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排序方式: 共有130条查询结果,搜索用时 265 毫秒
1.
JS Munday H Bentall D Aberdein M Navarro FA Uzal S Brown 《New Zealand veterinary journal》2020,68(4):242-246
ABSTRACTCase history and clinical findings: A flock of 20 sheep was kept within three paddocks on a single property. None of the animals in the flock had been vaccinated against any disease for at least three years. Abdominal bloating and haemorrhagic diarrhoea were observed in Lamb 1 at 24 hours-of-age. The lamb subsequently died within an hour of the onset of clinical signs. Lamb 2 was 3-days-old when observed to be recumbent with opisthotonus. The lamb was treated with dextrose, vitamins B1 and B12, and penicillin G, but died 4 hours later.Pathological findings: Examination of Lamb 1 revealed markedly increased gas within the peritoneum and within dilated loops of intestine. The intestines were dark red and contained large quantities of haemorrhagic fluid. Histology of the intestines revealed peracute mucosal necrosis with minimal accompanying inflammation. The intestinal lumen contained cell debris, haemorrhage, and myriad large Gram-positive bacilli. The intestines of Lamb 2 did not appear bloated or reddened. However, multiple fibrin clots were visible within the pericardial sac. Histopathological examination revealed small foci of necrosis within the mucosa of the distal intestine. The necrotic foci were often associated with large numbers of large Gram-positive bacilli.Immunohistochemsitry and molecular biology: Intestinal samples from Lamb 1 were processed for Clostridium perfringens immunohistochemistry, which revealed large numbers of intralesional, positively immunostained rods. Fragments corresponding to the expected sizes for genes encoding alpha, beta, and epsilon C. perfringens typing toxins were amplified by PCR from DNA extracted from formalin-fixed sections of intestine.Diagnosis: Lamb dysentery due to C. perfringens type B.Clinical relevance: C. perfringens bacteria have a worldwide distribution, but disease due to C. perfringens type B has only been diagnosed in a small number of countries and has never been reported in New Zealand or Australia. C. perfringens type B produce both beta toxin and epsilon toxins, therefore both haemorrhagic enteritis and systemic vascular damage can develop. As many animals are exposed to C. perfringens without developing disease, there must be additional unknown factors that resulted in disease in these particular sheep. Vaccines that specifically protect against C. perfringens type B are available and may be recommended for use in smaller non-commercial flocks, as in the present case. 相似文献
2.
Meijer L Hafkamp AM Bosman WE Havinga R Bergman A Sauer PJ Verkade HJ 《Journal of agricultural and food chemistry》2006,54(17):6440-6444
Polybrominated diphenyl ethers are lipophilic persistent organic pollutants (POPs), which accumulate in the environment, leading to human exposure. The compounds exert a negative impact on human health. Strategies to prevent or diminish their accumulation in humans are required. We investigated in rats whether the disposal rate of 14C-labeled tetrabromodiphenyl ether (BDE-47) could be enhanced by increasing fecal fat excretion through dietary treatment with nonabsorbable fat (sucrose polyester, SPE). As compared to control rats, SPE treatment increased fecal excretion rates of fat (+188%, p < 0.05) and 14C-BDE-47 (+291%, p < 0.05). On the basis of biliary secretion and fecal excretion rates of 14C-BDE-47, SPE effectively inhibited the enterohepatic circulation of 14C-BDE-47. In conclusion, dietary supplementation of nonabsorbable fat can enhance excretion of hydrophobic POPs by interruption of their enterohepatic circulation. Our data indicate that this strategy could decrease concentrations of hydrophobic POPs in the human body and thereby their impact on human health. 相似文献
3.
The mechanism that controls the proportion of cannabichromene (CBC), a potential pharmaceutical, in the cannabinoid fraction
of Cannabis sativa L. is explored. As with tetrahydrocannabinol (THC) and cannabidiol (CBD), CBC is an enzymatic conversion product of the precursor
cannabigerol (CBG). CBC is reported to dominate the cannabinoid fraction of juveniles and to decline with maturation. This
ontogeny was confirmed in inbred lines with different mature chemotypes. A consistent CBC presence was found in early leaves
from a diverse clone collection, suggesting that CBC synthase is encoded by a fixed locus. Morphological variants possessing
a ‘prolonged juvenile chemotype’ (PJC), a substantial proportion of CBC persisting up to maturity, are presented. PJC is associated
with a reduced presence of floral bracts, bracteoles, and capitate-stalked trichomes. Genetic factors causing these features
were independent of the allelic chemotype locus B that was previously postulated and regulates THC and CBD synthesis and CBG accumulation. In contrast to previously described
Cannabis chemotypes, the cannabinoid composition of PJCs showed plasticity in that reduced light levels increased the CBC proportion.
The ability of PJC plants to enable the production of pharmaceutical raw material with high CBC purity is demonstrated. 相似文献
4.
5.
Kessel GJ de Haas BH Lombaers-van der Plas CH Meijer EM Dewey FM Goudriaan J van der Werf W Köhl J 《Phytopathology》1999,89(10):868-876
ABSTRACT A technique was developed to localize and quantify the internal mycelial colonization of necrotic leaf tissue of cyclamen (Cyclamen persicum) or lily (Lilium) by pathogenic Botrytis spp. and the antagonist Ulocladium atrum. This technique allows investigation of competitive substrate colonization by both fungi, which is a key process for biological control of Botrytis spp. by U. atrum. A combination of differential fluorescent labeling and image analysis was applied on cryostat sections of necrotic leaf tissue. Botrytis mycelium was labeled specifically by indirect immunofluorescence using a monoclonal antibody specific for Botrytis spp. And an antimouse fluorescein conjugate. Wheat germ agglutinin conjugated to the fluorochrome TRITC was used to label mycelium of both fungi. Image analysis was used to measure the relative surface area of the cryostat section covered by fluorescing hyphae of Botrytis spp. and by fluorescing hyphae of both fungi. A mathematical conversion was derived and used to calculate the relative mycelial volume of each fungal species in the necrotic tissue based on the measured relative surface areas. Temporal aspects of substrate colonization were studied in a short time series. An analysis of components of variance provided insight into spatial colonization patterns for the fungal species involved and allowed the design of efficient sampling strategies for future experiments. 相似文献
6.
It has been hypothesized that the decrease in fertility of dairy cows is related to the increase in milk yield and associated with fatty liver and increased vulnerability for both infection and metabolic diseases. To elucidate the mechanisms behind this complex of health and reproductive problems an Animal Model, based on overfeeding in the dry period, has been developed. In an experiment carried out in 1996 sixteen animals were fed 119 MJ/d net energy to lactation (NEL) (experimental group) and another sixteen just 49 MJ/d NEL (control group) in the last 8 weeks before parturition. During lactation the cows from both groups were given the lactation ration ad libitum. After parturition both groups differed significantly in level and duration of the NEB, in weight loss, increased concentrations of NEFAs and bHBB in the blood and TAG in the liver. Although the insulin level was lower in the experimental animals during the first week, the difference was not significant. The number of ovulations within the first 100 days pp was significant lower in the experimental group and was related to depth and duration of the NEB and the weight loss: more NEB leads to less ovulations. The interval partus-le ovulation was also significant different but related to the TAG level in the liver: more TAG leads to a longer interval. The experimental group with the fatty liver suffered more incidenses of metabolic diseases. It has been concluded that the Model leads to a severe NEB, to Fatty Liver and to more incidences of diseases. Both the NEB and the fatty liver influence the fertility of the cows pp and it can not be excluded that some diseases have an effect too. More studies are planned to unravel the factors that affect the fertility of high yielding cows. 相似文献
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9.
Variation of fiber types in the triceps brachii, longissimus dorsi, gluteus medius, and biceps femoris of horses 总被引:1,自引:0,他引:1
R van den Hoven T Wensing H J Breukink A E Meijer T A Kruip 《American journal of veterinary research》1985,46(4):939-941
The distribution of type-I and type-II fibers in 9 different parts of the musculi triceps brachii, longissimus dorsi, gluteus medius, and biceps femoris was studied to determine whether biopsies from these muscles give reliable information. All 4 investigated muscles were not homogeneous in their fiber-type distribution. Large differences existed among different muscle parts. The percentage of type-I fibers increased toward the deeper and cranial parts of the muscles. In the same zone of the gluteus muscle, differences of 30% were found for type-I fibers. Therefore, results obtained by biopsies of muscles must be interpreted with caution. 相似文献
10.
This paper aims to clarify the genetic mechanism that is responsible for the accumulation of cannabigerol (CBG) in certain
phenotypes of Cannabis sativa L. CBG is the direct precursor of the cannabinoids CBD, THC and CBC. Plants strongly predominant in CBG have been found in
different fibre hemp accessions. Inbred offspring derived from one such individual were crossed with true breeding THC predominant-
and CBD predominant plants, respectively. The segregations in the cross progenies indicate that CBG accumulation is due to
the homozygous presence of a minimally functional allele, tentatively called B0, at the single locus B that normally controls the conversion of CBG into THC (allele BT) and/or CBD (allele BD). The fact that CBG accumulating plants have so far been found in European fibre hemp populations that are generally composed
of BD/BD plants, and the observation that the here investigated B0 allele possesses a residual ability to convert small amounts of CBG into CBD, make it plausible that this B0 is a mutation of normally functional BD. Therefore, B0 is considered as a member of the BD allelic series encoding a CBD synthase isoform with greatly weakened substrate affinity and/or catalytic capacity. 相似文献