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Biomedical subjects

H Minami

Publications and source records attributed to H Minami.

At least 235 records · Page 13Linked to original sources
PubMed1983

Site of pulmonary hypoxic vasoconstriction studied with arterial and venous occlusion.

We applied the arterial and venous occlusion technique in an in situ, isolated left lower lobe preparation of a dog lung to compare the effects of hypoxia with the effects of airway pressure elevation, and the infusion of serotonin, norepinephrine, and histamine. The total arteriovenous pressure drop across the lobe was partitioned longitudinally into pressure drops across the relatively indistensible arteries (delta Pa) and veins (delta Pv) and across the middle distensible vessels (delta Pm). Hypoxia increased primarily delta Pm, as did elevation of airway pressure, whereas the vasoactive drugs increased either delta Pa or delta Pv. The increases in pulmonary arterial pressure (Pa) caused by hypoxia and by elevation of airway pressure were independent of blood flow rate, but increases in Pa induced by the vasoactive drugs were dependent on flow rate. We conclude that in the dog hypoxia acts primarily on small distensible vessels, whereas pulmonary vasoactive drugs constrict the relatively indistensible arteries and veins. It is possible that the increase in pulmonary vascular resistance during hypoxia did not involve smooth muscle contraction.

Animals↗
PubMed1983

Ventilation by high-frequency chest wall compression in dogs with normal lungs.

In 6 anesthetized and paralyzed supine dogs, ventilation by high-frequency chest wall compression (HFCWC) was accomplished by a piston pump rapidly oscillating the pressure in a modified double blood pressure cuff wrapped around the lower thorax. Testing applied frequencies at 3, 5, 8, and 11 Hz, applied peak cuff pressures ranged from 30 to 230 cmH2O. This produced swings of esophageal pressure as high as 18 cmH2O and peak oscillatory air flow ranging from 0.7 to 1.6 L/s. Oscillatory tidal volume declined with increasing frequency and ranged from a mean of 61 to 45 ml. After 30 min of applied HFCWC, arterial blood gas determinations revealed a mean PaCO2 of 29.3 mmHg at 5 Hz, 35 mmHg at 3 Hz, 36 mmHg at 8 Hz, and 51 mmHg at 11 Hz. Mean PaO2 improved from ventilator control values at 3 Hz, remained unchanged at 5 and 8 Hz, and declined at 11 Hz. In 2 dogs breathing spontaneously, HFCWC applied at 5 and 11 Hz resulted in a reduction in spontaneous minute ventilation, mainly by a reduction in spontaneous tidal volume, whereas arterial blood gas values changed slightly. One dog ceased to breath spontaneously within 5 min of application of HFCWC as the PaCO2 fell below control values. We conclude that in dogs with normal lungs, HFCWC may assist spontaneous ventilation. In paralyzed dogs, HFCWC may be of sufficient magnitude to cause hyperventilation.

Animals↗
PubMed1982

Circadian rhythm of brain susceptibility to haloperidol during chronic administration.

Circadian fluctuation has been reported to exist to the effects of haloperidol after acute administration. In an attempt to clarify the viability of chronotherapy with haloperidol, the antiapomorphine effect of haloperidol after chronic administration was investigated in the present paper. Haloperidol was administered once daily at the same time for 21 consecutive days to rats which were kept under 12 hr lighting conditions with light onset at 19:30. Then the chronology of the antiapomorphine effect was investigated. The antiapomorphine effect was significantly stronger in the group treated at 19:30 than that treated at 13:30. These data agreed with the results found after the acute administration of the drug. After chronic administration, no difference was found in the plasma and brain level of haloperidol due to the time of administration. These experimental results seem to suggest that a circadian rhythm in the brain susceptibility to haloperidol exists even during chronic administration.

Animals↗
PubMed1982

Solvent drag effect in drug intestinal absorption. I. Studies on drug and D2O absorption clearances.

It was shown that the intestinal absorption clearance of D2O (CLD2O) could be a more appropriate index to study the solvent drag effect than water volume flow which was the difference between water influx and outflux in the intestinal lumen. Then, the correlation between the intestinal absorption clearances of drugs (CLdrug) and CLD2O were studied using the in situ recirculating method in the rat small intestine. The drugs used were low molecular drugs, that is, benzoic acid, salicylic acid, p-hydroxybenzoic acid and antipyrine, and comparably high molecular drugs, that is, cephalexin (CEX), cefroxadine (CXD) and cephalothin (CET). CLdrug and CLD2O were obtained in hypertonic, isotonic and hypotonic perfused solution adjusted with sodium chloride. Consequently, the correlations for all drugs except CET were significant and high solvent drag effects were observed. CLdrug of benzoic acid, salicylic acid and antipyrine were approximately equal to CLD2O, suggesting that the intestinal mucosa could not distinguish these lower molecular drugs from water. For the high molecular drugs such as cephalosporins, however, some extent of reflection from the membrane was certainly found in CEX and CXD, and the extent in CET was assumed much larger than CEX and CXD, resulting that the contribution of solvent drag in CET could not be found. Consequently, it was suggested that the solvent drag had some important role in the intestinal absorption of cephalosporins.

Animals↗
PubMed1982

Chest pain: differentiating esophageal disease from angina pectoris.

Angina-like chest pain frequently arises from the esophagus. However, when a patient has chest pain, the gravity of possible myocardial ischemia indicates that a cardiac workup must be done. Those individuals with typical anginal pain who have normal multistage exercise tests or normal coronary arteriograms and any person with atypical chest pain should be thoroughly evaluated for esophageal disease. This evaluation should include a barium swallow, a Bernstein test, esophageal manometry, and, if indicated, esophagoscopy. Reproduction of the chest pain with the Bernstein test incriminates gastroesophageal reflux disease. Esophageal manometry is required to make the diagnoses of achalasis, DES, and hypertensive LES or esophageal body (Table 1).

Angina Pectoris↗