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Biomedical subjects

N Hara

Publications and source records attributed to N Hara.

At least 433 records · Page 24Linked to original sources

Effect of methylmercury chloride on sleep-waking rhythms in rats.

Effects of methylmercury chloride (MMC) on circadian sleep-waking rhythms were examined in rats which had been chronically implanted with EEG and EMG electrodes. Bihourly distributions of wakefulness (W), slow wave sleep (SWS) and paradoxical sleep (PS) and 12-h amounts of W, SWS and PS during light and dark periods were measured before and after MMC administration for 2 successive days at 3 dose levels. A total dose of 10 mg MMC/kg body wt was found to be the threshold for inducing reversible changes in the sleep-waking patterns. A total dose of 30 mg MMC/kg produced an increase in both dark-phase SWS and PS as well as a decrease in light-phase PS at the expense of an increase in light-phase W and a delayed phase of the circadian PS rhythm. The delayed phase of the PS rhythm tended to persist after the increased SWS during the dark period returned to normal. Brain mercury concentrations were measured in order to find the dose-response relationship and the time dependence of the MMC-induced sleep disorder. The sleep-waking disorder was found to appear at lower levels of brain Hg and shorter latency than behavioral disorders of movement and postural maintenance previously reported [5-8].

Animals↗

[Effect of adjuvant immunotherapy with Nocardia rubra cell-wall skeleton in lung cancer].

A randomized clinical trial of intrapleural Nocardia rubra cell-wall skeleton (N-CWS) followed by intradermal N-CWS was performed against lung cancer patients from November, 1977 to June 1981. Totally, 190 patients were entered into this trial. The N-CWS treatment was effective in terms of prolongation of remission duration against not only operable but also inoperable patients. However, significant improvement of survival rate was observed only in operable patients, especially curative+relatively curative resection-group (p less than 0.05). The mode of recurrence was classified as local recurrence and distant metastasis in the curative+relatively curative resection-group. The rates of distant metastasis were 34.1 and 17.6%, respectively, in the control and the N-CWS groups. The rate of local recurrence was 13.6% in the control group, however, no local recurrence was observed in the C-NWS group. These results indicate the clinical effectiveness of the N-CWS treatment especially in curatively resectable lung cancer. No serious side effect was experienced during this trial.

Adenocarcinoma↗

Excitatory and inhibitory effects of acetylcholine on the anterior aorta muscle of Aplysia.

The acetylcholine (ACh) responses of anterior aorta muscle cells of Aplysia kurodai were studied by intracellular recording and ACh iontophoresis. Three different types of membrane potential change were observed in response to ACh pulses: a rapid Na+-mediated depolarizing response, a slow, mainly Cl-, in part K+-mediated, hyperpolarizing response, and Na+ (for depolarizing component) and Cl- (for hyperpolarizing component)-mediated biphasic response. The depolarizing response and the depolarizing component of the biphasic response were effectively blocked by hexamethonium or atropine. The hyperpolarizing response and the hyperpolarizing component of the biphasic response were completely blocked by tubocurarine. Low concentrations of ACh inhibited and relaxed the anterior aorta muscle; high concentrations of ACh excited the muscle and initiated contraction. The biphasic responses to ACh are likely due to the presence of more than one ACh receptor type on the same cell membrane of the anterior aorta muscle fiber.

Acetylcholine↗

Alteration of NADH-diaphorase and cytochrome b5 reductase activities of erythrocytes, platelets, and leucocytes in hereditary methaemoglobinaemia with and without mental retardation.

NADH-diaphorase and cytochrome b5 reductase activities of platelets and leucocytes, as well as erythrocytes, were found to be deficient in a patient with hereditary methaemoglobinaemia associated with moderate mental retardation and non-progressive neurological disturbance, in which hyperactive reflexes and involuntary movements were notable. In another methaemoglobinaemic patient with no mental or neurological abnormalities, these enzyme activities were defective in erythrocytes but normal in platelets and leucocytes. The first case was a generalised cytochrome b5 reductase deficiency with non-progressive encephalopathy. It is suggested that the detection of cytochrome b5 reductase activity in platelets, in addition to that in leucocytes, is useful for the assessment of a generalised enzyme defect. Genetical involvement of the present cases is discussed in association with the diaphorase gene loci in humans.

Adolescent↗

[The change of valence of chromium by acid treatment].

There are many kinds of chromium compounds in nature, and most of them exist as Cr6+- and Cr3+-compounds. Generally, these two kinds of compounds are stable in normal circumstances. When the chromium in biomaterial or in atmospheric substances is analyzed, the samples are usually ashed with strong acids at high temperatures to destroy the organic components, and chromium compounds are changed to water soluble salts in this ashing process. And then chromium is determined in various methods. The relation between the used acids and the behavior of chromium were investigated, and the following facts have been cleared. Though the total amount of chromium in the samples remains constant, the valence of chromium is apt to change easily in the ashing process (Cr6+ in equilibrium Cr3+). As Cr3+ is more stable than Cr6+ in acid solution, the reductive reaction proceeds mainly as (Cr6+ leads to Cr3+). But each acid has the peculiar reductive action on Cr6+. Even if the same acid is used, its reductive power changes very sensitively as the used conditions are altered. The reductive action of mixed acid differs from that of original acid remarkably. Certain acid has the oxidizing action on Cr3+. Thus, the mechanisms and reactions between strong acids and chromium are very complicated. So, for the determination of the amounts of individual Cr6+ and Cr3+, the oxidizing or reductive action of the used acid must be considered cautiously.

Cations↗

Effect of decreased plasma colloid osmotic pressure on development of pulmonary edema in dogs.

The effect of decreased plasma colloid osmotic pressure on the development of pulmonary edema was studied in anesthetized dogs. Lung lymph flow was used aa a sensitive and reliable indicator of fluid filtration rate in the lung. When plasma colloid osmotic pressure alone was reduced by slow infusion of saline, and hydrostatic pressure in the pulmonary vascular bed was maintained at normal level by exsanguination, lung lymph flow increased almost linearly with the reduction in colloid osmotic pressure, but was not increased more than five fold of the control, despite a reduction of 80% in the plasma colloid osmotic pressure. Furthermore, there was no evidence of fluid in the tracheal aspiration and no gross evidence of pulmonary edema. In contrast, both decrease in colloid osmotic pressure and increase in pulmonary capillary hydrostatic pressure produced a marked increase in lung lymph flow. This flow varied linearly with the level of the pulmonary artery wedge-plasma colloid osmotic pressure difference and approached twelve fold of the control, when the plasma colloid osmotic pressure was reduced by 73% and the pulmonary artery wedge pressure was elevated by 20 mmHg from the baseline. Our data indicate that decreased colloid osmotic pressure is not associated with the development of pulmonary edema, when there is no increase in pulmonary vascular hydrostatic pressure.

Animals↗

Relationship between postoperative hypoxemia and the operative site.

The effect of the site of operation on postoperative hypoxemia was studied in 104 patients undergoing thoraco-abdominal, thoracic, upper abdominal, lower abdominal, extra-abdominal and non-thoracic operations. The degree of postoperative hypoxemia was the most extensive in patients undergoing thoraco-abdominal, moderate in thoracic and upper abdominal operations, and minimal in lower abdominal and other operations. On the other hand, the duration of hypoxemia also differed with the surgical procedures. Arterial oxygen tension returned to almost control values by the 3rd postoperative day in cases of lower abdominal and extremity operations and by the 7th postoperative day in those undergoing thoracic and upper abdominal surgery. Postoperative hypoxemia, however, remained throughout the fourteen day study period, in patients undergoing thoraco-abdominal operation. True shunt was measured in 27 patients with thoraco-abdominal, thoracic and upper abdominal operations. An increase in true shunt was evident postoperatively in the entire group of patients. The increase was significantly larger and longer lasting in cases of thoraco-abdominal incision than that in cases of thoracic and upper abdominal incision alone. Differences in postoperative true shunt between cases of thoracic and upper abdominal incisions were nil.

Abdomen↗