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Biomedical subjects

M Kono

Publications and source records attributed to M Kono.

At least 253 records · Page 14Linked to original sources

Heat-induced changes in the conformation of alpha- and beta-crystallins: unique thermal stability of alpha-crystallin.

Of the crystallin proteins of the lens, the principal subunit of the beta-crystallin, beta B2 (beta Bp), has been considered to be the only heat-stable protein because it does not precipitate upon heating. In our recent investigations, however, we have found that the alpha-crystallin from bovine lenses is not only heat stable but also does not denature at temperatures up to 100 degrees C. Using circular dichroism and fluorescence to monitor the conformational changes of alpha- and beta B2-crystallins upon heating, we found that alpha-crystallin maintains a high degree of structure, whereas the beta B2-crystallin shows a reversible sigmoidal order-disorder transition at about 58 degrees C.

Animals↗

Myocardial tissue pCO2 and calcium content during ventricular fibrillation and reperfusion periods.

Forty-one patients who underwent cardiac surgery under conditions of systemic hypothermia and intermittent cold crystalloid potassium cardioplegia were studied, in order to elucidate the effects of ventricular fibrillation and reperfusion on the myocardium, by using the intramyocardial pCO2 and temperature sensor. All patients were assigned to 2 groups, namely; group A (21 cases), in which the time between the aorta declamping and defibrillation was under 10 minutes, and group B (20 cases) in which the time was over 10 minutes. In both groups A and B, myocardial pCO2 increased at the rate of 3.58 +/- 1.70 and 2.16 +/- 0.62 mmHg/min (p less than 0.05) after aorta declamping, respectively and the myocardial pCO2 decreased at the rate of 5.59 +/- 0.60 and 4.18 +/- 0.76 mmHg/min (p less than 0.05) after defibrillation, respectively. In group A, the myocardial calcium content, pre-CPB (cardio pulmonary bypass) was 10.98 +/- 1.62 nmol/mg/dry weight and at the time of aorta declamping it was 15.90 +/- 1.81 nmol/mg/dry weight (p less than 0.05). In group B, the myocardial calcium content, pre-CPB, was 14.62 +/- 2.15 nmol/mg/dry weight and at the time of aorta declamping it was 18.23 +/- 4.36 nmol/mg/dry weight (p less than 0.05). At both three and six hours after the operation, the left ventricular work index per minute (LVWI) in group A showed better cardiac pump function than that in group B. We therefore conclude that when reperfusion is encountered, acidosis can be minimized by prompt defibrillation.

Body Temperature↗

A highly specific and sensitive radioimmunoassay of caerulein, an analogue of cholecystokinin-8.

A highly specific and sensitive competitive radioimmunoassay was developed for caerulein (CLN), an analogue of cholecystokinin-8 (CCK-8), in plasma and brain. Antiserum was produced in rabbit by immunization with N delta-[CLN-(1-6)]-ornithine amide conjugated with bovine serum albumin by the glutaraldehyde method. N alpha-[CLN-(1-6)]-lysine amide was labelled with 125I-Bolton & Hunter reagent and used as a labelled antigen after purification by high-performance liquid chromatography. This assay was highly specific for CLN, and cross reactivities for other related peptides, CCK-4, CCK-8, gastrin-I, and gastrin-(14-17), were not observed (less than 0.01%). The limits of determination in biological specimens after CLN administration were 11 pg/ml in human plasma and rat plasma and 80 pg/g in rat brain. This study showed that the slight structure difference between hapten and 125I-labelled antigen is important to the assay performance.

Animals↗

Detection of T-factor in lung cancer using magnetic resonance imaging and computed tomography.

The ability of magnetic resonance imaging (MRI) to detect T-factor was compared with that of computed tomography (CT) in 52 patients with primary lung cancer proven by surgery or autopsy, and the results were analyzed in relation to the operative and pathologic findings. In the diagnosis of tumor invasion of the heart and great vessels, MRI provided information as accurate as CT. The T1-weighted images in particular were of considerable value in separating the tumor from the mediastinal and hilar fat. Tumor extent in accompanying peripheral obstructive pneumonia or collapse was demarcated in 21% of the cases studied by CT and in 33% to 53% by MRI. On the other hand, the T2-weighted images obtained with longer echo time (TE) were useful in distinguishing the tumor from secondary changes.

Adenocarcinoma↗

[Conventional X-ray and CT diagnosis of lung cancer].

The recent improvement in techniques such as thin slice CT and Lung Nodule Simulator has increased the possibility to diagnose early lung cancer. However, it might be most important to observe subtle shadow on the conventional X-ray carefully for early detection of lung cancer.

Biopsy, Needle↗