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11.
Meyerholz DK Stabel TJ Ackermann MR Carlson SA Jones BD Pohlenz J 《Veterinary pathology》2002,39(6):712-720
Salmonella enterica serovar Typhimurium is an important intestinal pathogen in swine. This study was performed to document the early cellular invasion of Salmonella serovar Typhimurium in swine ileum. Ileal gut-loops were surgically prepared in ten 4- to 5-week-old mixed-breed pigs and inoculated for 0-60 minutes. Loops were harvested and prepared for both scanning and transmission electron microscopy (SEM and TEM, respectively). Preferential bacterial adherence to microfold cells (M cells) was seen within 5 minutes, and by 10 minutes bacterial invasion of the apical membrane was seen in M cells, goblet cells, and enterocytes. This multicellular invasion was observed throughout the course of infection. In addition, SEM revealed a specific affinity of Salmonella serovar Typhimurium to sites of cell extrusion. Using TEM, bacteria in these areas were focused in the crevices formed by the extruding cell and the adjacent cells and in the cytoplasm immediately beneath the extruding cell. Our results suggest that early cellular invasion by Salmonella serovar Typhimurium is nonspecific and rapid in swine. Furthermore, the combination of SEM and TEM data suggests that Salmonella serovar Typhimurium may use sites of cell extrusion as an additional mechanism for early invasion. 相似文献
12.
Schoenmakers I Hazewinkel HA Voorhout G Carlson CS Richardson D 《The Veterinary record》2000,147(23):652-660
The skeletal development of three groups of great dane dogs, fed a diet composed according to the published nutritional requirements for dogs (controls) or with increased calcium or calcium and phosphorus content, was examined radiographically, histologically and biochemically. The diets were fed from the time the dogs first began eating food in addition to their dam's milk, until they were 17 weeks old. Thereafter, the calcium and phosphorus intakes of the dogs in the high calcium groups were normalised for a further 10 weeks. The dogs fed the high calcium diet without a proportionally high phosphorus intake became hypercalcaemic and hypophosphataemic, and had severe disturbances in skeletal development, growth, and mineralisation which were typical for rickets. After their calcium intake was normalised the lesions of rickets resolved but osteochondrotic lesions became apparent. The dogs fed the high calcium and phosphorus diet became slightly hypophosphataemic, their growth was retarded, and they had disturbances in skeletal development resembling osteochondrosis, which had only partly resolved after 10 weeks on the normal calcium and phosphorus diet. 相似文献
13.
K Forster CS Galina M Maquivar G Van der Laan R Arnoni A Verduzco 《Reproduction in domestic animals》2007,42(6):566-570
Thirty cyclic, non-suckled Brahman cows were divided into three groups, all of which were synchronized sequentially with CIDR-B and observed continuously for 100 h to determine different behavioural oestrus signs. Twenty-four hours after implant withdrawal, all synchronized cows in the group, together with all other cows displaying oestrus, were subjected to intensive ultrasonographic observations (every 6 h for 120 h) to pinpoint the moment of ovulation. In the first group, oestrus and ovulation response was 60% (6/10), in the second 44% (4/9) showed oestrus and six ovulated, and in the third group oestrus and ovulation were 80% (8/10). Significant differences were observed between the second and third groups (p < 0.05). No differences were observed in the duration of oestrus, time when oestrus was displayed after implant withdrawal, time of ovulation and onset of oestrus, end of oestrus to ovulation, and intensity of oestrus on a point scale. The relationship between duration of oestrus and time of ovulation was r(2) = 0.16. Ovulation, on average, was 32.1 +/- 14.5 h after the onset of oestrus, 22.3 +/- 16.5 h after the end of oestrus, and 91.8 +/- 16.7 after implant withdrawal, although no significant differences were observed. One non-synchronized animal showed oestrous activity in the second group but failed to ovulate. In the third group, 8 animals showed oestrus, 4 with high concentrations of progesterone. Of the other four one ovulated. In conclusion, oestrous behaviour is not necessarily the best marker to predict the time when ovulation takes place due to variation in the length of the oestrous period and the possible integration of non-ovulatory animals into sexually active groups. 相似文献
14.
15.
Z Sánchez MA Lammoglia MA Alarcón JJ Romero CS Galina 《Reproduction in domestic animals》2015,50(4):574-579
The present assay attempts to evaluate the feasibility of using embryo transfer in small community farmers by in vivo study and by modelling the results obtained. From the total of 59 donor cows, 62.7% responded to treatment, with a significant difference (p = 0.002) in the percentage of the response between breeds, being 90.5% (19/21) in Holstein and 47.4% (18/38) in Brahman. A total of 283 embryos were graded as transferable, while 141 as non‐transferable, without difference in the percentage of transferable embryo by breed (p = 0.18). The mean of transferable embryos graded as class I and II was not different between Holstein and Brahman (p = 0.96 and p = 0.92, respectively); besides, no differences were observed in the other grades (non‐transferable). The highest difference in costs, regardless of its quality by breed, was seen in the lower levels of probable fertility of the embryo transferred, even reaching several hundred dollars. When modelling the expected costs for embryo produced and transferred, values can reach nearly $2000.00 when the probable fertility is only 10%. However, when the probable fertility was 60%, embryo cost was close to $300.00. This technology seems to be viable on average or high‐scale systems, having a superovulatory response between 60 and 80% with 4–6 transferrable embryos. Yet, in small‐scale farming, due to the reduced number of donors and/or recipients, the costs surpass the economical feasibility of the technique. 相似文献
16.
Aly KAREN árpád Csaba BAJCSY Rosa MINOIA Rezs? KOVáCS Noelita Melo DE SOUSA Jean-Fran?ois BECKERS János TIBOLD István MáDL Ottó SZENCI 《The Journal of reproduction and development》2014,60(2):162-167
The aim of the present study was to determine the relationship of progesterone (P4),
bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late
embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56)
in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100
Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to
diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of
each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood
sample was collected for assessment of bPAG-1, by using a double-antibody
radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic
examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28
after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy
loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression
analysis, there were no significant relationships between the level of P4 and bPAG-1 at
day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant
relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On
the other hand, a significant relationship (P<0.05) was found between NO level at day
28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at
day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows
but further studies are needed to confirm this. 相似文献
17.
João H Perotta Paulo A Canola Maristela CS Lopes Patrícia M Évora Paulo EB Martinez André Escobar Carlos AA Valadão 《Veterinary anaesthesia and analgesia》2014,41(4):357-364
ObjectiveTo evaluate the effects of intravenous (IV) or intramuscular (IM) hyoscine premedication on physiologic variables following IV administration of medetomidine in horses.Study designRandomized, crossover experimental study.AnimalsEight healthy crossbred horses weighing 330 ± 39 kg and aged 7 ± 4 years.MethodsBaseline measurements of heart rate (HR), cardiac index (CI), respiratory rate, systemic vascular resistance (SVR), percentage of patients with second degree atrioventricular (2oAV) block, mean arterial pressure (MAP), pH, and arterial partial pressures of carbon dioxide (PaCO2) and oxygen (PaO2) were obtained 5 minutes before administration of IV hyoscine (0.14 mg kg?1; group HIV), IM hyoscine (0.3 mg kg?1; group HIM), or an equal volume of physiologic saline IV (group C). Five minutes later, medetomidine (7.5 μg kg?1) was administered IV and measurements were recorded at various time points for 130 minutes.ResultsMedetomidine induced bradycardia, 2oAV blocks and increased SVR immediately after administration, without significant changes in CI or MAP in C. Hyoscine administration induced tachycardia and hypertension, and decreased the percentage of 2oAV blocks induced by medetomidine. Peak HR and MAP were higher in HIV than HIM at 88 ± 18 beats minute?1 and 241 ± 37 mmHg versus 65 ± 16 beats minute?1 and 192 ± 38 mmHg, respectively. CI was increased significantly in HIV (p ≤ 0.05). Respiratory rate decreased significantly in all groups during the recording period. pH, PaCO2 and PaO2 were not significantly changed by administration of medetomidine with or without hyoscine.Conclusion and clinical relevanceHyoscine administered IV or IM before medetomidine in horses resulted in tachycardia and hypertension under the conditions of this study. The significance of these changes, and responses to other dose rates, requires further investigation. 相似文献
18.
19.
We tracked and monitored hurricane Anita over a 5-day period by using the SRI-operated Wide Aperture Research Facility (WARF) high-frequency skywave radar. The WARF-derived positions for Anita agreed to within +/- 19 kilometers of the coincident temporal positions along the National Hurricane Center's smooth track. Hurricane Anita passed near the open ocean-moored buoy EB-71 of the National Oceanic and Atmospheric Administration, and measurements of wind direction, wind speed, and significant wave height made during this period at the WARF and in situ at the buoy showed agreement of 7 degrees , 0.4 meter per second, and 0.5 meter, respectively. The WARF estimates of longshore coastal surface currents showed good agreement with measurements made at a moored current meter. 相似文献
20.
A yeast gene that is essential for release from glucose repression encodes a protein kinase 总被引:120,自引:0,他引:120
The SNF1 gene plays a central role in carbon catabolite repression in the yeast Saccharomyces cerevisiae, namely that SNF1 function is required for expression of glucose-repressible genes. The nucleotide sequence of the cloned SNF1 gene was determined, and the predicted amino acid sequence shows that SNF1 encodes a 72,040-dalton polypeptide that has significant homology to the conserved catalytic domain of mammalian protein kinases. Specific antisera were prepared and used to identify the SNF1 protein. The protein was shown to transfer phosphate from adenosine triphosphate to serine and threonine residues in an in vitro autophosphorylation reaction. These findings indicate that SNF1 encodes a protein kinase and suggest that protein phosphorylation plays a critical role in regulation by carbon catabolite repression in eukaryotic cells. 相似文献