False-positive results obtained with the Alexon ProSpecT Cryptosporidium enzyme immunoassay.
(57/13394)
Cryptosporidium is known to cause diarrhea in immunocompromised patients and is also associated with outbreaks of disease due to food-borne and waterborne parasites. Traditional procedures, involving iodine staining of wet mounts of stool sediments and trichrome staining, lack the sensitivity to detect Cryptosporidium. Special staining procedures, such as the modified acid-fast and safranin stains, are generally employed. Less labor-intensive antigen detection assays have simplified detection; however, careful attention to local epidemiology is important because false-positive tests occur. Here, we report two incidents involving 62 false-positive results obtained with the Alexon ProSpecT Cryptosporidium enzyme immunoassay, which were deemed false-positive based on negative results obtained from extensive microscopic examinations. (+info)
First-glance diagnosis of Strongyloides stercoralis autoinfection by stool microscopy.
(58/13394)
We report a case of autoinfection due to Strongyloides stercoralis in a 27-year-old Ethiopian AIDS patient living in Germany for nearly 3 years. This case was diagnosed on the basis of a single-view field in microscopy of a freshly obtained formalin-fixed stool specimen showing both rhabditiform and filariform larvae. The diagnosis of autoinfection by microscopy is discussed in detail. (+info)
Septicemia caused by dysgonic fermenter 3 in a severely immunocompromised patient and isolation of the same microorganism from a stool specimen.
(59/13394)
Dysgonic fermenter 3 (DF-3)-associated bacteremia occurred in a febrile patient with acute myelocytic leukemia during aplasia. Another DF-3 isolate, identical by ribotyping, was grown 10 weeks later from stool collected in the absence of diarrhea. This is the first case in which DF-3 was isolated from blood and stool specimens from the same patient. (+info)
The retention and distribution by healthy young men of stable isotopes of selenium consumed as selenite, selenate or hydroponically-grown broccoli are dependent on the isotopic form.
(60/13394)
Twenty-seven healthy young men were randomly assigned to diets that supplied low (32.6 microg/d) or high (226.5 microg/d) levels of selenium for a 105-d study. After consuming the diets for 85 d, subjects were fed a test meal that contained 74Se in the form of selenite or selenate and 82Se incorporated into hydroponically-raised broccoli. Urine, fecal and blood samples were collected daily. Isotope absorption was not different (P > 0.05) for selenate and Se in broccoli; Se absorption from selenite was highly variable and was not included in statistical analyses. Significantly more isotope was absorbed by subjects fed the high Se diet (P = 0. 015). Urinary isotope excretion was greater when selenate was fed than when broccoli was fed (P = 0.0001), and consequently more Se from broccoli (as compared to selenate) was retained (59.2 +/- 2.4 and 36.4 +/- 4.6% for Se in broccoli and selenate, respectively; P = 0.0001). Despite the higher retention, less isotope from broccoli than from selenate was present in the plasma. Plasma proteins separated by gel permeation chromatography showed that most of the isotopes were distributed between two medium molecular weight peaks. Less isotope was found in plasma proteins of subjects fed the high Se diet, but the form of Se had no effect on isotope distribution. These results show that dietary Se intake alters the retention of stable isotopes of Se and that humans retain and distribute Se from broccoli in a different manner than Se from inorganic salts. (+info)
Increased fecal bile acid excretion and changes in the circulating bile acid pool are involved in the hypocholesterolemic and gallstone-preventive actions of psyllium in hamsters.
(61/13394)
The lipid-lowering effect of psyllium (PSY) is well established. Enhanced fecal bile acid excretion and a stimulation of hepatic bile acid synthesis are discussed as primary mechanisms of this action. To further examine the effect of bile acid excretion and specifically of compositional alterations in the bile acid pool on the cholesterol-lowering and gallstone-preventing action of PSY, male golden Syrian hamsters were fed lithogenic diets containing 5 g/100 g fat, 0.4 g/100 g cholesterol and 0 (control), 4 or 6% PSY or 1% cholestyramine (CHY). PSY significantly lowered plasma total cholesterol and triacylglycerol at a magnitude comparable to that induced by CHY. Although hepatic cholesteryl ester accumulation was completely inhibited by CHY, PSY did not prevent the hepatic storage of esterified cholesterol. PSY and CHY caused distinct alterations in the bile acid profile. PSY caused a selective reduction of taurine-conjugated bile acids, especially of taurochenodeoxycholate. As a result, the glycine:taurine conjugation and the cholate:chenodeoxycholate ratios were significantly higher in PSY-fed hamsters. PSY and CHY normalized the lithogenic index and prevented cholesterol gallstone formation compared with controls. Daily fecal bile acid excretion was approximately 400% greater in hamsters fed 6% PSY, whereas CHY caused an 11-fold increase. Daily neutral sterol excretion did not differ in PSY-fed hamsters but was >100% greater in those fed CHY than in controls. These data emphasize the potent lipid-lowering effect of PSY. Increased fecal bile acid excretion and alterations of the circulating bile acid pool by removal of dihydroxy bile acids (e.g., taurochenodeoxycholate) appear to be main modulators of the hypocholesterolemic action of PSY by leading to an up-regulation of hepatic bile acid synthesis. (+info)
Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance. The Infectious Intestinal Disease Study Executive.
(62/13394)
OBJECTIVE: To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance. DESIGN: Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance. SETTING: 70 general practices throughout England. PARTICIPANTS: 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients. MAIN OUTCOME MEASURES: Incidence of infectious intestinal disease in community and reported to general practice. RESULTS: 781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified. CONCLUSIONS: Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism. Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered. (+info)
Stool microflora in extremely low birthweight infants.
(63/13394)
AIM: To serially characterise aerobic and anaerobic stool microflora in extremely low birthweight infants and to correlate colonisation patterns with clinical risk factors. METHODS: Stool specimens from 29 infants of birthweight <1000 g were collected on days 10, 20, and 30 after birth. Quantitative aerobic and anaerobic cultures were performed. RESULTS: By day 30, predominant species were Enterococcus faecalis, Escherichia coli, Staphylococcus epidermidis, Enterbacter cloacae, Klebsiella pneumoniae, and Staphylococcus haemolyticus. Lactobacillus and Bifidobacteria spp were identified in only one infant. In breast milk fed (but not in formula fed) infants, the total number of bacterial species/stool specimen increased significantly with time (2.50 (SE 0.34) on day 10; 3.13 (0.38) on day 20; 4.27 (0.45) on day 30) as did quantitative bacterial counts; Gram negative species accounted for most of the increase. On day 30, significant inverse correlations were found between days of previous antibiotic treatment and number of bacterial species (r=0.491) and total organisms/g of stool (r=0.482). Gestational age, birthweight, maternal antibiotic or steroid treatment, prolonged rupture of the membranes, and mode of delivery did not seem to affect colonisation patterns. CONCLUSIONS: The gut of extremely low birthweight infants is colonised by a paucity of bacterial species. Breast milking and reduction of antibiotic exposure are critical to increasing fecal microbial diversity. (+info)
Role of cytochrome P-450 2E1 in methacrylonitrile metabolism and disposition.
(64/13394)
Methacrylonitrile (MAN) is a widely used aliphatic nitrile and is structurally similar to the known rat carcinogen and suspected human carcinogen acrylonitrile (AN). There is evidence that AN is metabolized via the cytochrome P-450 (CYP) 2E1. Recently, we identified two biliary conjugates originating from the interaction of MAN and its epoxide with glutathione. Mercapturic acids formed via the degradation of the two conjugates were also identified in rat and mouse urine. Additionally, a significant portion of MAN was eliminated in the expired air as CO2 (formed via the epoxide pathway) and unchanged MAN. The objective of the present work was to determine whether CYP2E1 is involved in the oxidative metabolism of MAN as was suggested for AN. 2-14C-MAN was administered to CYP2E1-null or wild-type mice by gavage at 12 mg/kg. Although total urinary and fecal excretion of MAN-derived radioactivity was slightly different in CYP2E1-null versus wild-type mice, the ratio of mercapturic acids originating from the epoxide-glutathione versus MAN-glutathione conjugates were lower in urine of CYP2E1-null mice than in that of wild-type animals. Exhalation of MAN-derived organic volatiles (primarily parent MAN) was 12- and 42-fold greater in female and male CYP2E1-null mice than in wild-type mice, respectively. Additionally, exhalation of CO2 derived from metabolism of MAN via the CYP2E1 pathway was 3- to 5-fold greater in wild-type than in CYP2E1-null animals. Although these data indicate that CYP2E1 is the principal enzyme responsible for the oxidative metabolism of MAN, other cytochrome P-450 enzymes may be involved. Assessment of MAN metabolism in CYP2E1-null mice pretreated with 1-aminobenzotriazole (CYP inhibitor) resulted in a further decrease in oxidative metabolites of MAN. Comparison of the tissue concentrations of MAN-derived radioactivity in mouse tissues revealed that MAN-derived radioactivity is generally higher in wild-type > CYP2E1-null mice > CYP2E1-null mice pretreated with 1-aminobenzotriazole, suggesting a direct relationship between MAN oxidative metabolism and the half-life of MAN and/or its metabolites in various tissues. It is therefore concluded that MAN oxidative metabolites such as the epoxide intermediate have greater reactivity than parent MAN. (+info)