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Biomedical subjects

Shinji Kumagai

Publications and source records attributed to Shinji Kumagai.

17 recordsLinked to original sources

Genotoxic risks to nurses from contamination of the work environment with antineoplastic drugs in Japan.

The aims of the present study were to clarify the work environment contamination by antineoplastic drugs in a hospital ward and to assess the genotoxic risks to nurses who routinely handle antineoplastic drugs in Japan. The exposed group consisted of 19 female nurses who routinely handled antineoplastic drugs. The control group consisted of 18 female nurses who did not handle antineoplastic drugs in the same hospital as the exposed group. The genotoxicity of the 19 antineoplastic drugs used in the hospital ward and 8 wipe samples of the workbench after handling of antineoplastic drugs were measured using the umu assay. Lymphocyte DNA damage (tail length) was measured with alkaline methods of the single cell gel electrophoresis assay (comet assay). Of the 19 antineoplastic drugs, dacarbazine, bleomycin, daunorubicin, doxorubicin, pirarubicin, carboplatin, cisplatin and etoposide induced genotoxicity. Of the 8 sampling d, the umu activity of the wipe sample was positive on 3 d. Contamination of the workbench was found when the nurses handled more drugs than on other days. The medians of the tail length in the comet assay were 8.5 and 5.1 microm, respectively, for the exposed and control groups, with a significant difference (p=0.004 by Mann-Whitney's U-test). In the present study, the nurses of the exposed group were considered to have been exposed to antineoplastic drugs and lymphocyte DNA damage of the exposed group was suggested to be induced by antineoplastic drugs.

Adult↗

[Occupational health of endoscope sterilization workers in medical institutions in Osaka Prefecture].

To clarify the actual condition of endoscope sterilization work and the adverse health effects of disinfectants on personnel, a questionnaire was sent to 173 medical institutions in Osaka Prefecture. Glutaraldehyde (GA), ortho-phtalaldehyde (OPA), and hyperacetic acid were used as disinfectants of endoscopes by 55.5%, 32.4%, and 8.7% of the medical institutions respectively. The kind of disinfectant used had been changed in 57.8% of these institutions during the past five years, and it was confirmed that the use of substitutes for GA, such as OPA and hyperacetic acid, has increased. Personnel in 35.8% of the institutions complained about symptoms during sterilization work. The kind of disinfectant being used when they complained was GA in many cases and OPA in others. A general ventilation system has now been installed in 72.3% of the institutions; local exhaust systems have been installed in fewer, only 23.4%. Protective gloves were used at about half of the institutions, but protective masks and glasses were seldom used. This study shows that the occupational health problems of endoscope sterilization work have not been resolved. Consequently, it is necessary to promote the installation of ventilation systems and the use of protective devices in all institutions. Health education in regard to the handling of disinfectants is also necessary. Because little information is available about the toxic effects of OPA and hyperacetic acid, epidemiological studies must be conducted to clarify the human health effect of these disinfectants.

Acetic Acid↗

[Equipment at the special nursing homes for the elderly: a workplace survey of new nursing homes in Osaka Prefecture].

The number of those who need nursing care and the workers who provide it have been increasing year after year. In April 2000, the public nursing care insurance system was enacted by the Japanese government. After its enaction, care equipment came under scrutiny, but the situation regarding the installation of equipment is not fully understood. In order to understand the present state of care equipment in nursing facilities for the elderly, we conducted a workplace and interview survey. The surveyed facilities were 10 special nursing homes for the elderly in Osaka Prefecture which were established after April 2002. The average number of elderly residents was 79.0, the average value of degree of care was 3.52, and the average number of caregivers was 28.3 per facility. We found all facilities had installed some kinds of bathing equipment: stretcher type, 9 facilities; bath-chair type, 8 facilities. In the facilities with bath-chairs, 6 facilities had special bathtubs, and 6 facilities had general bathtubs. However, all facilities had the working principle that transfer should be done manually, and the equipment for transfer such as a lifts, a transfer and roller board were not be installed. In changing diapers, bed height adjustment was not possible. And the Japanese standard type of wheelchair has a non-detachable armrest, creating a structural barrier when transferring elderly people from a wheelchair to a toilet seat. At all facilities the basis of care was that caregivers should do it manually. In particular, all facilities had only a weak recognition of the risks of transfer. This investigation shows that facilities for the elderly should rethink elderly care based on a reduction of care load and most importantly protection of caregivers' health.

Baths↗

Negative association between serum dioxin level and oxidative DNA damage markers in municipal waste incinerator workers.

OBJECTIVES: To investigate the effect of dioxin on the formation of oxidative DNA damage and urinary mutagenicity, we measured the concentrations of serum dioxins and lymphocytic 8-hydroxydeoxyguanosine (8-OH-dG) in 57 male waste incinerator workers, urinary 8-OH-dG and urinary mutagenicity in 29 male waste incinerator workers. METHODS: Information about the subjects was obtained from a questionnaire. Concentrations of polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), and coplanar-polychlorinated-biphenyl (Co-PCB) in serum samples from the workers were measured with a high-resolution gas chromatograph /high-resolution mass spectrometer. Lymphocytic and urinary 8-OH-dG levels were measured with a high-performance liquid chromatography-electrochemical detector system. The urinary mutagenicity was measured with umu assay. RESULTS: The lymphocytic 8-OH-dG level showed a negative association with the serum dioxin level (total value of TEQ-PCDD, PCDF, and Co-PCB). Urinary 8-OH-dG did not show correlation with serum dioxin level, but showed positive correlation with the smoking index. CONCLUSIONS: With respect to the subjects' serum dioxin level, dioxin did not increase the urinary 8-OH-dG level by oxidative DNA damage, but upregulation of the primary defenses with oxidative damage and/or DNA repair system activity might have occurred.

Adult↗

Polychlorinated dibenzo-p-dioxin and dibenzofuran concentrations in serum samples of workers at an infectious waste incineration plant in Japan.

In 1998-2000, concentrations of summed polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in the exhaust gas of an infectious waste incineration plant were 17-510 ng toxic equivalents (TEQ)/m(3), which reached levels above the Japanese legal limit value of 80 ng TEQ/m(3). The incinerator ceased operation in November 2000. This study was aimed at determining whether the incinerator workers were exposed to high levels of PCDDs and PCDFs. Blood samples of five workers were collected at 1 month and 16 months after the end of the occupational dioxin exposure. For comparison, blood samples were also collected from control subjects. Ash remaining in the incinerator and dust deposited around the conveyer and incinerator areas were collected; TEQ values were 44 and 10 ng TEQ/g, respectively. A month after the end of occupational dioxin exposure, mean TEQ for the workers was 49.1 pg TEQ/g lipid, which was 2.7 times as high as that for the controls. At 16 months, the mean TEQ for the workers decreased to 29.4 pg TEQ/g lipid, which was 1.6 times that for the controls. Ratios of serum level of each congener of PCDDs and PCDFs between 1 and 16 months after exposure were 0.44 to 0.69. This study showed that the serum dioxin levels for the infectious waste incinerator workers were higher than the controls, and the serum dioxin level decreased after the end of the occupational dioxin exposure.

Adult↗

[Load on the low back of care workers in nursing homes for the elderly].

In order to evaluate the load on the low back of care workers in nursing homes for the elderly, basic activities and working postures were analyzed for six care workers using the 30-s snap reading method. The trunk inclination angle (TIA) was also measured continuously using an inclination monitor. The analysis of basic activities showed that 22.5% and 21.1% of the workshift were spent on 'bathing and ablution' and 'meal', respectively, and 9.3%, 8.7% and 8.3% were spent on 'assistance with elimination', 'assistance with moving and repositioning' and 'exchange of bed sheet', respectively. Total of the assistance activity was 43.7% of the workshift. The analysis of working posture showed that 'standing' and 'standing bent forward' accounted for 36.1% and 29.5%, respectively, of the workshift. Total of three postures loading the low back ('standing bent forward', 'squatting', 'kneeling') accounted for 39.0%. The time spent in TIA of 20 degrees or more was 45.7%. The postures loading the low back during 'bathing and ablution', 'exchange of bed sheet' and 'assistance with elimination' account for 68.3%, 58.2% and 49.6%, respectively, which suggests that these activities load the low back of the care workers considerably.

Adult↗

[Health risks of occupational exposure to anticancer (antineoplastic) drugs in health care workers].

In Europe and America, many health care workers have concerns about the risks to their health of handling anticancer drugs. The findings of the risks were reported in the late 1970's, and guidelines for the safe handling of anticancer drugs were established in the 1980's. The conditions of wearing personal protective equipment and of the working environment have improved dramatically as a result of introduction of the guidelines. Furthermore, researches and studies into the health effects of occupational exposure to anticancer drugs have been pursued actively. In Japan, the society of hospital pharmacists established guidelines for the safe handling of anticancer drugs in 1991. Since then, mainly nurses have been concerned about the safe handling of anticancer drugs, but in the medical setting, the present situation surrounding the safe handling of anticancer drugs has hardly changed. In the industrial hygiene field, the safe handling and the occupational exposure to anticancer drugs have been seldom reported and researched. The actual potential hazards to occupational exposure of anticancer drugs have not yet been determined. Nevertheless, the reduction of occupational exposure to anticancer drugs in health care workers has been an important challenge for the industrial hygiene field. In Japan, we need to promote action to spread the use of the appropriate personal protective equipment and the appropriate working environment. We also have to rethink the safe handling of anticancer drugs. We hope that the Japanese government will establish an effective authorized guideline as has been done in Europe and America.

Antineoplastic Agents↗

[Status of noise in small-scale factories having press machines and hearing loss in workers].

A study on noise and hearing loss was conducted in 36 small-scale factories where press machinery is actively used. Noise levels in working environments were measured in 34 factories. Of those measured, two (6%), eight (24%) and 24 (71%) factories were classified into control classes I, II and III, respectively, according to guidelines established for the prevention of noise-related disorders. Furthermore, personal exposure levels to noise were measured for 23 workers. Twenty-one (91%) of those workers measured were exposed to 85 dB(A) or higher, (the occupational exposure limit for an 8-hour exposure period). Maximum exposure levels were found to be at 102 dB (A). Hearing tests were then conducted on 97 male workers at those 36 factory sites. Twenty (21%), 30 (31%) and 10 (10%) of the workers measured were classified into a "precursory symptom group", a "slight hearing loss group" and a "medium to serious hearing loss group", respectively, based on the aforementioned guidelines. It was found that as workers' ages increased, the percentage of workers having some degree of hearing loss increased. Specifically, it was found that there was some level of hearing loss for 93% of those studied aged in their 50's, and up to 100% in those aged in their 60's.

Adult↗

[A case of curatively resected AFP producing gastric cancer that responded remarkably to 1 course of TS-1 and showed complete loss of multiple liver metastatic tumors].

A 73-year-old woman was admitted to our hospital for evaluation of hypochondralgia, and a thorough examination revealed an AFP producing gastric cancer with multiple liver metastases. One course of TS-1 100 mg/day for 4 weeks and discontinuation for 2 weeks was started from February, 2003. After 3 months, the level of AFP reduced remarkably from 53,700 ng/ml to the normal limit. The metastatic tumors in the liver showed regression, and after 14 months, CT scanning showed that the tumors had disappeared. Since the size of the original tumor showed no change, distal gastrectomy was performed, and curability A was achieved. We consider this rare case has significant value in terms of treatment of AFP producing gastric cancer with multiple liver metastases. We think the combination of surgery and chemotherapy such as TS-1 will lead to a better prognosis in such cases.

Adenocarcinoma↗

[Relationships between dioxin concentrations in deposited dust and those in serum of workers at municipal waste incineration plants].

Relationships between concentrations of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in deposited dust and those in the serum of incinerator workers were examined at 13 municipal incineration plants. The following results were found. 1) Dust analysis showed that dominant constituents were octachlorodibenzo-p-dioxin (OCDD) and 1, 2, 3, 4, 6, 7, 8-heptachlorodibenzo-p-dioxin (HpCDD) among PCDDs, and 1, 2, 3, 4, 6, 7, 8-heptachlorodibenzofuran (HpCDF) and octachlorodibenzofuran (OCDF) among PCDFs. The toxicity equivalents (TEQs) of total PCDDs and PCDFs in the deposited dust were 0.54 to 33 ngTEQ/g, which were about 1,000 to 10,000 times as high as those in general soil. 2) The mean of serum TEQ of PCDDs, that of PCDFs and that of total PCDDs and PCDFs in the incinerator workers were 16, 12 and 28 pg TEQ/g lipid, respectively, for all the incinerator workers. Concentrations of hexachlorodibenzofurans (HxCDFs) and HpCDFs in the serum were significantly higher in the incinerator workers than the general population, which suggests that these workers had inhaled these chemicals during their work. 3) The concentration of 1, 2, 3, 4, 6, 7, 8-HpCDF and the TEQ value of PCDFs and in the serum were positively correlated with those in dust except for three plants where large-scale remodeling of the equipment was conducted within the past seven years. Consequently, deposited dust analysis may be useful for judging whether health examination containing blood dioxin measurement is necessary or not.

Adult↗

Exposure evaluation of dioxins in municipal waste incinerator workers.

In Japan, the largest source of dioxin is solid waste incineration plants. Because workers employed at these plants handle fly ash and slag contaminated by dioxins, they can take dioxins into the body during work and their health may be adversely effected. This paper describes the dioxin exposure concentration, daily dioxin intake and blood dioxin level in workers employed at municipal incineration plants. The estimated dioxin exposure concentrations were 0.5 to 7.2 pg TEQ/m3 in the daily operation and 0.2 to 92,000 pg TEQ/m3 in the periodic maintenance. It was also expected that the daily dioxin intake can exceed the tolerable daily intake (TDI) in incineration plants with fly ash of high dioxin concentration. The mean of blood dioxin concentration was 346 pg TEQ/g lipid in the highest exposed worker group of the Toyono-gun incineration plant and those were 11 to 40 pg TEQ/ g lipid in the other incineration plants.

Cities↗

Inhalation toxicokinetics of p-dichlorobenzene and daily absorption and internal accumulation in chronic low-level exposure to humans.

Inhalation toxicokinetics of p-dichlorobenzene ( p-DCB) in humans was evaluated, and the amounts of daily absorption and internal accumulation were estimated in order to obtain fundamental data for the risk assessment of chronic low-level exposure in the general population. Seven male subjects continuously inhaled about 2.5 ppm of p-DCB vapor for 1 h, and the concentration-time courses of p-DCB in their exhaled air and serum and of urinary 2,5-dichlorophenol (2,5-DCP), a major metabolite of p-DCB, were examined. The toxicokinetics of p-DCB was evaluated on the basis of the time courses using a linear two-compartment model. The amounts of p-DCB absorbed daily and the internal accumulation in chronic low-level exposure were extrapolated using the estimated toxicokinetic parameters. p-DCB was transferred from inhaled air to the body with a constant high absorption rate during exposure. The major route for elimination from the body was urinary excretion followed by metabolism, not exhalation. However, during 9-11 h after the start of exposure, the fraction of p-DCB excreted in urine was only 5-16% of the amount absorbed. Furthermore, most of the absorbed p-DCB seemed to be distributed rapidly to the tissues, such as fat, according to toxicokinetic analysis. Consequently, p-DCB seems to require a long time to be completely eliminated from the body. The amounts of daily absorption and internal accumulation were extrapolated to average 0.27 mg/day and 2.9 mg, respectively, in the subjects exposed chronically to 1 ppb of p-DCB. The amount absorbed daily agreed approximately with that extrapolated from rats which inhaled p-DCB in our previous study.

Absorption↗

[A proposed method for evaluating exposure conditions from measured values when sampling duration less than 8 hours].

In order to evaluate occupational exposure conditions, it is necessary to determine the 8-hr time-weighted average (8-hr TWA) of exposure concentrations and compare the 8-hr TWA value with the permissible exposure limit, but 8-hr sampling is difficult for the outside laboratories because of trip time. For working environment measurement, because sampling duration in a unit work area may be one hour, the measurement can be conducted in several work areas in a day. If exposure conditions can be evaluated with the 1-hr TWA values, sampling to determine the exposure concentration would be efficient and able to be completed during the work area sampling. From this point of view, methods for evaluating exposure conditions with 1-hr or more TWA values are proposed in this paper.

Humans↗

Effects of dioxin on metabolism of estrogens in waste incinerator workers.

The authors measured the concentrations of serum dioxins and urinary estrogen metabolites in 57 male waste incinerator workers to determine whether dioxin influenced the metabolism of estrogens. Concentrations of serum dioxin levels and urinary estrogen metabolites, such as estrone, 17beta-estradiol, 2-hydroxyestrone, 2-methoxyestrone, 2-hydroxyestradiol, 2-methoxyestradiol, 4-hydroxyestrone, 4-hydroxyestradiol, 4-methoxyestradiol, 16-hydroxyestrone, and estriol from the workers were measured. An analysis of covariance showed that mean estriol concentrations, adjusted for confounding factors among 3 serum dioxin levels, indicated a progressive increase with increasing serum dioxin level: 1.30, 1.41, and 2.02 nmol/mol creatinine at < 30.3, 30.3-39.7, and > 39.7 pg toxicity equivalent quantity/g lipid, respectively (F = 3.56, p = .036). This study showed that dioxin acts to metabolize estrogens to 16-hydroxyestrogens rather than to 2- or 4-hydroxyestrogens.

Adult↗

High Ki-67 labeling index in human colorectal cancer with microsatellite instability.

BACKGROUND: In the present study, we examined the relationships between microsatellite status and Ki-67 labeling index, a proliferative marker, in colorectal cancers in order to clarify the common biological profiles of familial and sporadic cases of MSI (microsatellite inability)-positive tumors. PATIENTS AND METHODS: Seventy-eight invasive colorectal carcinomas were studied. Five microsatellite loci were analyzed by polymerase chain reaction, while Ki-67 was studied by immunohistochemistry. RESULTS: The MSI was found in 15 (19.2%) of the 78 tumors, and the Ki-67 labeling index was significantly higher in the 15 MSI-positive tumors than that in the 15 MSI-negative ones (p = 0.0181). Moreover, the Ki-67 labeling index was significantly higher in the 7 tumors with MSI at more than 2 loci (MSI-H; high-frequency MSI) than that in the MSI-negative ones (p = 0.0082). CONCLUSION: The present study demonstrates that colorectal cancers with MSI show high Ki-67 labeling index irrespective of hereditary or nonfamilial cancer types, suggesting their common biological aspects distinct from MSI-negative ones.

Aged↗