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Biomedical subjects

A Mizuno

Publications and source records attributed to A Mizuno.

At least 307 records · Page 17Linked to original sources
PubMed1984

[Problems in estimating the severity of aortic regurgitation by pulsed Doppler echocardiography: with special reference to its distribution pattern].

We categorized the findings of aortic regurgitation (AR) by aortography (AOG) into the following four types, and compared them with the corresponding findings obtained by pulsed Doppler echocardiography (PDE) in 30 patients, and assessed the ability of PDE to observe the distribution of an aortic regurgitant flow. Type 1: A wide regurgitant jet distributed within the entire left ventricle (5 cases). Type 2: A narrow regurgitant jet passing through the center of the left ventricular outflow tract (9 cases). Type 3: A regurgitant jet with the shift of its direction to the either side (10 cases). Type 4: A regurgitant jet which is localized below the aortic valve (6 cases). AOG findings in 40% of Type 1 cases, 78% of Type 2, 80% of Type 3 and 67% of Type 4 were well consistent with those of PDE (an average of 70%). Therefore, we could predict the distribution of AR by PDE, although a correlation between both methods was not complete. The reasons of the inconsistence of these two methods were discussed. PDE is an possible method for evaluating the severity of AR.

Aortic Valve Insufficiency↗
PubMed1984

[Prostatic tissue and fluid levels of DL-8280].

The concentration of DL-8280, a new pyridone carboxylic acid, in the prostatic tissue and fluid after oral administration to man was studied. The drug was concentrated in the prostate and the concentration was dose-dependent. The ratios of prostatic tissue and fluid levels to serum levels were 1.62-1.79 and 1.65-1.96. respectively.

Administration, Oral↗
PubMed1983

Raman spectroscopic study of age-related structural changes in the lens proteins of an intact mouse lens.

Age-related structural changes in the lens proteins of a normal mouse lens have been monitored in situ by laser Raman spectroscopy. The Raman spectrum of an ICR-strain mouse lens nucleus showed virtually no change in the 550-850- and 900-1800-cm-1 regions as the mouse aged. Lens aging, however, did cause a significant intensity decrease of the Raman band at 880 cm-1 due to tryptophan residues, and the intensity decrease seems to be stepwise. This observation implies that a microenvironmental change of tryptophan residues takes place twice at different places of the lens proteins during normal aging. Particularly striking is that the intensity decrease of the band at 880 cm-1 proceeds in parallel with that of the Raman band at 2579 cm-1 due to a SH stretching mode for the first 4 months. Thus, the first microenvironmental change of tryptophan residues seems to be correlated with the formation of S-S bonds. In contrast to tryptophan residues, no evidence was observed of a microenvironmental change in tyrosine residues. In this respect, the structural changes of lens proteins in aging are sharply distinct from those in lens opacification, in which tyrosine as well as tryptophan residues undergo microenvironmental changes [Itoh, K., Ozaki, Y., Mizuno, A., & Iriyama, K. (1983) Biochemistry 22, 1773-1778]. The relative intensity of the band at 3390 cm-1 due to an OH stretching mode of lens water fell rapidly for the first 4 months and then decreased very gradually. The observation clearly exhibits the process of lens dehydration.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1983

Structural changes in the lens proteins of hereditary cataracts monitored by Raman spectroscopy.

Raman spectra have been measured for the lenses from cac-strain mice. These mice possess a hereditary defect and provide lenses at various stages of opacification. The Raman spectra of normal mouse lenses have been obtained also for comparison purposes. The amide I and III bands appear in very similar positions in the Raman spectra of cataractous and normal lenses, suggesting that the peptide backbone of main lens proteins does not undergo a major conformational change upon lens opacification. However, lens opacification causes significant changes in the intensity ratio of the tyrosine doublet near 840 cm-1 and in that of the Raman bands at 881 and 760 cm-1 due to tryptophan residues. These changes could be observed even in the incipient stage of hereditary cataract and became more pronounced with cataract development. These observations indicate that in the course of lens opacification some tyrosine residues undergo a change in their hydrogen-bonding environment and some buried tryptophan residues became exposed. In addition, the present Raman spectroscopic study provides insight into the 2SH leads to S-S conversion in lens proteins. It was found that the conversion proceeded at a faster rate in a hereditary cataractous lens than in a normal lens; however, this difference was fairly small at the early stage of cataract development. Importantly, the 2SH leads to S-S conversion was accelerated after nuclear cataract formation. These observations support the hypothesis that the formation of S-S linkages is not a predominant factor for initiating lens opacification. Probably the formation of S-S linkages plays an important role in stabilizing the protein aggregates which are the cause of lens opacification. The intensity of the SH stretching mode (2579 cm-1) was very weak or absent in the Raman spectrum of a well-developed cataractous lens, suggesting that most sulfhydryl groups form disulfide bonds. Moreover, the fact that this occurs without major conformational changes of peptide backbones implies that most cysteine residues in lens crystallins are accessible to solvent or are clustered closely together.

Aging↗
PubMed1983

Transseptal left-heart catheterization with Swan-Ganz flow-directed catheter.

Four cases of transseptal left-heart catheterization with the use of a Swan-Ganz flow-directed balloon-tipped catheter are reported. An 8.5F Teflon catheter covered with a Teflon tube (4 mm outer diameter) was inserted into the left atrium by the Brockenbrough technique. A Swan-Ganz catheter was then introduced into the left atrium through the Teflon tube and left-heart catheterization was performed. Unlike conventional methods, this method made it easier to insert a catheter into the left ventricle and also enabled advancement of the catheter into the aorta. Our experience suggests that this method is a valuable addition to cardiac catheterization laboratories.

Adolescent↗
PubMed1983

Surgery for chronic pericarditis--thirty-years' experience.

During the past 3 decades, surgical treatment was performed on 75 cases with chronic exsudative or constrictive pericarditis, except for cases suffered from malignant tumor or trauma. Among 7 cases with chronic exsudative pericarditis, 5 underwent pericardiectomy and 2 had a fenestration of the pericardium. As for constrictive pericarditis, pericardiectomy was performed on 68 cases. Excellent surgical results were obtained. The ages of the cases with constrictive pericarditis, who underwent surgery, were significantly higher in the last decade, and the occurrence of pericardial tuberculosis significantly decreased in the last 2 decades. Although pericardiectomy has been performed for constrictive pericarditis without exception, it also plays an important role in the treatment of chronic exsudative pericarditis, especially for cholesterin or tuberculous pericarditis.

Adolescent↗