Before fertilization, spermatozoa must undergo calcium-regulated acrosome exocytosis in response to physiological stimuli such as progesterone and zona pellucida. Our laboratory has elucidated the signaling cascades accomplished by different sphingolipids during human sperm acrosomal exocytosis. Recently, we established that ceramide increases intracellular calcium by activating various channels and stimulating the acrosome reaction.
View Article and Find Full Text PDFBackground: Stress and elevated cortisol levels have negative effects on fertility, although there is controversy about the effect of cortisol on human sperm. One study reported that hydrocortisone (HC), the synthetic form of cortisol, does not activate CatSper channel but is able to inhibit its activation by progesterone (Pg). However, subsequent reports showed that HC has an agonist effect on CatSper, producing intracellular Ca ([Ca ] ) increases.
View Article and Find Full Text PDFIntroduction: Nerve conduction studies (NCS) have been considered as the gold standard in carpal tunnel syndrome (CTS) diagnosis, despite correlation between clinical symptomatology and NCS severity has shown to be poor. In fact, clinical symptoms precede NCS changes in months or years. Few papers have been published about the clinical response to treatment of clinically typical CTS, but with normal NCS (NNCS).
View Article and Find Full Text PDFChildren's performance in arithmetic word problems (AWPs) predicts their academic success and their future employment and earnings in adulthood. Understanding the nature and difficulties of interpreting and solving AWPs is important for theoretical, educational, and social reasons. We investigated the relation between primary school children's performance in different types of AWPs and their basic cognitive abilities (reading comprehension, fluid intelligence, inhibition, and updating processes).
View Article and Find Full Text PDFObjective: To assess the PTS method in neuromonitoring of thoracic pedicle screws in a young cohort of AIS patients. The accuracy of both PTS (Pulse-train stimulation) and SPS (Single-pulse stimulation) techniques in the detection of misplaced thoracic screws was compared with special reference to the screws placed at the concavity and the convexity of the curve.
Patients And Methods: A single-center prospective clinical cohort study.
Background: During embryogenesis lateral symmetry is broken, giving rise to Left/Right (L/R) breast tissues with distinct identity. L/R-sided breast tumors exhibit consistently-biased incidence, gene expression, and DNA methylation. We postulate that a differential L/R tumor-microenvironment crosstalk generates different tumorigenesis mechanisms.
View Article and Find Full Text PDFThe genus Copitarsia Hampson (Lepidoptera. Noctuidae) includes agricultural pests of at least 48 crop plants and they are distributed from Mexico to southern South America. In South America, from Venezuela to Chile and Argentina, Copitarsia incommoda (Walker) is one of the most economic important species of the genus.
View Article and Find Full Text PDFHuman voltage-gated proton channels (hHv1) extrude protons from cells to compensate for charge and osmotic imbalances due metabolism, normalizing intracellular pH and regulating protein function. Human albumin (Alb), present at various levels throughout the body, regulates oncotic pressure and transports ligands. Here, we report Alb is required to activate hHv1 in sperm and neutrophils.
View Article and Find Full Text PDFIntroduction: Nerve conduction studies (NCS) have been considered as the gold standard in carpal tunnel syndrome (CTS) diagnosis, despite correlation between clinical symptomatology and NCS severity has shown to be poor. In fact, clinical symptoms precede NCS changes in months or years. Few papers have been published about the clinical response to treatment of clinically typical CTS, but with normal NCS (NNCS).
View Article and Find Full Text PDFBackground: The signaling pathways of the intracellular second messengers cAMP and Ca play a crucial role in numerous physiological processes in human spermatozoa. One such process is the acrosome reaction (AR), which is necessary for spermatozoa to traverse the egg envelope and to expose a fusogenic membrane allowing the egg-sperm fusion. Progesterone and zona pellucida elicit an intracellular Ca increase that is needed for the AR in the mammalian spermatozoa.
View Article and Find Full Text PDFMammalian sperm acquire ability to fertilize through a process called capacitation, occurring after ejaculation and regulated by both female molecules and male decapacitation factors. Bicarbonate and calcium present in the female reproductive tract trigger capacitation in sperm, leading to acrosomal responsiveness and hyperactivated motility. Male decapacitating factors present in the semen avert premature capacitation, until detached from the sperm surface.
View Article and Find Full Text PDFThe taxonomy of five South American species of Dargida Walker currently allocated in Leucania Ochsenheimer (four species) and in Lasionycta Aurivillius (one species) is revised. Leucania roseilinea (Köhler, 1947), Leucania phaeoneura Hampson, 1913, Leucania mocoides Dognin, 1897, Leucania alboradiata (Hampson, 1905) and Lasionycta radiata (Köhler, 1966), are here combined with the genus Dargida Walker for the first time (comb. nov.
View Article and Find Full Text PDFIn a previous paper, we have demonstrated that: (1) local injection of corticosteroids for carpal tunnel syndrome (CTS) is as effective as decompressive surgery, at 1-year follow-up; and (2) surgery has an additional benefit in the 2-year follow-up. In this study, we assess the long-term outcomes of both therapies in an observational extension of the patients originally enrolled in our randomized clinical trial. Patients were included in an open, randomized clinical trial, comparing injections versus surgery in CTS.
View Article and Find Full Text PDFExocytosis of spermatozoon's secretory vesicle, named acrosome reaction (AR), is a regulated event that plays a central role in fertilization. It is coupled to a complex calcium signaling. Ceramide is a multitasking lipid involved in exocytosis.
View Article and Find Full Text PDFRev Soc Bras Med Trop
February 2020
Introduction: The genus Haemagogus Williston is restricted to Central America and North and middle of South America and it includes numerous species of yellow fever virus vectors.
Methods: Adult female and larvae mosquitoes were collected using hand aspirators and dipper and pipette, respectively.
Results: The first record of a species of Haemagogus and particularly of Haemagogus spegazzinii was from La Pampa, Argentina.
Using a de novo peptide inhibitor, Corza6 (C6), we demonstrate that the human voltage-gated proton channel (hHv1) is the main pathway for H efflux that allows capacitation in sperm and permits sustained reactive oxygen species (ROS) production in white blood cells (WBCs). C6 was identified by a phage-display strategy whereby ∼1 million novel peptides were fabricated on an inhibitor cysteine knot (ICK) scaffold and sorting on purified hHv1 protein. Two C6 peptides bind to each dimeric channel, one on the S3-S4 loop of each voltage sensor domain (VSD).
View Article and Find Full Text PDFOocyte maturation does not entirely support all the nuclear and cytoplasmic changes that occur physiologically, and it is poorly understood whether maturation affects the competence of cortical granules to secrete their content during cortical reaction. Here, we characterize cortical granule exocytosis (CGE) in live mouse oocytes activated by strontium chloride using the fluorescent lectin FITC-LCA. We compared the kinetic of CGE between ovulated ( matured, IVO) and matured (IVM) mouse oocytes.
View Article and Find Full Text PDFCardiopulmonary resuscitation requires the provider to adopt positions that could be dangerous for his or her spine, specifically affecting the muscles and ligaments in the lumbar zone and the scapular spinal muscles. Increased fatigue caused by muscular activity during the resuscitation could produce a loss of quality and efficacy, resulting in compromising resuscitation. The aim of this study was to evaluate the maximum time a rescuer can perform uninterrupted chest compressions correctly without muscle fatigue.
View Article and Find Full Text PDFThe taxonomy of the hitherto unplaced taxon Porosagrotis carolia Schaus, 1929 is evaluated and the name is taken out of taxonomic limbo and combined with Feltia Walker, 1856. Feltia carolia comb. nov.
View Article and Find Full Text PDFPurpose: To evaluate the degree of acute or progressive lateral compression needed to cause neurologic injury to the spinal cord assessed by electrophysiological monitoring.
Methods: In five domestic pigs, the spinal cord was exposed and compressed between T8-T9 roots using a precise compression device. Two sticks placed on both sides of the spinal cord were sequentially brought together (0.
Regulated secretion is a central issue for the specific function of many cells; for instance, mammalian sperm acrosomal exocytosis is essential for egg fertilization. ARF6 (ADP-ribosylation factor 6) is a small GTPase implicated in exocytosis, but its downstream effectors remain elusive in this process. We combined biochemical, functional, and microscopy-based methods to show that ARF6 is present in human sperm, localizes to the acrosomal region, and is required for calcium and diacylglycerol-induced exocytosis.
View Article and Find Full Text PDFThe acrosome reaction is a unique event in the lifespan of sperm characterized by the exocytosis of the acrosomal content and the release of hybrid vesicles formed by patches of the outer acrosomal membrane and the plasma membrane. This unique regulated exocytosis is mediated by essentially the same membrane fusion machinery present in neuroendocrine cells. However, whereas secretion in neuroendocrine cells occurs in less than a second, the acrosome reaction is normally assessed after several minutes of incubation with inducers.
View Article and Find Full Text PDFStudy Design: Experimental study, OBJECTIVES: To document and analyze the neurophysiological changes during spinal cord monitoring when thoracic pedicle screws are intentionally placed within the spinal canal.
Summary Of Background Data: Although the rate of misplaced screws is relatively high, few patients have neurological impairment. This suggests that a significant degree of medullary displacement and/or compression is necessary to produce neurophysiological changes.
Background Context: The correction of severe spinal deformities by an isolated posterior approach often involves cord manipulation together with hypotensive anesthesia. To date, the efficiency of methods to increase the tolerance of the cord to displacement and the influence of hypotension on this tolerance is yet to be assessed.
Purpose: The objective of this study was to determine the limits of cord displacement before the disappearance of neurophysiologic signals.