Biomedical subjects

H Horii

Publications and source records attributed to H Horii.

18 recordsLinked to original sources

PubMed1992

Asbestos-related pleural thickenings in Japanese sake brewers.

Asbestos was long used as an additive material for the filtration of many kinds of alcoholic beverages. There has been, however, only one case report of a distiller in Italy showing pleural thickenings and lung parenchymal fibrosis due to exposure to asbestos. We report a retired Japanese sake brewer who showed bilateral calcified pleural plaques on chest X-ray films. X-ray diffraction analysis and energy disperse X-ray microanalysis demonstrated the additive material used for sake filtration to be almost pure chrysotile. Furthermore, 17 cases showing probably asbestos-related pleural thickenings were found on examination of 235 chest X-ray films of male workers at different sake breweries. These findings indicate that Japanese sake brewers should be listed as workers at possible risk of asbestos-related health problems.

Aged↗

PubMed1992

Positron emission tomographic measurement of acute hemodynamic changes in primate middle cerebral artery occlusion.

Specific hemodynamic changes in acute ischemia were investigated using a middle cerebral artery occlusion primate model and positron emission tomography. The cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate for oxygen were measured 1, 3, and 9 hours after occlusion. OEF showed an increase in ischemic areas, and especially where CBF was below 18 ml/100 gm/min 1 hour after occlusion the OEF increased significantly (0.69 +/- 0.20, p < 0.05). Nine hours after occlusion, the OEF values were lower compared to those 1 and 3 hours after occlusion. Areas where CBF ranged from 18 to 31 ml/100 gm/min showed an increase in OEF at all times (p < 0.05). Clearly, OEF changes remarkably in the acute stage.

Animals↗

PubMed1991

A new method of myocardial revascularization by laser.

There are some problems in surgical treatment for those patients with small branches or diffuse stenotic lesions of the coronary arteries, for whom coronary artery bypass grafting can not be carried out at all. To resolve these problems, we have planned to supply arterial blood from the left ventricle into the ischemic myocardium through holes cut into the myocardium by laser. It was clearly recognized that arterial blood could be hemodynamically supplied from the left ventricle into the ischemic myocardium. In trials on dogs laser holes 0.2 mm in diameter have been shown microscopically to be patent even 3 years after their creation, thus this procedure could be used as a new method of myocardial revascularization. Consequently, myocardial revascularization by laser was employed in a 55-year-old male patient with severe angina pectoris who had undergone pericardiectomy 2 years before. He is doing well 5 years and 3 months after surgery.

Angina Pectoris↗

PubMed1990

Effects of N-methylmercaptoimidazole on the disposition of MPTP and its metabolites in mice.

The effects of N-methylmercaptoimidazole, an alternative substrate for flavin-containing monooxygenase, on the disposition of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its metabolites, 1-methyl-4-phenyl-1,3-dihydropyridine (MPDP+) and 1-methyl-4-phenylpyridine (MPP+) in plasma and in brain tissues were studied in mice. Pretreatment of mice with N-methylmercaptoimidazole caused a significant (P less than 0.01) increase in the plasma concentration of MPTP, whereas there was no significant change in the plasma concentrations of MPDP+ and MPP+. N-Methylmercaptoimidazole caused a significant (P less than 0.01) increase in the levels of MPTP, MPDP+ and MPP+ in both the striatum and cortex. The conversion rates of MPTP to MPDP+ to MPP+ in whole brain homogenates were not affected by N-methylmercaptoimidazole. These results suggest that N-methylmercaptoimidazole increases the amount of MPTP delivered from the peripheral to the central nervous system, presumably by inhibiting MPTP N-oxygenation via the hepatic microsomal flavin-containing monooxygenase. An increased level of striatal MPP+, caused by the oxidation of more MPTP by brain monoamine oxidase, appears to be the mechanism by which the neurotoxicity of MPTP is enhanced by N-methylmercaptoimidazole.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1989

[Experimental and clinical studies on the laser application in the cardiovascular surgery; analysis of clinical experience of 112 patients].

Since 1980, we have applied lasers experimentally in the following three categories in the fields of cardiovascular surgery. That is, Group 1: New myocardial revascularization in the patients whose coronary arteries are too small or diffuse due to atherosclerosis, Group 2: Laser vascular anastomosis especially for small-caliber vessels, such as coronary artery bypass grafting, Group 3: Laser angioplasty for obstructive arterial disease. Subsequently, efficacy of laser application could be obviously recognized in these fields. On the basis of excellent results of our experimental studies, laser was clinically employed for 112 patients with anginal pain, intermittent claudication and renal failure. They consisted of new myocardial revascularization in one case and vascular anastomosis in 89 cases including 7 cases (LIMA-LAD2, SVG-LAD5) of the coronary artery bypass grafting and laser angioplasty in 22 cases including 5 cases (LAD3, RCA2) of intraoperative laser coronary angioplasty. Optimal conditions of vascular anastomosis were 20-40mW in output and 6-12sec/mm in irradiation time. On the other hand, optimal conditions for laser angioplasty were 6 watts in output and 3sec in irradiation time for each shot. Laser irradiation was carefully repeated according to the grade of atherosclerotic changes. These patients are doing well without any complications throughout laser. Our experimental and clinical experiences of laser application in the fields of the cardiovascular surgery were presented in detail.

Adolescent↗

PubMed1989

[Septic shock].

Explore the source record for details and available documents.

Humans↗

PubMed1988

Quantitative measurement of renal function using Ga-68-EDTA.

We studied renal function using a positron emission tomography with C15O gas and 68Ga-EDTA in 6 normal subjects (male, 21-77 years old). The blood volume (ml/100 g (kidney] was 19.2 +/- 1.8 for the one 21 years old subject and 11.8 +/- 2.0 for the rest (65-77 years old). The glomerular filtration rate (ml/min/100 g (kidney] was 57.8 +/- 1.1 for the 21 years old subject and 30.4 +/- 2.8 for the rest.

Aged↗

PubMed1987

An alternative method of vascular anastomosis by laser: experimental and clinical study.

In vascular surgery, it is now very difficult to maintain the long-term patency after a conventional vascular anastomosis, especially for small-caliber vessels. A low-energy CO2 laser was experimentally employed to make a vascular anastomosis with only a few sutures. Subsequently, it could be confirmed that optimal conditions for vascular anastomosis by laser were 20-40 mW in output and 6-12 sec/mm in irradiation time. On the other hand, pressure tolerance test as well as tensile strength test and microscopic examinations at the sites of anastomoses by laser were compared with the conventional suture method. There were no significant differences between laser and suture methods. On the basis of the excellent results of this study, the laser was clinically applied for anastomoses of the peripheral vessels in 35 patients. The first clinical laser application in the world was successful in a 44-year-old female patient with chronic renal failure in 1985. All patients are doing well without any complications from vascular anastomosis by laser. From these experimental and clinical studies, it can be concluded that anastomosis by laser should be recommended for small-caliber vessels such as aortocoronary bypass surgery.

Adult↗

PubMed1987

[A new method of vascular anastomosis by CO2 laser: experimental and clinical study].

It is difficult to maintain the long-term patency after conventional anastomosis especially for the small caliber vessels. Since 15 years we have performed aortocoronary bypass with suture materials for the patients with ischemic heart disease. There are some problems in maintaining the long-term patency of the bypass grafts. Low energy CO2 laser was utilized to make vascular anastomosis with a few stay sutures. Vascular anastomoses (side-to-side, end-to-end, end-to-side) were carefully made by CO2 laser in the regions of the femoral arteries and veins, the carotid arteries and jugular veins in dog. A-C bypass was also successfully carried out between the internal mammary artery and the left anterior descending artery under the beating heart in experiment. Outputs of 20-40 mW and irradiation times of 6-12 sec/mm were optimal conditions for anastomosis of the small caliber vessels. There were no problems in the intensity and the healing of the anastomotic sites in comparison with the conventional suture method. On the basis of these excellent experimental results a low energy CO2 laser was employed clinically for vascular anastomosis of the peripheral vessels in 28 patients with angina pectoris or chronic renal failure and cardiac failure. There were no complications such as bleeding and suture line aneurysm after surgery. In conclusion, vascular anastomosis by laser might be recommended in performing with safety and rapidity for small caliber vessels.

Adult↗

PubMed1987