Mode-coupling study on the dynamics of hydrophobic hydration II: Aqueous solutions of benzene and rare gases.

The dynamic properties of both the solute and solvent of the aqueous solution of benzene, xenon and neon are calculated by the mode-coupling theory for molecular liquids based on the interaction-site model. The B-coefficients of the reorientational relaxation and the translational diffusion of the solvent are evaluated from their dependence on the concentration of the solute, and the reorientational relaxation time of water within the hydration shell is estimated based on the two-state model. The reorientational relaxation times of water in the bulk and within the hydration shell, that of solute, and the translational diffusion coefficients of solute and solvent, are calculated at 0-30 degrees C. The temperature dependence of these dynamic properties is in qualitative agreement with that of NMR experiment reported by Nakahara et al. (M. Nakahara, C. Wakai, Y. Yoshimoto and N. Matubayasi, J. Phys. Chem., 1996, 100, 1345-1349, ref. 36), although the agreement of the absolute values is not so good. The B-coefficients of the reorientational relaxation times for benzene, xenon and neon solution are correlated with the hydration number and the partial molar volume of the solute. The proportionality with the latter is better than that with the former. These results support the mechanism that the retardation of the mobility of water is caused by the cavity formation of the solute, as previously suggested by us (T. Yamaguchi, T. Matsuoka and S. Koda, J. Chem. Phys., 2004, 120, 7590-7601, ref. 34), rather than the conventional one that the rigid hydration structure formed around the hydrophobic solute reduces the mobility of water.

Polychlorinated dibenzo-p-dioxin and dibenzofuran concentrations in serum samples of workers at intermittently burning municipal waste incinerators in Japan.

OBJECTIVES: To find whether or not incinerator workers employed at intermittently burning municipal incineration plants are exposed to high concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). METHODS: 20 Workers employed at three municipal waste incineration plants (incinerator workers) and 20 controls were studied. The previous job, dietary, smoking, and body weight and height were obtained from a questionnaire survey. Concentrations of PCDDs and PCDFs were measured in serum samples of the workers and the deposited dust of the plants. The influence of occupational exposure on concentrations of PCDDs and PCDFs in serum samples was examined by multiple regression analysis. RESULTS: Dust analysis showed that dominant constituents were octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) among the PCDDs, and 1,2,3,4,6,7,8-heptachlorodibenzofuran (HpCDF) and octachlorodibenzofuran (OCDF) among the PCDFs. The toxicity equivalents (TEQs) of summed PCDDs and PCDFs in the deposited dust were 0.91, 33, and 11 ng TEQ/g, respectively, for plants I, II, and III. The means of TEQ in serum samples of summed PCDDs and PCDFs in the incinerator workers and controls were 22.8 and 16.4 pg TEQ/g lipid for area I, 29.4 and 19.3 pg TEQ/g lipid for area II, and 22.8 and 24.9 pg TEQ/g lipid for area III, which were almost the same as for the general population of Japan. No significant differences in the TEQ of PCDDs and TEQ of PCDDs and PCDDs were found between the incinerator workers and the controls. However, the TEQ of PCDFs was significantly higher among the incinerator workers in areas I and II, and the 1,2,3,4,6,7,8-HpCDF concentration was also significantly higher for all three areas. When the occupational exposure index for each constituent of PCDDs and PCDFs was defined as the product of the duration of employment at the incineration plant and the concentration of the constituent in the deposited dust, multiple regression analysis showed that the concentrations of HxCDF, HpCDF, and TEQ of PCDFs in serum samples increased with the occupational exposure index. The multiple regression analysis also suggested that significant factors affecting the concentrations in serum samples were area for HxCDD, age for TCDD, PeCDD, PeCDF, TEQ of PCDDs, TEQ of PCDFs, and TEQ of summed PCDDs and PCDFs, and BMI for HxCDD, HpCDD, and OCDD. CONCLUSION: This study showed that incinerator workers employed at intermittently burning incineration plants were not necessarily exposed to high concentrations of PCDDs and PCDFs. However, the increases in the concentrations in serum of HxCDF, HpCDF and TEQ of PCDFs with the occupational exposure index suggest that the incinerator workers had inhaled dust containing PCDDs and PCDFs during their work.

Polychlorinated dibenzo-p-dioxin and dibenzofuran concentrations in the serum samples of workers at continuously burning municipal waste incinerators in Japan.

OBJECTIVES: To find whether concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in serum increased in workers at municipal incinerators that burn continuously. METHODS: 30 Workers employed at three municipal waste incineration plants (incinerator workers) and 30 control workers were studied. The incinerator workers had worn dust masks or airline masks during the periodic repair work inside the incinerators. Previous job, dietary habit, smoking habit, distance from residence to the incineration plant, and body weight and height were obtained from a questionnaire survey. Concentrations of PCDDs/PCDFs were measured in the serum of the workers and the dust deposited in the plants. The influence of various factors on serum concentrations of PCDDs/PCDFs was examined by multiple regression analysis. RESULTS: Dust analysis showed the greatest amount of octachlorodibenzo-p-dioxin (OCDD), followed by 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD), 1,2,3,4,6,7,8-heptachlorodibenzofuran (HpCDF), and octachlorodibenzofuran (OCDF). The toxicity equivalents (TEQs) of PCDDs and PCDFs in the deposited dust were 4.8, 1.0, and 6.4 ng TEQs/g, respectively, for plants A, B, and C. The mean serum TEQs of PCDDs and PCDFs in the incinerator workers and control workers were 19.2 and 22.9 pg TEQs/g lipid, respectively, for area A, 28.8 and 24.5 pg TEQs/g lipid for area B, and 23.4 and 23.6 pg TEQs/g lipid for area C. No significant differences were found between the incinerator workers and the controls for TEQs of PCDDs and PCDFs separately, and TEQs of PCDDs and PCDFs together. However, the serum 1,2,3,4,6,7,8-HpCDF concentration was significantly higher in the incinerator workers than in the controls for all the three areas. When the exposure index to 1,2,3,4,6,7,8-HpCDF is defined as the product of the concentration of 1,2,3,4,6,7,8-HpCDF in the deposited dust and duration of employment, the concentration of 1,2,3,4,6,7,8-HpCDF in serum increased as the exposure index increased. Multivariate analysis suggested that the serum concentration of HpCDF increased with duration of employment at the incineration plants and OCDF increased with employment of > or = 21 years. The other significant variables (p < 0.01 or p < 0.001) were area for hexachlorodibenzo-p-dioxin (HxCDD) and tetrachlorodibenzofuran (TCDF), Brinkman index for HpCDD, and body mass index (BMI) for tetrachlorodibenzo-p-dioxin (TCDD), HpCDD, and TEQs of PCDDs. CONCLUSION: The serum TEQs of PCDDs and PCDFs was not significantly higher among the incinerator workers, but the serum concentration of 1,2,3,4,6,7,8-HpCDF was. This suggests that the incinerator workers had inhaled dust containing PCDDs and PCDFs while working in plants equipped with incinerators that burn continuously.

[Analyses of work-relatedness of health problems among truck drivers by questionnaire survey].

In order to estimate occupational risk factors for health problems among truck drivers, a questionnaire survey of working conditions, job content in truck transportation, subjective symptoms and present illnesses was carried out among 541 truck transportation workers in 1997. The valid response rate was 85.7%, and 134 local truck drivers, 199 long-distance truck drivers and 71 clerical workers were analyzed. First, to examine occupational risk factors and health problems among the three groups, the authors analyzed working conditions, job content in truck transportation, subjective symptoms and present illnesses. Second, to estimate the work-relatedness of health problems among local truck drivers and long-distance truck drivers, logistic regression analyses were conducted, and odds ratios and 95% confidence intervals were computed. The prevalence rates of working factors affecting health problems of truck drivers were significantly higher than those of clerical workers in the items on irregular shift work, working environment, working posture, handling heavy materials, job stress due to overloading and long working time and limited time off. The prevalence rates for subjective symptoms (ringing in the ears, neck pain and low back pain) and present illnesses (hypertension, ulcers in the digestive tract, back injuries, whiplash injuries and hemorrhoids) among truck drivers were significantly higher than those of clerical workers. In logistic regression analyses, many work-related items except age, BMI and smoking habit showed significantly higher odds ratios for subjective symptoms and present illnesses of truck drivers. Odds ratios for hypertension, heart diseases and related subjective symptoms among local truck drivers were significantly increased by job career, twisting posture, vibration and driving stress. Odds ratios for gastro-duodenal diseases and related subjective symptoms were significantly increased by narrow working space, sleeping in the truck, driving distance, squatting posture and driving stress. Odds ratios for ringing in the ears among local truck drivers were significantly increased by job career, long working time, narrow working space, sleeping in the truck and driving stress. Odds ratios for musculo-skeletal diseases and related subjective symptoms were significantly increased by overwork, vibration, narrow working space, sitting posture and shortage of recess. Odds ratios for fatigue symptoms were significantly increased by the shortage of recess, vibration and driving stress. In order to cope with the health problems of truck drivers, it is recommended that working conditions and work loads for among truck drivers as described above be improved.

[Characteristics of pulmonary tuberculosis patients by mode of detection--comparison of patients detected between 1993-94 with those detected between 1986-88].

In a previous study it was concluded that pulmonary tuberculosis (TB) patients who were detected at a hospital, excluding those detected by mass screening (group A), should be classified into three distinct groups. Namely some patients were detected only after the onset of TB symptoms (group B), with the others being treated for other diseases before being diagnosed as having TB (group C). In group C, some patients were detected because of manifesting additional symptoms related to TB such as cough (group C-1), while the remaining patients were detected by chance while being examined for other diseases (group C-2). Four groups respectively had specific characteristics which differentiated each other. The aim of this study is to elucidate changes of proportion and characteristics of group C compared to the former results. Pulmonary TB patients, who were registered between 1993 and 1994, in the area served by Kochi Prefectural Chuo Health Center (N = 332) were compared with those registered between 1986 and 1988 in the area. The results were as follows. 1) The proportion of group C was significantly higher in the period of 1993-94 than during 1986-88. The proportion of elderly people in group C was higher in the period of 1993-1994 than in 1986-88. The proportion of group C is projected to continue increasing as the proportion of elderly among the population increases. 2) The proportion of smear positive cases by sputum was lower in group C-2 than in group B and group C-1. The proportion of either inactive TB or non TB cases was estimated to be higher in group C-2 than in group B and group C-1. 3) In group C-1, the proportion of bacillus positive cases was higher in the period of 1993-94 than 1986-88. The elongation of the interval between the onset of symptoms and diagnosis (total delay) was related to the severity of bacillus finding.

Nitric oxide (NO)-releasing pathway of FK409 in the presence of sulfhydryl-bearing compounds.

PURPOSE: We have recently reported that degradation of FK409 with generation of NO is spontaneous and is accelerated in the presence of sulfhydryl-bearing compounds, such as L-cysteine (Cys) and glutathione (GSH). The purpose of the present study is to investigate the NO-releasing pathway of FK409 in the presence of sulfhydryl-bearing compounds. METHODS: The degradation process of FK409 in the presence of Cys or GSH was investigated by means of 1H-nuclear magnetic resonance (NMR) spectroscopy and high-performance liquid chromatography (HPLC). RESULTS: The degradation of FK409 in the presence of Cys was dependent on concentration of Cys, and showed pH-dependency, accelerating with an increase in pH. The 1H-NMR spectra of FK409 with Cys suggested that time-dependent elimination of the hydrogen atom at the alpha-position of the nitro moiety (5-position) was accelerated by Cys in weakly alkaline solution. Cys and GSH were transformed readily, concomitant with FK409 degradation, to give their oxidized forms and probably S-nitrosothiols. CONCLUSION: The effect of sulfhydryl-bearing compounds on FK409 degradation is due to the acceleration of deprotonation of the hydrogen atom at the 5-position by thiolate anion as well as hydroxyl ion. Sulfhydryl-bearing compounds reacted with the released NO resulting in formation of disulfides via intermediate S-nitrosothiols.

Acceleration of nitric oxide (NO) release from FK409, a spontaneous NO releaser, in the presence of sulfhydryl-bearing compounds.

PURPOSE: Recently, we have reported that FK409 spontaneously releases nitric oxide (NO) in solution. In the present study, the influence of L-cysteine (Cys) and glutathione (GSH), which are typical sulfhydryl group-bearing compounds, on NO release from FK409 and biological action of FK409 was examined. METHODS: We evaluated the effects of Cys and GSH on NO release from FK409 by nitrite analysis or detection with a chemiiluminesence analyzer. In a biological study, the influence of Cys on inhibition of rat platelet aggregation of FK409 was investigated. In addition, the above mentioned characteristics of FK409 were compared with those of isosorbide dinitrate (ISDN). RESULTS: FK409 decomposed spontaneously with generation of nitrite in solution. Both Cys and GSH accelerated decomposition of FK409 and nitrite generation from FK409 in a concentration-dependent manner. When the NO levels in the headspace of FK409 solutions (0.5 mM) reached equilibrium with and without 25 mM Cys, the constant rate for NO release from FK409 in the presence of Cys was 13 times larger than that in the absence of Cys. In biological study, FK409 (100 microM) showed 56 and 90% inhibition of rat platelet aggregation in the absence and presence of 10 mM Cys, respectively, whereas ISDN (100 microM) showed 10 and 23% inhibition, respectively. CONCLUSIONS: Decomposition of FK409 with generation of NO is spontaneous, and is accelerated in the presence of sulfhydryl group-bearing compounds, thereby potentiating the biological action of FK409.

[An epidemiological study on low back pain and occupational risk factors among clinical nurses].

Recently medical services and nursing system are being reformed due to high medical costs and shortage of clinical nurses. The shortage of clinical nurses influences not only their working conditions but also their own health problems. In European countries and the United States, low back pain (LBP) has been reported to be one of the most common and costly health problems among clinical nurses. To estimate the occupational risk factors of LBP among nurses, a questionnaire survey of LBP and occupational risk factors was carried out in 1987 on 947 clinical nurses and as well as on 300 female clerical workers of three local governments. First, to examine the prevalence and the magnitude of the problem, we analyzed several kinds of prevalence rates of LBP and its characteristics among nurses and clerical workers. Second, a case-control study was conducted to investigate the relationship between LBP and occupational risk factors. In analyzing occupational risk factors of LBP, odds ratios, age adjusted odds ratios and 95% confidence intervals were computed. Finally, to estimate simultaneously the effect of multiple risk factors of LBP and to confirm univariate age adjusted odds ratio analyses, several multivariate analyses were performed. Point, period (a month), and lifetime prevalence rates of LBP and prevalence rate of severe LBP among clinical nurses were significantly higher than those of clerical workers (p less than 0.05-0.001, respectively). Demographic and occupational items, such as being an assistant nurse (as opposed to a registered nurse), and working in certain departments (internal medicine, orthopedic surgery, neurosurgery, psychiatry, tuberculosis ward) showed significantly higher odds ratios for LBP (p less than 0.05-0.001, for all). Many items pertaining to working conditions connected with shift work, hospitalized conditions of patients, taking breaks and holidays, working postures, weight of patients and equipment lifting and moving, working environments and so on had significantly elevated age adjusted odds ratios (p less than 0.05-0.001, for all). Intensity of work loads estimated subjectively such as 'caring for patients who are in bed', 'supporting patients when transporting and bathing them', 'preparing drugs and injections, and treating', 'observing and monitoring patients' conditions', 'instructing and explaining procedure to patients and their family' and so on also had significantly elevated age adjusted odds ratios (p less than 0.05-0.001, for all). Moreover, many items on the problems connected with working life and interpersonal relationships showed significantly higher age adjusted odds ratios (p less than 0.05-0.001). In multivariate analyses, independent variables which made a significant contribution to the model were similar to the items which had significantly elevated age adjusted odds ratios.(ABSTRACT TRUNCATED AT 400 WORDS)

Low-energy collision-induced dissociation of protonated polyamino alcohol derivatives of peptides and N-terminal blocked peptides.

This investigation reports the low-energy collision-induced dissociation of the protonated molecules of polyamino alcohols, formed by chemical reduction of synthetic peptides and N-terminal blocked peptides, in order to evaluate its potential for peptide sequence determination. The --CH2--NH-- cleavage with charge retention on the N-terminus was prominent, and the entire sequence of ions produced in this manner was observed. Some of the sequence ions arising from --CH2--NH-- cleavage accompanied by migration of two hydrogens, and --NH--C alpha H-- cleavage with charge retention on the C-terminus, also occurred prominently. In addition, a great number of internal fragment ions were produced in relatively high abundance; these provided supplementary sequence information and were, in some cases, critical in determining the sequence. The usefulness of this method was exemplified by its application to the sequence determination of bacterial lipopeptides.

Antitumour activity of purified arabinogalactan-peptidoglycan complex of the cell wall skeleton of Rhodococcus lentifragmentus.

Antitumour activity of arabinogalactan peptidoglycan (AP) complex (peptidoglycan and arabinogalactan liberated by an acid or alkaline treatment from Rhodococcus lentifragmentus AN-115 cell wall skeleton) was examined in mice and compared with that of the cell wall skeleton. The growth of syngeneic fibrosarcoma Meth A cells after implantation in BALB/c mice was significantly suppressed by AP complex, and also regressed after intratumoral injection of AP complex on days 1, 4 and 7 after tumour implantation. Although the activity of peptidoglycan was less than that of AP complex, peptidoglycan also showed both tumour-suppressive and regressive activities. Arabinogalactan did not show antitumour activity. It is interesting that peptidoglycan has an important role in the effect against tumours.

Nuclear ribonucleoprotein immune complexes in pericardial fluid of a patient with mixed connective tissue disease.

We performed immunopathologic studies of the pericarditis present in a patient with mixed connective tissue disease. A large number of nuclear RNP (nRNP) immune complexes (ICs) were found in the pericardial fluid, but not in the serum. The pericardial small vessels had no deposits of IgG. These results suggest that locally formed nRNP ICs were closely associated with the pathogenesis of pericarditis in this patient.

[Postoperative chemotherapy of perforating appendicitis in children; with special reference to latamoxef therapy].

We employed latamoxef (LMOX) as antibiotic therapy subsequent to the performance of appendectomies in children. Fifteen patients, consisting of 8 cases of catarrhal appendicitis and 7 cases of gangrenous appendicitis, were administered LMOX at 50 mg/kg/day, while 13 patients with peritonitis due to a perforated appendix were treated with a dosage of 90 mg/kg/day. Both of these dosages were administered in 3 equally-divided doses, as one shot intravenous injections. All of the cases of catarrhal and gangrenous appendicitis showed good, steady recovery after the surgery, and there were no instances of complications. With regard to the 13 cases of perforating appendicitis, a clinical efficacy of at least "good" was obtained in 12 patients, for an efficacy rate of 92.3%. In addition, bacteriologically, 35 out of 36 strains that were isolated initially could no longer be detected after the LMOX therapy, indicating an eradication rate of 97.2%. Complications consisted of 1 case of dehiscence of the wound, and 1 case of adhesive ileus. Comparison of the values of the laboratory tests before and after the LMOX therapy revealed no development of abnormalities. Moreover, with regard to side effects, with the exception of 1 case of transient diarrhea, there were no side effects which presented clinical problems. It was found that the causative microbes involved in these cases of appendicitis--especially in the perforative appendicitis cases--were Gram-negative bacilli such as E. coli, and an anaerobic bacterium, B. fragilis.(ABSTRACT TRUNCATED AT 250 WORDS)