Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 469 records · Page 26Linked to original sources

PubMed1990

Biological monitoring for workers exposed to 4,4'-methylenebis(2-chloroaniline).

Absorption of 4,4'-methylenebis (2-chloroaniline) (MBOCA) was assessed for five workers over one week in a polyurethane elastomer factory by measuring urinary MBOCA levels by high performance liquid chromatography (HPLC) using an electrochemical detector. Personal air exposure levels of MBOCA ranged from 0.2 to 8.9 micrograms/m3. The mean urinary MBOCA levels at the beginning and the end of the work shift were 3.1-81.5 and 2.4-96.6 micrograms/g creatinine, respectively. The differences between preshift and postshift urinary MBOCA values were not significant in all workers, according to the paired t-test. The urinary levels after a two-day holiday (on Monday morning) were almost equal to those of preshift levels on other weekdays. Urinary excretion of MBOCA was much higher than the estimated MBOCA levels from personal exposure measurements, suggesting that a significant amount of MBOCA is absorbed by routes other than inhalation. These results lend strong support for the need to monitor exposure control by urinary MBOCA measurement.

Air Pollutants, Occupational↗

PubMed1990

Design of a polyvinyl alcohol hydrogen containing phospholipid as controlled-release vehicle for rectal administration of (+/-)-propranolol HCl.

Polyvinyl alcohol hydrogels which contained phospholipid, egg yolk lecithin or hydrogenated soya lecithin were designed as a transrectal delivery system for propranolol hydrochloride. The hydrogel preparations containing phospholipid were prepared by a low-temperature crystallization method. The release profile of propranolol from hydrogel preparations containing phospholipid complied with Fickian diffusion (Higuchi model). The release of propranolol from the hydrogel preparation decreased with higher contents of phospholipid (approximately 2% w/w). In rats plasma concentrations of propranolol after rectal administration of hydrogel preparations containing phospholipid (1 and 2% w/w) were prolonged compared with those of rats receiving preparations without phospholipid.

Administration, Rectal↗

PubMed1990

Hard metal asthma: cross immunological and respiratory reactivity between cobalt and nickel?

Eight asthmatic patients with hard metal asthma due to cobalt underwent bronchial provocation challenge with nickel sulphate. Seven patients developed a fall in FEV1 of 20% or more after inhaling nickel sulphate, four showing an immediate response and three a late response. Eight control subjects, including six asthmatic patients, with no history of hard metal exposure, showed no bronchoconstriction in response to a provocation challenge with nickel sulphate. Specific antibodies to nickel conjugated human serum albumin were present in four of the eight patients with sensitivity to cobalt conjugated human serum albumin but were absent from the serum of 60 unexposed asthmatic patients and 25 exposed symptom free workers. These results suggest that nickel as well as cobalt sensitivity plays a part in hard metal asthma.

Adult↗

PubMed1990

Effect of saline infusion during exercise on thermal and circulatory regulations.

To quantify the effect of an acute increase in plasma volume (PV) on forearm blood flow (FBF), heart rate (HR), and esophageal temperature (Tes) during exercise, we studied six male volunteers who exercised on a cycle ergometer at 60% of maximal aerobic power for 50 min in a warm [(W), 30 degrees C, less than 30% relative humidity (rh)] or cool environment [(C), 22 degrees C, less than 30% rh] with isotonic saline infusion [Inf(+)] or without infusion [Inf(-)]. The infusion was performed at a constant rate of 0.29 ml.kg body wt-1.min-1 for 20-50 min of exercise to mimic fluid intake during exercise. PV decreased by approximately 5 ml/kg body wt within the first 10 min of exercise in all protocols. Therefore, PV in Inf(-) was maintained at the same reduced level by 50 min of exercise in both ambient temperatures, whereas PV in Inf(+) increased toward the preexercise level and recovered approximately 4.5 ml/kg body wt by 50 min in both temperatures. The restoration of PV during exercise suppressed the HR increase by 6 beats/min at 50 min of exercise in W; however, infusion had no effect on HR in C. In W, FBF in Inf(+) continued to increase linearly as Tes rose to 38.1 degrees C by the end of exercise, whereas FBF in Inf(-) plateaued when Tes reached approximately 37.7 degrees C. The infusion in C had only a minor effect on FBF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Cerebral blood flow and neuronal damage during progressive cerebral ischemia in gerbils.

A combined autoradiographic and immunohistochemical method was used to correlate the extent of focal cerebral ischemia and morphologic ischemic damage following unilateral carotid occlusion in 16 gerbils for 5-30 minutes. Immunohistochemical lesions detectable by the reaction for microtubule-associated proteins 1 and 2 were visible in the subiculum-CA1 and CA2 regions of the hippocampus and layer III/IV of the cerebral cortex after 5 minutes of ischemia (n = 4). Local blood flow was promptly reduced but still heterogeneous after 10 minutes of ischemia (n = 4); local blood flow in immunohistochemical lesions was less than 5 ml/100 g/min except in highly vulnerable regions, where flow values of 5-15 ml/100 g/min were observed. After 15 minutes of ischemia (n = 4) local blood flow in less vulnerable regions including the thalamus and caudoputamen also declined to less than 5 ml/100 g/min, and immunohistochemical lesions became visible in those regions after 30 minutes of ischemia (n = 4). On the other hand, many brain regions tolerated local blood flow of less than 5 ml/100 g/min without ischemic damage. The present study demonstrates that selective tissue vulnerability during progressive cerebral ischemia depends on the degree of hypoperfusion and on factors inherent to neurons in various brain regions.

Animals↗

PubMed1990

[Life style and the right to clean air in public places (RCA). Part 1. The relationship between life style and legal consciousness on smoking regulations].

The right to clean air in public places (RCA) could be a good indicator of health consciousness. We surveyed the consciousness of RCA among residents (20 years of age or older; n = 1500) in city D, a satellite town of Osaka, and examined the relationship between life style and the knowledge aspect of RCA, one of the three aspects of the consciousness concerning RCA. Knowledge of laws concerning the smoking regulations in public places are divided into two categories. One is knowledge of laws concerning general matters, and the other is knowledge of laws concerning concrete matters. Therefore, we get two kinds of relationships. These are the relationship between life style and knowledge of laws concerning general matters, and the relationship between life style and knowledge of laws concerning concrete matters. We examined these two relationships by using Student's t test, and tried to determine the individual life style closely related to the scores for knowledge of laws with the chi-square test. We got following results. (1) The relationship between life style and knowledge of laws concerning general matters Knowledge scores got higher as the life style scores (HPI) became higher. This trend could be detected in all four subgroups. The scores of male subgroups were generally higher than those of female subgroups. This could be construed as follows: those who take care of their physical health have a lot of knowledge of laws concerning smoking regulations. (2) The relationship between life style and knowledge of laws concerning concrete matters Knowledge scores got lower as the life style scores became higher. This trend was almost the same in all four subgroups. The scores of male groups were generally higher than those of female subgroups. This trend could be construed as follows: men and women whose HPI is lower get more opportunities to be in the public places where smoking is totally allowed (e. g., bars) irrespective of their smoking status.

Adult↗

PubMed1990

[Life style and right to clean air in public places (RCA) (Part 2). The relationship between life style and the aspect of knowledge level of the consciousness towards smoking regulations among employees].

The right to clean air in public places (RCA) is a useful indicator of health consciousness. We surveyed the life style and consciousness towards RCA among employees working at the head office of a major company in Osaka, and examined the relationship between life style and knowledge aspect of RCA, one of the three aspects of consciousness towards RCA. Knowledge on laws concerning smoking regulations in public places was classified into two categories. One was knowledge on laws concerning general matters and the other was knowledge on laws concerning concrete and specific matters. Therefore, there are two kinds of relationship; the relationship between life style and knowledge on laws concerning general matters and the relationship between life style and knowledge on laws concerning concrete matters. These two relationships were examined with statistical procedures. Mean scores of knowledge on laws of subgroups divided by HPI score (POOR, MODERATE and GOOD) within groups divided by age and sex ("M. smoker," "M. nonsmoker" and "F. nonsmoker") were compared by t-test. Life style related to knowledge score was checked by correlation coefficient. The following results were obtained. (1) Relationship between life style and knowledge on laws concerning general matters Knowledge scores and their age-adjusted scores of MODERATE groups were the lowest among the 3 groups ("M. smoker," "M. nonsmoker," "F. nonsmoker"). This set of questions was designed to measure the knowledge level on laws concerning general matters. One would have abundant knowledge if one is health-conscious. In other words, those who do many things beneficial to physical health and have a high HPI have a wealth of knowledge on laws concerning smoking regulations on general matters. In the case of the employees, MODERATE groups were less health-oriented than others ("POOR," "GOOD") within the 3 groups ("M. smoker," "M. nonsmoker," "F. nonsmoker"). (2) Relationship between life style and knowledge on laws concerning concrete matters This set of questions was designed to measure the knowledge on laws concerning concrete and specific matters. To attain high scores, it is necessary to have more smoking experiences in various types of indoor places. POOR group of "M. smoker" and MODERATE groups of "M. nonsmoker" and "F. nonsmoker" had high knowledge scores. They were considered to have greater opportunities to visit public places where smoking is permitted (for example, bars) irrespective of their smoking status.

Adult↗

PubMed1990

[Stress analysis of titanium-hydroxyapatite implant. Effect of titanium diameter on reinforcement and calculation of implant diameter].

In order to evaluate the effect of titanium diameter on reinforcement of titanium-hydroxyapatite implant and calculate the diameter of the implant under loading, stress analysis was performed using the finite element method. In finite element model, 100% or 70% of root length was supported by PMMA in place of bone and the implant was loaded 15 kgf at 45 degrees of the implant axis. The results were obtained as follows, 1. In the case of 100% support, the titanium diameter had little effect on the reinforcement of the implant, whereas in the case of 70% support, it had much effect. 2. The diameter of this implant was calculated to be more than 3.7 mm under loading. From these results and the view point of manufacturing techniques, the diameter of this implant was supposed to need 4.0 mm and that of titanium was to be 2.0 mm.

Dental Implants↗

PubMed1990

[DNA damage test in forestomach squamous epithelium of F344 rat following oral administration of ethyl acrylate].

The alkaline elution assay were applied for testing DNA damage of forestomach squamous epithelium in male F344 rat after oral administration of ethyl acrylate (EA), a forestomach carcinogen. The animals were starved for 18 hr and then given a single oral dose of EA. No DNA damage were observed by EA at the concentration of 0.1-4.0%. The weights of the forestomach increased with EA dose, reflecting edema and inflammation, but that of glandular stomach did not change with its dose.

Acrylates↗

PubMed1990