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Biomedical subjects

H Mizutani

Publications and source records attributed to H Mizutani.

At least 73 records · Page 4Linked to original sources
PubMed1998

Increased cutaneous immunoreactive stem cell factor expression and serum stem cell factor level in systemic scleroderma.

Skin hyperpigmentation and itching are characteristic findings in systemic sclerosis (SSC) patients. Stem cell factor (SCF, c-kit ligand) is a multifunctional cytokine which can promote melanocyte and mast cell development. We investigated the SCF expression histopathologically in normal and SSC skin, and compared the expression with the serum SCF levels measured with a specific enzyme-linked immunosorbent assay. The epidermal and dermal immunoreactive SCF expression was markedly higher in the forearm skin of edematous phase SSC patients than in that of normal subjects. Tissue SCF expression declined from the sclerotic phase to the atrophic phase, where it was close to the normal level. In contrast, the elevated serum SCF level seen in the edematous phase samples was further increased in the sclerotic phase samples. The serum SCF level decreased in the atrophic phase, but it still remained at a level higher than that of the normal controls. Itching and increase of dermal mast cell number are characteristic of edematous phase SSC, and are in bears a parallel to the presently observed dermal SCF expression profile. Pigmentation is significant in sclerotic phase SSC and lasts to the atrophic phase, which may correspond to the serum SCF level observed here. These results indicate a contribution of the fibroblast membrane integral SCF in dermal mast cell development, and of the soluble serum SCF to melanocyte activation in SSC.

Adult↗
PubMed1998

Influence of food consistency and dental extractions on the rat mandibular condyle: a morphological, histological and immunohistochemical study.

The purpose of this study was to investigate the relationship between food consistency and the growth of the mandibular condyle in rats. Secondly, the effect of dental extractions on cartilage of the mandibular condyle was examined in young adult rats fed foods of varying consistency. Thirty-six male Wistar rats were divided into four groups: (A) Solid diet--non-Extraction (non-Ext.) group; (B) Solid diet--Extraction (Ext.) group; (C) Powder diet--non-Ext. group; and (D) Powder diet--Ext. group. Extractions were performed at 12 weeks of age. The mandibular condyles were removed at 1, 4, and 8 weeks after the extractions. The shape of the mandibular condyles in the powder diet groups (C and D) was significantly narrower. In the Ext. groups (B and D), the thickness of the hypertrophic zone was reduced one week after the extractions. In the powder diet groups (C and D), the intensity of the staining of fibronectin decreased in the proliferative zone regardless of the extractions. In group B, a decreased intensity of this reaction was observed one week after the extractions. From these results, it appeared that food consistency and/or dental extractions affected the morphology of the mandibular condyle and the histological characteristics of the mandibular condylar cartilage.

Age Factors↗
PubMed1998

Allopurinol hypersensitivity syndrome: hypersensitivity to oxypurinol but not allopurinol.

Allopurinol is a xanthine oxidase inhibitor widely used to control plasma uric acid levels. Episodes of hypersensitivity to the drug are not rare. A severe form of this with a generalized exanthem, fever and liver involvement has been termed the allopurinol hypersensitivity syndrome (AHS). Patch testing and lymphocyte stimulation testing (LST) are not helpful in confirming this sensitivity. Allopurinol works as a substrate of xanthine oxidase, and is rapidly oxidized into oxypurinol in vivo. Therefore, the biological half-life of oxypurinol is markedly longer than that of allopurinol. In addition, conspicuous pre-existing renal impairment has been noted in many AHS patients. Thus, it is possible that AHS is a manifestation of hypersensitivity to oxy-, not allopurinol. Here, we now report three cases of AHS in which there were significant lymphoproliferative reactions to oxypurinol but not allopurinol.

Adult↗
PubMed1998

Toxic epidermal necrolysis with severe gastrointestinal mucosal cell death: a patient who excreted long tubes of dead intestinal epithelium.

TEN is a severe inflammatory disease which is characterized by generalized epithelial destruction. The epidermis is the most common target of TEN, however, any epithelium can be involved. We report a toxic epidermal necrolysis (TEN) patient who excreted long tubes of dead intestinal epithelium. Epidermal keratinocytes and intestinal epithelium were found to undergo extensive apoptosis by TUNEL method. Drugs were speculated as the causative agents for this case, the causative drug has not been identified. In contrast to marked improvement of cutaneous manifestation and hepatic function by methyl prednisolone pulse therapy, the gastrointestinal symptoms did not respond to therapies, and the patient died by heart failure. Present case suggested a pathogenetic mechanism targeting antigens commonly expressed on the gastrointestinal epithelium and epidermis.

Fatal Outcome↗
PubMed1998

Analysis of water in Autonomous Biological Systems (ABS) samples.

Several soluble components, peptidase and amino acids, and carbon isotopic ratio in the water retrieved from flight experiments of Autonomous Biological Systems (ABS) as well as ground control samples are analyzed to interpret the condition, dynamics, material balance of the ABS ecosystems. Organic carbons in flight samples were found to be more abundant compared with the control ones, which suggested the uniform ecosystems in low gravity might easily dissolve more soluble components. The Mir-1997 flight sample showed higher C/N ratio probably because of the dissolution of carbon-rich plant materials.

Alkaline Phosphatase↗
PubMed1998

Microorganisms and plant of Autonomous Biological Systems (ABS) samples.

Distribution of microorganisms and cellular structure of an Autonomous Biological Systems (ABS) were studied with a special attention to the effect of space environments. Viable cell densities measured by the direct fluorescence microscopic method were in the order of 10(5) cells/ml for fractions 1 (upper suspension) and 2 (lower suspension), and 10(6) cells/ml for fraction 3 (sediments). These values were 10 to 100 times larger than the values obtained by the classical colony forming unit method. No difference between flight and ground samples was observed in the vertical distribution of viable microorganisms when fractionation and analysis were carried out after recovery. Intracellular distribution of chloroplasts in higher green plants, Ceratophyllum demersum, of flight samples was disturbed after 10 days of flight (24hrs/day light on). After 4 months of flight (Mir/STS-79/81) with 24 hrs light on, Ceratophyllum demersum was completely disintegrated. On the other hand, in the second 4-months-flight experiment with 16 hrs/day light on, Ceratophyllum demersum was only slightly deteriorated.

Aquaculture↗
PubMed1998

Performance of a digital video camcorder for the Autonomous Biological System experiment onboard Space Station Mir.

A video imaging and recording system was utilized in the Autonomous Biological System experiment onboard the space station Mir. Video image of the mini-ecological system was successfully recorded. The whole system was retrieved to the ground after its operation in orbit for four months. Performance of the video system is summarized here together with technical problems encountered. Defects of pixel had been developed in the imaging device. Cause of these defects could be attributed to its exposure against space radiation. Auto white balance was another function of the camcorder that was deviated from normal range of its performance once in orbit but recovered to normal after a while. Possible use of imaging devices for dosimetry is proposed to record space radiation environment at the site close to the experiment.

Animals↗
PubMed1998

Concluding remarks of Autonomous Biological Systems (ABS) experiments.

Team efforts for analysis on the Autonomous Biological Systems (ABS) space experiments are summarized here to conclude scientific findings, and to scope the extended studies in future. From the three experiments on Space Shuttle and Space Station Mir, a closed ecological system modeled by the ABS was verified to be capable of sustaining its members of animals and plants under space environment for a period of several months. The animals successfully completed their life cycle in space during the course of these experiments, this was the first time that the life cycle of higher organisms had been completed in space and ecological system. Importance of gravity for ecology was proven at the same time. Gravity is a dominant factor for ecology by formulating spatial patterns and distribution of members of ecological system. Under microgravity, the fate of ecological system was found highly sensitive against the variation of environmental factor, such as light illumination cycle.

Amino Acids↗
PubMed1998

Expression of endothelin-1 and effects of an endothelin receptor antagonist, TAK-044, at reperfusion after cold preservation in a canine lung transplantation model.

BACKGROUND: Rapid increase of pulmonary vascular resistance (PVR) early after reperfusion remains a major issue in clinical lung transplantation. A potent vasoconstrictor peptide, endothelin- plays an important role in various pulmonary pathophysiologic conditions and might induce increased PVR. We investigated the expression and influence of endothelin-1, and the effects of an ETA and ETB nonselective endothelin receptor antagonist, TAK-044, at reperfusion after cold preservation in a canine lung transplantation model. METHODS: Left single lung allotransplantation procedures were performed in three groups of animals. In group I (n=5) lungs were preserved for 12 hours; in group II (n=5) lungs were preserved for 18 hours; and in group III (n=6) lungs were also preserved for 18 hours, and TAK-044 (5 mg/kg) was administered just before reperfusion. All donor lungs were flushed and preserved with low-potassium dextran glucose solution at 4 degrees C. RESULTS: Six hours after reperfusion, arterial oxygen tension (mm Hg, inspired oxygen fraction=1.0) was 512.9+/-34.7 in group I, 152.4+/-46.7 in group II, and 509.6+/-29.0 in group III; PVR index (dyne x sec x cm(-5) x m2) was 1130+/-142 in group I, 1820+/-142 in group II, and 1287+/-191 in group III. Plasma endothelin-1 level was elevated significantly, and endothelin-1-like immunoreactivity was found in a variety of pulmonary vascular tissue and was seen less with immunohistochemical evaluation in group II in bronchial tissue. CONCLUSIONS: These results suggest that endothelin-1 is expressed as a result of ischemia-reperfusion injury and may worsen early graft function. TAK-044 is beneficial in protecting the graft from high pulmonary vascular resistance and pulmonary edema during the early posttransplantation stage.

Animals↗