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Biomedical subjects

H Ohara

Publications and source records attributed to H Ohara.

At least 73 records · Page 4Linked to original sources
PubMed1998

Clinical characteristics differentiating bacteriologically positive pulmonary tuberculosis patients from negative ones in Mongolia.

The objective of this study is to clarify clinical characteristics which differentiate bacteriologically positive pulmonary tuberculosis patients from negative ones in Mongolia. The subjects include 338 patients aged 16 years and older who had undergone bacteriological examinations. Of them, 107 patients (31.7%) were confirmed bacteriologically. The proportion of bacteriological positive results increased significantly among patients who had cavities in the roentgenographic examination, cough at diagnosis and the family history of tuberculosis. Addressing these clinical characteristics will contribute to raising not only the sensitivity of the sputum examination, but also the specificity of the roentgenographic examination in the diagnostic process of tuberculosis.

Adult↗
PubMed1998

Changes in immunological parameters after combination adjuvant therapy with intravenous DTIC, ACNU, and VCR, and local injection of IFN-beta (DAV + IFN-beta therapy) into malignant melanoma.

Combination adjuvant therapy with intravenous dimethyl triazeno imidazole carboxamide (DTIC), 1-[4-amino-2-methyl-5-pyrimidinyl]-methyl-3-[2-chloroethyl]-3-nitrosoure a hydrochloride (ACNU) and vincristine (VCR) and local injection of interferon-beta (IFN-beta) (DAV + IFN-beta therapy) has been widely applied to treat malignant melanoma, and its therapeutic effect is accepted in Japan. Natural killer (NK) activity, CD4+ and CD8+ T cell counts, CD4/CD8 ratio, and white blood cell counts were analyzed before and after DAV + IFN-beta therapy in order to validate its efficacy. After DAV + IFN-beta therapy, the CD4/CD8 ratio was elevated; however, numbers of both CD4+ and CD8+ T cells and NK activity were consecutively depressed. Peripheral lymphocytes were also decreased, possibly by myelosuppression due to the DAV therapy. The posttreatment suppression of NK activity appeared in spite of the administration of IFN-beta. It is suggested that a more effective adjuvant immunomodulator should be introduced to improve the therapeutic effect of the combination adjuvant chemotherapy in malignant melanoma.

Adult↗
PubMed1997

Laparoscopic-assisted colon surgery by abdominal wall lifting with newly developed lifting bars.

BACKGROUND: The aim of the study is to evaluate the efficacy of laparoscopic-assisted colon surgery by lifting the abdominal wall with newly developed lifting bars. METHODS: We have made and used two kinds of lifting bars: type I and type T. Two I-type lifting bars are used in transverse colectomy and right hemicolectomy. One I-type lifting bar and one T-type bar are used in sigmoid colectomy and low anterior resection. After the intestine is dissected and the mesenterium is treated under laparoscopy, a small laparotomy wound about 4 to 6 cm long is made, and the intestine is pulled out of the body for extracorporeal anastomosis. RESULTS: The mean operating time was 153.8 +/- 51.9 min, and no particular complications were noted. CONCLUSIONS: Since postoperative pain is mild and postoperative recovery is rapid, this method is considered to be an effective surgical procedure.

Abdominal Muscles↗
PubMed1997

Interleukin-6 is a useful marker for early prediction of the severity of acute pancreatitis.

Twelve patients with acute pancreatitis admitted to our department between January 1993 and December 1994 were studied prospectively and classified into two groups (severe group, five patients; mild group, seven patients), according to the criteria for grading severity of acute pancreatitis proposed by the Research Committee for Intractable Diseases of the Pancreas, Japanese Ministry of Health and Welfare (1990). To evaluate markers for early estimation of the severity of acute pancreatitis, we measured serum changes in various parameters. In the severe group interleukin-6 (IL-6) levels were increased significantly 5, 24, 72, and 120 h after the onset (p < 0.01), compared with the mild group. C-reactive protein (CRP), thrombin antithrombin III, and alpha 2-plasmin inhibitor plasmin complex levels were significantly increased only at the 72-h time point. Peak values of interleukin-8 (IL-8) and soluble human E selectin were observed at 5 and 72 h, respectively, after the onset. There was a significant correlation between IL-6 at 5 h and both pancreatic secretory trypsin inhibitor (r = 0.85) and CRP (r = 0.94) at 72 h. We therefore conclude that IL-6 is a useful marker for assessment of the severity of acute pancreatitis in its early stages.

Acute Disease↗
PubMed1997

Differing influence on delays in the case-finding process for tuberculosis between general physicians and specialists in Mongolia.

The objective of this study is to compare the influence on delays in the tuberculosis case-finding process according to the types of medical facilities initially visited. The subjects include 107 patients 16 years and older who were diagnosed with bacteriologically confirmed pulmonary tuberculosis at nine tuberculosis specialized facilities in Ulaanbaatar, Mongolia from May 1995 to March 1996. Patients were interviewed about their demographic and socioeconomic factors and their medical records were reviewed for measuring delays. Fifty-five patients initially consulted general physicians and the remaining 52 patients initially visited other types of facilities including tuberculosis specialized facilities. Patients who initially consulted general physicians had shorter patient's delays and longer doctor's delays than those who had visited other facilities first. Since the reduction of patient's delay outweighs the extension of doctor's delay among patients who initially consulted general physicians, their total delay was shorter than that of patients who visited other facilities first. The beneficial influence of consulting general physicians first on the total delay was observed after adjusting for patient's age, sex, residence area, family income and family history of tuberculosis. This finding indicates that general physicians play an important role in improving the passive case-finding process in Mongolia.

Adolescent↗
PubMed1997

A follow-up study of preventive effects on low back pain at worksites by providing a participatory occupational safety and health program.

Low back pain is still a common and serious issue at worksites. In order to evaluate preventive effects on low back pain by providing a participatory occupational safety and health program, we conducted a 10 year follow-up study at the Tokyo Metropolitan Bureau of Waste Management and examined yearly changes in the number of compensated and claimed low back pain. The participatory occupational safety and health program is based on a small-sized group and joint employee-employer involvements. This program includes analysis of occupational accidents, revision of the safety procedure manual, participatory training classes, improving and evaluating working procedures and personal protective equipment , and so on. The number of compensated low back pain from 1984 to 1994 has decreased from 318 to 87, and the number of claimed low back pain has decreased from 343 to 92. These results suggest that the participatory occupational safety and health program is effective in prevention of low back pain.

Follow-Up Studies↗
PubMed1997

Prophylaxis of acute viral hepatitis by immune serum globulin, hepatitis B vaccine, and health education: a sixteen year study of Japan overseas cooperation volunteers.

From 1978 to 1993 a study of acute viral hepatitis contracted by the Japan Overseas Cooperation Volunteers (JOCV) during their assignments in tropical and subtropical countries was conducted. Of 10,509 subjects in this study, 240 cases of acute viral hepatitis were confirmed (hepatitis A = 139, hepatitis B = 72, and non-A, non-B hepatitis = 29). The annual morbidity was 5.1% in 1978 and 4.9% in 1979, with hepatitis A accounting for 80% of the cases. However, it decreased significantly after the prophylactic inoculation with immune serum globulin (ISG) was started in 1980. A significant decrease of hepatitis B from 1.2% in 1980 to 0.1% in 1990 was also seen after vaccination was introduced for all volunteers in 1988. Health education concerning food and water sanitation, and providing general information on viral hepatitis, was also conducted throughout this period. These results indicate that acute viral hepatitis could be successfully prevented in the JOCV with a combination of ISG, hepatitis B vaccination, and health education.

Acute Disease↗
PubMed1997

Irradiation of mixed beam and design of spread-out Bragg peak for heavy-ion radiotherapy.

Data on cellular inactivation resulting from mixed irradiation with charged-particle beams of different linear energy transfer (LET) are needed to design a spread-out Bragg peak (SOBP) for heavy-ion radiotherapy. The present study was designed to study the relationship between the physical (LET) and biological (cell killing) properties by using different monoenergetic beams of 3He, 4He and 12C ions (12 and 18.5 MeV/nucleon) and to attempt to apply the experimental data in the design of the SOBP (3 cm width) with a 135 MeV/nucleon carbon beam. Experimental studies of the physical and biological measurements using sequentially combined irradiation were carried out to establish a close relationship between LET and cell inactivation. The results indicated that the dose-cell survival relationship for the combined high- and low-LET beams could be described by a linear-quadratic (LQ) model, in which new coefficients alpha and beta for the combined irradiation were obtained in terms of dose-averaged alpha and square root of beta for the single irradiation with monoenergetic beams. Based on the relationship obtained, the actual SOBP designed for giving a uniform biological effect at 3 cm depth was tested with the 135 MeV/nucleon carbon beam. The results of measurements of both physical (LET) and biological (90% level of cell killing, etc.) properties clearly demonstrated that the SOBP successfully and satisfactorily retained its high dose localization and uniform depth distribution of the biological effect. Based on the application of these results, more useful refinement and development can be expected for the heavy-ion radiotherapy currently under way at the National Institute of Radiological Sciences, Japan.

Animals↗
PubMed1997

Laparoscopic surgery by abdominal wall lifting using original lifting bars.

Laparoscopic surgery by abdominal wall lifting may be less invasive than by pneumoperitoneum, because the influence of the pneumoperitoneum can be avoided. We have performed laparoscopic surgery without pneumoperitoneum by lifting the full layer of the abdominal wall using two unique kinds of lifting bars that we developed. We have used this method on a total of 154 patients and obtained favorable results. Laparotomy was performed in three of the 104 patients undergoing cholecystectomy. All of them had previously undergone gastrectomy, and laparotomy was performed because of severe intraperitoneal adhesions. There were no severe complications, but insufficient suturing was experienced in one patient who underwent resection of the large intestine. In this article we describe the procedures and results of the lifting method.

Abdominal Muscles↗
PubMed1997

[A study of waste anesthetic gases monitoring and working environmental controls in hospital operating rooms].

There are hazardous factors threatening health care workers, and many hazardous chemical substances have been reported in operating rooms, central supply facilities, laboratories and so on. In Japan, little attention has been paid to exposure to these chemicals and to working environmental controls. Waste anesthetic gases are chemicals concerned, and we conducted environmental monitoring continuously and measured exposure to nitrous oxide, isoflurane and sevoflurane in operating rooms, and examined working environmental controls. The average environmental concentrations of nitrous oxide were about 400 ppm in anesthetists' working areas, and about 180 ppm in surgeons' and instrument nurses' working areas under unscavenged conditions. Under scavenged conditions, environmental concentrations were 70-190 ppm in anesthetists' zones, and 70-90 ppm in surgeons' and instrument nurses' zones. Even under scavenged conditions, operating room personnel are presumed to be exposed to high concentrations of nitrous oxide above ACGIH's TLV and NIOSH's REL. The level of exposure of isoflurane and sevoflurane was 2-4 ppm. Managing general ventilation system and airflow direction, working area under scavenged system, environmental concentration levels of nitrous oxide could be reduced to 20-30 ppm. In order to control occupational exposure to anesthetic gases, it is not sufficient to merely adapt scavenging systems in operating rooms. Working environmental control and occupational hygiene management should be required.

Air Pollutants, Occupational↗
PubMed1997

Laparoscopic Hill's vagotomy by the abdominal wall lifting method.

We performed laparoscopic Hill's vagotomy by the abdominal wall lifting method in nine patients with intractable duodenal ulcer. Our original I-type lifting bar is a curved stainless-steel rod 5 mm in diameter. One I-type lifting bar is inserted intraperitoneally into each of the right and left hypochondrial regions. An incision is made in the lesser omentum near the gastroesophageal junction, and the right esophageal wall and right crus of the diaphragm are dissected and exposed. The posterior trunk of the vagus nerve is identified and divided. Then the neurovascular bundle is dissected and divided repeatedly along the lesser curvature of the stomach from the first branch of the crow's foot to the gastroesophageal junction. The mean operating time was 163 min, with little blood loss. The reduction rate of basal acid output and maximal acid output was, respectively, 73.7 +/- 0.1 and 63.7 +/- 0.1%. Four weeks after surgery, gastroduodenoscopy revealed ulcer healing to a scar.

Adult↗
PubMed1996

The role of DNA repair on cell killing by charged particles.

It can be noted that it is not simple double strand breaks (dsb) but the non-reparable breaks that are associated with high biological effectiveness in the cell killing effect for high LET radiation. Here, we have examined the effectiveness of fast neutrons and low (initial energy = 12 MeV/u) or high (135 MeV/u) energy charged particles on cell death in 19 mammalian cell lines including radiosensitive mutants. Some of the radiosensitive lines were deficient in DNA dsb repair such as LX830, M10, V3, and L5178Y-S cells and showed lower values of relative biological effectiveness (RBE) for fast neutrons if compared with their parent cell lines. The other lines of human ataxia-telangiectasia fibroblasts, irs 1, irs 2, irs 3 and irs1SF cells, which were also radiosensitive but known as proficient in dsb repair, showed moderated RBEs. Dsb repair deficient mutants showed low RBE values for heavy ions. These experimental findings suggest that the DNA repair system does not play a major role against the attack of high linear energy transfer (LET) radiations. Therefore, we hypothesize that a main cause of cell death induced by high LET radiations is due to non-reparable dsb, which are produced at a higher rate compared to low LET radiations.

Animals↗
PubMed1996

Interrelations between sympathoadrenal system and hypothalamo-pituitary-adrenocortical/thyroid systems in rats exposed to cold stress.

The interrelations between sympathoadrenal (SA) system and hypothalamo-pituitary-adrenocortical (HPA) or hypothalamo-pituitary-thyroid (HPT) system during cold stress were examined by measuring plasma levels of dihydroxyphenylalanine (DOPA), catecholamine and their metabolites in adrenalectomized (ADX) and thyroidectomized (TX) rats exposed to cold stress (-3 degrees C). Plasma levels of adrenocorticotropic hormone (ACTH), corticosterone (CORT), thyroid-stimulating hormone (TSH) and thyroid hormones in cold-stressed rats were measured also. Plasma ACTH levels were increased transiently after 1 h of cold exposure, after which the circadian rhythm and plasma levels of ACTH were similar to those of normal rats. Plasma CORT levels were also elevated after 1 h of cold exposure; the increased levels of CORT tended to return to normal levels after 9 h of cold, but remained higher than those of normal rats during at least 24 h of cold exposure. Plasma ACTH levels of 5 day cold-stressed rats were no longer elevated above those of control rats and plasma CORT levels were only slightly higher than in control animals. However, plasma levels of TSH and free thyroid hormones were elevated after 1 day and remained elevated after 5 days of cold exposure. Thus, cold stress appears to activate chronically the HPT system, but only transiently activates the HPA system. ADX rats had higher basal plasma levels of dihydroxyphenylglycol (DHPG), methoxyhydroxyphenylglycol (MHPG), DOPA and homovanillic acid (HVA) than those of sham-operated (SHAM) rats, but norepinephrine (NE) levels were not significantly greater than in SHAM animals. TX rats had higher basal plasma levels of NE, epinephrine (EPI) and dopamine (DA), as well as much higher plasma levels of the metabolites. Exposure to cold increased plasma NE levels in both ADX and TX rats, but the increments in TX rats were much greater than in SHAM and ADX groups. Plasma EPI levels were not significantly elevated during cold exposure in SHAM rats, but were highly elevated in TX rats exposed to cold. TX rats had much larger increments in plasma levels of DHPG, MHPG, DA, dihydroxyphenylacetic acid (DOPAC) and HVA during cold exposure than those of SHAM and ADX rats. These results are consistent with the view that endogenous glucocorticoids restrain responses of catecholamine synthesis, release, reuptake, and metabolism in sympathetic nervous system of cold-stressed animals, but that in the absence of an effective HPT system, there is enhanced sympathoadrenal medullary function and augmentation of their responses to cold as a means for maintaining body temperature when the HPT thermogenesis system is impaired.

Adrenal Glands↗
PubMed1996

Effects of continuous and intermittent cold (SART) stress on sympathoadrenal system activity in rats.

We compared sympathoadrenal responses to intermittent cold (SART) stress (in which cold exposure is interrupted by 4-hourly intervals daily at room temperature) with those to continuous cold (-3 degrees C) stress. Plasma levels of dihydroxyphenylalanine (DOPA), catecholamines and their metabolites as well as tyrosine hydroxylase (TH) activities in sympathetically innervated tissues were examined in rats exposed to each stressor for 1 day or for 5 days. Neither SART nor continuous exposure to cold for 1 day or 5 days altered plasma epinephrine (EPI) levels. However, norepinephrine (NE) and dihydroxyphenylglycol (DHPG) levels increased markedly during exposure to these stressors. On the first day of SART or continuous cold stress, NE levels were increased similarly, but the increments in DHPG levels were greater during SART stress. Since DHPG is formed in neurons, neural reuptake of NE may be more enhanced on the first day of SART stress than on the first day of continuous cold stress. After 5 days of SART stress plasma NE levels were significantly higher than those found after 5 days of continuous cold exposure. Plasma levels of DHPG were elevated to the same extent in both 5 days SART- and continuously cold-stressed rats, whereas plasma levels of methoxyhydroxyphenylglycol (MHPG) increased only by 5 days SART stress. Even at 1 h after the removal from 5 days SART stress, increased plasma levels of NE, DHPG and MHPG were still evident. These results suggest that 5 days SART stress elevates extraneuronal O-methylation of DHPG, and that NE turnover is more greatly increased by SART stress than by continuous cold stress. Plasma levels of DOPA, dopamine, dihydroxyphenylacetic acid and homovanillic acid also increased after either SART or continuous cold stress for 1 day and 5 days. Adrenal TH activities were significantly increased in rats exposed to SART or continuous cold stress for 1 day and 5 days, but in brown fat TH activity was elevated only in rats exposed to 5 days of continuous cold. Both SART and continuous cold stress are selective and potent stimuli for activation of the sympathoneural system, apparently without significant adrenomedullary EPI release. The increase of TH activity in the brown fat pad as well as of plasma NE and its metabolites is probably a result of adaptation to cold. It appears that even short intervals of return to a normal environmental temperature, as in SART, are sufficient to diminish sympathetic adaptation to cold.

3-Methoxy-4-hydroxyphenylethanol↗
PubMed1996

NAD-specific 6-phosphogluconate dehydrogenase in lactic acid bacteria.

6-Phosphogluconate dehydrogenase was screened in for cell-free extracts from seventeen strains of lactic acid bacteria. Three types of the enzyme could be classified according to the coenzyme specificity: NAD-specific, NADP-specific, and non-specific types. The two strains that had a heterofermentative pathways had an NAD-specific 6-phosphogluconate dehydrogenase. This type had higher enzyme activity per proteins in the cell-free extracts, and more specificity to NAD compared to the other types of the enzyme in the lactic acid bacteria studied.

Cell-Free System↗
PubMed1996

Detection of Auger enhancement induced in HeLa cells labeled with iododeoxyuridine and irradiated with 150 kV x-rays--Effects of cysteamine and dimethylsulfoxide.

We examined the effects of cysteamine and dimethylsulfoxide on the lethality of iododeoxyuridine-labeled HeLa cells irradiated with 150 kV x-rays (effective energy was 48 keV) and compared with those irradiated with 60Co gamma-rays. The protectable fraction was estimated from the regression lines for the reciprocal plots of the concentration of protectors, versus the degree of protection. The protectable fraction by cysteamine was 9.4% lower in iododeoxyuridine-labeled cells than in control cells when they were irradiated with x-rays, whereas no such difference was observed with dimethylsulfoxide. The slopes of the regression lines were steeper (i.e., more difficult to protect) for both protectors in iododeoxyuridine-labeled cells irradiated with x-rays. No such differences were observed in gamma-irradiated cells. The cause for these differences are attributable to Auger enhancement. The results suggest that at least a portion of Auger enhancement is not protectable by cysteamine and is hard to be protected by both protectors cysteamine and dimethylsulfoxide.

Cell Survival↗
PubMed1996

Single application extracorporeal shock wave lithotripsy is the first choice for patients with pancreatic duct stones.

OBJECTIVES: We performed extracorporeal shock wave lithotripsy (ESWL) as the treatment of first choice on 32 chronic pancreatitis patients with main pancreatic duct (MPD) stones prospectively to establish more convenient and safer treatment. METHODS: All patients were treated in a prone position, and shock waves were discharged from the ventral side. ESWL was performed once or twice a week, and no other treatments before ESWL had been applied. RESULTS: Disintegration of all MPD stones to 3 mm or less in diameter could be achieved in all treated patients. Complete clearance of the stones was obtained in 24 patients (75%) without the necessity of endoscopic extraction of fragments. Reduction of MPD diameters after ESWL was statistically significant (p < 0.01). Epigastric and/or back pain complaints before ESWL were completely alleviated in 79% (periods of follow-up: 16-63 months, mean 44), and the pancreatic exocrine function also improved in 61%. No severe complications occurred in any of the patients. CONCLUSIONS: ESWL, which is comparatively easy to perform, is a safe and efficient approach that changes endoscopy's status as an indispensable pretreatment. Therefore, ESWL can be recommended as the first choice treatment for patients with chronic pancreatitis accompanied by MPD stones that should be tried before consideration of either surgical or endoscopic procedures.

Adult↗