of males and females at fertilization. Further analysis of these data strongly suggested that the higher rates of fertilization in the polyandry treatment were due to an overrepresentation of fertilizations due to the most compatible male. To further explore the interacting effects of males and females at fertilization we performed a second factorial experiment in which four mates were crossed with two females (in all eight combinations). In addition to confirming that fertilization success is influenced by male X female interactions, this latter experiment revealed that both sexes contributed significant variance to the observed patterns of fertilization. Taken together, these findings highlight the importance of male X female interactions at fertilization and suggest that polyandry will enable females to reduce the cost of fertilization by incompatible gametes.