Mouse lethal activity of a HEp-2 vacuolation factor, cereulide, produced by Bacillus cereus isolated from vomiting-type food poisoning

The HEp-2 vacuolation factor (or cereulide) produced by Bacillus cereus isolated from vomiting-type food poisoning, which is supposed to induce emesis, was found to give mouse and suncus lethality after intravenous and intraperitoneal administration. The emetic activity of the factor was also found to be resistant to heating at 121 degrees C for 15 min, exposure to pH 2 and 11, and to digestion with proteolytic enzymes such as pepsin and trypsin. These findings suggest that the cereulide produced by B. cereus is stable in the digestive tracts, induce emesis, and show lethal activity leading to cellular damage.     

The rice culture filtrate of Bacillus cereus isolated from emetic-type food poisoning causes mitochondrial swelling in a HEp-2 cell

Rice culture filtrates of Bacillus cereus SA-50, an emetic-type strain, produced a toxin which caused cytoplasmic vacuole formation in HEp-2 and HeLa cells. Electron microscopic observation revealed that the apparent vacuoles in HEp-2 seen under a light microscope were actually swollen mitochondria. The oxygen consumption of HEp-2 cells was accelerated by the addition of the rice culture filtrate as was measured with a polarographic oxymeter; a respiratory control ratio was 1.0 for control cells, while 1.4 for ones with the filtrates. The culture filtrates showed a similar effect on the isolated mouse liver mitochondria; respiratory control ratios for the mitochondria with and without the filtrates were 3.6 and 1.0, respectively. The affecting manner of the culture filtrates on the oxygen consumption of mitochondria was similar to that of 2,4-dinitrophenol, suggesting that the culture filtrate contains a toxin acting as an uncoupler of oxidative phosphorylation in mitochondria. It is likely that the culture filtrates containing the emetic toxin of B. cereus causes mitochondrial swelling with a close relationship to the uncoupling of the oxidative phosphorylation of mitochondria.     

Climate change and the incidence of food poisoning in England and Wales

A study was undertaken to determine the susceptibility or resistance of 9 outbred experimental or commercial poultry lines to Salmonella enteritidis PT4. Young chicks were inoculated either intramuscularly or orally just after hatching. After intramuscular challenge the lines could be divided into susceptible lines (LD 50% < or = 10(2) Salmonella per animal), intermediate lines (LD 50% about 10(4) Salmonella) and resistant lines (LD 50% > 10(5) Salmonella). The results obtained after oral challenge confirmed these 3 groups for both mortality rates and the probability of the presence of salmonellae in the spleen and liver. There was no difference between lines concerning caecal carriage.     

Effects of nisin and temperature on survival, growth, and enterotoxin production characteristics of psychrotrophic Bacillus cereus in beef gravy

The presence of psychrotrophic enterotoxigenic Bacillus cereus in ready-to-serve meats and meat products that have not been subjected to sterilization treatment is a public health concern. A study was undertaken to determine the survival, growth, and diarrheal enterotoxin production characteristics of four strains of psychrotrophic B. cereus in brain heart infusion (BHI) broth and beef gravy as affected by temperature and supplementation with nisin. A portion of unheated vegetative cells from 24-h BHI broth cultures was sensitive to nisin as evidenced by an inability to form colonies on BHI agar containing 10 micrograms of nisin/ml. Heat-stressed cells exhibited increased sensitivity to nisin. At concentrations as low as 1 microgram/ml, nisin was lethal to B. cereus, the effect being more pronounced in BHI broth than in beef gravy. The inhibitory effect of nisin (1 microgram/ml) was greater on vegetative cells than on spores inoculated into beef gravy and was more pronounced at 8 degrees C than at 15 degrees C. Nisin, at a concentration of 5 or 50 micrograms/ml, inhibited growth in gravy inoculated with vegetative cells and stored at 8 or 15 degrees C, respectively, for 14 days. Growth of vegetative cells and spores of B. cereus after an initial period of inhibition is attributed to loss of activity of nisin. One of two test strains produced diarrheal enterotoxin in gravy stored at 8 or 15 degrees C within 9 or 3 days, respectively. Enterotoxin production was inhibited in gravy supplemented with 1 microgram of nisin/ml and stored at 8 degrees C for 14 days; 5 micrograms of nisin/ml was required for inhibition at 15 degrees C. Enterotoxin was not detected in gravy in which less than 5.85 log10 CFU of B. cereus/ml had grown. Results indicate that as little as 1 microgram of nisin/ml may be effective in inhibiting or retarding growth of and diarrheal enterotoxin production by vegetative cells and spores of psychrotrophic B. cereus in beef gravy at 8 degrees C, a temperature exceeding that recommended for storage or for most unpasteurized, ready-to-serve meat products.     

Germination, growth, and sporulation of Bacillus thuringiensis subsp. israelensis in excreted food vacuoles of the protozoan Tetrahymena pyriformis

Spores of Bacillus thuringiensis subsp. israelensis and their toxic crystals are bioencapsulated in the protozoan Tetrahymena pyriformis, in which the toxin remains stable. Each T. pyriformis cell concentrates the spores and crystals in its food vacuoles, thus delivering them to mosquito larvae, which rapidly die. Vacuoles containing undigested material are later excreted from the cells. The fate of spores and toxin inside the food vacuoles was determined at various times after excretion by phase-contrast and electron microscopy as well as by viable-cell counting. Excreted food vacuoles gradually aggregated, and vegetative growth of B. thuringiensis subsp. israelensis was observed after 7 h as filaments that stemmed from the aggregates. The outgrown cells sporulated between 27 and 42 h. The spore multiplication values in this system are low compared to those obtained in carcasses of B. thuringiensis subsp. israelensis-killed larvae and pupae, but this bioencapsulation represents a new possible mode of B. thuringiensis subsp. israelensis recycling in nontarget organisms.     

Iodine intake and the pattern of thyroid disorders: a comparative epidemiological study of thyroid abnormalities in the elderly in Iceland and in Jutland, Denmark

Gastroesophageal reflux (GOR) is often a self-limiting condition but nevertheless is a common cause of morbidity in childhood. Studies of adult patients with hiatus hernias and GOR have suggested that there is an increased incidence of dental erosion in these individuals. The aim of this study was to investigate the relationship between dental erosion and GOR in children. Fifty-three children aged 2 to 16 yr (mean 4.9 yr) with moderate to severe GOR, defined by pH monitoring, were examined for dental erosion. A questionnaire investigating dietary habits, other relevant medical conditions, and erosion risk factors was also completed. Results showed that the prevalence of dental erosion was low, when compared with the UK National Survey, with only 9 (17%) children showing any signs of erosion, and of these only one had erosion involving dentine. These results suggest that dental erosion may not be as great a problem in children with GOR as it is in adults. It may be that refluxing is limited to the oesophagus, and further work is needed to investigate those children that positively reflux into the mouth.     

Evaluation, modelling and optimization of the cleaning process of contaminated plastic food refillables

In this study several types of bottle materials (glass, PET (polyethylene terephthalate), PC (polycarbonate), HDPE (high density polyethylene), PP (polypropylene) and PVC (polyvinyl chloride)) were evaluated in order to be used as food refillables, comparing the residual chemical contamination after classical caustic washing. Bottles were contaminated with model chemicals (chloroxylenol and d-limonene) and caustic washed with varied process parameters using a simulated laboratory-scale washing procedure. After washing, the chemical-contaminated bottles were filled with water and stored for 28 days at 37 degrees C. The concentrations of the model chemicals in the water after storage were taken as a measure of chemical contamination. The influence of the cleaning parameters (temperature, caustic and commercial additive concentration) was studied using response surface methodology. Washing temperature showed a significant influence on the removal of absorbed chemicals from surfaces compared with the effect of the caustic and especially the additive concentration. Optimization of caustic cleaning for the cleaning process in question led to better cleaning effectiveness, although none of the different washing conditions were able to remove all absorbed chemicals out of the polymeric resins. Commercially available plastic refillables (PET and PC) showed the best chemical rinsability. Glass bottles, however, had in every case the best rinsing characteristics.     

Nonaqueous capillary electrophoresis--its applicability in the analysis of food, pharmaceuticals and biological fluids

The use of nonaqueous electrophoresis media for the application of capillary electrophoresis in the analysis of food, pharmaceuticals and biological fluids is reviewed. Some of the applications are discussed in detail and the benefits of using nonaqueous media in these cases are outlined. Three new applications within pharmaceutical analyses are presented. In these methods either a simple sample pretreatment by dilution with methanol (determination of chlorhexidine in a cream) or selective on-line capillary electrophoresis mass spectrometry (methods for identification of seizure drugs or opium alkaloids) are used. The choice of organic solvents and electrolytes for nonaqueous capillary electrophoresis are discussed. Furthermore, validation data obtained using capillary electrophoresis based on the nonaqueous principle are listed and discussed.     

Of sick turkeys, kwashiorkor, malaria, perinatal mortality, heroin addicts and food poisoning: research on the influence of aflatoxins on child health in the tropics

Similarities between the geographical and climatic prevalences of kwashiorkor and of exposure to dietary aflatoxins, and between the biochemical, metabolic and immunological derangements in kwashiorkor and those in animals exposed to aflatoxins, prompted investigation of the associations between kwashiorkor and aflatoxins. Studies in Africa in the 1980s indicated a role for these toxins in the pathogenesis of the disease. Paediatric cases of kwashiorkor are less prone to severe Plasmodium falciparum malaria than normal children. In mice infected with P. berghei, aflatoxin exposure inhibits parasite growth and ameliorates morbidity. Aflatoxins occur in < or = 40% of samples of breast milk from tropical Africa, usually as low concentrations of the relatively non-toxic derivatives of aflatoxin B1 (AFB1) but sometimes as high concentrations of the very toxic AFB1. This could explain kwashiorkor in breast-fed babies. Aflatoxin exposure occurs in > or = 30% of pregnancies in tropical Africa and the toxins are often in cord blood, sometimes at extremely high concentrations. Aflatoxins are now incriminated in neonatal jaundice and there is circumstantial evidence that they cause perinatal death and reduced birthweight. Aflatoxin-induced immunosuppresion may explain the aggressive behaviour of HIV infection in Africa. There are similarities between observations on HIV cases in Africa and those on heroin addicts in Europe, where 'street' heroin is frequently contaminated with aflatoxin. Aflatoxins were found in 20% of random urine samples from heroin addicts in the U.K. and the Netherlands. Aflatoxins have also been incriminated in episodes of food poisoning which have been associated with serious morbidity and mortality, particularly among young children.     

Canine monocytic ehrlichiosis: a retrospective study of 100 cases, and an epidemiological investigation of prognostic indicators for the disease

One hundred cases of monocytic ehrlichiosis diagnosed in Israeli dogs were confirmed by the presence of anti-Ehrlichia canis indirect immunofluorescent antibody titres greater than 1:40. The disease occurred in all age groups and there was no sex predilection. German shepherd dogs were significantly over-represented whereas crossbreed dogs were significantly under-represented (P > 0.0005). The most common clinical signs were depression, lethargy, lymphadenomegaly, fever, anorexia, panting, pale mucous membranes and bleeding, of which epistaxis was most common. Thrombocytopenia, anaemia (mainly normocytic normochromic) and lymphopenia were the predominant haematological findings. Forty-nine of the 100 cases were followed up for a year. Thirty-two dogs survived and 17 died. A Cox proportional hazards regression model was used to examine the effect of host, environmental, and haematological prognostic factors on survival. It was concluded that severe anaemia, severe leucopenia, pancytopenia, a tendency to bleed (especially epistaxis) and being a German shepherd dog were important indicators of poor survival in cases of monocytic ehrlichiosis in dogs.     

Type I, Type II, and other types of errors in pattern analysis.

C. J. Krauskopf (1991) is to be commended for calling attention to the fact that pattern analysis is subject not only to Type I errors but also Type II errors, which were not even mentioned by A. B. Silverstein (1982). There are, however, a number of points on which the authors still differ. Most notably, Krauskopf's recommendation not only fails to solve the multiple-comparisons problem, it exacerbates that problem. Other possibilities are considered, including the possibility that the assumption on which pattern analysis is based, clinical meaningfulness, is itself an error. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of the Gen-Probe PACE 2 assay for the detection of asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees

BACKGROUND: The LET and Gen-Probe PACE 2 assay are used to screen male arrestees for evidence of infection with chlamydia and gonorrhea in the intake/booking area of the Jefferson Parish Correctional Center. GOAL OF THIS STUDY: To determine the accuracy of the Gen-Probe PACE 2 assay for the detection of asymptomatic infection with Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees. STUDY DESIGN: From December 1993 to March 1994, 196 arrestees younger than 22 years were screened with the Gen-Probe PACE 2 assay and McCoy shell vial culture for Chlamydia trachomatis. From April to October 1994, 444 arrestees of all ages were screened with the Gen-Probe PACE 2 assay and standard culture for Neisseria gonorrhoeae. The sensitivity, specificity, and predictive values of the Gen-Probe PACE 2 assay, compared with culture, were calculated with 95% confidence intervals. RESULTS: The Gen-Probe PACE 2 assay compared with culture had a sensitivity, specificity, and positive predictive value for Chlamydia trachomatis of 84%, 99%, and 93% and for Neisseria gonorrhoeae of 54%, 99.5%, and 78%. CONCLUSION: The Gen-Probe PACE 2 assay is useful for screening young males in this jail setting and is more accurate for detecting Chlamydia trachomatis compared with Neisseria gonorrhoeae.     

Evaluation of a practice-based ambulatory program in food animal medicine, surgery, and herd health management

OBJECTIVE: To assess the educational value of a practice-based ambulatory program used at a school of veterinary medicine. DESIGN: Retrospective cohort study. SAMPLE POPULATION: Graduates of US veterinary medical schools between 1987 and 1994. PROCEDURE: Phase I involved use of interviews and focus groups to assist in development of the questionnaire used in phase II, a retrospective cohort study. The pretested questionnaire was sent to a study population consisting of all graduates of the University of Wisconsin-Madison, School of Veterinary Medicine, between 1987 and 1994 as well as a control group who were randomly selected from the 1994 AVMA list of veterinarians. Control-group veterinarians were matched on the basis of professional activity, region, and year of graduation. RESULTS: 728 of 1,067 veterinarians completed the questionnaire in phase II of the study (response rate, 68%). The practice-based ambulatory program at the University of Wisconsin-Madison compared favorably with university-based ambulatory programs in volume of experiences and perceived educational quality. Regardless of rotation type, female students were significantly less likely to observe or perform 12 specific clinical procedures and were significantly less likely to rate instructional quality as excellent or very good, compared with male students. CLINICAL IMPLICATIONS: Practice-based ambulatory rotations can be a good alternative to existing university-based ambulatory rotations. Implementation of these programs should emphasize performance of procedures while striving to ensure participation of female students.     

Molecular composition of two different batches of urofollitropin: analysis by immunofluorimetric assay, radioligand receptor assay and in vitro bioassay

A multi-institutional randomized trial of alfacalcidol (1 alpha hydroxyvitamin D3) was performed to determine the therapeutic effect of alfacalcidol in patients with refractory myelodysplastic anaemias. Twenty-three evaluable patients were randomized to receive either a single daily oral dose of 6 micrograms of alfacalcidol or only supportive care as a control. Treatment was continued, whenever possible, for a period of 6 months. Response was assessed by weekly blood counts, clinical course and repeated marrow examinations. No significant difference was noted between the alfacalcidol and control groups. Three of the 13 patients in the alfacalcidol group, and two of the 10 patients in the control group, suffered a progression of their disease. One patient with refractory anaemia showed a good response to alfacalcidol in all three haematopoietic cell lineages; the response, however, could not be maintained, because discontinuation of the drug resulted in a worsening of pancytopenia which was refractory to a second course of alfacalcidol therapy. Hypercalcaemia was the major toxic side-effect of alfacalcidol therapy. The results indicate that alfacalcidol therapy, when used alone, does not induce a beneficial effect in patients with refractory myelodysplastic anaemias.     

Patients' and therapists' shared and unique views of the therapeutic alliance: An investigation using confirmatory factor analysis in a nested design.

Analyzed large general factor found in measures of the therapeutic alliance by use of confirmatory factor analysis (CFA) in a nested design. Ratings by 38 therapists and their 144 patients on the California Psychotherapy Alliance Scales (CALPAS), the Revised Penn Helping Alliance Questionnaire (HAQ-R), and the Working Alliance Inventory (WAI) were adjusted for therapist effects. A set of models for S and therapist ratings was tested with CFA, and a 3-factor model was confirmed, x–2(4)?=? 7.19, p> .13; GFI?=?.98; RMSR?=?.02; CFI?=?1.0. A shared-view factor (best represented by HAQ-R) accounted for 44% of patients' and 27% of therapists' variance. Unique factors accounted for 56% of therapists' and 43% of Ss' variance. S views split between HAQ and WAI factors; The WAI factor was most expressive of therapist views. (PsycINFO Database Record (c) 2010 APA, all rights reserved)