d24-hour changes in circulating prolactin, follicle-stimulating hormone, luteinizing hormone and testosterone in male rats subjected to social isolation     

Esquifino AI  Chacón F  Jimenez V  Reyes Toso CF  Cardinali DP 《Journal of circadian rhythms》2004,2(1):1

BACKGROUND: This work analyzes the effect of social isolation (a mild stressor) on the 24-h variation of pituitary-testicular function in young Wistar rats, assessed by measuring circulating levels of prolactin, FSH, LH and testosterone. METHODS: Animals were either individually caged or kept in groups (4-5 animals per cage) under a 12:12 h light-dark cycle (lights on at 0800 h) for 30 days starting on day 35 of life. Rats were killed at 4-h intervals during a 24-h cycle, beginning at 0900 h. RESULTS: Isolation brought about a decrease in prolactin, LH and testosterone secretion and an increase of FSH secretion. In isolated rats the 24-h secretory pattern of prolactin and testosterone became modified, i.e., the maximum in prolactin seen in control animals at the beginning of the activity span was no longer detected, whereas the maximum in circulating testosterone taking place at 1700 h in controls was phase-delayed to 2100 h in isolated rats. CONCLUSION: Social isolation affects the 24-h variation of pituitary-testicular function in young rats. Secretion of prolactin, LH and testosterone decreases, and secretion of FSH increases, in isolated rats. The maximum in prolactin seen in group-caged rats at the beginning of the activity span is not observed in isolated rats. The maximum in circulating testosterone taking place at the second part of the rest span in controls is phase-delayed to the light-dark transition in isolated rats.  相似文献   

The Effect of Hypertensin on the Inactivation of Oxytocin by the Serum of Pregnant Women     

Croxatto H  Croxatto R  Reyes M 《Science (New York, N.Y.)》1948,108(2815):658-659

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Pharmacokinetic study of enrofloxacin in Nile tilapia (Oreochromis niloticus) after a single oral administration in medicated feed          下载免费PDF全文

J. A. Teles  L. C. Castello Branco  M. Del Bianchi  F. Pilarski  F. G. R. Reyes 《Journal of veterinary pharmacology and therapeutics》2016,39(2):205-208

The objective of this study was to evaluate the disposition kinetics of enrofloxacin (ENR) in the plasma and its distribution in the muscle tissue of Nile tilapia (Oreochromis niloticus) after a single oral dose of 10 mg/kg body weight via medicated feed. The fish were kept at a temperature between 28 and 30 °C. The collection period was between 30 min and 120 h after administration of the drug. The samples were analyzed by high‐performance liquid chromatography with a fluorescence detector (HPLC‐FLD). The ENR was slowly absorbed and eliminated from the plasma (C_max = 1.24 ± 0.37 μg/mL; T_max = 8 h; T_1/2Ke = 19.36 h). ENR was efficiently distributed in the muscle tissue and reached maximum values (2.17 ± 0.74 μg/g) after 8 h. Its metabolite, ciprofloxacin (CIP), was detected and quantified in the plasma (0.004 ± 0.005 μg/mL) and muscle (0.01 ± 0.011 μg/g) for up to 48 h. After oral administration, the mean concentration of ENR in the plasma was well above the minimum inhibitory concentrations (MIC₅₀) for most bacteria already isolated from fish except for Streptococcus spp. This way the dose used in this study allowed for concentrations in the blood to treat the diseases of tilapia.  相似文献   

The consequences of diet limitation in juvenile threespine stickleback: growth,lipid storage and the phenomenon of compensatory growth          下载免费PDF全文

Miguel L. Reyes  John A. Baker 《Ecology of Freshwater Fish》2017,26(2):301-312

Many organisms exhibit compensatory growth (CG), an accelerated growth rate during recovery from periods of low nutrient resources. Despite numerous studies, many aspects of CG, particularly fine‐scale temporal effects early in life, remain poorly understood. We manipulated early‐life feeding regimens in threespine stickleback (Gasterosteus aculeatus) to study compensatory responses in growth rate and lipid storage during the first growing season. Laboratory‐reared stickleback, including ancestral oceanic and derived freshwater populations, were divided into three age‐specific dietary treatment groups – DPR1, DPR2 and DPR3 – which were exposed to a half‐ration nutrient deprivation for 30 days at the onset of 2, 3 and 4 months of age, respectively. We hypothesised that these month‐long periods of nutrient deprivation would result in strong, yet variable CG responses across stickleback populations and dietary treatments following a return to optimal ration levels. The youngest two age classes of fish (DPR1 &and DPR2) exhibited strong CG responses, matching growth rates and lipid generation levels seen in control fish fed an ad libitum diet. The oldest nutrient‐deprived group (DPR3) showed a reduced CG response, with body growth recovering only partially, and lipid levels exhibiting even less recovery. Our results demonstrate that compensatory growth responses in juvenile stickleback depend on the timing of deprivation during the first growing season and further that responses to late‐season deprivation have favoured development of a larger body frame entering the overwintering season over lipid regeneration.  相似文献   

Amoebicidal and giardicidal compounds from the leaves of Zanthoxylum liebmannianun     

Arrieta J  Reyes B  Calzada F  Cedillo-Rivera R  Navarrete A 《Fitoterapia》2001,72(3):295-297

The crude ethanol extract from the leaves of Zanthoxylum liebmannianum exhibited inhibitory effect on the reproduction of trophozoites of Entamoeba histolytica (IC(50)=3.48 microg/ml) and Giardia lamblia (IC(50)=58.00 microg/ml). From this extract, asarinin, hyperin, beta-sitosterol, and beta-sitosterol glucoside were isolated. Among them, asarinin was the most active with IC(50) values of 19.86 microg/ml for E. histolytica and 35.45 microg/ml for G. lamblia. The remaining compounds showed moderate activity against both parasites.  相似文献   

Variable very-high-energy gamma-ray emission from the microquasar LS I +61 303     

Albert J  Aliu E  Anderhub H  Antoranz P  Armada A  Asensio M  Baixeras C  Barrio JA  Bartelt M  Bartko H  Bastieri D  Bavikadi SR  Bednarek W  Berger K  Bigongiari C  Biland A  Bisesi E  Bock RK  Bordas P  Bosch-Ramon V  Bretz T  Britvitch I  Camara M  Carmona E  Chilingarian A  Ciprini S  Coarasa JA  Commichau S  Contreras JL  Cortina J  Curtef V  Danielyan V  Dazzi F  De Angelis A  de Los Reyes R  De Lotto B  Domingo-Santamaría E  Dorner D  Doro M  Errando M  Fagiolini M  Ferenc D  Fernández E  Firpo R  Flix J  Fonseca MV  Font L 《Science (New York, N.Y.)》2006,312(5781):1771-1773

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.  相似文献   

Fortification of milk with calcium: effect on calcium bioavailability and interactions with iron and zinc     

Perales S  Barberá R  Lagarda MJ  Farré R 《Journal of agricultural and food chemistry》2006,54(13):4901-4906

Calcium solubility, dialysability, and transport and uptake (retention + transport) by Caco-2 cells as indicators of calcium bioavailability have been estimated in the in vitro gastrointestinal digests of milk and calcium fortified milk. A significant linear correlation (p < 0.05) was obtained between calcium uptake and the amount of soluble calcium added to the cells, and also between percentage calcium uptake and the calcium measured in the analyzed samples. The solubility, dialysis, transport, and uptake values are higher (p < 0.05) for calcium fortified milks than for nonfortified milks; that is, calcium fortification increases not only calcium content but also its bioavailability. An inhibitory effect of calcium from fortified milks upon iron absorption was found. The observed effect of calcium from fortified milks upon zinc bioavailability depends on the in vitro method used, zinc solubility and dialysis decrease in calcium fortified milks, and percentage zinc uptake remains unchanged.  相似文献   

Bulk milk urea concentrations and their relationship with cow fertility in grazing dairy herds in southern Chile   总被引：2，自引：0，他引：2  

Wittwer FG  Gallardo P  Reyes J  Optiz H 《Preventive veterinary medicine》1999,38(2-3):159-166

Milk urea determination is being used as a broad indicator of protein/energy imbalance in dairy herds. The main purpose of this study was to compare blood and bulk milk urea values in grazing herds, to evaluate their seasonal variation under South Chilean conditions, and to examine their potential relationships with herd fertility. The association between herd blood urea concentration (mean of seven lactating cows) and bulk milk urea concentration (tank containing milk from the previous 24 h) was determined in 21 diary herds. Reference values, seasonal and herd variance, and the frequency of herds with values outside a range of 2.5 to 7.3 mmol/l were determined in bulk milk samples obtained monthly for a period of one year from 82 suppliers at two creameries located in southern Chile. Finally, bulk milk urea was measured every two weeks in samples from 24 herds, and the first service conception rate (FSCR) from 2153 dairy cows was determined. Mean bulk urea concentration was highly correlated with mean herd blood urea concentration (r = 0.95; p < 0.01). Mean urea concentration in the bulk milk samples obtained during one year from 82 herds was 4.9 +/- 1.2 mmol/l, with a range of 1.5 to 11.6 mmol/l. The highest values were found during spring and the lowest values during the summer. There was a high seasonal variation (CV = 13-47%) and between-herd variation (CV = 20-31%). Out of a total of 984 samples, 5.4% had urea values > 7.3 mmol/l and 3.8% had values < 2.5 mmol/l. Of the 82 herds, 27% had values outside the reference interval (2.5-7.3 mmol/l) on two or more occasions. FSCR was lower in herds when the bulk milk urea was > 7.3 mmol/l (50.7%) than in cows, where the urea concentration was < 5.0 mmol/l (73.8%) at the time of insemination. The study concluded that bulk milk urea concentrations provided information similar to herd blood urea concentrations in local grazing dairy herds. There was a high frequency of herds with abnormal values, with large variations between herds and between seasons. Increased milk urea concentrations during spring were associated with lower conception rates.  相似文献   

Interactions between commensal fungi and the C-type lectin receptor Dectin-1 influence colitis     

Iliev ID  Funari VA  Taylor KD  Nguyen Q  Reyes CN  Strom SP  Brown J  Becker CA  Fleshner PR  Dubinsky M  Rotter JI  Wang HL  McGovern DP  Brown GD  Underhill DM 《Science (New York, N.Y.)》2012,336(6086):1314-1317

The intestinal microflora, typically equated with bacteria, influences diseases such as obesity and inflammatory bowel disease. Here, we show that the mammalian gut contains a rich fungal community that interacts with the immune system through the innate immune receptor Dectin-1. Mice lacking Dectin-1 exhibited increased susceptibility to chemically induced colitis, which was the result of altered responses to indigenous fungi. In humans, we identified a polymorphism in the gene for Dectin-1 (CLEC7A) that is strongly linked to a severe form of ulcerative colitis. Together, our findings reveal a eukaryotic fungal community in the gut (the "mycobiome") that coexists with bacteria and substantially expands the repertoire of organisms interacting with the intestinal immune system to influence health and disease.  相似文献   

Genotypic variation for root architecture traits in seedlings of maize (Zea mays L.) inbred lines     

Bharath Kumar  Adel H. Abdel‐Ghani  Jenaro Reyes‐Matamoros  Frank Hochholdinger  Thomas Lübberstedt 《Plant Breeding》2012,131(4):465-478

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