Haemodynamic effects of rectal methohexitone for induction of anaesthesia in children

Pulsed Doppler and two-dimensional echocardiography were used to determine the haemodynamic effects of rectal methohexitone in 12 children 32.4 +/- 3.8 months old and weighing 13.3 +/- 1.1 kg (mean +/- SEM). Heart rate, blood pressure and echocardiographic measurements of cardiac output, stroke volume and left ventricular end-diastolic and end-systolic volumes were obtained prior to the induction of anaesthesia. Anaesthesia was induced with 25 mg.kg-1 two per cent rectal methohexitone. Immediately following the onset of sleep all cardiovascular measurements were repeated. Following the induction of anaesthesia with rectal methohexitone there was a significant increase in heart rate. Blood pressure, cardiac index, stroke volume and ejection fraction were unchanged. It is concluded that rectal administration of two per cent methohexitone for the induction of anaesthesia in healthy paediatric patients has minimal haemodynamic effect.     

Functional abnormalities of experimental autogenous vein graft neoendothelium.

When a vein is grafted into the arterial circulation, the endothelium of the graft is damaged. Regeneration of an intact neoendothelium occurs, but the functional properties of this surface have not been clarified. In this study, the functional integrity of the neoendothelium of veins grafted into the carotid artery of the rabbit was assessed through the use of acetylcholine and histamine to stimulate the production of the important endothelium-derived relaxing factor (EDRF). Control veins, precontracted with norepinephrine [10(-5) M], relaxed after exposure to acetylcholine [( 10(-7) M], 42.4% +/- 6.4%, p = 0.008) and histamine [( 10(-6) M], 30.6% +/- 4.3%, p = 0.03). This relaxation response was abolished after mechanical removal of the endothelium. By contrast, neither acetylcholine nor histamine caused an endothelium-dependent relaxation in the vein grafts, even though scanning electron microscopy demonstrated the presence of a morphologically intact endothelium. However, addition of stabilized EDRF purified from cultured endothelial cells induced relaxation of the vein grafts (35.8% +/- 3.6%, p = 0.002). These data indicate that vein graft endothelium is unable to produce EDRF in response to exposure to acetylcholine or histamine. The inability to produce this potent smooth muscle cell relaxing factor and anti-aggregatory substance may be a predisposition to vein graft failure.     

Clear cell adenocarcinoma of the vagina and cervix: incidence, undetected disease, and diethylstilbestrol

We conducted an incidence study to determine the occurrence rates of clear cell adenocarcinoma (CCAC) of the vagina and cervix in young women (born in 1940 and thereafter), and a case-series analysis, focusing on the maternal history of pregnancy and delivery and in-utero exposure to diethylstilbestrol (DES). Overall, 10 cases of CCAC had been listed in the files of the Connecticut State Tumor Registry prior to the study, and each of the 10 cases were confirmed as valid. In addition, another 10 cases, all previously undetected, were found after the tissue slides of young women listed as having other cancers of the vagina and cervix were reviewed by expert pathologists, suggesting that prior estimates of the incidence rate for CCAC must be misleading unless special efforts are taken to identify undetected cases. The incidence rates of vaginal CCAC (11 cases total) were highest in 1975-1979, and decreased slightly during 1980-1982. In the cervix (nine cases total), the rate increased consistently since 1970. History of in-utero exposure to diethylstilbestrol was obtained for five of eight vaginal cases and four of eight cervical cases of CCAC. In all nine cases, exposure to diethylstilbestrol was associated with a history of bleeding during the pregnancy or prior miscarriage. We conclude that the finding of stable (or rising) incidence rates for CCAC occurring nearly 30 years after the marked decrease in diethylstilbestrol sales emphasizes the need for continued clinical and epidemiologic studies of the etiology and clinical course of CCAC.     

Regional differences in oesophageal motor function

Abstract  We tested the hypotheses that oesophageal bolus transit and motor function vary regionally, with bolus viscosity and with body position. In healthy volunteers, we measured the bolus head advance time, bolus presence time and bolus transit time in the proximal and distal oesophagus using water and viscous materials. We compared concurrent manometric responses. Bolus head advance time, bolus presence time and bolus transit time were longer in the distal oesophagus during water and viscous swallows in the upright and supine positions. The total bolus head advance time and transit time, measured across the entire oesophageal body, were shorter for water than viscous swallows. The amplitudes of peristaltic pressure waves were lower for viscous swallows, and varied as a function of region. These studies demonstrated true functional differences between the proximal and distal oesophagus using multichannel intraluminal impedance and that the viscosity of the bolus is a determinant of oesophageal function.