Search results for "Cattle"
showing 10 items of 608 documents
Multiple actions of glaucine on cyclic nucleotide phosphodiesterases, α1-adrenoceptor and benzothiazepine binding site at the calcium channel
1992
1. In the present study, the properties of glaucine (an aporphine structurally related to papaverine) were compared with those of papaverine, diltiazem, nifedipine and prazosin. The work includes functional studies on rat isolated aorta contracted with noradrenaline, caffeine or KCl, and a determination of the affinity of glaucine at calcium channel binding sites of alpha-adrenoceptors, by use of [3H]-(+)-cis-diltiazem, [3H]-nitrendipine and [3H]-prazosin binding to cerebral cortical membranes. The effects of glaucine on the different molecular forms of cyclic nucleotide phosphodiesterases (PDE) isolated from bovine aorta were also determined. 2. Contraction evoked by noradrenaline (1 micro…
Investigations of the dual contractile/relaxant properties showed by antioquine in rat aorta.
1993
1. In the present study we assessed the activity of antioquine, a bisbenzyltetrahydroisoquinoline alkaloid isolated from Pseudoxandra sclerocarpa, by examining its effects on the contractile activity of rat isolated aorta, specific binding of [3H]-(+)-cis-diltiazem, [3H]-nitrendipine and [3H]-prazosin to cerebral cortical membranes and the different molecular forms of cyclic nucleotide phosphodiesterases (PDE) isolated from bovine aorta. 2. Contractions in rat aorta induced by high concentrations of KCl (80 mM) and noradrenaline (1 microM) were inhibited by antioquine in a concentration-dependent manner (0.1 microM- 300 microM). The alkaloid appeared more potent against KCl-induced contract…
Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex
2016
This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph) with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively). Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P < 0.001) although with impo…
The 3,4-oxide is responsible for the DNA binding of benzo[ghi]perylene, a polycyclic aromatic hydrocarbon without a “classic” bay-region
2008
Abstract The polycyclic aromatic hydrocarbon (PAH) benzo[ghi]perylene (BghiP) lacks a “classic” bay-region and is therefore unable to form vicinal dihydrodiol epoxides thought to be responsible for the genotoxicity of carcinogenic PAHs like benzo[a]pyrene. The bacterial mutagenicity of BghiP increases considerably after inhibition of the microsomal epoxide hydrolase (mEH) indicating arene oxides as genotoxic metabolites. Two K-region epoxides of BghiP, 3,4-epoxy-3,4-dihydro-BghiP (3,4-oxide) and 3,4,11,12-bisepoxy-3,4,11,12-tetrahydro-BghiP (3,4,11,12-bisoxide) identified in microsomal incubations of BghiP are weak bacterial mutagens in strain TA98 of Salmonella typhimurium with 5.5 and 1.5…
Piwi Proteins and piRNAs in Mammalian Oocytes and Early Embryos
2015
SummaryGerm cells of most animals critically depend on piRNAs and Piwi proteins. Surprisingly, piRNAs in mouse oocytes are relatively rare and dispensable. We present compelling evidence for strong Piwi and piRNA expression in oocytes of other mammals. Human fetal oocytes express PIWIL2 and transposon-enriched piRNAs. Oocytes in adult human ovary express PIWIL1 and PIWIL2, whereas those in bovine ovary only express PIWIL1. In human, macaque, and bovine ovaries, we find piRNAs that resemble testis-borne pachytene piRNAs. Isolated bovine follicular oocytes were shown to contain abundant, relatively short piRNAs that preferentially target transposable elements. Using label-free quantitative pr…
Combined effect of type and capture area of counting chamber and diluent on Holstein bull sperm kinematics
2018
The evaluation of sperm motion is crucial for processing of seminal doses for artificial insemination. Here, the combined effect of the type and capture area of three counting chambers, together with the type of diluent employed, on sperm motility was analysed. Ejaculates from thirteen Holstein bulls were used for sperm kinematic analysis with the ISAS® v1 CASA-Mot system, using two capillary-loaded counting chambers (Leja® and Cell-Vu® ) and one drop displacement chamber (Makler® ). Nine fixed positions were analysed per chamber type, considering central and lateral and three longitudinal fields. Independent of the diluent used, differences were found between the three chambers. Independen…
Comparative infectivity of Fasciola hepatica metacercariae from isolates of the main and secondary reservoir animal host species in the Bolivian Alti…
2000
Fascioliasis due to Fasciola hepatica (Linnaeus, 1758) is an endemic disease on the Northern Bolivian Altiplano, where human prevalences and intensities are the highest known, sheep and cattle are the main reservoir hosts, and pigs and donkeys the secondary ones. Investigations were carried out to study the viability of metacercariae experimentally obtained from eggs shed by naturally infected Altiplanic sheep, cattle, pigs and donkeys. A total of 157 Wistar rats were infected with doses of 5, 10, 20 and 150 metacercariae. Metacercariae aged for different number of weeks were used to analyse the influence of age on their viability. The number of worms successfully developed in each rat was …
Spatial analysis of bovine spongiform encephalopathy in Galicia, Spain (2000–2005)
2007
Abstract In Spain, the first bovine spongiform encephalopathy (BSE) case was detected in 2000 in a cow born in the Galicia region (Northwestern Spain). From then and until October 2005, 590 cases were detected, 223 of them in Galicia. In 1994, meat and bone meal (MBM) was banned on ruminant feed and, in 1996, an EU decision mandating an overall change in MBM processing was implemented. This decision was gradually applied in the territory and not enforced before July 1998. The objective of this study was to explore clustering of BSE cases and estimate the standard incidence ratio (SIR) of BSE in Galicia. Our study was based on the BSE cases detected during the surveillance period 2000–2005 i…
Morphometry and subpopulation structure of Holstein bull spermatozoa: variations in ejaculates and cryopreservation straws
2016
Artículo científico Sperm quality is evaluated for the calculation of sperm dosage in artificial reproductive programs. The most common parameter used is motility, but morphology has a higher potential as a predictor of genetic quality. Morphometry calculations from CASA‑Morph technology improve morphological evaluation and allow mathematical approaches to the problem. Semen from 28 Holstein bulls was collected by artificial vagina, and several ejaculates were studied. After general evaluation, samples were diluted, packaged in 0.25 ml straws, and stored in liquid nitrogen. Two straws per sample were thawed, and slides were processed and stained with Diff‑Quik. Samples were analyzed by a CA…
A comparative study of the sperm nuclear morphometry in cattle, goat, sheep, and pigs using a new computer-assisted method (CASMA-F)
2012
This study was designed to compare the sperm nuclear morphometry of four species of domestic artiodactyls (cattle, sheep, goats, and pigs), using the newly developed automatic computer-assisted sperm morphometry analysis-F. The study was divided into two experiments. In the first experiment, samples from 20 males from each species were collected, diluted, and divided into four sample aliquots. The first was labeled directly with Hoechst 33342, and the others were processed as smears. Between smears, one group was directly labeled with Hoechst after air drying, and the other was fixed either with glutaraldehyde (GLUT), or with methanol, and afterward labeled with Hoechst. Digital images of t…