Effects of Vagal and Sympathetic Nerves on Transmembrane Potential of Cardiac Ventricular Cells of Toad

The effects of vagal and sympathetic nerves on the transmembranepotentials of cardiac cells of toad were observed by means of microelectrodetechnique.The vagal nerve was stimulated there would be an increase in restingpotential and acceleration in repolarization of action potential(AP).However,ifatropine was used before stimulation the above-mentioned phenomena woulddisappear.When the sympathetic nerve was stimulated the AP amplitudeincreased,but resting potential(RP)remained the same.The increase of APresulted from the increases of overshoot.When the sympathetic nerve wasstimulated although the heart rate increased and the duration of AP wasshortened,the plateau phase of AP was prolonged.These results suggest that theeffects of vagal and sympathetic nerves on the transmembrane potential of cardiacventricular cells are coordinated and the normal characteritics of transmembranepotential are maintained by both the vagal and sympathetic nerves.     

Effect of electric and chemical stimulation of the raphe obscurus on phrenic nerve activity in the cat

The effect of electrical and chemical (l-glutamate) stimulation of the raphe obscurus on phrenic nerve activity was examined in the cat. Phrenic nerve activity was recorded from a C5 nerve root in anesthetized, paralyzed and artificially ventilated cats. Neural discharge was quantitated by integrating the phrenic nerve activity. The respiratory frequency was determined from the integrated nerve signal. Focal electrical stimulation (18–144 μA; 5–40 Hz; 100 μs pulse duration) resulted in significant (P < 0.05) increases in both integrated phrenic nerve (IPN) amplitude and respiratory frequency. These changes were dependent upon current intensity and frequency of stimulation. The largest increases in IPN amplitude and respiratory frequency were47 ± 17%and146 ± 8%, respectively. To insure that the changes in integrated phrenic nerve activity (IPNA) were the result of stimulation of cell bodies and not axons of passage,l-glutamate (100, 200 nmol) was microinjected (100 nl) into the raphe obscurus. Significant (P < 0.05) dose-related changes occurred in integrated phrenic nerve amplitude with an increase of44 ± 13% at 100 nmol and80 ± 13% at 200 nmoll-glutamate. No significant increase in respiratory frequency was observed withl-glutamate microinjection. The results suggest that the raphe obscurus may be involved in respiratory control.     

Arthroscopic treatment of elbowarthritis in athletes

Arthroscopy has a valuable role in the treatment of elbow arthritis in the athletic population. General arthroscopicdebridement techniques used in the treatment of arthritis in other joints are quite valuable. Arthroscopic modifications of open techniques unique to the elbow, such as ulnohumeral arthroplasty, also are useful. As in other joints, the benefits of arthroscopic treatment of elbow arthritis may be temporary. Proper patient selection and attention to technical detail are critical in this population.     

Tenotomy prevents the functional improvement of a muscle reinnervated with a chronically severed nerve

During the early stages of nerve implantation, we followed the dynamic properties of the lateral gastrocnemius muscle of the rat, reinnervated with an acutely or chronically severed peroneal nerve. The aim of this study was to ascertain whether (1) the better functional recovery of a muscle reinnervated by a chronically severed foreign nerve is present from the onset of reinnervation, and (2) whether such functional improvement is due to the conditioning lesion effect. Our results indicate that better functional recovery is already apparent one week after nerve implantation, and it is due to the conditioning lesion effect, since tenotomy prevents such improvement. The tenotomy effect underlines the fact that some environmental factors concerning the target tissue, and not only the predegenerated nerve, are involved in the conditioning effect. © 1995 Wiley-Liss, Inc.     

神经生长因子治疗颅脑损伤52例

本文报告用水囊引产胎儿脑黑质制备的神经生长因子(NGF)治疗52例颅脑损伤的临床观察结果:显效率91%。有效率100%,轻、中型患者疗效明显,显效率100%。其中头昏头痛,语言障碍,精神异常,大小便失禁,肢体功能障碍都有明显疗效。而且对儿童和病程短者效果更佳。认为治疗机理可能是 NGF 能预防神经元坏死,促进神经元及其纤维增生有关。结果表明,NGF 在治疗脑外伤及其后遗症中疗效确切,在颅外伤及其后遗症中可广为应用。     

Peripheral blood CD3 and CD4 T-lymphocyte reduction correlates with severity of liver cirrhosis

Summary Immunological disturbances with impairment of immune function and a higher incidence of lymphoproliferative disorders and other malignancies have been described in liver cirrhosis patients. To investigate the pathogenetic mechanism(s) involved in such associated we looked for a possible imbalance in peripheral blood T-lymphocyte subpopulations in patients with liver cirrhosis of differing severity. Immunophenotyping and counts of peripheral blood T-lymphocyte subpopulations were carried out using monoclonal antibodies conjugated with different fluorochromes in 31 consecutive cirrhotic patients and 23 matched healthy volunteers. Univariate and multivariate analyses of lymphocyte phenotype counts were performed and odds ratios were computed. Statistically significant associations, according to both univariate and multivariate analyses, were found between case/control status and mean CD3 and CD4 T-lymphocyte counts (P<0.0001). A strong correlation was found between the Pugh’s index and CD3 and CD4 lymphocyte counts, with a clear reduction of these phenotypes with increasing liver cirrhosis. Median CD3 and CD4 values were 2,283 and 1,329/μl respectively among controls and 896, 801, and 492/μl and 515, 514, and 307/μl, respectively in categories A, B, and C of Pugh’s classification. Very high odds ratios were found using the median values of CD3 and CD4 as a threshold. There was a statistically significant decrease for each of the T-cell phenotypes studied (CD2, CD3, CD4, CD8, CD16, CD19, CD20, CD56, CD57) between patients and controls (P<0.0001). The progressive and severity-related decrease in mean peripheral blood CD3 and CD4 counts in liver cirrhosis suggests a progressive impairment of protective immune function and may be a factor facilitating malignancy in cirrhotic patients.     

Peripheral clonal deletion of antiviral memory CD8+ T cells

Antiviral cytotoxic memory CD8⁺ T cells adoptively transferred to mice which are persistently infected with lymphocytic choriomeningitis virus WE or DOCILE initially proliferated extensively; they either caused the death of the recipient or, alternatively, disappeared within a few days. Apparently, the complete and coordinated induction and stimulation by widely distributed viral antigen caused these memory T cells to die before virus had been eliminated from the host. Thus memory T cells are as susceptible to peripheral exhaustion/deletion as unprimed T cells. These results indicate possible limitations of exclusively CD8⁺ T cell-mediated adoptive immunotherapy against viral infections or tumors.