Mitochondria are maternally transmitted; hence, their genome can only make a direct and adaptive response to selection through females, whereas males represent an evolutionary dead end. In theory, this creates a sex-specific selective sieve, enabling deleterious mutations to accumulate in mitochondrial genomes if they exert male-specific effects. We tested this hypothesis, expressing five mitochondrial variants alongside a standard nuclear genome in Drosophila melanogaster, and found striking sexual asymmetry in patterns of nuclear gene expression.
View Article and Find Full Text PDFBackground: Bariatric surgery is an effective means of managing weight and reducing medical co-morbidities in the obese patient. However, psychological difficulties are common and adequate multidisciplinary support is vital for post-surgical success. Videoconferencing is potentially a vehicle for the delivery of support to patients residing in remote areas.
View Article and Find Full Text PDFHemiclones are naturally occurring or artificially produced individuals that share a single specific genetic haplotype. Natural hemiclones are produced via hybridization between two closely related species, whereas hemiclonal analysis in Drosophila is carried out in the laboratory via crosses with artificially created 'clone-generator' females with a specific genetic make-up. Hemiclonal analysis in Drosophila has been applied successfully to date to obtain measures of standing genetic variation for numerous traits.
View Article and Find Full Text PDFWe examine problems resulting from the narrow empirical focus associated with evidence-based nursing, including the deleterious influence of vested interests, disattention to patients' experiences, underestimation of the importance of social processes, lack of an individualized research perspective, marginalization of other forms of knowledge, and the undermining of patients' autonomy. Addressing each problem in turn, we argue that inclusion of patients at all stages of evidence-based practice can counter or ameliorate these problems. While we concede that patient involvement is not a complete solution to the problem of empiricism, it is the most effective means available to defend nursing values.
View Article and Find Full Text PDFBackground: The evolution of female choice mechanisms favouring males of their own kind is considered a crucial step during the early stages of speciation. However, although the genomics of mate choice may influence both the likelihood and speed of speciation, the identity and location of genes underlying assortative mating remain largely unknown.
Methods And Findings: We used mate choice experiments and gene expression analysis of female Drosophila melanogaster to examine three key components influencing speciation.
Aim And Objective: To explore why innovations in service and delivery are adopted and how they are then successfully implemented and eventually assimilated into routine nursing practice.
Background: The 'Productive Ward' is a national quality improvement programme that aims to engage nursing staff in the implementation of change at ward level.
Design: Mixed methods (analysis of routine data, online survey, interviews) to apply an evidence-based diffusion of innovations framework.
Minerva Chir
December 2010
Obesity is the leading public health concern in the industrialized world with the advent of the very obese or "super obese" increasing exponentially. Bariatric surgery remains the only effective and enduring treatment for morbid obesity and can be safely accomplished in experienced centers. Surgery in the very obese may be considered high-risk: however, this risk may be managed with an experienced bariatric surgery team, appropriate anesthetic consideration, preoperative risk assessment, employment of venothrombotic event prevention, preoperative weight loss, and understanding of particular anatomic considerations.
View Article and Find Full Text PDFBackground: Meticillin-resistant Staphylococcus aureus (MRSA) is endemic within the United Kingdom health care sector. Recent campaigns to reduce health care-associated infection have rested on increasing staff accountability and ownership of the problem and its solutions. However, the existence of reservoirs of colonization in the community now creates ambiguity about sources, which may undermine preventative strategies.
View Article and Find Full Text PDFJ Am Acad Child Adolesc Psychiatry
November 2010
Objective: To highlight recent discoveries in the area of genomic copy number variation in neuropsychiatric disorders including intellectual disability, autism, and schizophrenia. To emphasize new principles emerging from this area, involving the genetic architecture of disease, pathophysiology, and diagnosis.
Method: Review of studies published in PubMed including classic studies of genomic disorders and microarray and copy number studies in normal controls, intellectual disability, autism, and schizophrenia.
Am J Med Genet B Neuropsychiatr Genet
June 2010
Research has implicated mutations in the gene for neurexin-1 (NRXN1) in a variety of conditions including autism, schizophrenia, and nicotine dependence. To our knowledge, there have been no published reports describing the breadth of the phenotype associated with mutations in NRXN1. We present a medical record review of subjects with deletions involving exonic sequences of NRXN1.
View Article and Find Full Text PDFA growing body of experimental and field data shows that selective pressures often differ between males and females. Surprisingly,to date, little attempt has been made to formalize a metric expressing the relative behavior of directional selection in the two sexes. We propose an index that describes the extent to which concordant or antagonistic selection is operating between the sexes for a given trait.
View Article and Find Full Text PDFWhen selective pressures differ between males and females, the genes experiencing these conflicting evolutionary forces are said to be sexually antagonistic. Although the phenotypic effect of these genes has been documented in both wild and laboratory populations, their identity, number, and location remains unknown. Here, by combining data on sex-specific fitness and genome-wide transcript abundance in a quantitative genetic framework, we identified a group of candidate genes experiencing sexually antagonistic selection in the adult, which correspond to 8% of Drosophila melanogaster genes.
View Article and Find Full Text PDFThis paper describes the use of Group Schema Therapy for Eating Disorders (ST-E-g) in a case series of eight participants with chronic eating disorders and high levels of co-morbidity. Treatment was comprised of 20 sessions which included cognitive, experiential, and interpersonal strategies, with an emphasis on behavioral change. Specific schema-based strategies focused on bodily felt-sense and body-image, as well as emotional regulation skills.
View Article and Find Full Text PDFAbnormalities of the medial temporal lobe have been consistently demonstrated in schizophrenia. A common functional polymorphism, Val108/158Met, in the putative schizophrenia susceptibility gene, catechol-O-methyltransferase (COMT), has been shown to influence medial temporal lobe function. However, the effects of this polymorphism on volumes of medial temporal lobe structures, particularly in patients with schizophrenia, are less clear.
View Article and Find Full Text PDFThe purpose of this research was to develop a tissue-engineered intrasynovial flexor tendon construct with the use of an acellularized flexor tendon scaffold repopulated with intrasynovial tendon cells. New Zealand white rabbit intrasynovial flexor tendons were acellularized by the following methods: high concentration NaCl + SDS, Trypsin/EDTA, Trypsin/EDTA + Triton X-100, Triton X-100, Triton X-100 + SDS, and freezing at -70 degrees C followed by Trypsin/EDTA + Triton X-100. Epitenon and endotenon cells were also isolated from rabbit intrasynovial tendons and expanded in culture.
View Article and Find Full Text PDFSurg Clin North Am
October 2009
Much has been learned about the diagnosis and treatment of Zollinger-Ellison Syndrome (ZES), and certain questions require further investigation. Delay in diagnosis of ZES is still a significant problem, and clinical suspicion should be elevated. The single best imaging modality for localization and staging of ZES is somatostatin receptor scintigraphy.
View Article and Find Full Text PDFFly (Austin)
August 2009
One basic condition of postmating sexual selection is that females mate more than once before fertilizing their ova. Knowledge of the frequency and extent of multiple mating in a given population or species is therefore important in order to fully understand the potential for sexual selection, in the form of sperm competition, sexual conflict and cryptic female choice. Surprisingly, there are only a handful of studies that have attempted to estimate the frequency of multiple mating in insects (including Drosophila) and none have made direct observations over extended periods of time.
View Article and Find Full Text PDFIn Drosophila melanogaster, mating radically transforms female physiology and behaviour. Post-mating responses include an increase in the oviposition rate, a reduction in female receptivity and an activation of the immune system. The fitness consequences of mating are similarly dramatic--females must mate once in order to produce fertile eggs, but additional matings have a clear negative effect.
View Article and Find Full Text PDFGenetic studies are refining our understanding of neurodevelopmental mechanisms in autism. Some autism-related mutations appear to disrupt genes regulated by neuronal activity, which are especially important in development of the postnatal nervous system. Gene replacement studies in mice indicate that the developmental window to ameliorate symptoms may be wider than previously anticipated.
View Article and Find Full Text PDFThe P21-activated kinase PAK3 is critical for cognitive development and truncating mutations cause non-syndromic mental retardation (MR). Missense mutations are also associated with psychotic disorders, most commonly with schizophrenia involving premorbid MR, namely "pfropfschizophrenie". We set out to measure the frequency of sequence variants in PAK3 in schizophrenia without premorbid MR.
View Article and Find Full Text PDFSpermatozoa are the most diverse of all animal cells. Variation in size alone is enormous and yet there are still no clear evolutionary explanations that can account for such diversity. The basic genetics of sperm form is also poorly understood, although sperm size is known to have a strong genetic component.
View Article and Find Full Text PDFTo find inherited causes of autism-spectrum disorders, we studied families in which parents share ancestors, enhancing the role of inherited factors. We mapped several loci, some containing large, inherited, homozygous deletions that are likely mutations. The largest deletions implicated genes, including PCDH10 (protocadherin 10) and DIA1 (deleted in autism1, or c3orf58), whose level of expression changes in response to neuronal activity, a marker of genes involved in synaptic changes that underlie learning.
View Article and Find Full Text PDFIntralocus sexual conflict, which occurs when a trait is selected in opposite directions in the two sexes, is a taxonomically widespread phenomenon. The strongest genetic evidence for a gender load due to intralocus sexual conflict comes from the Drosophila melanogaster laboratory model system, in which a negative genetic correlation between male and female lifetime fitness has been observed. Here, using a D.
View Article and Find Full Text PDFBackground: Retinal bipolar cells comprise a diverse group of neurons. Cone bipolar cells and rod bipolar cells are so named for their connections with cone and rod photoreceptors, respectively. Morphological criteria have been established that distinguish nine types of cone bipolar cells and one type of rod bipolar cell in mouse and rat.
View Article and Find Full Text PDF