Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
1.
Theriogenology ; 225: 162-171, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38805998

RESUMEN

Fourier harmonic analysis (FHA) is a robust method for identification of minute changes in sperm nuclear shape that are indicative of reduced fertility. The current study was designed to develop a fertility prediction model for Nili-Ravi buffalo bulls through FHA of sperm. In experiment I, FHA technique was standardized, average sperm nuclear perimeter was measured and sperm nuclear shape plot of buffalo bull was constructed. Sperm of buffalo bulls (n = 10) were stained with YOYO-1 and Hoechst-33342 to differentiate live and dead, and digital images were captured using phase contrast and fluorescent microscopy. The images were analyzed by ImageJ software and 100 sperm/bull were evaluated. The results are described as mean ± SEM values of mean harmonic amplitude (mharm), skewness harmonic amplitude (skharm), kurtosis harmonic amplitude (kurharm) and variance harmonic amplitude (varharm) at Fourier frequencies 0-5 along with the cartesian and polar coordinate plots of buffalo bull sperm. In experiment II, a fertility prediction model was developed based on FHA of buffalo bull sperm. Semen samples of low (n = 6), medium (n = 3) and high (n = 8) fertility bulls were investigated for FHA of sperm and harmonic amplitudes (HA) were generated. Firstly, to determine if live and dead sperm population have unique nuclear shape distribution; the mean, skewness, kurtosis and variance HA 0-5 of 1700 live and 1294 dead spermatozoa of 17 bulls were evaluated. T-test signified a difference in the mharm0 (2.363 ± 0.01 vs. 2.439 ± 0.02), skharm0 (-0.0002 ± 0.07 vs. -0.266 ± 0.09), kurharm0 (-0.156 ± 0.07 vs. 0.260 ± 0.18), kurharm2 (0.142 ± 0.11 vs. 1.031 ± 0.32) and varharm4 (0.109 ± 0.00 vs. 0.082 ± 0.00) of live vs. dead sperm population (p < 0.05). Therefore, 100 live sperm/bull were further evaluated for mean, skewness, kurtosis and variance HA 0-5 values among high (n = 6) and low-fertility (n = 6) groups. Results of T-test showed higher values of mharm2 (0.739 ± 0.01 vs. 0.686 ± 0.00), mharm4 (0.105 ± 0.001 vs. 0.007 ± 0.001), and skharm0 (0.214 ± 0.109 vs. -0.244 ± 0.097) in high vs. low-fertility group (p < 0.05). In next step, five significantly different combinations of discriminant measures between high and low-fertility groups were obtained by discriminant analysis. In conclusion, mharm4, skharm0 and varharm2 correctly identified 91.7 % of bulls into their respective fertility groups, and upon cross validation the value of the canonical correlation was 0.928.


Asunto(s)
Búfalos , Fertilidad , Análisis de Semen , Espermatozoides , Animales , Masculino , Búfalos/fisiología , Espermatozoides/fisiología , Fertilidad/fisiología , Análisis de Semen/veterinaria , Análisis de Semen/métodos , Análisis de Fourier
2.
Reprod Domest Anim ; 58(7): 946-954, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37133263

RESUMEN

Most embryo losses occur in the first trimester of pregnancy in cows and include losses following embryo transfer. There is a resulting negative economic impact on cattle production systems when this occurs. Cellular and molecular mechanisms behind the maternal immune response to the growing embryo have not been fully characterized. The objective of this study was to examine the gene expression profiles of peripheral white blood cells (PWBCs) from pregnant cows 21 days after an embryo was transferred, and cows that were treated equally but lost the embryo. Specifically, we obtained and compared the transcriptome of PWBC from heifers that became pregnant at day 21 (N = 5) or failed to become pregnant after the embryo transfer (N = 5). Sequencing data can be accessed by Gene Expression Omnibus (GEO) with the accession number GSE210665. A total of 13,167 genes were evaluated for differential expression between groups. A total of 682 genes showed differential expression (p-value <.01), 302 genes were up-regulated while 380 were down-regulated due to pregnancy. The most significant genes were COL1A2, H2AC18, HTRA1, MMP14, CD5L, ADAMDEC1, MYO1A and RPL39, among others. Most of the significant genes are related to the up-regulation of inflammatory chemokine activity and immune defence response. Our findings extend the current knowledge that pregnancy alters the PWBC by promoting immune tolerance, cell chemotaxis, blood coagulation, angiogenesis, inflammatory response, cell adhesion and cytokine secretion. Our data suggest that pregnancy and ectoparasites could trigger poorly described genes in PWBC of cows, and a few previously escribed genes, such as IFI44. These results could shed light on the genes and mechanisms that promote tolerance to pregnancy and allow survival of the developing embryo.


Asunto(s)
Transferencia de Embrión , Transcriptoma , Embarazo , Bovinos/genética , Animales , Femenino , Transferencia de Embrión/veterinaria , Transferencia de Embrión/métodos , Leucocitos , Tolerancia Inmunológica/genética
3.
Life (Basel) ; 13(2)2023 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-36836732

RESUMEN

Pleural space infections have been a well-recognized clinical syndrome for over 4000 years and continue to cause significant morbidity and mortality worldwide. However, our collective understanding of the causative pathophysiology has greatly expanded over the last few decades, as have our treatment options. The aim of this paper is to review recent updates in our understanding of this troublesome disease and to provide updates on established and emerging treatment modalities for patients suffering from pleural space infections. With that, we present a review and discussion synthesizing the recent pertinent literature surrounding the history, epidemiology, pathophysiology, diagnosis, and management of these challenging infections.

4.
J Anim Sci ; 1012023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36850045

RESUMEN

The objective of this work was to determine if specific circulating microRNA (miRNA) differed due to pregnancy status in heifers. Blood samples were collected from heifers 21 d after receiving an in vitro-produced embryo. Pregnancy status was diagnosed 21 d after embryo transfer, equivalent to day 28 of gestation, with rectal ultrasonography. Blood samples from 10 pregnant and 10 nonpregnant heifers were then evaluated for miRNA expression. There were five different miRNAs quantified using delta-delta Ct and qPCR methodology. These miRNAs had previously been associated with early pregnancy in cattle. The miRNA Let-7d-5p was decreased in nonpregnant as compared to pregnant females (P < 0.05). There were no changes in 16-5p, 16-1-3p, 16-2-3p, and 26a-5p associated with pregnancy (P > 0.05). Results demonstrate an opportunity to identify and study the differential expression of miRNAs from the blood of pregnant cows. The Let-7d-5p miRNA is a potential early pregnancy marker and is critical to better understand the early relationships of the cellular and molecular interactions of the cow and embryo.


MicroRNAs are critical molecules in cell homeostasis and can bind their target in the cellular cytoplasm by miRNA recognition of the 3ʹUTR sequence in the messenger RNA (mRNA) or other RNAs and inhibiting the mRNA translation. This molecular mechanism is called gene silencing. These miRNAs are stable in blood and can be useful as biomarkers of early pregnancy in the bovine. We demonstrated a decrease in the miRNAs, Let-7d-5p, at day 21 post embryo transfer for nonpregnant samples contrasted with pregnant blood samples (P < 0.05). This research opens new methodologies to study and understand miRNAs circulating in blood of pregnant vs. nonpregnant cows at early stages.


Asunto(s)
MicroARNs , Embarazo , Bovinos/genética , Femenino , Animales , MicroARNs/metabolismo , Embrión de Mamíferos , Perfilación de la Expresión Génica/veterinaria
5.
Disaster Med Public Health Prep ; 16(1): 321-327, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-32907684

RESUMEN

Successful management of an event where health-care needs exceed regional health-care capacity requires coordinated strategies for scarce resource allocation. Publications for rapid development, training, and coordination of regional hospital triage teams to manage the allocation of scarce resources during coronavirus disease 2019 (COVID-19) are lacking. Over a period of 3 weeks, over 100 clinicians, ethicists, leaders, and public health authorities convened virtually to achieve consensus on how best to save the most lives possible and share resources. This is referred to as population-based crisis management. The rapid regionalization of 22 acute care hospitals across 4500 square miles in the midst of a pandemic with a shifting regulatory landscape was challenging, but overcome by mutual trust, transparency, and confidence in the public health authority. Because many cities are facing COVID-19 surges, we share a process for successful rapid formation of health-care care coalitions, Crisis Standard of Care, and training of Triage Teams. Incorporation of continuous process improvement and methods for communication is essential for successful implementation. Use of our regional health-care coalition communications, incident command system, and the crisis care committee helped mitigate crisis care in the San Diego and Imperial County region as COVID-19 cases surged and scarce resource collaborative decisions were required.


Asunto(s)
COVID-19 , COVID-19/epidemiología , COVID-19/terapia , Humanos , Pandemias , Salud Pública , Asignación de Recursos , Triaje/métodos
6.
J Clin Transl Sci ; 5(1): e137, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34367681

RESUMEN

Implementation of clinically useful research discoveries in the academic environment is challenged by limited funding for early phase proof-of-concept studies and inadequate expertise in product development and commercialization. To address these limitations, the National Institutes of Health (NIH) established the National Centers for Accelerated Innovations (NCAI) program in 2013. Three centers competed successfully for awards through this mechanism. Here, we present the experience of one such center, the Boston Biomedical Innovation Center (B-BIC), and demonstrate its remarkable success at the translation of innovations to clinical application and commercialization, as well as skills development and education.

7.
Curr Neurol Neurosci Rep ; 21(7): 32, 2021 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-33956247

RESUMEN

PURPOSE OF REVIEW: Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial upper airway obstruction during sleep. Studies indicate that OSA is an independent risk factor for cognitive decline in older patients. The purpose of this paper is to critically review the recent literature on the cognitive effects of untreated OSA and the benefits of treatment across cognitive domains. RECENT FINDINGS: OSA's greatest impact appears to be on attention, vigilance, and information processing speed. Furthermore, the presence of OSA seems to have a significant impact on development and progression of mild cognitive impairment (MCI). Impact of OSA treatment, particularly with CPAP, appears to mitigate and slow the rate of cognitive decline and may reduce the risk of dementia. Larger properly controlled studies, of a prospective nature, are required to further elucidate the degree of treatment effect. More studies are needed on other treatments for OSA such as oral mandibular devices and hypoglossal nerve stimulation.


Asunto(s)
Disfunción Cognitiva , Apnea Obstructiva del Sueño , Cognición , Disfunción Cognitiva/etiología , Disfunción Cognitiva/terapia , Presión de las Vías Aéreas Positiva Contínua , Humanos , Estudios Prospectivos , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/terapia
9.
Front Genet ; 11: 1019, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33173528

RESUMEN

Seasonal reproductive inefficiency is still observed in modern swine facilities. We previously reported global placental methylation activity was reduced from summer breedings and tended to be less from semen collected during cooler periods. The objective of the current study was to evaluate chromatin modification marks within swine placenta in relationship to breeding season, semen collection season, and semen storage. White composite gilts were artificially inseminated in August or January using single-sire semen that was collected during warm or cool periods and stored as either cryopreserved or cooled-extended. Gilts were harvested 45 days post-breeding, and placental samples from the smallest, average, and largest fetus in each litter were collected and stored at -80°C until RNA extraction. An RT2 Profiler assay featuring 84 known chromatin modification enzyme targets was performed using placental RNA pooled by litter. Real-time quantitative polymerase chain reaction results were analyzed using the MIXED procedure, and P-values were Hochberg corrected using the MULTTEST procedure in SAS. The complete model included the fixed effects of breeding season (winter or summer), semen collection season (cool or warm), semen storage (cooled-extended or cryopreserved), interactions; boar as repeated effect; and plate as random effect. If interactions were not significant, only the main effects were tested. The genes, ATF2, AURKA, and KDM5B, were different (P < 0.05) by interaction of breeding season, semen collection season, and semen storage. In general, the greatest (P < 0.05) expression was in placentas derived from summer breedings. Expression of AURKA was also influenced by semen collection and storage. Expression of placental KDM5B from winter breedings was also greater (P < 0.05) from semen collected during cool periods. Placental expressions of ASH2L, DNMT3B, ESCO1, HDAC2, ING3, KDM6B, MYSM1, and SMYD3 were greater (P < 0.05) from summer breedings. Increased expressions of known chromatin modification genes, from placentas derived from summer breedings, are likely responsible for differences in gene transcription between summer- or winter-derived placentas.

10.
Chest ; 158(1): 212-225, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32289312

RESUMEN

Public health emergencies have the potential to place enormous strain on health systems. The current pandemic of the novel 2019 coronavirus disease has required hospitals in numerous countries to expand their surge capacity to meet the needs of patients with critical illness. When even surge capacity is exceeded, however, principles of critical care triage may be needed as a means to allocate scarce resources, such as mechanical ventilators or key medications. The goal of a triage system is to direct limited resources towards patients most likely to benefit from them. Implementing a triage system requires careful coordination between clinicians, health systems, local and regional governments, and the public, with a goal of transparency to maintain trust. We discuss the principles of tertiary triage and methods for implementing such a system, emphasizing that these systems should serve only as a last resort. Even under triage, we must uphold our obligation to care for all patients as best possible under difficult circumstances.


Asunto(s)
Infecciones por Coronavirus , Pandemias , Neumonía Viral , Asignación de Recursos/organización & administración , Triaje/organización & administración , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/terapia , Cuidados Críticos/métodos , Humanos , Neumonía Viral/epidemiología , Neumonía Viral/terapia , Salud Pública/ética , Salud Pública/métodos , Salud Pública/normas , SARS-CoV-2 , Capacidad de Reacción/ética , Capacidad de Reacción/organización & administración
11.
Mil Med ; 185(5-6): e864-e869, 2020 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-31925432

RESUMEN

INTRODUCTION: Lung cancer is the leading cause of cancer death among men and women, accounting for more fatalities than colon, breast, and prostate cancers combined. Smoking causes about 85% of all lung cancers in the United States and is the single greatest risk factor. In 2013, the US Preventive Services Task Force (USPSTF) published initial guidelines for low-dose computed tomography lung cancer screening (LCS) among patients 55-80 years old, with a 30-pack-year history, who are current smokers or who quit within the previous 15 years. Smoking prevalence is higher among military personnel compared to the civilian population, demonstrating a need for vigilant screening. MATERIALS AND METHODS: A retrospective review of Naval Medical Center San Diego's (NMCSD) LCS data was conducted to examine screening numbers, lung cancer rates, and initial analysis of screening results. Patients were referred for screening if they met the USPSTF criteria. Between September 2013 and September 2018, 962 patients underwent LCS. A total of 1758 examinations were performed, including follow-up and annual surveillance examinations. The American College of Radiology's Lung CT Screening Reporting and Data System (Lung-RADS) was used to classify lung nodules' risk for malignancy. RESULTS: On this initial analysis, 42 enrolled patients received the diagnosis of lung cancer detected by screening. The initial calculated lung cancer rate is 4.4% (42/962) over the 5-year reporting period. The lung cancer rate among those patients with a Lung-RADS score of 3 or 4 was 31% (42/135). Thirty-seven patients were classified as having non-small cell lung cancer (NSCLC), while five were classified as having small cell lung cancer. Of the 37 NSCLC patients, 76% (28/37) were diagnosed at stage I and II, 11% (4/37) were diagnosed at stage III, and 13% (5/37) were diagnosed at stage IV. The total number of years a person smoked was a significant risk factor (P = 0.004), but not pack-years a person smoked (P = 0.052). CONCLUSIONS: These preliminary results demonstrate the success of a Military Treatment Facility (MTF)-based LCS Program in the detection of early stage lung cancer. Earlier stage detection may result in better health outcomes for affected patients. In the population studied, duration of smoking proved to be more significant than pack-years in predicting lung cancer risk. These results validate the newly dedicated resources and continued efforts to strengthen the LCS program at NMCSD and across MTFs.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Personal Militar , Anciano , Anciano de 80 o más Años , Detección Precoz del Cáncer , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiología , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Estados Unidos/epidemiología
12.
Crit Care Clin ; 35(4): 563-573, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31445605

RESUMEN

A health care facility must develop a comprehensive disaster plan that has a provision for critical care services. Mass critical care requires surge capacity: augmentation of critical care services during a disaster. Surge capacity involves staff, supplies, space, and structure. Measures to increase critical care staff include recalling essential personnel, using noncritical care staff, and emergency credentialing of volunteers. Having an adequate supply chain and a cache of critical care supplies is essential. Virtual critical care or tele-critical care can augment critical care capacity by assisting with patient monitoring, specialized consultation, and in pandemics reduces staff exposure.


Asunto(s)
Cuidados Críticos , Planificación en Desastres , Cuidados Críticos/organización & administración , Planificación en Desastres/organización & administración , Desastres , Fuerza Laboral en Salud/organización & administración , Humanos , Incidentes con Víctimas en Masa
13.
Crit Care Clin ; 35(4): 619-631, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31445609

RESUMEN

Radiation accidents are rare, but can produce large numbers of casualties with predictable patterns of injury. Casualties may suffer from a wide range of radiation exposures. Triage based on presence or absence of conventional injuries and an accurate assessment of radiation dose based on event history, symptoms, and laboratory testing, is critical. Treatment of acute radiation syndrome is supportive: including fluids, antibiotics, blood products, colony-stimulating factors, and stem cell or bone marrow transplantation. Care of radiation-injured patients with conventional trauma or burns needs to be modified to account for adverse effects of radiation on wound healing and susceptibility to infections.


Asunto(s)
Planificación en Desastres , Traumatismos por Radiación/terapia , Liberación de Radiactividad Peligrosa , Cuidados Críticos/métodos , Descontaminación , Humanos , Traumatismos por Radiación/diagnóstico , Traumatismos por Radiación/epidemiología
14.
Theriogenology ; 137: 75-81, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31204016

RESUMEN

Continuous progress in nanoscience has allowed the synthesis of various nanoscale particles, known as nanoparticles or nanomaterials which, by harnessing unique physico-chemical properties, are crucial for multiple bio-applications. Despite the revealed toxicity (nanotoxicity) of nanoparticles in various in vitro and in vivo studies, their careful design for biocompatibility and effective interactions with single-celled and multi-cellular organisms has permitted their use in several fields of research and biomedicine. The various nanoparticles synthesized and applied in the veterinary sciences, including reproductive biology, have shown potential to influence routine practices in animal production systems. These include post-collection manipulation of semen and the protection of high-quality spermatozoa to extend their preservation, and to improve sperm-related biotechnologies such as sperm-mediated gene transfer, sperm sorting, sex-sorting, and cryopreservation. Therefore, the application of nanotechnology-based tools to semen may enhance assisted reproductive technologies for biomedical applications and improve economic productivity for farmers. Here, we review the efficacy of available techniques and emerging tools of nanotechnology that might be useful for further selection of high quality boar spermatozoa and productivity improvement.


Asunto(s)
Nanopartículas , Espermatozoides/fisiología , Animales , Biotecnología/métodos , Criopreservación/veterinaria , Fertilidad , Masculino , Porcinos
15.
Mol Reprod Dev ; 86(4): 465-475, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30767330

RESUMEN

Epigenetics includes the study of external factors that can influence the expression of genes by altering the accessibility of DNA through methylation. To investigate the epigenetic influence of season, sperm head shape, and semen storage on placental and fetal tissues, pregnancies were generated in the summer or winter using boar semen from either least or most sperm head shape change, collected during cool or warm seasons, and stored as cooled-extended or cryopreserved. The lowest (p < 0.05) ratios of 5-methylcytosine to 5-hydroxymethylcytosine activity (5mC:5hmC) in fetal liver were from summer breedings and in placental tissues from winter breedings. The relative expression of placental CDH1 tended ( p < 0.10) to be greater in placenta generated from cryopreserved semen or semen collected during cool periods. The relative expression of placental GNAS was affected ( p < 0.05) by the interaction of breeding and semen collection seasons. Cryopreserved semen increased ( p < 0.05) the placental relative expression of GNAS. Placental MEST and RHOBTB3 tended ( p < 0.10) to have a greater relative expression from pregnancies generated using semen collected during cool periods used during winter breedings. Within fetal liver, the relative expression of GNAS and HGF was greater ( p < 0.05) from winter breedings. Interaction of winter breedings and least sperm head shape change tended ( p < 0.10) to have the greatest fetal liver expression of CDH1. Seasonality of semen collection, breeding, and the effect on sperm head shape change had an influence on the expression of genes with known differentially methylated regions or response to methylation activity from embryonic and extraembryonic tissues.


Asunto(s)
Cruzamiento , Metilación de ADN , Epigénesis Genética , Feto/embriología , Hígado/embriología , Placenta/metabolismo , Estaciones del Año , Preservación de Semen , Cabeza del Espermatozoide/metabolismo , Motilidad Espermática , Animales , Femenino , Feto/citología , Hígado/citología , Masculino , Placenta/citología , Embarazo , Porcinos
16.
Curr Opin Biomed Eng ; 11: 145-148, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33178901

RESUMEN

As the healthcare system evolves from a centralized, hospital- and office-based model to an emphasis on patient-centric care delivered in decentralized settings from the community and/or home to low resource settings domestically and internationally, some Point-of-Care Technologies (POCT) have become important and others may soon become important in facilitating care. These portable diagnostic and monitoring devices enable moving care closer to the patient. We review recent developments in a national model to accelerate the development of POCT, specifically the Point-of-Care Technology Research Network (POCTRN), comprising a multi-center scientific network supported by a coordinating center. We summarize the history of the Network, and then describe the primary objectives and key activities of the Network and highlight the role of a new coordinating center providing administrative and infrastructure support. POCTRN is committed to building evidence-based best practices for high-quality translation and commercialization in biomedical engineering to maximize clinical impact of Point-of-Care Technologies.

17.
J Anim Sci ; 96(7): 2952-2970, 2018 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-29684167

RESUMEN

The study of reproductive physiology in domestic ruminants has progressed from the whole animal to the molecular level in an amazingly short period of time. The volume of information on this subject is enormous; therefore, we have focused on domestic ruminants, with an emphasis on cattle. To date, artificial insemination (AI) is perhaps the most powerful technique that reproductive physiologists and geneticists have provided the livestock industry for genetic improvement. Early efforts to establish AI as a tool were initiated in Russia around 1899 and since that time major advances in methods of semen collection, evaluation of male fertility, cryopreservation of sperm, sex-sorted semen, and estrous cycle control have occurred. The preceding advances not only led to the widespread use of AI, but also contributed to our fundamental understanding of ovulation control, timing of insemination, gamete biology, and cryopreservation. In regards to anestrus, our understanding of the concept of neuroendocrine control of the pituitary gland and the role of steroid feedback led to the Gonadostat Theory, which proposes that onset of puberty is due to a decrease in the negative feedback of gonadal steroids over time. Subsequent studies in prepuberal and postpartum sheep and cattle established that a short luteal phase frequently precedes the first normal length cycle that is accompanied by estrous expression. This observation led to the common practice of treating prepuberal heifers and anestrous postpartum cows with a short-term progestin treatment (e.g., Controlled Internal Drug Release) to induce normal estrous cycles. In domestic ruminants, fertilization rate is high (85% to 95%); however, significant embryonic mortality before or around the time of maternal recognition of pregnancy (MRP) reduces the pregnancy rate to a single breeding. Significant effort has been directed at determining the time of MRP, the signal for MRP, as well as elucidating the physiological, cellular, and molecular dialogue between the conceptus and uterine environment. Advancements have now led us to the ability to edit the genome to alleviate disease and possibly improve production traits. In summary, major advancements in our understanding of reproductive biology have stemmed from efforts to establish the AI and embryo transfer technique and reduce the negative impact of anestrus and embryonic mortality in domestic ruminants.


Asunto(s)
Bovinos/fisiología , Inseminación Artificial/historia , Reproducción , Ovinos/fisiología , Animales , Cruzamiento/historia , Criopreservación/historia , Criopreservación/veterinaria , Transferencia de Embrión/historia , Transferencia de Embrión/veterinaria , Ciclo Estral , Estro , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Inseminación Artificial/veterinaria , Masculino , Ovulación , Periodo Posparto , Embarazo , Índice de Embarazo , Rumiantes , Maduración Sexual
18.
Gastroenterology ; 154(8): 2064-2067.e3, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29481778

RESUMEN

There are few data on the effects of methotrexate on reproductive capacity in men with inflammatory bowel diseases (IBDs). We performed a case-control study to determine the effects of methotrexate on sperm quality and genetic integrity. We compared sperm samples from 7 men with IBD who had been exposed to methotrexate for at least 3 months with sperm samples collected from 1912 age-matched men at fertility centers (controls) where sperm parameters would be expected to be worse than those of the general population. Sperm were evaluated by basic semen analysis and advanced sperm integrity testing. In samples from men with IBD, all basic semen analysis parameters were within normal limits. However, these samples had reduced sperm integrity, based on significant increases in levels of DNA fragmentation and damage from oxidative stress compared with controls. Our findings indicate that methotrexate can reduce DNA integrity in sperm and cause damage via oxidative stress.


Asunto(s)
Fragmentación del ADN/efectos de los fármacos , Antagonistas del Ácido Fólico/efectos adversos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Metotrexato/efectos adversos , Espermatozoides/efectos de los fármacos , Adulto , Estudios de Casos y Controles , ADN/genética , Fertilidad/efectos de los fármacos , Humanos , Masculino , Estrés Oxidativo/efectos de los fármacos , Análisis de Semen , Espermatozoides/metabolismo , Adulto Joven
20.
Mol Reprod Dev ; 84(9): 969-978, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28696579

RESUMEN

Seasonal infertility is a limiting factor in boar fertility, and is increasingly important as climate changes. Spermatogenesis in the boar produces 256 spermatozoa per type A1 spermatogonium, but the process is inefficient such that only 10-30% of these potential spermatozoa are actually produced. Heat further impacts spermatogenesis by reducing the number of specific germ cells produced while increasing the fraction of abnormal sperm. Early studies used whole-animal exposure to simulate seasonal exposure to heat under production settings, but this approach is associated with many confounding factors that make assessment of the mechanisms of heat-induced damage to spermatogenesis difficult. Scrotal insulation provides a better model to investigate the mechanisms and potential mitigation strategies of heat-induce damage. For example, scrotal insulation helped identify a link between short-term heat stress and damage to meiotic germ cells. This outcome is likely due to changes in the integrity of the blood-testis barrier, which induce apoptosis, autophagy and DNA damage in the germ cells. Further understanding how heat damages spermatogenesis, and whether or not this can be repaired, are crucial to mitigating heat effects on boars in production settings.


Asunto(s)
Trastornos de Estrés por Calor/metabolismo , Infertilidad Masculina/metabolismo , Escroto/metabolismo , Estaciones del Año , Espermatogénesis , Espermatozoides/metabolismo , Animales , Trastornos de Estrés por Calor/patología , Trastornos de Estrés por Calor/fisiopatología , Infertilidad Masculina/patología , Infertilidad Masculina/fisiopatología , Masculino , Escroto/patología , Escroto/fisiopatología , Espermatozoides/patología , Porcinos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...