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Biomedical subjects

M Osako

Publications and source records attributed to M Osako.

43 records · Page 3Linked to original sources

[Studies on the method of measurement of odorants dissolved in water--the simplified head space method].

An improved and simplified Head Space Method was devised for measurement of the concentration of odorants dissolved in waste water, and this method was examined to determine whether it was applicable for this purpose or not. This method is taken into consideration the variableness of liquid concentration and of gas pressure resulting from the volatilization of odorants and aqueous vapor to the atmosphere. By this method, the constants of hydrogen sulfide, dimethylsulfide and trimethylamine were measured under various temperatures and pHs. As a result of comparison with the measured values obtained by the Stripping Method and those from the heretofore used Head Space Method, this method appeared to be fairly applicable.

Hydrogen-Ion Concentration↗

[Measurements of hydrogen sulfide held in water and sludge in sewerage holes and the required amount of ventilation].

In Japan, it is required to measure the hydrogen sulfide (H2S) concentration before sewerage work can commence, in order to prevent toxic accidents caused by H2S. The actual H2S concentration of the sewerage hole is often different from that initially measured, and there is often a more than fatal concentration because of rapidly volatilizing H2S. However, no countermeasures for this have been developed, nor has any system for the measurement of the H2S held in sewerage water and sludge been established yet. In this paper, therefore, the measurement of H2S dissolved in water was investigated, and the actual form of the H2S held in the water and the sludge was analyzed. Prevention measures against toxic accidents were also investigated. Water and sludge were collected from an actual sewerage hole, and the quantities of H2S held in them were measured by the new method with the stripping which we developed. We also determined the quantity of H2S volatilized from the water surface during work, and estimated the change of air quantity necessary to reduce the concentration of H2S to a safety level for workers. As a result, it was shown that even if the H2S concentration of the gas phase before the work is regarded as at a safety level for workers, they may be in an extremely dangerous situation resulting from the rapid volatilization of H2S during their work.(ABSTRACT TRUNCATED AT 250 WORDS)

Hydrogen Sulfide↗

Botulinum A toxin (Oculinum) in ophthalmology.

Botulinum A toxin has been used to treat strabismus and a variety of spasmodic neuromuscular diseases. Botulinum toxin treatment of strabismus is not as definitive and stable as the traditional surgical approach, but it has been found most useful in postoperative overcorrection, small deviations, sensory deviations, and acute sixth nerve palsy. This toxin has been effective in the treatment of essential blepharospasm and hemifacial spasm, for which it produces temporary relief of symptoms. In addition, this treatment has been applied to lower lid entropion, myokymia, aberrant regeneration of the seventh nerve, lid retraction, corneal exposure, nystagmus, spasmodic torticollis, and adductor spastic dysphonia.

Blepharospasm↗

The characteristics of static visual fields in children with psychogenic visual disturbances.

PURPOSE: It is well-known that patients with psychogenic visual disturbances (PVD) exhibit characteristic kinetic visual fields. Even when the kinetic fields are normalized, the static fields of PVD children frequently remain abnormal. To verify this finding, we performed static perimetry on those children whose kinetic fields were initially normal or which normalized during the follow-up period, and compared the results with those of children with psychosomatic disorders (PSD) and normal children. METHODS: We examined 9 PVD children (17 eyes), 16 PSD children (32 eyes), and 16 normal children (16 eyes). Program 30-2 or 24-2 of the Humphrey Field Analyzer was used in the examinations on all subjects. RESULTS: The average mean deviation (MD) of the PVD group was significantly lower than that of the other groups (P <. 01). False negative errors and short-term fluctuations were significantly higher in the PVD group than in the other groups (P <. 05). CONCLUSION: Although PVD and PSD children possess a similar underlying psychological dysfunction, their performances in visual field testing proved to be quite different. In the PVD group, even when kinetic fields were normal, functional visual field loss in the static fields was common and had characteristic response properties.

Child↗

Comparison of detectability of visual field abnormality by frequency doubling technology in primary open-angle glaucoma and normal-tension glaucoma.

PURPOSE: To compare the effectiveness of frequency doubling technology (FDT) in detecting abnormalities in primary open-angle glaucoma (POAG) and in normal-tension glaucoma (NTG). METHODS: Twenty-nine POAG patients (29 eyes) and 27 NTG patients (27 eyes) were studied. All subjects underwent testing with program C-20 of FDT with appropriate corrective lenses. RESULTS: No significant differences were observed between the two groups in mean age, mean deviation (MD), and pattern standard deviation (PSD) measured by the Humphrey Field Analyzer (HFA). The correlation between MD values determined by HFA (x) and FDT (y) is represented by y = 0.60x - 2.7 (r = 0.78, P <.01) in the POAG group and y = 0.59x + 0.6 (r = 0.81, P <.001) in the NTG group. Although the average MD measured by FDT was significantly lower in the POAG group than in the NTG group (P <.05), no significant difference was found in average PSD between the two groups. In early glaucoma cases (MD > or = -5 dB by HFA), a larger proportion of cases in the POAG group than in the NTG group had lower significance level of MD determined by FDT than by HFA (P <.02). At many test points on the temporal periphery in the FDT, the mean sensitivity was lower in the POAG group than in the NTG group; whereas no significant differences among HFA test points were observed. CONCLUSIONS: Frequency doubling technology detected visual field abnormalities in POAG cases more sensitively than in NTG cases. This finding indicates that the pathogenesis of My-cell damage is rather different in POAG and NTG.

Glaucoma, Open-Angle↗

Effects of the Na+/H+ exchange inhibitor cariporide (HOE 642) on cardiac function and cardiomyocyte cell death in rat ischaemic-reperfused heart.

1. Na+/H+ exchange has been implicated in the mechanism of reperfusion injury. We examined the effects of the cardiac-specific Na+/H+ exchange inhibitor cariporide (HOE 642) on postischaemic recovery of cardiac function and cardiomyocyte cell death (i.e. necrosis and apoptosis). 2. Rat isolated and buffer-perfused hearts were subjected to 25 min normothermic global ischaemia followed by 120 min reperfusion. Cariporide (10 micromol/L) or its vehicle (0.01% dimethylsulphoxide) was administered for 15 min before ischaemia and for the first 30 min after reperfusion. 3. Cariporide significantly improved the recovery of isovolumic left ventricular function (heart rate, left ventricular developed pressure and left ventricular end-diastolic pressure) and coronary flow throughout reperfusion. Creatine kinase release during reperfusion was significantly less in the cariporide-treated heart. In situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL)-positive cardiomyocytes were also significantly less in the cariporide-treated heart after 120 min reperfusion. Electron microscopy showed necrotic changes without typical apoptotic features in cardiomyocytes after reperfusion. Such necrotic changes were mitigated by cariporide. Simultaneous detection of necrotic and apoptotic cardiomyocytes using propidium iodide (PI) and Annexin V revealed that cardiomyocytes in the infarct area were stained with only PI or both PI and Annexin V. Cariporide did not alter the pattern of cardiomyocyte staining with PI and Annexin V, although the number of cardiomyocytes stained with PI or PI plus Annexin V was less than that in vehicle-treated hearts. 4. These results suggest that apoptosis is not a major manifestation of cardiomyocyte cell death in the ischaemic-reperfused myocardium and a cariporide-sensitive mechanism of reperfusion injury promotes both necrotic and apoptotic processes of cell death.

Animals↗