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Biomedical subjects

T Isawa

Publications and source records attributed to T Isawa.

5 recordsLinked to original sources
PubMed1979

Bronchogenic carcinoma producing ectopic steroid hormones.

A patient with steroid hormones or androgen producing bronchogenic adenocarcinoma was presented. Clinically he had a mediastinal mass and bilateral multiple pulmonary nodules which showed a rapid growth despite cancer chemotherapy. At postmortem examination, radioimmunoassay of the tumor tissue revealed androgen and their precursors. The mitochondria of the tumor cells resembled those of cells in the zona reticularis of the adrenal cortex.

Adult↗
PubMed1979

Effect of aminophylline on regional perfusion distribution in the lungs.

Using ten normal dogs, the right upper lobe of the lung was isolated in vivo by a balloon catheter and was artificially ventilated with nitrogen, air, 60% oxygen in nitrogen, and 60% oxygen and 20% carbon dioxide in nitrogen, while the rest of the lungs maintained a spontaneous breathing of ambient air. Aminophylline did not show a vasodilating action under severe alveolar hypoxia (PAO2: ca. 40 mmHg); on the contrary, it seemed to potentiate hypoxic pulmonary vasoconstriction. When the regional alveolar oxygen tension became less hypoxic (PAO2: ca. 70 mmHg) or higher than that in the rest of the lungs which spontaneously breathed ambient air, aminophylline showed a definite vasodilating action. Aminophylline also showed a vasodilating action in alveolar hypercapnia in the presence of alveolar hyperoxia.

Aminophylline↗
PubMed1978

Regulation of regional perfusion distribution in the lungs. Experimental model and effect of alveolar pressure.

An experimental model for studying changes in regional perfusion distribution in the lungs of a dog was described. The right upper lobe was separated in vivo from the rest of the lungs by a balloon catheter and gas exchange of the lobe was artificially done asynchronously with the rest of the lungs by using a gas of interest at a prescheduled aveolar pressure. 99mTc-albumin microsphere was the agent of choice for multiple sequential studies in one dog. Alveolar gas composition reached a plateau after the 4th inflation of the right upper lobe. Effect of alveolar pressure on regional perfusion distribution was studied by using nitrogen and air as exchange gases. Perfusion distribution in the right upper lobe was the least at the maximal alveolar pressure of 14 to 19 cm H2O, while it was the greatest at the tidal maximal alveolar pressure of 1 to-1cm H2O with either gas. Alveolar hyperinflation in a localized lung region due to the increase in regional alveolar pressure reduced regional perfusion distribution.

Air↗