RESUMO
After ejaculation, mammalian sperm undergo a series of molecular events conducive to the acquisition of fertilizing competence. These events are collectively known as capacitation and involve acrosomal responsiveness and a vigorous sperm motility called hyperactivation. When mimicked in the laboratory, capacitating bovine sperm medium contains bicarbonate, calcium, albumin and heparin, among other components. In this study, we aimed at establishing a new capacitation protocol for bovine sperm, using calcium ionophore. Similar to our findings using mouse sperm, bovine sperm treated with Ca2+ ionophore A23187 were quickly immobilized. However, these sperm initiated capacitation after ionophore removal in fresh medium without heparin, and independent of the Protein Kinase A. When A23187-treated sperm were used on in vitro fertilization (IVF) procedures without heparin, eggs showed cleavage rates similar to standardized IVF protocols using heparin containg synthetic oviduct fluid (IVF-SOF). However, when A23187 pre-treated sperm were further used for inseminating eggs in complete IVF-SOF-heparin, a significantly higher percentage of embryo development was observed, suggesting a synergism between two different signaling pathways during bovine sperm capacitation. These results have the potential to improve current protocols for bovine IVF that could also be applied in other species of commercial interest.
Assuntos
Calcimicina , Ionóforos de Cálcio , Criopreservação , Fertilização in vitro , Preservação do Sêmen , Capacitação Espermática , Espermatozoides , Animais , Bovinos , Masculino , Ionóforos de Cálcio/farmacologia , Criopreservação/veterinária , Criopreservação/métodos , Fertilização in vitro/veterinária , Fertilização in vitro/métodos , Calcimicina/farmacologia , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Capacitação Espermática/efeitos dos fármacos , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Feminino , Técnicas de Cultura Embrionária/veterinária , Desenvolvimento Embrionário/efeitos dos fármacosRESUMO
BACKGROUND: Exposure of humans and animals to heavy metals is increasing day-by-day; thus, lead even today remains of significant public health concern. According to CDC, blood lead reference value (BLRV) ranges from 3.5 µg/dl to 5 µg/dl in adults. Recently, almost 2.6% decline in male fertility per year has been reported but the cause is not well established. Lead (Pb2+) affects the size of testis, semen quality, and secretory functions of prostate. But the molecular mechanism(s) of lead toxicity in sperm cells is not clear. Thus, present study was undertaken to evaluate the adverse effects of lead acetate at environmentally relevant exposure levels (0.5, 5, 10 and 20 ppm) on functional and molecular dynamics of spermatozoa of bucks following in vitro exposure for 15 min and 3 h. RESULTS: Lead significantly decreased motility, viable count, and motion kinematic patterns of spermatozoa like curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency and maximum amplitude of head lateral displacement even at 5 ppm concentration. Pb2+ modulated intracellular cAMP and Ca2+ levels in sperm cells through L-type calcium channels and induced spontaneous or premature acrosome reaction (AR) by increasing tyrosine phosphorylation of sperm proteins and downregulated mitochondrial transmembrane potential. Lead significantly increased DNA damage and apoptosis as well. Electron microscopy studies revealed Pb2+ -induced deleterious effects on plasma membrane of head and acrosome including collapsed cristae in mitochondria. CONCLUSIONS: Pb2+ not only mimics Ca2+ but also affects cellular targets involved in generation of cAMP, mitochondrial transmembrane potential, and ionic exchange. Lead seems to interact with Ca2+ channels because of charge similarity and probably enters the sperm cell through these channels and results in hyperpolarization. Our findings also indicate lead-induced TP and intracellular Ca2+ release in spermatozoa which in turn may be responsible for premature acrosome exocytosis which is essential feature of capacitation for fertilization. Thus, lead seems to reduce the fertilizing capacity of spermatozoa even at 0.5 ppm concentrations.
Assuntos
Reação Acrossômica , Acrossomo , Cálcio , Chumbo , Motilidade dos Espermatozoides , Espermatozoides , Masculino , Espermatozoides/efeitos dos fármacos , Cálcio/metabolismo , Motilidade dos Espermatozoides/efeitos dos fármacos , Animais , Acrossomo/efeitos dos fármacos , Chumbo/toxicidade , Reação Acrossômica/efeitos dos fármacos , AMP Cíclico/metabolismo , Bovinos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Análise do Sêmen , Dano ao DNA/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Compostos Organometálicos/farmacologiaRESUMO
Although under appropriate laboratory conditions, sperm from different mammalian species can be capacitated in vitro, the optimal conditions for sperm capacitation in the stallion have been elusive. This study evaluated the effect of different capacitating inducers in Whitten and Tyrode media and assessed their impact on capacitation-related factors. Stallion sperm were incubated with different combinations of capacitating inducers at 38.5 °C in an air atmosphere. Sperm quality variables such as motility, mitochondrial membrane potential, and lipid peroxidation were assessed. Membrane fluidity and intracellular calcium levels were evaluated as early markers of capacitation, while tyrosine phosphorylation events and the sperm's ability to perform acrosomal exocytosis were used as late capacitation markers. Finally, these sperm were evaluated using a heterologous zona pellucida binding assay. The findings confirm that capacitating conditions evaluated increase intracellular calcium levels and membrane fluidity in both media. Similarly, including 2 or 3 inducers in both media increased tyrosine phosphorylation levels and acrosomal exocytosis after exposure to progesterone, confirming that stallion sperm incubated in these conditions shows cellular and molecular changes consistent with sperm capacitation. Furthermore, the zona pellucida binding assay confirmed the binding capacity of sperm incubated in capacitation conditions, a key step for stallion in vitro fertilization success. Further studies are needed to evaluate the effect of these conditions on in vitro fertilization in the horse.
Assuntos
Capacitação Espermática , Espermatozoides , Animais , Capacitação Espermática/efeitos dos fármacos , Masculino , Cavalos/fisiologia , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Cálcio/metabolismo , Zona Pelúcida/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , FosforilaçãoRESUMO
To acquire the ability to fertilize the egg, mammalian spermatozoa must undergo a series of changes occurring within the highly synchronized and specialized environment of the female reproductive tract, collectively known as capacitation. In an attempt to replicate this process in vitro, various culture media for mouse sperm were formulated over the past decades, sharing a similar overall composition but differing mainly in ion concentrations and metabolic substrates. The widespread use of the different media to study the mechanisms of capacitation might hinder a comprehensive understanding of this process, as the medium could become a confounding variable in the analysis. In this context, the present side-by-side study compares the influence of four commonly used culture media (FD, HTF and two TYH versions) on mouse sperm capacitation. We evaluated the induction of protein kinase A phosphorylation pathway, motility, hyperactivation and acrosome reaction. Additionally, in vitro fertilization and embryo development were also assessed. By analyzing these outcomes in two mouse colonies with different reproductive performance, our study provides critical insights to improve the global understanding of sperm function. The results obtained highlight the importance of considering variations in medium composition, and their potential implications for the future interpretation of results.
Assuntos
Reação Acrossômica , Meios de Cultura , Fertilização in vitro , Capacitação Espermática , Espermatozoides , Animais , Capacitação Espermática/efeitos dos fármacos , Masculino , Camundongos , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Espermatozoides/metabolismo , Fertilização in vitro/métodos , Feminino , Reação Acrossômica/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Fosforilação , Fertilização , Desenvolvimento Embrionário/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismoRESUMO
Sperm capacitation involves biochemical and physiological changes that enable sperm to fertilize the oocyte. It can be induced in vitro under controlled conditions that simulate the environment of the oviduct. While extensively studied in mammals, its approach in lizards remains absent. Understanding the mechanisms that ensure reproduction is essential for advancing the implementation of assisted reproductive technologies in this group. We aimed to perform a sperm analysis to determine if capacitation-related changes were induced after incubation with capacitating media. Fifteen males of Sceloporus torquatus were collected during the early stage of the reproductive season. The sperm were isolated from the seminal plasma and then diluted up to a volume of 150 µL using BWW medium to incubate with 5% CO2 at 30 °C for a maximum duration of 3 h. A fraction was retrieved hourly for ongoing sperm assessment. The sperm analysis included assessments of its motility, viability, the capacitation status using the chlortetracycline (CTC) assay, and the acrosome integrity with the lectin binding assay to detect changes during incubation. We found that total motility was maintained up to 2 h post incubation, after which it decreased. However, sperm viability remained constant. From that moment on, we observed a transition to a deeper and less symmetrical flagellar bending in many spermatozoa. The CTC assay indicated a reduction in the percentage of sperm showing the full (F) pattern and an increase in those exhibiting the capacitated (B) and reactive (RA) patterns, accompanied by an elevation in the percentage of damaged acrosomes as revealed by the lectin binding assay. In mammals, these changes are often associated with sperm capacitation. Our observations support the notion that this process may also occur in saurian. While sperm analysis is a valuable method for assessing certain functional changes, additional approaches are required to validate this process.
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BACKGROUND: Factors contributing to the limited success of in vitro fertilization in horses remain to be studied. In this work, we elucidated the effect of different essential capacitation media components, bicarbonate, and bovine serum albumin or polyvinyl-alcohol, and the incubation microenvironment on sperm parameters associated with capacitation, acrosome reaction, and their ability to activate oocytes via heterologous intracytoplasmic spermatozoa injection in equine cryopreserved spermatozoa. METHODS: Frozen-thawed spermatozoa underwent incubation at different time intervals in either Tyrode's albumin lactate pyruvate medium (non-capacitating; NC) or Tyrode's albumin lactate pyruvate supplemented with bicarbonate, bicarbonate and polyvinyl-alcohol, bicarbonate and bovine serum albumin, polyvinyl-alcohol and bovine serum albumin alone. Protein kinase A-phosphorylated substrates and tyrosine phosphorylation levels, sperm motility, and acrosome reaction percentages were evaluated. After determining the best condition media (capacitating; CAP), heterologous intracytoplasmic spermatozoa injection on pig oocytes was performed and the phospholipase C zeta sperm localization pattern was evaluated. RESULTS: Incubation of frozen-thawed equine spermatozoa with bicarbonate and polyvinyl-alcohol in atmospheric air for 45 min induced an increase in protein kinase A-phosphorylated substrates and tyrosine phosphorylation levels compared to NC condition. Sperm incubation in bicarbonate and polyvinyl-alcohol medium showed an increase in total motility and progressive motility with respect to NC (p ≤ 0.05). Interestingly, three parameters associated with sperm hyperactivation were modulated under bicarbonate and polyvinyl-alcohol conditions. The kinematic parameters curvilinear velocity and amplitude of lateral head displacement significantly increased, while straightness significantly diminished (curvilinear velocity: bicarbonate and polyvinyl-alcohol = 120.9 ± 2.9 vs. NC = 76.91 ± 6.9 µm/s) (amplitude of lateral head displacement: bicarbonate and polyvinyl-alcohol = 1.15 ± 0.02 vs. NC = 0.77 ± 0.03 µm) (straightness: bicarbonate and polyvinyl-alcohol = 0.76 ± 0.01 vs. NC = 0.87 ± 0.02) (p ≤ 0.05). Moreover, the spontaneous acrosome reaction significantly increased in spermatozoa incubated in this condition. Finally, bicarbonate and polyvinyl-alcohol medium was established as CAP medium. Although no differences were found in phospholipase C zeta localization pattern in spermatozoa incubated under CAP, equine spermatozoa pre-incubated in CAP condition for 45 min showed higher fertilization rates when injected into matured pig oocytes (NC: 47.6% vs. CAP 76.5%; p ≤ 0.05). CONCLUSION: These findings underscore the importance of bicarbonate and polyvinyl-alcohol in supporting critical events associated with in vitro sperm capacitation in the horse, resulting in higher oocyte activation percentages following heterologous intracytoplasmic spermatozoa injection. This protocol could have an impact on reproductive efficiency in the equine breeding industry.
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Hyperpolarization of the membrane potential (Em), a phenomenon regulated by SLO3 channels, stands as a central feature in sperm capacitation-a crucial process conferring upon sperm the ability to fertilize the oocyte. In vitro studies demonstrated that Em hyperpolarization plays a pivotal role in facilitating the mechanisms necessary for the development of hyperactivated motility (HA) and acrosomal exocytosis (AE) occurrence. Nevertheless, the physiological significance of sperm Em within the female reproductive tract remains unexplored. As an approach to this question, we studied sperm migration and AE incidence within the oviduct in the absence of Em hyperpolarization using a novel mouse model established by crossbreeding of SLO3 knock-out (KO) mice with EGFP/DsRed2 mice. Sperm from this model displays impaired HA and AE in vitro. Interestingly, examination of the female reproductive tract shows that SLO3 KO sperm can reach the ampulla, mirroring the quantity of sperm observed in wild-type (WT) counterparts, supporting that the HA needed to reach the fertilization site is not affected. However, a noteworthy distinction emerges-unlike WT sperm, the majority of SLO3 KO sperm arrive at the ampulla with their acrosomes still intact. Of the few SLO3 KO sperm that do manage to reach the oocytes within this location, fertilization does not occur, as indicated by the absence of sperm pronuclei in the MII-oocytes recovered post-mating. In vitro, SLO3 KO sperm fail to penetrate the ZP and fuse with the oocytes. Collectively, these results underscore the vital role of Em hyperpolarization in AE and fertilization within their physiological context, while also revealing that Em is not a prerequisite for the development of the HA motility, essential for sperm migration through the female tract to the ampulla.
RESUMO
As in most cells, intracellular pH regulation is fundamental for sperm physiology. Key sperm functions like swimming, maturation, and a unique exocytotic process, the acrosome reaction, necessary for gamete fusion, are deeply influenced by pH. Sperm pH regulation, both intracellularly and within organelles such as the acrosome, requires a coordinated interplay of various transporters and channels, ensuring that this cell is primed for fertilization. Consistent with the pivotal importance of pH regulation in mammalian sperm physiology, several of its unique transporters are dependent on cytosolic pH. Examples include the Ca2+ channel CatSper and the K+ channel Slo3. The absence of these channels leads to male infertility. This review outlines the main transport elements involved in pH regulation, including cytosolic and acrosomal pH, that participate in these complex functions. We present a glimpse of how these transporters are regulated and how distinct sets of them are orchestrated to allow sperm to fertilize the egg. Much research is needed to begin to envision the complete set of players and the choreography of how cytosolic and organellar pH are regulated in each sperm function.
Assuntos
Acrossomo , Citosol , Espermatozoides , Masculino , Concentração de Íons de Hidrogênio , Animais , Citosol/metabolismo , Humanos , Acrossomo/metabolismo , Espermatozoides/metabolismo , Mamíferos/metabolismo , Reação AcrossômicaRESUMO
Community health promotion offers a potential solution to persistent healthcare challenges, with community health workers playing a pivotal role. The Community Training Institute for Health Disparities (CTIHD) implemented a problem-solving curriculum in Community Health Promotion, integrating a competency-based learning model through two courses: Introduction to Community Health Promotion and Design of an Action Plan for the Promotion of Community Health. Each course comprised ten three-hour sessions, featuring pre/post-tests, evaluations, and a cognitive debriefing. Knowledge change was assessed using pre/post-test scores among 27 community leaders from southern Puerto Rico. Cohort 1 and Cohort 2 demonstrated an overall retention rate of 62.6% and 96.7%, respectively. Although differences in knowledge gained between cohorts and courses weren't statistically significant, a trend toward increased knowledge was noted. Cohort 1 experienced a 22% knowledge increase in Course 1 and a 24% increase in Course 2. Cohort 2 demonstrated a 41% knowledge increase in Course 1 and a 25% increase in Course 2. The CTIHD's Community Health Promotion Program has made significant strides in elevating awareness and knowledge, marking a positive step toward reducing health disparities and fostering healthier, empowered communities in southern Puerto Rico.
Assuntos
Agentes Comunitários de Saúde , Promoção da Saúde , Humanos , Porto Rico , Promoção da Saúde/métodos , Promoção da Saúde/organização & administração , Agentes Comunitários de Saúde/educação , Agentes Comunitários de Saúde/organização & administração , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Área Carente de Assistência Médica , Currículo , EmpoderamentoRESUMO
The cAMP-dependent protein kinase (PKA) is one of the most extensively distributed kinases among intracellular signal cascades, with a pivotal role in the regulation of various processes, including the capacitation of sperm cells. Traditional assessments of PKA activity relies on the utilization of [γ-32P] ATP and the Kemptide substrate. This methodology presents several major drawbacks, including high-costs and health risks derived from the manipulation of radioactive isotopes. In this work we introduce an enhanced non-radioactive assay for quantifying PKA activity, termed KiMSA which relies on the use of a fluorescent-labeled Kemptide (Kemptide-FITC). Once the kinase reaction is terminated, the products can be easily resolved through electrophoresis on an agarose gel and quantified by fluorescence densitometry. We show that the KiMSA assay is suitable for purified PKA, and also to address both basal and capacitation induced PKA activity in mouse sperm cells. Furthermore, the assay enables monitoring the inhibition of PKA with inhibitors such as sPKI and H-89 in live cells. Therefore, the experimental and optimal assay conditions are set so that the KiMSA assay can be used to either assess in vitro as well as in vivo PKA activity in sperm cells. Finally, this method allows for measurement of cAMP concentrations, rendering a versatile technique for the study of cAMP/PKA pathways.
RESUMO
Sperm capacitation is a critical process for male fertility. It involves a series of biochemical and physiological changes that occur in the female reproductive tract, rendering the sperm competent for successful fertilization. The precise mechanisms and, specifically, the role of mitochondria, in sperm capacitation remain incompletely understood. Previously, we revealed that in mouse sperm mitochondrial activity (e.g., oxygen consumption, membrane potential, ATP/ADP exchange, and mitochondrial Ca2+ ) increases during capacitation. Herein, we studied mitochondrial function by high-resolution respirometry (HRR) and reactive oxygen species production in capacitated (CAP) and non-capacitated (NC) human spermatozoa. We found that in capacitated sperm from normozoospermic donors, the respiratory control ratio increased by 36%, accompanied by a double oxygen consumption rate (OCR) in the presence of antimycin A. Extracellular hydrogen peroxide (H2 O2 ) detection was three times higher in CAP than in NC sperm cells. To confirm that H2 O2 production depends on mitochondrial superoxide ( O 2 · - $$ {\mathrm{O}}_2^{\cdotp -} $$ ) formation, we evaluated mitochondrial aconitase (ACO2) amount, activity, and role in the metabolic flux from the sperm tricarboxylic acid cycle. We estimated that CAP cells produce, on average by individual, (59 ± 22)% more O 2 · - $$ {\mathrm{O}}_2^{\cdotp -} $$ in the steady-state compared to NC cells. Finally, we analyzed two targets of oxidative stress: lipid peroxidation by western blot against 4-hydroxynonenal and succinate dehydrogenase (SDH) activity by HRR. We did not observe modifications in lipoperoxidation nor the activity of SDH, suggesting that during capacitation, the increase in mitochondrial H2 O2 production does not damage sperm and it is necessary for the normal CAP process.
Assuntos
Mitocôndrias , Sêmen , Humanos , Masculino , Feminino , Animais , Camundongos , Espécies Reativas de Oxigênio , Espermatozoides , SuperóxidosRESUMO
RESEARCH QUESTION: Can the addition of progesterone and neurotensin, molecular agents found in the female reproductive tract, after sperm washing increase the fertilization potential of human spermatozoa? DESIGN: (i) Cohort study of 24 men. Spermatozoa selected by swim-up were incubated in either progesterone or neurotensin (0.1-100 µM) for 1-4 h, and hyperactive motility and binding to hyaluronan (0.1-100 µM) were assessed. The effect of progesterone 10 µM on sperm function was assessed in a blinded manner, including: hyperactive motility, binding to hyaluronan, tyrosine phosphorylation, acrosome reaction and oxidative DNA damage. (i) Embryo safety testing [one-cell mouse embryo assay (MEA), endotoxin and sterility counts (nâ¯=â¯3)] in preclinical embryo models of IVF (murine and porcine, nâ¯=â¯7 each model) and a small preliminary human study (nâ¯=â¯4) of couples undergoing standard IVF with oocytes inseminated with spermatozoa ± 10 µM progesterone. RESULTS: Progesterone 10 µM increased sperm binding to hyaluronan, hyperactive motility and tyrosine phosphorylation (all P < 0.05). Neurotensin had no effect (P > 0.05). Progesterone 10 µM in human embryo culture media passed embryo safety testing (MEA, endotoxin concentration and sterility plate count). In preclinical models of IVF, the exposure of spermatozoa to progesterone 10 µM and oocytes to progesterone 1 µM was not detrimental, and increased the fertilization rate in mice and the blastocyst cell number in mice and pigs (all P ≤ 0.03). In humans, every transferred blastocyst that had been produced from spermatozoa exposed to progesterone resulted in a live birth. CONCLUSION: The addition of progesterone to sperm preparation media shows promise as an adjunct to current methods for increasing fertilization potential. Randomized controlled trials are required to determine the clinical utility of progesterone for improving IVF outcomes.
Assuntos
Infertilidade , Progesterona , Humanos , Masculino , Feminino , Animais , Camundongos , Suínos , Progesterona/farmacologia , Progesterona/metabolismo , Fertilização in vitro/métodos , Neurotensina/metabolismo , Neurotensina/farmacologia , Ácido Hialurônico/farmacologia , Estudos de Coortes , Sêmen , Espermatozoides/metabolismo , Infertilidade/metabolismo , Tirosina/metabolismo , Endotoxinas/metabolismo , Endotoxinas/farmacologiaRESUMO
Polyamines are polycationic molecules which contains two or more amino groups (-NH3+) highly charged at physiological pH, and among them we found spermine, spermidine, putrescine, and cadaverine. They interact with proteins, nucleic acids, modulate Ca2+, K+, and Na+ channels, and protect sperm from oxidative stress. In this work, we evaluate the effect of spermine, spermidine, and putrescine on the total, progressive and kinematic parameters of motility, capacitation, acrosome reaction, also in presence and absence of the dbcAMP, an analogue of the cAMP, and the IBMX, a phosphodiesterase inhibitor. In addition, we evaluated the intracellular concentrations of cAMP [cAMP]i, and performed an in silico analysis between polyamines and the sAC from mouse to predict the possible interaction among them. Our results showed that all polyamines decrease drastically the total, progressive and the kinetic parameters of sperm motility, decrease the capacitation, and only spermidine and putrescine impeded the acquisition of acrosome reaction. Moreover, the effect of polyamines was attenuated but not countered by the addition of db-cAMP and IBMX, suggesting a possible inhibition of the sAC. Also, the presence of polyamines induced a decrease of the [cAMP]i, and the in silico analysis predicted a strong interaction among polyamines and the sAC. Overall, the evidence suggests that probably the polyamines interact and inhibit the activity of the sAC.
Assuntos
Poliaminas , Putrescina , Masculino , Animais , Camundongos , Putrescina/farmacologia , Espermidina/farmacologia , Espermina , 1-Metil-3-Isobutilxantina , Motilidade dos Espermatozoides , SêmenRESUMO
OBJECTIVE: To study the relationship between the seminal sample quality of men with varicocele and sperm capacitation. DESIGN: Cross-sectional observational study. SETTING: Academic hospital. PATIENT(S): Seventy-six men (19 control and 57 with varicocele) were analyzed. INTERVENTION(S): Semen samples were submitted to a discontinuous density gradient for sperm selection. Sperm capacitation was induced using a human tubal fluid medium supplemented with bovine serum albumin. MAIN OUTCOME MEASURE(S): After capacitation induction, the sperm were assessed by capacitation state, computer-assisted sperm motility, mitochondrial activity, membrane integrity, acrosome reaction, and intracellular oxidative stress. RESULT(S): The capacitation period increased sperm motility, showing an increase in the average path velocity and a decrease in the straightness compared with sperm before capacitation (paired analysis). After capacitation, the rate of capacitated sperm, motility, and mitochondrial activity showed differences between groups (control and varicocele). The varicocele group showed lower mitochondrial activity and capacitation than the control group. On the other hand, no significant differences were observed in the other variables evaluated. CONCLUSION(S): Varicocele men showed less viable sperm and mitochondrial activity than control men after capacitation sperm. The induction of capacitation altered motility by increasing path velocity and decreasing straightness in all of the studied groups, evidencing the occurrence of hyperactivation.
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Sêmen , Varicocele , Humanos , Masculino , Capacitação Espermática/fisiologia , Motilidade dos Espermatozoides/fisiologia , Estudos TransversaisRESUMO
Capacitation is a series of physiological, biochemical, and metabolic changes experienced by mammalian spermatozoa. These changes enable them to fertilize eggs. The capacitation prepares the spermatozoa to undergo the acrosomal reaction and hyperactivated motility. Several mechanisms that regulate capacitation are known, although they have not been fully disclosed; among them, reactive oxygen species (ROS) play an essential role in the normal development of capacitation. NADPH oxidases (NOXs) are a family of enzymes responsible for ROS production. Although their presence in mammalian sperm is known, little is known about their participation in sperm physiology. This work aimed to identify the NOXs related to the production of ROS in guinea pig and mouse spermatozoa and define their participation in capacitation, acrosomal reaction, and motility. Additionally, a mechanism for NOXs' activation during capacitation was established. The results show that guinea pig and mouse spermatozoa express NOX2 and NOX4, which initiate ROS production during capacitation. NOXs inhibition by VAS2870 led to an early increase in the capacitation and intracellular concentration of Ca2+ in such a way that the spermatozoa also presented an early acrosome reaction. In addition, the inhibition of NOX2 and NOX4 reduced progressive motility and hyperactive motility. NOX2 and NOX4 were found to interact with each other prior to capacitation. This interaction was interrupted during capacitation and correlated with the increase in ROS. Interestingly, the association between NOX2-NOX4 and their activation depends on calpain activation, since the inhibition of this Ca2+-dependent protease prevents NOX2-NOX4 from dissociating and ROS production. The results indicate that NOX2 and NOX4 could be the most important ROS producers during guinea pig and mouse sperm capacitation and that their activation depends on calpain.
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Calpaína , Espécies Reativas de Oxigênio , Sêmen , Capacitação Espermática , Animais , Cobaias , Masculino , Camundongos , Calpaína/metabolismo , NADPH Oxidase 4/metabolismo , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sêmen/metabolismo , Espermatozoides/metabolismoRESUMO
Mammalian sperm capacitation involves biochemical and physiological changes, such as an increase in intracellular calcium ion concentration ([Ca2+]i), hyperpolarization of the plasma membrane potential and sperm hyperactivation, among others. These changes provide sperm with the ability to fertilize. In the bat Corynorhinus mexicanus, there is an asynchrony between spermatogenesis and sperm storage in the male with the receptivity of the female. For instance, in C. mexicanus, spermatogenesis occurs before the reproductive season. During the reproductive period, sperm are stored in the epididymis for a few months and the testis undergoes a regression, indicating low or almost null sperm production. Therefore, it is unclear whether the elements necessary for sperm fertilization success undergo maturation or preparation during epididymis storage. Here, we characterized pH-sensitive motility hyperactivation and Ca2+ influx in sperm, regulated by alkalinization and progesterone. In addition, by electrophysiological recordings, we registered currents that were stimulated by alkalinization and inhibited by RU1968 (a CatSper-specific inhibitor), strongly suggesting that these currents were evoked via CatSper, a sperm Ca2+-specific channel indispensable for mammalian fertilization. We also found hyperpolarization of the membrane potential, such as in other mammalian species, which increased according to the month of capture, reaching the biggest hyperpolarization during the mating season. In conclusion, our results suggest that C. mexicanus sperm have functional CatSper and undergo a capacitation-like process such as in other mammals, particularly Ca2+ influx and membrane potential hyperpolarization.
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Cálcio , Quirópteros , Animais , Masculino , Feminino , Cálcio/metabolismo , Quirópteros/metabolismo , Potenciais da Membrana/fisiologia , Sêmen , Espermatozoides/fisiologia , Motilidade dos EspermatozoidesRESUMO
Fundamento: el análisis del impacto de la gestión docente es un requerimiento de la responsabilidad social universitaria. Objetivo: analizar el impacto del curso electivo Ritmo Circadiano y Salud, a través de la apreciación de los estudiantes, en la Facultad de Ciencias Médicas "Salvador Allende", durante el curso 2022-2023. Métodos: se desarrolló una investigación descriptiva, no experimental, con enfoque cualitativo, aplicando la metodología del estudio de caso. Se utilizaron métodos teóricos: análisis-síntesis e inducción-deducción, y empíricos: revisión documental y entrevista grupal a estudiantes. Resultados: de manera unánime se manifestó por los estudiantes la adquisición de conocimientos nuevos, de importancia para la práctica profesional, mediante el asesoramiento en el procesamiento de información, para la participación en una actividad virtual no conocida, así como la posibilidad de vivenciar en su entorno una problemática de salud asociada al tema del curso. Conclusiones: la apreciación por los estudiantes participantes del curso electivo Ritmo Circadiano y Salud, indicó un impacto positivo desde los puntos de vista cognitivo, educativo y social.
Background: the analysis of the impact of teaching management is a requirement of university social responsibility. Objective: to analyze the impact of the elective course Circadian Rhythm and Health, through the appreciation of the students, in the "Salvador Allende" Faculty of Medical Sciences, during the 2022-2023 academic year. Method: a descriptive, non-experimental investigation was developed, with a qualitative approach, applying the case study methodology. Theoretical methods were used: analysis-synthesis and induction-deduction, and empirical ones: documentary review and group interview with students. Results: the students unanimously expressed the acquisition of new important knowledge for professional practice, through advice on information processing, for participation in an unknown virtual activity, as well as the possibility of experiencing in their environment a health problem associated with the topic of the course. Conclusions: the appreciation by the participating students of the elective course Circadian Rhythm and Health, indicated a positive impact from the cognitive, educational and social points of view.
Assuntos
Ritmo Circadiano , Educação Profissionalizante , Tutoria , Educação Médica , AprendizagemRESUMO
Fundamento: el acto de cuidar está implícito en el proceso de trabajo de los profesionales de la enfermería y sustentado en el uso de teorías y modelos que desarrollan aspectos filosóficos y humanísticos sobre el cuidado. Objetivo: diagnosticar el nivel de preparación de los profesionales de enfermería sobre los modelos enfermeros en los servicios de Neonatología. Métodos: se realizó un estudio descriptivo de corte transversal en el Hospital Ginecobstétrico "Ana Betancourt de Mora" de la Universidad de Ciencias Médicas de Camagüey durante 2022. Se aplicaron métodos teóricos: inductivo-deductivo, analítico-sintético e histórico-lógico; y empíricos: cuestionario para la caracterización de los profesionales y el diagnóstico del nivel de preparación en cuanto a teorías y modelos enfermeros. Resultados: el diagnóstico realizado permitió conocer las carencias de los enfermeros quienes reconocieron no haber recibido talleres, cursos y/o entrenamiento afines con su competencia y desempeño, su nivel de preparación estuvo entre adecuado y medianamente adecuado, a pesar de que la mayoría tenía más de cinco años de experiencia laboral. Conclusiones: los resultados evidenciaron la insuficiente preparación de los profesionales sobre las teorías y modelos enfermeros que constituyen base teórica y científica para las intervenciones con los pacientes recién nacidos ubicados en la sala de Neonatología.
Background: the act of caring is implicit in the work process of nursing professionals and is supported by the use of theories and models that develop philosophical and humanistic aspects of care. Objective: to diagnose the level of preparation of nursing professionals on nursing models in Neonatology services. Methods: a descriptive cross-sectional study was carried out at "Ana Betancourt de Mora" Gynecological and Obstetric Hospital belonged to the University of Medical Sciences in Camagüey during 2022. Inductive-deductive, analytical-synthetic and historical-logical approaches were applied as theoretical methods; a questionnaire for the characterization of the professionals and the diagnosis of the level of preparation in terms of nursing theories and models were used as empirical ones. Results: the diagnosis made allowed us to know the deficiencies of the nurses who recognized that they had not received workshops, courses and/or training related to their competence and performance, their level of preparation was between adequate and moderately adequate, despite the fact that the majority had more than five years of work experience. Conclusions: the results showed the insufficient preparation of the professionals on the nursing theories and models which constitute a theoretical and scientific basis for interventions with newborn patients located in the Neonatology room.
Assuntos
Educação Médica , Educação em Enfermagem , Educação Profissionalizante , Tutoria , AprendizagemRESUMO
Fundamento: la colaboración cubana demanda perfeccionar el dominio del idioma inglés entre aquellos profesionales de la salud que cumplen misiones internacionalistas. Objetivo: exponer los resultados de una estrategia metodológica para perfeccionar el dominio del idioma inglés en los profesionales de la salud que cumplen misiones internacionalistas. Métodos: se realizó un estudio descriptivo con diseño transversal en la Universidad de Ciencias Médicas de Villa Clara durante el período enero 2019 hasta junio 2021. Se aplicaron métodos teóricos, empíricos para la fundamentación de la investigación y recogida de información y matemático-estadísticos; la información obtenida se presentó en tablas con valores absolutos y relativos. Resultados: durante el año 2019 concluyeron 18 cursos, con 128 graduados, de ellos 61 con nivel A2. En el año 2020 culminó el Diplomado de Inglés para profesionales procedentes de Brasil con 55 participantes, la mayoría con nivel B1. También se graduaron 192 profesionales en cursos de inglés, el 63,54 % eran médicos, la mayoría de ellos especialistas en Medicina General Integral. Predominó el nivel B1 con 63 cursistas. Al concluir el mes de junio 2021 estaban participando en cursos de inglés 70 profesionales, la mayoría médicos (70.0 %) Conclusiones: se cumplió la capacitación programada para este periodo respondiendo a las necesidades de aprendizaje identificadas, se certificaron los graduados y se cumplimentaron los convenios de preparación a internacionalistas entre la Universidad de Ciencias Médicas Villa Clara y el Departamento Provincial de Colaboración.
Background: the Cuban collaboration demands improving the command of the English language among those health professionals who fulfill internationalist missions. Objective: to present the results of a methodological strategy to improve the command of the English language in health professionals who fulfill internationalist missions. Methods: a descriptive study with a cross-sectional design was carried out at Villa Clara University of Medical Sciences from January 2019 to June 2021. Theoretical and empirical methods were applied for the foundation of the research and information collection, and mathematical-statistical methods; the information obtained was presented in tables with absolute and relative values. Results: during the year 2019, 18 courses were completed, with 128 graduates, 61 of them with A2 level. In 2020, the Diploma in English for professionals from Brazil was completed with 55 participants, most with B1 level. 192 professionals also graduated in English courses, 63.54 % were doctors, most of them specialists in Comprehensive General Medicine. Level B1 predominated with 63 trainees. At the end of June 2021, 70 professionals were participating in English courses, most of them doctors (70.0 %) Conclusions: the training programmed for this period was fulfilled, responding to the identified learning needs, the graduates were certified and the internationalist preparation agreements between the Villa Clara University of Medical Sciences and the Provincial Department of Collaboration were fulfilled.
Assuntos
Estratégias de Saúde , Educação Médica , Educação Profissionalizante , Tutoria , Idioma , AprendizagemRESUMO
Fundamento: los estudios pedagógicos han mostrado que existen dificultades en el funcionamiento de los colectivos de año; estos constituyen un eslabón fundamental para el desarrollo del trabajo metodológico en las universidades. Objetivo: diagnosticar las dificultades que se presentan en el funcionamiento de los colectivos de año. Métodos: se realizó una investigación descriptiva con enfoque cualitativo, en la Facultad de Tecnología Enfermería de la Universidad de Ciencias Médicas de Villa Clara entre octubre de 2021 y abril de 2022. Se utilizaron métodos teóricos: análisis-síntesis, inductivo-deductivo e histórico-lógico; empírico: análisis documental, observación, encuestas; y matemático-estadísticos para el análisis de los datos encontrados. Resultados: se constató que no todos los profesores principales de año dirigían su labor de dirección metodológica a la coordinación, asesoría y control de los profesores guías, tutores y el colectivo de profesores del año, además, no en todos los colectivos se analizaba un tema de carácter metodológico que satisficiera las necesidades de los implicados, existían dificultades en el conocimiento de los documentos que deben conservar como profesores principales de año, en sentido general, en las actas se evidencian dificultades en su redacción y no siempre se tomaron acuerdos medibles y alcanzables para resolver las dificultades del año académico. Conclusiones: los resultados exhibidos en esta investigación demostraron que existen dificultades en el colectivo de año, encargados de llevar el trabajo metodológico en este nivel organizativo e insuficiencias en el dominio de las funciones del profesor principal de año.
Background: pedagogical studies have shown that there are difficulties in the functioning of the teaching staff of each year; they constitute a fundamental link for the development of methodological work in universities. Objective: to diagnose the difficulties that arise in the functioning of the teaching staff of each year. Methods: a descriptive research with a qualitative approach was carried out in the Faculty of Nursing Technology at the University of Medical Sciences in Villa Clara between October 2021 and April 2022. Analysis-synthesis, inductive-deductive and historical- logical approaches were applied as theoretical methods; documentary analysis, observation and surveys as empirical ones; and mathematical-statisticians were used for the analysis of the data found. Results: we verified that not all the main teachers of each year directed their methodological work to the coordination, advice and control of the guide teachers, tutors and the teaching staff; in addition, not in all the groups an issue of a methodological nature that satisfies the needs of those involved was analyzed. There were difficulties in knowing the documents that must be kept as main teachers of the year, in a general sense, the minutes show difficulties in their writing and measurable and achievable agreements were not always reached to solve the difficulties of the academic year. Conclusions: the results exhibited in this research showed that there are difficulties in the teaching staff of each year in charge of carrying out the methodological work at this organizational level as well as insufficiencies in the mastery of the functions of the main teacher of the year.