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Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 937 records · Page 52Linked to original sources

Premature opening of the pulmonary valve in endomyocardial fibrosis.

Two-dimensional and Doppler echocardiographic findings in a 67-year-old man with endomyocardial fibrosis (EMF) are described. The two-dimensional echocardiogram showed typical features of EMF, right ventricular endomyocardial calcification, a thickened right ventricular wall, obliteration of the apex of the right ventricle and marked dilatation of the right atrium. In addition, premature opening of the pulmonary valve was observed during late diastole. The Doppler echocardiogram revealed forward flow from the right ventricle to the pulmonary artery, indicating the conduit state of the right ventricle. These findings were supported by cardiac catheterization and autopsy. Thus, two-dimensional and Doppler echocardiography are useful not only in making the diagnosis, but also in understanding the hemodynamic condition in EMF.

Aged↗

FR65814, a novel immunosuppressant isolated from a Penicillium strain. Taxonomy, fermentation, isolation, physico-chemical and biological characteristics and structure assignment.

FR65814, a novel immunosuppressant, was isolated from the cultured broth of Penicillium jensenii F-2883. The structure was assigned to be 5,6-dihydroxy-4-(1,2-epoxy-1,5-dimethyl-4-hexenyl)-1-oxaspiro++ +[2,5]octane by spectroscopic analyses. The compound suppressed the immune response at low concentration. In addition, a structually related component fumagillol, a known carcinolytic agent, was also isolated and found to show immunosuppressive activity.

Animals↗

Multiple cytokine activities and loss of interleukin 2 inhibitor in synovial fluids of patients with rheumatoid arthritis.

Attempts to detect immune mediators in rheumatoid arthritis synovial fluids (RA-SF) by bioassays have yielded conflicting results, and so we analyzed the immune reactions occurring within rheumatoid joints using monospecific immunoassays for cytokines such as interleukin 1 beta (IL-1 beta), interleukin 2 (IL-2) and gamma interferon (gamma-IFN). Furthermore, we examined the IL-2 inhibitors to clarify the immunoregulatory mechanism in the lesion. SF from active RA contained a significant amount of IL-1 beta and IL-2 but not gamma-IFN. In contrast IL-2 inhibitor activity was depressed in RA-SF regardless of clinical disease activity. Our results suggest that cytokine overproduction and deficiency of inhibitory signals may result in the overactivity of cytokines and the overactivity may participate in the joint lesions of RA.

Antibodies, Monoclonal↗

[Prognostic significance of the nuclear DNA content of a small adenocarcinoma of the lung].

DNA ploidy has been determined by flow cytometry in 28 surgical specimens from patients with adenocarcinoma of the lung (tumor diameter, 3.0 cm or less), and the relationship between DNA ploidy and the clinical stage and survival also has been investigated. The cases were classified according to the DNA index (DI) into group A (DI 1.00 to 1.50), group B (DI 1.51 to 2.00) and group C (DI greater than 2.01). A close relationship was observed between the DI and the survival rates but not between the DI and the clinical stage. Tumor ploidy is considered to be one of the prognostic factors and may be useful in selecting adjuvant therapy.

Adenocarcinoma↗

Disposition and metabolism of [14C]-amezinium metilsulfate in rats.

Disposition and metabolism of [14C]-amezinium metilsulfate (4-amino-6-methoxy-1-phenylpyridazinium methylsulfate, Risumic) were systematically studied in rats after intravenous (5 mg/kg) or oral (20, 100 mg/kg) administration. After oral administration at 20 mg/kg, blood level reached the maximum (Cmax) of 0.65 microgram eq/ml at 3 h (tmax) and decreased with t1/2 of 8.1 h. Levels in plasma and most tissues elevated to the Cmax at 3 h. The liver level was the highest (61 times as high as plasma level) of all examined tissues. Most tissue levels decreased thereafter essentially in parallel with plasma levels. The findings by whole-body autoradiography essentially agreed with those by radiometry. In lactating rats, milk levels were virtually similar to plasma levels. [14C]-Amezinium metilsulfate radioactivity in fetus and fetal blood was around 0.3 microgram eq/g, being about 1/10 level of maternal plasma level. About 24, 72 and 42% were excreted in urine, feces and bile, respectively. Re-absorption of biliary metabolites accounted for about 31%, being about 13% of orally given [14C]-amezinium metilsulfate. Plasma and aorta contained unchanged amezinium and glucuronide of hydroxyl amezinium MIII. In the brain, the major metabolite was O-demethyl amezinium MV and unchanged drug was not detected. Urinary metabolites were largely MIII glucuronide and the unchanged drug. Biliary metabolite was found composed mostly from MIII glucuronide. In feces, MIII and the unchanged amezinium were found. MIII and its glucuronide were novel metabolites which were identified by thin-layer chromatography and mass spectrometry.

Animals↗

[Electroencephalographic changes during experimental plateau waves].

The present study was designed to induce plateau waves by electrical stimulation of the brain stem and examine the changes in EEG during the plateau waves. Experiments were carried out on 10 adult mongrel dogs which were slightly anesthetized, immobilized and artificially respired. Electroencephalogram (EEG), intracranial pressure (ICP), systemic blood pressure (SBP) and cerebral perfusion pressure were simultaneously recorded on the electromagnetic tape after transorbital puncture of the intracavernous internal carotid artery. EEGs were recorded from cortical electrodes, and were analyzed by a frequency analysis. At the stage of increased ICP, the mesencephalic reticular formation was stimulated. Stimulation parameters, i.e., intensity, duration and frequency, were 0.1 mA, 1 msec and 40 - 50 Hz, respectively. The total duration of each period was 5 seconds. Spontaneous plateau waves occurred in 2 dogs associated with subarachnoid hemorrhage, subdural hematoma and intraventricular hemorrhage. Plateau waves were induced by electrical stimulation in the mesencephalic reticular formation in one of two dogs with spontaneous plateau waves. Twenty-one repetitions of electrical stimulation induced ten plateau waves. Two plateau waves were induced during slow EEG associated with desynchronization of EEG. Eight plateau waves were induced during fast EEG activity with no changes in EEG before and after the stimulation. In addition, plateau waves occurred immediately after short duration (5 seconds) of electrical stimulation. It seems that CBV increases during plateau waves are due to rapidly occurring neurogenic vasodilatation of cerebral vessels, later augmented by increases in cerebral metabolism. In conclusion, plateau waves are produced in a rigid condition within the cranial cavity by stimulation of the brainstem reticular formation which influences cortical activation and cerebral vasodilatation.

Animals↗

[Re-evaluation of determinants of the cardiothoracic ratio using two-dimensional echocardiography].

To evaluate the correlation of cardiothoracic ratios (CTR) on chest radiography with the sizes of the four cardiac chambers, we studied 41 normal persons and 77 cardiac patients using two-dimensional echocardiography (2DE). The transverse cardiac diameter and the CTR were ascertained from their chest radiographs. Using 2DE, each cardiac chamber was evaluated three-dimensionally, by measuring the short and long diameters of each left (LV) and right ventricle (RV), the diameter of the RV outflow, the anteroposterior, transverse, and long diameters of each left (LA) and right atrium (RA). These values were corrected using the square root of the body surface area. The correlation coefficient for the CTR was greatest in the long diameter of the LA (r = 0.84), and was greater in the atrial diameters (r greater than or equal to 0.71) than in the other diameters except for the transverse diameter of the RA (r less than or equal to 0.51). The contribution of each cardiac chamber to the transverse cardiac diameter was evaluated in 34 patients with cardiac enlargement by a method using the null hypothesis, which we originally designed. Consequently, the contribution of the LV to the CTR was definitely proven in two patients, that of RV in two, that of LA in 15 and that of RA in nine. These results indicated that the CTR is strongly influenced by enlargement of the LA.

Echocardiography↗

[The suction signal detected by color Doppler echocardiography in patients with mitral regurgitation: its clinical significance].

The present study clarified the clinical significance of the suction signal--regurgitant signal near the mitral valve in the left ventricle--as obtained by two-dimensional color Doppler echocardiography in patients with mitral regurgitation. The study population consisted of 39 patients with various heart diseases having mitral regurgitation. The presence of a mitral regurgitant signal was determined not only in the left atrium but in the left ventricle using the long-axis view, four-chamber view, and short-axis view. 1. The suction signal was observed in 17 cases; on the posteromedial commissure side in four; the central portion in seven; the anterolateral commissure side in five and the mitral aneurysm portion in one. The site of the suction signal indicated the mitral regurgitant orifice and was useful for identifying the regurgitant orifice particularly in cases with prolapse of the commissural scallop. 2. Left ventriculography was performed in 18 cases and the severity of mitral regurgitation was grade III/IV or IV/IV in seven of eight cases with suction signals and was grade II/IV in the remaining one, while it was grade II/IV or I/IV in all ten cases without the signal. Sensitivity was then 100% and specificity was 91% in diagnosing III/IV or greater regurgitation according to the presence of the suction signal. The left atrial jet distance, width and area in the 17 cases with suction signals were significantly greater than those of 22 cases without the signal (3.3 +/- 1.0 vs 1.9 +/- 0.7 cm, 1.4 +/- 0.7 vs 0.8 +/- 0.4 cm, and 4.2 +/- 2.8 vs 1.3 +/- 1.3 cm2, respectively). Thus, the suction signal in the left ventricle in mitral regurgitation provided useful information concerning not only the identification of a regurgitant orifice, but the grade of mitral regurgitation, as well.

Adult↗