Studies on health hazards among cooks providing school lunch service. Report 2. An analysis of factors associated with the development of health hazards

The previous report revealed that the musculoskeletal symptoms of cooks are related to their working conditions, but the cause and effect relationship was not clarified. In the present report, the relationship between some causative factors and the health hazards is analyzed epidemiologically. The subjects were chosen from the cooks mentioned in the previous report. The results are as follows: A clear relationship was not observed between age and health hazards. A dose-response relationship was observed between the cumulative duration of cooking work and the subjective symptoms. An antecedent-consequent relationship was also shown between the cooking work and the health hazards. Another dose-response relationship was observed between the amount of cooking work and the subjective symptoms. The frequency of "carrying heavy objects" assigned as a cause of development of the hazards, especially of low-back pain, increased in accordance with the number of meals served in each kitchen. It was observed that the improvement of cooking equipment enabled the incidence of symptoms to decline, but the elevation of working speed due to mechanization could still be hazardous. As a result of the physical examination, a similarity was observed between the cooking work and the clinical findings in comparison with ticket-vending machine operators. It is concluded that these results demonstrate a cause and effect relationship between cooking work and the development of health hazards.     

Effect of latanoprost/timolol and dorzolamide/tiomolol on intraocular pressure after phacoemulsification surgery

AIM: To evalaute the effect of fixed-combination latanoprost 0.005%/timolol maleate 0.5% and dorzolamide hydrochloride 2%/timolol maleate 0.5% on postoperative intraocular pressure after phacoemulsification cataract surgery. METHODS: This study is a prospective, randomized, double-masked and placebo-controlled. The study included 90 eyes of 90 patients which were scheduled to have phacoemulsification surgery. Patients were randomly assigned preoperatively to 1 of 3 groups (30 eyes of 30 patients). Two hour before surgery, the patients received one drop latanoprost/timolol (group 1), dorzolamide/timolol (group 2) and placebo (group 3, control group). The IOPs were measured at preoperative and postoperative 4, 8, and 24 hours. RESULTS: The preoperative mean intraocular pressure was not statistically significant between both drug groups and control group. In group 1 and 2, the postoperative mean IOP [group1: (14.03±3.15)mmHg and group 2: (14.16±4.43)mmHg] at 24 hours were significantly lower than the control group [(16.93±3.70)mmHg, (P<0.05)]. In addition, the postoperative mean IOP of group 1 [(14.90±3.69)mmHg] at 8 hours was significantly lower than the control group [(17.70±3.89)mmHg, (P<0.05)], but there was no significant difference between group 2 [(16.16±5.23)mmHg] and control group at 8 hours (P>0.05). CONCLUSION: When compared with placebo, the use of preoperative fixed combination of latanoprost/ timolol and dorzolamide/timolol is an effective method for preventing intraocular pressure elevation in 24 hours after phacoemulsification surgery, but did not completely prevent IOP spikes.     

Preliminary study on the development of a system dynamics model: the case of EVAHEART

The Japanese medical device industry’s stagnation over the years can be attributed to the uncertainty related to device development. The purpose of this study is to identify the major factors that impact development. We studied the ventricular assist device EVAHEART through interviews with the persons involved and created a development model using system dynamics. There are at least six stages in the device development process, including interactions with academia and the government. Through a simulation and comparison to Novacor, it was determined that the satisfaction of academia leads to government action in the subsequent measures. Our trial simulation of EVAHEART suggests that it has the potential to clarify unclear relationships in the development of devices.     

Reducing Peg-IFN doses causes later virologic response or no response in HCV genotype 1 patients treated with Peg-IFN alfa-2b plus ribavirin

Background

The timing to the first undetectable hepatitis C virus (HCV) RNA level is strongly associated with sustained virologic response in pegylated interferon (Peg-IFN) plus ribavirin combination therapy for patients with chronic hepatitis C (CH-C) with genotype 1. This study was conducted to clarify the impact of drug exposure to Peg-IFN on the timing of HCV RNA negativity in Peg-IFN plus ribavirin combination therapy for CH-C patients with genotype 1.

Methods

A total of 1409 patients treated with Peg-IFN alfa-2b plus ribavirin were enrolled and classified into four categories according to the Peg-IFN dosage. Furthermore, 100 patients were extracted from each Peg-IFN dosage category to adjust for characteristic factors, using the propensity score method.

Results

Peg-IFN exposure was dose-dependently associated with the timing of HCV RNA negativity (p????0.001). The HCV RNA negative rate at week 4 decreased from 12% with a Peg-IFN dose of >1.5???g/kg/week to 1?C3% with a dose of <1.5???g/kg/week (p????0.001), and at week 12 the rate had decreased from 44% with a dose of ??1.2???g/kg/week to 18% with a dose of <1.2???g/kg/week (p?=?0.001). Treatment failure (patients without a 1-log decrease of HCV RNA at week 4 or a 2-log decrease of HCV RNA at week 12, or positive at week 24) was found in 54?C66% of patients given <1.2???g/kg/week (p????0.001), and these patients accounted for 64% of the non-responders.

Conclusions

The timing of HCV RNA negativity depends significantly on the Peg-IFN dose. Reducing the Peg-IFN dose can induce a later virologic response or non-response in HCV genotype 1 patients treated with Peg-IFN plus ribavirin.     

Obesity is associated with biliary tract cancer mortality and incidence: A pooled analysis of 21 cohort studies in the Asia Cohort Consortium

Body fatness is considered a probable risk factor for biliary tract cancer (BTC), whereas cholelithiasis is an established factor. Nevertheless, although obesity is an established risk factor for cholelithiasis, previous studies of the association of body mass index (BMI) and BTC did not take the effect of cholelithiasis fully into account. To better understand the effect of BMI on BTC, we conducted a pooled analysis using population-based cohort studies in Asians. In total, 905 530 subjects from 21 cohort studies participating in the Asia Cohort Consortium were included. BMI was categorized into four groups: underweight (<18.5 kg/m²); normal (18.5-22.9 kg/m²); overweight (23-24.9 kg/m²); and obese (25+ kg/m²). The association between BMI and BTC incidence and mortality was assessed using hazard ratios (HR) and 95% confidence intervals (CIs) by Cox regression models with shared frailty. Mediation analysis was used to decompose the association into a direct and an indirect (mediated) effect. Compared to normal BMI, high BMI was associated with BTC mortality (HR 1.19 [CI 1.02-1.38] for males, HR 1.30 [1.14-1.49] for females). Cholelithiasis had significant interaction with BMI on BTC risk. BMI was associated with BTC risk directly and through cholelithiasis in females, whereas the association was unclear in males. When cholelithiasis was present, BMI was not associated with BTC death in either males or females. BMI was associated with BTC death among females without cholelithiasis. This study suggests BMI is associated with BTC mortality in Asians. Cholelithiasis appears to contribute to the association; and moreover, obesity appears to increase BTC risk without cholelithiasis.     

Genesis of hexavalent chromium from natural sources in soil and groundwater

Naturally occurring Cr(VI) has recently been reported in ground and surface waters. Rock strata rich in Cr(III)-bearing minerals, in particular chromite, are universally found in these areas that occur near convergent plate margins. Here we report experiments demonstrating accelerated dissolution of chromite and subsequent oxidation of Cr(III) to aqueous Cr(VI) in the presence of birnessite, a common manganese mineral, explaining the generation of Cr(VI) by a Cr(III)-bearing mineral considered geochemically inert. Our results demonstrate that Cr(III) within ultramafic- and serpentinite-derived soils/sediments can be oxidized and dissolved through natural processes, leading to hazardous levels of aqueous Cr(VI) in surface and groundwater.