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121.
The contents of dopamine (DA), noradrenaline (NA), serotonin (5HT), and some related metabolites were studied in different brain regions of rainbow trout at two different stages of sexual maturation (at the beginning of vitellogenesis), after naphthalene (NAP) administration. The effects of NAP varied according to duration of exposure, brain region and vitellogenesis stage of the trout, and were more significant during previtellogenesis. The changes observed in DA metabolism were generally stimulatory after exposure for 3 h, and either stimulatory or inhibitory (depending on the brain regions) after exposure for 3 days to NAP. NA levels were altered by NAP in various brain regions, but only during previtellogenesis. With respect to 5HT, treatment with NAP reduced levels of the amine and/or its main metabolite in most of the brain regions studied, particularly 3 h after treatment. The results suggest that NAP might interfere with the processes regulating brain monoamine metabolism, either locally or indirectly by altering steroid feedback to brain centres, and thus disrupt endocrine control of reproductive development through the brain–pituitary axis.  相似文献   
122.
In this work, we investigated the spasmolytic effect of caulerpine, a bisindole alkaloid isolated from marine algae of the Caulerpa genus, on guinea pig ileum. Our findings indicated that caulerpine inhibited phasic contractions induced by carbachol (IC50 = 7.0 ± 1.9 × 10−5 M), histamine (IC50 = 1.3 ± 0.3 × 10−4 M) and serotonin (IC50 = 8.0 ± 1.4 × 10−5 M) in a non-selective manner. Furthermore, caulerpine concentration-dependently inhibited serotonin-induced cumulative contractions (pD′2 = 4.48 ± 0.08), shifting the curves to the right with Emax reduction and slope of 2.44 ± 0.21, suggesting a noncompetitive antagonism pseudo-irreversible. The alkaloid also relaxed the ileum pre-contracted by KCl (EC50 = 9.0 ± 0.9 × 10−5 M) and carbachol (EC50 = 4.6 ± 0.7 × 10−5 M) in a concentration-dependent manner. This effect was probably due to inhibition of Ca2+ influx through voltage-gated calcium channels (CaV), since caulerpine slightly inhibited the CaCl2-induced contractions in depolarizing medium without Ca2+, shifting the curves to the right and with Emax reduction. According to these results, the spasmolytic effect of caulerpine on guinea pig ileum seems to involve inhibition of Ca2+ influx through CaV. However, other mechanisms are not discarded.  相似文献   
123.
Anatomical, behavioral, histological, endocrinological, and cytogenetic characteristics were determined in a horned intersex goat. Histology of the gonads confirmed that the goat was a true hermaphrodite. Cytogenetic analysis showed that it was a chimera (60XX/60XY). Use of laparoscopy allowed determination of characteristics of the internal gonads.  相似文献   
124.
Twelve multiparous, cycling, lactating Holstein-Friesian cows were synchronised with prostaglandin F(2alpha) and treated with either 2.5 mg carazolol or saline. There were no differences between the peripheral blood concentrations of oestradiol or progesterone, but in the cows treated with carazolol the periovulatory surge of luteinising hormone was delayed, and oestrous behaviour was expressed later than in the control cows.  相似文献   
125.
Genetic typing of classical swine fever virus   总被引:18,自引:0,他引:18  
Three regions of the classical swine fever virus (CSFV) genome that have been widely sequenced were compared with respect to their ability to discriminate between isolates and to segregate viruses into genetic groups. Sequence data-sets were assembled for 55 CSFVs comprising 150 nucleotides of the 5' non-translated region, 190 nucleotides of the E2 envelope glycoprotein gene and 409 nucleotides of the NS5B polymerase gene. Phylogenetic analysis of each data-set revealed similar groups and subgroups. For closely related viruses, the more variable or larger data-sets gave better discrimination, and the most reliable classification was obtained with sequence data from the NS5B region. No evidence was found for intertypic recombination between CSFVs. A larger data-set was also analysed comprising 190 nucleotides of E2 sequence from 100 CSFVs from different parts of the world, in order to assess the extent and global distribution of CSFV diversity. Additional groups of CSFV are evident from Asia and the nomenclature of Lowings et al. (1996) [Lowings, P., Ibata, G., Needham, J., Paton, D., 1996. J. Gen. Virol. 77, 1311-1321] needs to be updated to accommodate these. A tentative assignment, adapting rather than overturning the previous nomenclature divides CSF viruses into three groups with three or four subgroups: 1.1, 1.2, 1.3; 2.1, 2.2, 2.3; 3.1, 3.2, 3.3, 3.4. The expanding data-base of CSFV sequences should improve the prospects of disease tracing in the future, and provide a basis for a standardised approach to ensure that results from different laboratories are comparable.  相似文献   
126.
We evaluated recruitment of larvae of catarina scallop, Argopecten ventricosus, in the area of Puerto Peñasco, NE Gulf of California. We moored artificial collectors in six sites from June 2007 to August 2008 and replaced them every 2 months. We used monthly (July 2002–September 2011) sea surface temperature (SST, °C) and surface chlorophyll‐a concentration (SSChl, mg m?3) Aqua/MODIS satellite data to describe seasonal environmental behaviour study area. Also, we recorded bottom temperature at each site every 4 h, and every 2 months measured sea surface salinity, temperature and dissolved oxygen. We used a repeated measures anova to evaluate differences in the number of recruited spat between main factors, and analysed the presence of multimodal spat shell size frequency distributions. Overall, spat recruitment was negatively correlated with seawater temperature and showed higher spat recruitment abundances throughout winter, which is the season with the highest surface chlorophyll a concentration. We estimated multimodal shell size frequency distributions characterized by more than one modal size. The natural collection of A. ventricosus spat on artificial collectors in the area can be successfully performed over a protracted period (November–December to May–June). Our results extend the area where collection of A. ventricosus spat can be successful.  相似文献   
127.
The cortisol response to glucocorticoid intervention has, in spite of several studies in horses, not been fully characterized with regard to the determinants of onset, intensity and duration of response. Therefore, dexamethasone and cortisol response data were collected in a study applying a constant rate infusion regimen of dexamethasone (0.17, 1.7 and 17 μg/kg) to six Standardbreds. Plasma was analysed for dexamethasone and cortisol concentrations using UHPLC‐MS/MS. Dexamethasone displayed linear kinetics within the concentration range studied. A turnover model of oscillatory behaviour accurately mimicked cortisol data. The mean baseline concentration range was 34–57 μg/L, the fractional turnover rate 0.47–1.5 1/h, the amplitude parameter 6.8–24 μg/L, the maximum inhibitory capacity 0.77–0.97, the drug potency 6–65 ng/L and the sigmoidicity factor 0.7–30. This analysis provided a better understanding of the time course of the cortisol response in horses. This includes baseline variability within and between horses and determinants of the equilibrium concentration–response relationship. The analysis also challenged a protocol for a dexamethasone suppression test design and indicated future improvement to increase the predictability of the test.  相似文献   
128.
The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving (−30 days) induced by a differential nutritional management, parity and week of lactation (WOL) on milk yield and composition, and milk casein and fatty acid composition. Primiparous and multiparous Holstein cows with high BCS (PH, n = 13; MH, n = 9) and low BCS (PL, n = 9; ML = 8) under grazing conditions were sampled at WOL 2 and 8 (before and after peak of lactation). Milk yield was greater in multiparous than in primiparous cows and tended to decrease from WOL 2 to 8 only in ML cows. Milk protein, fat and casein yields were greater in multiparous than in primiparous cows and decreased from WOL 2 to 8. Milk casein concentration in milk protein was greater in MH cows than in ML, PH and PL cows at WOL 2. Milk κ‐casein was greater, and β‐casein was less in multiparous than in primiparous cows. As lactation progressed, proportion of casein fractions were not altered. Only κ‐casein fraction was affected by BCS at −30 days as PL showed a higher concentration than PH. The de novo (4:0–15:1) and mixed‐origin fatty acids (16:0–16:1) in milk fat increased, whereas preformed fatty acids (≥17:0) decreased from WOL 2 to 8. Saturated (SAT) fatty acids tended to be greater and monounsaturated fatty acids (MUFA) were less in multiparous than in primiparous cows. High‐BCS cows had greater concentrations of polyunsaturated (PUFA), conjugated linoleic acid (CLA) as well as n‐6 and n‐3 fatty acids in milk fat than low‐BCS cows. The results indicate that casein and fatty acid fractions in milk were affected by parity and may be modified by a differential nutritional management during the pre‐calving period (BCS at −30 days) in cows under grazing conditions.  相似文献   
129.
In the present work sub- and supercritical extraction conditions using carbon dioxide were studied in order to obtain extracts with different compositions from the green microalgae Dunaliella salina. Different compositions of beta-carotene isomers were identified in the extracts by using HPLC-DAD. Also, antioxidant activity of the extracts was measured using a TEAC assay. An experimental design was applied considering two factors, extraction pressure and temperature, in a wide range of values, trying to maximize the extraction yield. Higher yields were obtained at high pressures and low temperatures, that is, at higher CO2 densities. Attempts were made to correlate the antioxidant activity of the extracts with their chemical composition by means of principal component analysis. A certain relationship was found between their antioxidant activity and the isomeric composition of beta-carotenes. As a result, an original equation is proposed to predict the antioxidant activity of extracts from D. salina in terms of the ratio 9-cis-beta-carotene/all-trans-beta-carotene, the concentration of alpha-carotene, and, especially, the concentration of 9-cis-beta-carotene.  相似文献   
130.
The use of poultry manure or goat/sheep manure in the co-composting of the two-phase olive-mill cake “alperujo” (ALP) with olive leaf (OL) is compared by studying organic-matter mineralization and humification processes during composting and the characteristics of the end products. For this, two different piles (P1 and P2) were prepared using ALP with OL mixed with poultry manure (PM) and goat/sheep manure (GSM), respectively, and composted by the turned windrow composting system. Throughout the composting process, a number of parameters were monitored, such as temperature, pH, electrical conductivity (EC), organic matter (OM), OM losses, total organic carbon (Corg), total nitrogen (Nt), Corg/Nt ratio, and the germination index (GI). In both piles, the temperature exceeded 55 °C for more than 2 weeks, which ensured maximum pathogen reduction. Organic-matter losses followed a first-order kinetic equation in both piles. The final composts presented a stabilized OM and absence of phytotoxins, as observed in the evolution and final values of the Corg/Nt ratio (Corg/Nt < 20) and the germination index (GI > 50 percent). Therefore, composting can be considered as an efficient treatment to recycle this type of waste, obtaining composts with suitable properties that can be safely used in agriculture.  相似文献   
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