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1.
Early diagnosis of MAP infection is a pressing need to enable efficient intervention with the spread of MAP infection in herds. Hence, study of lymphocyte subsets and their expressed adhesion molecules could contribute in defining a distinct diagnostic marker (or markers) at the subclinical period of the infection that could in turn facilitate the development of effective diagnostic approach. In accordance with this objective, milk and blood samples were collected from two groups of cattle naturally infected with MAP and their corresponding negative controls. Group (C) comprised 3-4 year-old ELISA negative/PCR positive-cattle that were considered as subclinical seronegative low shedder group (early stage). Group (A) included 6-8 year-old ELISA positive-cattle, which were considered as a clinical seropositive group (late stage). Flow cytometry of B cells, CD8+, CD4+ and γδ cells and the adhesion molecules CD44+, CD62L, LFA-1 and LPAM-1 indicated increase in CD4+ and B cells levels, with higher levels in blood than milk of group A, and significant expression of CD44+ in blood and milk and LPAM-1 in blood only. The CD8+ cells count in milk was higher than blood in the late stage. The peculiar feature of the early stage (group C) was the high level of γδ cells in the blood and milk, with tendency to express high level of CD62L. Compelling evidence could support the assumption that the dominant γδ cells at early stage of MAP infection could be of CD8CD2−WC+1+ phenotype. γδ cells appear as promising markers in defining early changes of MAP infection due to their important role in priming innate and cell mediated immunity. Possible utilization of these peculiar changes in the γδ cells level in the early diagnosis of MAP infection should be the subject of further research.  相似文献   

2.
Toxocara canis is regarded as the main cause of human toxocarosis but the relative contribution of T. cati is probably underestimated; serological and other diagnostic methods used in most studies of this zoonotic disease do not distinguish between the two parasites. The definitive hosts for T. canis are caniidae. Pups generally have higher infection rates than adult animals and are a major source of eggs in the environment. Humans usually acquire T. canis infection by accidental ingestion of embryonated eggs or encapsulated larvae from the environment or contaminated food, such infections may lead to visceral larva migrans (VLM), ocular larva migrans (OLM) or covert toxocarosis (CT). Although a mixed Th1- and Th2-mediated immunological response, particularly with high levels of IgE and eosinophilia is observed, the underlying mechanisms of molecular and immunopathogenesis for the development of the symptomatic syndromes of VLM, OLM, or of asymptomatic CT are largely unclear. Studies have indicated that immunological defences against various infectious diseases may be highly influenced by complex interactions of environmental and host genetic factors e.g. MHC class I and II, also known as human leucocyte antigen (HLA). Toxocara spp. infections are associated with a polarized CD4+ Th2 response with high IgE levels and eosinophilia, mediated mainly by HLA class II molecules. Associations have been made between HLA class II and pathological severity and host genetic effects on exposure to infection. Recent research suggests Foxp3+ CD4+CD25+-expressing T regulatory (Treg) cells play a role in regulation of the immunopathology of granulomas in experimental toxocaral granulomatous hepatitis and in enhanced expression of TGF-β1, which is an important factor for the local survival and function of Treg observed during T. canis invasion in the mouse small intestine, liver, muscle, and brain. Since the potential susceptibility loci HLA class II molecules, are considered involved in the regulation of a Th2-dominant immunity which is highly controlled by Foxp3+ CD4+CD25+ Treg cells by stimulation through TGF-β1, which thus provides a beneficial environment to T. canis larvae but severe injuries to local organs. However, TGF-β1 variant Leu10Pro known to be involved in disease severity warrants further elucidation as this too may have a role in the severity of human toxocarosis. Exploration of TGF-β1 polymorphism, Foxp3+ CD4+CD25+ Treg cells, and MHC polymorphisms may allow insight into the contribution made by environmental and genetic factors in influencing disease syndrome type and severity in humans with toxocarosis.  相似文献   

3.
The effect of training on the potential for work in draught cattle was assessed by measuring the Na+,K+-ATPase in the muscle cell membrane and the elevation in the concentration of K+ in plasma during exercise. Biopsies of the semitendinosus muscle and venous blood samples were taken from the cattle used for draught work in Mozambique. No differences were found in the plasma ion or Na+,K+-ATPase concentrations in samples taken from Nguni, Africander and Angoni breeds. There were no significant differences in plasma ions (Na+, K+ and Cl–) or muscle Na+,K+-ATPase concentrations between the Angoni males and females, although the males showed an increase in Na+,K+-ATPase with age, while the females showed a decrease. The increase in males might be attributed to their higher level of activity in the herds than that of females. After a training period of 15 days, a significant increase in Na+,K+-ATPase concentration in semitendinosus muscle was found in Angoni cattle. In females, this was significant after 8 days of training (about 30%); in males after 15 days of training (about 16%). On day 15, there was a reduction in the elevation of plasma K+ during the 2 h of draught work, indicating an increased capacity of the Na+,K+ pumps to maintain the extracellular K+ concentration in working muscles and a possible delay in the moment of fatigue.  相似文献   

4.
抗菌肽[L6,K11]-IsCT抑菌性能及其稳定性研究   总被引：1，自引：1，他引：0  
IsCT最初是从蝎子中分离出的一种非细胞选择性线性抗菌肽,为了将其应用于动物饲料,需研究其对常见致病菌的抑制和杀灭作用。本试验采用微量稀释法和琼脂扩散法对ISCT衍生物[L6,K11]-IsCT的抗菌活性及其稳定性进行探索。结果显示,相对于金黄色葡萄球菌,[L6,K11]-IsCT对大肠杆菌具有更好的抑制作用,其对大肠杆菌的最小抑菌浓度为50 μg/mL。另外,该衍生物对高温表现出很好的稳定性,同时具有很好的酸碱耐受性和人工胃液耐受性。经121 ℃、0.12 MPa处理30 min,以及2.0≤pH≤11.0处理30 min或人工胃液2 h孵育处理后,依然能保持很好的抑菌活性。  相似文献   

5.

Background

The p21-activated kinase 1 (PAK1) is essential for mitosis and plays an important role in the regulation of microtubule assembly during oocyte meiotic maturation in mice; however, little is known about its role in porcine oocytes.

Result

Total p21-activated kinase 1 (PAK1) and phosphorylated PAK1 at Thr423 (PAK1Thr423) were consistently expressed in porcine oocytes from the germinal vesicle (GV) to the second metaphase (MII) stages, but phosphorylation of histone H3 at Ser10 (H3Ser10) was only expressed after the GV stage. Immunofluorescence analysis revealed that PAK1Thr423 and H3Ser10 colocalized on chromosomes after the GV stage. Blocking of endogenous PAK1Thr423 by injecting a specific antibody decreased the phosphorylation level of H3Ser10; however, it had no impact on chromatin condensation, meiotic progression, cleavage rate of blastomeres or the rate of blastocyst formation.

Conclusion

Phosphorylation of PAK1Thr423 is a spontaneous activation process and the activated PAK1Thr423 can promote the phosphorylation of H3Ser10; however, this pathway is not required for meiotic maturation of porcine oocytes or early embryonic development.  相似文献   

6.
Using whole body autoradiography and impulse counting technique, distribution of intramuscularly administered 14C-DL-hydroxyproline and 14C-L-proline in newborn piglets was compared. The main excretion route of hydroxy-proline was via the kidneys. Hydroxyproline or its metabolic products were excreted at quite another rate by the liver than was proline. Skeletal muscles and myocardium showed a lowered ratio of proline to hydroxyproline. A difference in favour of hydroxyproline in passing the blood-brain barrier was shown. Contrary to proline hydroxyproline yielded a low 14C-level in the skeletal tissues. The possibilities of an incomplete hydroxylation of proline as an aetiological factor in the origin of skeletal disorders are discussed.  相似文献   

7.
Mammalian oocyte maturation and early embryo development processes are Ca2+-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca2+ and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca2+ was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca2+ was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca2+ was present throughout the blastomere. In PA embryos, Ca2+ was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca2+ in the SCNT embryos. However, Ca2+ was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca2+ showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca2+ location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.  相似文献   

8.
This study aimed to establish a standard dose and sample collection time for 13C phenylalanine and 13C-Dipeptide breath test in horses. To evaluate dose-dependent effects, healthy horses received 2.5 mg/kg, 5 mg/kg, and 10 mg/kg 13C phenylalanine dissolved in 1 ml/kg distilled water and 1.25 mg/kg, 2.5 mg/kg, and 5 mg/kg 13C dipeptide dissolved in 2 ml/ kg distilled water. Tmax was observed during the sample collection time. For 13C phenylalanine, the standard deviation of Cmax at 5 mg/kg was lower than that of 10 mg/kg. For 13C dipeptide, the standard deviation of Tmax was the lowest at 5 mg/kg. This study revealed that an optimal dose for breath tests with 13C phenylalanine and 13C dipeptide may be 5 mg/kg in horses.  相似文献   

9.
This study was carried out in order to estimate caecotrophe intake in growing rabbits by three existing procedures: caecotrophes collection after collar fitting, urinary purine derivatives (PD) excretion and microbial 15N-lysine incorporation. In a first experiment sixteen New Zealand White male rabbits were divided in three groups receiving the same diet, but supplemented with 15NH4Cl in the first group (T1: 6 rabbits). The second group (T2: 6 rabbits) was also fed the labelled diet but only during the last ten days of the fattening period when animals were fitted a neck collar to prevent caecotrophy. The third group (T3: 4 animals) received the basal diet and was used as control. In two additional trials the daily contribution to urinary excretion of endogenous purine compounds (469 ± 50.8 μmol/W0.75) and creatinine excretion (807 ± 127.6 μmol/W0.75) were determined. The highest estimation of microbial nitrogen recycling was obtained by the urinary PD method (0.79 ± 0.096 g/d), whereas caecotrophes collection and 15N-lysine incorporation methods showed similar values (0.49 ± 0.049 and 0.45 ± 0.015 g/d, respectively). Our results seem to indicate an overestimation of microbial nitrogen recycling in growing rabbits by PD methodology, while neck collar fitting procedure gave similar results, although more variable than microbial 15N-lysine incorporation.  相似文献   

10.

Background

Mycoplasma bovis is associated with pneumonia in calves characterized by the development of chronic caseonecrotic lesions with the agent persisting within the lesion. The purposes of this study were to characterize the morphology of lung lesions, examine the presence of M. bovis variable surface protein (Vsp) antigens and study the local immune responses in calves after infection with M. bovis strain 1067.

Methods

Lung tissue samples from eight calves euthanased three weeks after experimental infection with M. bovis were examined by bacteriology and pathology. Lung lesions were evaluated by immunohistochemical (IHC) staining for wide spectrum cytokeratin and for M. bovis Vsp antigens and pMB67 antigen. IHC identification and quantitative evaluation of CD4+ and CD8+ T lymphocytes and immunoglobulin (IgG1, IgG2, IgM, IgA)-containing plasma cells was performed. Additionally, expression of major histocompatibility complex class II (MHC class II) was studied by IHC.

Results

Suppurative pneumonic lesions were found in all calves. In two calves with caseonecrotic pneumonia, necrotic foci were surrounded by epithelial cells resembling bronchial or bronchiolar epithelium. In all calves, M. bovis Vsp antigens were constantly present in the cytoplasm of macrophages and were also present extracellularly at the periphery of necrotic foci. There was a considerable increase in numbers of IgG1- and IgG2-positive plasma cells among which IgG1-containing plasma cells clearly predominated. Statistical evaluation of the numbers of CD4+ and CD8+ T cells, however, did not reveal statistically significant differences between inoculated and control calves. In M. bovis infected calves, hyperplasia of bronchus-associated lymphoid tissue (BALT) was characterized by strong MHC class II expression of lymphoid cells, but only few of the macrophages demarcating the caseonecrotic foci were positive for MHC class II.

Conclusions

The results from this study show that infection of calves with M. bovis results in various lung lesions including caseonecrotic pneumonia originating from bronchioli and bronchi. There is long-term persistence of M. bovis as demonstrated by bacteriology and immunohistochemistry for M. bovis antigens, i.e. Vsp antigens and pMB67. The persistence of the pathogen and its ability to evade the specific immune response may in part result from local downregulation of antigen presenting mechanisms and an ineffective humoral immune response with prevalence of IgG1 antibodies that, compared to IgG2 antibodies, are poor opsonins.  相似文献   

11.
A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae. The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4+ T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by CD8/IFN-γ double positive cells. γδ T-cells were not expanded at any time point analysed. IFNγ+ T cells disappear 60 days after infection, suggesting that antigen specific IFNγ+ T cells, mainly detected in the early phase of the disease, could be useful to understand the role of cell-mediated immunity during M. agalactiae infection.  相似文献   

12.
The renal excretion of N4-acetyl sulphanilamide and N4-acetyl sulphadimidine was studied in 19 experiments with 6 goats during continuous intravenous administration of the 2 sulphonamide derivatives. Deacetylation of both compounds takes place to a small extent only. Further it is shown that both sulphonamide derivatives are bound to plasma proteins to a greater extent than sulphanilamide and sulphadimidine. The excretion of the N4-acetylated sulphonamides is compared with the renal excretion of creatinine. The non-protein-bound fraction of the 2 N4-acetylated sulphonamides is excreted by filtration and active tubular secretion. The renal clearances of the acetyl derivatives are higher than those of the parent compounds.  相似文献   

13.
Changes in electrophysiological properties, such as ion channel expression and activity, are closely related to arrhythmogenesis during heart failure (HF). However, a causative factor for the electrical remodeling in HF has not been determined. Periostin (POSTN), a matricellular protein, is increased in heart tissues of patients with HF. In the present study, we investigated whether a single injection of POSTN affects the electrophysiological properties in rat ventricles. After male Wistar rats were intravenously injected with recombinant rat POSTN (64 µg/kg, 24 hr), electrocardiogram (ECG) was recorded. Whole-cell patch clamp was performed to measure action potential (AP) and Na+ current (INa) in isolated ventricular myocytes. Protein expression of cardiac voltage-gated Na+ channel (NaV1.5) in isolated ventricles was examined by Western blotting. In ECG, POSTN-injection significantly increased RS height. POSTN-injection significantly delayed time to peak in AP and decreased INa in the isolated ventricular myocytes. POSTN-injection decreased NaV1.5 expression in the isolated ventricles. It was confirmed that POSTN (1 µg/ml, 24 hr) decreased INa and NaV1.5 protein expression in neonatal rat ventricular myocytes. This study for the first time demonstrated that a single injection of POSTN in rats decreased INa by suppressing NaV1.5 expression in the ventricular myocytes, which was accompanied by a prolongation of time to peak in AP and an increase of RS height in ECG.  相似文献   

14.
Changes in the proportion of peripheral blood T cell subsets after subcutaneous inoculation of cattle with Mycobacterium bovis Bacille Calmette-Guerin (BCG) were studied. Calves were injected with approximately 8 × 106 BCG bacillus and blood samples collected at weekly intervals for flow-cytometric analyses to determine the proportion of CD4+, CD8+ and γδ T cells. In addition, whole blood samples were stimulated in vitro with M. bovis purified protein derivative (PPD) and the secreted IFN-γ quantified by ELISA. Results showed cellular and cytokine changes which could be categorized into three phases. The first phase occurred within the first 2 weeks after vaccination involving an increase in proportion of WC1+ γδ T cells and a concomitant increase in the secretion of IFN-γ. These two responses peaked at 2 weeks and waned thereafter. The second phase involved an increase in the CD4/CD8 ratio as a result of an increase in the proportion of CD4+ T cells between 4 and 6 weeks. The third phase involved a decrease in the CD4/CD8 ratio due to an increase in the proportion of CD8+ T cells between 8 and 10 weeks. Surprisingly, the IFN-γ response was associated with changes in the γδ rather than the CD4+ or CD8+ T cells, suggesting that this cytokine was secreted by γδ-T cells. These results are consistent with the reported ability of γδ T cells to act rapidly and bridging the innate and classically adaptive immune responses.  相似文献   

15.
One hundred and ninety-two barrows (Duroc × Landrace × Yorkshire, initial weight 27.7 kg) were used to investigate the effects of cadmium in feed on the function of selected organs and meat colour of growing pigs. The pigs were randomly allocatted into four different treatments. Each treatment included three replications with 16 pigs per replicate. The animals were fed corn–soybean basal diet and supplemented with 0, 0.5, 5.0, 10.0 mg/kg cadmium (as CdCl2), respectively. The feeding trial ended when the average body weight of the pigs reach 90 kg. The results showed that, compared with controls, addition of 10 mg/kg cadmium to the diet resulted in significant elevations of relative weight of liver and spleen by 18.3% (p < 0.05) and 19.7% (p < 0.05) respectively, and of serum glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) activities by 17.8% (p < 0.05) and 27.4% (p < 0.05) respectively; and significant decreases of Na+/K+-ATPase activity in the liver by 24.6% (p < 0.05), the redness of longissimus dorsi by 26.6% (p < 0.05) and 24.9% (p < 0.05) at 0.75 h and 16 h post mortem, respectively, and of the myoglobin content of longissimus dorsi by 19.4% (p < 0.05). No changes were found in these indices above when the pigs were fed the diet supplied with 0.5 or 5 mg/kg cadmium (p > 0.05), nor in renal functions among cadmium-treatment treatments (p > 0.05) as indicated is the activities of urinary N-acetyl-β-d-glucosaminidase (NAG) and alkaline phosphatase (ALP) and the content of urinary protein. The study indicated the adverse effects of 10 mg/kg cadmium in feed on liver functions and meat colour of growing pigs.  相似文献   

16.
The Ay allele at the agouti locus causes obesity and promotes linear growth in mice. However, body weight gain stops between 16 and 17 weeks after birth, and then, body weight decreases gradually in DDD.Cg-Ay male mice. Body weight loss is a consequence of diabetes mellitus, which is genetically controlled mainly by a quantitative trait locus (QTL) on chromosome 4. This study aimed to further characterize diabetes mellitus and body weight loss in DDD.Cg-Ay males. The number of β-cells was markedly reduced, and plasma insulin levels were very low in the DDD.Cg-Ay males. Using a backcross progeny of DDD × (B6 × DDD.Cg-Ay) F1-Ay, we identified one significant QTL for plasma insulin levels on distal chromosome 4, which was coincidental with QTL for hyperglycemia and lower body weight. The DDD allele was associated with decreased plasma insulin levels. When the DDD.Cg-Ay males were housed under three different housing conditions [group housing (4 or 5 DDD.Cg-Ay and DDD males), individual housing (single DDD.Cg-Ay male) and single male housing with females (single DDD.Cg-Ay male with DDD.Cg-Ay or DDD females)], diabetes mellitus and body weight loss were most severely expressed in individually housed mice. Thus, the severity of diabetes and body weight loss in the DDD.Cg-Ay males was strongly influenced by the housing conditions. These results demonstrate that both genetic and nongenetic environmental factors are involved in the development of diabetes mellitus and body weight loss in the DDD.Cg-Ay males.  相似文献   

17.
In order to investigate the effects of SKF96365 (SKF), which is a non-selective cationic channel blocker, on K+ channel currents, we recorded currents through ATP sensitive K+ (IKATP), voltage-gated K+ (IKv) and Ca2+ activated K+ channels (IBK) in the absence and presence of SKF in single small intestinal myocytes of mice with patch-clamp techniques. SKF (10 µM) reversibly abolished IKATP that was induced by cromakalim (10 µM), which is a selective ATP sensitive K+ channel opener. These inhibitory effects were induced in a concentration-dependent and voltage-independent manner. The 50% inhibitory concentration (IC50) was 0.85 µM, which was obviously lower than that reported for the muscarinic cationic current. In addition, SKF (1 µM ≈ the IC50 value in IKATP suppression) reversibly inhibited the IKv that was induced by repetitive depolarizing pulses from −80 to 20 mV. However, the extent of the inhibitory effects was only ~30%. In contrast, SKF (1 µM) had no significant effects on spontaneous transient IBK and caffeine-induced IBK. These results indicated that SKF inhibited ATP sensitive K+ channels and voltage-gated K+ channels, with the ATP sensitive K+ channels being more sensitive than the voltage-gated K+ channels. These inhibitory effects on K+ channels should be considered when SKF is used as a cationic channel blocker.  相似文献   

18.
RNA m6A甲基化修饰是发生在RNA腺嘌呤（A）第6位N原子上的一种转录后修饰方式。它是由甲基转移酶和去甲基酶以及识别蛋白所催化的一种动态可逆的修饰方式,具有重要的调控功能。本文综述了m6A甲基化的发现、相关酶的作用以及在生命过程中的重要功能,以期对未来研究m6A在牛的遗传育种方面的调控作用提供重要的理论支持。  相似文献   

19.
T cells are the dominant lymphocytes in the endometrium and are considered to play a crucial role in implantation and in the maintenance of gestation through cytokine production and immune regulation. The mechanisms underlying immunoregulation at the feto-maternal interface are still obscure for this complex system. Understanding the role of T cells is a key factor in understanding the endometrial immune system. In this study, the distribution of endometrial CD3+ T cells in bovines was examined by immunohistochemical analysis. The estrous cycle and gestation was divided into 4 stages, and the number of CD3+-positive T cells was counted in each stage. CD3+ cells were found in the endometrium in significant numbers throughout the estrous cycle and were mostly located in the subepithelial area. The number of CD3+ cells significantly increased in the early and mid-luteal phases but decreased after implantation with the progression of gestation. No T cells were found in the placentome or specifically in the tissues near the fetus, including the trophoblastic area. In addition, very few T cells were found in stromal regions close to the myometrium of the endometrium. These findings suggest that downregulation of bovine endometrial CD3+ T-cell functions is closely related to the successful maintenance of gestation in a spatiotemporal manner.  相似文献   

20.
The purpose of this study was to determine whether the Ca2+ signaling pathway is involved in the ability of osteoprotegerin (OPG) to inhibit osteoclast differentiation and maturation. RAW264.7 cells were incubated with macrophage colony-stimulating factor (M-CSF) + receptor activator of nuclear factor-κB ligand (RANKL) to stimulate osteoclastogenesis and then treated with different concentrations of OPG, an inhibitor of osteoclast differentiation. The intracellular Ca2+ concentration [Ca2+]i and phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the different treatment groups were measured by flow cytometry and Western blotting, respectively. The results confirmed that M-CSF + RANKL significantly increased [Ca2+]i and CaMKII phosphorylation in osteoclasts (p < 0.01), and that these effects were subsequently decreased by OPG treatment. Exposure to specific inhibitors of the Ca2+ signaling pathway revealed that these changes varied between the different OPG treatment groups. Findings from the present study indicated that the Ca2+ signaling pathway is involved in both the regulation of osteoclastogenesis as well as inhibition of osteoclast differentiation and activation by OPG.  相似文献   

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