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Biomedical subjects

M Haga

Publications and source records attributed to M Haga.

At least 109 records · Page 6Linked to original sources

Carcinogenic activity of Farfugium japonicum and Senecio cannabifolius.

The carcinogenicity of Farfugium japonicum and Senecio cannabifolius was studied in ACI rats. In Group I, rats were given a diet containing 20% Farfugium japonicum. Groups II, III, IV and V were given diets containing 8%, 4%, 1% and 0.2% Senecio cannabifolius until the end of the experiment, respectively. The experiment was terminated after 480 days, except for Group V which was terminated 560 days after the start of feeding. Hemangioendothelial sarcoma of the liver and liver cell adenoma were induced in Groups I, IV and V. All rats in Groups II and III died of hepatotoxicity within a short period.

Adenoma↗

Induction of mammary cancer in CD rats fed bracken diet.

Fifteen male and 15 female Charles River Sprague-Dawley rats (CD rats) of 6 weeks old were given a diet containing 30% bracken fronds throughout the experimental period of 260 days. Male rats fed bracken diet developed multiple ileal tumors and urinary bladder tumors with incidences of 100% and 60%, respectively. Female rats developed multiple mammary tumors with an incidence of 87% in addition to ileal and urinary bladder tumors. The earliest mammary tumor was detected on day 78, and the last on day 256. The average number of tumors per rat was 5.6. Most mammary tumors were papillary carcinomas and adenocarcinomas. No tumors were found in rats in the control group.

Adenocarcinoma↗

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↗

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↗