Invasive meningococcal disease, Utah, 1995-2005

Trends in invasive meningococcal disease in Utah during 1995-2005 have differed substantially from US trends in incidence rate and serogroup and age distributions. Regional surveillance is essential to identify high-risk populations that might benefit from targeted immunization efforts.     

Comparative effects of diltiazem,propranolol, and placebo on exercise performance using radionuclide ventriculography in patients with symptomatic coronary artery disease: Results of a double-blind,randomized, crossover study

The effects of oral diltiazem (120 mg), propranolol (100 mg), and placebo on exercise performance and left ventricular function were compared before and during symptom-limited supine bicycle exercise by means of multigated radionuclide ventriculography in 12 patients with documented, symptomatic coronary artery disease; a double-blind, randomized crossover protocol was used. Diltiazem increased ejection fraction (EF) at submaximal exercise (+7.0 absolute percentage points, p < 0.02) and maximal exercise (+8.1 percentage points, p < 0.01). Exercise EF was increased by 13.6 percentage points (p < 0.02) in patients with decreased ventricular function (resting EF <50%). Propranolol had no effect on exercise EF at any stage, even when patients with EF <50% were excluded. The increase in total exercise time was significant after diltiazem (+27%, p < 0.01) but not after propranolol (+16%, p = NS). As expected, propranolol decreased both resting (?9 bpm, p < 0.01) and exercise heart rates (?27 bpm, p < 0.001), whereas diltiazem had no significant effect. Propranolol decreased resting diastolic blood pressure (?8 mm Hg, p < 0.02), exercise systolic (?27 mm Hg, p < 0.001) and diastolic (?9 mm Hg, p < 0.01) blood pressures, and rest (p < 0.01) and exercise (p < 0.001) double product. Diltiazem decreased resting systolic blood pressure (?9 mm Hg, p < 0.01) and both resting (?8 mm Hg, p < 0.001) and exercise (?9 mm Hg, p < 0.01) diastolic blood pressures. Diltiazem decreased double product at submaximal (p < 0.005) but not maximal exercise. Angina limited exercise in four patients after diltiazem compared to eight and seven patients after placebo and propranolol respectively (p < 0.05). Thus, diltiazem improved exercise performance with the use of radionuclide ventriculography during symptom-limited supine bicycle ergometry to a greater extent than did propranolol or placebo, and this effect was most apparent in those with decreased left ventricular function.     

An effect of corticosteroids and 100% oxygen on aryl hydrocarbon hydroxylase, cytochrome-c reductase, and free radical formation by rat lung microsomes.

Activity of aryl hydrocarbon hydroxylase (AHH), cytochrome c-reductase, and NADPH oxidase, and epinephrine oxidation to adrenochrome were determined in lung microsomes from intact, adrenalectomized, and adrenalectomized cortisol-treated female rats under ambient and hyperoxic conditions. Microsomal adrenochrome formation, which is initiated by superoxide anion or other free radicals, was increased by adrenalectomy and decreased by cortisol treatment. Exposure of animals to 100% oxygen caused a further increase in adrenochrome formation. NADPH-cytochrome c-reductase and AHH activities were increased in incubations of microsomes from animals which had received cortisol in vivo while adrenalectomy led to decreases activity. NADPH oxidase activity was increased by cortisol in lung microsomes in the presence of either epinephrine or cytochrome c. Epinephrine conversion to adrenochrome in the presence of lung microsomes was blocked by SOD, but NADPH-cytrochrome c-reductase and AHH activity were unaffected.     

Application of body surface mapping to exercise testing: S-T80 isoarea maps in patients with coronary artery disease

Body surface electrocardiographic maps were recorded before and after exercise in 25 men with angiographically documented coronary disease. Torso potential distributions at 192 locations were derived from a 32 lead electrode array using methods previously described in our laboratory. The S-T segment was characterized by the spatial distribution of the integral of S-T segment voltage over 80 ms (S-T₈₀). Body surface regions where the S-T₈₀ areas were —8 mV·ms or greater were identified in 18 of 25 patients. The most negative S-T₈₀ site on the map was called the “S-T₈₀ minimum.” The S-T₈₀ minima were located 1 or 2 electrode rows away from the standard V₄–V₆ electrode positions in 6 of 10 patients who developed S-T₈₀ areas of —8 mV·ms or greater. Our data suggest that standard electrocardiographic leads may not be optimal for identifying S-T segment depression in all patients with coronary disease. Furthermore, body surface mapping during exercise provides a more quantitative and qualitative method for characterizing the ischémic response to exercise.     

Comparative effect of counterpulsation and bypass on left ventricular myocardial oxygen consumption and dynamics before and after coronary occlusion

In this preparation counterpulsation effect was found equivalent to 42 ± 7 per cent of complete left ventricular bypass before, and 46 ± 9 per cent post-coronary occlusion. We conclude that counterpulsation is effective mainly by reducing a major determinant of myocardial oxygen consumption, i.e., afterload, whereas left ventricular bypass by reducing primarily preload results in secondary afterload reduction when peripheral resistance is unchanged. At the higher left ventricular bypass levels, reduction of myocardial oxygen consumption is far greater than during balloon counterpulsation. Acute functional loss of myocardium does not alter the effect of these assist methods regarding the reduction of myocardial oxygen consumption. Whether selection of either method for clinical application should be made only on the basis of its capability for reduction of myocardial oxygen consumption remains to be justified by conclusive demonstration of beneficial effect of reduction of myocardial oxygen consumption in the specific circulatory disorders.     

A comparison of acid-elution techniques and alpha-fetoprotein levels for the detection of fetomaternal bleeding

Practical and reliable methods to identify and/or quantitate fetal blood are becoming more important in the modern practice of obstetrics. In this study, two commercially available acid-elution techniques were compared with plasma -alpha-fetoprotein (AFP) by simultaneously testing samples of fetal blood mixed with adult blood in fixed ratios. Thirty-one samples representing a range of amounts of fetomaternal hemorrhage, from 0.024 to 48 ml, were analyzed. The acid-elution techniques were equally effective in detecting fetomaternal hemorrhage greater than 15 ml, but the bmc Reagent set was the most accurate for detection of small numbers of fetal erythrocytes. The accuracy of AFP was greater than that of either acid-elution technique, but its clinical usefulness is limited by the necessity for a prehemorrhage sample.     

Hazards of calcium gluconate therapy in the newborn infant: intra-arterial injection producing intestinal necrosis in rabbit ileum

Five infants received 10% calcium gluconate via umbilical artery catheters, which resulted in intestinal bleeding and lesions of the buttock, anus, groin, and thigh. The effects of intra-arterial calcium gluconate in two animal models were investigated. Injection of calcium into the aorta in the region of the posterior mesenteric artery resulted in immediate hyperperfusion of the descending colon; this may be an early hemodynamic response to injury in the area of colon supplied by this vessel. Injections into the arterial arcade of the rabbit ileum resulted in intestinal necrosis and villous atrophy. The use of umbilical artery catheters for administration of calcium gluconate is potentially hazardous.