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Biomedical subjects

M Masaki

Publications and source records attributed to M Masaki.

At least 55 records · Page 3Linked to original sources
PubMed1988

Ototoxicity of Vasocidin drops applied to the chinchilla middle ear.

Some widely used ototopical preparations are potentially toxic to the middle and inner ear. Vasocidin Ophthalmic Solution (sulfacetamide sodium and prednisolone sodium phosphate) has been advocated as an alternative agent that may have fewer toxic side effects in the treatment of otorrhea. Vasocidin was introduced into the bullae of nine chinchillas to investigate the effects on the middle and inner ear. The organ of Corti and stria vascularis were found to be entirely normal in 17 of the 18 temporal bones studied. Changes observed in the middle ears at one week included inflammation, hemorrhage, and effusion. Examination of specimens at four weeks revealed resolution of most of the inflammatory changes. The results of this experimental study indicate that Vasocidin causes reversible middle ear inflammation with little or no toxic effect on inner ear structures.

Animals↗
PubMed1988

Effects of otic drops on chinchilla tympanic membrane.

Experimental studies have shown that if antibiotic otic drops reach the middle ear cavity they produce severe inflammation. However, the effects of these preparations on the tympanic membrane have not been thoroughly investigated. This study was designed to assess morphological changes in the chinchilla tympanic membrane two to 21 days after a single 0.2-mL application of an antibiotic otic preparation (Cortisporin Otic Suspension) to the middle ear cavity. At two days, the epidermal and the mucosal layers were destroyed. By four days, reepithelialization had occurred and all layers of the tympanic membrane subsequently became markedly hyperplastic. Disruption of the fibrous layer, invasion of keratinizing epidermis to the medial surface, and perforation were observed at three weeks. These findings indicate that tympanic membrane damage is a potentially significant aspect of the ototoxic properties of topical otic preparations.

Animals↗
PubMed1987

Increase in life expectancy at birth in Japan: some implications for variable patterns of decrease in mortality.

The characteristics of the increase in life expectancy at birth (eo) in Japan were analyzed using the life tables of developed countries in which the values of eo were almost the same. When the decrease in age-specific probability of dying (qx) and its contribution to total gain in eo in Japan were compared to those of other developed countries, the decline in qx in prime, middle and old age groups accounts for much of the change; the decrease in this variable for males aged 50 years and over accounted for 35% of the recent increase in eo. Well-organized medical care and public services are discussed in relation to this unique and unusually rapid increase in eo for the Japanese population.

Age Factors↗
PubMed1987

Increase in life expectancy at birth in Japan: some implications for variable patterns of decrease in mortality.

"The characteristics of the increase in life expectancy at birth...in Japan were analyzed using the life tables of developed countries in which the values of [life expectancy at birth] were almost the same. When the decrease in age-specific probability of dying...and its contribution to total gain in [life expectancy at birth] in Japan were compared to those of other developed countries, the decline in [age-specific probability of dying] in prime, middle and old age groups accounts for much of the change; the decrease in this variable for males aged 50 years and over accounted for 35% of the recent increase in [life expectancy at birth]. Well-organized medical care and public services are discussed in relation to this unique and unusually rapid increase in [life expectancy at birth] for the Japanese population."

Age Factors↗
PubMed1986

A new class of potent centrally acting muscle relaxants: pharmacology of oxazolidinones in rat decerebrate rigidity.

The severity of anaemic decerebrate rigidity was quantitatively determined by measuring the frequency of electromyographic potentials in the rat. Some oxazolidinones markedly reduced the severity of this decerebrate rigidity in a dose-dependent manner, (4S,5R)-4-(2-methylpropyl)-3- [3-(perhydroazepin-1-yl)propyl]-5-phenyl-1,3-oxazolidin-2-on e (MLV-6976) being the most potent. In addition to the oxazolidinones, an aminoalcohol derivative, (1RS,2SR)-5-methyl-1-phenyl-2-(3-piperidinopropylamino )hexan-1-ol (MLV-5860) also reduced the rat decerebrate rigidity. In the oxazolidinone series, the optical isomers with absolute configuration (S) at the 4-position were more potent than the corresponding (4R)-isomers, while there was no significant difference in their LD50 values. Normal rats and mice receiving MLV-6976 at doses which reduced decerebrate rigidity showed no behavioural changes, impairment of motor coordination only appearing at extremely high doses. MLV-6976 and its derivatives did not affect spinal reflex potentials in cats. MLV-6976 reduced the severity of harmaline-induced tremor in mice in a dose-dependent manner, but slightly augmented tremorine-induced tremor. The frequency of the spike discharges induced by iontophoretically applied glutamate was reduced by MLV-6976 in a dose-dependent manner in rat cortical neurones. The amplitude of miniature endplate potentials of the rat diaphragm was decreased by MLV-6976 only at concentrations greater than 0.1 mM. It is concluded that MLV-6976 acts on the brainstem or/and higher levels of the brain rather than on the spinal cord or the peripheral nervous system to reduce the excessive activities of the nervous system.

Animals↗
PubMed1986

Studies on Hanganutziu-Deicher antigens-antibodies. I. Hanganutziu-Deicher antibodies of IgG class in liver diseases.

Sera of patients with various liver diseases were examined for the presence of Hanganutziu-Deicher (H-D) antibodies by enzyme immunoassay with high-molecular weight glycoprotein (HMWGP) isolated from bovine red blood cell stromata. IgG class H-D antibodies were demonstrated in sera of 5.9% of acute hepatitis, 28.1% of chronic hepatitis and 21.9% of liver cirrhosis patients. H-D specificity of the antibodies under investigation was determined by absorption experiments. Evidence was also presented that the H-D antibodies in the liver disease sera are directed to N-glycolyl neuraminic acid (NGNA) and/or NGNA-dependent determinants of HMWGP.

Antibodies, Heterophile↗