15The effect of Lower Esophageal Sphincter (LES) electrical stimulation on LES pressure

Background: Electrical stimulation (ES) of the stomach has been shown to modulate LESP. Electrical stimulation, using neural high frequency stimulation (NGES) can induce contractions of the smooth muscle of the gut. The purpose of this study was to determine if electrical stimulation of the LES can affect LESP. Methods: Four female hound dogs, weight: 20–25 kg, underwent an esophagostomy that allowed the introduction of a sleeve manometry catheter into the esophagus. They were also implanted with a pair of electrodes along the longitudinal axis of the LES. After 3 weeks of recovery, they underwent esophageal manometry recording during control and ES, performed randomly on separate days, using 4 different stimulations: 1‐Low frequency: freq: 6 cycles/min, pulse: 350 milisec, amp: 5 mAmp; 2 High‐frequency: freq: 50 Hz, pulse: 1 milisec, amp: 5 mAmp; 3‐ NGES: freq: 50 Hz, pulse:20 milisec, amp:10 volts; 4‐ High‐frequency, circular: freq: 20 Hz, pulse:1 milisec, amp:5 mAmp. All recordings were performed 1 hour after consumption of 3 ounces of canned dog food, to prevent fluctuations in LESP and under mild sedation (acepromazine 0.5 mg kg^­1). Tests consisted, during ES days, of 3 periods of 20 minutes each: control , stimulation and post stimulation. The effect of NGES was also tested under anesthesia and following administration of L‐NAME 50 mg kg^­1 IV. and also atropine 0.05 mg kg^­1 IV. Analysis: area under the curve (AUC) and pressure were compared among the 3 periods. Data shown as mean ± SD, ANOVA and t‐test, p < 0.05. Results: Sustained increase in LESP was observed during low frequency stimulation, 32.1 ± 12.8 vs. 42.4 ± 18.0 vs. 50.1 ± 23.6, control vs. stimulation vs. post stimulation respectively, p = 0.013. AUC also significantly increased during and after stimulation, 39,320.3 ± 15,722 vs. 51,294 ± 21,826 vs. 59,823.6 ± 28,198.4 mmHgxsec, control vs. stimulation vs. post stimulation respectively, p = 0.01. There was no significant change with other types of ES. NGES induced an initial rise in LESP followed within few seconds by relaxation with slow resumption of pressure over a 1 minute period. L‐NAME increased LESP and augmented the initial rise in LESP following NGES but markedly diminished or abolished the relaxation phase. Atropine lowered LESP and abolished the initial rise in LESP induced by NGES. Conclusions: Low frequency ES of the LES increases LESP in conscious dogs. NGES has dual effect on LESP: an initial stimulation, cholinergically mediated, followed by relaxation mediated by nitric oxide.     

Awareness of HIV/AIDS among primary school pupils in north central region of Nigeria

ObjectiveTo determine the knowledge of HIV/AIDS among primary school pupils in north central area of Nigeria.Methods2000 randomly selected primary school pupils in and around eastern part of Idoma area of Benue state were interviewed using an open-ended questionnaire. Data analysis was done with EPI-INFO 2000. The Chi-square test was used for statistical analysis and the 0.05 level of significance was adopted.ResultsA totle of 1010 males and 990 females at ages between five and sixteen years were drawn from 10 primary schools in the area. Pupils in the higher classes were more knowledgeable and sex difference was not statistically significant. Certain misconceptions were noted.ConclusionsThere is need for health education for all cadres of primary school pupils in the area, which will increase the awareness of the disease.     

Visibility of gallstone fragments at US and fluoroscopy: implications for monitoring gallstone lithotripsy

To assess the value of ultrasound (US), fluoroscopy, and spot radiography in the detection, counting, and measurement of gallstone fragments during lithotripsy, in vitro visibility studies were conducted on fragments from 20 stones. Fluoroscopic visibility was evaluated during and after lithotripsy on 185 fragments placed in an anthropomorphic phantom. Three US experiments were performed on the fragments to study the visibility of fragments as a function of size, the accuracy of the count with large numbers of fragments, and the ability of observers to detect and count fragments larger than both 4 mm and 5 mm. With fluoroscopy, fragment detection rates ranged from 20% (fragments larger than 2.5 mm) to 80% (fragments larger than 4.5 mm). With US, all fragments larger than 1.5 mm were detected, and US was significantly better than fluoroscopy and spot radiography for detection of fragments 2.5 mm or smaller. US was also more accurate than fluoroscopy (11% vs 59% error) in the assessment of the number of fragments. When fragments larger than 4 mm or 5 mm were being counted with US, 92% of the fragments were visualized. The results suggest that US is more accurate for monitoring gallstone lithotripsy than fluoroscopy or spot radiography.     

Cyclopiazonic acid增加SHR和WKY血管平滑肌细胞Ca~(2+)-依赖性外向K~+-电流

采用全细胞及细胞贴附式斑片钳技术记录自发性高血压大鼠(SHR)和Wistar-Kyoto对照鼠(WKY)培养主动脉平滑肌细胞的Ca~(2+)-依赖性外向K~+电流[I_(k(Ca))],测定肌浆网Ca~(2+)泵抑制剂CPA对其影响.CPA能增加I_K(Ca))单通道开放时间,缩短关闭时间,增加全细胞I_(K(Ca))幅度,这些作用与Ca~(2+)相关并可被K~+通道阻断药glybenclamide阻断。CPA作用在SHR和WKY之间无明显差异。结果提示高血压状态下血管平滑肌的功能改变可能与I_(K(Ca))无关。     

Diffuse Conduction Abnormalities in an Adolescent with Familial Sinus Node Disease

We report a case of familial sinus node disease with associated conduction abnormalities in the atrioventricular node and distal conduction system Spontaneous atrial pacemaker activity was absent though the atrium could be depolarized. The pacemaker activity of the heart resided in the atrioventricular junction. The AV node showed impaired automaticity and abnormal conduction properties which partially improved after vagal blockage.