Prevalence of the main food-borne pathogens in retail food under the national food surveillance system in Japan.

The National Food Surveillance System in Japan was formed in 1998 to monitor the contamination of retail foods with bacterial pathogens. Approximately 2000-3000 samples were tested annually, and the data from food categories that had more than 400 samples collected during 1998-2008 were analysed. With regard to meat, the frequency of positive samples for Salmonella in chicken for raw consumption and ground chicken was 12.7% and 33.5%, respectively. Moreover, Shiga toxin-producing Escherichia coli (STEC) O157 was found in ground meat, organ meat and processed meat, although at a low frequency (0.1%). The prevalence of Campylobacter jejuni/coli was 13.3% and 20.9% in chicken for raw consumption and ground chicken, respectively. In vegetables and fruit, Salmonella was detected in cucumber, lettuce, sprout and tomato samples at a frequency of around 0.1-0.2%. With regard to seafood, Salmonella was found in 0.5% of oysters for raw consumption. Seafood was not contaminated with STEC O157 or Shigella. Serotype Infantis was the most frequently detected serotype of Salmonella in seafood, followed by the serotypes Typhimurium, Schwarzengrund and Manhattan. In ground chicken, 72.2% of the strains were identified as the serotype Infantis. E. coli, as an indicator of food hygiene, was detected in all food categories. The results show the prevalence of the above-mentioned pathogens in the retail food supplied in Japan; further, they indicate that consumption of raw food carries the risk of contracting food-borne infections.

Effect of temperature on VFA's and biogas production in anaerobic solubilization of food waste.

The effectiveness of methane fermentation treatment used in food waste processing is currently limited by solubilization and acidogenesis. In efforts to improve the treatment process, this study examined the effects of temperature on solubilization and acidogenesis. The solubilization rate of food waste, which was based on suspended solid removal, was 47.5%, 62.2%, 70.0%, 72.7%, 56.1% and 45.9% at 15 degrees C, 25 degrees C, 35 degrees C, 45 degrees C, 55 degrees C and 65 degrees C, respectively. Solubilization rate was accelerated from the middle to late experimental periods under mesophilic (35 degrees C and 45 degrees C) conditions. In contrast, overall solubilization rate was significantly lower under thermophilic (55 degrees C and 65 degrees C) conditions than under mesophilic conditions, although solubilization occurred rapidly in the early experimental period. The production of biogas was high under mesophilic conditions of 35 degrees C and 45 degrees C, at 64.7 and 62.7mL/g-VS, respectively, while it was scarce under thermophilic conditions. Solubilization of food waste was accelerated under both mesophilic and thermophilic conditions; however, solubilization rate was observed to be particularly high under mesophilic conditions, and a shortening of the hydraulic retention time is expected under thermophilic conditions.

Verrucotoxin, a stonefish venom, modulates calcium channel activity in guinea-pig ventricular myocytes.

BACKGROUND AND PURPOSE: Stonefish (Synanceia genus) are commonly found in shallow waters of the Pacific and Indian Oceans. The venom of stonefish is stored in the dorsal fine spines and contains a proteinaceous toxin, verrucotoxin (VTX). The stings produced by the spines induce intense pain, respiratory weakness, damage to the cardiovascular system, convulsions and paralysis, sometimes leading to death. Although there are many studies on VTX, the mechanism(s) underlying the VTX-mediated cardiotoxicity is not yet fully understood. The aim of this study was to investigate the modulation of ion channels in cardiac tissue by VTX. EXPERIMENTAL APPROACH: The effects of VTX on changes in the voltage or current in guinea-pig ventricular myocytes were investigated using a patch clamp method. KEY RESULTS: VTX (10 microg ml(-1)) prolonged the action potential duration by 2.5-fold. VTX increased L-type Ca(2+) currents (I (Ca(L))) in a concentration-dependent manner with a EC(50) value of 7 microg ml(-1) and a maximum increase of 3.1-fold. The non-selective beta-adrenoceptor antagonist, propranolol (1 microM) and the selective beta(1)-adrenoceptor antagonist, CGP20712A (10 microM) each abolished the effect of VTX (100 microg ml(-1)) on I (Ca(L)). Furthermore, the protein kinase A (PKA) antagonists H-89 (10 microM) and Rp-8-Br-cAMPS (30 microM) inhibited the effect of VTX on I (Ca(L)). CONCLUSIONS AND IMPLICATIONS: VTX modulates Ca(2+) channel activity through the beta-adrenoceptor-cAMP-PKA pathway.

Salmonella prevalence and total microbial and spore populations in spices imported to Japan.

A total of 259 samples of 40 types of spices were tested for Salmonella prevalence and total microbial and spore populations. Salmonella enterica serotypes Weltevreden and Senftenberg were isolated from a black- and red-pepper sample, respectively. Because Salmonella was not detected by the most-probable-number method, it indicated that at least one cell of the microorganism was present in 25 g of sample. The mean aerobic bacterial count was greater than 5.39 log CFU/g in turmeric, garam masala, curry powder, and paprika. The mean bacterial spore counts were greater than 4.33 log CFU/g in turmeric and curry powder. The mean aerobic bacterial count in the two Salmonella-isolated samples was 6.93 log CFU/g. These results indicate that spices can be a source of contamination in the products where they are used as ingredients, and methods to reduce the microbial load in spices should be used.

Increased lymphoid MxA expression in acute asthma exacerbation in children.

BACKGROUND: Although the association between acute asthma exacerbation and viral infection has been well documented, virus identification rates vary. It has recently been reported that the expression of MxA protein in lymphocytes, inducible by type I interferons, can serve as a sensitive marker for viral infection in the host. The objective was to determine the contribution of viral infection to precipitation of asthma attacks in children. METHODS: We studied 186 asthmatic children, aged 0-12 years, over a 1-year period to evaluate MxA protein levels in peripheral blood lymphocytes by using a flow cytometric analysis in whole blood. RESULTS: Of all the subjects, 80 (47%) exhibited significantly elevated levels of MxA expression in lymphocytes, presumably indicating the states of viral infection. The association of viral infections with acute asthma exacerbation seemed to be marked in younger children: enhanced MxA expression was seen in 73.3% of infants (aged 0-1 year), 49.5% of toddlers (aged 2-5 years), and 26% of schoolchildren (aged 6-12 years). Seasonal changes in the frequency of viral infection associated with deterioration were also observed. CONCLUSIONS: Flow cytometric assay of MxA protein expression in whole blood appears to be an easy and useful method to evaluate viral infections in acute asthma exacerbation.

CD30 expression on circulating memory CD4+ T cells as a Th2-dominated situation in patients with atopic dermatitis.

Th2 clones have been reported to express CD30 preferentially, but whether T cells producing Th2-type cytokines may favor CD30 expression in the in vivo state remains unknown. We investigated the expression of CD30 on circulating T cells in atopic dermatitis (AD) as a Th2-dominated disorder. Peripheral blood mononuclear cells were prepared from 51 AD patients and 14 nonatopic controls, and their phenotypes were analyzed with flow cytometry. Cytokine production by stimulated CD4+ T cells was also assessed by the single-cell-staining method. Flow cytometric analysis clearly revealed that CD30+ T cells were identifiable in the blood of AD patients with greater frequency compared to controls. The important finding was that CD30 expression was restricted to a small but substantial population of memory (CD45RO+) CD4+ T cells, but not CD8+ ones. In AD patients, it was demonstrated that the percentages of CD30+ cells within CD45RO+ CD4+ T cells correlated well with the disease severity, serum IgE levels, peripheral eosinophil counts, and tendency toward Th2-dominant cytokine pattern as determined by the ratio of interleukin-4 to interferon-gamma production. This study suggests that CD30 expression in circulating T cells might serve as an in vivo marker for the Th2-dominated condition.

Differential expression of the chemokine receptors by the Th1- and Th2-type effector populations within circulating CD4+ T cells.

The in vitro studies have proposed that human Th1 cells favor expression of CXCR3 or CCR5, whereas Th2 cells favor CCR3 and CCR4. In this study, the in vivo relevance of expression of these chemokine receptors on Th cells was investigated in patients with atopic dermatitis (AD) as the Th2-dominated disorder and nonatopic normal individuals. Flow-cytometric analysis using monoclonal antibodies against CXCR3, CCR5, CCR3, and CCR4 disclosed that a substantial proportion of memory (CD45RO+) CD4+ T cells in the blood of AD and normal patients expressed CXCR3, CCR5, or CCR4, but expression of CCR3 on these cells was negligible. Stimulation studies combined with intracellular cytokine staining revealed that the cells capable of producing Th2 cytokines, such as interleukin-4 (IL-4), IL-5, and IL-13, were restricted to the CCR4-expressing population within memory CD4+ T cells. Concerning Th1 cytokine production, interferon-gamma (IFN-gamma)-producing cells resided exclusively in CXCR3-expressing memory CD4+ T cells, although IFN-gamma production was found in both memory CD4+ T cells with and without CCR5 expression. We observed that CCR4-expressing memory CD4+ T cells in the blood were more increased in AD patients as compared with normal patients, whereas CXCR3-expressing memory CD4+ T cells were present in a lower frequency in AD than seen in normal patients. These results suggest that CXCR3 and CCR4, but not CCR5 or CCR3, appear to serve as the useful markers for identification of circulating Th1 and Th2 effector populations.

Collaborative evaluation of detection methods for Escherichia coli O157:H7 from radish sprouts and ground beef.

For the evaluation of plating and immunological methods applicable to the detection of Escherichia coli O157:H7 from ground beef and radish sprouts, a collaborative study was conducted. It focused on a comparison of the efficiency of the plating and immunological methods using various plating agars and immuno-kits in combination with enrichment in modified E. coli broth supplemented with novobiocin (mEC + n), and using immunomagnetic separation. The plating media tested were sorbitol MacConkey agar (SMAC), SMAC supplemented with cefixime (0.05 mg/l) and potassium tellurite (2.5 mg/l) (CT-SMAC), and agars containing beta-glucuronidase substrates such as BCM O157 and CHROMagar O157. The immuno-kits used were Now E. coli, Path-Stick O157, VIP, EHEC-Tek ELISA System and Rapiblot E. coli O157. The 20 participating laboratories attempted to detect E. coli O157:H7 in 25 g chilled and frozen samples of ground beef uninoculated and inoculated with E. coli O157:H7 at levels of 138.9 and 23.9 cfu/25 g, and in 25 g chilled and frozen samples of radish sprouts uninoculated and inoculated at levels of 20.4 and 1.7 cfu/25 g. E. coli O157:H7 was recovered well from ground beef by all of the methods except direct plating with SMAC. For radish sprouts, the IMS-plating methods with CT-SMAC, BCM O157 and CHROMagar O157 were most efficient at detecting E. coli O157:H7 in more than 90% of the chilled samples inoculated at the level of 20.4 cfu/25 g. All the methods were less sensitive when applied to similar levels of E. coli O157:H7 in radish sprouts (20.4 cfu/25 g) compared with ground beef (23.9 cfu/25 g) especially if the sprouts were frozen. The sensitivity of the immuno-kits appeared to be similar to the IMS-plating methods, but the specificity was lower. Based on the results, we recommend the IMS-plating method using CT-SMAC and agars containing beta-glucuronidase substrate in combination with static enrichment incubation in mEC + n at 42 degrees C.

Occurrence of a methyl derivative of saxitoxin in Bangladeshi freshwater puffers.

A new component of paralytic shellfish poison was isolated from a Bangladeshi freshwater puffer Tetraodon cutcutia. Its structure was deduced to be carbamoyl-N-methylsaxitoxin based on electrospray ionization mass spectrometry, [1H] NMR, and conversion experiments.

Three cases of primary lung cancer undetected by an annual checkup.

An annual check by chest roentgenogram is very important for the early detection of lung cancer. We present three cases of primary lung cancer which were not detected by the double check system or previous examination. The three patients visited our hospital for evaluation of an ill-defined opacity in the upper lobe of the lung. In the three cases, no abnormality had been reported in the previous year's annual chest X-ray, and we concurred in the decisions. The correct diagnoses of the three cases were well or poorly differentiated adenocarcinoma, and were still amenable for surgical therapy. A poorly defined tumor in this region is very difficult to detect because of superimposed opacities of other anatomical structures. When a questionable shadow in this region is found but without the typical radiological features of lung cancer, it is important to search for indirect indications of adenocarcinoma. These may include fibrotic changes and absence of inflammation. In our cases, the increased number of normal-size bronchi penetrating the ill-defined tumor, seem to have diagnostic significance.

Occurrence of paralytic shellfish poisons in Thai freshwater puffers.

Screening tests were carried out on the toxicity of freshwater puffers Tetraodon leiurus complex and Tetraodon suvatii collected from Udonthani province, north-eastern Thailand. Toxicity was highest in the liver and varied according to the location and season of fish catch. Fish which were reared in tap water for 3 months reduced the toxicity substantially. Partial purification was achieved by an ultrafiltration technique. Toxin components were consequently identified by high-performance liquid chromatography. It was found that toxins separated from the eggs, liver, skin and muscle of these puffers were composed of saxitoxin, neosaxitoxin and decarbamoylsaxitoxin.

Amino acid requirements for the growth and enterotoxin production by Staphylococcus aureus in chemically defined media.

The production of enterotoxins A, B, and C by five strains of Staphylococcus aureus was studied in a series of defined media, each differing from the complete defined medium in the lack of one amino acid. Valine was required for growth; arginine and cystine for growth and enterotoxin production. Omission of individual amino acid affected in different ways the yields of the toxins produced.

Occurrence of paralytic shellfish poison in Bangladeshi freshwater puffers.

Two species of freshwater puffer fish, Tetraodon cutcutia and Chelonodon patoca, collected from several locations in Bangladesh, showed lethal potency in mice ranging from 2.0 to 40.0 MU/g tissue as paralytic shellfish poison. In both species, toxicity of the skin was generally higher than the other tissues examined (muscle, liver and ovary). Water-soluble toxins from T. cutcutia were partially purified by activated charcoal treatment followed by column chromatographies using Bio-Gel P-2 and Bio-Rex 70. Analyses by cellulose acetate membrane electrophoresis and high-performance liquid chromatography with fluorometric detection demonstrated that the toxins were composed of saxitoxin, decarbamoylsaxitoxin, gonyautoxins 2 and 3, decarbamoylgonyautoxins 2 and 3, and three unidentified components which are possibly related to paralytic shellfish poison.

Two new isomers of domoic acid from a red alga, Chondria armata.

Isodomoic acids G and H, two new isomers of the neurotoxin domoic acid, along with isodomoic acids A, B, E and F, were isolated from a red alga, Chondria armata, collected at the southern tip of Kyushu Island. The structures of two of these were deduced to be (E, E) and (Z, E) isomers of 2-carboxy-4-(5-carboxy-l-methyl-2-hexenylidene)-3-pyrro- lidineacetic acid, based on electrospray ionization mass and [1H]nuclear magnetic resonance spectral analyses including [1H-1H]correlation spectroscopy and nuclear Overhauser effect correlation spectroscopy.

[Study of cockroach allergy in asthmatic children. The positive rates and antigenicity of cockroach allergen].

The specific IgE antibodies to 4 species of cockroach were measured in sera from 51 asthmatic children 6 to 16 years old by RAST and CAP system. Positive rates of RAST to Periplaneta fuliginosa, Blattela germanica, Periplaneta americana and Periplaneta japonica were 17.6%, 29.4%, 19.6% and 15.7%, respectively and those of CAP system to Periplaneta fuliginosa and Blattela germanica were 15.7%, respectively. Among those with positive RAST to 4 species of cockroach there were significant correlations. Significant correlations were observed also between the RAST titer for the whole bodies and feces of Periplaneta fuliginosa and Blattela germanica and immunoblotting analysis of sera obtained from two cockroach-positive patients revealed common sensitive fraction between whole body and feces. Immediate bronchial response was detected by bronchial provocation test. RAST inhibition study indicated no cross-reacting allergenicity between cockroach and mite. Collectively, cockroach is one of important inhalent allergens in asthmatic children.

[Airborne Japanese cedar allergens studied by immunoblotting technique using anti-Cry j I monoclonal antibody--comparison with actual pollen counts and effect of wind speed and directions].

We collected airborne particles of Japanese cedar pollen with Burkard's sampling tape in Toyama from February to April 1992. The tape was cut into two pieces in parallel to time axis. The one of piece of the tapes was stained with glycerin-jerry and stained pollens were counted with a microscope. The other piece was treated according to the immunoblotting technique. The airborne pollen allergens, reacting with anti-Cry j I monoclonal antibody, were stained as blue spots. The spots were classified by diameter into two groups, large spots (> 50 microns) and small spots (< 50 microns). There were significant correlations found between the airborne Cry j I allergen spots (in large and small) and actual pollen counts obtained with the Burkard's sampler and the Durham's sampler (r = 0.729, 0.586 in large spots and r = 0.676, 0.489 in small spots, p < 0.001). The counts of small spots stayed in high level even in April when actual pollen counts decreased. We concluded that this discrepancy was caused by allergenic crushed cedar pollen particles staying floating longer than actual pollens. Secondly we set a gauge of wind speed and direction at the same point as the samplers. The actual pollen counts and large spots counts were significantly larger in the wind (SE wind in Toyama city) from cedar trees blooming area than other areas. However small spots counts did not differ significantly according to wind directions. Wind speed did not effect on actual pollen counts, large spots counts and small spots count.

[Mass-screenings for osteoporosis using computed X-ray densitometry (CXD): in a mobile unit].

The early diagnosis and treatment of osteoporosis is considered to be important for the prevention of fractures which often cause elderly to become bed-ridden. Computed X-ray densitometry (CXD), a method to measure bone mineral content in the metacarpus II utilizing a simple X-ray image, has been used for mass-screening of osteoporosis, because of its utility and reliability. However, due to its requiring adequate X-ray equipment, this method is often unsuitable for use in small facilities in a remote mountain areas. The use of CXD for osteoporosis screening, was attempted in a mobile unit for tuberculosis screening, by our public health center. The results showed that it is possible to use CXD in combination with a mobile unit, correcting the obtained values according to the radiographic conditions. With this set-up, CXD was used for mass-screening of osteoporosis in a total of 1150 subjects living in mountainous areas of Yoshino-gun, Nara prefecture, and CXD was found to be convenient and effective for mass-screening. The use of CXD in a mobile chest X-ray unit can be expected to be useful for mass-screening of osteoporosis especially in remote mountainous areas having inadequate X-ray equipment.

Properties of hemagglutinins newly separated from toxic phytoplankton.

Unique substances of the hemagglutinating activity were separated from unialgal cultures of the toxic phytoflagellates, Chattonella marina and Gymnodinium sp. Molecular masses of the substances were estimated to be 14,000 in Chattonella and 15,000 in Gymnodinium. These two substances contained phosphorus, hexose (galactose) and glycerol in the following molar ratios; 1.00:1.18:1.24 (Chattonella) and 1.00:1.07:1.10 (Gymnodinium). Hemagglutinating titres using rabbit red blood cells were inferred to be 25,000 in both preparations. In the presence of Chattonella hemagglutinin (0.10-0.50 microM), the growth of C. marina in Provasoli's ES media was little affected during 24 h of incubation, whereas a marked suppression took place in growth in Gymnodinium sp. (50% inhibition, 0.12 microM) or the diatom Nitzschia closterium (0.17 microM). On the other hand, Gymnodinium hemagglutinin inhibited the growth of the three species of phytoplankton. A 50% inhibition occurred at 0.12 microM in C. marina, at 0.22 microM in N. closterium or at 0.50 microM in Gymnodinium sp.

[Bronchial hypersensitivity and development of bronchial asthma in children with atopic dermatitis].

Using histamine inhalation tests, we followed changes in bronchial hypersensitivity in 48 children with atopic dermatitis (AD) who were nonasthmatic on their initial visit. Twenty-three of these subjects became asthmatic during the follow-up period. The respiratory thresholds to histamine RT-Hist) of children with AD were widely distributed, ranging from 156 to more than 5000 micrograms/ml. There was a statistical difference in RT-Hist, as those who became asthmatic showed lower levels (< or = 625 micrograms/ml) at 2-6 yr of age. The percentage of peripheral eosinophil counts and IgE level was significantly elevated in those who became asthmatic. Subjects who developed asthma were more likely to have had positive D.p. RAST when they were less than 2 yr of age. The development of asthma in children with AD showed no significant relationship with family history of bronchial asthma.