Improvement of visualization in computed tomographic colonography after mechanic air insufflation.

OBJECTIVE: Our aim was to develop an insufflation system for CT colonography enabling even and quick air inflation as well as pressure control and optional emergency decompression. PATIENTS AND METHODS: A modified air insufflation system for CT colonography, consisting of an electric air pump, manometer, safety valve, and a balloon tip is presented. Thirty one patients underwent CT colonography from August to December, 2004. RESULTS: Optimal distension was achieved in 30 patients; the distension was incomplete (partial) only in one case. The insufflation was performed within 60 seconds in 28 of the cases, in 2 patients--within 180 seconds and in one patient--after 180 seconds. CONCLUSIONS: The presented insufflation system allows optimization of CT colonography technique, reduces the risk of adverse events during examination and improves the precision of the method.

Effect of tacrine on cytosolic Ca2+ level and calmodulin in gastric muscle tissues of rat.

INTRODUCTION: Tacrine is an acetylcholinesterase inhibitor. It has an indirect cholinomimetic effect inducing contractions of the gastric smooth muscles. The contractions are related to the effect of the accumulated acetylcholine in tissues on the respective choline receptors. There is a well defined direct correlation between tacrine concentrations and the inhibition of cholinesterase activity. That suggest simultaneous increase of the strength of tacrine-induced contractions. Instead, at concentrations above 1 x 10(-5) mol/l, tacrine causes permanent relaxation with yet unknown causing mechanism. AIM: The aim of this study was to investigate if tacrine induces reduction of calcium ions through chelation and/or inhibits directly calmodulin's participation in the contractile processes, thus causing smooth muscle relaxation which is not characteristic of a typical acetylcholinesterase blocker. METHODS: The contractile activity of smooth muscle preparations was measured isometrically with a Microtechna (Czech Republic) amplifier and recorded by a Linseis (Germany) recorder. The absorption electron spectrum of tacrine (1 x 10(-4) mol/l) was determined with a Cary 1 (Varian, Australia) spectrophotometer. The concentration of ionized CaCa2+ was measured with the ISE-block of a clinical-chemical analyzer Konelab 60 (Finland). RESULTS: The presence of Ca2+ (10(-2) mol/l) does not alter tacrine characteristic absorption spectrum at pH values corresponding to the SM cell cytosolic pH. The presence of 1 x 10(-4) mol/l tacrine does not affect Ca2+ concentration in the Krebs solution (pH = 7.4). In the presence of trifluoperazine (a calmodulin blocker) 1 x 10(-4) mol/l tacrine causes relaxation which is commensurable with that in the controls. CONCLUSIONS: Tacrine-induced smooth muscle relaxation is not a result of the reduction of the effective Ca2+ concentrations as a result of chelation between tacrine and Ca2+ and it is not related to the tacrine effects on calmodulin.

Influence of thiamine on the behavioral sensitivity to ethanol.

Changes in sensitivity to ethanol's rate-decreasing effects on operant performance were examined in control rats and cohorts that received diet-induced or diet+pyrithiamine-induced thiamine deficiency. Seven groups of male Sprague-Dawley rats (12 rats/group) were trained in a 5-cycle lever-press operant task under a fixed-ratio 30 schedule of food reinforcement. Once trained to maintain consistent operant performance across all 5 cycles, each rat was tested with various doses of ethanol injected at the beginning of each time-out cycle. Each group of rats demonstrated equivalent saline baseline operant performance and ED50 for ethanol's rate-suppressing effects. Training sessions were suspended and rats received either a short- (9 days) or long-term (5-week) exposure to regular rat chow diet or thiamine-deficient diet, and received either saline or pyrithiamine injections in a 2 x 2 design. Three additional control groups were maintained on a regular rat chow diet and received supplemental injections of either thiamine+pyrithiamine injections, thiamine+saline injections, or saline+pyrithiamine injections. The controlled diet phase continued until the development of overt signs of thiamine deficiency, at which time thiamine supplements were administered for 4 days. In phase 3, all rats were retrained in the operant task and a second ethanol dose-effect function was generated. A history of thiamine deficiency and recovery failed to shift the behavioral dose-effect functions significantly for ethanol and their associated blood alcohol curves. Most interestingly, significant behavioral sensitization to ethanol's rate suppressant effects was demonstrated in the two control groups of rats receiving regular rat chow diet in combination with supplemental injections of thiamine and either saline or pyrithiamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of electronic, digital blood pressure monitors: perceptions and ease of operation.

Blood pressure (BP) monitors intended for home health care were evaluated according to human-factors criteria, such as ease of operation, clarity of instruction booklet, perceived accuracy, and general preference. In the first phase, five types of BP monitors with various design characteristics were evaluated by pharmacy school students. A general preference was expressed for the electronic, digital BP monitors. In the second phase, four electronic, digital BP monitors were evaluated. Wide variations were observed in the perceptions of and preferences for these monitors. Approximately 64 to 70 per cent of the general preference for any of these instruments could be explained by perception of accuracy, instruction booklet preference, and ease of operation. There was no user preference for LED compared with LCD data readout. When compared with the method used by the evaluator's physician, all four electronic, digital BP monitors received satisfactory ratings.

Emetine myopathy: two case reports with pathobiochemical analysis.

We report two female patients with a history of alcohol abuse presenting with proximal painful muscle weakness following aversion therapy with emetine hydrochloride. Muscle biopsy of Case 1 showed a reversible floccular-shaped loss of myosin ATPase and dehydrogenase, an accumulation of PAS positive material, and a normal lipid content. Repeat biopsy showed core change with no focal loss of myosin ATPase. In Case 2, muscle biopsy was taken 1 month after commencement of emetine therapy and revealed similar but milder changes to Case 1. Electron microscopy revealed Z-band streaming with a decrease or loss of mitochondria. Sarcotubular systems appeared normal in shape and size. Anaerobic glycolysis on homogenate from the initial biopsy of Case 1 showed generalized reduction of lactate formation, which returned to normal in the repeat biopsy.

The effects of scopolamine on extinction and spontaneous recovery.

The effects of scopolamine hydrobromide on baseline extinction levels and spontaneous recovery were assessed. Rats were trained on one of four reinforcement schedules (CRF, FR 10, FR 20, FR 40) with either food or water reinforcement. Scopolamine increased response rates in extinction and spontaneous recovery following training on all four schedules when the reinforcer was water, but had no effect on responding previously maintained by food. The results are discussed in terms of the limitations of a general theory of a cholinergic system mediating all suppressed behavior and the effects of anticholinergic drugs on central thirst mechanisms and consummatory behavior.