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Biomedical subjects

S Horiguchi

Publications and source records attributed to S Horiguchi.

At least 91 records · Page 5Linked to original sources
PubMed1990

Nociceptive effects induced by intrathecal administration of prostaglandin D2, E2, or F2 alpha to conscious mice.

The effects of intrathecal administration of prostaglandins on pain responses in conscious mice were evaluated by using hot plate and acetic acid writhing tests. Prostaglandin D2 (0.5-3 ng/mouse) had a hyperalgesic action on the response to a hot plate during a 3-60 min period after injection. Prostaglandin E2 showed a hyperalgesic effect at doses of 1 pg to 10 ng/mouse, but the effect lasted shorter (3-30 min) than that of prostaglandin D2. Similar results were obtained by acetic acid writhing tests. The hyperalgesic effect of prostaglandin D2 was blocked by simultaneous injection of a substance P antagonist (greater than or equal to 100 ng) but not by AH6809, a prostanoid EP1-receptor antagonist. Conversely, prostaglandin E2-induced hyperalgesia was blocked by AH6809 (greater than or equal to 500 ng) but not by the substance P antagonist. Prostaglandin F2 alpha had little effect on pain responses. These results demonstrate that both prostaglandin D2 and prostaglandin E2 exert hyperalgesia in the spinal cord, but in different ways.

Animals↗
PubMed1990

Urinary N-acetyl-beta-D-glucosaminidase activity in lead-exposed workers.

The adverse effects of long-term exposure to lead dust on renal tubular functions were studied in 39 male and 7 female workers in a secondary lead refinery. Laboratory examinations showed low or moderate lead absorption levels. The N-acetyl-beta-D-glucosaminidase (NAG) activity in urine showed significant correlation with each of the lead exposure indices. NAG activity increased remarkably in lead workers with blood lead (PbB) above 80 micrograms 100g-1. Blood urea nitrogen (BUN) showed significant correlation with PbB and logarithmic urine delta-amino-levulinic acid (log(ALAU)), but not with urine lead (PbU) and logarithmic urine coproporphyrin (log(CPU)). All the other indices of renal function were almost within the normal range and showed no correlation with lead indices. This study suggests that moderate lead absorption may cause renal tubular impairment, and NAG can be one of the most sensitive indices for estimating renal dysfunction due to lead poisoning.

Acetylglucosaminidase↗
PubMed1990

Biological monitoring of occupational exposure to isopropyl alcohol vapor by urinalysis for acetone.

The relationship of the intensity of occupational vapor exposure to isopropyl alcohol (IPA) with urinary excretion of acetone and unmetabolized IPA was studied in 99 printers of both sexes, who were exposed to up to 66 ppm IPA (as time-weighted average), together with toluene, xylenes, methyl ethyl ketone and/or ethyl acetate. Acetone and IPA concentrations in urine were studied also in 34 non-exposed subjects. Acetone was detectable in the urine of most of the non-exposed, and the urinary acetone concentration increased in proportion to the IPA exposure intensity (r = 0.84 for observed, non-corrected values), whereas the correction for creatinine concentration or specific gravity of urine did not give a larger correlation coefficient. IPA itself was not found in the urine of the non-exposed, and was detectable in urine of only those who were exposed to IPA above a certain level, e.g. 5 ppm. The present study results suggest that urinary acetone is a valuable index for biological monitoring of occupational exposure to IPA as low as 70 ppm.

1-Propanol↗
PubMed1990

Epidemiological study of mortality from cancer among chromium platers.

Cancer mortality was studied among 265 male workers in 40 small plating factories (chromium, copper and nickel) where bicycle parts are plated. The study utilized record linkage with the Osaka Cancer Registry file between January 1, 1965 and December 31, 1979. The results showed that seven workers had died of cancer, and the Standardized Mortality Ratio (SMR) calculated for all cancers, stomach cancer and lung cancer were 1.13, 1.23 and 1.11, respectively, with no significant relationship found between the observed and expected values. The SMR for lung cancer among those workers with a high degree of skin ulceration and with perforation of the nasal septum was high, 11.22 and 5.13, respectively, although not statistically significant because of the small sample size in the study. The results suggest that lung cancer occurs in those subjected to a high degree of exposure to chromium.

Adult↗
PubMed1990

A consideration of salt intake from foods based on the simultaneous measurement of sodium and chlorine by neutron activation analysis.

Ordinary hospital meals for adults were simultaneously measured for Na and Cl by neutron activation analysis (NAA). Results obtained are summarized as follows: 1. Daily Na intake was estimated to be 4 to 8 g, corresponding to 11 to 18 g of salt. Daily Cl intake was estimated to be 5 to 9 g, corresponding to 7 to 12 g of salt. Their ratio was 1.6. 2. The higher values of salt intake obtained by conversion from Na intake are attributable to food additives. 3. In rating Na content, which has been reported to affect blood pressure, on the basis of salt intake, attention must be given to the fact that salt content converted from Cl content is rated to be lower than that converted from Na content.

Chlorine↗
PubMed1990

Neutron activation analysis of manganese contents in ordinary hospital meals.

Neutron activation analysis (NAA) was applied to measurement of manganese (Mn) content in food as an example of ordinary hospital meals. The results showed that: 1. NAA permits measurement of Mn with a simple pretreatment procedure in comparison with AAS (atomic absorption analysis). 2. Daily Mn intake was estimated to be about 3 mg from food, and about 4 mg from green tea. Neutron activation analysis (NAA) has been used for measuring various elements under the conditions appropriate for the irradiated or radioactivated subject of analysis. We presently applied NAA to measurement of manganese (Mn) contents in food as an example of ordinary hospital meals with an estimation of daily Mn intake.

Food Analysis↗
PubMed1989

Measurement of erythrocyte arginase activity and the effect of lead on the activity in vitro.

Measurement of arginase activity made by varying the arginine concentration and the reaction time clarified that the amount of urea formed by arginase peaked at the substrate concentration of 150 mmol/l, and increased linearly by 20 minutes. By using discs punched out from a dried blood filter paper prepared from identical human blood sample, the amount of formed urea showed linear increase up to 160 U/g.Hb. The coefficients of variation in ten measurements were 6.1% for the mean activity of 46.2 U/g.Hb and 2.1% for 152.1 U/g.Hb. No decreases in arginase activity were observed when two different dried blood filter papers were left for one week at room temperature. Intact erythrocytes were treated with various concentrations of lead from 0 to 5 mumols/l and their arginase activities were measured. The activity did not elevate linearly with the rise of lead concentration, but an almost diphasic elevation was observed. The arginase activity of erythrocytes treated with 5 mumols/l of lead was higher than that for untreated ones by 32%.

Arginase↗
PubMed1988

An experimental study on the respiratory toxicity of isopropyl alcohol.

Guinea-pigs were exposed to 400 ppm or 5500 ppm of isopropyl alcohol (IPA) for 24 successive hours, and they were killed immediately after the exposure period. The ciliary activities of the nose and trachea were examined. In addition, the epithelium of the nose and trachea was observed by scanning and transmission electron microscopy. The present study showed that exposure to 400 or 5500 ppm of IPA vapor caused deterioration of the ciliary activity and also some pathological changes. Although our study revealed that exposure to 400 ppm of IPA vapor can affect the mucosa of the nose and trachea, the ciliary activity of the 400-ppm exposure group was not too poor and morphological changes were rather mild. Recovery from such degeneration might be rapid. Therefore, our study supports the justification of the allowable IPA level recommended by ACGIH.

1-Propanol↗
PubMed1988

Pupillary changes due to work using visual display terminals.

In order to measure the degree of ocular fatigue and general fatigue among the workers using visual display terminal (VDT), pupillary dynamics were measured with open-loop light stimulation for 26 subjects of a mean age of 25.9 years. VDT loads were TV games for 30 min under indirect light of 100 lux. The eight parameters of pupillary light reflex with open-loop pupillometer were examined before and after VDT loads. On the right eyes, two parameters and one value increased 9.2% (Student's t-test: P less than 0.005, max.), 25.7% (Student's t-test: P less than 0.005, Min.) and 14.8% (Student's t-test: P less than 0.005, min/max) just after the load and then gradually decreased and returned to the pre-load level after a 10 to 15-min rest period. Two parameters increased 11.7% (Student's t-test: P less than 0.05, 1/2C) and 12.9% (Student's t-test: P less than 0.05, VD), one parameter decreased -9.0% (Student's t-test: P less than 0.05, 0.63D) and three parameters were constant (Student's t-test: L, A and VC) just after the load. On the left eyes, the same tendencies were observed. But there were no significant differences (Student's t-test) between the right and left eyes. The change pattern of the eight parameters were small in degree and similar to the changes when the sympathetic nervous system was activated.

Adult↗
PubMed1988

Toxicity of isopropyl alcohol exposure on the nasal mucociliary system in the guinea pig.

The toxicity of isopropyl alcohol (IPA) on the nasal mucosa in the guinea pig was experimentally studied, with special reference to the recovery process of the organ. The results showed that 400 ppm of IPA has an acute effect on the nasal mucosa and the recovery from such degeneration can occur in 2 weeks. When functional and morphological damages were induced by a higher level (5500 ppm) of IPA, it took over 2 weeks for complete recovery from such damage. The conclusion is that the present allowable level of IPA is reasonable from a viewpoint of the effect of short-term exposure to IPA on the nasal mucosa. In addition, a higher level of IPA exposure has a longer-term effect on the nasal mucociliary system in the guinea pig, and workers exposed to such a higher level of IPA should be given careful otolaryngological observation.

1-Propanol↗
PubMed1988

Cloning and expression in Escherichia coli of the gene for mouse tumor necrosis factor.

The mouse tumor necrosis factor (TNF) gene was isolated from a mouse genomic library. The entire sequence of the gene was determined using both an automated DNA sequencer with improved primer extension reaction conditions as well as the standard radioisotopic method. Comparison of the nucleotide sequence of the gene with that of mouse TNF cDNA showed that the mouse gene consists of four exons, like rabbit and human TNF genes. There is strong nucleotide sequence homology in the 5'-flanking region among the mouse, rabbit, and human TNF genes, suggesting that the mechanisms regulating TNF gene expression are highly conserved. Direct expression of mature mouse TNF was achieved using a plasmid constructed by site-directed mutagenesis. Purified mouse TNF produced in Escherichia coli showed cytotoxicity to mouse L cells.

Amino Acid Sequence↗
PubMed1988

[Effects of ultraviolet laser beam irradiation on rabbit cornea and lens].

Rabbit eyes were irradiated by an ultraviolet laser beam in with to investigate its effects on the corneal endothelium, thickness of the cornea, and lens. An Excimer laser beam (gas; XeCl) with wave length of 308 nm and with energy intensity of 0.02, 0.07, 0.2, 0.6, 1.7, 3.0, 4.0, or 5.1 J/cm2 was irradiated to the right eye using 3 rabbits for each energy intensity (24 rabbits in all) in order to examine changes occurring in the right eye compared with the left eye from immediately after irradiation to 32 days thereafter. The results obtained were as follows: 1. Corneal thickness UV laser beam irradiation at 0.02, 0.07, and 0.6 J/cm2 caused immediate thickening of the cornea (p less than 0.01). The cornea thickness returned to normal 14 days later. Irradiation at 3.0 and 4.0 J/cm2 resulted in remarkable thickening, which returned to normal 28 days after irradiation. By irradiation at 5.1 J/cm2, the corneal thickness increased markedly (0.333 +/- 0.019 mm in control eyes and 0.405 +/- 0.05 mm in irradiated eyes) immediately after irradiation. It tended to gradually return to normal and was reduced to the pre-irradiation thickness on the 32nd day after irradiation. 2. Corneal endothelial area and morphology (the number of angles) The area of the corneal endothelium increased after irradiation. However, no significant differences were noted at any energy intensity, because of the larger scattering of the values in the control eyes. The ratio of hexagonal cells tended to decrease even by energy intensities above 0.7 J/cm2. However, no significant differences were found at any energy intensity level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effects of styrene on wheel-running and ambulatory activities in mice.

Effects of styrene on wheel-running and ambulatory activities were investigated in mice. Sixty male mice (ICR strain) were divided into 10 groups of six mice each, and they were exposed to styrene of about 930, 425, 60, 25 or 0 ppm (control group) for 4 hours a day, 5 days a week over 2 weeks. The wheel-running and ambulatory activity tests were conducted during 2 weeks of the styrene exposure, and 1 week before and after the exposure. The wheel-running activity decreased at the high concentrations (930 and 425 ppm), and the decreased activity did not recover to the control level after cessation of the exposure. In the ambulatory activity test, styrene exposure resulted in the decrease in the activity, though the change was not concentration-dependent. The present results suggest that the behavioral effect of styrene is clearly detectable by means of wheel-running and ambulatory activities in mice.

Administration, Inhalation↗