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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 1,531 records · Page 85Linked to original sources
PubMed1984

The cardiac rhythm in accidental hypothermia.

An analysis of the ECGs from 60 patients with accidental hypothermia reveals several facts concerning rhythmicity. Echocardiograms were useful to determine the precise rhythm in cases without discernible P waves. Atrial fibrillation (AF) was unusual in mild hypothermia (greater than 32.0 degrees C). AF was often observed in moderate (32.0-26.0 degrees C) and moderately deep (less than 26.0 degrees C) hypothermia. However, about half of the cases with moderately deep hypothermia remained in sinus, atrial, or junctional rhythm. AF was usually converted to sinus rhythm without any antiarrhythmic agents soon after normothermia was restored. There was no significant difference in the mortality rate between the AF and non-AF groups. Therefore, no aggressive treatment for this arrhythmia seems to be necessary.

Atrial Fibrillation↗
PubMed1984

Human adult T-cell leukaemia virus is distinct from a similar isolate of Japanese monkeys.

We have compared the structural polypeptides of an adult T-cell leukaemia (ATL) virus (ATLV) isolate from a Japanese patient with ATL with those of a similar virus derived from a Japanese macaque monkey. Both are distinct but related entities. Their core polypeptides p19 could not be distinguished, but p24, another core polypeptide, and their envelope glycopolypeptides differ. The human virus directs the synthesis of a single intracellular glycopolypeptide, gp68, while the macaque virus specifies two such glycopolypeptides, gp57 and gp50. Furthermore, the glycopolypeptides of both viruses are serologically distinct. Thus, these viruses represent subtypes of the ATLV family and the macaque virus is apparently not involved in human ATL.

Animals↗
PubMed1984

Histochemical AMD electron microscopic studies of intercellular matrices of papilloma induced by painting DMBA on the skin of mice.

The localization and distribution of glycosaminoglycans (GAG) in papilloma tissue which was introduced by painting DMBA on the back skin of ICR mice were observed by light and electron microscopy. GAG consisting mainly of hyaluronic acid could be detected histochemically on the cell surface and extracellular matrices of the basal layer of the papilloma, but it could not be observed in the non-neoplastic epidermis. After incubation of tissue segments in a medium containing 35SO4, an autoradiograph was made, and 35S-radioactivity was observed in the interface between the papilloma epidermis and dermis. Ultrastructurally, the cell surface of keratinocytes in the basal layer of the papilloma was stained intensely with ruthenium red. A cell line was obtained from the papilloma, and GAG could be demonstrated on the cell surface and in the intercellular matrix of the cultivated keratinocytes by treatment with hyaluronidase. The significance of GAG in the proliferating squamous cells was discussed.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1984

The use of improved ruthenium red staining for the ultrastructural detection of proteoglycan aggregates in normal skin and lichen myxoedematosus.

Improved ruthenium red staining has been applied to normal human skin and lichen myxoedematosus skin lesions for the detection of the fine structure proteoglycan aggregates. In 4 samples of normal skin and in a patient with lichen myxoedematosus, the typical fine ultrastructures of proteoglycan aggregates, i.e., many short irregularly-curled filaments of varying lengths attached to long and rather straight filaments of hyaluronic acid were shown. Although lichen myxoedematosus is thought to be due to the faulty formation of proteoglycan aggregates, we suggest a different view, that this improved method of ruthenium red staining is useful for the detection of proteoglycan aggregates, and provides a better preparation for electron microscopy.

Humans↗
PubMed1984

Factors influencing the healing rate of gastric ulcer in hospitalised subjects.

A multiple linear regression analysis was carried out on 75 inpatients with gastric ulcer. In order to elucidate the effects of various factors - endoscopic and roentgenological findings, age, sex, medical history, and drugs such as antacids, anticholinergics or both - on the healing rate, these factors were compared between those with ulcer which healed within eight weeks after treatment and those which did not. In patients over 50 years of age, alcohol consumption of over 60 g per day until admission, duration of present ulcer pain for over three months, single ulcer, ulcer located in the lesser curvature and uneven elevation around the ulcer, there was significant delaying effect on ulcer healing. Drug ingestion, sex, smoking habits until admission, size, depth, and shape of ulcer, coexisting gastritis, and past and family history of ulcer disease had no significant effect on healing after eight weeks. The patients with less than two unfavourable factors (n = 46) had the best healing rate (100%) compared with those with three (n = 20) or four or more (n = 9) unfavourable factors. The healing rate of the latter two groups was 60% and 22%, respectively (p less than 0.001). A prognostic score based on these six factors represents the severity of gastric ulcer disease with regard to the healing rate in patients prescribed antacids, and/or anticholinergic drugs.

Adult↗
PubMed1984

Total adenine nucleotide stores and sarcoplasmic reticular Ca transport in ischemic rat heart.

We studied the relation between the contractility and metabolic changes in reperfusion after ischemia, and the effect of diltiazem on these changes, in an isolated rat heart perfused using the Langendorff method. After aerobic perfusion at 80 cmH2O, the perfusion pressure was reduced to 10 cmH2O to induce global ischemia. Substrate was removed from the perfusate during ischemia. After 30 or 60 min of ischemia, the heart was reperfused in an aerobic condition. During ischemia, the total adenine nucleotide level (TAN: sum of ATP, ADP, and AMP) was progressively reduced and the ATP-to-ADP ratio was one-third of the value obtained in an aerobic condition. With 30 min of subsequent reperfusion, ATP increased, and the shorter the duration of ischemia, the closer ATP/ADP approached the value of an aerobic condition, whereas TAN was equivalent to the value shown immediately before reperfusion. Thus the degree of ATP recovery by reperfusion mainly depends on the amount of TAN immediately before reperfusion and the mitochondrial function of oxidative phosphorylation that determines ATP/ADP. The calcium transport activity of the sarcoplasmic reticulum of myocardial cells was affected by ischemia and showed no amelioration or further deterioration by subsequent reperfusion. When diltiazem (10(-5)M) was added to the perfusate continuously from 5 min before ischemia, during ischemia, and until 10 min of reperfusion, the amount of TAN in ischemia and reperfusion and the calcium transport activity during reperfusion were maintained at relatively high levels. The degree of contractility recovery by reperfusion showed direct correlations with both the tissue ATP amount and the level of calcium transport activity in the sarcoplasmic reticulum.

Adenine Nucleotides↗
PubMed1984

Studies on chondrocytes from mandibular condylar cartilage, nasal septal cartilage, and spheno-occipital synchondrosis in culture. I. Morphology, growth, glycosaminoglycan synthesis, and responsiveness to bovine parathyroid hormone (1-34).

Methods for isolating chondrocytes from the craniofacial complex and culturing them in vitro were established. Chondrocytes which were isolated by collagenase digestion from mandibular condylar cartilage, nasal septal cartilage, and spheno-occipital synchondrosis grew well in vitro. All three types of chondrocytes actively synthesized glycosaminoglycans, a differentiated phenotype of chondrocytes, and responded well to parathyroid hormone. However, some different characteristics were noted among the three types of chondrocytes in culture.

Animals↗
PubMed1984

Immunoelectron microscopic (IEM) studies on glutaraldehyde-fixed renal specimen.

Immunofluorescent microscopy (IF) has become an essential tool in the routine diagnosis of renal pathology. It is thought that glomerular IF patterns represent different forms of immunologically mediated glomerular lesions. However, in order to preserve antigenicity IF is usually done on frozen, unfixed specimen by light microscopy and it is difficult to locate target macromolecules in tissue with precision. In order to establish the precise location of such macromolecules in glomeruli in relation to the ultrastructure, we undertook an immunoelectron microscopic (IEM) study on renal biopsies. Percutaneously biopsied tiny specimen was fixed in glutaraldehyde and processed with protease. Using peroxidase-labeled antisera, a direct IEM was done. With this technique, target macromolecules corresponded well not only to electron-dense deposits but also to IF patterns. In one case of membranous nephropathy, immunoglobulin (Ig) was found to be outside of the glomerular basement membrane (GBM), while IgA was seen to be inside the GBM. For this same case, a similar localization of immunoglobulins was not revealed by IF. In conclusion, IEM is a useful technique that can broaden our knowledge of pathogenic mechanisms in glomerular disease.

Adult↗
PubMed1984

Effect of administration of triiodothyronine on aspartate aminotransferase in pyridoxine-deficient rats.

The state of thyroid function and the effect of triiodothyronine (T3) administration on aspartate aminotransferase isozymes in the livers of rats fed on a diet with or without pyridoxine were examined. Decreased thyroid function in pyridoxine-deficient rats was demonstrated using malic enzyme as a marker of thyroid function in the liver. Administration of T3 increased cytosolic aspartate aminotransferase in the liver of pyridoxine-deficient rats, but not of control rats.

Animals↗
PubMed1984

Fibrin gels as biological filters and interfaces.

We present data which show that fibrin gels are ordered network structures, the porosity of which is determined by the amount of thrombin being present during the activation step preceding gelation. On activation of fibrinogen, fibrinopeptides are released and simultaneously polymers are formed, obeying apparent first order kinetics. The pore size of the network is inversely related to the rate of polymer formation. It is proposed that at the time of gelation the polymers form an ordered lattice structure, which in the organism may serve as a biological interface.

Chromatography, Gel↗
PubMed1984

[Concentrations of cefotaxime in serum and myocardial tissue].

Serum and myocardial concentrations of cefotaxime (CTX) were measured in 20 adult patients undergoing cardiac surgery. To all of these patients 1.0 g of CTX was given intravenously (in the range of 13.7--29.0 mg/kg) at the beginning of operation. The serum concentrations of CTX were determined at 5, 10, 30, 60 minutes and 120 minutes after administration. Myocardial concentrations of CTX were also determined at about 30 minutes (group I), 60 minutes (group II) and 120 minutes (group III). The following results were obtained. Average serum CTX concentrations were 132.8 +/- 34.1 micrograms/ml at 5 minutes, 92.0 +/- 23.1 micrograms/ml at 10 minutes, 44.6 +/- 12.3 micrograms/ml at 30 minutes, 24.5 +/- 7.7 micrograms/ml at 60 minutes and 12.3 +/- 4.9 micrograms/ml at 120 minutes after administration. Average myocardial CTX concentrations were 10.0 +/- 3.7 micrograms/g in group I, 3.6 +/- 2.1 micrograms/g in group II and 2.3 +/- 1.8 micrograms/g in group III. The myocardial/serum concentration ratio was 0.22 +/- 0.14 in group I, 0.15 +/- 0.08 in group II and 0.18 +/- 0.12 in group III, respectively. These results suggested that the serum and myocardial concentrations of CTX were high enough to be prophylactic and therapeutic against not only aerobic but also anaerobic and opportunistic infections during and after cardiac surgery.

Adult↗