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Biomedical subjects

Y Fukaya

Publications and source records attributed to Y Fukaya.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Injury to ascending aorta by cross-clamp--histologic evaluation].

To evaluate the injury to ascending aorta by cross-clamp, the trauma to the vessel wall was examined microscopically and the occlusive intensity of the vascular clamp was measured. Six patients were underwent total replacement of the ascending aorta and the aortic arch for aortic dissection. The ascending aorta and the aortic arch were resected during operation, the clamped regions of the ascending aorta were cut into the four pieces (the distal site, two part of the medial site, the proximal site applied by the vascular clamp) after operation. The four pieces of the ascending aorta were examined microscopically. The occlusive intensity of the vascular clamp were measured at the distal site, the medial site, and the proximal site by the load-measuring scale. The trauma to the vessel wall were classified to three degrees (grade 1 to grade 3). Grade 1 showed the minimal changes--narrowing of interstices between collagen fibers and muscle fibers in the media. Grade 2 showed the moderate changes--decrease of collagen fibers, atrophy and disruption of smooth muscle and elastic fiber in the media. Grade 3 showed the severe changes--disruption of the intima and defluvium of endothelial cells. The occlusive intensity of the vascular clamp were 1.0 kg at the distal site, 1.9 kg at the medial site and 3.6 kg at the proximal site, respectively. In the microscopic examinations, grade 1 changes were most frequent at the distal site, grade 1 and grade 2 changes were observed equally at the medial site, grade 3 change was observed only at the proximal site. The degree of the trauma to the vessel wall becomes severer in proportion to increase of the occlusive intensity of the vascular clamp.

Adult↗
PubMed1995

[Relationship between vibratory sense threshold and blood lead concentration in ceramic color workers and transfer printing manufacturers].

We measured vibratory sense thresholds (VSTs) at 63Hz and 125Hz on the third fingertip of the right hand and on the third toe of the right foot of 74 male workers. The subjects were workers engaged in manufacturing ceramic color and transfer printing paper, whose blood lead (Pb-B) levels were 2-58 micrograms/dl. They were divided into three groups according to the Pb-B levels, namely, below 9, 10-19, and 20 micrograms/dl or more. For statistical analysis, simple and partial correlations, and Scheffé's multiple comparison between the least squares means were used. The VSTs on the fingertip as well as on the toe showed a significant correlation with age. The VSTs at 125Hz on the fingertip were also significantly correlated with alcohol consumption and cigarette smoking. Controlling for age, systolic blood pressure, alcohol consumption and smoking habit, a significant dose-effect relationship was observed between the VSTs at not only 63Hz but at 125Hz on the fingertip, and each of the corresponding Pb-B levels. A similar tendency was also observed at the two frequencies on the toe. The measurement of VSTs was considered to be an effective screening test for sensory nerve disorders caused by lead poisoning.

Adult↗
PubMed1995

Health status of the workers using mechanized hand tools in an electric parts' maker.

The aim was to clarify the relations between the health status of the workers operating mechanized hand tools (MT). MT included electric drivers and air drivers, and the working conditions in an electric parts' maker. Fifty-nine female workers underwent the special examination for vibration hazards, made up of 39 MT operators (Group A) and 20 controls (Group B) who worked without MT at the same plant. The authors made questions about their health and working conditions and physical examinations. The measured items of the peripheral nervous system were the vibratory sensation and sensory nerve conduction velocity (SNCV) in the hand and arm. Those of the musculoskeletal function were pinching power, grasping power, back strength, and tapping ability. The frequency of the complaints "tingling of hands" and "numbness of hands" and "difficulty of finger extension" in Group A was significantly higher than in Group B. The frequency of "swelling of hands" and "heavy feeling of arms" in Group A had a higher tendency than in Group B. There was no difference in the results of physical examinations and vibratory sensation. Pinching power and grasping power (both hands) and back strength in Group A was greater than in Group B. Median SNCV in the hand in Group A was significantly slower than in Group B. The maximum vibration acceleration level (0.56-1.8 m/s2) of the MT used at the plant did not exceed the exposure guideline of ISO. The results suggest that although the vibration level was low enough, physiological changes appeared in the workers with MT.

Adult↗
PubMed1994

Determination of 3,4-dimethylhippuric acid as a biological monitoring index for trimethylbenzene exposure in transfer printing workers.

The relationship between exposure to 1,2,4-trimethylbenzene (1,2,4-TMB) and urinary concentration of 3,4-dimethylhippuric acid (3,4-DMHA), one of its metabolites, was studied in workers involved in transfer printing. Airborne TMBs were sampled by an organic vapor monitoring badge and analyzed by capillary gas chromatography. Urinary 3,4-DMHA and creatinine were analyzed under the same conditions of high-performance liquid chromatography. The exposure concentration of 1,2,4-TMB among workers was around 25 ppm, the threshold limit value (TLV). The urinary concentration of 3,4-DMHA was low at the start of each shift and high at the end. Exposure to the TLV (25 ppm) of 1,2,4-TMB results in a urinary 3,4-DMHA concentration of 410 mg/g creatinine (r = 0.897, P < 0.001). Urinary 3,4-DMHA concentration could be used as a biological monitoring index for 1,2,4-TMB exposure.

Adult↗
PubMed1994

Surgical management of left main coronary artery aneurysm.

To date only 7 patients with left main coronary artery aneurysm associated with atherosclerosis have undergone surgical treatment. This report reviews a case of atherosclerotic aneurysm of the left main coronary artery with concurrent stenotic coronary artery disease that was successfully treated by direct approach to the left main coronary artery aneurysm and establishment of coronary artery bypass grafts.

Aged↗
PubMed1993

Relations between lead exposure and peripheral neuromuscular functions of lead-exposed workers--results of tapping test.

In this study, four experiments using the tapping test were conducted to evaluate the possible subclinical effects of lead exposure on the neuromuscular systems of lead workers at some transfer printing factories in Japan. Decreases in the tapping ability appeared coincidentally with higher blood lead levels. The recovery of the tapping ability after 30 sec rest in the groups of 30-45 micrograms/dl and above 45 micrograms/dl PbB was worse than that in the group with less than 29 micrograms/dl PbB. The recovery of the decreased tapping ability after 60 sec rest was better even in the group with 30-45 micrograms/dl PbB. The tapping ability for 0-10 sec at the first tapping test was sustained after 30 or 60 sec rest in the group with the PbB below 29 micrograms/dl; however, the tapping ability at the second and third tapping test decreased in the two groups with the PbB level above 30 micrograms/dl. The decreased finger tapping speed may be functional evidence of low-grade motor neuropathy among the workers with higher levels of lead absorption.

Adult↗
PubMed1993

Improvement of cardiac function impaired by repeated ischemic arrests in isolated rat hearts.

We investigated the effects of coenzyme Q10 and verapamil, either alone or in combination, on cardiac function impaired by repeated ischemic arrests and reperfusion in the isolated rat heart. In the group with a single ischemic arrest, the aortic flow, cardiac output, stroke volume, coronary flow, and heart rate recovered well (72% to 100% of the prearrest values). In the repeated-arrest group, the recovery of aortic flow (24%), cardiac output (30%), stroke volume (40%), or coronary flow (63%) was much poorer than that in the single-arrest group. Pretreatment with coenzyme Q10 given intraperitoneally improved aortic flow, cardiac output, stroke volume, coronary flow, and heart rate. The addition of verapamil to the reperfusion solution also protected the cardiac function with a decrease in heart rate. However, combination therapy with coenzyme Q10 and verapamil further increased the recoveries of aortic flow, cardiac output, stroke volume, and coronary flow to 57%, 61%, 77%, and 84%, respectively, which were better than the values after treatment with coenzyme Q10 or verapamil alone. We, therefore, suggest that treatment with coenzyme Q10 or verapamil, alone or in combination, in addition to St. Thomas' Hospital solution effectively protects cardiac function impaired by repeated ischemic arrests and reperfusion.

Animals↗
PubMed1993

[Lead exposure of workers in the ceramics industry and relevant factors].

To clarify lead exposure and factors relevant to it, an occupational health survey and air lead-concentration survey were conducted among 425 workers in the ceramics industry in the Seto region in Aichi Prefecture. As for biological monitoring, blood lead level was measured according to sex, job, product, factory size and duration of lead exposure. The following major findings were obtained in the present analysis. Workers making dolomite novelties showed higher blood lead levels than those making porcelain novelties, semi-porcelain novelties and tableware. The difference in blood lead level by job was statistically significant, but not that by factory size. In males, the highest blood lead level was found for spray painting work (28.7 micrograms/dl), followed by glazing work (28.0 micrograms/dl), kiln work (23.3 micrograms/dl) and painting work (22.3 micrograms/dl). In females, the blood lead level for painting work (13.5 micrograms/dl) was lower than those for glazing work (26.1 micrograms/dl) and kiln work (31.4 micrograms/dl). The blood lead level was significantly increased with the number of years of lead exposure in females (painting work). It was coincidentally clarified that the environmental lead concentration varied according to the job in which workers were engaged. As protective measures against lead exposure for workers in the ceramics industry, the development of nonlead paint and glaze and the introduction of more effective dust collectors at the workplace should be established.

Adult↗
PubMed1993

[Experimental study on the hydrodynamic performance of "valved pericardial roll"].

Optimal configuration and hydrodynamic performance of "Valved Pericardial Roll (VPR)" as an external conduit was studied using a mock circulatory system which was able to simulate a right cardiac function of infants. Results were as follows: 1) Cardiac output produced by VPR was consistently higher than that by non valved pericardial roll. This result showed the hemodynamic effectiveness of VPR at early stage of operation. 2) Cardiac output by VPR tended to decreased as an elevation of afterload and/or an increment of pulse rate. This result exhibited that VPR had a comparable performance to the Ionescu-Sihley pericardial valve, a satisfactory performance of which was recognized clinically. 3) The optimal configuration related to the length of valve leaflet (LVL) were obtained from the simulation data. VPR with two leaflets produced the best performance when each LVL was design to be 95% of the roll diameter. Among the VPR with three leaflets, the best LVL was 85%. Thus far, VPR which was developed based on the above fundamental studies, indicated satisfactory performance as compared to the conventional surgical treatment.

Animals↗
PubMed1992

Recording the bladder electromyogram for bladder activity evaluation during post-operative urinary urgency.

When the intravesical pressure cannot be measured because of continuous drainage, bladder electromyography is an alternative means of evaluating the functional condition of the urinary bladder. However, many problems that accompany this procedure have not been solved. In the present study we tried bladder electromyography with a newly-developed carbon fiber electrode in a patient who underwent an open prostatectomy. It was helpful in recognizing the relationship between urinary urgency and the spasmic activity of the vesicular detrusor muscle.

Aged↗
PubMed1992

[A case of aortic valve stenosis and regurgitation with idiopathic thrombocytopenic purpura].

A patient of aortic valvular disease with idiopathic thrombocytopenic purpura underwent aortic valvular replacement. We report a preventive measure against the intra and postoperative bleeding. The patient was a 67-year-old man. He was diagnosed as aortic valvular stenosis with regurgitation. There was no abnormal data about the coagulation test. Thrombocyte count was 8.2 x 10(4)/mm3, but thrombocytopenic life span had shortened 3.8 days. So, we used gamma-globulin 400 mg/kg/day for 5 days before the day of operation and infused blood platelets on the day of operation. There was no problem intra and postoperative period. On the 14th postoperative day thrombocyte count increased to 22.9 x 10(4)/mm3, and thrombocytopenic life span returned to normal range (7.6 days). But on the 45th day of postoperation, thrombocyte count decreased to 11.0 x 10(4)/mm3. We think that many gamma-globulin medication is a useful method to prevent intra and postoperative bleeding resulting from idiopathic thrombocytopenic purpura.

Aged↗
PubMed1992

[The surgical treatment for the Stanford type A aortic dissection].

Twenty-nine patients who underwent operation at Shinshu University Hospital for the Stanford type A dissecting aneurysm were analysed. The patients were operated on in the acute stage within 2 weeks after onset. In 13 of these 26 acute cases, the graft replacement of the ascending and arch of the aorta was performed (group A). The patients were operated under a separate perfusion to the brain and the distal anastomosis to the proximal portion of the descending aorta was performed using the method of open distal anastomosis. In other 13 cases, the graft replacement of the ascending aorta was performed (group B). Operative mortality rate was 19% in this series (group A: 23%, group B: 15%). There was no significant difference in their operative mortality of acute stage. And there was also no significant difference in their post operative course of acute stage operations. We concluded that the graft replacement of the ascending and arch of the aorta was better than the graft replacement of the ascending aorta alone for the patients with Stanford type A acute aortic dissection.

Aged↗