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Biomedical subjects

M Sakata

Publications and source records attributed to M Sakata.

At least 217 records · Page 12Linked to original sources
PubMed1984

Lymphocyte locomotion in experimental allergic thyroiditis.

Experimental allergic thyroiditis was produced in rats by immunization with homologous thyroglobulin (Tg). The mechanisms of lymphocyte accumulation of the thyroid lesion were analyzed by using this experimental model. The sensitized lymph node cells were cultured with Tg. After 72 hr, the cell-free supernatant was found to contain a chemotactic factor for sensitized lymphocytes. Lymph node lymphocytes from animals immunized 3 weeks previously were the best source of such sensitized lymphocytes while the cells at the latter stage could not produce the factor. The culture supernatant was applied to a Sephadex G-100 gel filtration column. The results indicate that the molecular weight of the factor is around 12,400. Among lymph node lymphocytes, nylon-wool column nonadherent lymphocytes were the most responsive; adherent lymphocytes were not responsive. Thyroglobulin itself did not chemoattract lymphocytes obtained from rats immunized with Tg. This phenomenon was in contrast to macrophage chemotaxis in the same model in which macrophage itself can move toward Tg. In any event, these results seem to indicate that a chemotactic lymphokine may be playing an important role in the pathogenesis of lymphocyte accumulation of the thyroid lesion.

Animals↗
PubMed1982

A new method for evaluating mucolytic expectorant activity and its application. II. Application to two proteolytic enzymes, serratiopeptidase and seaprose.

Using our new method described in a preceding paper, in vivo effects of two proteolytic enzymes such as serratiopeptidase (SER) and seaprose (SAP) on sputa collected from bronchitis rabbits were examined. SER (20 mg/kg) and SAP (30 mg/kg) significantly reduced the viscosity of sputum (P less than 0.05) at the 1-3-h periods and the 4-6-h periods, respectively, after intraduodenal administration. 50 mg/kg of SER also significantly decreased not only viscosity (P less than 0.001) but also amount of freeze-dried substance (P less than 0.05) of sputum at the 1-3-h periods, but SAP did not affect the amount of dried substance. Both enzymes significantly increased the volume of sputum, probably as the result of liquefaction. Thus, mucolytic expectorant activity of both enzymes can be demonstrated first by the reduction in viscosity and next of the increase in volume of sputa. However, the decrease in amount of freeze-dried substance is not always in accord with the reduction viscosity.

Animals↗
PubMed1982

Methemoglobin in blood as determined by double-wavelength spectrophotometry.

We describe spectrophotometric determination of methemoglobin (Met-Hb) in blood by absorbance differences at two wavelengths (characteristic of the instrument used) in the 500-600 nm region. Blood is diluted 100- to 200-fold with a solution containing KCN and carbon monoxide to convert hemoglobin to carboxyhemoglobin and Met-Hb to cyanomethemoglobin (CN-Met-Hb). Carboxyhemoglobin has the same absorbance at the two wavelengths used, so that the differences in absorbance reflect only the CN-Met-Hb component. After measurement of absorbance differences, potassium ferricyanide is added to convert all hemoglobin derivatives to CN-Met-Hb; samples are then remeasured at the same wavelengths. The percentage of Met-Hb is determined from the ratio of the absorbance differences. Results agree satisfactorily with currently accepted procedures and with calculated theoretical results for mixtures of oxyhemoglobin, carboxyhemoglobin, and Met-Hb.

Carboxyhemoglobin↗
PubMed1982

A new method for evaluating mucolytic expectorant activity and its application. I. Methodology.

A new method for evaluating in vivo effect of mucolytic expectorants was devised. In this report, however, the focus is placed on methodology but not on pharmacology. Rabbits with subacute bronchitis were prepared by long-term exposure to minute amounts of SO2 gas. The sputum was quantitatively collected from the animal through a tracheal cannula at suitable time intervals according to the Perry and Boyd's method. As a preliminary study, changes in volume, viscosity and amounts of freeze-dried substance of sputa were examined after intraduodenal administration of water instead of mucolytic expectorants, the effects of which will be described in the subsequent paper, but no significant changes occurred with this test.

Animals↗
PubMed1981

Modification of low virulent Newcastle disease virus infection in chickens infected with reticuloendotheliosis virus.

One-day-old SPF chicks were inoculated with reticuloendotheliosis virus (REV) which had been isolated from contaminated Marek's disease vaccine. Then they were subjected to super infection with the B1 or TCND strain of Newcastle disease virus (NDV) and examined for virus recovery, antibody response and the appearance of symptoms. Regardless of the time, from 0 to 8 weeks, of inoculation with the NDV-B1 strain after the REV infection, the antibody response was suppressed and the duration of the NDV recovery prolonged. Specific death preceded by severe respiratory or neural signs occurred more frequently to chicks inoculated with REV than to uninoculated controls after inoculation with the NDV-B1 strain in the neonatal stage or with the NDV-TCND strain at 5 weeks of age.

Animals↗
PubMed1980

Rapid determination of carboxyhemoglobin by absorbance difference between double wave length.

A spectrophotometric determination of CO-Hb content was investigated on the basis of double wavelength spectrophotometry. Absorbance differences at the two wavelengths at which O2-Hb has the same absorbance reflect only the CO-Hb component because the O2-Hb component is nulled out from the mixture of O2-Hb and CO-Hb. After measurement of absorbance difference, the measuring solution was saturated with pure CO and remeasured. CO-Hb % was calculated from the ratio of the absorbance differences. Since temperature significantly influences the spectrum of hemoglobin pigment, the wavelength pair changed with temperature. For accurate measurement, it was necessary to control temperature of diluting solution before dilution. Liberation of CO fro CO-Hb was observed at more than 80% CO-Hb, and 5% and 2% liberation from 100% CO-Hb occured at 100-fold dilution with 10 mm cuvette and 20-fold dilution with 2 mm cuvette respectively. Advantages of this method are that the standard curve or equation for calculation and accurate dilution are not necessary because the interfering component is nulled out and 100% CO-Hb of the standard sample is made with the same sample; and measurement is very rapid, taking less than 2 min.

Absorption↗
PubMed1980

Determination of carbon monoxide in blood by head space analysis.

A method for the determining the amount of carbon monoxide (CO) in blood is described. CO bound to hemoglobin is released with potassium ferricyanide into a known volume of head space of a disposable syringe. Vapor in the head space is withdrawn with a gastight microcyringe and injected into the gas chromatograph. CO dissolved in saturated blood is also measured by head space analysis to ascertain that dissolved CO is able to be removed with only one shaking of blood with nitrogen (N2). N2 put into the head space previously is used as internal standard. The advantages of this method lie in the ease and speed of operation with a simple and widely available instrument.

Carbon Monoxide↗
PubMed1980

Pharmacological evaluation of OP 1206, a prostaglandin E1 derivative, as an antianginal agent.

Effects of OP 1206 were studied on the cardiovascular system and platelet functions to assess OP 1206 as an antianginal agent. OP 1206 given orally at more than 100 micrograms/kg relieved vasopressin-induced ST depression of rat electrocardiogram (ECG), an animal model of angina pectoris, concomitant with slight hypotension. Intra-coronary injection of OP 1206 (1-100 ng/kg) in dogs resulted in a remarkable increase of coronary blood flow without any influence on heart rate, blood pressure, myocardial oxygen consumption and redox potential. Resistance in both large and small vessels of dog coronary artery was decreased by intravenous injection of OP 1206 (1-3 micrograms/kg). Platelet aggregation, adhesiveness, bleeding time, and thrombocytopenia induced by ADP and collagen infusion in guinea-pigs were inhibited by oral administration of OP 1206 at the same doses or doses less than those relieving vasopressin-induced ST depression of ECG. These results suggest that OP 1206 contributes to the improvement of cardiac imbalance between oxygen demand and supply, and suppression of thrombus formation in atherosclerotic heart.

Alprostadil↗
PubMed1977

[Pharmacological studies on expectorants (author's transl)].

Perry and Boyd's method described in 1941 appears to be the most suitable for evaluating the efficacy of expectorants. In this method, changes in volume of respiratory tract fluid (RTF) collected by postural drainage from animals breathing air kept at a constant temperature and humidity are used as criteria. We attempted to improve on the method and to establish the optimum experimental conditions for rabbits. Accordingly, an air conditioning apparatus and tracheal cannula were re-designed and basic experimental conditions essential for quantitative collection of RTF were studied. Using this method, the effects of drugs on the volume of respiratory tract fluid (VRTF) were determined. Bromhexine and emetine as expectorants increased VRTF, and the former showed far more remarkable effects. Codeine and dextromethorphan as antitussives, isoproterenol, clorprenaline and C-78 as bronchodilators decreased VTRF. On the other hand, fominoben and eprazinone as antitussives increased VRTF. Our findings with application of this new approach indicate that this method is applicable for evaluating not only the efficacy of expectorants which increase VRTF but also that of other drugs which decrease VRTF.

Animals↗