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Biomedical subjects

J Matsuda

Publications and source records attributed to J Matsuda.

At least 199 records · Page 11Linked to original sources

Characteristics of mutant mice (ICGN) with spontaneous renal lesions: a new model for human nephrotic syndrome.

Spontaneous nephrotic mice (ICGN mice), a new mutant strain of mouse from outbred ICR, were clinically, macroscopically, histologically and immunohistochemically studied to establish their value as a model for human nephrotic syndrome. Most of the affected mice developed proteinuria, hypoproteinaemia and hypercholesterolaemia, and some of them developed systemic oedema. A high concentration of blood urea nitrogen (BUN) and a low haematocrit value were also observed. The kidneys of severe cases showed a decrease in size and had a yellowish granular surface. These findings indicated that the mice were terminally affected by chronic renal insufficiency. Histopathology demonstrated glomerular lesions consisting of thickened basement membranes of the capillary loops with irregular spike-like protrusions and enlargement of the mesangium unaccompanied by cellular proliferation. The immunofluorescence technique revealed positive granular staining for IgA, IgG and IgM and to a lesser extent for C3 along the capillary loops in affected mice. The similarity between this spontaneous disease and human nephrotic syndrome caused by idiopathic glomerular lesions is discussed. ICGN mice may be a useful animal model for this human disease.

Animals↗

Frequent infection with human T-cell lymphotropic virus type I in patients with AIDS but not in carriers of human immunodeficiency virus type 1.

Antibody to human T-cell lymphotropic virus type I (HTLV-I) was measured in 49 Japanese patients (48 with hemophilia) infected with human immunodeficiency virus type 1 (HIV-1) and in 18 hemophiliacs who were not infected with HIV-1, by use of an enzyme-linked immunosorbent assay (ELISA). The antigen used was a gag-env hybrid protein constructed in vitro and expressed in Escherichia coli. This assay detected a specific antibody against HTLV-I. Four of the 18 HIV-1-negative hemophiliacs (22%) were positive for anti-HTLV-I antibody; their geometric mean titer was 951 U/ml. Seven of the 12 patients (58%) with acquired immune deficiency syndrome (AIDS) were positive for anti-HTLV-I antibody, and 8 of 35 HIV-1 + AIDS-free carriers (23%) were positive. The difference between the prevalence of HTLV-I infection in the two groups was statistically significant (p less than 0.0297). The geometric mean titer of antibody in the patients with AIDS was 318 U/ml and that for the HIV-1 + AIDS-free carriers was 1,496 U/ml. These findings suggest that HTLV-I infection could be one of the factors in the development of AIDS in individuals infected with HIV-I.

AIDS-Related Complex↗

[The possibilities of hyperthermia from an engineering standpoint].

The possibilities of hyperthermia are discussed from the engineering technology standpoint. Microwave equipment yields powerful effects against a superficial tumor. RF capacitive method and annular phased array system (APAS) are typical heating methods against a deep-seated tumor. We have proposed that in the RF capacitive method the diameter of the applicator electrode should be more than 1.5 times the distance between two electrodes. In APAS another exciting method (TE mode) has been proposed. Electric current flows through the short axis of the body by the TE mode excitation. We are developing re-entrant resonant cavity applicators which have the characteristics to heat cylindrical regions of small diameter. We can install an x-ray tube inside the re-entrant electrode. This method is suitable for deep and concentrated heating. We conclude that the recent rapid development of various kinds of hyperthermia apparatus makes it possible to heat more safely and effectively the deep-seated regions of the human body.

Biomedical Engineering↗

[Essential thrombocythemia with Philadelphia chromosome].

Essential thrombocythemia is a myeloproliferative disorder not known to have consistent cytogenetic abnormalities. A 38-year-old woman with essential thrombocythemia having Philadelphia chromosome (Ph1) is reported. The patient first presented with gastrointestinal bleeding, accompanied by thrombocytosis. Treatment of the gastrointestinal bleeding did not influence the elevation of platelet counts. The patient's clinical and hematological manifestations were consistent with essential thrombocythemia, but not with any other myeloproliferative diseases. Ph1 chromosome was constantly proved in bone marrow preparations from this patient over two years and four months and gave us a certain impression that Ph1 chromosome might have had some relation to development of essential thrombocythemia to chronic myelogenous leukemia in this patient.

Adult↗

Development of nephrotic ICGN mice--the origin, reproductive ability, and incidence of glomerulonephritis.

ICGN is a strain of spontaneous nephrotic mice with nonproliferative glomerular lesions. It was derived from an outbred Yok: ICR colony in our laboratory. The renal disease constantly occurred in animals of the first to the tenth generations (greater than 13.0%; 70 days of age). When affected males were mated with unaffected females, the incidence of the disease in their offspring was 38.8% (n = 49) at 70 days after birth. When both parents were affected, their offspring were all affected (n = 12). The disease evenly progressed in both sexes. It usually began 40 to 150 days after birth and death occurred within two months after onset. The animals usually showed sufficient reproductive ability as long as unaffected females were used for mating.

Animals↗

Heterogeneous mechanical response of rat knee menisci to thermomechanical stress.

Thermodilatometric, dynamic thermomechanical, and light-microscopic analyses were done on the anterior and posterior regions of the rat knee menisci to correlate regional differences in morphology and extracellular matrix composition with regional mechanical behavior. Following the administration of a general anesthetic, menisci were excised from 12 young female Sprague-Dawley rats. During thermodilatometric and thermomechanical testing, tissue temperature was increased at a constant rate of 3.5 degrees C/min from 30 to 100 degrees C. Light microscopy revealed regional differences in cell density and proteoglycan content. The anterior horn was significantly heavier (greater than 87%) and thicker (greater than 60%) than the posterior region. During thermal analyses, both the anterior and posterior horns decreased in tissue thickness as the temperature increased from 30 to 73 degrees C. After 73 degrees C, however, the posterior horn expanded significantly, whereas the anterior remained in a comparatively contracted state. The rates of linear contraction and expansion of the posterior horn were seven times those of the anterior horn, and the stiffness of the anterior horn was significantly greater than the posterior horn.

Analysis of Variance↗

Adaptation of rat knee meniscus to prolonged exercise.

The morphological and biochemical adaptations of knee meniscus to prolonged exercise were studied. Female Sprague-Dawley rats maintained under controlled environmental conditions were randomly assigned to either an endurance-trained or a sedentary group. Training consisted of a progressive exercise protocol on a motor-driven treadmill, 5 days/wk for 12 wk. Knee lateral menisci were obtained from anesthetized rats and used for morphological and biochemical analyses. Gastrocnemius succinate dehydrogenase increased 65% in the endurance-trained group, as evidence for a training effect. In the trained group, collagen, proteoglycan, and calcium concentrations increased significantly in the posterior region of the lateral meniscus. In contrast, no significant changes were found in the anterior region of the lateral meniscus. The region-specific changes in meniscal concentrations of calcium and matrix macromolecules in response to prolonged exercise are consistent with the distinctly different mechanical properties and functional roles of the anterior and posterior regions of the rat knee meniscus.

Adaptation, Physiological↗

Regional biochemical and morphological characteristics of rat knee meniscus.

The biochemical and morphological characteristics of the anterior and posterior regions of the rat knee meniscus were studied. The anterior meniscal horn was thicker and contained a lower concentration of DNA, hydroxyproline, and uronic acid as compared to the posterior region. The calcium concentration in the anterior region, however, was significantly greater than the calcium concentration in the posterior horn. Presence of a significant concentration of calcium in the normal rat knee meniscus is unique to rats and uncommon in other mammalian species.

Animals↗

Detection of antibodies to HTLV-I and -III in sera from Japanese hemophiliacs.

Sera from 50 Japanese hemophiliacs were screened for antibodies to human T-lymphotropic retrovirus types I and III (HTLV-I and -III). As a whole, antibody to HTLV-I, antibody to HTLV-III, and antibodies to HTLV-I and -III were detected in sera from 2, 17, and 6 hemophiliacs, respectively. Among them, two hemophiliacs developed acquired immunodeficiency syndrome who were positive for both antibodies to HTLV-I and -III in sera. All of the others were asymptomatic. Most of the blood products transfused into these hemophiliacs were imported from abroad, whence the source of HTLV-III infection presumably originated. However, since quite a high percentage of these antibody-positive hemophiliacs was positive for antibody to HTLV-I, even though they are native residents in HTLV-I nonendemic areas of Japan, some special factors may have participated in HTLV-I infection. These special factors should be investigated in the future.

Acquired Immunodeficiency Syndrome↗

Clinical effect of intravenous immunoglobulin on chronic idiopathic thrombocytopenic purpura.

High dose immunoglobulin infusions showed a marked effect on platelet counts in eight out of nine chronic ITP patients and in one SLE patient. In the comparison of different IgG-preparations, the pepsin treated IgG F (ab')2 showed no platelet elevation while the sulfonated did. The elevated platelet count could not be maintained after discontinuation of IgG infusions, but in six out of ten patients the platelet level remained above the pretreatment values. This new treatment seems to be safe and effective in adulthood ITP.

Adolescent↗