Effect of glucocorticoids on cows suspected of subclinical infection with M. paratuberculosis

Summary

Glucocorticoids were administered to 10 heifers suspected of subclinical infection with Mycobacterium paratuberculosis. Three animals remained untreated.

M. paratuberculosis was isolated from the internal organs of 2 animals after this treatment but not from any of the control group. Delayed type hypersensitivity and lymphocyte reactivity towards Johnin and purified protein derivates of M. avium and M. bovis were depressed. A sharp increase in total leucocyte count, due loan increase in neutrophil numbers, occurred. In the three untreated animals these parameters did not change during the experiment.

A decrease of specific immunological reactivity towards M. paratuberculosis occurred, but not to such an extent that clinical disease developed.     

Effect of electroacupuncture on microglia phenotype in injured abducens nerve

AIM: To investigate the effect of electroacupuncture treatment on microglia phenotype in Beagle dogs with abducens nerve injury. METHODS: Healthy adult Beagle dogs were randomly divided into 4 groups:normal control group, sham operation group, injury group and electroacupuncture treatment group, with 5 dogs in each group. In sham operation group, only the isolated nerves were exposed. In injury group, the dogs were restrained when electroacupuncture was performed in electroacupuncture treatment group. In electroacupuncture treatment group, electroacupuncture was performed on the base of dog nerve injury. The experiment was continued for 2 weeks. Western blot was used to detect the expression levels of M1 and M2 markers in the microglia. RESULTS: The expression of inducible nitric oxide synthase (iNOS) in injury group was significantly higher than that in control group (P<0.05). In electroacupuncture treatment group, the expression of iNOS was significantly lower than that in injury group (P<0.05). The expression of interleukin-1β (IL-1β) in injury group and electroacupuncture treatment group was higher than that in control group and that in electroacupuncture treatment group was significantly lower than that in injury group (P<0.05). The expression of arginase in injury group and electroacupuncture treatment group was higher than that in control group (P<0.05), and that in electroacupuncture treatment group was higher than that in injury group (P<0.05). Meanwhile, the expression of brain-derived neurotrophic factor (BDNF) in injury group and electroacupuncture treatment group was increased compared with control group (P<0.05). But the expression of BDNF in electroacupuncture treatment group was higher than that in injury group (P<0.05).CONCLUSION: After abducens nerve injury, electroacupuncture treatment reduces the expression levels of M1 marker proteins in microglia and increases the expression levels of M2 marker proteins.     

小美牛肝菌生物碱抑制运动神经系统原理

通过大鼠急性毒性试验、大鼠脊髓损伤运动功能试验和大鼠脊髓含水量试验,对小美牛肝菌生物碱抑制运动神经系统的原理进行研究。大鼠急性毒性试验结果表明,小美牛肝菌生物碱含有一定的毒性,对机体组织的运动神经系统有一定的影响;大鼠脊髓损伤运动功能试验结果表明,小美牛肝菌所含的生物碱物质能够促进大鼠脊髓损伤恢复,降低大鼠脊髓神经损伤;大鼠脊髓含水量试验结果表明,小美牛肝菌生物碱具有消炎抗氧化作用,能够降低过氧化物对神经细胞的损害。     

miR-21 inhibits apoptosis of Schwann cells following peripheral nerve injury

AIM: To explore the relationship and molecular mechanism between microRNA-21(miR-21) and Schwann cells (SC) following peripheral nerve injury. METHODS: The mRNA expression of miR-21 and phosphatase and tensin homologue deleted on chromosome ten (PTEN) in animal model were detected by real-time PCR. The over-expression of miR-21 and inhibition of miR-21 expression in the Schwann cells according to transfection of lentiviral vectors were performed, the nonspecific miRNA was used as a negative control (NC). The cell apoptosis was measured by flow cytometry. The mRNA expression of miR-21 and PTEN in the cells was detected by real-time PCR. The protein expression of PTEN and cleaved caspase-3 was determined by Western blot. RESULTS: The level of miR-21 was significantly higher and the mRNA level of PTEN was significantly lower in the model of nerve injury than those in control group. miR-21 over-expression decreased the number of apoptotic Schwann cells compared with NC-SC. The mRNA expression of PTEN was down-regulated by over-expression of miR-21. The protein expression of PTEN and cleaved caspase-3 was down-regulated by over-expression of miR-21(P<0.05). CONCLUSION: miR-21 may play an important role in the peripheral nerve injury through inhibiting apoptosis of Schwann cells by down-regulating the expression of PTEN.     

T2‐WEIGHTED MAGNETIC RESONANCE IMAGING MEASUREMENTS OF OPTIC NERVE SHEATH DIAMETER IN DOGS WITH AND WITHOUT PRESUMED INTRACRANIAL HYPERTENSION

Intracranial hypertension is a cause of cerebral ischemia and neurologic deficits in dogs. Goals of this retrospective study were to test interobserver agreement for MRI measurements of optic nerve sheath diameter and associations between optic nerve sheath diameter, signalment data, and presumed intracranial hypertension status in a cohort of dogs. A veterinary radiologist interpreted scans of 100 dogs and dogs were assigned to groups based on presence or absence of at least two MRI characteristics of presumed intracranial hypertension. Two observers who were unaware of group status independently measured optic nerve diameter from transverse T2‐weighted sequences. Mean optic nerve sheath diameter for all dogs was 3 mm (1–4 mm). The mean difference between observers was 0.3 mm (limits of agreement, ?0.4 and 1.0 mm). There was no correlation between optic nerve sheath diameter and age for either observer (r = ?0.06 to 0.00) but a moderate positive correlation was observed between optic nerve sheath diameter and body weight for both observers (r = 0.70–0.76). The 22 dogs with presumed intracranial hypertension weighed less than the 78 dogs without (P = 0.02) and were more often female (P = 0.04). Dogs with presumed intracranial hypertension had a larger ratio of optic nerve sheath diameter to body weight for each observer‐side pair (P = 0.01–0.04) than dogs without. Findings indicated that the ratio of MRI optic nerve sheath diameter relative to body weight may be a repeatable predictor of intracranial hypertension in dogs.     

鹅颈动脉颈神经的解剖学观察和溃变法研究

鹅颈动脉颈神经分布到颈动脉上的神经丛有两种情况：有神经节与无神经节。溃变结果表明在颈前神经节和颈交感干神经节上都出现有溃变细胞，说明颈动脉神经中至少含有由颈前神经节的节后纤维和经由颈交感干神经节的节前与节后纤维。颈动脉颈神经在第１５～１６颈椎段从两侧颈长肌缝中走出分布于皮下。     

The use of a nerve stimulation test to confirm sacrococcygeal epidural needle placement in cats

ObjectiveTo determine if a nerve stimulation test (NST) could act as a monitoring technique to confirm sacrococcygeal epidural needle placement in cats.Study designProspective experimental trial in a clinical setting.AnimalsTwenty-four adult cats, scheduled for a therapeutic procedure where epidural anesthesia was indicated.MethodsUnder general anesthesia, an insulated needle was inserted through the S₃-Cd₁ intervertebral space guided by the application of a fixed electrical current (0.7 mA) until a motor response was obtained. The NST was considered positive when the epidural nerve stimulation produced a motor response of the muscles of the tail, whereas it was considered negative when no motor response was evoked. In the NST positive cases, 0.3 mL kg⁻¹ of 0.5% bupivacaine was administrated before needle withdrawal. Ten minutes after injection, epidural blockade was confirmed by the loss of perineal (anal), and pelvic limbs reflexes (patellar and withdrawal).ResultsThe use of a fixed electrical stimulation current of 0.7 mA resulted in correct prediction of sacrococcygeal epidural injection, corroborated by post bupivacaine loss of perineal and pelvic limb reflexes, in 95.8% of the cases.Conclusion and clinical relevanceThis study demonstrates the feasibility of using, in a clinical setting, an electrical stimulation test as an objective and in real-time method to confirm sacrococcygeal epidural needle placement in cats.     

鸡脑桥内神经核团的形态学研究

试验利用3只白来杭鸡脑制成的冰冻切片，经Nissl法染色，光镜观察分布于脑桥内的神经核团位置、形态及细胞组成。结果表明：中央上核位于中脑内；三叉神经运动核划分为内侧亚核和外侧亚核；三叉神经感觉主核前极在三叉神经运动核前极近平面；上橄榄核为一单一圆形核团；桥外侧核划分为两个亚核；首次观察到鸡脑桥中存在面神经副核；尾侧线形核、桥吻侧网状核、桥尾侧网状核、展神经核、耳蜗神经核、前庭神经核群等核团与前人观点一致。     

磁场对固定化乳酸脱氨酶催化活性的影响

采用流通池光纤荧光光度法，对固定化乳酸脱氢酶（ＬＤＨ）在静磁场作用下的催化活性进行了探讨．发现在０．０８４～０．２３０Ｔ磁场作用下ＬＤＨ的催化活性明显降低，其降低值随磁场强度增强而增大，且与磁场作用的时间和ｐＨ值有关，而在２５～４０℃范围内，温度则无显著影响。