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Biomedical subjects

M Ohe

Publications and source records attributed to M Ohe.

11 recordsLinked to original sources
PubMed1992

Maximum stress-volume index ratio of the left ventricle in hypertrophic cardiomyopathy.

To evaluate the left ventricular contractile state in patients with nonobstructive hypertrophic cardiomyopathy (HCM), we analyzed the maximum stress-volume index ratio (MSVR) using catheter-tip cineangiography in 11 patients with HCM and 16 normal subjects. The value of the MSVR in normal subjects was 6.48 +/- 1.25 kdyn/cm5/m2 (mean +/- SD) and we defined the range of the mean +/- 2 SD as the normal MSVR range. Six patients with HCM placed inside the normal MSVR range (IN), but the other 5 patients placed outside and to the right of the normal range (RIGHT). This suggests that the contractile states of the patients of the RIGHT group were depressed. Compared with IN, the end-diastolic and end-systolic volume indices of RIGHT were larger (EDVI; 69.3 +/- 6.9 vs. 96.1 +/- 11.1 ml/m2, p less than 0.01, ESVI; 18.2 +/- 3.2 vs. 29.1 +/- 8.3 ml/m2, p less than 0.05), but the ejection fraction did not differ (IN 73.5 +/- 5.7 vs. RIGHT 69.6 +/- 8.3%, NS). End-diastolic pressure of IN and RIGHT was higher than that of normal subjects (IN 16.5 +/- 4.5, RIGHT 16.7 +/- 4.6 vs. 8.3 +/- 2.5 mm Hg, both p less than 0.05), but there was no difference between the two groups in HCM. End-systolic pressure did not differ among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Hypoxic contraction of pre-stretched human pulmonary artery.

To clarify the mechanism of hypoxic pulmonary vasoconstriction in man, human pulmonary artery segments (2 mm O.D.) were suspended and changes in isometric force were measured. The arteries were contracted by hypoxia (PO2 43 +/- 2 Torr) developing a tension of 127 +/- 36 mg over the course of 15 min. This contraction was completely blocked by 10(-6) M L-isoproterenol, 10(-6) M nitroglycerin, partially blocked by 10(-8)-10(-6) M verapamil, unchanged by 10(-6) M phentolamine, 10(-6) M L-propranolol, 10(-6) M diphenhydramine, 10(-6) M guanethidine, 10(-7) M FPL 55712 and enhanced by 10(-6) M BAY K 8644, 10(-3) M procaine, 3 x 10(-6) M quinacrine, 10(-6) M indomethacin or 10(-6) M methylene blue. Removal of the endothelium significantly enhanced the magnitude of hypoxia-induced contraction. These results suggest that the human pulmonary artery constricts in response to hypoxia, at least in part, through activation of the voltage-dependent Ca2+ channels and that neither alpha, beta, H1 receptors, the lipoxygenase pathway nor neural reflexes are involved. They also show that the endothelium is not required for hypoxic contraction and that its presence reduces sensitivity to hypoxia.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

Lack of linkage between atopy and locus 11q13.

Atopy as defined in terms of IgE responsiveness was reported to be controlled by a single gene in British families, and this concept was further supported by a significant linkage between atopy and restriction fragment length polymorphism (RFLP) detected by a DNA probe specific to chromosome 11q13. To confirm this observation in a Japanese population, segregation and linkage analyses were done in four large families. Although segregation patterns of atopy were in agreement with the pattern of autosomal dominant inheritance, there was no significant linkage between atopy and locus 11q13. Alterations in the definitions of atopy did not affect the results. These findings suggested the presence of heterogeneity in genetic elements of atopy, even though atopy may be determined mainly by a single dominant gene.

Adolescent↗
PubMed1992

Modulatory role of EDRF in hypoxic contraction of isolated porcine pulmonary arteries.

To examine the hypothesis that suppression of basal release of endothelium-derived relaxing factor (EDRF) by hypoxia might be related to the mechanism of hypoxic pulmonary vasoconstriction, rings of porcine pulmonary artery (PA, 2 mm OD) were suspended in organ chambers and changes in isometric force were measured. Hypoxia significantly reduced endothelium-dependent relaxation induced by acetylcholine and augmented contractile response to phenylephrine. This augmentation by hypoxia was not seen in rings without endothelium. Contractile response to phenylephrine was also enhanced by removal of endothelium. With 15 min of hypoxia, PA contracted and guanosine 3',5'-cyclic monophosphate content decreased. Pretreatment with 10(-6) M methylene blue, 3 x 10(-7) M oxyhemoglobin, and 9.6 x 10(-5) M NG-monomethyl-L-arginine significantly enhanced hypoxic contraction. Furthermore, removal of endothelium also enhanced hypoxic contraction. These results suggest that suppression of basally released EDRF by hypoxia was not the cause of the contractile response to hypoxia and that EDRF modulates the hypoxic contraction of porcine PA in basal conditions at this diameter.

Acetylcholine↗
PubMed1992

P wave height during incremental exercise in patients with chronic airway obstruction.

We examined changes in P wave height in lead 2 of an ECG obtained during progressive exercise in 23 patients with COPD, and measured both P wave changes and pulmonary hemodynamics during exercise at a constant workload corresponding to approximately 50 to 60 percent of VO2 max in nine patients. The P wave response to exercise (delta P/delta VO2, %/ml/min), estimated by the relationship between percentage of change in P wave height and VO2, was significantly greater (p less than 0.01) in 15 patients who had a decrease in PaO2 with exercise (group A) than eight patients who did not have a fall in PaO2 with exercise (group B). There was a significant negative correlation between change in PaO2 and change in P wave height from rest to maximal exercise (r = -0.68, p less than 0.001). Oxygen therapy in nine patients in group A reduced the increase in P wave height during exercise. Furthermore, change in P wave height from rest to exercise correlated significantly with that of mean pulmonary artery pressure (r = 0.75, p less than 0.01). These results suggest that increase in P wave height during exercise in COPD patients is related partly to oxygen desaturation during exercise, and continuous measurement of P wave change may be useful for noninvasively predicting the pulmonary vascular pressure response to exercise.

Aged↗
PubMed1992

[A case of occult breast carcinoma with micronodular shadows on chest x-ray film].

A 57-year-old woman was admitted to our hospital for the evaluation of roentgenological micronodular shadows of the bilateral middle and lower lung fields. Physical findings were normal except for left axillary lymph adenopathy. The level of tumor marker NCC-ST-439 was markedly elevated (2800 U/ml). Histological examination of the transbronchial biopsy and the swollen lymph node biopsy specimens showed proliferation of identical tumor cells. Breast or lung carcinoma was suspected as the primary site. Echogram of the left breast showed microcalcification without a mass. The biopsy specimen obtained from the calcified lesion indicated occult breast carcinoma. From these findings the diffuse micronodular shadows on the chest roentgenogram were considered to be the metastatic lesions of occult breast carcinoma. This case indicates that occult breast carcinoma should be considered as a possible primary site for diffuse pulmonary metastatic lesions.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1977

Studies on the heterotropic interaction of hemoglobin. I. Mass spectrometric method for determination of the pKa of the beta-146 histidine residue in human hemoglobin.

A mass spectrometric method was developed to determine pH-dependent hydrogen-deuterium exchange at the C-2 position of the imidazole ring of histidine, after converting the amino acid to the methylthiohydantoin derivative. The amount of deuterium exchange in N-acetyl-histidine estimated by the present method was confirmed to be in good agreement with that determined by NMR spectrometry. N-Acetylhistidine was deuterated at various pH's. From the amount of deuterium exchange, a pseudo-first order rate constant (kpsi) was calculated. A pKa value of 7.2 for the amino acid was obtained from the relation between kpsi and pH. This method was applied to estimate the pKa value of beta-146 histidine in human hemoglobin. Human hemoglobin deuterated at various pH's was digested with carboxypeptidase A [EC 3.4.12.2] to release the beta-146 histidine. The amount of deuterium exchange in the isolated histidine was determined to obtain kpsi. From these measurements pKa values of 7.0 for the histidine in oxyhemoglobin and of 8.2 for that in deoxyhemoglobin were found at 36.5 degrees, respectively.

Deuterium↗
PubMed1977

Subunit structure of hemoglobins from erythrocytes of the blood clam, Anadara broughtonii.

Intracellular hemoglobins of the sea blood clam Anadara broughtonii consist of HbI dimer (33%) and HbII tetramer (60%). The molecular weights of globins of HbI and HbII were determined by sodium dodecyl sulfate (SDS)-gel electrophoresis to be 15,500 and 16,500, respectively. The existence of two dissimilar chains, alpha and beta, in globin from HbII tetramer was confirmed electrophoretically and the chains were separated by CM-cellulose chromatography in 8 M urea. In contrast, globin from HbI dimer showed a single band on two types of electrophoresis. The NH2-terminus and the COOH-terminus of HbI were determined to be proline and leucine, respectively. From the results of finger-printing, the alpha and beta chains from HbII were considered to have a rather similar profile, whereas globin from HbI was very different. The results obtained by amino acid analysis of each chain also supported the above findings. It was thus shown that HbII has an alpha2beta2 subunit structure, which is rare among invertebrate hemoglobins. On the other hand, HbI seems to have two identical subunits, designated as "gamma", and to exist as a "gamma2" dimer structure. Both Anadara Hb's appear to have no functional groups relating to the Bohr effect and to be unable to form a binding site for organic phosphates.

Amino Acids↗