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Biomedical subjects

M Komatsu

Publications and source records attributed to M Komatsu.

At least 235 records · Page 13Linked to original sources
PubMed1992

ATP-sensitive K+ channel-independent, insulinotropic action of glucose in the B-cells.

Although closure of the ATP-sensitive K+ (K+ ATP) channel produced by glucose metabolism in the B-cell has been considered mediating the major signal for glucose-induced insulin release, evidences indicating the existence of the K+ ATP channel-independent, insulinotropic action of glucose have recently been accumulated. Namely, glucose stimulates insulin release by the B-cell with a full inhibition of the K+ ATP channel closure by diazoxide, a K+ ATP channel opener, provided cytosolic calcium is elevated. Glucose clearly elicits insulin release even if the K+ ATP channel is maximally inhibited by high concentration of sulfonylurea. In this case, glucose-induced insulin release is associated with net increase, not decrease, of K+ outflow, indicating glucose is opening K+ channels. Thus, closure of the K+ ATP channel is highly unlikely to be the mechanism responsible for the insulinotropic action of glucose under these conditions. The K+ ATP channel-independent glucose action is dependent upon physiological glucose concentration (2-30 mM) and the degree of cytosolic calcium elevation. The K+ ATP channel-independent, glucose-induced insulin release shows gradually increasing monophasic pattern which temporally resembles the second phase response of glucose-induced insulin release. The role of glucose metabolism in the K+ ATP channel-independent glucose action remains to be established. Glucose action at the B-cell can now be subdivided into two classes: one is the K+ ATP channel-dependent and the other is the K+ ATP channel-independent. The two branches may be mutually interrelated to cause normal, biphasic insulin secretion.

Adenosine Triphosphate↗
PubMed1992

Marinesco-Sjögren syndrome with reduced cytochrome c oxidase in muscle.

The present study deals with the sisters of Marinesco-sjögren syndrome without parental consanguinity. Cranial MRI of sisters in a 0.5T superconducting magnet revealed the cerebellar hypoplasia or atrophy, especially in vermis and tonsils with dilatation of IVth ventricle. Microscopic findings of muscle biopsy indicated moderate variation of fibers with phagocytosis, rimmed vacuoles and no ragged red fibers with markedly decreased cytochrome C oxidase activity. 1H-NMR study of urine indicates the secondary decreased turnover rate in urea cycle due to high concentration of 3-hydroxy-n-butyrate.

Biopsy↗
PubMed1992

Thyroid function in premature infants.

The present study was performed using the simultaneous assays of free T4 and TSH levels in dried blood spots of filter paper for mass-screening of inborn errors of metabolism in order to clarify the thyroid function of premature infants. The subjects were divided in three groups: A group infants less than 1500 g at birth (n = 34, 27.4 +/- 2.6 weeks of gestational age), B group infants from 1500 to 2500 g at birth (n = 104, 35.6 +/- 2.4 weeks) and C group infants over 2500 g at birth (n = 490, 39.0 +/- 1.2 weeks). TSH levels were 4.51 +/- 3.03, 2.62 +/- 2.24 and 2.84 +/- 2.06 microU/ml in A, B and C group respectively and significant difference was recognized in group A and C. Free T4 levels were 0.71 +/- 0.42, 1.81 +/- 0.96 and 2.15 +/- 0.67 ng/dl, in group A, B and C respectively, and significant differences were recognized in all three groups. There was positive correlation between free T4 levels and gestational ages (Y = -2.413 +/- 0.11725X, r = 0.206, p less than 0.05).

Humans↗
PubMed1992

[A clinical study of the significance of the gradient between feeding arterial tissue polypeptide antigen (TPA) and draining venous TPA in assessing the risk for recurrent breast cancers].

The incidence of postoperative recurrence of primary breast cancers in 73 patients was correlated with the blood levels of tissue polypeptide antigen (TPA) in peripheral veins (V-TPA), feeding arteries (A-TPA), draining veins (V-TPA) and the gradient between the TAP levels in draining veins and feeding arteries (V-A TPA). With progression in the stage of the cancers, all parameters were increased. In stages II and III, the mean level of V-TPA was significantly higher than the mean level of A-TPA (p less than 0.05). In each stage, each parameter was increased in the patients with recurrences when compared with the levels in the patients with no recurrences. In patients with V-A TPA gradients greater than 30 U/L, the rate of recurrence was significantly higher when compared with patients with gradients less than 30 U/L (p less than 0.05). The clinical significance of this finding is that patients with V-A TPA gradient greater than 30 U/L should be closely followed because of the increased risk of recurrences.

Breast↗
PubMed1992

[An autopsied case of papillary thyroid carcinoma showing DNA heterogeneity-comparison of DNA content between primary focus and metastatic focus].

A 56-year-old female case of papillary thyroid carcinoma is reported. Nuclear DNA analysis using flow cytometry and immuno-histological staining with thyroglobulin, CA19-9 and CA125 of the primary and metastatic foci from the autopsy specimens were performed. Correlation between ploidy patterns and immuno-histological staining was not found. Although two histogram patterns namely DNA diploid (DP) and aneuploid (AP) with DNA index of 1.3 were seen in primary, sternal and lung metastatic foci, only DP pattern was seen in the lymph node metastatic foci.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

Genetic deficiency of complement component C8 in the rabbit: evidence of a translational defect in expression of the alpha-gamma subunit.

We examined the molecular basis for rabbit C8 alpha-gamma deficiency (C8D) using human C8 cDNA probes. Sequential probing of normal rabbit poly(A)+RNA revealed messages of 2.1, 1.9, and 0.8 kb for alpha, beta, and gamma, respectively. Corresponding analysis of C8D rabbit poly(A)+RNA identified messages for alpha and gamma of the same size and amounts as normal rabbits. Thus, C8 alpha-gamma deficiency in the rabbit appears to be the result of a translational rather than a transcriptional defect.

Animals↗
PubMed1991

The problems encountered in the surgical management of primary hyperparathyroidism.

The problems encountered in the diagnosis and treatment of primary hyperparathyroidism were studied in 69 cases. The accuracy of imaging for hyperplasia was less than that for adenoma or carcinoma and the major causes for multiple operations were a failure to locate the four glands and mediastinal adenoma. The intravenous administration of high doses of calcitonin could reduce the serum calcium level of patients in hypercalcemic crisis. Carcinoma required ipsilateral modified radical neck dissection because of lymph node metastases, and non-medullary thyroid carcinoma was often associated with primary hyperparathyroidism. We found removal of the parathyroid adenoma and biopsy or extirpation of only one macroscopically normal gland to be a fully satisfactory procedure after bilateral neck exploration and attempting to identify at least four glands.

Adenoma↗
PubMed1991

Gradual delay in glucose-induced first phase insulin secretion by the pancreatic islets of 7 week-, 6 month-, and 1 year-old rats.

The temporal profiles of insulin secretion by isolated pancreatic islets of male Wistar rats with various ages up to 1-year-old were studied using high glucose, potassium (K+) depolarization, and arginine as secretagogues. In the islets of 6-month-old rats, the onset and peak of glucose-induced first phase of insulin release were delayed for 1 min compared to those of 7--week-old rats. The onset and peak were further delayed for 1 min in the islets of 1-year-old rats. The onset of glucose-induced second phase of insulin secretion, and the onset and peak of K+ depolarization- and arginine-induced insulin release were not delayed in the islets of 6-month and 1-year-old rats. Glucose-stimulated increase in cytosolic free calcium ([Ca2+]i) seemed not delayed in the islets of 1-year-old rats. We conclude that the first phase of glucose-induced insulin release by the islets is selectively delayed as rat ages. It was suggested that the defect lies distal to the elevation of [Ca2+]i.

Aging↗
PubMed1991

Unusual clinical presentation of malignant histiocytosis in a 70-year-old woman.

A 70-year-old woman was admitted for evaluation of hepatosplenomegaly, fever and elevated serum LDH levels. A biopsy specimen of the liver revealed histiocytic proliferation at the portal triad, and a mild degree of hepatitis. A bone marrow biopsy specimen showed proliferation of histiocytes with minimal immaturity and atypism, and haemophagocytosis by the proliferated histiocytes. Fever, hepatosplenomegaly and elevation of LDH levels all disappeared spontaneously, and presumptive diagnosis of benign reticulosis with haemophagocytosis was made. One year later, fever, hepatosplenomegaly and elevation of LDH levels redeveloped, and the liver and bone marrow biopsy specimen showed proliferation of unequivocally malignant histiocytes. The patient died as a result of disseminated intravascular coagulation with shock 20 d later. We concluded that, in this case, malignant histiocytosis first presented as benign haemophagocytic reticulosis and, 1 year later, there was a typical malignant presentation.

Aged↗
PubMed1991

1H-NMR studies of urine in propionic acidemia and methylmalonic acidemia.

The present study deals with the usefulness of 1H-NMR spectroscopy in the chemical diagnosis of propionic acidemia and methylmalonic acidemia. A Varian VXR-500 spectrometer was used. 1H-NMR spectra of urine from a patient with propionic acidemia show peaks of 3-hydroxy-n-valerate, methylcitrate, propionyl glycine, 3-hydroxy-n-butyrate, lactate, 3-hydroxypropionate, tiglylglycine and hippurate. The assignment was made possible by the use of 2D COSY. The spectra from a patient with methylmalonic acidemia show methylmalonate and glycine. 1H-NMR spectroscopy has the advantages of requiring a short time for analysis, relatively small amounts of urine and no preliminary extraction.

Amino Acid Metabolism, Inborn Errors↗
PubMed1991

Two cases of acute pseudogout attack following parathyroidectomy.

Two cases of acute attack of pseudogout associated with primary hyperparathyroidism are reported. Case 1 suffered from acute pain and swelling of the right ankle and dorsal of the right foot. Case 2 suffered from unknown fever and pain of the bilateral jaw, shoulder, elbow, wrist and knee joints. Postoperative radiological studies revealed the association of chondrocalcinosis in both cases. Synovial fluid in case 2 was aspirated and analyzed for calcium pyrophosphate dihydrate crystal by microscopic examination.

Acute Disease↗
PubMed1990

The budding of defective human immunodeficiency virus type 1 (HIV-1) particles from cell clones persistently infected with HIV-1.

Three cell clones producing large numbers of infectious or noninfectious particles of human immunodeficiency virus type 1 (HIV-1), designated M 10/LAV-2, M 16/LAV-3, and MT/LAV-17, were isolated from persistently HIV-1-infected MT-4 cells. In M 10/LAV-2, the HIV-1 proteins were defective in the cleavage of gag precursor protein, and the particles were doughnut-shaped with a double-ring structure. These particles were produced by budding at the cell surface from crescentic structures followed by the formation of double-ring structures. The viral proteins in M 16/LAV-3 were defective in the cleavage of env precursor protein. The morphology of the virus particles was intact, and an electron dense bar-shaped core was seen inside a single-ring enveloped structure. The intact particles were released from the cell surface by a budding process in which crescent shape structures first appeared at the cell membrane, then subsequently just before release matured to a complete structure with an electron dense core. In MT/LAV-17, the synthesis of HIV-1 proteins was normal, and the particles were teardrop-shaped with an intact core structure. These particles were produced by budding with an electron dense core at the cell surface. Thus, it was suggested that the morphological maturation of HIV-1 particles was completed just before release from the cell surface in several cell clones producing HIV-1 particles of different morphology.

Antibodies, Monoclonal↗
PubMed1990

Acral granulomatous dermatosis.

A 17-year-old boy developed an acral granulomatous dermatosis which resembled clinically acrodermatitis continua of Hallopeau. The histology showed dermal and subcutaneous abscess formation with granulomas. The lesions responded to systemic corticosteroid therapy, with residual atrophy and contractures of the fingers.

Acrodermatitis↗