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Biomedical subjects

H Miyajima

Publications and source records attributed to H Miyajima.

At least 109 records · Page 6Linked to original sources

Spontaneous nonthymic T cell lymphomas in young Wistar rats.

Spontaneous acute lymphomas and related leukemias, occurring in three of 2,974 male Wistar rats used as controls in toxicity studies during the last 14 years (1974-1987), were examined by light and electron microscopy and by using immunohistochemistry. At autopsy, conspicuous hepatosplenomegaly was noted. Morphologically, tumor cells of all three rats were medium-sized lymphocytes with many mitotic figures proliferating mainly in the spleen, liver, and bone marrow. Virus-like particles were not detected. Immunohistochemically, almost all tumor cells were positive for thy-1 antigen but negative for hematopoietic and differentiation markers such as W3/13, W3/25, OX4, OX8, and OX12. The results suggest that the lymphomas in these three rats were derived from T cells.

Animals↗

[Subacute myeloneuropathy after abuse of nitrous oxide: an electron microscopic study on the peripheral nerve].

We have experienced a case of myeloneuropathy following habitual abuse of nitrous oxide. We report clinical and pathological findings of this case with review of literatures. A 36-year-old dentist was first admitted to our hospital on August 17, 1983 because of numbness of both lower legs and unsteady gait. He had recreationally inhaled nitrous oxide 30 to 60 minutes everyday since a year ago. Neurological examination showed ataxic broad-based gait, moderate loss of pain and touch sensation in the lower limbs up to patella. Position and vibratory senses were more severely impaired. Deep tendon reflexes increased in the upper extremities and at the knees, but diminished at ankle jerks. Muscle strength was normal. Prominent Lhermitte's sign was present. Except for reduced serum vitamin B12 level, laboratory results were normal. Needle electromyography showed high amplitude and long duration NMU in the right quadriceps and anterior tibial muscles. Motor nerve conduction velocity was 34 m/sec at the right posterior tibial nerve and could not be detected at the left. Sural nerve biopsy was performed. The density of the myelinated fibre measured on transverse section was in normal range but degenerated fibres were occasionally recognized. Single teased nerve fibre showed various degree of myelin ovoid along the fibre. Myelin loss was shown to occur in some parts of the fibre. Electron microscopy showed myelin splitting and formation of intramyelinic vacuoles containing myelin debris. Axon was almost normal at least in the early stage of degeneration. Later, axon disappeared with destruction of myelin sheath. These nerve changes largely demonstrated demyelination but it was occasionally accompanied with axonal degeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[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↗

Anti asialo GM1 antibody detected in the patients' sera from systemic lupus erythematosus and Behçet's diseases with neurological manifestations.

A high incidence of antibody to asialo GM1 was observed in the sera from the patients with Systemic Lupus Erythematosus (SLE) and Behçet's disease with neurological manifestations, using Enzyme Linked Immunosorbent Assay (ELISA), and Thin-layer Chromatography (TLC) immunostaining. The sera from 60 out of 102 cases of SLE with neurological disorders and 6 out of 10 patients with neuro Behçet's disease showed antibody activity against asialo GM1 but not against the asialo GM2, GM1 and galactocerebroside. In 7 out of 123 cases SLE having a history without neurological manifestations and 1 out of 19 Behçet's patients without neurological disorders, antiasialo GM1 antibody could be detectable. However, sera from the patients with other autoimmune diseases, such as RA (60 cases) and P S S (32 cases) or from normal subjects did not show any antibody activity against asialo GM1. Antiasialo GM1 antibody activity presents in both IgM and IgG immunoglobulin classes by class specific ELISA and TLC immunostaining. These studies suggest that detection of antiasialo GM1 antibody may be useful in clinical diagnosis and these autoantibody plays a important role in the pathogenesis of neurological manifestations accompanying SLE and Neuro-Behçet's disease.

Antigen-Antibody Complex↗

Studies on murine IgE with monoclonal antibodies. I. Characterization of rat monoclonal anti-IgE antibodies and the use of these antibodies for determinations of serum IgE levels and for anaphylactic reactions.

Rat monoclonal antibodies were constructed by fusion of immunized rat spleen cells with a nonsecreting mouse myeloma cell. Two monoclonal antibodies (6HD5 and HMK-12) were selected for further study. Both reacted with various IgE molecules of different specificities and different allotypes, but did not react with immunoglobulins of other isotypes and with light chains. These antibodies were therefore anti-isotypic (IgE) and not anti-allotypic or anti-idiotypic. It was shown by competition studies that these antibodies recognize different epitopes on the FcR epsilon fragment. A sensitive ELISA for the quantitation of murine IgE was developed with these monoclonal antibodies; the sensitivity was between 2 and 250 ng/ml for detection of serum IgE levels. Good correlation was obtained with protein amounts as determined by enzyme-linked immunosorbent assay (ELISA) and passive cutaneous anaphylaxis (PCA) activities. Both monoclonal antibodies were used to study anaphylactic reactions elicited by IgE antibodies. Both could inhibit PCA reactions and both could elicit reverse PCA reactions.

Animals↗

Nucleotide sequence of the cDNA encoding the precursor for mitochondrial serine:pyruvate aminotransferase of rat liver.

The nucleotide sequence of the mRNA coding for the precursor of mitochondrial serine:pyruvate aminotransferase of rat liver was determined from those of cDNA clones. The mRNA comprises at least 1533 nucleotides, except the poly(A) tail, and encodes a polypeptide consisting of 414 amino acid residues with a molecular mass of 45,834 Da. Comparison of the N-terminal amino acid sequence of mitochondrial serine:pyruvate aminotransferase with the nucleotide sequence of the mRNA showed that the mature form of the mitochondrial enzyme consisted of 390 amino acid residues of 43,210 Da. The amino acid composition of mitochondrial serine:pyruvate aminotransferase deduced from the nucleotide sequence of the cDNA showed good agreement with the composition determined on acid hydrolysis of the purified protein. The extra 24 amino acid residues correspond to the N-terminal extension peptide (pre-sequence) that is indispensable for the specific import of the precursor protein into mitochondria. In the extension peptide there are four basic amino acids distributed among hydrophobic amino acids and, as revealed on helical wheel analysis, the putative alpha-helical structure of the peptide was amphiphilic in nature. The secondary structures of the mature serine:pyruvate aminotransferase and three other aminotransferases of rat liver were predicted from their amino acid sequences. Their secondary structures exhibited a common feature and so we propose the specific lysine residue which binds pyridoxal phosphate as the active site of serine:pyruvate aminotransferase.

Amino Acids↗

Regulation of murine IgE production in SJA/9 and nude mice. Potentiation of IgE production by recombinant interleukin 4.

Serum IgE levels were determined in different strains of mice with enzyme-linked immunosorbent assay by using rat monoclonal anti-murine IgE antibodies in normal and in Nippostrongylus brasiliensis-infected mice. After infection, serum IgE levels were high in BALB/c and CB-20, low in SJL/J and SJA/20 mice, and not detected at all in SJA/9 and nude mice. Surface IgE-positive cells were greatly increased in BALB/c and SJL/J mice after infection, but not in SJA/9 and nude mice. Most surface IgE-positive spleen cells were also surface IgM- and surface IgD-positive. When spleen cells from SJA/9 or nude mice were stimulated in vitro with lipopolysaccharide and recombinant interleukin 4 (formerly B cell-stimulating factor 1), IgE was produced and detected in the supernatants of these cultures. In addition, surface IgE-positive cells could be detected in these cultures. Most of the surface IgE-positive cells were surface IgM- and surface IgD-negative, unlike those seen in the spleens of Nippostrongylus-infected BALB/c and SJL/J mice. These observations show that SJA/9 and nude mice have IgE-producing precursor B cells, and after appropriate stimulation interleukin 4 can induce them to secrete IgE.

Animals↗

Detection of IgE antibody-forming cells by passive cutaneous anaphylaxis using cell extract from lymphoid organs.

IgE and IgG2a antibody-forming cells in the lymphoid organs of rats were detected by passive cutaneous anaphylaxis (PCA) reaction using the extract from the tissue. The amount of antigen-specific IgE and IgG2a antibodies in the tissue extract could be expressed as PCA titers in which extract from 10(8) cells/ml was used as starting dilution. The total amount of antigen-specific IgE antibody produced in mouse IgE-producing hybridoma cells was calculated by maximum dilution of the extract to the minimal amount of IgE antibody inducing PCA reaction, i.e., 4 ng/ml. In the case of the extract from mouse IgE antibody-forming hybridomas, the minimal number of hybridoma cells to be detected by this method proved to be 2-3 X 10(4) cells/ml.

Animals↗

The Leu-1 B-cell subpopulation in patients with rheumatoid arthritis.

Ly-1-B cells have been shown to be elevated in autoimmune mice, especially NZB, and to secrete IgM autoantibody, suggesting that Ly-1 B cells may participate in autoimmune diseases. In this study, B-cell populations carrying Leu-1, a human T-cell surface molecule homologous to mouse Ly-1 (Leu-1 B), were examined by dual fluorescence flow cytometry, in peripheral blood lymphocytes taken from patients suffering from various autoimmune disease. These B cells were shown to be present at a significantly high percentage in rheumatoid arthritis (RA) patients. There was no significant correlation among the incidence of Leu-1 B cells, rheumatoid factor (RF) titers, and the amount of IgM production in vitro. There was, however, a significantly high incidence of Leu-1 B cells in RA patients with a high RF titer (greater than 5 X 2(13), suggesting that these B cells in RA may play an important role in IgM RF production in vivo.

Antigens, Differentiation, B-Lymphocyte↗

Familial apoceruloplasmin deficiency associated with blepharospasm and retinal degeneration.

A 52-year-old woman had a newly recognized disorder of familial hypoceruloplasminemia, blepharospasm, retinal degeneration, and high-density areas in CT of the basal ganglia and liver scan. Immunofixation electrophoresis disclosed apoceruloplasmin deficiency. Kinetic, x-ray analysis, and histochemical study showed accumulation of iron in liver and brain, but not of copper. Intestinal copper absorption was reduced, but liver uptake was increased. Ceruloplasmin is involved in iron metabolism, and the findings suggest that hypoceruloplasminemia due to lack of apoceruloplasmin was causally linked to the iron deposition in basal ganglia and other organs, leading to blepharospasm and retinal degeneration.

Apoproteins↗

Water intoxication due to excessive water intake: observation of initiation stage.

A patient who had experienced water intoxication despite normal renal function and normal urinary diluting ability was observed during the initiation stage of hyponatremia. Upon the excessive water intake (10 to 15 L) for several days, he developed moderate hyponatremia (121 mEq/L) and headache, an early symptom frequently seen in water intoxication. During this period, his urine was maximally dilute (50 to 60 mOsm/kg H2O), and his urinary sodium excretion increased. This report suggests that 10 to 15 L of water intake for several days can cause water intoxication in subjects with normal urinary diluting ability and that the increase in sodium excretion is prerequisite for the high urine flow rate.

Adult↗

[An electrophysiological method for detecting diabetic retinopathy in rats].

The present study was undertaken to devise an electrophysiological method for detecting diabetic retinopathy in rats. The electroretinogram (ERG) and visual evoked potential (VEP) were recorded from unanesthetized and unrestrained rats rendered diabetic with a single i.v. injection of streptozotocin (STZ) at 35 or 40 mg/kg. The STZ-treated rats showed signs of diabetes: hyperglycemia, glucosuria, hypoinsulinemia, polyuria and increased water intake. Amplitudes of the ERG a- and b-waves and oscillatory potentials (OPs) on the b-wave were decreased and latencies of these waves were prolonged gradually after STZ was administered. Especially, latencies of the OPs became significantly different from the pre-treatment values. Latency of the VEP N1 wave showed a slight prolongation, which might be secondary to the depression of retinal function. Histological examination showed swelling and proliferation of the lens epithelium and swelling and vacuolization of the lens fiber were observed in the eyeball 9 weeks after STZ-treatment. Moreover, thinning of each retinal layer was observed in a few rats. Daily s.c. injection of insulin at 10 units/rat/day started from the 4th week. The ERG values returned to the control values after 2-3 weeks of insulin therapy. These results indicate that the ERG and VEP recording procedure used in the present study is useful for early detection of the diabetic retinopathy in rats and that the OP of the ERG appears to be vulnerable to diabetes in the rat as it is in the human.

Animals↗

A pathological study in cynomolgus monkeys infected with Edesonfilaria malayensis.

The host response to natural infection with Edesonfilaria malayensis in six female adult cynomolgus monkeys (Macaca fascicularis) imported from Indonesia was examined retrospectively by histopathology and clinical investigations. Reduced values of hemoglobin and hematocrit, an increased number of eosinophils, an elevated level of total protein and a decrease in A/G ratio were noted in hematological and blood chemical examinations of the infected animals. The filarial worms inhabited subserosal connective tissues of the abdominal and the thoracic cavities but not the lumina of the body cavities. There was thickening of the connective tissues, hemorrhage and adhesion of the serosa in the site occupied by the worms and the cysts. Histopathologically, proliferation of the connective tissues and/or granulation tissues, infiltration of eosinophils, lymphocytes and other cells associated with inflammation and hemorrhage were observed. The worms occasionally caused mechanical damage in nearby tissues such as the pancreas and the iliopsoas muscle. In addition, splenic nodules were found in five of the six infected monkeys as a secondary lesion specifically related to the infection with Edesonfilaria malayensis.

Animals↗