Biomedical subjects

B Z Shi

Publications and source records attributed to B Z Shi.

8 recordsLinked to original sources

PubMed2001

[Protective effects of scopolamine on rabbits with acute brain injury].

OBJECTIVE: To study the protective effects of scopolamine (Sco) (a muscarinic receptor antagonist) on rabbits with acute brain injury, and preliminarily explore the roles of acetylcholine (ACh) in the early pathologic changes of traumatic brain injury(TBI). METHODS: The model of acute brain injury was established by a free-falling device, and the rabbits received Sco intraperitoneally at 5 minutes and 2 hours after brain injury respectively. Transcranial Doppler (TCD) was used to monitor cerebral blood flow velocity (CBV) and pulsatility index (PI) of middle cerebral artery (MCA). The levels of Ca2+, the activities of superoxide dismutase (SOD), the contents of malondiadehyde (MDA) and Evans blue (EB) were measured, and the pathological changes were observed in brain tissue. RESULTS: This model consisted with the pathologic changes of accelerated brain injury. Sco reduced the levels of Ca2+, EB and MDA, increased the activities of SOD, and improved cerebral blood flow following brain injury. CONCLUSIONS: In the early stage of brain injury, ACh can cause neuron calcium overload, oxide free radical reaction, cerebral vasospasm, and increase blood-brain barry(BBB) permeability. Scopolamine, a muscarinic receptor antagonist, can improve these pathologic changes. As a result, Sco has protective effects on brain tissue injury.

Acetylcholine↗

PubMed1989

[Confidence factors-method for estimating the confidence limits of standardized population rate of indirect method].

The standardized rate of indirect method is widely used, but no method of interval estimation for its population rate has been reported. The authors have discussed the standard error of standardized rate of indirect method and suggested that a method using this standard error should be used to determine the confidence limits for the population rate. In this paper, the authors put forward another method (Confidence Factors-Method) which can be easily applied to determine the confidence limits. It gives approximately the same result with the method mentioned above.

Mathematics↗

PubMed1989

[Rank transformations--the connection between nonparametric and parametric statistics].

The purpose of this paper is to present the relationship between nonparametric and parametric analysis by means of rank transformation. It is shown that in case of large sample, the resulting statistics getting from Wilcoxon rank test, Kruskal-Wallis and Friedman rank test are equivalent to the ratio of the sum of squares for treatment divided by mean square for the total variability calculated by ranks in the manner of the analysis of variance. It is also suggested that this method can be extended to factorial design experiments, and a detail procedure is given.

Multivariate Analysis↗

PubMed1988