RESUMO
In brief: Paternal high-gain diet reduces blastocyst development following in vitro fertilization and embryo culture but does not affect gene expression or cellular allocation of resultant blastocysts. Abstract: Bulls used in cattle production are often overfed to induce rapid growth, early puberty, and increase sale price. While the negative consequences of undernutrition on bull sperm quality are known, it is unclear how a high-gain diet influences embryo development. We hypothesized that semen collected from bulls fed a high-gain diet would have a reduced capacity to produce blastocysts following in vitro fertilization. Eight mature bulls were stratified by body weight and fed the same diet for 67 days at either a maintenance level (0.5% body weight per day; n = 4) or a high-gain rate (1.25% body weight per day; n = 4). Semen was collected by electroejaculation at the end of the feeding regimen and subjected to sperm analysis, frozen, and used for in vitro fertilization. The high-gain diet increased body weight, average daily gain, and subcutaneous fat thickness compared to the maintenance diet. Sperm of high-gain bulls tended to have increased early necrosis and had increased post-thaw acrosome damage compared with maintenance bulls, but diet did not affect sperm motility or morphology. Semen of high-gain bulls reduced the percentage of cleaved oocytes that developed to blastocyst stage embryos. Paternal diet had no effect on the number of total or CDX2-positive cells of blastocysts, or blastocysts gene expression for markers associated with developmental capacity. Feeding bulls a high-gain diet did not affect sperm morphology or motility, but increased adiposity and reduced the ability of sperm to generate blastocyst-stage embryos.
Assuntos
Sêmen , Motilidade dos Espermatozoides , Masculino , Bovinos , Animais , Desenvolvimento Embrionário , Fertilização in vitro/veterinária , Espermatozoides/metabolismo , Blastocisto , Dieta/veterinária , Peso CorporalRESUMO
Reactions involving reductive aggregation of MnO4- in methanol in the presence of CeIV and an excess of carboxylic acid have led to the synthesis of structurally related Ce/Mn clusters, [Ce3Mn5O8(OMe)(O2CBut)13(MeOH)] (1) and [Ce2Mn3O5(O2CPh)9(MeOH)3] (2), containing at least one {Mn2Ce2O4} cubane unit. The cores of both clusters contain Mnx units separated by three (1) or two (2) CeIV ions. Fits of variable-temperature, solid-state dc and ac magnetic susceptibility data reveal dominant ferromagnetic interactions within 1 and 2, resulting in the maximum S = 17/2 and S = 5 ground state spins, respectively, and thus suggesting significant ferromagnetic (F) interactions between the Mnx units that are ≥6 Å apart and separated by four intervening bonds through diamagnetic CeIV. Fits of magnetic susceptibility data also revealed unusual long-range F interactions, and this finding was further supported by high-field EPR measurements and simulations. Density functional theory calculations and a Wannier function analysis confirm long-range interactions and indicate a Mn-Ce-Mn superexchange pathway via Mn-d/Ce-f orbital overlap/hybridization.
RESUMO
The demand for a year-round supply of fresh, locally grown, forage-finished beef products has created a need for forage-finishing strategies during the summer months in the southeast. A 3-yr study was conducted to evaluate four warm-season annual forages in a southeastern forage-finishing beef production system. Treatments were four forage species and included brown-midrib sorghum × sudangrass (Sorghum bicolor var. bicolor*bicolor var. sudanense; BMR), sorghum × sudangrass (SS), pearl millet [Pennisetum glaucum (L.) R. Br.; PM], or pearl millet planted with crabgrass [Digitaria sanguinalis (L.) Scop.; PMCG]. Treatments were distributed in a randomized complete block design with four replicates. Pastures (0.81 ha, experimental unit) were assigned to one of four forage treatments, subdivided, and rotationally stocked with a variable stocking density. British-cross beef steers (n = 32; 3-yr average: 429 ± 22 kg) grazed for 70, 63, and 56 d in 2014, 2015, and 2016, respectively. Put-and-take animals were used to maintain a forage allowance of 116 kg forage dry matter /100 kg body weight. Forage mass was measured by clipping a 4.3-m2 area in triplicate on d 0 and on 14-d intervals. Hand grab samples for forage nutritive value determination and quadrat clippings for species compositions were measured on d 0 and on 34-d intervals until termination of the trial. Forage mass was lowest (P < 0.01) for PMCG at the initiation of the grazing trial, whereas BMR was greater (P < 0.01) than SS at wk 6. Total digestible nutrients in 2014 were greater for SS compared to BMR and PM at the middle harvest (P < 0.01) and BMR, PM, and PMCG at the final harvest (P < 0.01). At the middle and final harvests in both 2015 and 2016, PM and PMCG contained greater (P < 0.01) concentrations of crude protein than SS. These results suggest that BMR, SS, PM, and PMCG may all be used in southeastern forage-finishing beef production systems, as long as the producer strategically accounts for the slight growth and nutritive value differences throughout the season.
RESUMO
Patients with symptomatic severe aortic stenosis (AS) benefit from aortic valve replacement surgery, but the management of patients with asymptomatic severe AS is more controversial. While cholesterol and angiotensin have been linked to AS progression, we should await the results of ongoing randomized trials before medical therapy to lower cholesterol or inhibit angiotensin can be recommended to limit disease progression. Clinical factors, echocardiographic parameters, valve morphology, exercise stress testing results, and cardiac biomarkers may be useful in identifying patients who will have early development of symptoms during follow-up and require closer monitoring. The risks associated with aortic valve replacement outweigh the benefits in the majority of patients with asymptomatic severe AS.
RESUMO
The primary emphasis of tissue engineering is the design and fabrication of constructs for the replacement of nonfunctional tissue. Because tissue represents a highly organized interplay of cells and extracellular matrix, the fabrication of replacement tissue should mimic this spatial organization. This report details studies evaluating the use of a three-dimensional, direct-write cell deposition system to construct spatially organized viable structures. A direct-write bioassembly system was designed and fabricated to permit layer-by-layer placement of cells and extracellular matrix on a variety of material substrates. Human fibroblasts suspended in polyoxyethylene/polyoxypropylene were coextruded through a positive displacement pen delivery onto a polystyrene slide. After deposition, approximately 60% of the fibroblasts remained viable. Bovine aortic endothelial cells (BAECs) suspended in soluble collagen type I were coextruded via microdispense pen delivery onto the hydrophilic side of flat sheets of polyethylene terephthalate. After deposition with a 25-gauge tip, approximately 86% of the BAECs were viable. When maintained in culture for up to 35 days, the constructs remained viable and maintained their original spatial organization. These results indicate the potential for utilizing a direct-write, three-dimensional bioassembly tool to create viable, patterned tissue-engineered constructs.
Assuntos
Técnicas de Cultura de Células/métodos , Células Endoteliais/citologia , Células Endoteliais/fisiologia , Fibroblastos/citologia , Fibroblastos/fisiologia , Micromanipulação/instrumentação , Engenharia Tecidual/métodos , Animais , Bovinos , Células Cultivadas , Colágeno Tipo I/química , Periféricos de Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Micromanipulação/métodos , Impressão , Robótica/instrumentaçãoRESUMO
OBJECTIVE: To demonstrate the expression of soluble guanylyl cyclase (sGC) alpha and beta subunits in rat granulosa cells and determine the effects sGC activation on levels of cyclic GMP (cGMP), E2, and cAMP. DESIGN: Basic research study. SETTING: University research laboratory. ANIMAL(S): Estrogen-treated immature Sprague-Dawley female rats from which primary cell culture of granulosa cells was obtained. INTERVENTION(S): Functionally immature rat granulosa cells were incubated for 48 hours with media alone, FSH, or FSH plus YC-1, a specific activator of sGC. MAIN OUTCOME MEASURE(S): Expression of sGC alpha and beta subunits was determined by immunoblot analysis. Media concentrations of E2, cAMP, and cGMP were measured by radioimmunoassays. RESULT(S): Immunoblot analysis of granulosa cells revealed the expression of sGC alpha and beta subunits. While cGMP accumulation was low in cells incubated with media alone or with FSH, cotreatment with FSH plus YC-1 increased cGMP levels approximately five-fold. Incubation of cells with FSH stimulated E2 production in a dose-dependent manner. However, cotreatment of cells with FSH plus YC-1 significantly decreased E2 concentrations at all doses of FSH tested. Similarly, while FSH increased cAMP accumulation from granulosa cells, cotreatment with YC-1 markedly inhibited FSH-stimulated cAMP levels. CONCLUSION(S): These findings demonstrate the expression of sGC subunits in rat granulosa cells and indicate that activation of sGC increases cGMP levels, which are associated with inhibition of FSH-stimulated E2 production and cAMP accumulation.
Assuntos
AMP Cíclico/antagonistas & inibidores , Estradiol/biossíntese , Células da Granulosa/metabolismo , Guanilato Ciclase/metabolismo , Animais , Células Cultivadas , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Sinergismo Farmacológico , Ativação Enzimática/fisiologia , Ativadores de Enzimas/farmacologia , Feminino , Hormônio Foliculoestimulante/farmacologia , Células da Granulosa/enzimologia , Guanilato Ciclase/química , Hormônios/farmacologia , Immunoblotting , Indazóis/farmacologia , Isoenzimas/química , Isoenzimas/metabolismo , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , SolubilidadeRESUMO
Soluble guanylyl cyclase (sGC) is activated by nitric oxide (NO) and carbon monoxide, resulting in cGMP production. Recent studies indicate that NO and cGMP influence ovarian functions. However, little information is available regarding the ovarian expression of sGC. The present study examined sGC alpha(1) and beta(1) subunit protein levels in the ovary during postnatal development, gonadotropin-induced follicle growth, ovulation, and luteinization as well as in cultured rat granulosa cells. In postnatal rats, sGC alpha(1) subunit immunoreactivity was high in granulosa cells of primordial and primary follicles on Day 5 but low in granulosa cells of larger follicles on Days 10 and 19. Theca cells of developing follicles, but not stromal cells, also demonstrated moderate sGC alpha(1) immunoreactivity. In gonadotropin- treated immature rats, intense sGC alpha(1) subunit staining was similarly observed in granulosa cells of primordial and primary follicles, but such staining was low in granulosa cells of small antral follicles and undetectable in granulosa cells of large antral and preovulatory follicles. Following ovulation, corpora lutea expressed moderate sGC alpha(1) immunoreactivity. Similar ovarian localization and expression patterns were seen for sGC beta(1), indicating regulated coexpression of sGC subunits. Immunoblot analysis revealed no change in total ovarian sGC alpha(1) and beta(1) subunit protein levels during gonadotropin treatment. Similarly, no effect of FSH on sGC subunit protein levels was apparent in cultured granulosa cells. These findings indicate regulated, cell- specific patterns of sGC expression in the ovary and are consistent with roles for cGMP in modulating ovarian functions.
Assuntos
Guanilato Ciclase/metabolismo , Ovário/enzimologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Feminino , Gonadotropinas/farmacologia , Células da Granulosa/enzimologia , Guanilato Ciclase/química , Imuno-Histoquímica , Luteinização , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/enzimologia , Ovário/citologia , Ovário/efeitos dos fármacos , Ovulação , Subunidades Proteicas , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , SolubilidadeRESUMO
BACKGROUND: Complementary and alternative medical (CAM) therapies are becoming increasingly popular, yet little information is available about the prevalence and patterns of CAM therapy use by patients with cardiovascular disease (CVD). METHODS: Interviewers administered telephone questionnaires to 107 patients randomly selected from a stratified cohort of 2487 eligible patients participating in a registry of patients with CVD. RESULTS: The current use of CAM therapies was reported by 64% of the patients surveyed. Nutritional supplements (40%) and megadose vitamins (35%) were the most frequently used preparations. Most CAM therapy users (65%) cited their underlying cardiac condition as the reason for taking such therapy. The most common sources of information about CAM were a friend or relative (43%) or the respondent's usual physician. However, although 80% of respondents claimed that they had discussed their use of CAM therapies with their physician, 58% of respondents taking a potentially toxic cardiovascular medication (digoxin, warfarin, sotalol, or amiodarone) were simultaneously taking an oral supplement. CONCLUSION: The use of CAM therapies was high in the cohort of patients surveyed. Physicians caring for patients with CVD need to inquire about CAM therapy use. Further scientific study should be performed to evaluate the potential benefits and risks of CAM therapies in this patient population.