Chemotherapy is assumed to be immunosuppressive; yet to the authors' knowledge, the effects of common chemotherapy protocols on adaptive immune responses in dogs with cancer have not been fully evaluated. Therefore, a study was conducted to evaluate the effects of 2 common chemotherapy protocols on T- and B-cell numbers and humoral immune responses to de novo vaccination in dogs with cancer. Twenty-one dogs with cancer (12 with lymphoma, 9 with osteosarcoma) were enrolled in a prospective study to assess effects of doxorubicin versus multi-drug chemotherapy on adaptive immunity. Numbers of circulating T and B cells were assessed by flow cytometry, and antibody responses to de novo vaccination were assessed before, during, and after chemotherapy. The T- and B-cell numbers before treatment also were compared with those of healthy, age-matched, control dogs. Prior to treatment, dogs with cancer had significantly fewer (P < .05) CD4+ T cells and CD8+ T cells than did healthy dogs. Doxorubicin treatment did not cause a significant decrease in T- or B-cell numbers, whereas treatment with combination chemotherapy caused a significant and persistent decrease in B-cell numbers. Antibody titers after vaccination were not significantly different between control and chemotherapy-treated dogs. These findings suggest that chemotherapy may have less impact on T-cell numbers and ability to mount antibody responses in dogs with cancer than was previously anticipated, though dogs with lymphoma or osteosarcoma appear to be relatively T-cell deficient before initiation of chemotherapy. 相似文献
The organisation of animal populations in social groupings may play a crucial role in the transmission of any infectious disease that requires close contact. The objective of this study was to quantify the contact structure of part of the Heck cattle population in a Dutch nature reserve and its hypothetical effect on the transmission of bovine herpesvirus 1 (BHV1). The contact structure was quantified by observing the number of different animals with whom contact was made (i.e. the number of contactees) within a fixed time period. Two types of behaviour sampling methods, namely focal sampling and scan sampling were used to observe the contact structure. In this study only those contacts between individuals were observed that were assumed to be a proxy measure of an at-risk event for BHV1-infection. Two reproduction ratios (R), i.e. the average number of new cases caused by a typical infected individual, were estimated, one for the observed contact structure and another for a random mixing contact structure. The two reproduction ratios were then compared to study the hypothetical effect on BHV1 transmission.
The overall number of contactees was highest during summer and lowest during winter-spring. The contact structure of the homogeneous population did differ significantly from a random mixing contact structure, resulting in that the variation in the number of contactees was higher than under random mixing. Bulls, young bulls and cows had the highest number of contactees during, respectively, summer, autumn and winter-spring. From the analysis of the contingency tables it was clear that contacts between animal types did not occur at random during summer and autumn. For example, during summer more contacts than expected occurred between bulls and cows. This heterogeneity at animal type level was taken into account in the calculation for R, which resulted for the observed contact structure in higher estimates for R than for the homogeneous population.
When looking at heterogeneity at individual level it was found that during summer almost all individuals were observed together direct or indirect in the same group except for certain bull groups. During autumn and winter-spring almost all individuals were seen together in the same group when considering a long contact period of 14 days but the groups were fallen apart in smaller groups and solitary individuals for a short contact period of 5 days.
It could be concluded that based on the observed contact structure transmission would be favoured most during summer. 相似文献
Immediately after the detection of the first case of BSE in 2001, the Japanese government introduced active surveillance targeting fallen-stock and all cattle slaughtered for human consumption. By the end of 2004, four million animals were tested with rapid tests under the passive and active surveillance. As a result 13 additional cases were detected. I focused on the 1996 birth cohort, in which nine cases of BSE were detected during 2001–2004, and estimated the prevalence of BSE infection of that birth cohort using maximum-likelihood methods. Using the estimated prevalence of infection as an input variable, I calculated the adjusted incidence risk of BSE by different ages and risk subpopulations (clinical-suspects, fallen-stock, sick-slaughter and healthy-slaughter animals). The adjusted incidence risk of BSE in sick-slaughter animals (animals showing clinical signs not compatible with BSE when slaughtered for human consumption) was 18.7 and 4.5–78.4 times higher than the incidence risk in fallen-stock and healthy-slaughter animals, respectively. 相似文献
A 1-year-old heifer from an enzootic bovine leukemia virus (BLV)-free breeding herd was examined for numerous cutaneous plaques on the neck, shoulder, back, perineum, and tail. Impression smears of the skin lesions contained a large population of neoplastic lymphoblastic cells. Hematologic findings included mild anemia, neutrophilia, and lymphocytosis. The serum activity of lactate dehydrogenase (LDH) was moderately increased at admission (4712 U/L), and remained increased despite normal to minimally increased activities of liver- and muscle-specific enzymes. The heifer was serologically negative for BLV. Because of declining condition and poor prognosis, the heifer was euthanized on day 37 after presentation. At necropsy and on histologic examination, epitheliotropic and folliculotropic cutaneous lymphoma, with generalized involvement of lymph nodes and spleen and infiltration of liver and kidney, was diagnosed. Immunophenotyping results (CD79-, CD3+) were consistent with a lymphoma of T-cell origin. We concluded that cutaneous T-cell lymphoma had spread to the other internal organs, and that the neoplasm likely contributed to increased serum LDH activity. 相似文献
Two experiments were conducted to evaluate the efficacy of beta-glucan on commercial broilers. In experiment 1, one hundred and forty-four broiler chicks were employed in a 2x3 factorial design with cage and open floor housing with three levels of beta-glucan viz. 0%, 0.02% and 0.04%. In experiment 2, ninety-six broilers were used with 4 treatments: No beta-glucan and antibiotic (T1), beta-glucan 0.03% (T2), antibiotic (T3), and beta-glucan 0.03% + antibiotic (T4) for 34 d with 3 replicates of 8 chicks each in both studies. During experiment 1 there was no significant effect of the feeding system or the beta-glucan levels on the performance from 0 to 17 d but during 18-34 days birds housed on the open floor had significantly (p<0.0001) higher weight gain compared with those in cages. In experiment 2, no significant effect was noticed on the weight gains when the effect of beta-glucan, antibiotic or their interaction were tested. The retention of dry matter increased in both experiments with beta-glucan supplementation. The CD8 and TCR 1 cells were significantly higher in the 0.04% beta-glucan group at 42 days as compared with the control. It could be concluded that beta-glucan supplementation was beneficial for broilers. 相似文献
Vascular Endothelial Growth Factor (VEGF) and its receptor KDR are involved in the regulation of angiogenesis and are up-regulated in a number of tumours in humans and in particular, breast cancer. We therefore evaluated the prognostic potential of the angiogenetic process in feline and canine mammary carcinomas by the immunohistochemical assessment of VEGF expression and micro vessel density (MVD) quantification and examined the interplay between VEGF and KDR. These variables were related to some relevant clinicopathological parameters and to overall survival (OS). VEGF and KDR expression were evaluated in epithelial, stromal and endothelial compartments in order to identify autocrine and/or paracrine loops. In dogs an increased VEGF expression did not show any statistical correlation with the clinicopathological parameters examined and was not correlated to a poorer prognosis. MVD was found to be significantly correlated to the histologic type (P=0.04), tumour grading (P=0.02), and to the OS (P=0.01). In cats VEGF expression was significantly correlated to tumor grading (P=0.01) and OS (P=0.03), while no significant associations were found between MVD and the other parameters. VEGF and KDR were found to be detected on the epithelial, and/or endothelial and/or stromal cells of the carcinomas in both species, suggesting indications for some possible autocrine and paracrine loops. Our results encourage further studies on the possible prognostic role of VEGF and MVD in canine and feline mammary tumours and on the role of growth factors and their receptors in promoting tumour proliferation and an "angiogenetic shift". The VEGF/KDR system may play a role in malignant transformation and tumor progression. 相似文献
Clinical signs associated with bovine spongiform encephalopathy (BSE) were studied in 1008 casualty slaughter cattle over 30 months of age to compare the results with the BSE status as determined by postmortem tests. The clinical BSE status was assessed using seven different criteria based on various publications. Only one (0.10%) out of 997 casualty slaughter cattle with a matching postmortem test result was positive for BSE. The BSE case was identified by only two case definitions tailored specifically to recumbent cases. The variety and often equivocal definition of clinical signs associated with BSE is reflected by the difference in the criteria that usually identified different animals as BSE suspects. The BSE status may be more difficult to assess in recumbent animals that do not allow a full clinical examination, and BSE may not be suspected if another disease is present that may mask signs of BSE. 相似文献