[A study on cervical reflex induced by click stimuli in cats].

UNLABELLED: The effects of click stimuli on the cervical muscle have been wildly studied, but no information is available on what reaction click stimuli elicit from the cervical cord. We studied the effects of click stimuli on the cervical cord in cats. PURPOSE: To determine the response of the cervical cord to click stimuli in cats. MATERIALS AND METHODS: Subjects were ten adult cats confirmed to have normal tympanic membranes. Cats were placed on artificial ventilation by tracheal incision. Auditory brainstem response (ABR) of both ears was measured to determine its threshold. Following the cervical incision, the dorsal vertebrae were removed, the cervical cord was exposed at C3 to C6, and bipolar needle electrodes were inserted. The reference electrode was attached to the forehead. Click stimuli were presented using 1-20 Hz clicks. RESULTS: Responses peaking at 4.89-5.10 ms were induced by click stimuli of 105 dBSPL (1 Hz) at C3. Latencies tended to be prolonged with decreasing sound pressure. No response was confirmed at of C4 to C6. The responses to clicks of 20 Hz or more disappeared when 100 responses were summed. After the experiment, we confirmed that accessory nerves showed a response to electrical stimuli applied by bipolar needle electrodes. The cervical cord was removed to make sure that the electrode had been passed into the spinal nucleus of the accessory nerve. DISCUSSION: Spinal nuclei of accessory nerves exist at C3 to C5 of the cervical cord, and are associated with the movement of the sternocleidomastoid muscle at C3 in particular. Click stimuli are reported to affect the sternocleidomastoid muscle. The results of our study appear to reflect the response of the spinal nucleus of the accessory nerve to click stimuli. The fact that responses to clicks of 20 Hz or more disappeared when 100 responses were summed suggests that the response was induced via a pathway other than the auditory pathway.

Assessment of the biological malignancy of hepatocellular carcinoma: relationship to clinicopathological factors and prognosis.

It is difficult to determine the prognosis of patients with hepatocellular carcinoma (HCC). Assessment of the clinicopathological and biological malignancy of HCC may help in determining treatment strategies and predicting outcome. The tumor DNA content, p53 protein expression, proliferating cell nuclear antigen labeling index, and argyrophilic proteins of nuclear organizer regions were used as markers of biological malignancy. A correlation between these biological parameters and clinicopathological factors was sought. DNA aneuploidy was observed in 31 of 80 tumors (38.8%). Aneuploidy increased as differentiation decreased. The overall survival rate of patients with aneuploid tumors was significantly poorer than that of patients with diploid tumors. p53 overexpression was observed in 18 of 80 tumors (22.5%). The incidence of p53 positivity increased significantly with increasing tumor size and poorer differentiation. The overall survival rate of p53-positive patients was significantly worse than that of p53-negative patients. The proliferating cell nuclear antigen labeling index and the mean number of argyrophilic proteins of nuclear organizer regions were higher in more poorly differentiated lesions. We conclude that DNA ploidy and p53 expression are useful prognostic indicators in HCC. Cell proliferation increases as HCC progresses. With progression, tumors tend to become more poorly differentiated.

[The correlation between the MICs deduced from Showa disk method and the MICs determined by micro-dilution method].

Disc diffusion technique is useful to routine drug susceptibility testing for bacteria in clinical laboratories because of the advantages on simplicity and cost. Kirby-Bauer (KB) method recommended by NCCLS is using widely as a standard method of disk diffusion test, and simply categorize microorganisms as being susceptible, moderately susceptible, intermediate or resistant to different antimicrobial agents by the use of break point. In the determination of breakpoints, the relationship between MICs and clinical results and pharmacokinetics parameters (Cmax, T1/2 and AUC) are significantly considered. However, there are variance of pharmacokinetics among a race, moreover, breakpoint is not yet established in Japan. In report to doctor from clinical laboratory, the MIC might be better than that by breakpoint since there are such problems of breakpoint. Showa disk was developed as mono-disk method being able to deduce MIC from the linear regression between MIC and zone diameter. Therefore, it is thought that Showa disk is one of valuable methods for the routine drug susceptibility testing for bacteria in Japan. There is one problem, which is that MIC deduced by Showa disk is based on the relationship with agar dilution method although the determination method of MIC is going to turn into micro-dilution method, so we compared the MICs deduced from zone diameter of Showa disk method with the MICs determined by broth micro-dilution method by using a challenge set of 110 gram-positive and gram-negative bacteria for 7 antimicrobial agents. The total agreement of MIC within 1-log2 dilution difference was 77% and the correlation coefficient was 0.929. As results, a good relationship was obtained except the results of tetracycline and ofloxacin for beta-lactamase non-producing H. influenzae, and ceftizoxime for E. coli, and K. pneumoniae.