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The thermophilic cellulase Cel5a from Fervidobacterium nodosum (FnCel5a) was conjugated with neutral, cationic, and anionic polymers of increasing molecular weights. The enzymatic activity toward an anionic soluble cellulose derivative, thermal stability, and functional chemical stability of these bioconjugates were investigated. The results suggest that increasing polymer chain length for polymers compatible with the substrate enhances the positive impact of polymer conjugation on enzymatic activity. Activity enhancements of nearly 100% were observed for bioconjugates with N,N-dimethyl acrylamide (DMAm) and N,N-dimethyl acrylamide-2-(N,N-dimethylamino)ethyl methacrylate (DMAm/DMAEMA) due to proposed polymer-substrate compatibility enabled by potential noncovalent interactions. Double conjugation of two functionally distinct polymers to wild-type and mutated FnCel5a using two conjugation methods was achieved. These doubly conjugated bioconjugates exhibited similar thermal stability to the unmodified wild-type enzyme, although enzymatic activity initially gained from conjugation was lost, suggesting that chain length may be a better tool for bioconjugate activity modulation than double conjugation.
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Celulase , Polímeros , Acrilamidas , Celulase/química , Celulase/genética , Celulose , Metacrilatos/química , Peso Molecular , Polímeros/químicaRESUMO
A thermophilic cellulase, FnCel5a, from Fervidobacterium nodosum was conjugated with various functional polymers including cationic, anionic, and strongly and weakly hydrogen bonding polymers. The activity of FnCel5a toward a high-molecular-weight carboxymethyl cellulose substrate was enhanced by polymer conjugation. Activity enhancements of 50% or greater observed for acrylamide and mixed N,N-dimethyl acrylamide-2-(N,N-dimethylamino)ethyl methacrylate polymers, suggesting that the greatest enhancements were caused by polymers capable of noncovalent interactions with the substrate. The conjugates were found to have nearly identical thermodynamic stability to the native enzyme, as assessed by free energy (ΔG), enthalpy (ΔH), and entropy (TΔS) parameters extracted from differential scanning fluorimetry. Polymers tended to confer comparable tolerance to high concentrations of dimethylformamide, with longer polymers typically enabling higher activity relative to shorter polymers. The new FnCel5a conjugates represent an advance in the production of cellulases that maintain activity at high temperatures or in the presence of denaturing organic solvents.
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Celulases/química , Celulases/metabolismo , Polímeros/química , Temperatura , Entropia , Estabilidade Enzimática , Metacrilatos/química , Modelos Moleculares , Polimerização , Conformação ProteicaRESUMO
There is a reported 5-20 % incidence of extracorporeal membrane oxygenation (ECMO) following stage I palliation for hypoplastic left heart syndrome (HLHS). This study compares the interstage mortality of HLHS patients supported with ECMO (HLHS-ECMO) to those who were not supported with ECMO (HLHS-nECMO) using the National Pediatric Cardiology Quality Improvement Initiative database. Patients with HLHS who survived to hospital discharge after stage I palliation were analyzed. HLHS-ECMO patients were compared to HLHS-non-ECMO patients with respect to demographics, surgical variables, and interstage survival. A total of 931 patients were identified in the database. Sixty-six (7.1 %) patients were supported with ECMO during their stage I palliation admission. There were no statistically significant differences between the groups with respect to demographics or anatomic subtype. HLHS-ECMO patients were more likely to have a preoperative risk factor identified (62 vs. 48 %, p = 0.03) or require ECMO prior to stage I palliation (3 vs. 0.5 %, p = 0.03). HLHS-ECMO patients had a significantly higher incidence of death or transplant versus the HLHS-nECMO group (18 vs. 9 %, p = 0.03). Despite survival to discharge, patients with HLHS requiring ECMO after their palliation continue to have an increased risk of death/cardiac transplant versus patients that do not require ECMO. ECMO use is likely a marker for a high-risk patient group. These patients may benefit from closer follow-up during the interstage period.
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Oxigenação por Membrana Extracorpórea/métodos , Síndrome do Coração Esquerdo Hipoplásico/mortalidade , Procedimentos de Norwood/métodos , Cuidados Paliativos/métodos , Bases de Dados Factuais , Feminino , Humanos , Síndrome do Coração Esquerdo Hipoplásico/terapia , Lactente , Recém-Nascido , Masculino , Procedimentos de Norwood/efeitos adversos , Alta do Paciente , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: Femoral version measurement techniques based on magnetic resonance imaging (MRI) studies have been developed as an alternative to the high levels of ionizing radiation associated with computed tomography (CT)-based methods. Previous studies have not evaluated the reliability, repeatability, and accuracy of MRI-based femoral version measurements in an adolescent population. METHODS: Subjects who underwent MRI and CT studies for clinical suspicion of hip pain secondary to hip dysplasia or femoroacetabular impingement between 2011 and 2013 were identified. Rapid sequence femoral version images were obtained from MRI Hip dGEMRIC and/or postarthrogram studies. Femoral version images were also obtained from bilateral CT lower extremity, without contrast, studies. Measurements were made by 1 fellowship-trained, pediatric hip preservation attending surgeon, 2 pediatric orthopaedic surgical fellows, and 1 fellowship-trained musculoskeletal radiologist on 2 separate occasions. Linear mixed models were used to estimate the reliability and repeatability associated with CT-based and MRI-based measurements (intraclass correlation coefficients) and to estimate the agreement (CT-MRI) between the 2 techniques. RESULTS: The mean age of 36 subjects was 15.4 years (±4.1 y). Interrater reliability was 0.91 (95% CI, 0.86-0.95) for the CT technique compared with 0.90 (95% CI, 0.86-0.94) for the rapid sequence MRI technique. Intrarater reliability for the CT technique was 0.96 (95% CI, 0.91-0.98) compared with 0.95 (95% CI, 0.90-0.97) for the MRI technique. The agreement between the MRI-based and CT-based techniques (bias: 1.9 degrees, limits of agreement: -11.3 to 14.9 degrees) was similar to the agreement between consecutive MRI measurements (bias: 0.4 degrees, limits of agreement: -7.8 to 8.6 degrees) as well as consecutive CT measurements (bias: 0.5 degrees, limits of agreement: -8.8 to 9.9 degrees). CONCLUSIONS: The interrater and intrarater reliability and repeatability estimates (intraclass correlation coefficient values) associated with both techniques was excellent (>0.90). Acquirement of axial images at the pelvis and knee during MRI for investigation of adolescents with hip pain allows for reliable measurement of femoral version. LEVEL OF EVIDENCE: Level II-diagnostic study.
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Mau Alinhamento Ósseo/diagnóstico por imagem , Fêmur/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Mau Alinhamento Ósseo/complicações , Criança , Feminino , Impacto Femoroacetabular/complicações , Impacto Femoroacetabular/diagnóstico por imagem , Luxação do Quadril/complicações , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
Endometritis was rated as the third most common medical problem encountered in adult horses in North America. It is the leading cause of subfertility in broodmares and is a major contributor to economic loss in the horse breeding industry, with pregnancy rates reported to be as low as 21% in mares with severe endometritis. Endometritis may be categorized as: endometrosis (chronic degenerative endometritis), acute, chronic, active, dormant, subclinical, clinical, and persistent post-breeding. These classifications are not mutually exclusive, and mares may change categories within breeding seasons or estrous cycles or may fit in multiple classifications. This chapter will focus on discussing etiology and management strategies for mares affected by persistent post-breeding endometritis. Overall, these mares are considered subfertile but acceptable pregnancy and foaling rates can be achieved with appropriate breeding management.
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Endometrite/veterinária , Doenças dos Cavalos/prevenção & controle , Infecção Puerperal/veterinária , Animais , Cruzamento , Endometrite/prevenção & controle , Feminino , Cavalos , Gravidez , Infecção Puerperal/prevenção & controleRESUMO
The mechanical properties of cells and tissues help determine their architecture, composition and function. Alterations to these properties are associated with many diseases, including cancer. Tensional, compressive, adhesive, elastic and viscous properties of individual cells and multicellular tissues are mostly regulated by reorganization of the actomyosin and microtubule cytoskeletons and extracellular glycocalyx, which in turn drive many pathophysiological processes, including cancer progression. This Review provides an in-depth collection of quantitative data on diverse mechanical properties of living human cancer cells and tissues. Additionally, the implications of mechanical property changes for cancer development are discussed. An increased knowledge of the mechanical properties of the tumour microenvironment, as collected using biomechanical approaches capable of multi-timescale and multiparametric analyses, will provide a better understanding of the complex mechanical determinants of cancer organization and progression. This information can lead to a further understanding of resistance mechanisms to chemotherapies and immunotherapies and the metastatic cascade.
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The objective of this study was to compare the reproductive outcomes (artificial insemination [AI] pregnancy rates, season pregnancy rates, AI pregnancy losses) and calf traits (birth and weaning weights) after vaccination of suckled beef cows against bovine herpesvirus 1 and bovine viral diarrhea virus using commercially-available modified-live virus (MLV) or killed virus (KV) vaccine at the initiation of a fixed-time AI program. Previously-vaccinated cows (n = 2138) on 14 farms throughout Virginia were enrolled in the study during the Fall 2017 and Spring 2018 breeding seasons. Animals received a single vaccination injection at 10 d pre-breeding, corresponding with time of CIDR insertion at initiation of the 7-d CO-Synch + CIDR synchronization protocol. Cows were inseminated at a fixed time (60-66 h after removal of the CIDR insert) and subsequently turned out with bulls approximately 1 wk after insemination for a natural service. Cows treated with the MLV vaccine had greater AI pregnancy rates than cows treated with the KV vaccine during the fall (P = 0.008; 54% vs. 46%, respectively), but not during the spring breeding season (P = 0.62; 48 vs. 49%). Season pregnancy rates were greater (P = 0.01) in the fall (95-96%) than in the spring breeding season (89-90%), but were not affected by vaccine treatment (P = 0.49) or treatment by season (P = 0.30) interactions. Percentage of AI pregnancy losses was not affected by season (P = 0.85), vaccine treatment (P = 0.83), or treatment by season interactions (P = 0.68). The number of cycles it took for cows to become pregnant by natural service differed by season (P = 0.006) but not treatment (P = 0.87) or treatment by season interaction (P = 0.997). Cows treated with the MLV vaccine gave birth earlier in the calving season (8.36 ± 0.6 d) than those treated with the KV vaccine (10.31 ± 0.6 d; P = 0.02). There was a main effect of season on birth weights (P = 0.008), weaning weights (P < 0.001), and ADG at weaning (P < 0.001), but no effects of treatment (P ≥ 0.26) or treatment by season interaction (P ≥ 0.10) on any of these parameters. Overall, this study demonstrated that the administration of an MLV vaccine at 10 d before fixed-time AI did not have any adverse effects on pregnancy or calf outcomes compared with KV vaccine administration.
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Doenças dos Bovinos , Vacinas , Gravidez , Feminino , Bovinos , Animais , Masculino , Resultado da Gravidez , Aborto Animal , Taxa de Gravidez , Inseminação Artificial/veterinária , Vacinação/veterinária , Sincronização do Estro/métodos , Progesterona/farmacologia , Hormônio Liberador de Gonadotropina/farmacologia , Dinoprosta/farmacologiaRESUMO
Background: Trauma-Informed Care (TIC) is an evidence-based approach for improving health outcomes by providing systematic, trauma- sensitive and -responsive care. Because TIC adoption varies by setting and population, Implementation Science (IS) is particularly well-suited to guide roll-out efforts. Process Mapping (PM) is an IS model for creating shared visual depictions of systems as they are to identify rate-limiting steps of intervention adoption, but guidance on how to apply PM to guide TIC adoption is lacking. Authors of this study aimed to develop a novel method for conducting TIC-focused PM. Methods: A real-life TIC implementation study is presented to show how TIC-focused PM was conducted in the case example of a pediatric HIV clinic in a Southern urban area with a high burden of psychological trauma among youth with HIV. A five-phase PM model was applied to evince clinic standards of care, including Preparation, planning and process identification; Data and information gathering; Map generation; Analysis; and Taking it forward. Practices and conditions from four TIC domains were assessed, including Trauma responsive services; Practices of inclusivity, safety, and wellness; Training and sustaining trauma responsiveness; and Cultural responsiveness. Results: The TIC-focused PM method indicated the case clinic provided limited and non-systematic patient trauma screening, assessment, and interventions; limited efforts to promote professional quality of life and elicit and integrate patient experiences and preferences for care; no ongoing efforts to train and prepare workforce for trauma- sensitive or -responsive care; and no clinic-specific efforts to promote diversity, equity, and inclusion for patients and personnel. Conclusion: Principles and constructs of resilience-focused TIC were synthesized with a five-phase PM model to generate a baseline depiction of TIC in a pediatric HIV clinic. Results will inform the implementation of TIC in the clinic. Future champions may follow the TIC-focused PM model to guide context-tailored TIC adoption.
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Background: Psychological trauma is a highly prevalent driver of poor health among people with HIV (PWH) in the Southern United States (U.S.). Trauma-informed care (TIC) has potential to advance national Ending the HIV Epidemic (EHE) goals, but formative research is needed to tailor TIC implementation to complex and interdependent HIV networks. Methods: We applied a community-based participatory research (CBPR) approach to iteratively engage personnel from high volume HIV care institutions in Nashville, Tennessee. Current practices and potential implementation determinants were identified through participatory process mapping (PM) and key informant interviews. The Consolidated Framework for Implementation Research (CFIR) was applied to deductively code interview data. Personnel attending a dissemination summit developed a network-wide implementation plan. Results: Data were collected with personnel from five institutions (e.g., community-based organizations, primary care clinics, public health department), for PM (n=48), interviews (n=35), and the summit (n=17). Results suggest there are limited trauma screenings, assessments, and services across the network. Relevant Characteristics of Individuals included a trauma-sensitive workforce committed to continuous learning and TIC adoption. Relevant Inner Setting Factors were networks and communications, with strong tension for change, high compatibility with TIC, and need for advancing cultural responsiveness. Relevant Outer Setting Factors included patient needs and resources and cosmopolitanism, with need for better leveraged mental health services. Relevant Process domains were champions and leadership, with need to diversify championship among leaders. Relevant Intervention Characteristics included relative advantage and complexity, with need for personnel wellness initiatives and increased engagement with the community as service designers. Four recommendations included development of shared communication systems, personnel wellness campaigns, routine evaluations to inform practices, and culturally responsive care initiatives. Conclusion: Modifiable TIC determinants were identified, and a community-created implementation plan was developed to guide adoption. Future research will focus on city-wide implementation and strengthening pre-implementation research in other settings.
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BACKGROUND: We have used the genomic data in the Integrated Microbial Genomes system of the Department of Energy's Joint Genome Institute to make predictions about rhizobial open reading frames that play a role in nodulation of host plants. The genomic data was screened by searching for ORFs conserved in α-proteobacterial rhizobia, but not conserved in closely-related non-nitrogen-fixing α-proteobacteria. RESULTS: Using this approach, we identified many genes known to be involved in nodulation or nitrogen fixation, as well as several new candidate genes. We knocked out selected new genes and assayed for the presence of nodulation phenotypes and/or nodule-specific expression. One of these genes, SMc00911, is strongly expressed by bacterial cells within host plant nodules, but is expressed minimally by free-living bacterial cells. A strain carrying an insertion mutation in SMc00911 is not defective in the symbiosis with host plants, but in contrast to expectations, this mutant strain is able to out-compete the S. meliloti 1021 wild type strain for nodule occupancy in co-inoculation experiments. The SMc00911 ORF is predicted to encode a "SodM-like" (superoxide dismutase-like) protein containing a rhodanese sulfurtransferase domain at the N-terminus and a chromate-resistance superfamily domain at the C-terminus. Several other ORFs (SMb20360, SMc01562, SMc01266, SMc03964, and the SMc01424-22 operon) identified in the screen are expressed at a moderate level by bacteria within nodules, but not by free-living bacteria. CONCLUSIONS: Based on the analysis of ORFs identified in this study, we conclude that this comparative genomics approach can identify rhizobial genes involved in the nitrogen-fixing symbiosis with host plants, although none of the newly identified genes were found to be essential for this process.
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Proteínas de Bactérias/biossíntese , Perfilação da Expressão Gênica , Nódulos Radiculares de Plantas/microbiologia , Sinorhizobium meliloti/fisiologia , Simbiose , Proteínas de Bactérias/genética , Técnicas de Inativação de Genes , Medicago sativa/microbiologia , Medicago sativa/fisiologia , Mutagênese Insercional , Nodulação , Estrutura Terciária de Proteína , Sinorhizobium meliloti/genética , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genéticaRESUMO
BACKGROUND AND AIMS: Micronutrient supplements such as vitamin D, vitamin C, and zinc have been used in managing viral illnesses. However, the clinical significance of these individual micronutrients in patients with Coronavirus disease 2019 (COVID-19) remains unclear. We conducted this meta-analysis to provide a quantitative assessment of the clinical significance of these individual micronutrients in COVID-19. METHODS: We performed a comprehensive literature search using MEDLINE, Embase, and Cochrane databases through December 5th, 2021. All individual micronutrients reported by ≥ 3 studies and compared with standard-of-care (SOC) were included. The primary outcome was mortality. The secondary outcomes were intubation rate and length of hospital stay (LOS). Pooled risk ratios (RR) and mean difference (MD) with corresponding 95% confidence intervals (CI) were calculated using the random-effects model. RESULTS: We identified 26 studies (10 randomized controlled trials and 16 observational studies) involving 5633 COVID-19 patients that compared three individual micronutrient supplements (vitamin C, vitamin D, and zinc) with SOC. Nine studies evaluated vitamin C in 1488 patients (605 in vitamin C and 883 in SOC). Vitamin C supplementation had no significant effect on mortality (RR 1.00, 95% CI 0.62-1.62, P = 1.00), intubation rate (RR 1.77, 95% CI 0.56-5.56, P = 0.33), or LOS (MD 0.64; 95% CI -1.70, 2.99; P = 0.59). Fourteen studies assessed the impact of vitamin D on mortality among 3497 patients (927 in vitamin D and 2570 in SOC). Vitamin D did not reduce mortality (RR 0.75, 95% CI 0.49-1.17, P = 0.21) but reduced intubation rate (RR 0.55, 95% CI 0.32-0.97, P = 0.04) and LOS (MD -1.26; 95% CI -2.27, -0.25; P = 0.01). Subgroup analysis showed that vitamin D supplementation was not associated with a mortality benefit in patients receiving vitamin D pre or post COVID-19 diagnosis. Five studies, including 738 patients, compared zinc intake with SOC (447 in zinc and 291 in SOC). Zinc supplementation was not associated with a significant reduction of mortality (RR 0.79, 95% CI 0.60-1.03, P = 0.08). CONCLUSIONS: Individual micronutrient supplementations, including vitamin C, vitamin D, and zinc, were not associated with a mortality benefit in COVID-19. Vitamin D may be associated with lower intubation rate and shorter LOS, but vitamin C did not reduce intubation rate or LOS. Further research is needed to validate our findings.
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COVID-19 , Teste para COVID-19 , Humanos , Micronutrientes/uso terapêutico , Vitamina D/uso terapêutico , VitaminasRESUMO
Reproductive tract diseases can be a significant cause of subfertility or infertility in male small ruminants. Affected males can usually be identified early by performing routine serologic screening and yearly breeding soundness examinations. Early diagnosis will either maximize treatment success or expedite culling decisions. Once clinical signs of diseases develop, prognosis for breeding ability declines. Veterinary practitioners should used ancillary diagnostic techniques, such as ultrasound examination and laboratory testing to acquire a diagnosis and determine prognosis of reproductive lesions. Some diseases (eg, brucellosis) should be ruled out immediately to cull affected animals and minimize transmission within the herd.
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Doenças dos Genitais Masculinos/veterinária , Doenças das Cabras/diagnóstico , Doenças das Cabras/terapia , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/terapia , Animais , Doenças dos Genitais Masculinos/diagnóstico , Doenças dos Genitais Masculinos/terapia , Cabras , Masculino , Reprodução , Ruminantes , OvinosRESUMO
Nerve growth factor-ß (NGF) is critical for ovulation in the mammalian ovary and is luteotrophic when administered systemically to camelids and cattle. This study aimed to assess the direct effects of purified bovine NGF on steroidogenesis and angiogenic markers in the bovine pre-ovulatory follicle. Holstein heifers (n = 2) were synchronized with a standard protocol, and heifers with a preovulatory follicle (≥ 12 mm) had the ovary containing the dominant follicle removed via colpotomy. Pre-ovulatory follicles were dissected into 24 pieces containing theca and granulosa cells that were randomly allocated into culture media supplemented with either purified bovine NGF (100 ng/mL) or untreated (control) for 72 h. The supernatant media was harvested for quantification of progesterone, testosterone, and estradiol concentrations, whereas explants were subjected to mRNA analyses to assess expression of steroidogenic and angiogenic markers. Treatment of follicle wall pieces with NGF upregulated gene expression of steroidogenic enzyme HDS17B (P = 0.04) and increased testosterone production (P < 0.01). However, NGF treatment did not alter production of progesterone (P = 0.81) or estradiol (P = 0.14). Consistently, gene expression of steroidogenic enzymes responsible for producing these hormones (STAR, CYP11A1, HSD3B, CYP17A1, CYP19A1) were unaffected by NGF treatment (P ≥ 0.31). Treatment with NGF downregulated gene expression of the angiogenic enzyme FGF2 (P = 0.02) but did not alter PGES (P = 0.63), VEGFA (P = 0.44), and ESR1 (P = 0.77). Collectively, these results demonstrate that NGF from seminal plasma may interact directly on the theca and granulosa cells of the bovine pre-ovulatory follicle to stimulate testosterone production, which may be secondary to theca cell proliferation. Additionally, decreased FGF2 expression in NGF-treated follicle wall cells suggests hastened onset of follicle wall cellular remodeling that occurs during early luteal development.
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The objective of the study was to examine how l-citrulline supplementation to ewes during mid-gestation influences placental activity, placental blood flow, lamb body weight, and carcass characteristics. Two studies were completed. A pharmacokinetic study to compare circulating plasma amino acid concentrations after a single intravenous injection of 155 µmol/kg BW l-citrulline or after an isonitrogenous amount of l-alanine (control; 465 µmol/kg BW). Increases (P < 0.05) in circulating citrulline concentrations were detected for 8 h after l-citrulline injection versus the control. Similarly, increases (P < 0.05) in circulating arginine concentrations were detected for 24 h after l-citrulline treatment. The second study used 12 ewes with twin pregnancies. Daily intravenous injections of either l-citrulline or l-alanine were administered for 39 d from d 42-45 to 81-84 of gestation. Ewes were limit-fed at 85% daily energy requirements during the injection period. A decrease (P < 0.0001) in body weight was observed in both treatment groups during this period. No treatment differences were observed in circulating pregnancy-specific protein B concentrations or placental blood flow during the treatment and post-treatment gestational period. No treatment differences were observed in lamb survival nor in lamb birth, weaning and slaughter weights. Treatment did not influence lamb carcass composition or organ weights. However, there was a tendency (P = 0.10) for an increase in antral follicle numbers in ovaries from ewe lambs derived from ewes treated with l-citrulline. In summary, a daily l-citrulline injection increased both circulating citrulline and arginine concentrations in ewes, but daily l-citrulline injections during mid-gestation did not produce any detectable changes in placental activity and blood flow, neonatal and postnatal lamb development, and lamb carcass composition at slaughter. In conclusion, no benefits in placental function and lamb development were observed after providing l-citrulline during mid-gestation in ewes exposed to a mild energy restriction, but there was an indication that follicle numbers in ewe lambs were positively influenced by l-citrulline treatment during fetal development.
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The objective of this study was to assess differences in reproductive performance of natural service and artificial insemination (AI) sired beef females based on pregnancy outcomes, age at first calving, and calving interval. Data were sourced from 8,938 cows sired by AI bulls and 3,320 cows sired by natural service bulls between 2010 and 2017. All cows were in a commercial Angus herd with 17 management units located throughout Virginia and represented spring and fall calving seasons. All calves were born to dams managed with estrus synchronization. Pregnancy was analyzed with generalized linear mixed models and other reproductive measures with linear mixed models in R. Six models were evaluated with the dependent variables of pregnancy status at the first diagnosis, pregnancy status at the second diagnosis, pregnancy type (AI or natural service) at the first diagnosis, pregnancy type at the second diagnosis, calving interval, and age at first calving. Independent variables differed by model but included sire type of the female (AI or natural service), prebreeding measures of age, weight, and body condition score, postpartum interval, sex of the calf nursing the cow, and management group. No differences were observed between AI- and natural service-sired females based on pregnancy status at first and second pregnancy diagnosis (P > 0.05). Sire type was only found to be significant for age at first calving (P < 0.05) with AI-sired females being 26.6 ± 1.6 d older at their first calving, which was expected because AI-sired females were born early in the calving season making them older at breeding. Surprisingly, age and body condition score were not significant predictors of pregnancy (P > 0.05). Body weight at breeding was not significant for pregnancy (P > 0.05) but was significant for age at first calving (P < 0.05). These data suggested that lighter heifers calved earlier which contradicts our original hypothesis. Overall, commercial Angus females sired by AI or natural service bulls had similar reproductive performance. Factors that were commonly associated with reproductive success were not significant in this commercial Angus herd managed with estrus synchronization. Given the size of these data, the importance of body condition, age, and weight should be reassessed in modern genetics and management practices.
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Nerve growth factor-ß (NGF), initially recognized as a neurotrophin involved in regulating neuronal survival and differentiation, was also later revealed as a ubiquitous seminal plasma protein in mammals. In South American camelids, NGF was initially named ovulation-inducing factor and a dose-dependent luteotropic effect was also reported in llamas. Although NGF was present in the seminal plasma of bulls, the first studies only indicated a potential role on regulation of sperm physiology. The breakthrough discovery of NGF ability to induce ovulation in camelids led to a series of studies investigating the potential functions of NGF within the female reproductive system. In the bovine, a potential luteotropic effect of NGF was perceived as potential tool to overcome the current issues with early embryonic losses attributed at least in part to luteal insufficiency and failed maternal recognition of pregnancy. The aims of this review are to discuss recent advancements in the understanding of the biological roles of NGF in the bovine species. The insights of recent studies with NGF administered in cattle include enhancement of steroidogenesis, luteal formation, and function through increased release of LH, and downstream effect of increased expression of interferon-stimulated genes. In addition, a positive association with sire conception rates; the determination that is produced in the ampulla and vesicular glands of bulls and that is secreted into the sperm-rich fraction of the ejaculate; and the absence of improved post-thaw sperm motility, viability, acrosome integrity, or chromatin stability in ejaculated or epididymal derived sperm supplemented with purified NGF is also discussed.
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Hormônio Luteinizante/metabolismo , Fator de Crescimento Neural/metabolismo , Animais , Bovinos , Corpo Lúteo/fisiologia , Feminino , Sistema Hipotálamo-Hipofisário/fisiologia , MasculinoRESUMO
The objective of this study was to determine the effects of bovine nerve growth factor-ß (NGF) on pre-ovulatory follicle vascular area, LH release, ovulation, and luteal function when administered systemically to heifers. Post-pubertal Holstein heifers (n = 12) received an intravaginal progesterone-releasing device (CIDR) and GnRH agonist (100 µg IM). The CIDR was removed 5 d later, and heifers were given dinoprost (25 mg IM) at CIDR removal and 24 h later, followed by a second dose of GnRH agonist 48 h later. Heifers were randomly assigned to treatments using a cross-over design. For example, heifers assigned to NGF (250 µg reconstituted in 12 mL PBS IM) in replicate 1 were assigned to control (12 mL PBS IM) in replicate 2. Transrectal ultrasonography was performed before treatment and repeated every 4 h up to 32 h to determine the pre-ovulatory follicle diameter, vascular area, and ovulation. Serum samples were obtained to assess LH concentrations during the periovulatory period and every 2 d post-ovulation for measuring progesterone concentrations. A subset of heifers had luteal biopsies performed on days 9 (n = 6 per treatment) and 14 (n = 6 per treatment) post-ovulation to count luteal cell numbers and measure relative mRNA abundance for steroidogenic and angiogenic enzymes and LH receptor. Treatment with NGF increased pre-ovulatory follicle diameter (P = 0.02) and serum LH concentrations (P = 0.03) but did not affect time to ovulation (P = 0.42). Heifers treated with NGF had increased serum progesterone concentrations in the subsequent luteal phase (P = 0.03), but no change in vascular area of the follicle (P = 0.16) or CL (P = 0.20). Heifers treated with NGF had a greater number of small luteal cells (P < 0.01) and a tendency for increased LH receptor (LHR) mRNA abundance in the CL (P = 0.10). There was also increased steroidogenic acute regulatory protein (STAR; P = 0.05) and a tendency for increased cytochrome P450 family 11 (CYP11A1; P = 0.10) mRNA abundance in the CL of NGF-treated heifers. There was decreased prostaglandin E2 synthase (PGES; P = 0.03) and its receptor (PGER; P = 0.05) mRNA abundance and a tendency for decreased cytochrome P450 family 17 subfamily A member 1 (CYP17A1; P = 0.08) and hydroxysteroid 17-beta dehydrogenase (HSD17B; P = 0.06) mRNA abundance in the CL of NGF-treated heifers. Administration of NGF improved CL function in heifers potentially as a result of increased LH release.
Assuntos
Bovinos , Corpo Lúteo/efeitos dos fármacos , Hormônio Luteinizante/metabolismo , Fator de Crescimento Neural/farmacologia , Folículo Ovariano/efeitos dos fármacos , Animais , FemininoRESUMO
Nerve growth factor-ß (NGF) is a seminal plasma protein associated with improved sperm membrane integrity and motility in mammalian species. The objective of this study was to compare post-thaw semen quality from both ejaculated and pididymal-collected bull sperm incubated with purified NGF prior to cryopreservation. Semen was obtained from Angusâ¯×â¯Simmental crossbred bulls (nâ¯=â¯10) collected by electroejaculation, followed by castration and epididymal sperm collections 3 days later. Semen samples were incubated with extender having 0â¯ng/mL (CONT), 0.5â¯ng/mL (LOW), 5â¯ng/mL (MED), or 50â¯ng/mL (HIGH) of purified NGF prior to cryopreservation. Sperm motility was assessed in each sample prior to treatment and cryopreservation and at post-thaw. Flow cytometry was used for post-thaw assessment of sperm viability (SYBR-14/PI), acrosome integrity (FITC-PNA/PI), and chromatin stability (acridine orange). Values for post-thaw sperm motility and velocity variables were decreased, while linearity was increased in samples of the HIGH compared with CONT group (P < 0.01), but there were no differences in epididymal samples (P> 0.05). Samples from the HIGH group also had a lesser amplitude of lateral head displacement at 2.5 and 3â¯h post-thaw (P < 0.01). Post-thaw sperm viability, acrosome integrity, and DNA fragmentation index were not affected by NGF treatment in either ejaculated or epididymal sperm (P> 0.05). In conclusion, supplementation of freezing extender with NGF had minimal effects on post-thaw sperm quality in bulls. Results indicate NGF may have a function in preventing premature sperm hyperactivation in ejaculated, but not epididymal-collected spermatozoa. Fertility studies, both in vitro and in vivo, are warranted to ascertain the relevancy of these findings.
Assuntos
Bovinos , Criopreservação , Crioprotetores/farmacologia , Fator de Crescimento Neural/farmacologia , Preservação do Sêmen , Sêmen/efeitos dos fármacos , Animais , Criopreservação/métodos , Criopreservação/veterinária , Crioprotetores/administração & dosagem , Combinação de Medicamentos , Ejaculação/fisiologia , Estimulação Elétrica , Congelamento/efeitos adversos , Masculino , Fator de Crescimento Neural/administração & dosagem , Sêmen/fisiologia , Análise do Sêmen/veterinária , Preservação do Sêmen/métodos , Preservação do Sêmen/veterinária , Recuperação EspermáticaRESUMO
Nerve Growth Factor-ß (NGF) is a seminal plasma protein that regulates sperm physiology in bulls, yet its production and association with fertility remain unclear. The objective of this study was to describe NGF distribution in bull accessory sex glands, quantify its seminal plasma concentrations, and determine its association with sire conception rates. Accessory sex glands were collected post-mortem from mature bulls (n = 3). Quantitative PCR and immunohistochemistry were performed in tissue samples. Pre-ejaculate and sperm-rich fraction of seminal plasma from Angus (n = 42) and sperm-rich fraction from Holstein (n = 10) bulls were collected by electroejaculation. Holstein (n = 76) and Jersey (n = 14) bulls were collected by artificial vagina, and those with available sire conception rate scores were allocated to: (1) negative/0 (n = 15); or (2) positive (n = 45). Seminal plasma NGF concentrations were measured using ELISA. Relative abundance of NGF mRNA was greatest in the vesicular, intermediate in ampulla, and lowest in prostate and bulbourethral glands (P ≤ 0.03). The most intense NGF staining was detected in the ampulla and vesicular glands (P < 0.05). Concentrations of NGF were greater in the sperm-rich fraction than in the pre-ejaculate and in samples collected by artificial vagina (P < 0.01). Seminal plasma NGF concentrations were greater in bulls with positive sire conception rate than those with negative/0 (P = 0.05). This study determined that NGF is produced in the ampulla and vesicular glands of bulls and is secreted into the sperm-rich fraction of the ejaculate. The positive association of NGF with bull fertility warrants further investigation.
Assuntos
Bovinos/fisiologia , Fertilidade/fisiologia , Espermatozoides/fisiologia , Animais , Feminino , Fertilização , Expressão Gênica , Masculino , Gravidez , Taxa de Gravidez , SêmenRESUMO
White-tailed deer farming is a growing industry in the United States, with breeding operations contributing significantly to the industry's economic impact. Artificial insemination with frozen semen allows for selection and dissemination of valuable genetics, yet surprisingly little is known regarding the best time throughout rut to perform semen cryopreservation. The objective of this study was to compare semen quality following cryopreservation of white-tailed deer bucks collected early in the breeding season (September, nâ¯=â¯6), at peak rut (December, nâ¯=â¯8), and late season (March, nâ¯=â¯7). We hypothesized that post-thaw semen quality would be enhanced at peak rut. Mature bucks were anesthetized with tiletamine-zolazepam and xylazine administered intramuscularly via projector. Semen was collected by electroejaculation and cryopreserved using Optixcell extender. Overall and progressive sperm motilities were assessed for each sample before and after cryopreservation using a computer-aided sperm analyzer. Flow cytometry was used for post-thaw assessment of sperm viability (SYBR-14/PI), acrosome integrity (FITC-PNA/PI), and DNA stability (acridine orange). Analysis of variance was applied to normalized data using a general linear mixed model with buck ID as a random variable, and a Tukey HSD test was performed as needed for post-hoc analysis. Pre-freeze overall and progressive sperm motilities were lowest in March, intermediate in September, and highest in December (pâ¯≤â¯0.04). Post-thaw overall and progressive motilities were lowest in September (pâ¯≤â¯0.02), but did not differ between December and March (pâ¯≥â¯0.12). The DNA Fragmentation Index was lowest in December, intermediate in September, and highest in March (pâ¯≤â¯0.05). The percentage of spermatozoa with intact plasma membrane was higher in December than September (pâ¯<â¯0.01), but the percentage of intact acrosomes per sperm with intact plasma membrane was highest in September (pâ¯=â¯0.03). This study confirms that post-thaw semen quality appears to be superior during peak rut (December) in bucks. Though semen collected early or late in rut may present acceptable motility, DNA stability is impaired, which could adversely affect fertility rates. This data suggests that semen cryopreservation during transitional periods should be avoided, though field studies evaluating the translation of these results into satisfactory pregnancy rates are warranted.