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1.
Epigallocatechin gallate (EGCg) is the main active component of tea polyphenol and shows several biological activities, such as antimicrobial, antitumor‐promoting, anti‐inflammatory and anti‐oxidative activities. In the present study, the inhibitory effect of EGCg on bovine coronavirus (BCV) propagation in Madin‐Darby bovine kidney (MDBK) cells was investigated. EGCg at concentrations of less than 10 µg/mL did not show any cytotoxicity to MDBK cells. BCV propagation was significantly inhibited by pretreatment of the virus with EGCg (0.5–10 µg/mL) before virus inoculation in dose‐dependent, incubation time‐dependent and temperature‐dependent manners. The antiviral effect of pretreating MDBK cells with EGCg on BCV propagation was much weaker than that of pretreating BCV with EGCg. The hemagglutination activity of BCV was also reduced by EGCg in a dose‐dependent manner. These results demonstrate that EGCg possesses a distinct anti‐BCV activity and strongly suggest that EGCg interferes with the adsorption of BCV to MDBK cells by the interaction of EGCg with BCV particles. EGCg may therefore be a useful candidate for controlling BCV infection more effectively.  相似文献   

2.
A protein A-colloidal gold immunoelectron microscopy (PAG-IEM) technique was developed for the detection of bovine coronavirus (BCV) in the feces and nasal secretions of infected calves. Feces or nasal swab fluids were incubated sequentially with hyperimmune bovine anti-bovine coronavirus serum and protein A-gold, negatively stained, applied to formvar-coated copper grids and viewed using an electron microscope. The PAG-IEM method specifically identified BCV particles and possible subviral particles in feces and nasal-swab fluids from infected calves. The PAG-IEM method did not label other enveloped enteric viruses or morphologically similar fringed particles commonly found in feces. Detection of BCV using PAG-IEM was compared with ELISA and direct immunofluorescence (IF) of nasal epithelial cells by monitoring fecal and respiratory tract shedding of BCV from two experimentally infected and two naturally infected calves from birth to 3 weeks of age. PAG-IEM and ELISA detected shedding of BCV in fecal (4/4 animals) and nasal (3/4 animals) samples for an average of 5.25 days each. The observed agreement of BCV detection by PAG-IEM and ELISA was 85%. PAG-IEM may be a more sensitive immunoassay for the detection of BCV in diagnostic specimens from infected neonatal calves than ELISA. BCV infection of nasal epithelial cells was detected by immunofluorescence in 4/4 calves, persisted for the duration of the study in 2/4 calves and was sporadic in the other two animals. The observed agreement of BCV detection by PAG-IEM and IF was 57%.  相似文献   

3.
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4.
Introduction: Pamidronate has been traditionally used to manage pathologic osteoclastic disorders. In addition to its effects on osteoclasts, pamidronate has also been demonstrated to promote phenotypic maturation and inhibition of proliferation in osteoblasts. Canine osteosarcoma (OSA) consists of malignant, undifferentiated osteoblasts. The objective of this study was to determine if micromolar concentrations of pamidronate could induce malignant osteoblastic differentiation as evaluated by an increase in alkaline phosphatase (ALP) activity and/or osteocalcin (OC) production, two specific markers of normal osteoblastic activity. Methods: Two canine OSA cell lines (HMPOS and COS 31) were used for all experiments. Cells were incubated for 48 or 72 hours with various pamidronate concentrations (0, 0.1, 1, 5, 10, and 20 μM). After incubation, the supernatants were sampled and the relative amounts of viable cells were determined with a cell proliferation assay (Cell Titer 96® AQuous, Promega). An ALP detection kit (Starbright®, Sigma®) was used to measure the ALP activity and an ELISA (Osteocalcin EIA kit, Biomedical Technologies) was used to determine the concentration of osteocalcin in the supernatants. The ALP and osteocalcin values were corrected for the amount of viable cells. Results: Pamidronate induced a dose‐dependent reduction in the number of viable COS 31 and HMPOS cells at both 48 and 72 hours. A dose‐dependent elevation in ALP activity from baseline was observed. At 20 μM, a 2.3‐fold increase was observed for HMPOS at 72 hours, while a 1.43‐fold increase was observed for COS 31 at 72 hours. Very low level (less than 2 ng/ml) of osteocalcin pre‐ and post‐pamidronate treatment was detected for both COS 31 and HMPOS. Conclusion: The data suggests that pamidronate increases alkaline phosphatase activity in canine OSA cells in a dose‐dependent manner. However, cytotoxic assays are needed in order to accurately characterize any concurrent decrease in the number of viable cells. The potential differentiating effect of pamidronate on malignant osteoblasts provides an additional argument for its use in the palliative treatment of OSA.  相似文献   

5.
Influence of isoprinosine on bovine herpesvirus type-1 infection in cattle   总被引：1，自引：0，他引：1  
A study was conducted to determine the in vivo efficacy of isoprinosine (ISO) in calves infected with bovine herpesvirus type-1 (BHV-1). Calves were infected with BHV-1 on day 0 and received ISO daily for 14 days. Clinical signs of disease, shedding of BHV-1, lymphocyte proliferative responses to mitogens, interleukin-2 production, and alveolar macrophage bactericidal activity were monitored during the study. Rectal temperatures were increased (P less than 0.05) in BHV-1 and ISO-BHV-1 calves at days 3 to 7 postinfection (PI). Isoprinosine did not influence BHV-1 shedding in calves. Lymphocyte proliferative responses to phytohemagglutinin (PHA) were lower (P less than 0.01) in BHV-1 calves when compared to control or ISO calves at day 4 PI, but ISO did not ameliorate this effect. Interleukin-2 activity was greater (P less than 0.05) in ISO-BHV-1 calves on days 4 and 8 PI in PHA-stimulated lymphocytes and on day 8 PI in concanavalin A-stimulated lymphocytes when compared to control, ISO or BHV-1 calves. Isoprinosine treatment of BHV-1-infected calves tended to decrease alveolar macrophage bactericidal activity. These data suggest that ISO does not reverse BHV-1 suppression of lymphocyte proliferation, but may enhance IL-2 production in BHV-1 infected calves.  相似文献   

6.
This prospective longitudinal study examined the epidemiology and disease syndrome associated with bovine coronavirus (BCV) infections in a cohort of 8 conventional calves from 0 to 120 days of age, in two dairy herds in Ohio. The periods of respiratory shedding of BCV were determined by direct immunofluorescent (DIF) staining of nasal epithelial cells and ELISA of nasal swab supernatant fluids. The periods of fecal shedding of BCV were determined by ELISA and immunoelectron microscopy (IEM). The isotype-specific antibody titers to BCV in serum (at selected intervals between 0 and 120 days of age) and the post-suckling (24 to 48 h after birth) total immunoglobulin levels were examined by ELISA and zinc sulfate turbidity tests, respectively. Of the 8 calves studied, 4 had evidence of BCV respiratory (by DIF or ELISA) or enteric infections (by IEM or ELISA) in association with diarrhea or rhinitis, even though 7 of 8 calves showed increases in one or more serum antibody isotypes to BCV and 6 of 8 calves showed BCV respiratory or enteric antigen shedding by ELISA. Serological antibody titer increases occurred in 3 calves before 30 days of age and in 4 calves after 30 days of age; two of the latter calves had a second rise in serum antibody titers to BCV after the initial rise. A serological antibody titer increase was not observed in one calf. This suggests that BCV infections may be very common in a closed herd and may occur in older calves, although many may be subclinical and some may be recurrent. There were no statistically significant correlations between total serum immunoglobulin levels or BCV antibody isotype titers in serum (24-48 h after birth) and clinical disease or infection by BCV; however, calves with low levels of IgA BCV antibodies in serum (24-48 h after birth) had a significantly greater average number of days with diarrhea than those calves having high levels of IgA BCV-specific antibodies in serum.  相似文献   

7.
Groups of Swiss white mice weighing 25-28 grams were infected orally with 500, 2,000, 5,000 or 20,000 oocysts of Eimeria falciformis var pragensis. Depression, anorexia, weight loss, diarrhea or dysentery, and dehydration were most pronounced at eight to ten days postinfection. The highest mortality, 31%, occurred in mice infected with 20,000 oocysts. None of the mice infected with 500 oocysts died. The pathological findings were equally severe in mice infected with 5,000 and 20,000 oocysts. The enteric lesions, most pronounced at eight to ten days postinfection, were restricted mainly to the large intestine and consisted initially of both cryptal and absorptive epithelial cell destruction and submucosal edema. These changes were followed in 12 to 24 hours by a transient influx of neutrophils into the lamina propria followed by mononuclear cell infiltration which lasted for five to ten days. As the infective dose decreased, the inflammatory response occurred later and was less extensive. When seen, hemorrhage occurred seven to 11 days postinfection. In 50% of the mice infected with 5,000 and 20,000 oocysts, varying degrees of a nonselective mucosal necrosis were seen at eight to 12 days postinfection. In mice infected with 500 oocysts, mucosal destruction was restricted to the epithelium. Neutrophils predominated when necrosis was extensive, otherwise, mononuclear cells were the main inflammatory cells. Two to three days following necrosis, crypt hyperplasia was marked and mucosal integrity was restored. Ulcers, some of which extended into the submucosa, healed by days 14 to 20. Localized granulomatous colitis, induced by trapped oocysts within the lamina propria, was seen until the experiment was terminated at 25 days postinfection. Infection was followed by lymphoid hyperplasia in the lymph nodes and the spleen.  相似文献   

8.
Two avian and seven mammalian cell lines were evaluated for their application in propagating avian reovirus WVU 2937. Cultures were compared for monolayer-formation time, support of viral replication, passages and postinfection time required for expression of cytopathic effect (CPE), type of CPE, and virus yield. CPE was observed on the first passage with infected egg yolk in primary chicken embryo kidney cells, primary through tertiary chicken embryo liver (CEL) cells, and African green monkey kidney (VERO) cells; on the third blind passage of infected supernatant in Georgia bovine kidney cells, Crandall feline kidney cells, and baby hamster cells; on the fifth blind passage in rabbit kidney cells; and on the tenth blind passage in porcine kidney cells. CPE was not observed after 10 viral passages in rabbit bone-marrow cells. Monolayer formation time and postinfection time for CPE expression occurred sooner, and virus yield was greater, with CEL and VERO cells than with other cell lines.  相似文献   

9.
Sixteen pathogen-free piglets were infected orally with procine enterovirus strain T80 and the cell mediated response to the virus was measured at intervals after infection. Five uninfected piglets were used as controls. Indirect macrophage migration inhibition tests were performed with lymphocytes from blood, ileal lamina propria and mesenteric lymph node. Blood lymphocyte culture supernatants showed no consistent T80 specific on macrophage migration, suggesting the absence of a systemic cell-mediated response. Ileal lamina propria lymphocyte culture supernatants showed irregular migration stimulation. The mesenteric lymph node lymphocyte culture supernatants produced migration inhibition at seven days postinfection, followed by stimulation of migration from ten to 22 days postinfection. Subsequently, migration was again inhibited from 24 to 31 days postinfection. Mesenteric lymph node lymphocyte culture supernatants contained only trace amounts of interferon activity at 28 and 31 days postinfection. It was concluded that the cell mediated responses in this infection were weak and localized and not associated with significant antiviral activity.  相似文献   

10.
An effective culture system for Ehrlichia (Cowdria) ruminantium comb. nov. was first established in 1985 and many stocks were subsequently isolated and propagated in vitro. A notable exception, however, was the Kümm isolate that resisted all attempts at in vitro culture until the successful experiment described here. In one experiment white blood cells were harvested from heparinized blood derived from a sheep infected with the Kümm isolate. The cells were added to DH 82 cells and incubated at 37 degrees C. The high metabolic activity of the DH 82 cells necessitated that cell growth be retarded by the addition of cycloheximide. Colonies were first detected 19 days after culture initiation and, once the cultures were established, they could be passaged every 3 days. Bovine and sheep endothelial cells were readily infected with culture supernatant obtained from the infected DH 82 cells. In a further experiment another sheep was infected, using a higher dose of the same batch of Kümm stabilate, and we attempted to infect several different cell lines: these were DH 82 cells, bovine aorta (BA 886) cells, sheep brain endothelial (SBE 189) cells and sheep fibroblastoid cells (E2). Ten days after culture initiation only the E2 cells had become positive for E. ruminantium. Culture supernatant from the first cultured isolate (Kümm-1) was less virulent for mice than that of the second cultured isolate (Kümm-2) which killed all mice. Upon molecular characterization with E. ruminantium 16S probes we found that Kümm-1 hybridized with a Senegal 16S genotype probe, whereas Kümm-2 hybridized only with an Omatjenne 16S genotype probe. The original stabilate used to infect the sheep hybridized with both probes. These results clearly indicate that two different stocks had been isolated in culture.  相似文献   

11.
Rats heavily infected with larval Taenia taeniaeformis show hyperplasia of the gastric mucosa accompanied by mucous cell proliferation, increase in the level of intragastric pH and hypergastrinemia. Sixty one rats were divided into 2 groups designed as infected (36 rats) and control (25 rats) group. These rats were examined with time course of the infection histopathologically and physiopathologically, during 14-112 days postinfection (DPI). In the infected rats, gastric mucosal hyperplasia began to be observed at 56 DPI, and the structural disturbance of zymogenic units in the corpus and mucous units in the antrum had increased with time. However, the degree of these changes in the antrum was weaker than those in the corpus. Alcianblue and/or PAS-positive cells increased in their numbers with time, and 4 types of cells other than typical surface mucous cell and mucous neck cell were observed by electron-microscopy. However, zymogenic and parietal cells decreased in their number after 56 DPI. Further, the infected rats showed changes in the serum concentration of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, glucose and total protein. Some similarities with Menetrier's disease were discussed.  相似文献   

12.
囊虫病循环抗原检测用于疗效考核   总被引：2，自引：0，他引：2  
分别对 15头囊虫病猪和 15例囊虫病患者治疗前后血清循环抗原 (CA)的变化情况作了观察。用吡喹酮治疗囊虫病猪 15头 ,经剖检证实治愈 13头 ,其中 10头在治疗后 15 d血清中 CA的衰减幅度大于 2 ,治疗 30 d后 13头猪血清 CA的衰减幅度大于 2 (其中 3头猪 CA转阴 ) ,治疗 6 0 d后 CA转阴猪达 10头 ;未治愈的 2头病猪 ,CA一直变化不大。用丙硫咪唑治疗囊虫病患者 15例 ,其中 9例经 1个疗程治愈 ,治疗后 30 d CA的衰减幅度大于 2 ,治疗 6 0 d后 CA全部转阴 ;3例经 2个疗程治愈 ,6 0 d后 CA的衰减幅度大于 2 ,1例转阴 ;2例经 3个疗程治愈 ,治疗 90 d后 CA的衰减幅度大于 2 ;1例严重感染的患者经 6个疗程治疗未治愈 ,其血清中 CA的衰减幅度小于 2。以上结果表明 ,血清 CA的光密度 (D值 )变化能准确反应囊虫在患者体内的生存状态 ,治疗前后 CA的衰减幅度大于 2或 CA消失可作为囊虫病治愈的考核依据。  相似文献   

13.
应用ELISA双抗体夹心法检测囊虫病猪血清中的循环抗原(CA),对CA效价与虫负荷的相关性作了初步观察,发现两者密切相关.轻度感染猪血清CA效价≤000,中度为1000～10000,重度为10000～100000.人工感染病猪血清一般在感染后1周检出CA,于感染后4～5周达高峰;抗体一般于感染后2周检出.这种方法可检出的最小虫负荷约为20个/猪  相似文献   

14.
Sera from 9 dairy herds with epizootic enteritis (winter dysentery) were examined for antibodies to bovine coronavirus (BCV) and bovine virus diarrhoea virus (BVDV). Cows in 8 of the 9 herds seroconverted to BCV alone, while the animals in the ninth herd, which showed severe symptoms of the disease, seroconverted both to BCV and BVDV. The BCV antibodies, which were present in high titres 1 year postinfection, were transferred to the offspring via the colostrum and were then detectable in sera of calves until these were approximately 5 months old. A serological survey of 549 Swedish heifers showed that 61% of the animals were reactors to BCV. The prevalence of seroreactors to BCV was equally distributed over Sweden but was commonly either high or low in herds. In conclusion, BCV is commonly detected in animals suffering from winter dysentery. A co-infection with BVDV appears to aggravate the disease.  相似文献   

15.
以7日龄SPF雏鸡为试验动物,应用细胞培养和免疫酶技术,通过对外周血液免疫球蛋白含量、T和B淋巴细胞数量及其功能的检测,较全面系统地研究了鹅源H5N1亚型中强毒禽流感病毒(AIV)感染SPF雏鸡后,其外周血液上述指标的动态变化。结果发现,SPF雏鸡感染鹅源H5N1亚型AIV后,血清IgG和IgA含量在1~4d显著或极显著低于对照雏鸡(P<0.05或P<0.01),而IgM在病毒感染早期未见显著性差异,随后3种免疫球蛋白含量逐渐回升;血液T淋巴细胞数量显著低于对照雏鸡(P<0.05或P<0.01),而B淋巴细胞在1~5d明显降低(P<0.05或P<0.01);T、B淋巴细胞对ConA或PMA的增殖反应分别于1~8d、1~4d明显低于对照雏鸡(P<0.05或P<0.01)。上述结果表明,AIV感染SPF雏鸡外周血液无论是细胞免疫还是体液免疫功能均呈现一定抑制。  相似文献   

16.
应用组织培养技术及MTT法,对鹅源H5N1型AIV感染雏鸡胸腺、脾脏T细胞增殖功能及IL-2诱生活性进行检测,结果发现:雏鸡感染AIV后,免疫器官T细胞增殖功能和IL-2诱生活性在感染初期较对照雏鸡明显降低,后期有所恢复,表明AIV感染雏鸡细胞免疫受到抑制,中枢与外周免疫器官分子免疫调节功能障碍.7和21日龄AIV感染雏鸡均发病,但21日龄感染雏鸡上述指标的下降时间较7日龄感染雏鸡短且相对滞后,死亡率也较低,表明21日龄雏鸡免疫能力较强,具有一定的抗AIV感染能力.  相似文献   

17.
Variations of B lymphocytes bearing surface immunoglobulin (SIg) M [SIg(M)] and G [SIg(G)] were studied in the spleen and peripheral blood of chickens infected with infectious bursal disease virus (IBDV). The proportion of SIg-bearing B lymphocytes and SIg(M)- and SIg(G)-bearing B cells in chickens infected at one day of age decreased from 1 week postinfection (p.i.) onward and was significantly lower at 8 weeks p.i. In chickens infected at 4 weeks, the percentage of SIg-bearing B cells decreased severely during the first 2 weeks p.i. The decrease of SIg(M)-bearing B cells preceded that of SIg (G)-bearing B cells: the lowest percentage of SIg(M)-bearing B cells has observed 2 to 3 days p.i., and that of SIg(G)-bearing B cells was seen 4 days p.i. The results suggest that SIg(M)-bearing B cells are the major target for IBDV infection.  相似文献   

18.
为了探讨H9亚型禽流感病毒对MDCK细胞增殖及其培养基过氧化氢含量的影响,将不同剂量的H9亚型禽流感病毒接种MDCK细胞单层,吸附1.5h后弃去再加入新的DMEM维持液,每隔12h取上清液测定HA滴度、乳酸脱氢酶(LDH)活力以及过氧化氢(H2O2)含量。同时,本试验采用MTT法测定不同剂量病毒接种对MDCK细胞增殖的影响。结果表明,以10-3EID50、10-4EID50病毒剂量接种细胞后,病毒HA滴度分别在36h和48h达到滴度最大值(9log2)以及LHD活力的最大值,上清液中H2O2含量在48h时显著(P<0.05)高于空白对照组和低剂量病毒接种组;接种病毒后36h以内对MDCK细胞生长具有显著地(P<0.05)促进作用,之后会显著(P<0.05)抑制细胞的增殖。综上所述,H9亚型禽流感病毒能在前期促进MDCK细胞的增殖,随着病毒增殖对细胞损伤加大,LDH漏出量增加,促凋亡因子H2O2参与介导了这一过程。  相似文献   

19.
本试验旨在研究枯草芽孢杆菌(BS)048对雪山草鸡抗肠炎沙门氏菌(SE)感染能力的影响。选择240只体重(61.5±0.5)g的1日龄雪山草鸡公鸡(SE阴性),随机分为4组,每组设3个重复,每个重复20只鸡。对照组和对照感染组饲喂基础饲粮,BS组和BS感染组饲喂添加0.1%(质量分数)BS048的基础饲粮。对照感染组和BS感染组在5~7日龄时每天以1×108CFU的SE感染试验鸡只,试验期14 d。测定BS048对正常和SE感染雪山草鸡盲肠黏膜、肝脏、肾脏SE载菌量,血清免疫球蛋白(Ig)和回肠分泌型免疫球蛋白A(s Ig A)含量,空肠黏膜碱性磷酸酶(ALP)、髓过氧化物酶(MPO)、总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性与总抗氧化能力(T-AOC)以及丙二醛(MDA)含量的影响。结果表明:1)与对照组相比,BS组显著提高了雪山草鸡8、10、14日龄回肠s Ig A含量(P0.05),显著提高了10、14日龄空肠黏膜ALP活性(P0.05),极显著提高了10、14日龄的空肠黏膜T-AOC及T-SOD、GSH-Px活性(P0.01),显著降低了8、14日龄的空肠黏膜MDA含量(P0.05)。2)与对照感染组相比,BS感染组极显著减少了SE感染雪山草鸡盲肠黏膜、肝脏和肾脏SE载菌量(P0.01),显著提高了10、14日龄的血清Ig A、Ig G、Ig M及8、10、14日龄的回肠s Ig A含量(P0.05),显著提高了8、10、14日龄的空肠黏膜ALP活性P0.05),极显著降低了8、10、14日龄的空肠黏膜MPO活性(P0.01),显著或极显著提高了8、10、14日龄的空肠黏膜T-AOC及T-SOD、GSH-Px活性(P0.05或P0.01),显著或极显著降低了8、10、14日龄的空肠黏膜MDA含量(P0.05或P0.01)。由此可见,BS048能够增强雪山草鸡的抗SE感染能力。  相似文献   

20.
To study the individual and combined effects of fumonisin B1 (FB1) toxicity and Salmonella serotype Gallinarum infection, Japanese quail (Coturnix coturnix japonica) were fed Fusarium moniliforme culture material (2.5%), 150 mg FB1/kg ration, and were subsequently challenged orally with Salmonella Gallinarum organisms (2 x 10(4) colony-forming units) at 21 days of age. The chicks were fed culture material containing FB1 from day 5 till the end of the experiment. After being infected with Salmonella Gallinarum, observations were made 1, 2, 3, 5, 7, 10, 14, and 21 days postinfection. The clinical signs of diarrhea with bloody discharges were more pronounced in the Salmonella-infected birds on the FB1 diet. Mortality caused by Salmonella Gallinarum increased by 12% in the presence of FB1. Mean body weights in both the Salmonella-infected and FB1-fed groups were significantly lower than those of the controls at almost all intervals. Mean values of hemoglobin, packed cell volume, and total erythrocyte count were slightly higher in birds fed FB1 but were lower in the Salmonella Gallinarum groups fed FB1 and plain chick mash. Anemia was evident, between 5 and 10 days postinfection, in quail chicks infected with Salmonella Gallinarum alone. Total leukocyte counts were higher in Salmonella-infected and FB1-fed groups because of an increase in the number of heterophils and lymphocytes. However, the increase in lymphocyte response to infection was lower by 4.27%-30.09% between 3 and 21 days postinfection in the FB1-fed chicks compared with chicks infected with Salmonella Gallinarum. Alanine transaminase and total serum protein were slightly higher in both the infected and FB1-fed groups. This study revealed that the continuous presence of fumonisins in the diets of quail chicks might increase the susceptibility to or the severity of Salmonella Gallinarum infection.  相似文献   

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