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Biomedical subjects

K Mizoguchi

Publications and source records attributed to K Mizoguchi.

At least 91 records · Page 5Linked to original sources
PubMed1990

Fluorometric determination of carnitine in serum with immobilized carnitine dehydrogenase and diaphorase.

A fluorometric flow-injection method for determining carnitine with use of immobilized enzymes carnitine dehydrogenase (EC 1.1.1.108) and diaphorase (EC 1.8.1.4) was developed and applied to the assay of carnitine in serum of patients treated with valproic acid. After fractionation and hydrolysis of carnitines in serum samples by perchloric acid and potassium hydroxide, liberated carnitine was converted to resorufin by immobilized carnitine dehydrogenase and diaphorase in the presence of beta-NAD+ (1.0 mmol/L), resazurin (12.5 mumol/L), and Tris acetate (0.6 mol/L, pH 9.0) at 37 degrees C. The fluorescence intensity of resorufin was monitored at lambda Ex 560 nm and lambda Em 580 nm. The calibration curve was linear for carnitine amounts from 0.1 to 1.0 nmol. Quantitative analytical recovery and satisfactory within- and between-run imprecision of carnitine in each carnitine fraction were obtained. Interference by bilirubin, serum albumin, and hemoglobin was negligible. Carnitine deficiencies were detected in about 20% of the valproic acid-treated patients (n = 198). The present method should be useful for monitoring carnitine deficiencies in clinical laboratories.

Alcohol Oxidoreductases↗
PubMed1989

Mode of alloantibody-mediated blockade of allo-sensitization for tumor allograft rejection.

The mode of alloantibody-mediated inhibition of allo-sensitization for tumor allograft rejection was studied. Relatively small amounts of anti-H-2d alloantiserum administered shortly before or after injection of allogeneic spleen cells blocked the allo-sensitization for second-set tumor allograft rejection. In contrast, the alloantiserum injected shortly before inoculation of tumor barely enhanced the tumor growth. The passively administered alloantiserum inhibited the sensitization for allospecific cytotoxic T lymphocyte responses in vitro. Further study revealed that the allo-sensitization could be blocked with antiserum specific against only one of the expressed H-2 antigens on stimulator cells. Correspondingly, H-2Dd-monospecific monoclonal antibody (IgG2a) was effective in inhibiting the sensitization with cells expressing multiple H-2 alloantigens. These results suggest that antibody-mediated inactivation of stimulator cells as a whole is an important mechanism of the allograft enhancement.

Animals↗
PubMed1989

Lupus anticoagulant as a risk factor for cerebral infarction and habitual abortions.

A case involving a 34-year-old female with a progressive hemiparesis is described. She had a history of repeated spontaneous abortions. The CT and magnetic resonance imaging (MRI) showed a multiple cerebral infarction. A 99mTc perfusion lung scintigram demonstrated diffuse bilateral perfusion defects in the lungs. The presence of lupus anticoagulant (LA) was detected from the laboratory data and the thrombosis in the genital organ. The repeated abortions were probably due to thrombosis in the placental vessels caused by LA. High dose steroid therapy was effective in suppressing the LA activity and in preventing progression of the clinical symptoms.

Abortion, Habitual↗
PubMed1989

Sexual attitudes of the adolescent in Japan today.

Over the last ten years, Japan has witnessed a two-fold increase in the number of surgical abortions among the teenage population. The increase in teenage sexual activity indicated by this trend has been a source of much concern and study. The accelerated social change going on in Japan over the last century has produced a series of contrasting generations, each differing in social attitudes from its predecessor. In order to elucidate the current sexual attitudes of Japanese adolescents, we will present extracts from four surveys. Finally, we "tally the results" with regard to statistical findings together with their potential and likely implications.

Adolescent↗
PubMed1989

[The effect of the elastase on aminonucleoside nephrosis].

In this paper, we studied the effect of elastase on aminonucleoside (AN) nephrosis which is considered a model of focal glomerular sclerosis (FGS). Elastase is an enzyme which disintegrates elastin, discovered by Balo, and used in the treatment of arteriosclerosis and hyperlipidemia. It has also been known to improve metabolism of acid mucopolysaccharides, so, this study focused on metabolic improvement. Three groups of male Sprague-Dawley rats were studied and observed at regular intervals; 30, 60, 90 days. The ANE group (AN + elastase) was administered one shot of AN (10 mg/100 g B.W.) during the test interval, while elastase (5 mg/kg B.W.) was injected 5 days/week for the entire test interval. The AN group was administered one shot of AN only. The third group was a control (C). The following results were observed: (1) Focal segmental hyalinosis and sclerosis (FSHS); ANE group was weaker than AN group. (2) Other significant qualifying glomerular changes (vacuolar change and hyaline droplets of the epithelial cells, adhesion, and foam cells); ANE group was weaker than AN group. (3) Anion loss in GBM was shown by a lack of colloidal iron staining under light microscopy, and by a lack of PEI particles under electron microscopy; there was significantly less anion loss with ANE group, than with AN group. The findings suggest that elastase has an affect on the metabolism of acid mucopolysaccharide and collagen in sclerotic lesion, and may restrain the progress of amino-nucleoside nephrosis.

Animals↗
PubMed1989

[A case of adult Still's disease with severe pulmonary complications].

We reported a case of adult Still's disease accompanied by pericarditis, pleuritis and extensive pneumonitis with respiratory failure. A 59-year-old woman was admitted to our hospital because of high grade fever and sore throat. She had a spiking fever between 38 degrees C and 40 degrees C. Surface lymph nodes were palpable in the neck and inguinal lesions and hepatosplenomegaly was recognized. Laboratory data showed a marked increase in peripheral leukocytes, erythrocyte sedimentation rate, liver dysfunction and anemia. Serologic tests were negative for various autoantibodies and rheumatoid factor. She received various antibiotics, but there was no improvement. Later, a rheumatoid rash which suggested adult Still's disease developed. The diagnosis of adult Still's disease was made by skin biopsy and clinical course. Although pericarditis, pleuritis and extensive pneumonitis were accompanied with severe respiratory failure, her symptoms improved with steroid pulse-therapy. A transbronchial lung biopsy revealed moderate fibrosis and cell infiltration in alveoli.

Arthritis, Juvenile↗
PubMed1989

[Pathomorphological studies on arterial cushion. 1. Rat normal kidney].

The present studies are an attempt to elucidate the vulnerability of focal glomerular sclerosis (FGS). The distribution and morphology of the arterial cushions were studied in rat renal arteries by light microscopy, transmission electron microscopy and scanning electron microscopy (SEM) using of the renal vascular casts. The arterial cushions were observed at a region of the branching arteries from the arcuate arteries and the interlobular arteries. They were extensively demonstrated mainly in the mid cortex and juxtamedullary cortex by the serial sections, but not in the subcapsular cortex. The arterial cushions showed valve-like protrusions and consisted of three components, such as the endothelial cells, the smooth muscular cells and the interstitial ground substances, electron microscopically. The cushions are covered by the endothelial cells which often showed various variation in thickness. Also these had deep processes which elongate into the interior of the cushions. The cells of interior portions of the cushions were modified smooth muscular cells. These cells contained numerous myofibrils and a large number of scattered glycogen granules. No nerve fibers were seen within the cushions. The modified smooth muscular cells were embedded in a loose matrix (probably acid mucopolysaccharides) which contained strands of basement membrane like material. The cushions were observed on the wall of the arcuate and interlobular arteries in the cortex except for subcapsular cortex by SEM. They showed elongated indentation surrounding lumen of their arteries. These results of the observation, the cushion may be important factor for the regulation of blood flow in small arteries and arterioles. The disorder of autoregulation of interlobular arteries due to dysfunction of the cushions with anionic loss were assumed to be one of the important factor in progress to the glomerular sclerosis.

Animals↗
PubMed1989

[Muscle carnitine deficiency associated with myalgia and rhabdomyolysis following exercise].

A case of 16-year-old female with myalgia and myoglobinuria following prolonged exercise was reported. Neurological examination revealed mild weakness of proximal muscle in the lower extremities. Serum CK, LDH, myoglobin were significantly increased during the attacks. On biopsy, the muscle fibers contained myriad lipid-filled vacuoles, in predominantly type 1 fibers. Electron microscope examinations revealed numerous lipid droplets adjacent to mitochondria and glycogen particles. Carnitine level in the patient's muscle was markedly reduced (under 5% of control), but the serum carnitine concentration was normal. The muscle carnitine palmityl transferase level was not depressed. A forearm ischemic test resulted in normal lactate production. On exercise tolerance test by a bicycle ergometer, mild exercise (15-30 watts for 15 minutes) induced myalgia and marked elevation in serum CK, lactate and pyruvate, while severe exercise showed no increase in serum CK level. The findings suggest that the energy production system in the skeletal muscle was impaired. However, the enzyme activities of NADH oxidation in mitochondria and the anaerobic glycolysis pathway were within normal limits. During fasting (36 hours), there was a normal production of ketone bodies, suggesting that hepatic metabolism of lipids was normal. She showed good response to L-carnitine therapy.

Adolescent↗
PubMed1989

[A case of multiple sclerosis with high CSF antibody titer to HTLV-I].

A case of multiple sclerosis (MS) in a 39 year old Japanese female with high antibody titer to human T-lymphotropic virus type I (HTLV-I) in serum and cerebrospinal fluid (CSF) was reported. At the age of 15, gait and urinary disturbances accompanied by sensory impairment in the lower abdomen and lower extremities developed suddenly. The motor disturbance slowly progressed to tetraparesis over a period of 15 years with several remissions. At the age of 28 the patient suffered from an acute loss of visual acuity, unilateral initially, and became blind by the age of 34. On admission to our department in September, 1987, the patient was alert and had spastic paraparesis, the impairment of all sensory modalities below the level of Th 10 and urinary disturbance. Weakness of facial muscles, nystagmus, deviation of the tongue and dysarthria were also noted. By the PA method, the antibody titer to HTLV-I was measured x512 in the serum and x64 in the CSF. Western blotting analysis of the CSF disclosed the bands to p19, p24 and p28 of HTLV-I gag proteins. The CSF contained a few ATL-like atypical cells and showed mild lymphocytosis, but the total protein was not increased. The computed tomography revealed diffuse low density areas in the cerebral white matter. The magnetic resonance imaging disclosed high intensity signal areas in the cerebral white matter and in the dorsolateral portion of the medulla oblongata on the T2 weighted image. The link of HTLV-I infection to the pathogenesis of human demyelinating diseases was discussed.

Adult↗
PubMed1988

Further evidence for H-2-unrestricted induction of minor histocompatibility antigens-specific T cell immunity in vivo.

Antigenic requirements for inducing minor histocompatibility antigens (MIHA)-specific T cell immunity for second set rejection (SSR) of a MIHA-allogeneic tumor were studied. An intravenous injection of surprisingly small numbers (10(4)-10(5] of live allogenetic spleen cells (SC) effectively primed mice for SSR of the allogeneic tumor, and this immunity was developed as early as 2-3 days after injection of the SC. In contrast, sonication-disrupted allogeneic SC, which should be readily processed by host antigen presenting cells (APC), were not active as immunogens, even at a dose 1000 times higher than the minimum effective dose of live SC. The possibility that host APC preferentially receive MIHA antigens shed by live allogeneic SC for T cell activation was ruled out. These results demonstrated that antigen processing via conventional pathways is very little involved in the mechanism of T cell activation. Under such restricted experimental conditions, the induction phase but not the effector phase of the MIHA-specific T cell immunity was shown to be H-2-unrestricted.

Animals↗
PubMed1988

Biphasic radiation-sensitivity of the transplantation immunity for rejection of an allogeneic ascites tumor.

Transplantation immunity for second-set rejection of an allogeneic ascites tumor was induced by sensitizing mice with H-2-identical allogeneic spleen cells, and radiation-sensitivity of this immunity was studied. The immunity was not severely affected by 400 rads whole-body X-ray irradiation given at one day before the initial antigenic stimulation. In contrast, it was totally inactivated by 300-400 rads irradiation that was given one day before tumor challenge. An adoptive cell transfer experiment showed that alloreactive memory cells responsible for the immunity were unexpectedly highly radiosensitive. The immunity (memory), however, became resistant to 400 rads irradiation soon (one day) after challenge with the allogeneic tumor, and was resistant to 1500 rads for rejection of the tumor that was challenged at the second time when the initially challenged tumor was rejected. Corresponding to these observations, cells for allospecific CTL responses in peritoneal cavity of mice showed corresponding biphasic radiation-sensitivity.

Animals↗
PubMed1988

Augmentation by Corynebacterium liquefaciens of erythrocyte surface H-2 expression and alloimmunogenicity for antibody responses.

Intravenous injection of killed Corynebacterium liquefaciens induced a population of red blood cells that expressed both H-2K and H-2D antigens at exceptionally high density and displayed augmented immunogenicity for H-2 alloantigen-specific B cell activation. Injection of killed Escherichia coli or E. coli lipopolysaccharide was ineffective for the generation of such RBC. RBC that express H-2 antigens at high density first appeared at 7 days after injection of C. liquefaciens. These RBC persisted for more than 50 days, although they lost H-2 antigens gradually with time. The observed phenomenon was not due to enhanced erythropoiesis and peripheral release of immature RBC (reticulocytes); populations of both mature and immature RBC of mice injected with C. liquefaciens expressed H-2 antigens at high density, whereas those from normal mice or mice injected with phenyl hydrazine did not. Appearance of RBC expressing H-2 antigens at high density was preceded by a temporal increase in H-2 expression of bone marrow cells that included precursors of RBC. It was concluded that RBC expressing H-2 antigens at high density were descendants of bone marrow cells whose H-2 expression was augmented by C. liquefaciens. The present communication would be the 1st report of the bacteria-mediated augmentation of cell surface expression and activity of major-histocompatibility-complex class I antigens on host cells in vivo.

Animals↗
PubMed1988

Dynamics of cytotoxic T lymphocyte precursors in vivo assessed by change in the radiation sensitivity. Evidence for development of radiation-sensitive memory cells without clonal expansion.

The dynamics of cytotoxic T lymphocyte precursors (CTL-p) in mice injected with allogeneic spleen cells (SC) was studied with special reference to changes in their radiation sensitivity. Whole-body 400 rad X-ray irradiation of allo-SC-primed and unprimed mice virtually abolished the capacity of their SC to proliferate and to generate CTL in primary or secondary mixed leucocyte culture (MLC). However, the impaired ability of SC to generate CTL in the primary MLC was restored by interleukin 2 (IL-2). This showed that helper cells whose activity was replaceable with IL-2 (IL-2-producing cells) were functionally more radiation-sensitive than CTL-p in unprimed mice. In contrast, the radiation-impaired activity in secondary MLC was not restored by IL-2, suggesting that memory CTL-p in allo-SC-primed mice were unexpectedly sensitive to radiation. The D37 values determined from the percentage of residual CTL-p activity of SC in bulk cultures 1 day after irradiation were 525 rad for virgin CTL-p and 75 rad for memory CTL-p. Further studies demonstrated that the radiation-sensitive memory CTL-p were generated from relatively radiation-resistant precursors, largely independent of radiation-sensitive IL-2-producing cells and of cellular proliferation. The mean frequency of CTL-p in SC measured by limiting dilution assay was not significantly increased by the priming. This supports our conclusion that the development of the memory CTL-p activity in allo-SC-primed mice did not depend on clonal expansion. Whole-body 400 rad-irradiation reduced the frequency of CTL-p in SC from unprimed mice to 1/2-1/3 and that in SC from allo-SC-primed mice to 1/8-1/15. This supports the view that the majority of radiation-resistant virgin CTL-p functionally mature to radiation-sensitive memory CTL-p without cellular proliferation in allo-SC-primed mice.

Animals↗