48 research outputs found
X-linked myotubular myopathy associated with an MTM1 variant in a Maine coon cat.
OBJECTIVE: Describe the clinical course and diagnostic and genetic findings in a cat with X-linked myotubular myopathy. CASE SUMMARY: A 7-month-old male Maine coon was evaluated for progressively worsening gait abnormalities and generalized weakness. Neurolocalization was to the neuromuscular system. Genetic testing for spinal muscular atrophy (LIX1) was negative. Given the progressive nature and suspected poor long-term prognosis, the owners elected euthanasia. Histopathology of skeletal muscle obtained post-mortem disclosed numerous rounded atrophic or hypotrophic fibers with internal nuclei or central basophilic staining. Using oxidative reactions mediated by cytochrome C oxidase and succinic dehydrogenase, scattered myofibers were observed to have central dark staining structures and a ring-like appearance. Given the cats age and clinical history, a congenital myopathy was considered most likely, with the central nuclei and ring-like changes consistent with either centronuclear or myotubular myopathy. Whole genome sequencing identified an underlying missense variant in myotubularin 1 (MTM1), a known candidate gene for X-linked myotubular myopathy. NEW OR UNIQUE INFORMATION PROVIDED: This case is the first report of X-linked myotubular myopathy in a cat with an MTM1 missense mutation. Maine coon cat breeders may consider screening for this variant to prevent production of affected cats and to eradicate the variant from the breeding population
The effect of age and unilateral leg immobilisation for 2 weeks on substrate ulilisation during moderate-intensity exercise in human skeletal muscle
Age and inactivity have been associated with intramuscular triglyceride (IMTG) accumulation. Here, we attempt to disentangle these factors by studying the effect of 2 weeks of unilateral leg immobilization on substrate utilization across the legs during moderate-intensity exercise in young (n = 17; 23 ± 1 years old) and older men (n = 15; 68 ± 1 years old), while the contralateral leg served as the control. After immobilization, the participants performed two-legged isolated knee-extensor exercise at 20±1W(_50% maximalwork capacity) for 45 min with catheters inserted in the brachial artery and both femoral veins.Biopsy samples obtained from vastus lateralis muscles of both legs before and after exercise were used for analysis of substrates, protein content and enzyme activities. During exercise, leg substrate utilization (respiratoryquotient) did not differ between groups or legs. Leg fatty acid uptake was greater in older than in young men, and although young men demonstrated net leg glycerol release during exercise, older men showed net glycerol uptake. At baseline, IMTG, muscle pyruvate dehydrogenase complex activity and the protein content of adipose triglyceride lipase, acetyl-CoA carboxylase 2 and AMP-activated protein kinase (AMPK)γ3 were higher in young than in older men. Furthermore, adipose triglyceride lipase, plasma membrane-associated fatty acid binding protein and AMPKγ3 subunit protein contents were lower and IMTG was higher in the immobilized than the contralateral leg in young and older men. Thus, immobilization and age did not affect substrate choice (respiratory quotient) during moderate exercise, but the whole-leg and molecular differences in fatty acid mobilization could explain the age- and immobilization-induced IMTG accumulation
Correlates of tobacco cessation counseling among Hispanic physicians in the US: a cross-sectional survey study.
BACKGROUND: Physician advice is an important motivator for attempting to stop smoking. However, physicians\u27 lack of intervention with smokers has only modestly improved in the last decade. Although the literature includes extensive research in the area of the smoking intervention practices of clinicians, few studies have focused on Hispanic physicians. The purpose of this study was to explore the correlates of tobacco cessation counseling practices among Hispanic physicians in the US.
METHODS: Data were collected through a validated survey instrument among a cross-sectional sample of self-reported Hispanic physicians practicing in New Mexico, and who were members of the New Mexico Hispanic Medical Society in the year 2001. Domains of interest included counseling practices, self-efficacy, attitudes/responsibility, and knowledge/skills. Returned surveys were analyzed to obtain frequencies and descriptive statistics for each survey item. Other analyses included: bivariate Pearson\u27s correlation, factorial ANOVAs, and multiple linear regressions.
RESULTS: Respondents (n = 45) reported a low level of compliance with tobacco control guidelines and recommendations. Results indicate that physicians\u27 familiarity with standard cessation protocols has a significant effect on their tobacco-related practices (r = .35, variance shared = 12%). Self-efficacy and gender were both significantly correlated to tobacco related practices (r = .42, variance shared = 17%). A significant correlation was also found between self-efficacy and knowledge/skills (r = .60, variance shared = 36%). Attitudes/responsibility was not significantly correlated with any of the other measures.
CONCLUSION: More resources should be dedicated to training Hispanic physicians in tobacco intervention. Training may facilitate practice by increasing knowledge, developing skills and, ultimately, enhancing feelings of self-efficacy
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Thigh-length compression stockings and DVT after stroke
Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease
Exome capture from saliva produces high quality genomic and metagenomic data
CITATION: Kidd, J. M. et al. 2014. Exome capture from saliva produces high quality genomic and metagenomic data. BMC Genomics, 15:262, doi:10.1186/1471-2164-15-262.The original publication is available at http://www.biomedcentral.com/1471-2164/15/262Background
Targeted capture of genomic regions reduces sequencing cost while generating higher coverage by allowing biomedical researchers to focus on specific loci of interest, such as exons. Targeted capture also has the potential to facilitate the generation of genomic data from DNA collected via saliva or buccal cells. DNA samples derived from these cell types tend to have a lower human DNA yield, may be degraded from age and/or have contamination from bacteria or other ambient oral microbiota. However, thousands of samples have been previously collected from these cell types, and saliva collection has the advantage that it is a non-invasive and appropriate for a wide variety of research.
Results
We demonstrate successful enrichment and sequencing of 15 South African KhoeSan exomes and 2 full genomes with samples initially derived from saliva. The expanded exome dataset enables us to characterize genetic diversity free from ascertainment bias for multiple KhoeSan populations, including new exome data from six HGDP Namibian San, revealing substantial population structure across the Kalahari Desert region. Additionally, we discover and independently verify thirty-one previously unknown KIR alleles using methods we developed to accurately map and call the highly polymorphic HLA and KIR loci from exome capture data. Finally, we show that exome capture of saliva-derived DNA yields sufficient non-human sequences to characterize oral microbial communities, including detection of bacteria linked to oral disease (e.g. Prevotella melaninogenica). For comparison, two samples were sequenced using standard full genome library preparation without exome capture and we found no systematic bias of metagenomic information between exome-captured and non-captured data.
Conclusions
DNA from human saliva samples, collected and extracted using standard procedures, can be used to successfully sequence high quality human exomes, and metagenomic data can be derived from non-human reads. We find that individuals from the Kalahari carry a higher oral pathogenic microbial load than samples surveyed in the Human Microbiome Project. Additionally, rare variants present in the exomes suggest strong population structure across different KhoeSan populations.Publishers' Versio
Recommended from our members
SharptonThomasMicrobiologyExomeCaptureSaliva_SupplementaryMaterial.pdf
BACKGROUND: Targeted capture of genomic regions reduces sequencing cost while generating higher coverage by
allowing biomedical researchers to focus on specific loci of interest, such as exons. Targeted capture also has the
potential to facilitate the generation of genomic data from DNA collected via saliva or buccal cells. DNA samples
derived from these cell types tend to have a lower human DNA yield, may be degraded from age and/or have
contamination from bacteria or other ambient oral microbiota. However, thousands of samples have been previously
collected from these cell types, and saliva collection has the advantage that it is a non-invasive and appropriate for a
wide variety of research.
RESULTS: We demonstrate successful enrichment and sequencing of 15 South African KhoeSan exomes and 2 full
genomes with samples initially derived from saliva. The expanded exome dataset enables us to characterize genetic
diversity free from ascertainment bias for multiple KhoeSan populations, including new exome data from six HGDP
Namibian San, revealing substantial population structure across the Kalahari Desert region. Additionally, we discover
and independently verify thirty-one previously unknown KIR alleles using methods we developed to accurately map
and call the highly polymorphic HLA and KIR loci from exome capture data. Finally, we show that exome capture of
saliva-derived DNA yields sufficient non-human sequences to characterize oral microbial communities, including
detection of bacteria linked to oral disease (e.g. Prevotella melaninogenica). For comparison, two samples were
sequenced using standard full genome library preparation without exome capture and we found no systematic
bias of metagenomic information between exome-captured and non-captured data.
CONCLUSIONS: DNA from human saliva samples, collected and extracted using standard procedures, can be used to
successfully sequence high quality human exomes, and metagenomic data can be derived from non-human reads.
We find that individuals from the Kalahari carry a higher oral pathogenic microbial load than samples surveyed in
the Human Microbiome Project. Additionally, rare variants present in the exomes suggest strong population structure
across different KhoeSan populations.Keywords: KhoeSan, Metagenomics, Microbiome, Genetic diversity, Exome
Recommended from our members
SharptonThomasMicrobiologyExomeCaptureSaliva.pdf
BACKGROUND: Targeted capture of genomic regions reduces sequencing cost while generating higher coverage by
allowing biomedical researchers to focus on specific loci of interest, such as exons. Targeted capture also has the
potential to facilitate the generation of genomic data from DNA collected via saliva or buccal cells. DNA samples
derived from these cell types tend to have a lower human DNA yield, may be degraded from age and/or have
contamination from bacteria or other ambient oral microbiota. However, thousands of samples have been previously
collected from these cell types, and saliva collection has the advantage that it is a non-invasive and appropriate for a
wide variety of research.
RESULTS: We demonstrate successful enrichment and sequencing of 15 South African KhoeSan exomes and 2 full
genomes with samples initially derived from saliva. The expanded exome dataset enables us to characterize genetic
diversity free from ascertainment bias for multiple KhoeSan populations, including new exome data from six HGDP
Namibian San, revealing substantial population structure across the Kalahari Desert region. Additionally, we discover
and independently verify thirty-one previously unknown KIR alleles using methods we developed to accurately map
and call the highly polymorphic HLA and KIR loci from exome capture data. Finally, we show that exome capture of
saliva-derived DNA yields sufficient non-human sequences to characterize oral microbial communities, including
detection of bacteria linked to oral disease (e.g. Prevotella melaninogenica). For comparison, two samples were
sequenced using standard full genome library preparation without exome capture and we found no systematic
bias of metagenomic information between exome-captured and non-captured data.
CONCLUSIONS: DNA from human saliva samples, collected and extracted using standard procedures, can be used to
successfully sequence high quality human exomes, and metagenomic data can be derived from non-human reads.
We find that individuals from the Kalahari carry a higher oral pathogenic microbial load than samples surveyed in
the Human Microbiome Project. Additionally, rare variants present in the exomes suggest strong population structure
across different KhoeSan populations.Keywords: Exomes, Microbiome, Genetic diversity, KhoeSan, Metagenomic