RESUMO
VanA-type vancomycin-resistant enterococci isolates from bloodstream infections in Cuba were genetically characterized. Enterococcus faecalis isolates were assigned to sequence type (ST) 28, closely related to Eastern Europe, while Enterococcus faecium belonged to ST262, ST656 and ST1349, and showed different genetic profiles.
RESUMO
Lactating dairy cows have unique reproductive responses compared to when they were heifers that result in distinctly different reproductive measurements and pregnancy outcomes that can be partially overcome with pharmacological strategies. These parameters include circulating progesterone and estradiol concentrations, ovulatory follicle and corpus luteum diameter, incidence of anovulation and double ovulations, time in estrus, pregnancies per artificial insemination and pregnancy losses. Circulating concentrations of progesterone during diestrus are approximately half that in cows compared with heifers. This marked difference in progesterone is likely the explanation for an increased size in diameter of the ovulatory follicle and incidence of double ovulations in cows compared with heifers. Differences in diameter of the ovulatory follicle may explain why cows have greater corpora lutea diameters compared to heifers. The increase in double ovulations appears to be a key driver in the increase in twinning and pregnancy loss as dairy heifers transition to primi- and multiparous cows. Reduced estradiol concentrations in cows at time of estrus helps to explain the decreased duration of estrus in cows compared with heifers...(AU)
Assuntos
Animais , Feminino , Bovinos , Bovinos/metabolismo , Bovinos/fisiologia , Folículo Ovariano , Progesterona , Corpo LúteoRESUMO
Lactating dairy cows have unique reproductive responses compared to when they were heifers that result in distinctly different reproductive measurements and pregnancy outcomes that can be partially overcome with pharmacological strategies. These parameters include circulating progesterone and estradiol concentrations, ovulatory follicle and corpus luteum diameter, incidence of anovulation and double ovulations, time in estrus, pregnancies per artificial insemination and pregnancy losses. Circulating concentrations of progesterone during diestrus are approximately half that in cows compared with heifers. This marked difference in progesterone is likely the explanation for an increased size in diameter of the ovulatory follicle and incidence of double ovulations in cows compared with heifers. Differences in diameter of the ovulatory follicle may explain why cows have greater corpora lutea diameters compared to heifers. The increase in double ovulations appears to be a key driver in the increase in twinning and pregnancy loss as dairy heifers transition to primi- and multiparous cows. Reduced estradiol concentrations in cows at time of estrus helps to explain the decreased duration of estrus in cows compared with heifers...
Assuntos
Feminino , Animais , Bovinos , Bovinos/fisiologia , Bovinos/metabolismo , Folículo Ovariano , Corpo Lúteo , ProgesteronaRESUMO
The objective was to determine the effect of sequence of insemination after simultaneous thawing of multiple 0.5 mL semen straws on conception rate in suckled multiparous Nelore cows. The effect of this thawing procedure on in vitro sperm characteristics was also evaluated. All cows (N = 944) received the same timed AI protocol. Ten straws (0.5 mL) of frozen semen from the same batch were simultaneously thawed at 36 °C, for a minimum of 30 sec. One straw per cow was used for timed AI. Frozen semen from three Angus bulls was used. Timed AI records included sequence of insemination (first to tenth) and time of semen removal from thawing bath. For laboratory analyses, the same semen batches used in the field experiment were evaluated. Ten frozen straws from the same batch were thawed simultaneously in a thawing unit identical to that used in the field experiment. The following sperm characteristics were analyzed: sperm motility parameters, sperm thermal resistance, plasma and acrosomal membrane integrity, lipid peroxidation, chromatin structure, and sperm morphometry. Based on logistic regression, there were no significant effects of breeding group, body condition score, AI technician, and sire on conception rate, but there was an interaction between sire and straw group (P = 0.002). Semen from only one bull had decreased (P < 0.05) field fertility for the group of straws associated with the longest interval from thawing to AI. However, the results of the laboratory experiment were unable to explain the findings of the field experiment. Sperm width:length ratio of morphometric analysis was the single sperm characteristic with a significant interaction between sire and straw group (P = 0.02). It was concluded that sequence of insemination after simultaneous thawing of 10 semen straws can differently affect conception rates at timed AI, depending on the sire used. Nevertheless, the effects of this thawing environment on in vitro sperm characteristics, remain to be further investigated.
Assuntos
Bovinos/fisiologia , Criopreservação/veterinária , Fertilização/fisiologia , Temperatura Alta , Inseminação Artificial/veterinária , Preservação do Sêmen/veterinária , Acrossomo/ultraestrutura , Animais , Cruzamento/métodos , Cromatina/ultraestrutura , Criopreservação/métodos , Feminino , Inseminação Artificial/métodos , Masculino , Paridade , Gravidez , Preservação do Sêmen/métodos , Motilidade dos Espermatozoides , Espermatozoides/anormalidades , Espermatozoides/fisiologia , Espermatozoides/ultraestrutura , Fatores de TempoRESUMO
BACKGROUND AND PURPOSE: ATP is released in response to cellular damage, and P2X7 receptors have an essential role in the onset and maintenance of pathological changes. Haemorrhagic cystitis (HC) is a well-known adverse effect of therapy with cyclophosphamide used for the treatment of many solid tumours and autoimmune conditions. Here we have evaluated the role of P2X7 receptors in a model of HC induced by cyclophosphamide. EXPERIMENTAL APPROACH: Effects of pharmacological antagonism or genetic deletion of P2X7 receptor on cyclophosphamide-induced HC in mice was assessed by nociceptive and inflammatory measures. In addition, the presence of immunoreactive P2X7 receptors was assessed by immunohistochemistry. KEY RESULTS: Pretreatment with the selective P2X7 receptor antagonist A-438079 or genetic ablation of P2X7 receptors reduced nociceptive behaviour scores in the HC model. The same strategies decreased both oedema and haemorrhage indices, on macroscopic or histological evaluation. Treatment with A-438079 decreased the staining for c-Fos in the lumbar spinal cord and brain cortical areas. Treatment with A-438079 also prevented the increase of urinary bladder myeloperoxidase activity and macrophage migration induced by cyclophosphamide and reduced the tissue levels of IL-1ß and TNF-α. Finally, P2X7 receptors were markedly up-regulated in the bladders of mice with cyclophosphamide-induced HC. CONCLUSIONS AND IMPLICATIONS: P2X7 receptors were significantly involved in a model of HC induced by cyclophosphamide. Pharmacological inhibition of these receptors might represent a new therapeutic option for this pathological condition.