Correlation of susceptibility of Cryptococcus neoformans to amphotericin B with clinical outcome.

Testing of Cryptococcus neoformans for susceptibility to antifungal drugs by standard microtiter methods has not been shown to correlate with clinical outcomes. This report describes a modified quantitative broth macrodilution susceptibility method showing a correlation with both the patient's quantitative biological response in the cerebrospinal fluid (CSF) and the survival of 85 patients treated with amphotericin B (AMB). The Spearman rank correlation between the quantitative in vitro measure of susceptibility and the quantitative measure of the number of organisms in the patient's CSF was 0.37 (P < 0.01; 95% confidence interval [95% CI], 0.20, 0.60) for the first susceptibility test replicate and 0.46 (P < 0.001; 95% CI, 0.21, 0.62) for the second susceptibility test replicate. The median in vitro estimated response (defined as the fungal burden after AMB treatment) at 1.5 mg/liter AMB for patients alive at day 14 was 5 CFU (95% CI, 3, 8), compared to 57 CFU (95% CI, 4, 832) for those who died before day 14. These exploratory results suggest that patients whose isolates show a quantitative in vitro susceptibility response below 10 CFU/ml were more likely to survive beyond day 14.

Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition.

BACKGROUND: Ascorbic acid (vitamin C) might be protective for several chronic diseases. However, findings from prospective studies that relate ascorbic acid to cardiovascular disease or cancer are not consistent. We aimed to assess the relation between plasma ascorbic acid and subsequent mortality due to all causes, cardiovascular disease, ischaemic heart disease, and cancer. METHODS: We prospectively examined for 4 years the relation between plasma ascorbic acid concentrations and mortality due to all causes, and to cardiovascular disease, ischaemic heart disease, and cancer in 19 496 men and women aged 45-79 years. We recruited individuals by post using age-sex registers of general practices. Participants completed a health and lifestyle questionnaire and were examined at a clinic visit. They were followed-up for causes of death for about 4 years. Individuals were divided into sex-specific quintiles of plasma ascorbic acid. We used the Cox proportional hazard model to determine the effect of ascorbic acid and other risk factors on mortality. FINDINGS: Plasma ascorbic acid concentration was inversely related to mortality from all-causes, and from cardiovascular disease, and ischaemic heart disease in men and women. Risk of mortality in the top ascorbic acid quintile was about half the risk in the lowest quintile (p<0.0001). The relation with mortality was continuous through the whole distribution of ascorbic acid concentrations. 20 micromol/L rise in plasma ascorbic acid concentration, equivalent to about 50 g per day increase in fruit and vegetable intake, was associated with about a 20% reduction in risk of all-cause mortality (p<0.0001), independent of age, systolic blood pressure, blood cholesterol, cigarette smoking habit, diabetes, and supplement use. Ascorbic acid was inversely related to cancer mortality in men but not women. INTERPRETATION: Small increases in fruit and vegetable intake of about one serving daily has encouraging prospects for possible prevention of disease.

Vitamin C and hyperglycemia in the European Prospective Investigation into Cancer--Norfolk (EPIC-Norfolk) study: a population-based study.

OBJECTIVE: To examine the cross-sectional association between plasma vitamin C, self-reported diabetes, and HbA1c. RESEARCH DESIGN AND METHODS: Data from a population-based study of diet, cancer, and chronic disease were analyzed. A total of 2,898 men and 3,560 women 45-74 years of age who were registered with general practices in Norfolk, U.K., were recruited to the European Prospective Investigation Into Cancer-Norfolk study between 1995 and 1998. RESULTS: Mean plasma vitamin C levels were significantly higher in individuals with HbA1c levels < 7% than in those with self-reported diabetes or prevalent undiagnosed hyperglycemia (HbA1c > or = 7%). An inverse gradient of mean plasma vitamin C was found in both sexes across quintiles of HbA1c distribution < 7%. The odds ratio (95% CI) of having prevalent undiagnosed hyperglycemia per 20 micromol/l (or 1 SD) increase in plasma vitamin C was 0.70 (0.52-0.95) (adjusted for sex, age, BMI, waist-to-hip ratio, tertiary education, any use of dietary supplements, vegetarian diet, alcohol consumption, physical activity, dietary vitamin E, dietary fiber, dietary saturated fat, and smoking history). The unadjusted change in HbA1c per 20 micromol/l increase in vitamin C estimated by linear regression was -0.12% (-0.14 to -0.09) in men and -0.09% (-0.11 to -0.07) in women. After adjusting for the possible confounders, these values were -0.08% (-0.11 to -0.04) in men and -0.05% (-0.07 to -0.03) in women. CONCLUSIONS: An inverse association was found between plasma vitamin C and HbA1c. Dietary measures to increase plasma vitamin C may be an important public health strategy for reducing the prevalence of diabetes.

Guinea pig liver transglutaminase: A modified purification procedure affording enzyme with superior activity in greater yield.

Tissue transglutaminase purified from guinea pig livers has a very broad substrate specificity in comparison with other members of the transglutaminase family and therefore is useful for substrate analogue kinetic studies. Modifications made in our laboratory to the standard purification protocol (J. E. Folk and S. I. Chung, 1985, Methods Enzymol. 113, 358-364) have yielded a 28% increase in specific activity and 55% increase in overall yield, while reducing the number of steps to the purification. Herein we report some of the highest yields and specific activities for guinea pig liver transglutaminase found in the literature, as well as the use of lyophilization as a solution to the long-standing problem of enzyme stability during storage.

Plasma vitamin C: what does it measure?

OBJECTIVE: To examine the association between self-reported consumption of foods and plasma vitamin C levels. DESIGN: A cross-sectional analysis of dietary data and plasma vitamin C levels. Subjects placed the following foods into frequency categories: fresh fruit, leafy greens, other vegetables, fatty fish, other fish, chicken, meat, meat products, eggs, cheese and brown bread. The six frequency categories ranged from 'never' to 'at least daily'. Plasma vitamin C was measured by fluorometric assay. SETTING: A population-based cohort study in Norfolk, UK. SUBJECTS: 598 men and 566 women aged 45-74 years not taking vitamin supplements. RESULTS: Plasma vitamin C was positively correlated with intake of fresh fruit (r=0.29 in men and r=0.25 in women, P<0.001), leafy greens (r=0.20 in men P<0.001, r=0.13 in women P<0.01), other vegetables (r=0.20 in men P<0.001, r=0.14 in women P<0.01) and brown bread (r=0.28 in men, r=0.17 in women, P<0.001) and negatively associated with intake of meat products (r=-0.13 in men P=0.02, r=-0.10 in women P<0.01). The difference in plasma vitamin C between never and daily eaters of brown bread was 13.6 micronol l(-1) in men and 9.9 micromol l(-1) in women, P<0.001. CONCLUSIONS: These data suggest that plasma vitamin C is not only a marker of foods rich in vitamin C but of certain patterns of food consumption. Such patterns are likely to be population specific and might explain inconsistencies in biomarker-disease associations.

Penicillin vs. erythromycin in the treatment of diphtheria.

In an open-label, randomized trial, 44 Vietnamese children with diphtheria were given penicillin therapy (intramuscular benzylpenicillin, 50,000 U/[kg.d] for 5 days and then oral penicillin, 50 mg/[kg.d] for 5 days), and 42 were given erythromycin therapy (50 mg/[kg.d] orally for 10 days). There were no differences in times to membrane clearance or bacteriologic clearance, but median times to fever clearance were 27 hours (95% confidence interval [CI], 19-30; range, 0-124 hours) for penicillin recipients and 46 hours (95% CI, 34-54; range, 0-148 hours) for erythromycin recipients (P = .0004). In the penicillin group, acute treatment failed for one patient, and one patient relapsed. Three patients in the penicillin group developed diphtheritic myocarditis as evidenced by abnormal electrocardiograms. Erythromycin did not cause prolongation of the QT interval corrected for heart rate. Cultures of specimens from 15 patients (17.4%) were positive for toxigenic Corynebacterium diphtheriae. All isolates were susceptible to penicillin, but for isolates (27%), all of which were from patients who received penicillin treatment, were resistant to erythromycin (minimum inhibitory concentrations, > 64 mg/L). Penicillin is recommended as first-line treatment for diphtheria in Vietnam.

Intracorporal injection of hSlo cDNA in rats produces physiologically relevant alterations in penile function.

The Ca2+-sensitive K+ channel (maxi-K+) is an important modulator of corporal smooth muscle tone. The goal of these studies was twofold: 1) to determine the feasibility of transfecting corporal smooth muscle cells in vivo with the hSlo cDNA, which encodes for the human smooth muscle maxi-K+ channel, and 2) to determine whether transfection of the maxi-K+ channel would affect the physiological response to cavernous nerve stimulation in a rat model in vivo. Intracorporal microinjection of pCMVbeta/Lac Z DNA in 10-wk-old rats resulted in significant incorporation and expression of beta-galactosidase activity in 10 of 12 injected animals for up to 75 days postinjection. Moreover, electrical stimulation of the cavernous nerve revealed that, relative to the responses obtained in age-matched control animals (N = 12), intracavernous injection of naked pcDNA/hSlo DNA was associated with a statistically significant elevation in the mean amplitude of the intracavernous pressure response at all levels of current stimulation (range 0.5-10 mA) at both 1 mo (N = 5) and 2 mo (N = 8) postinjection. Furthermore, qualitatively similar observations were made at 3 mo (N = 2) and 4 mo (N = 2) postinjection. These data indicate that naked hSlo DNA is quite easily incorporated into corporal smooth muscle and, furthermore, that expression is sustained for at least 2 mo in corporal smooth muscle cells in vivo. Finally, after expression, hSlo is capable of measurably altering nerve-stimulated penile erection. Taken together, these data provide compelling evidence for the potential utility of gene therapy in the treatment of erectile dysfunction.

Comparison of artemisinin suppositories, intramuscular artesunate and intravenous quinine for the treatment of severe childhood malaria.

Severe malaria remains a major cause of mortality and morbidity for children living in many tropical regions. With the emergence of strains of Plasmodium falciparum resistant to both chloroquine and quinine, alternative antimalarial agents are required. The artemisinin group of compounds are rapidly effective in severe disease when given by intramuscular or intravenous injection. However, these routes of administration are not always available in rural areas. In an open, randomized comparison 109 Vietnamese children, aged between 3 months and 14 years, with severe P.falciparum malaria, were allocated at random to receive artemisinin suppositories followed by mefloquine (n = 37), intramuscular artesunate followed by mefloquine (n = 37), or intravenous quinine followed by pyrimethamine/sulfadoxine (n = 35). There were 9 deaths: 2 artemisinin, 4 artesunate and 5 quinine-treated children. There was no difference in fever clearance time, coma recovery, or length of hospital stay among the 3 groups. However, parasite clearance times were significantly faster in artemisinin and artesunate-treated patients than in those who received quinine (P < 0.0001). Both artemisinin and artesunate were very well tolerated, but children receiving these drugs had lower peripheral reticulocyte counts by day 5 of treatment than those in the quinine group (P = 0.011). No other adverse effect or toxicity was found. There was no treatment failure in these 2 groups, but 4 patients in the quinine group failed to clear their parasites within 7 d of starting treatment and required alternative antimalarial therapy. Artemisinin suppositories are easy to administer, cheap, and very effective for treating children with severe malaria. In rural areas where medical facilities are lacking these drugs will allow antimalarial therapy to be instituted earlier in the course of the disease and may therefore save lives.

Quinolone-resistant Salmonella typhi in Viet Nam: molecular basis of resistance and clinical response to treatment.

Nalidixic acid-resistant Salmonella typhi (NARST) was first isolated in Viet Nam in 1993. Analysis of the quinolone resistance-determining region of gyrA in 20 NARST isolates by polymerase chain reaction and single-stranded conformational polymorphism yielded two novel patterns: pattern II corresponding to a point mutation at nucleotide 87 Asp-->Gly (n = 17), and pattern III corresponding to a point mutation at nucleotide 83 Ser-->Phe (n = 3). In trials of short-course ofloxacin therapy for uncomplicated typhoid, 117 (78%) of 150 patients were infected with multidrug-resistant S. typhi, 18 (15%) of which were NARST. The median time to fever clearance was 156 hours (range, 30-366 hours) for patients infected with NARST and 84 hours (range, 12-378 hours) for those infected with nalidixic acid-susceptible strains (P < .001). Six (33.3%) of 18 NARST infections required retreatment, whereas 1 (0.8%) of 132 infections due to susceptible strains required retreatment (relative risk = 44; 95% confidence interval = 5.6-345; P < .0001). We recommend that short courses of quinolones not be used in patients infected with NARST.