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Articles by Katherine Nash in JoVE
JoVE General
Technieken voor Imaging Ca 2 + Signalering in Human Sperm
1School of Biosciences, University of Birmingham, 2School of Medicine, University of Birmingham, 3Centre for Human Reproductive Science, Birmingham Women’s Hospital
Stimulus-opgeroepen [Ca
Other articles by Katherine Nash on PubMed
Acute Injury Patterns of Intimate Partner Violence Victims
Although millions of women receive injuries from intimate partner violence (IPV) each year in the United States alone, there has been only limited research of acute injury patterns and the types, locations, and mechanisms of IPV injuries. The mechanism of being punched to the face with a fist resulting in blunt trauma-related injuries is most commonly reported. Strangulation, especially manual strangulation, is a frequently cited mechanism of injury; however, less is known about the types of injuries that result from strangulation. In general, clinicians should assess all patients who present for treatment of head, neck, and face injuries for IPV. There is little consistency between and much inaccuracy with medical terms used to describe types of injuries. To increase the accuracy and generalizability of findings from studies of acute IPV injuries, researchers need to use more standardized medical forensic terminology.
Mobilisation of Ca2+ Stores and Flagellar Regulation in Human Sperm by S-nitrosylation: a Role for NO Synthesised in the Female Reproductive Tract
Generation of NO by nitric oxide synthase (NOS) is implicated in gamete interaction and fertilisation. Exposure of human spermatozoa to NO donors caused mobilisation of stored Ca(2+) by a mechanism that did not require activation of guanylate cyclase but was mimicked by S-nitroso-glutathione (GSNO; an S-nitrosylating agent). Application of dithiothreitol, to reduce protein -SNO groups, rapidly reversed the actions of NO and GSNO on [Ca(2+)](i). The effects of NO, GSNO and dithiothreitol on sperm protein S-nitrosylation, assessed using the biotin switch method, closely paralleled their actions on [Ca(2+)](i). Immunofluorescent staining revealed constitutive and inducible NOS in human oviduct and cumulus (the cellular layer investing the oocyte). 4,5-diaminofluorescein (DAF) staining demonstrated production of NO by these tissues. Incubation of human sperm with oviduct explants induced sperm protein S-nitrosylation resembling that induced by NO donors and GSNO. Progesterone (a product of cumulus cells) also mobilises stored Ca(2+) in human sperm. Pre-treatment of sperm with NO greatly enhanced the effect of progesterone on [Ca(2+)](i), resulting in a prolonged increase in flagellar excursion. We conclude that NO regulates mobilisation of stored Ca(2+) in human sperm by protein S-nitrosylation, that this action is synergistic with that of progesterone and that this synergism is potentially highly significant in gamete interactions leading to fertilisation.
Can One Accurately Date a Bruise? State of the Science
Forensic nursing experts and other health professionals often testify regarding the injuries women and men receive from violence. Bruise discoloration can provide an opportunity for health professionals to grossly estimate the age of impact and determine if it is consistent with a given reported history. However, there is much confusion in the literature and clinical practice as to the accuracy of dating bruises. This article will demonstrate that using the color of the bruise as the primary criteria to determine its age is not the best practice. The limited available research and related literature on the topic are flawed and inconsistent. Finally, recommendations will be made for future research and clinical practice.
Ca2+-stores in Sperm: Their Identities and Functions
Intracellular Ca2+ stores play a central role in the regulation of cellular [Ca2+](i) and the generation of complex [Ca2+] signals such as oscillations and waves. Ca2+ signalling is of particular significance in sperm cells, where it is a central regulator in many key activities (including capacitation, hyperactivation, chemotaxis and acrosome reaction) yet mature sperm lack endoplasmic reticulum and several other organelles that serve as Ca2+ stores in somatic cells. Here, we review i) the evidence for the expression in sperm of the molecular components (pumps and channels) which are functionally significant in the activity of Ca2+ stores of somatic cells and ii) the evidence for the existence of functional Ca2+ stores in sperm. This evidence supports the existence of at least two storage organelles in mammalian sperm, one in the acrosomal region and another in the region of the sperm neck and midpiece. We then go on to discuss the probable identity of these organelles and their discrete functions: regulation by the acrosome of its own secretion and regulation by membranous organelles at the sperm neck (and possibly by the mitochondria) of flagellar activity and hyperactivation. Finally, we consider the ability of the sperm discretely to control mobilisation of these stores and the functional interaction of stored Ca2+ at the sperm neck/midpiece with CatSper channels in the principal piece in regulation of the activities of mammalian sperm.
Potential Economic Benefit of Cleft Lip and Palate Repair in Sub-Saharan Africa
Acceptance of basic surgical care as an essential element of any properly functioning health system is growing. To justify investment in surgical interventions, donors require estimates of the economic benefit of treating surgical disease. The present study aimed to establish a methodology for valuing the potential economic benefit of surgical intervention using cleft lip and palate (CLP) in sub-Saharan Africa (SSA) as a model.
