Thermotactile perception thresholds measurement conditions.

The purpose of this paper is to investigate the effects of posture, push force and rate of temperature change on thermotactile thresholds and to clarify suitable measuring conditions for Japanese people. Thermotactile (warm and cold) thresholds on the right middle finger were measured with an HVLab thermal aesthesiometer. Subjects were eight healthy male Japanese students.

Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine values measured by an ELISA correlated well with measurements by high-performance liquid chromatography with electrochemical detection.

Measurement of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) has recently become more popular as a means of assessing oxidative stress in the human body. Although using high-performance liquid chromatography with electrochemical detection (HPLC-ECD) is a reliable method of measuring 8-oxo-dG, easier and simpler alternative methods may be preferred, if they are quantitatively accurate. The ELISA method is the likeliest candidate for a useful alternative.

Effects of toluene exposure on signal transduction: toluene reduced the signaling via stimulation of human muscarinic acetylcholine receptor m2 subtypes in CHO cells.

The organic solvent toluene is used widely in industry and is toxic to the central nervous system (CNS). To clarify the mechanisms of CNS toxicity following toluene exposure, especially with respect to the G protein-coupling of receptors, we determined the effects of toluene on the activation of Gi by stimulating human muscarinic acetylcholine receptor m2 subtypes (hm2 receptors) expressed in Chinese hamster ovary (CHO) cells. We first examined whether toluene affects the inhibition of adenylyl cyclase by Gi.

Comparison of the prevalence of ventricular and supraventricular premature beats with 24-hour Holter electrocardiography between hypertensive and normotensive shift workers in a manufacturing company.

We conducted 24-hour Holter electrocardiography (ECG) among shift workers to assess whether there were differences in the prevalence of ventricular apd supraventricular premature beats between hypertensive (HT) and normotensive (NT) workers. Among the selected 24 male shift workers, 20 were fitted with 24-hour Holter ECG monitors. Nine workers were in the HT group and 11 the NT group.

Cancer mortality among man-made graphite electrode manufacturing workers: results of a 38 year follow up.

Background And Aims: To examine the risk for cancer mortality among workers exposed to coal tar and coal tar pitch volatiles in a man-made graphite electrode factory. The risk for cancer mortality in this type of factory is still inconclusive, although coal tar and coal tar pitch are recognised as human carcinogens.

Methods: The study cohort consisted of 332 male employees who served more than five years in the period 1951-74.

Disturbed sleep-wake patterns during and after short-term international travel among academics attending conferences.

Objectives: To examine variations in sleep and wakefulness associated with international travel.

Methods: Ten academics in Japan were studied while traveling abroad to participate in conferences. Wrist activity and a daily log were recorded continuously for 1 week before, during, and for 1 week after travel.

Effects of a standing aid on loads on low back and legs during dishwashing.

In order to prevent low back pain during dishwashing, we developed a standing aid for supporting the forward bending posture, and then evaluated the effects of the standing aid on decreasing load on the low back and legs. Eight female volunteers were asked to wash plates for 60 minutes in each of three working postures: (a) without the standing aid, (b) with the standing aid under the thighs, and (c) with the standing aid under the shins. The following were measured: electromyogram (EMG), electrocardiogram (ECG), the force applied to the standing aid, the ground reaction force, the bending angle of the trunk, the bending angle of the knee, and local discomfort in body regions.

DNA microarray analysis of human gene expression induced by a non-lethal dose of cadmium.

Cadmium (Cd) is a hazardous heavy metal present in working and living environments. Cd affects many cellular functions, but little is known about the mechanisms of its toxicity and cellular defense against it. Recently, advanced gene expression analysis employing DNA microarrays provided us the means to profile the expression of thousands of genes simultaneously.

Association of low job control with a decrease in memory (CD4+ CD45RO+) T lymphocytes in Japanese middle-aged male workers in an electric power plant.

To clarify the relationship between perceived job stress and lymphocyte subpopulations, a cross-sectional study was conducted in 231 male electric power plant workers (aged 40 to 60, mean 46 years). Job stress, i.e.

An ergonomic questionnaire survey on the use of computers in schools.

A questionnaire was sent out to elementary, junior high and high schools in Yokohama and Kawasaki Cities from January to March 1998 regarding the use of personal computers by pupils and students. The survey included the questions that asked how often and in what environment computers are used, whether any instructions are given as to their use, children's working posture, and the effect on health. The results show that most schools are slow to develop instructive programs from the environmental or ergonomic point of view.

Evaluation of blue-light hazards from various light sources.

Visible light of short wavelength (blue light) may cause a photochemical injury to the retina, called photoretinitis or blue-light hazard. In this study, various light sources were evaluated for blue-light hazard. These sources include the sun, the arc associated with arc welding and plasma cutting, molten steel, iron and glass, the interior of furnaces, the arc or envelope of discharge lamps, the filament or envelope of incandescent lamps, the envelope of fluorescent lamps and light-emitting diodes.

[Stevens-Johnson syndrome accompanied by acute hepatitis in workers exposed to trichloroethylene or tetrachloroethylene].

Since the late 1980s, there has been an increasing tendency in the number of case reports on Stevens-Johnson syndrome accompanied by acute hepatitis in workers exposed to trichloroethylene from Asian countries. Recently, mass outbreaks of it have been disclosed in the Philippines and China. Besides trichloroethylene, although the number is small, a similar health disorder has also occurred in workers using tetrachloroethylene.

Relationships between chemical structures and mutagenicity: a preliminary survey for a database of mutagenicity test results of new work place chemicals.

A database of mutagenicity test results of new chemicals has been developed. Based on the amendment of the Industrial Safety and Health Law (ISHL) in 1979, manufacturers and importers in Japan are required to register any new work place chemicals with bacterial mutagenicity test results. At present more than ten thousand substances have been examined.

Moderate alcohol consumption reduces urinary 8-hydroxydeoxyguanosine by inducing of uric acid.

Recent studies suggest that moderate alcohol consumption is associated with a low risk of cancer, coronary heart disease, and other diseases. Most of these diseases are considered to be related to the action of reactive oxygen species (ROS) at certain stages of disease progression. However, considerable evidence exists indicating that ethanol generates ROS in vivo.

Effects of aldehyde dehydrogenase-2 genetic polymorphisms on metabolism of structurally different aldehydes in human liver.

Genotype analysis of the aldehyde dehydrogenase (ALDH)-2 gene was performed using an improved simplified method, and effects of the genotype on the metabolism of a variety of aldehydes in different fractions of human liver cells were investigated. The effects of sex, aging, smoking, drinking alcohol, liver function, and various drugs on ALDH activity were also analyzed. Of the 39 subjects, eight were heterozygotes of the wild (ALDH2*1) and mutant (ALDH2*2) alleles, and the others were homozygotes of the wild allele.

Effects of 1-bromopropane, 2-bromopropane, and 1,2-dichloropropane on the estrous cycle and ovulation in F344 rats.

The present study was performed to investigate comparatively the toxic effects of inhalation exposure of 1-bromopropane, 2-bromopropane, and 1,2-dichloropropane on reproductive physiology, particularly on the estrous cycle and spontaneous ovulation in female F344 rats. The rats received inhalation exposure to different halogenated propanes, and were exposed daily for 8 h throughout almost 3 weeks to 0,50,200 and 1000 ppm of 1-bromopropane or 2-bromopropane, or to 0,50,100 and 200 ppm of 1,2-dichloropropane. Throughout the exposure period of 1-bromopropane or 2-bromopropane, the ratio of the number of estrous cycle of 6 days or longer to the number of all cycles in both 1000 ppm groups were about two-fold the ratio in each control group, however, no significant difference was found between the ratios of exposed and control groups.

Influence of 2-bromopropane on reproductive system--short-term administration of 2-bromopropane inhibits ovulation in F344 rats.

The present study was performed to investigate the toxic effects of 2-bromopropane (2BP) on the female reproductive system. Female F344 rats were administered 2BP (500 or 1000 mg/kg, i.p.

Ultraviolet radiation emitted by CO(2) arc welding.

The arcs associated with arc welding emit high levels of ultraviolet radiation (UVR), and this often causes acute injuries in the workplace, particularly photokeratoconjunctivitis. It is important to know the level of UVR emitted by arc welding under various conditions, as this information will help in evaluating potential UVR hazards in welding workplaces and taking protective measures against it. In this study, the ACGIH effective irradiance for UVR was measured experimentally for CO(2) arc welding in order to evaluate its UVR hazards.

A new approach to assess low frequency noise in the working environment.

To assess high-level low frequency noise in the working environment, adverse extra-aural effects caused by the noise should be taken into account. The human body vibration induced by low frequency noise, 'noise-induced vibration', was measured on the body surface and the equal-acceleration level contours of the vibration were tentatively estimated. With these contours, we can predict the magnitude of noise-induced vibration at every measuring position on the body surface.

Involvement of Bcl-2 family genes and Fas signaling system in primary and secondary male germ cell apoptosis induced by 2-bromopropane in rat.

Epidemiological surveys and animal experimental studies suggest that exposure to 2-bromopropane (2-BP) could result in reproductive and hematopoietic disorders. The objectives of this study were to investigate the role of apoptosis in 2-BP-induced testicular toxicity and whether this process involves Bcl-2 family genes and the Fas signaling system. Rats were injected percutaneously with 1350 mg/kg 2-BP for 1 to 5 days and then were euthanized at 6 or 12 h after one dose, 6 h after two, three, or five doses, and 2 or 9 days after the final treatment.

In isolated DNA, formamidopyrimidine-DNA glycosylase-sensitive sites determined by electrophoresis correspond to the amount of 8-oxo-7,8-dihydro-2'-deoxyguanosine by HPLC-ECD.

Several methods have been developed for determining the amount of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in DNA. In the present study, we compared an electrophoretic method that uses formamidopyrimidine-DNA glycosylase (FPG protein) with a HPLC-ECD method. Firstly, we produced 8-oxodG in lambda DNA with methylene blue and visible light and cleaved it in one-half of the modified DNA enzymatically with FPG protein.

Lower percentage of CD56+ cells associated with long working hours.

In a study of 142 Japanese men from a cross-section of the workforce of a technology development company, we found that the percentage of CD56+ cells was inversely correlated with the number of hours worked per week. A low CD56+ cell percentage was associated with longer weekly working hours and shorter daily sleeping hours.

Urinary 8-oxo-7, 8-dihydro-2'-deoxyguanosine and biopyrrins levels among construction workers with asbestos exposure history.

It has been suggested that oxidative stress is associated with the cancers caused by asbestos. Since construction workers are sometimes exposed to low levels of asbestos, we investigated whether oxidative stress was elevated in construction workers who had been exposed to low levels of asbestos. The subjects were 48 Japanese construction workers.

Estimation of fibrous aerosol deposition in upper bronchi based on experimental data with model bifurcation.

Lung deposition of fibrous aerosol was studied by using a model of the lung bifurcation with dimensions based on the symmetric model A of Weibel. The fibrous aerosols were introduced to the model under steady inspiratory flow conditions. Glass fibers depositing in the daughter tubes and these escaping from them were observed under a scanning electron microscope (SEM).

Negative regulatory role of Sp1 in metal responsive element-mediated transcriptional activation.

Transcription of mammalian metallothionein (MT) genes is activated by heavy metals via multiple copies of a cis-acting DNA element, the metal-responsive element (MRE). Our previous studies have shown that certain MREs of the human MT-IIA gene (MREb, MREc, MREd, and MREf) are less active than the others (MREa, MREe, and MREg). Gel shift analysis of HeLa cell nuclear proteins revealed that whereas the active MREs strongly bind the transcription factor MTF-1 essential for metal regulation, the less active MREs bind another distinct protein, MREb-BF.