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.

Within-shift variability of short-term exposure to organic solvent in indoor workplaces

This study examined the degree of within-shift variability of short-term exposure concentrations for workers exposed to organic solvents in indoor workplaces. For this purpose, 117 exposure data sets of 15-minute time-weighted average (15-min TWA) and those of 60-min TWA were collected from 53 workers employed in the offset printing, gravure printing, screen printing, machine control board production, fiber-reinforced plastic production, hard metal production, electrical parts production, and chemical synthesizing industries. Data analysis showed that the tenth, fiftieth, and ninetieth percentiles of the geometric standard deviations of 15-min TWA values [GSD(15m)] were 1.4, 2.3, and 4.5, respectively; and those of GSD(60m) were 1.2, 1.7, and 3.4, respectively. Based on an assumption of lognormal exposure distribution, the maximum values of 15-min TWA (the 98.4th percentile) were estimated to be 4.3, 36, and 650 times as high as the minimum one (the 1.6th percentile) for the low, middle, and high exposure variabilities, respectively; and to be 2.0, 4.3, and 8.2 times the 8-hour TWA value, respectively. Consequently, when the 8-hour TWA exceeds 0.23 times (1/4.3) the short-term exposure limit value, the high short-term exposure condition should be evaluated. The maximum values of 60-min TWA (the 93.8th percentile) were estimated to be 1.8, 5.1 and 43 times as high as the minimum one, respectively; and to be 1.3, 2.0, and 3.1 times the 8-hour TWA value, respectively. The relationship between production factors and within-shift exposure variability was also examined. The intermittent solvent use group had significantly higher median values of GSD(15m) and GSD(60m) than the continuous group. The mobile pollutant source group had a significantly higher median value of GSD(60m) than the stationary group.

A historical cohort mortality study of workers exposed to asbestos in a refitting shipyard

To investigate the risks of developing asbestos-related diseases we conducted a historical cohort mortality study on 249 ship repair workers (90 laggers and 159 boiler repairers) in a single U.S. Navy shipyard in Japan. We successfully identified the vital status of 87 (96.7%) laggers and 150 (94.3%) boiler repairers, and, of these, 49 (56.3%) and 65 (43.3%) died, respectively, during the follow-up period from 1947 till the end of 1996. Our in-person interviews with some of the subjects clarified that asbestos exposure was considered to be substantially high in the 1950-60s, decreased thereafter gradually but remained till 1979 in the shipyard. The laggers, who had handled asbestos materials directly, showed a significantly elevated SMR of 2.75 (95% C.I.: 1.08-6.48) for lung cancer. The risk developing the disease was greater in the laggers after a 20-year latency (SMR = 3.42). Pancreatic cancer yielded a greater SMR than unity (7.78, 90% C.I.: 2.07-25.19) in a longer working years group. Four laggers died from asbestosis. The boiler repairers, who had many chances for secondary exposure to asbestos and a few for direct exposure, showed no elevation of the SMR of lung cancer overall, but there was a borderline statistically significant SMR of 2.41 (90% C.I.: 1.05-5.45) in a longer working years group. One boiler repairer died from mesothelioma and four from asbestosis.

[Load on the low back of teachers in kindergartens]

In order to evaluate the load on the low back of teachers in kindergartens, basic activity and working posture were analyzed for four teachers by means of video recording. The trunk inclination angle (TIA) was also measured continuously during full workshifts for 12 kindergarten teachers by means of an inclination monitor. The kindergarten teachers spent 67% of the workshift on activities in contact with children, "indoor group childcare", "indoor free playing", "outdoor childcare", "preparation and clearing away" and "help and care", and did not take a recess during the workshift. They spent 36% of the workshift in three working postures with the load on the low back, "standing bent forward", "squatting" and "kneeling". Cumulative time at a TIA of 20 degrees or more represented 43% of the workshift. The frequency of trunk-lifting from severe bending forward (TIA > 45 degrees) was 95 times/hr on average. A comparison of the kindergarten teachers and nursery teachers in 4-5 year age classes showed that the time distributions of basic activities were generally similar to each other. Although the time distributions of working postures were also similar, time spent "standing bent forward", "squatting" and "kneeling" was longer in the kindergarten teachers than in the nursery teachers. Cumulative time at a TIA of 45 degrees or more was significantly longer in the kindergarten teachers. Although the frequency of trunklifting was not significantly different, the kindergarten teachers tended to lift their trunk more frequently. The present study found that the load on the low back was considerably great in the kindergarten teachers.

[Antimicrobial activity of carbapenem antibiotics against gram-negative bacilli]

Antimicrobial activities of meropenem (MEPM), imipenem (IPM), panipenem (PAPM), ceftazidime (CAZ), cefozopran (CZOP), aztreonam (AZT), norfloxacin (NFLX) and tetracycline (TC) against clinically isolated Gram-negative bacilli [271 strains of Enterobacteriaceae and 242 strains non-fermentative Gram-negative bacteria (NFB)] were investigated. Among carbapenem antibiotics, MEPM showed the lowest MIC90, which activity was about four-hold higher than those of IPM and PAPM. The activity of IPM was equal or slightly superior to that of PAPM. Resistance to IPM (> 16 micrograms/ml) was observed in 3 strains of Enterobacteriaceae (1.1%) and 14 strains of NFB (5.8%). It is conceivable that these strains produce metallo-beta-lactamase. Referring to the correlation among MICs of MEPM, IPM and PAPM, 3 strains in 3 species of Enterobacteriaceae showed cross resistance to carbapenems; while 14 strains of NFB showed cross resistance to MEPM and IPM, 15 strains to MEPM and PAPM, and 29 strains to IPM and PAPM, and all of these strains were Pseudomonas aeruginosa. Fifteen of 29 strains of IPM-resistant and 77 of 92 strains of PAPM-resistant P. aeruginosa were susceptible to MEPM. Thirty-three strains (12%) of the Enterobacteriaceae were resistant to CAZ and AZT (> or = 32 micrograms/ml) and these were considered as ESBL-producing strains.

[Cytokine measurement at a single-cell level to analyze human Th1 and Th2 cells]

Th1 cells, which produce IL-2 and IFN gamma, are responsible for cell-mediated immune responses, and Th2 cells, which produce IL-4 and IL-5, facilitate humoral immune responses. It has been shown that these two types of cells play critical roles in defensive immune responses and in immunopathological disorders such as allergic reactions and autoimmune diseases, and the methods of detecting Th1 and Th2 cells have become more important. A newly developed technique enables intracellular cytokines to be stained and detected on flow cytometry at a single-cell level. To show the existence of human Th1/Th2 cells, naive human CD4+ T cells were differentiated into Th cells in vitro, and Th1/Th2 cells were clearly demonstrated using intracellular IL-4 and IFN gamma staining. IL-4 promoted Th2 differentiation and IL-12 did Th1, as previously reported. Th1 and Th2 cells among human peripheral blood T cell population also can be detected by this technique using double staining for IL-4 and IFN gamma, and the predominance of Th1 cells among peripheral blood T cells were suggested. Measurement of intracellular cytokines is a useful technique, and will be used in the field of clinical laboratory medicine to further clarify the pathophysiology of immunological disorders.

Experimental and clinical evaluation of cisplatin-containing microspheres as intraperitoneal chemotherapy for ovarian cancer

BACKGROUND

We aimed to evaluate the in vitro and in vivo effects of poly [L-lactic acid] microsphere containing cisplatin (CDDP-MS) for intraperitoneal (i.p.) chemotherapy for ovarian cancer.

METHODS

We initially examined the in vitro and in vivo profile of cisplatin release from the CDDP-MS, then this drug delivery system was evaluated in 15 patients.

RESULTS

The in vitro study showed that cisplatin was released constantly over a 3-week period. Rats in the CDDP-MS group had a significantly lower peak serum concentration of platinum compared with rats in the aqueous cisplatin solution (CDDP-S) group; the serum concentration of platinum showed a gradual decline. The ascitic fluid concentration of platinum also gradually decreased in the CDDP-MS group. We treated 15 patients with recurrent ovarian cancer with CDDP-MS containing 200 mg of cisplatin (n = 5) or CDDP-S containing 100 mg of cisplatin (n = 10) administered i.p. The peak serum and ascites concentrations of platinum were lower immediately after administration of CDDP-MS than after administration of CDDP-S, but increased over time in the CDDP-MS group, reflecting the slow-release effect of CDDP-MS. Grade 1 to 2 leukopenia and/or neutropenia occurred in 2 of 5 patients. No thrombocytopenia or renal or neurologic toxicity was observed;

CONCLUSION

These findings indicate that the i.p. administration of CDDP-MS increased the dose intensity of cisplatin and appeared to be safe and effective for the treatment of ovarian cancer.

[A proposed method for evaluating short-term exposure condition]

High short-term exposure to toxic chemicals can occur during a workday, even if the daily average exposure is lower than the permissible exposure limit, because the exposure concentration varies from minute to minute. To protect workers from acute health effects due to high short-term exposure, the Japan Society for Occupational Health recommends that the maximum value for 15-min time-weighted average (15-min TWA) exposure during a workday should not exceed 1.5 times the occupational exposure limit for 8-hr TWA, and the American Conference of Governmental Industrial Hygienists issues the threshold limit value-short-term exposure limit (TLV-STEL), that is a 15-min TWA exposure which should not be exceeded at any time during a workday. A workday (8 hr) consists of thirty two 15-min periods. If the thirty-two 15-min TWAs are measured, the short-term exposure situation can be appropriately evaluated by comparing the highest measured value with the standard value (e.g. TLV-STEL), but such continuous monitoring consumes a lot of cost and time. In this paper, we propose a method for evaluating short-term exposure by using three or more measured values. This evaluation method corresponds to two different types of selection of sampling periods. One is a random selection of three or more 15-min periods among the 32 periods. If this selection is adopted, a comparison between the 98.44 percentile of the within-day distribution of 15-min TWAs and the standard value can be made by using one-sided tolerance factors, KI, KII and KIII, and the exposure situation is classified into four exposure classes at 95% and 50% confidence levels. Another is a random selection among high exposure periods. If this selection is adopted, a comparison between the specific percentile of the distribution and the standard value can be made with modified one-sided tolerance factors, and the exposure class is determined similarly. This method can provide a precise evaluation of exposure, so that it is useful in the industrial hygiene field.

[Sarpogrelate hydrochloride for Raynaud's phenomenon of patients with collagen diseases]

OBJECTIVE

To evaluate clinical efficacy of sarpogrelate hydrochloride (SPG), a novel 5HT2- serotonergic receptor antagonist, for Raynaud's phenomenon associated with collagen diseases.

PATIENTS AND METHODS

Thirty two patients with collagen diseases such as scleroderma, mixed connective tissue disease, systemic lupus erythematosus, Sjögren's syndrome, and rheumatoid arthritis were enrolled. SPG (300mg/day) was administered for 8 weeks. Patients were asked to record the frequency of Raynaud's phenomenon and subjective symptoms in a diary, and evaluations were made in weeks 4 and 8 of treatment. Thermography and determination of whole blood serotonin levels were also conducted in some patients.

RESULTS

The frequency and duration of Raynaud's phenomenon and subjective symptoms such as coldness and pain significantly improved in weeks 4 and 8 compared to the pre-treatment baseline. Thermography showed significantly improvements of skin temperature recovery rate following cold water loading after treatment with SPG. Epigastric distress was reported by 3 patients, but no other adverse reaction or abnormal changes in laboratory tests were observed. Whole blood serotonin levels per platelet increased significantly after treatment with SPG, suggesting that administration of SPG might inhibit activation of the platelets.

CONCLUSION

A global improvement rate ("markedly improved" + " moderately improved") of 66% was obtained and SPG was regarded as safe in 85% of patients and useful or very useful in 82%. SPG is expected to be a useful new therapy for Raynaud's phenomenon in patients with collagen disease.

[ADF/thioredoxin as an indicator of oxidative stress]

Serum ADF was measured in patients with Crush syndrome and various rheumatic diseases by a sensitive sandwich ELISA. Serum ADF level of healthy subjects was highest in 30- to 40-year-olds, and decreased with age. The level was significantly higher in males than females. Crush syndrome patients with an unfavorable prognosis showed markedly high serum ADF level. Serum ADF was significantly increased in patients with SLE, Sjögren's syndrome, and RA. In RA patients, serum ADF was negatively correlated with serum CRP which reflects disease activity. Next, we investigated polymorphisms of Glutathione S-transferase (GST), which is thought to prevent oxidation of lipids and DNA. We have found that the incidence of GSTM1/GSTT1 double null genotypes was significantly increased in SLE patients compared with that in normal subjects. When serum ADF levels were compared among SLE patients, significantly higher ADF was observed in double null patients. Many kinds of oxidative stress are known to attack the immune systems and to bring out inflammation and autoimmunity. The abnormal regulation of ADF system seem to be closely related to such disorders.

Reduction of Escherichia coli O157:H7 populations in soy sauce, a fermented seasoning

We studied five Escherichia coli O157:H7 strains in soy sauce which was incubated at 4, 18, or 30 degrees C after inoculation. The cell numbers of E. coli O157:H7 decreased to an undetectable level (<20 CFU/ml) within 9 days in all the soy sauce samples at 30 degrees C, but did not decrease in the 0.1 M phosphate-buffered saline (pH 7.0) control solution under the same conditions. Soy sauce reduced the cell numbers of bacteria at 18 degrees C to a lesser extent than at 30 degrees C, but to a greater extent than at 4 degrees C. Components of soy sauce such as 10% or 16% NaCl, 5% ethanol, lactic acid, or acetic acid at pH 4.5, sodium benzoate (0.6 g/kg), or p-hydroxybenzoic acid n-butyl ester (0.05 g/liter) caused a reduction of the E. coli O157:H7 population at 30 degrees C, and the anti-E. coli O157:H7 effect of each component was less than that of soy sauce. The fate of E. coli O157:H7 cells in a buffered solution containing various components of soy sauce resembled that in soy sauce at 30 degrees C, which demonstrated the importance of the combination of the soy sauce components for its anti-E coli O157:H7 action.

Induced potential model for muscular contraction mechanism, including two attached states of myosin head

The model for myosin head motion along an actin filament as proposed by Mitsui & Chiba [(1996). J. theor. Biol. 182, 147-159] is here modified so that it can explain the isometric tension and isotonic velocity transients having the same parameter values as the stationary filament sliding. The modified model differs in that a myosin head forms a complex with two actin molecules in an actin filament and has two attached states in the complex instead of three. Thus an incremental step in the myosin head motion is equal to the F-actin monomer repeat (5.46 nm). Muscle properties concerning the stationary filament sliding are calculated with new parameters in a manner similar to that of Mitsui-Chiba, with the results being qualitatively similar to theirs. In studying the transient phenomena, a quantitative expression is given for the potential energy of the myosin head in the complex, and two rate constants are applied to the kinetics of the head. The time course of tension recovery after a quick length change is determined by calculating the statistical distribution of the head in the two attached states, which conforms to experimental observations by Ford et al. [(1977). J. Physiol. 269, 441-515]. The tension variations T1/T0 and T2/T0 calculated with parameters determined from the analysis of stationary filament slidings are in fairly good agreement with the experimental data by Ford et al. The model suggests that a large fluctuation exists in the relative position between the actin and myosin filaments even when the load on a muscle is kept constant. Taking this fluctuation into account explains the characteristics of the isotonic velocity transient observed by Civan & Podolsky.

Effects of variation in exposure to airborne acetone and difference in work load on acetone concentrations in blood, urine, and exhaled air

Using a physiologically based pharmacokinetic (PBPK) model, the effects of variation of exposure concentration of acetone on three biological indicators--acetone concentrations in blood, urine, and exhaled air--were investigated. The effect of the difference in work load was also examined. It was confirmed that the model could be used to estimate acetone concentrations during fluctuating exposure by comparing simulated acetone concentrations with the corresponding values observed in field surveys. By inputting the exposure situations into the PBPK model, the variabilities of the biological indicators were simulated. The variation of acetone exposure was expressed by seven 1-hour time-weighted averages (CEXPs). The arithmetic means of the CEXPS were 200 and 750 ppm. The geometric standard deviations (GSDs) were 1.5, 2.0, and 3.0, representing low, moderate, and high variations, respectively. Work loads were set at 15 and 50 W. Consequently, there were 12 exposure situations. The acetone concentrations in venous blood (CB) and exhaled alveolar air (CA) at 1 minute after the end of the work shift were selected as biological indicators of exposure because they were predicted to decrease rapidly at the end of exposure and become relatively stable after 1 minute. The acetone concentration in urine excreted during the last 2 hours of the work shift (CU) was also used as a biological indicator. Simulation was repeated 100 times with randomly permuting CEXPs for each situation. The mean values of CB, CU, and CA showed almost no variation regardless of the difference in the GSD of CEXPs. The coefficients of variation increased with the GSD of CEXPs but were less than 0.2. Consequently, these variables were acceptable as biological indicators of daily average exposure for the same work load. However, the difference in work load greatly changed the mean values of CB, CU, and CA, thus making it difficult to use these variables as indicators of daily average exposure for different work loads.

Enterohemorrhagic Escherichia coli O157:H7 present in radish sprouts

Using cultivation, immunofluorescence microscopy, and scanning electron microscopy, we demonstrated the presence of viable enterohemorrhagic Escherichia coli O157:H7 not only on the outer surfaces but also in the inner tissues and stomata of cotyledons of radish sprouts grown from seeds experimentally contaminated with the bacterium. HgCl2 treatment of the outer surface of the hypocotyl did not kill the contaminating bacteria, which emphasized the importance of either using seeds free from E. coli O157:H7 in the production of radish sprouts or heating the sprouts before they are eaten.

Changes in work performances in obstructive sleep apnea patients after dental appliance therapy

The effects of dental appliances on work performances of obstructive sleep apnea syndrome (OSAS) is not well examined. This study evaluated the polysomnographic and psychological findings before and after therapy. Nine patients were diagnosed OSAS by nocturnal polysomnography. The psychological batter, was performed from 13:00 to 14:00, which consisted of Uchida-Kraepelin psychodiagnostic test (U-K's test) and Bourdon's cancellation test (Bourdon's test). Approximately 3 months after the treatment, the examinations were performed. Apnea and desaturation index decreased significantly after the therapy. In addition, sleep architecture improved after the therapy compared with that before the therapy. Dysfunction of task performances, such as mean level of work amounts in U-K's test, mean error, mean performance time and mean deviation in Bourdon's test improved after therapy. We conclude that dental appliances therapy is effective not only to apnea but also to work performance in OSAS.

The fate and acute toxicity of aflatoxin B1 in the mastomys and rat

The fate and acute toxicity of aflatoxin B1 (AFB1) were studied in the mastomys (Praomys coucha) and compared with Fischer rats. The experiment regarding the fate of [3H]AFB1 showed that the radioactivity was excreted mainly through the feces, more rapidly in the mastomys than in the rat, regardless of whether [3H]AFB1 was given orally or intravenously. The levels of radioactivity bound to the liver DNA were lower in the mastomys than in the rat, indicating that the levels of AFB1 binding to the macromolecules in the liver were lower in the mastomys. Consistent with such differences in the fate of AFB1 between the two species, the mastomys were far more resistent to the acute effects of AFB1 than were the rats. Oral administration of AFB1 at a dose of 1.0 mg/kg to rats caused marked microscopic changes in the liver, involving hepatic necrosis and proliferation of bile ducts, but at a dose of 4.0 mg/kg to mastomys caused no pathological changes in the liver or kidneys, and at a dose of 10.0 mg/kg caused only glycogen deposition in hepatic cells in a limited area. The observed differences in susceptibility to the toxic effects of AFB1 and in the fate of AFB1 between the two species are in accord with our previous finding that liver cytosol in the mastomys inhibits microsome-mediated AFB1-DNA binding in vitro more strongly than in rat liver.

Juvenile xanthogranuloma occurring in the oral cavity: case report and histopathological findings

Juvenile xanthogranuloma is commonly seen in the dermis, and only very rarely develops in the oral mucosa. Here were report a case that occurred in the anterior palate of a 9-year-old boy. The lesion appeared as a dark red and well-defined nodule measuring 12 x 14 mm. Histologically, it consisted of a proliferation of histiocytes and fibroblastic stroma intermingled with foamy cells. Many lipid droplets without limiting membrane were observed in the cytoplasm under electron microscopy, but no Langerhans' cell granules were observed. The proliferative histiocytes were positive for lysozyme and macrophage HAM56 under immunohistochemical observation, but not for S-100 protein. From these findings, the lesion was diagnosed as juvenile xanthogranuloma. The post-operative course, now amounting to 7 years, has been uneventful.

Prevalence of antibody to Toxoplasma gondii in Hyogo Prefecture, Japan: comparison at a 10-year interval

We have previously surveyed antibody to Toxoplasma gondii among Japanese populations. In this report, we studied the current situation of antibody prevalence and compared it with the situation approximately 10 years before. A total of 1,800 human serum samples were collected at the Central Laboratory of Kobe University Hospital from June through September, 1995, and were examined for Toxoplasma antibody using enzyme-linked immunosorbent assay. The overall prevalence was found to be 16.4% with similar seropositivities in males (16.8%) and females (15.9%). Prevalence of antibody increased with age, reaching 41.0% in males and 59.0% in females at 80 years or more. Comparison with data obtained at the same hospital in 1981 to 1982 indicated that seropositivities at 30-39 years significantly decreased in both males and females. A positivity currently obtained at a certain age group was similar to a positivity previously obtained at the corresponding age group (10 years younger), indicating that the previous age prevalence curve shifted to the current position. A serological survey among stray cats collected in Hyogo Prefecture in 1990-1991 indicated that 44 (19.0%) of 231 cats were positive for Toxoplasma antibody as determined by the latex agglutination test. These results suggested less transmission of Toxoplasma to humans in Hyogo Prefecture at least for the last 10 years comparing with the situation in the past, although the transmission cycle among cats was still active in nature.

Association of a new allele of the TAP2 gene, TAP2*Bky2 (Val577), with susceptibility to Sjögren's syndrome

OBJECTIVE

To investigate the polymorphisms of TAP (transporters associated with antigen processing) genes among patients with primary Sjögren's syndrome (SS) in order to clarify the potential association of the polymorphisms with disease susceptibility.

METHODS

Polymorphisms of the TAP1 and TAP2 genes in 108 Japanese SS patients were determined by analyzing TAP genes using the polymerase chain reaction-single-stranded conformation polymorphism technique.

RESULTS

The allelic frequency of the TAP1 gene was not significantly different between SS patients and normal subjects. In addition to all known TAP2 alleles, a new allele (Bky2), which had a unique substitution at codon 577 (ATG-->GTG: Met-->Val), was identified in both groups. The allelic frequency of Bky2 was significantly higher in SS patients (12.0%) than in normal subjects (5.1%) (P < 0.05). Moreover, a significantly greater frequency of SS-A antibody was found among SS patients with Bky2 (18 of 23; 78%) than among those without Bky2 (33 of 85; 39%) (P = 0.001).

CONCLUSION

The mutation in TAP2 (Val577) may be involved in SS-A autoantibody production and could be a genetic factor that determines susceptibility to SS.

Immunohistochemical study of tumour angiogenesis in oral squamous cell carcinoma

To assess the clinical significance of angiogenesis in oral squamous cell carcinoma (SCC), we examined vessel density immunohistochemically in 44 primary oral SCCs using the JC-70A antibody which reacts specifically with vascular endothelial cells. In addition, the expression of vascular endothelial growth factor (VEGF) and its receptors, KDR, Flt-1 and Flt-4 in oral SCCs was examined in relation to the vessel density and lymph node metastasis. There was no association of vessel density with tumour site, T-category (tumour size), degree of differentiation or cervical lymph node metastasis, except that the vessel density of carcinomas with a well-defined tumour-stromal boundary was higher than that of diffusely invasive carcinomas. The intensity of VEGF expression correlated with lymph node metastasis (P < 0.01), but not with vessel density. The expression of KDR and Flt-1 did not correlate with vessel density and lymph node metastasis. However, the vessel density in Flt-4-positive carcinomas was higher than that in Flt-4-negative carcinomas (P < 0.05), and expression of Flt-4 most significantly correlated with lymph node metastasis (P < 0.001). These results suggest that the expression of VEGF or Flt-4 rather than vessel density may be a predictor of lymph node metastasis in oral SCC.

Potential Hazard of Radish Sprouts as a Vehicle of Escherichia coli O157:H7

We studied the contamination of radish sprouts after exposure to Escherichia coli O157:H7-inoculated water in the laboratory. The edible parts, the cotyledons and hypocotyl, became heavily contaminated with E. coli O157:H7 when they were grown from seeds soaked in E. coli O157:H7-inoculated water. These same parts became contaminated with E. coli O157:H7 when their roots were dipped into E. coli O157:H7-inoculated water. These findings suggest that E. coli O157:H7 contamination in the edible parts of radish sprouts could pose a serious hazard if the seeds or hydroponic water are contaminated with the bacterium.

[Inhibition of 5-fluorouracil-cisplatin-induced stomatitis by oral cryotherapy: use of an ice-bar containing fibrinolysin and deoxyribonuclease combine (Elase)]

Stomatitis caused by a combined chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP) is a serious problem in the course of treatment for patients with oral carcinoma. In the present study, we proposed a form of cryotherapy using an ice-bar containing fibrinolysin and deoxyribonuclease (Elase) to inhibit the stomatitis. The therapeutic effect of the ice-bar cryotherapy was evaluated in 20 patients with oral squamous cell carcinoma who were undergoing 5-FU-CDDP chemotherapy. Nine of the 20 patients were given the ice-bar cryotherapy while the remaining patients were not. As a result, although there was no significant difference between the incidence of stomatitis in the groups with and without the ice-bar cryotherapy, the incidence of severe stomatitis with ulcers and/or eating disturbance in the 11 cases without the ice-bar cryotherapy (90%) was significantly higher than that in the 9 cases with the cryotherapy (44%) (p < 0.05). However, no significant difference in the clinical response rate of the 5-FU-CDDP chemotherapy was observed between the two groups.

Quantitative determination of urinary metabolites of o-dichlorobenzene using a gas chromatograph

o-Dichlorobenzene (o-DCB) is used as an organic solvent, as a chemical intermediate, and as a heat transfer medium. In humans, o-DCB is metabolized to 2,3- and 3,4-dichlorophenols, and 3,4- and 4,5-dichlorocatechols, and these metabolites are eliminated via the kidneys. In this study, we tried to determine the concentrations of urinary 2,3- and 3,4-dichlorophenols using a gas chromatograph (GC). When control urine specimens were spiked at concentrations of 10, 20 and 40 mg/l, the mean recovery rates of 2,3- and 3,4-dichlorophenols were 98.3 to 101.9% (CV = 4.0 to 4.8%) and 100.6 to 105.4% (CV = 2.5 to 7.0%), respectively. Next, urine samples collected from ten male workers exposed to o-DCB were analyzed. The concentrations of urinary 2,3- and 3,4-dichlorophenols determined by the GC method closely agreed with those by the HPLC method, which we had developed in a previous study, and these metabolite concentrations were linearly correlated to the 8-h TWA values of o-DCB in the range of 0.1 to 2.3 ppm. Consequently, the GC method can be used for biological monitoring of o-DCB, though it is necessary that the linear relation is confirmed in a higher range of exposure.