Functional study of the rat cortical microcircuitry with voltage-sensitive dye imaging of neocortical slices

The computations performed within cortex are likely to be determined by its internal dynamics in addition to its pattern of afferent input. As a step toward characterizing these dynamics, we have imaged electrical activity in slices from rat primary visual cortex stained with the voltage-sensitive dye di-4-ANEPPS. In response to electrical stimulation two fluorescence signals of similar maximum amplitude are elicited, (i) A fast signal that peaks in a few milliseconds, is dependent on membrane voltage, and has a significant presynaptic component. This signal can be used to image electrical activity ratiometrically. (ii) A slow signal that peaks a few seconds after stimulation, does not reflect voltage changes, and may originate from changes in scattering properties of the slice and from interactions of the dye with the cells. The spatial pattern of fast signals obtained in response to focal stimulation of coronal slices is consistent with known interlaminar projection patterns. In tangential slices, imaging of fast signals reveals clustered horizontal responses. Finally, imaging of fast signals during epileptiform activation of the disinhibited circuit reveals propagating responses, without evidence for modular activation.     

Drug interactions with the nonsedating antihistamines

The nonsedating antihistamines are frequently prescribed agents. Well-documented drug-drug interactions with two of these agents, terfenadine and astemizole, may result in serious adverse effects, including death, when they are prescribed along with macrolide antibiotics and/or the antifungal agents itraconazole or ketoconazole. Fexofenadine and loratadine appear to be the least likely nonsedating antihistamines to interact with other medications and to result in a life-threatening interaction. This article reviews the known drug-drug interactions involving nonsedating antihistamines and provides a basis from which the clinician can predict potential interactions.     

(D)-penicillamine increases hepatic oxalate production resulting in hyperoxaluria

PURPOSE: To determine whether (D)-penicillamine is effective in reducing hepatic oxalate production and urinary oxalate excretion. MATERIALS AND METHODS: (D)-Penicillamine was administered orally to rats to determine its effect on urinary oxalate excretion and used in isolated rat hepatocytes to investigate the effect of (D)-penicillamine on oxalate production from glycolate. Studies involving hepatic aminotransferases and hepatocytes isolated from (D)-penicillamine treated rats were used to clarify the discrepancy between the in vitro and in vivo results. RESULTS: In hepatocytes (D)-penicillamine lead to a significant reduction in oxalate production from glycolate. In vivo however. (D)-penicillamine led to a significant increase in urinary oxalate excretion and a decrease in plasma aminotransferase activity. Hepatic aminotransferases are involved in diverting oxalate precursors from oxalate production. In vitro, (D)-penicillamine was shown to inhibit hepatic aminotransferases. Hepatocytes isolated from (D)-penicillamine-treated rats produced significantly more oxalate than controls. CONCLUSIONS: These results indicate that (D)-penicillamine increases hepatic oxalate production and urinary oxalate excretion. (D)-penicillamine therefore has no therapeutic potential for reducing endogenous oxalate production and urinary oxalate excretion. Moreover, in conditions such as Wilson's Disease which is often associated with hypercalcuria, its use may be contraindicated.     

Improved osseointeraction of calcium phosphate-coated external fixation pins. Studies in calves

The analysis of health state of drivers sent for an extra health examination for the estimation of driving capability for the driving of motor vehicle in alcoholic state was presented. The study included 380 drivers who were found driving drunk by traffic police (studied group) and 180 drivers of control group sent for an extra health examination for some other reason. The disorders in psychomotor sphere were noticed in the drivers of studied group and it was determined that they had caused significantly larger number of traffic accidents in last five-year period compared to the drivers of control group. The alcohol consumption in driving population represents significant medical, social, economic and traffic problem. The control of driver's alcoholism, the sending of alcoholic drivers to an extra health examination for the repeated estimation of driving capability and including in therapeutic and health-educational program can present significant measure of the primary prevention of road traffic traumatism which is on the constant increase.