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Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 1,117 records · Page 62Linked to original sources

[Changes in pulmonary function after bilateral lung resection].

Recently, bilateral lung resection are often performed as a treatment of both sides of emphysematous bullae or metastatic lung tumor. In our studies, general status and pulmonary function after the surgery were well maintained in most patients treated with partial lung resection or bullectomy. However, in cases received the resection of three or more segments on both side of the lung, vital capacity after the second surgery decreased in greater degree than was expected from the total volume of lung removed, and their Hugh-Jones grades for dyspnea proceeded postoperatively to II degrees or III degrees. Postoperative disturbance in pulmonary function is an important problem in cases of bilateral lung resection in numbers of segments. We studied experimentally on changes of pleural pressure and pressure-volume curve (P-V curve) of the remaining lung lobe and chest wall after bilateral lobectomy. Pleural pressure became more subatmospheric following the lobectomies, i.e., the functional residual capacity of the remaining lobe increased. The compliance of the remaining lobe decreased after lobectomies and the P-V curves were shifted to the right, resulted in decrease of the lung volume under the condition of a high grade of inspiration, i.e., reducing vital capacity.

Adult↗

[Meningioma and acoustic neurinoma occurring in two siblings of two different families].

The authors reported familial brain tumors in which meningioma and acoustic neurinoma occurred in two siblings of each two families with no evidence of the neurocutaneous syndromes, nor the familial cancer syndromes. Case A-1 is a 49-year-old female admitted to the hospital because of bilateral visual disturbance in July of 1976. A suprasellar mass was observed by CT scan. Right frontal craniotomy and removal of the tumor were done in July of 1976. Histological diagnosis was meningothelimatous meningioma. Case A-2 is a 47-year-old female, a younger sister of case A-1. Tinnitus, hearing disturbance, hemifacial sensory involvement of right side and impaired gait occurred at the end of 1981. Tomography revealed the dilatation of the right internal auditory canal. A multicystic mass was observed at the right cerebellopontine angle by CT scan. An operation was performed in May of 1982, and the tumor was diagnosed as Antoni A type neurinoma. Case B-1 is 23-year-old male who was admitted to the hospital in April of 1975, following the sudden onset of general convulsion. Left carotid angiogram showed the elevation of middle cerebral arteries and a tumor stain at the left temporal region. An operation was performed to remove the left sylvian tumor in April of 1975, and the tumor was diagnosed as transitional meningioma. Case B-2 is a 32-year-old female, an elder sister of case B-1. Bilateral tinnitus and hearing disturbance occurred in 1973. She complained left hemifacial sensory involvement and impaired gait in July of 1979. CT scan showed mass lesions with markedly contrast enhancement effect at the bilateral cerebellopontine angles. An operation was performed to remove the left tumor in November of 1979 and the right tumor in July of 1980. Histologically the both tumors were diagnosed as Schwannoma. The authors have collected reports of 117 families in which intracranial tumors occurred without evidence of the neurocutaneous syndromes and the familial cancer syndromes. Six out of 117 families showed histologically different kind of tumors, however the combination of meningioma and neurinoma could not be found. Consequently our cases of meningioma and neurinoma occurred in two siblings of two different families must be the first report.

Adult↗

[Stromal sarcoma of the male breast].

A 63-year-old man who had been aware for 5 years of a tumor near his left nipple was admitted complaining of rapid tumor enlargement. He received standard mastectomy under the diagnosis of breast sarcoma. The regional lymph nodes were not involved and the excised tumor was 12.0 cm in diameter it showed a grayish-white cut surface and a sharp border. Histologically we made a diagnosis of stromal sarcoma of the breast showing diffuse proliferation of spindle shaped cells with high cellularity, moderate atypia and scattered mitosis. Postoperatively, he underwent chemotherapy with cyclophosphamide. Two years and five months after the operation, he is alive and well without any sign of recurrence.

Breast Neoplasms↗

Experimental pendulum air in the flail chest.

Conditions for occurrence of pendulum airflow under spontaneous ventilation were studied in adult dogs with flail chest experimentally constructed by removing three ribs and the chest wall. Pendulum air flow was recorded pneumotachometrically from outside the body by intubation to the bronchi. Despite objections to the occurrence of pendulum air by many investigators, we found that pendulum airflow occurs under various conditions. The main factors facilitating the occurrence included 1) Significant differences in airway pressure and ventilatory volume between the lungs on the injured and the opposite side. 2) A high frequency of respiration. 3) Increased resistance in the upper airway. The pendulum airflow occurred not only at the area of tracheal bifurcation but also in the peripheral bronchial airway in the ipsi-lateral thorax of the flail chest. However, pendulum airflow was observed only transiently coinciding with the time of change from one phase of respiration to the other, and volume of pendulum airflow was considered to be so minimal that it had no significant deleterious influence on the alveolar ventilation. In cases of marked dysfunction of the chest wall or with increasing upper airway resistance, pendulum airflow may disturb alveolar ventilation to a considerable extent.

Airway Resistance↗

Biphasic action of platelet-activating factor on isolated guinea-pig ileum.

1-0-Hexadecyl-2-0-acetyl-sn-glycero-3-phosphocholine (platelet-activating factor) at 10(-10)-10(-9) M induced slow contraction of isolated guinea-pig ileal muscles and the contraction persisted for a long time. At a higher concentration of 10(-7) M, this phospholipid induced more rapid, but not greater, contraction. At higher concentrations (10(-6)-10(-5) M), this phospholipid induced a biphasic response: rapid contraction followed by relaxation. At high concentrations, this compound inhibited acetyl-choline-induced contractions. The stimulatory effect of this phospholipid was ca. 300 times that of 1-palmitoyl-2-0-acetyl-sn-glycero-3-phosphocholine, while its inhibitory potency on induced contraction was similar to those of 1-palmitoyl-2-0-acetyl-sn-glycero-3-phosphocholine and its lyso derivative. It was suggested that the differences in effects on contraction of different concentrations of 1-0-hexadecyl- and 1-palmitoyl-2-0-acetyl-sn-glycero-3-phosphocholine were due to the effects of these compounds on the ileum: a strong stimulatory effect and a moderate inhibitory effect on contraction.

Animals↗

Studies of the mechanisms of gastric bleeding under obstructive jaundice. Role of biogenic amines.

Mechanisms of gastric bleeding under obstructive jaundice were studied in adult male Wistar rats. Following ligation of the common bile duct, mucosal noradrenaline significantly decreased in both the pyloric and fundic gland areas of the gastric mucosa by 20 days after the operation. Serotonin increased only in the pyloric gland area, and histamine increased in the fundic gland area. Urinary excretion of free noradrenaline significantly increased after the ligation. Three weeks after the ligation, restraint and water immersion experiments were conducted. Under water immersion, gastric blood flow significantly reduced in rats with obstructive jaundice compared to controls. Acid output decreased in both groups. Gastric bleeding was noted in the fundic gland area significantly earlier in the ligated rats than in the non-ligated rats. Administration of noradrenaline s.c. 30 minutes before immersion significantly blocked the reduction in gastric blood flow and protected the gastric mucosa against acute bleeding under immersion. These results suggested that prolonged obstructive jaundice may deplete noradrenaline in the gastric mucosa, and that gastric mucosal ischemia caused by this sympathetic dysfunction plays an important role in the formation of acute gastric bleeding under obstructive jaundice.

Animals↗

Production of contiguously arranged chlamydospores in Candida albicans.

Contiguous arrangements of two to three chlamydospores occurred in a clinical isolate of Candida albicans. Time-lapse photography showed that the terminal cell of a cell chain was first transformed into a chlamydospore and such transformation proceeded centripetally to the next cell in the chain. Ultrathin sections revealed that the outermost layer of the three-layered chlamydospore wall was continuous throughout the interconnected spores, with the other layers surrounding each spore separately. Chlamydospore chains were common in this organism.

Candida albicans↗