The cold pressor test: Vascular and myocardial response patterns and their stability

The purposes of the present study were to compare the cardiovascular response patterns evoked by three versions of the cold pressor test (either forehead stimulation or hand or foot immersion) and to determine the reproducibility of the responses over a 2-week interval. Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, and systolic time intervals were obtained during rest and during the cold pressor test in 42 young men. Across conditions, the pressor response was supported by peripheral resistance increases with concomitant stroke volume decreases. Although the response panerns were generally similar across sites, exceptions were apparent for heart rate. Forehead stimulation was characterized by no significant change in heart rate, whereas limb (hand or foot) immersion was associated with significant heart rate acceleration. The responses elicited by the three cold pressor test conditions were reliable and showed little evidence of attenuation over the test-retest interval.     

Malignant Ventricular Tachycardia During Propafenone Treatment in a Child with Junctional Automatic Tachycardia: Effectiveness of Intravenous Molar Sodium Lactate

Propafenone may aggravate the preexisting arrhythmia or induce another one. Usually, such proarrhythmic effects occur in patients with spontaneous ventricular arrhythmias and/or coronary heart disease with poor left ventricular function. We report the case of a 5-year-old girl with Junctional automatic tachycardia and no structural heart disease, in whom malignant ventricular tachycardia occurring during propafenone treatment could be terminated by molar sodium lactate (MSL) infusion. The serum propafenone level obtained before MSL infusion was within the therapeutic range. Two hypothesis could explain the beneficial effects of MSL in our patient: (1) alkalinization facilitates the cell membrane hyperpolarization and thus can decrease the voltage-dependent effect of Class Ic drugs, (2) alkalinization could displace propafenone from its tissue receptor sites by an increase in the nonionized fraction.     

Potential Efficacy of a Delta 5-Aminolevulinic Acid Bioadhesive Gel Formulation for the Photodynamic Treatment of Lesions of the Gastrointestinal Tract in Mice

A delta 5-aminolevulinic acid (ALA) bioadhesive gel has been developed and evaluated in an in-vivo mouse model for photodynamic treatment of gastric cancer or Barrett's oesophagus. Four gels were tested: noveon AA-1, keltrol T, lutrol and blanose. An initial in-vitro study of gel adhesion showed that noveon and keltrol had longer polyethylene transit times than lutrol and blanose. In-vivo assays indicated that protoporphyrin IX was synthesized by gastric mucosa when ALA-noveon and ALA-lutrol were used (preferable results for noveon). Keltrol was eliminated from the study after these investigations. Only ALA-noveon gel was retained for studies of the relationship between ALA dose and fluorescence. Fluorescence measurements in-vivo showed that ALA concentration and application time had an influence on protoporphyrin IX synthesis. Maximum intensity (2091 counts s^?) was found with 2 mg mL^? ALA, and fluorescence intensities differed with application time, reaching 1805 counts s^? after 240 min. ALA-noveon, showing good adhesion and enabling efficient diffusion of ALA at a pH < 6, was considered the best formulation for maintaining ALA stability.     

Influence of liver cirrhosis on sertraline pharmacokinetics

Sertraline is a serotonin reuptake inhibitor. The enhancement of serotoninergic transmission is associated with antidepressant activity. In order to determine the pharmacokinetics of sertraline in patients with chronic stable hepatic insufficiency, 10 patients were matched (age, weight, sex) with 10 healthy subjects in an open study. Each participant received a single capsule containing the equivalent of 100  mg sertraline base. Blood samples were taken during 264  h after administration for measurement of plasma concentrations of sertraline. The results confirm that the oral clearance of sertraline is reduced with a 1.7-fold increase in C _max and a significant prolongation in elimination half-life in hepatically impaired patients     

Gianotti-Crosti syndrome: a study of 26 cases

We have studied 26 patients presenting with a symmetrical papular or papulovesicular acrolocated eruption of more than 10 days duration. Mean age at onset was 2 years (range 10 months to 5.75 years). Lymphadenopathy was noted in eight cases, and hepatomegaly in one case. In 12 cases, histopathology and direct immunofluorescence were non-contributory. Cytolytic hepatitis occurred in one case and was associated with HBs antigenemia. A history of recent immunization was given in two cases. There was serological evidence of recent Epstein-Barr virus infection in seven out of 13 cases tested. Coxsackie B viruses were isolated from three patients, and cytomegalovirus was probably associated with the syndrome in one case. We conclude that the Gianotti-Crosti syndrome is not rare in France, and that non-hepatitis B virus (HBV)-associated cases are more frequent than the classical HBV-associated papular acrodermatitis of childhood.     

Selenium in Plasma and Erythrocytes in Patients with Down's Syndrome and Healthy Controls

ABSTRACT. The mean plasma selenium concentration (P-Se) in 65 patients with Down's syndrome (DS) did not differ from that in 90 healthy controls. The concentration of selenium in the erythrocytes (E-Se) was higher in DS patients than in controls ( p <0.001). P-Se and E-Se increased progressively with age through childhood in both DS children and controls. The former children, however, started out with higher levels of E-Se and reached adult concentrations earlier (at 7-17 years) than controls (18 years). Adult DS patients and controls did not differ in their mean P-Se or E-Se concentration. There was a significant correlation between P-Se and E-Se both in DS patients and in controls. In DS patients each of these two variables was significantly correlated to glutathione peroxidase (GSH-Px) activity in erythrocytes. A sex difference in the DS children, but not in the controls, was observed with regard to P-Se and E-Se levels, these being higher in DS girls during childhood (0-17 years). This was in accordance with an earlier finding of higher GSH-Px activity in DS girls than in DS boys.     

Elevated Serum Selenium in Diabetic Children

ABSTRACT. Twenty-seven diabetic children, 16 girls and 11 boys, 5–18 years of age, with a duration of the disease ranging from 2–15 years, comprised the study group. Thirteen children with a similar age and sex distribution, living in the same area served as healthy controls. All 40 children had a normal growth pattern. The mean serum selenium concentration in the diabetic children, determined by neutron activation analysis, was 7.4 ± 0.8 μg/100 ml (mean ± SD) and in the healthy controls 6.5 ± 0.8 μg/100 ml. The difference between the two groups was statistically highly significant ( p < 0.01). Boys and girls in both groups had nearly identical mean serum selenium levels and no correlation was observed between the selenium concentrations and either the age, weight or height of the children or the indicators of diabetic control. The selenium status in diabetic children has not been reported previously. The possibility of elevated serum selenium in diabetic children in response to altered lipid metabolism is discussed.     

Stimulus dimensions of the cold pressor test and the associated patterns of cardiovascular response

Hemodynamics of the cold pressor response in relation to its pain and nonpain stimulus components were investigated in normotensive college men using the foot and forehead cold pressor tasks. Mechanisms of pain- and non-pain-related increases in blood pressure were analyzed as residual effects of concurrent changes in total peripheral resistance and cardiac output. The identified partial relationships suggested that the response pattern associated with pain included positive change both in cardiac output and in total peripheral resistance, whereas the nonpain-related response was limited to an increase in total peripheral resistance. Analyses of individual differences in car-diovascular responses to pain further indicated that pain-related increments in blood pressure were mediated by a steeper rise in total peripheral resistance, an increase in heart rate, and an apparent increase in preload. At baseline, high reactors to pain manifested relatively elevated total perpheral resistance, diminished cardiac output, and an indication of a reduced inotropic state, suggesting that altered basal homeostasis may discriminate normotensive individuals displaying heightened cardiovascular reactivity to aversive cold stimulation.