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1.
Humoral and cell-mediated immunity (CMI) to herpesvirus saimiri (HVS), an oncogenic lymphotropic herpesvirus, was studied in squirrel and rhesus monkeys. Natural antibody to HVS was found in five of six squirrel monkeys but there was no evidence of specific CMI directed against HVS. Rhesus monkeys did not show natural antibody or CMI against HVS antigens. Immunization with HVS, however, produced both antibody and specific CMI in the rhesus monkeys, but no CMI developed in the squirrel monkeys. These findings are important in the development of animal models for the treatment of tumors associated with lymphotropic herpesviruses.  相似文献   

2.
Viruses differ from other infectious agents mainly in two respects: (a) they may be generated in the genome of normal cells and, in other instances, reinserted into the genome as proviruses, (b) they may participate in all pathologic processes that form the main subject of immune surveillance and immunity such as infectious diseases, tumourous growth, and, auto-aggressive processes.

Due to intracellular and cell modifying character of virus infection, the immune mechanisms are often unsuccessful in elimination of the agent from the vertebrate organism and may show disturbances contributing to development of a persistent viral disease. As exemplified by two forms of leprosy, intracellular bacteria may also cause ‘slow’ diseases. Their course, in analogy with viral slow diseases, seems to reflect the changed immunological potential of the infected host.  相似文献   


3.
The maintenance of a virus depends on a number of factors, including the duration of infectivity and the size of the available host population. In this work, foot-and-mouth disease virus was shown to persist in individual African buffalo (Syncerus caffer) for up to at least five years; thus, the duration of infectivity is more than adequate to cover the normal periods between calving peaks. In a small isolated free-living population which varied from 30 to 100 buffalo, two immunological types of foot-and-mouth disease virus were maintained for at least 24 years and through several generations.  相似文献   

4.
Canine cell-mediated immunity and its in vitro testing is reviewed. Lymphocyte stimulation tests and the leukocyte migration inhibition test are discussed as corollaries of in vivo cell-mediated immunity. Cloning of progenitor populations, characterization of cell surface markers and DL-A typing for studies of canine immunity are also reviewed.  相似文献   

5.
C57B16 mice were immunized with either live, attenuated TC-83 strain VEE virus vaccine or formalin-inactivated VEE vaccine combined with Bordetella pertussis. The kinetics of specific donor and adoptively-immunized recipient anti-VEE neutralizing antibody responses were studied. Donor mice immunized with either live or inactivated VEE virus vaccine combined with potent adjuvants develop specific anti-VEE IgM and IgG responses as early as 7 days post-immunization. Anti-VEE IgM antibody responses comprise the majority of anti-VEE neutralizing antibody at this early time period. By 14 to 21 days post-immunization, anti-VEE IgG responses predominated. When adoptively-immunized recipients were studied, the anti-VEE IgM to IgG predominance seen in donors early after administration was reversed, and for each time-period studied, recipients' serum anti-VEE antibody class responses consisted principally of IgG rather than IgM antibody. Since T-cells cooperation with B-cells is critical in the IgM-IgG antibody shift, these studies support the critical role T-cells exert in adoptive transfer in a murine model of experimental VEE infection. Furthermore, immunization with either live or inactivated VEE vaccine coupled to a potent adjuvant induce comparable donor and adoptively-immunized recipient anti-VEE antibody class responses.  相似文献   

6.
7.
选用128头健康“杜长大”三元杂交断奶仔猪,随机分为对照组、CuSO4组、纳米蒙脱石(MMT)组和MMT-Cu组,分别饲喂基础日粮(对照组)、基础日粮+78 mg/kg Cu2+(CuSO4.5H2O,相当于MMT-Cu中Cu2+的量)、基础日粮+2.0 g/kgMMT、基础日粮+2.0 g/kgMMT-Cu。结果表明,与对照组相比,MMT-Cu组能显著提高(P<0.05)断奶仔猪的平均日增重、饲料转化效率及小肠绒毛高度、绒毛高度与隐窝深度的比值,显著降低(P<0.05)腹泻率及小肠、结肠内容物中大肠杆菌和沙门氏菌的数量;而MMT组也显著降低(P<0.05)仔猪腹泻率,提高(P<0.05)小肠绒毛高度和绒毛高度与隐窝深度的比值。与MMT组或CuSO4组相比,MMT-Cu组能显著(P<0.05)提高断奶仔猪的平均日增重和饲料转化效率(P<0.05),显著降低了(P<0.05)小肠和结肠内容物中大肠杆菌和沙门氏菌的数量。  相似文献   

8.
The present study investigated the influence of Bacillus subtilis GCB‐13‐001 on growth performance, nutrient digestibility, blood characteristics, faecal microbiota and faecal score in weanling pigs. A total of 120 weaning pigs [(Landrace × Yorkshire) × Duroc; 7.73 ± 0.75 kg (28 days of age)] were randomly allotted into three treatments according to their initial body weight (BW) and gender in a 6‐week experiment. There were 8 replication pens in each treatment, with five pigs/pen. Dietary treatment groups were as follows: (a) basal diet (CON), (b) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 108 CFU/kg (T1) and (c) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 109 CFU/kg (T2). Days 1 to 7, the BW and ADG with T2 treatment were higher (p < .05) than CON treatment, as well as F:G showed trends in linear reduction (p < .1). Days 8 to 21, the BW and ADG were improved (p < .05) in pigs offered T1 and T2 diets compared with CON diet. Days 22 to 42, BW and ADG were higher (p < .05) in pigs fed T2 diet than CON and T1 diets, and the pigs fed T1 diet had higher BW than CON treatment. Overall, the ADG with the T2 treatment was higher (p < .05) than that with the T1 and CON treatments, and pigs offered T1 treatment had higher (p < .05) ADG than CON treatment. Moreover, F:G ratio were significantly decreased (p < .05) by T2 treatment compared with CON treatment. The faecal Lactobacillus counts were improved, and E. coli counts were reduced (p < .05) in pigs fed T2 diet compared with CON at the end of the experiment. In conclusion, supplementation of 0.1% Bacillus subtilis GCB‐13‐001 1 × 109 CFU/kg has shown a beneficial effect in improving BW, increase ADG, decrease F:G ratio.  相似文献   

9.
In Korea, several outbreaks of low pathogenic AI (H9N2) viral infections leading to decreased egg production and increased mortality have been reported on commercial farms since 1996, resulting in severe economic losses. To control the H9N2 LPAI endemic, the Korea Veterinary Authority has permitted the use of the inactivated H9N2 LPAI vaccine since 2007. In this study, we developed a killed vaccine using a low pathogenic H9N2 AI virus (A/chicken/Korea/ADL0401) and conducted safety and efficacy tests in commercial layer farms while focusing on analysis of factors that cause losses to farms, including egg production rate, egg abnormality, and feed efficiency. The egg production rate of the control group declined dramatically 5 days after the challenge. There were no changes in feed consumption of all three groups before the challenge, but rates of the control declined afterward. Clinical signs in the vaccinated groups were similar, and a slight decline in feed consumption was observed after challenge; however, this returned to normal more rapidly than the control group and commercial layers. Overall, the results of this study indicate that the safety and efficacy of the vaccine are adequate to provide protection against the AI field infection (H9N2) epidemic in Korea.  相似文献   

10.
The aims of this study were to examine whether mouflons exposed to constant long and short day photoperiods are able to exhibit an annual cycle of hair growth and moult, and prolactin (PRL) secretion. Mouflon ewes were assigned to three groups of treatment. Ewes were maintained, either under natural photoperiod (control, n=9), or received a series of subcutaneous melatonin implants from December to April (n=8), or were exposed to a constant long day photoperiod (16-h light:8-h dark; 16L:8D) during 18 months (n=7). Blood was collected weekly to determine PRL concentrations, and hair samples were clipped weekly from the base of the neck to measure the length of predominant hair. Under constant long days and with melatonin implants, mouflons expressed an annual rhythm of PRL secretion, even though these treatments modified the times of rise or falling of PRL concentrations throughout the year. Hair growth initiation was almost coincident with the summer solstice in both control and melatonin-implanted mouflons but occurred two months earlier in long day hold mouflons (P<0.001). Long day hold mouflons had a lower hair growth rate than control and melatonin-implanted mouflons (P<0.001), and at the end of the experiment, a shorter hair length (3.4±0.24 cm; P<0.01) than control (4.3±0.17 cm), and melatonin-implanted mouflons (4.2±0.12 cm). Our data support the conclusion that in mouflon, an endogenous circannual rhythm of PRL secretion exists, and that the seasonal cycle of hair growth and moult appears to depend, at least in part, on circulating levels of PRL.  相似文献   

11.
We investigated the effects of rice feeding on growth performance and protein (amino acids) metabolism of weanling piglets. In all, 16 weanling piglets with an average initial weight of 7.5 kg were divided into two groups. One group was fed a corn‐soybean meal‐based diet, and the other was fed a rice‐soybean meal diet, containing around 46% of corn or rice, respectively. A two‐week growth trial was conducted. The average daily gain (p = .025) and feed efficiency (p = .011) in rice‐fed piglets were significantly higher than those in corn‐fed piglets. Liver lysine‐ketoglutarate reductase activity tended to be lower (p = .073) in rice‐fed piglets than in corn‐fed piglets. Plasma urea nitrogen concentration in rice‐fed piglets was significantly lower than that in corn‐fed piglets. Plasma glucose and insulin concentrations were significantly higher in rice‐fed piglets than in corn‐fed piglets. Plasma‐free valine, isoleucine, and tryptophan concentrations were significantly higher in rice‐fed piglets than in corn‐fed piglets. In contrast, plasma histidine concentration was significantly lower in rice‐fed piglets than in corn‐fed piglets. Overall, these results show that rice feeding improves the growth performance and affects the protein (amino acids) metabolism in weanling piglets.  相似文献   

12.
穿心莲对肉鸡淋巴细胞活性及白细胞吞噬功能影响   总被引:7,自引:0,他引:7  
试验肉鸡于1日龄随机分为7个试验组,A组为1%超微粉;B组为2%超微粉;C组为0.2%浓缩颗粒(1g浓缩颗粒相当于5g生药);D组为0.4%浓缩颗粒;E组为1%浓缩颗粒;F组为2%细粉;G组为不加中药的空白对照在试验的第14、21、28、35、42天分别采血,进行指标测定,观察不同剂型穿心莲对肉鸡细胞免疫的影响试验结果表明,穿心莲对肉鸡淋巴细胞活性及白细胞活性(吞噬率和吞噬指数)有显著的提高作用(P〈0.05),同时,穿心莲超微粉和浓缩颗粒提高细胞免疫的效果优于细粉;相同剂量下,超微粉的效果有优于浓缩颗粒的趋势。  相似文献   

13.
Different times and temperatures of the 1st phase incubation of the complement fixation test (CFT) were used. It was found that a similar decrease in complement (C′) activity occurred after 2 h at 37°C, after 8 h at 20°C and after 18 h at 4°C. Simultaneously, in the same periods a double increase in standard serum titre at 4 and 20°C was noted in comparison with titre at 37°C. This increase of sensitivity of the CFT at 4 and 20°C appeared to be a simulating one and resulted from the different pattern of reaction in each temperature in the block titration of antigen. The positive reactions in the range from the lowest to the highest dilutions of antigen were appearing and increasing and then disappearing in sequence at 4, 20 and 37°C, creating the typical C′ fixation area for each temperature. Similar results were obtained in four different C′ fixation techniques, most frequently used in diagnosis of animal brucellosis. On the basis of our own examination results and literature data the warm and short C′ fixation (37°C, 30 min) was chosen in the standard technique of the CFT used in routine diagnostic survey for animal brucellosis in Poland.  相似文献   

14.
Polyphenolic compounds are widely distributed in the plant kingdom and display a variety of biological activities, including chemoprevention and growth inhibition of tumours. Propolis contains a conglomerate of polyphenolic compounds. We investigated the effect of propolis and polyphenolic compounds, components of propolis, on the growth and metastatic potential of a transplantable mammary carcinoma (MCa) of the mouse. Metastases in the lung were generated by 2 x 10 tumour cells injected intravenously (i.v.). A water-soluble derivative of propolis (WSDP) and the polyphenolic compounds (caffeic acid (CA) and caffeic acid phenethyl ester (CAPE)) were given to mice perorally before or after tumour cell inoculation. WSDP, CA and CAPE reduced the number of metastases in the lung. This implies that the antitumour activities of the compounds used in these studies are mostly related to the immunomodulatory properties of the compounds, their cytotoxicity to tumour cells, and their ability to induce apoptosis and/or necrosis.  相似文献   

15.
Growth differentiation factor-9 (GDF-9) and bone morphogenetic proteins (BMPs), comprise the largest subgroups of ligands in the TGF-β superfamily, and have been shown to be involved in follicle development in mammals. However, whether these factors are involved in folliculogenesis in pigs is still unknown. The present study was performed to determine the relationships between early folliculogenesis and the expression of GDF-9 and BMP (BMP-4, -5 and -6) mRNAs in neonatal pigs. Ovaries were removed at 5, 16, 28 and 39 days after birth to examine the follicular population (the right ovary of each animal) and to detect mRNA expression (the left ovary of each animal). Primordial follicles accounted for >80% of the ovarian follicles from 5 days until 39 days after birth. A marked increase in primary follicles and the appearance of secondary follicles were observed in the ovaries at 28 days after birth. BMP-4, -5, and -6 and GDF-9 mRNAs were expressed by ovaries at 5-, 16-, 28- and 39-day-old pigs. The peak expression of BMP-4, -5, and -6 and GDF-9 mRNAs was observed in the ovaries at 5, 39, 28 and 16 days, respectively, after birth. These data demonstrate that folliculogenesis in piglets might be controlled by the interaction with these factors. We conclude that BMPs and GDF-9 may have distinct functions in several stages of follicle development in neonatal pig ovaries.  相似文献   

16.
The isothermal and chimeric primer-initiated amplification of nucleic acids (ICAN) is a new isothermal DNA amplification method composed of exo Bca DNA polymerase, RNaseH and DNA–RNA chimeric primers. We detected invA of Salmonella from chicken carcasses, egg yolk and cattle fecal samples. Fifty-three of 59 isolates were invA-positive in ICAN-chromatostrip detection. The result was consistent with those obtained by standard PCR. Salmonella invA was detected in 12 of 14 carcass rinses by ICAN, while in 7 of 14 rinses by standard PCR. These results indicate that ICAN is an efficient, sensitive and simple system to detect invA of Salmonella species in developing countries such as Zambia.  相似文献   

17.
Fifty-one treponemas were isolated from pigs. Twenty-three isolates with typical morphology and growth characteristic were beta hemolytic, enteropathogenic, produced indole and with exception of three strains did not ferment fructose. These strains were classified as typical T. hyodysenteriae and were usually isolated from pigs with symptoms of mucohemorrhagic diarrhoea. The seventeen other isolates were weakly beta hemolytic after 48 h incubation, enteropathogenic, 12 out of 17 produced indole, 10 out 17 fermented fructose. These strains were usually isolated from pigs with symptoms of gray-green diarrhoea and classified as T. hyodysenteriae 2 biotype or intermediate type. They may be compared with Treponema sp. isolated by Taylor et al. Eleven non enteropathogenic strains showed typical characteristic for T. innocens. Gas chromatography analysis of the fatty acids production from glucose, showed that all isolated treponemas produced acetate and butyrate. Typical T. hyodysenteriae produced additionally propionate. Strains of T. hyodysenteriae biotype 2 produced propionate or isobutyrate as well.  相似文献   

18.
This study was conducted to evaluate the effects of dietary soapnut (Sapindus mukorossi) shell powder (SSP), a cheap source of saponins, on growth performance, immunity, serum biochemistry and gut health of broiler chickens. The experimental design was 4×2, employing four saponin levels (0, 100, 150 and 200 mg/kg diet), each provided for two time durations (0–42 day and 21–42 day) resulting into eight dietary treatments. Results revealed no significant effect of dietary saponins on body weight gain, feed intake and feed conversion ratio of birds. The abdominal fat percentage, heterophil to lymphocyte ratio, serum cholesterol and triglyceride levels, faecal total plate count, coliform count and E. coli count decreased (p < .05) progressively with increasing saponin levels and lower values were observed at 150 mg and 200 mg saponin levels. Significant improvement of cell‐mediated and humoral immune response was observed in birds fed 150 mg and 200 mg saponin compared to control. The serum glucose concentration was significantly (p < .05) higher in control group compared to other groups. No significant effects of dietary saponin were observed on carcass characteristics, faecal Lactobacillus count, intestinal histomorphometry and cost economics of broiler chicken production. Thus, dietary saponins at 150 mg/kg diet as SSP for three weeks (21–42 days) was optimum for better immunity and welfare of birds without adverse effects on the growth performance.  相似文献   

19.
With purified LT toxin and IgA, specific anti-LT enterotoxin activity was demonstrated in small intestinal contents of 27 pigs. After 60 days of age, rise in intestinal LT antitoxin titer was observed. Feeding LT containing E. coli antigen increased LT antibody levels in the intestinal secretions, but decreased antibody titers in sera. In post-weaning E. coli diarrhea LT antibody levels in intestinal secretions and sera decreased significantly. This phenomenon can be related to the occurrence of the frequently observed post-weaning E. coli diarrhea.  相似文献   

20.
To study the effect of vitamin E (VE), copper (Cu) and zinc (Zn) supplementation on the in vitro phagocytic activity (PA) and lymphocyte proliferation response (LPR) of blood neutrophils and lymphocytes, thirty Sahiwal pregnant cows (six in each group) in their late gestation at 30 days before the expected date of calving were selected from the NDRI experimental herd and supplemented with various micronutrients from 30 days before calving to 45 days after calving. Cows were supplemented individually with VE (1000 IU/cow/day), Cu (20 ppm/cow/day) and Zn (80 ppm/cow/day) and also with a combination of VE, Cu and Zn to study cumulative effect of all micronutrients. One group without any supplementation acted as a control. Blood neutrophils and lymphocytes were isolated and studied for their PA and LPR. Supplementation of micronutrients like VE, Cu, Zn and a combination of all these nutrients significantly (p < 0.01) increased the PA of experimental cows as compared to control (unsupplemented) cows during the pre‐partum period. During post‐partum, all the micronutrients (VE, Cu, Zn and their combination) showed a significant (p < 0.01) increase in the PA of experimental cows as compared to control cows. Of all the groups, significant (p < 0.01) and maximum PA was observed in the combination group followed by Zn‐supplemented group during both the pre‐ and post‐partum period. A significant (p < 0.01) increase in LPR of B lymphocytes was observed in combination‐supplemented group during the pre‐partum period and during both the pre‐ and post‐partum period in the Cu‐supplemented group.  相似文献   

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