Administration of erythromycin before endoscopy in upper gastrointestinal bleeding: a meta-analysis of randomized controlled trials.

BACKGROUND/AIM: Erythromycin infusion before endoscopy in upper gastrointestinal bleeding (UGIB) has been hypothesized to aid in visualization and reduce the need for second-look endoscopy; however, the results have been controversial. To evaluate further, we performed a meta-analysis comparing the efficacy of erythromycin infusion before endoscopy in acute UGIB. METHODS: Multiple databases were searched (March 2013). Only randomized controlled trials were included in the analysis. A meta-analysis for the effect of erythromycin or no erythromycin before endoscopy in UGIB were analyzed by calculating pooled estimates of primary (visualization of gastric mucosa and need for second endoscopy) and secondary (units of blood transfused, length of hospital stay, duration of the procedure) outcomes. Statistical analysis was performed using RevMan 5.1 (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration). RESULTS: Six studies (N = 558) met the inclusion criteria. Erythromycin infusion before endoscopy in UGIB demonstrated a statistically significant improvement in visualization of the gastric mucosa [odds ratio (OR) 3.43; 95% confidence interval (CI): 1.81 to 6.50, P < 0.01] compared with no erythromycin. In addition, erythromycin infusion before endoscopy resulted in a statistically significant decrease in the need for a second endoscopy (OR 0.47; 95% CI: 0.26 to 0.83, P = 0.01), units of blood transfused (WMD - 0.41; 95% CI: -0.82 to -0.01, P = 0.04), and the duration of hospital stay (WMD - 1.51; 95% CI: -2.45 to -0.56, P < 0.01). CONCLUSIONS: Erythromycin infusion before endoscopy in patients with UGIB significantly improves visualization of gastric mucosa while decreasing the need for a second endoscopy, units of blood transfused, and duration of hospital stay.

Oxidative stress as a prerequisite for aflatoxin production by Aspergillus parasiticus.

The relevance of free radical generation and oxidative stress with regard to aflatoxin production was examined by comparing the oxygen requirement and antioxidant status of a toxigenic strain of Aspergillus parasiticus with that of a nontoxigenic strain at early (trophophase) and late logarithmic (idiophase) growth phases. In comparison to the nontoxigenic strain, wherein the oxygen requirements were relatively unaltered at various growth phases, the toxigenic strain exhibited greater oxygen requirements at trophophase coinciding with onset of aflatoxin production. The activities of antioxidant enzymes such as xanthine oxidase, superoxide dismutase, and glutathione peroxidase and the mycelial contents of thiobarbituric acid-reactive substances as well as of reduced glutathione were all enhanced during the progression of toxigenic strain from trophophase to idiophase. The combined results suggest that aflatoxin production by the toxigenic strain may be a consequence of increased oxidative stress leading to enhanced lipid peroxidation and free radical generation.

Regulation of aflatoxin production by Ca(2+)/calmodulin-dependent protein phosphorylation and dephosphorylation.

To elucidate Ca(2+)-mediated regulation of aflatoxin production, the status of Ca(2+)/calmodulin-dependent protein phosphorylation and dephosphorylation was investigated employing toxigenic and non-toxigenic strains of Aspergillus parasiticus. Incubation of cytoplasmic extracts with [gamma-(32)P]ATP followed by SDS-PAGE and autoradiography revealed total absence of protein phosphorylation during periods corresponding to aflatoxin production in the toxigenic strain (NRRL 2999). In contrast, protein phosphorylation was unaffected in the non-toxigenic strain (SRRC 255). Aflatoxin production in the toxigenic strain was also accompanied by enhanced (26-fold) activity of calcineurin (calmodulin-dependent protein phosphatase 2B) concomitant with a lowered (6-fold) activity of calmodulin-dependent protein kinase. In addition, the in vitro activity of Ca(2+)/calmodulin-dependent protein kinase was susceptible to dose-dependent inhibition by aflatoxin. Since calcineurin remains active in the absence of phosphorylation by calmodulin-dependent protein kinase, it is suggested that calcineurin-mediated dephosphorylation of regulatory enzymes ensures continued production of aflatoxins.

Antiaflatoxigenic activity of eugenol is due to inhibition of lipid peroxidation.

Eugenol inhibited aflatoxin production by Aspergillus parasiticus NRRL 2999 in a dose-dependent manner up to a concentration of 0.75 mmol l-1 without inhibiting growth. When the mould was grown for 3 d in the presence of 0.45 mmol l-1 eugenol (concentration inhibiting aflatoxin production by 50%), in vivo activities of components of polysubstrate monooxygenase were decreased at idiophase, concomitant with decreased activities of enzymes involved in free radical scavenging, lipid peroxidation and maintenance of redox potential. These results indicate that antiaflatoxigenic actions of eugenol may be related to inhibition of the ternary steps of aflatoxin biosynthesis involving lipid peroxidation and oxygenation.

Standardization and demonstration of antibody-coated Candida in urine by direct immunofluorescence test.

Acetone, carbontetrachloride, ethyl alcohol, mixture of ethyl alcohol and acetone, and heat were assessed for fixative property for direct immunofluorescent (IF) staining of antibody-coated Candida cells. The results indicated that ethyl alcohol was the most suitable fixative for the test. Antisera containing 16 units of Candida albicans type A agglutinin were found essential to get optimal detectable fluorescence of antibody-coated yeast cells. IF test showed cross reactivity between the yeasts of C. albicans and C. tropicalis. However, there was no cross reactivity with the conidia of A. flavus. The direct IF test could demonstrate antibody-coated yeast cells and pseudomycelia in deposits of urine in the direct smear. It correlated well with microscopy and culture studies. At times, it could demonstrate the antibody-coated yeasts earlier than routine significant culture. It could also differentiate the significant from non-significant fungal isolates from urine.