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Biomedical subjects

I Hayashi

Publications and source records attributed to I Hayashi.

At least 253 records · Page 14Linked to original sources

Adipogenic and anti-adipogenic factors in the pituitary and other organs.

Adipose conversion of cultured 3T3 cells is known to depend on an adipogenic factor present in serum. In the presence of this factor, extracts of different organs were found to inhibit the adipose conversion. The most active extracts were derived from brain, uterus, and pituitary, but other organs also possessed appreciable activity. Fibroblast growth factor partially purified from both brain and pituitary was much more active in suppressing adipose conversion than were crude extracts of the corresponding organs. Purified platelet-derived growth factor was also an effective inhibitor. Of all the tissue extracts tested, only pituitary possessed, in addition to the inhibitory activity, an adipogenic factor similar to that demonstrated previously in serum. This was revealed at concentrations of extract too low for the inhibitory factor to be effective. Under these conditions the pituitary extract had a specific adipogenic activity orders of magnitude higher than that of serum. We suggest that the adipogenic factor of serum may originate in the pituitary.

Adipose Tissue↗

[Clinical studies of dibekacin intravenous challenge on respiratory tract infections (author's transl)].

Dibekacin was used for the treatment of 5 patients with bacterial respiratory tract infections (4 cases of Ps. aeruginosa and 1 case of S. marcescens) intravenously. Serum levels of DKB was observed by the method of enzyme immunoassay (EIA) and bioassay and no differentiation was observed between EIA and bioassay. Four cases of Ps. aeruginosa and 1 case of S. marcescens were all disappeared in 5 or 7 days of administration. No side effects were observed. The results obtained in this study indicate that DKB intravenous challenge might become one of the important method on respiratory tract infections.

Adolescent↗

K-582, a new peptide antibiotic. I.

A new basic peptide antibiotic designated as K-582 was isolated, purified and characterized. When K-582 was applied to a column of Al2O3 or Biol-Gel P-2 or CM Sephadex, two major peaks which were named Fraction I (K-582 A) and Fraction II (K-582 B) were obtained. The nitrogen content, the behavior in color reaction, the absorption bands of amide linkages in the infrared absorption spectrum, 1H NMR spectrum and C-13 NMR spectrum indicated the peptide nature of K-582 A and K-582 B. K-582 was effective against yeasts, but inactive against other Gram-positive bacteria, Gram-negative bacteria and Mycobacterium. The toxicity was low in mice.

Animals↗

A prosthetic myocardium for repair of localized defects of the left ventricle: concept and hemodynamic feasibility.

As an approach to the treatment of patients with large but circumscribed akinetic or dyskinetic regions in the left ventricular myocardium as sequelae of acute myocardial infarction, excision of the defect and implantation of a mechanical functional equivalent of myocardium is suggested. Experimental investigation of this technique is described. Hemodynamic data from a series of dog experiments indicate that activation of the prosthetic myocardium after excision of the left ventricle is followed by improvement in various hemodynamic parametres of interest. Although substantial experimental work must be completed and difficult bioengineering problems solved, preliminary results have encouraged us to continue our investigations of the prosthetic myocardium. An imposing array of treatment methods is now available to the clinician who must deal with the sequelae of acute myocardial infarction. Selecting from pharmacologic, electrophysiologic, and surgical approaches the physician can in many instances design a treatment plan precisely tailored to the clinical problem. Large left ventricular aneurysms and their functional equivalents of ventricular dyskinesis or hypokinesis continue, however, to represent a class of problems in which established techniques have been less than satisfactory. Surgical excision with closure of the defect is regarded as effective for small aneurysms, but such procedures may so compromise cardiac output in patients with large ones as to be unacceptable. Unfortunately, it is just the latter group in which medical palliation is least likely to be effective in managing congestibe failure, angina, and other pathophysiologic manifestations. A relatively unusual approach derived from in-series techniques of mechanical assistance to the failing circulation (1) offers the theoretical possibility of a treatment tailored to the problem of a large ventricular aneurysm. Experimental investigation of this technique in the Surgical Research Laboratory at the Sinai Hospital of Detroit has progressed to the point that a report of our experiences to date may be of interest.

Animals↗