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Biomedical subjects

T Otsuka

Publications and source records attributed to T Otsuka.

At least 217 records · Page 12Linked to original sources
PubMed1994

[Magnetic resonance imaging (MRI) of bone marrow necrosis].

Magnetic resonance (MR) of bone marrow was studied in two cases of acute leukemia which showed bone marrow necrosis. Case 1:A 24-year-old female was admitted because of sternum pain and bleeding tendency. She was diagnosed AML based on the peripheral blood picture. Bone marrow biopsy revealed the presence of bone marrow necrosis. T1 weighted imaging of MR showed low signal intensity in all vertebral marrow. Fatty marrow was demonstrated after achieving complete remission and the MR imaging of bone marrow changed to show high intensity, suggesting fat deposition. Case 2: A 19-year-old female suffered from chest pain and lumbago, and was diagnosed as ALL. DIC and bone marrow necrosis were confirmed during chemotherapy for remission induction. T1 weighted imaging showed the mosaic pattern of low and high signal intensity. She achieved complete remission and bone marrow clot revealed the presence of fatty marrow. Most areas of low signal intensity of T1 weighted imaging changed to those of high signal intensity. These observations suggest that necrotized bone marrow seemed to change to fatty marrow along with achieving remission. MR imaging study of bone marrow is useful for evaluating hematopoiesis in hematologic disorders.

Adult↗
PubMed1994

Myasthenia gravis after allogeneic bone marrow transplantation.

A 37-year-old Japanese man with chronic myeloid leukemia (CML) developed myasthenia gravis 29 months after bone marrow transplantation (BMT) from an HLA one locus-mismatched brother. Proximal muscle weakness and bilateral ptosis occurred along with the exacerbation of chronic GVHD shortly after sudden cessation of cyclosporine (CYA) and prednisolone. The diagnosis of myasthenia gravis was made based on clinical symptoms and elevation of an anti-acetylcholine receptor antibody titer and all symptoms related to myasthenia gravis promptly diminished with the start of treatment for chronic GVHD. In most previously reported cases, the underlying disease was aplastic anemia (6 of 7 cases) and donors were of the opposite sex (6 of 7 cases). The haplotypes HLA B7 (3 of 5 cases), B35 (3 of 5 cases), and DR2 (3 of 3 cases) were common. All cases suffered from chronic GVHD. The present case had only chronic GVHD and HLA B7 as a background for myasthenia gravis after BMT. The abrupt cessation of immunosuppressive therapy may also be related to the development of myasthenia gravis after BMT.

Adult↗
PubMed1994

[A case report of obstructive sleep apnea syndrome associated with primary aldosteronism].

A 60-year-old obese woman was admitted for evaluation of excessive daytime sleepiness, loud snoring, cyanosis, systemic edema, hypertension and diabetes mellitus. Laboratory examination showed severe hypoxemia, hypercapnea, metabolic alkalosis, hypokalemia and hyperaldosteronism. CT scan showed a left adrenal tumor. A diagnosis of obstructive sleep apnea syndrome associated with primary aldosteronism was established. Metabolic alkalosis, hypokalemia and sodium retention due to hyperaldosteronism were thought to be factors exacerbating her sleep apnea.

Female↗
PubMed1994

Studies on the antiviral activity of propagermanium with immunostimulating action.

The effects of propagermanium (3-oxygermylpropionic acid polymer) on various virus-infected mice were investigated. Propagermanium did not inhibit the multiplication of various DNA or RNA viruses in vitro. Oral administration of propagermanium in mice infected with herpes simplex virus type I (HSV-1) significantly prolonged the mean survival days. The efficacy of propagermanium at doses of 1 and 10 mg/kg daily was 13.4 +/- 2.3 and 14.2 +/- 2.3 mean survival days in comparison with 7.7 +/- 0.5 mean survival days at control group. In vaccinia virus-infected mice, oral doses of propagermanium ranging from 0.2 to 10 mg/kg suppressed the number of pocks on the tail which induced by the virus. Propagermanium (0.5-10 mg/kg) orally given to HSV-1-infected mice induced cytotoxic T lymphocytes (CTL) against HSV-1 antigen. In addition, propagermanium (1-10 mg/kg) enhanced interferon-gamma (IFN-gamma) induction in mice treated with Mycobacterium bovis (BCG). In mice spleen cells cultured with Concanavalin A, 0.1 to 10 micrograms/ml of propagermanium stimulated interleukin 2 (IL-2) production. It seems likely that the antiviral activity of propagermanium was exerted via enhancement of host immune resistance against viral infection.

Adjuvants, Immunologic↗
PubMed1993

High concentrations of immunoreactive gliostatin/platelet-derived endothelial cell growth factor in synovial fluid and serum of rheumatoid arthritis.

Since neovascularization plays an important role in the propagation of rheumatoid synovitis, we analyzed the concentration of gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF), a potent angiogenic and chemotactic factor, in the synovial fluid and serum of rheumatoid arthritis (RA) patients. The immunoreactive GLS/PD-ECGF concentrations (mean value +/- S.D.) in synovial fluid, measured by a sandwich enzyme immunoassay, were significantly higher in RA patients than in osteoarthritis (OA) patients (233.02 +/- 219.40 vs. 9.09 +/- 14.86 ng/g, P < 0.001), and the serum concentrations were also higher in RA patients than in age-matched controls (8.77 +/- 7.60 vs. 3.74 +/- 2.61 ng/ml, P < 0.005). These results suggest that GLS/PD-ECGF may participate in the endothelial proliferation resulting in initiation of the extensive emigration of mononuclear cells and proliferation of the synovial tissues in rheumatoid arthritis, and that the immunoreactive GLS/PD-ECGF in serum as well as synovial fluids may be a useful diagnostic marker of RA.

Arthritis, Rheumatoid↗
PubMed1993

Establishment of an enzyme immunoassay system for gliostatin/platelet-derived endothelial cell growth factor (PD-ECGF).

A two-site enzyme immunoassay for gliostatin (GLS)/platelet-derived endothelial cell growth factor (PD-ECGF) has been developed. The detection limit of gliostatin/PD-ECGF was 30 pg/well, and the optimal assay range was 0.1 to ng/well. This assay system enabled us to confirm the immunochemical identity of both factors and to detect immunoreactive gliostatin/PD-ECGF (IR-GLS/PD-ECGF) in human biological body fluids. The age-related analysis from newborn to 69 years revealed that the serum IR-GLS/PD-ECGF level was high in infants younger than 1 year old (1.8 ng/ml) and in the 20-year-old age group (1.8 ng/ml), and highest in the umbilical cord blood (2.1 ng/ml). Curiously high concentrations were detected in saliva with a significant sex difference (11.3 ng/ml for males and 48.7 ng/ml for females), and in synovial fluids (3.7 ng/ml). A number of human tumor cells, gastric cancer cells, MKN-74, neuroblastoma cells, GOTO, as well as epidermoid carcinoma cells, A431, were found to produce a significant amount of IR-GLS/PD-ECGF (0.2 to 21.8 ng/mg protein), and some of them secreted the IR-GLS/PD-ECGF in the conditioned medium (approximately 0.5 ng/ml). The enzyme immunoassay system is sufficiently sensitive for the basic and clinical study of gliostatin/PD-ECGF in human body fluids, tissues and organs.

Adolescent↗
PubMed1993

Meiotic mutations from natural populations of Drosophila melanogaster.

Two meiotic genes from natural populations are described. A female meiotic mutation, mei(1)g13, mapped to 17.4 on the X chromosome, causes nondisjunction of all homologs except for the fourth chromosomes. In addition, it reduces recombination by 10% in the homozygotes and causes 18% increased recombination in the heterozygotes. A male meiotic mutation, mei-1223m144, is located on the third chromosome. Although this mutation causes nondisjunction of all chromosomes, each chromosome pair exhibits a different nondisjunction frequency. Large variations in the sizes of the premature sperm heads observed in the homozygotes may reflect irregular meiotic pairing and the subsequent abnormal segregation, resulting in aneuploid chromosome complements.

Animals↗
PubMed1993

Hypoxia increases velocity of blood flow through parenchymal microvascular systems in rat brain.

The postulation that hypoxia increases local cerebral blood flow (lCBF) mainly by perfusing more capillaries (the capillary recruitment hypothesis) was tested in awake adult male Sprague-Dawley rats exposed to 10% O2 and control rats. The [14C]iodoantipyrine technique was used to measure lCBF. Local cerebral blood volume was determined by measuring plasma and red cell distribution spaces within the brain parenchyma with 125I-labeled serum albumin (RISA) and 55Fe-labeled red cells (RBC), respectively. Tissue radioactivity in 44 brain areas was estimated by quantitative autoradiography. Hypoxia raised lCBF by 25-90% in all brain areas. In about one-quarter of the brain areas, the rise in blood flow was associated with a small increase in microvascular plasma and blood volumes. This change in blood volume, which could be the result of perfusing more parenchymal microvessels and/or increasing parenchymal microvessel diameter, is not sufficient to account for the observed rise in lCBF. In the remaining areas the RISA, RBC, and blood spaces were either unchanged or only marginally increased by hypoxia. For this hypoxic perturbation, the major mechanism of raising blood flow appears to be increased velocity of microvessel perfusion and not perfusion of more capillaries. These findings provide only limited support for the capillary recruitment hypothesis.

Animals↗
PubMed1993

The velocities of red cell and plasma flows through parenchymal microvessels of rat brain are decreased by pentobarbital.

Local cerebral blood flow is lowered in many brain areas of the rat by high-dose pentobarbital (50 mg/kg). In the present study, the mechanism of this flow change was examined by measuring the distribution of radiolabeled red blood cells (RBCs) and albumin (RISA) in small parenchymal microvessels and calculating the microvascular distribution spaces and mean transit times of RBCs, RISA, and blood. In most brain areas, pentobarbital slightly decreased the RISA space, modestly increased the RBC space, and did not alter the blood space. The mean transit times of RBCs, RISA, and blood through the perfused microvessels were considerably greater in treated rats than in controls. These findings indicate that the mechanism by which high-dose pentobarbital diminishes local cerebral blood flow in rat brain is, in the main, a lowered linear velocity of plasma and RBC flow through small parenchymal microvessels and not decreased percentage of perfused capillaries (capillary retirement). This response is probably driven mainly by lowered local metabolism and may well entail a slight increase in the number of small microvessels that are perfused by RBCs.

Animals↗
PubMed1993

[Relationship between coagulase toxin-type and drug susceptibility in Staphylococcus aureus strains isolated in all the Japanese National University Hospitals].

Drug susceptibility of 430 Staphylococcus aureus strains isolated in 1991 from clinical specimens at all of the Japanese national university hospitals was evaluated in relationship with the epidemiological markers, namely, coagulase typing, and staphylococcal enterotoxins (SE) and toxic shock syndrome toxin 1 (TSST-1) production. There were five major methicillin-resistant Staphylococcus aureus (MRSA) groups in all the 252 MRSA strains: coagulase-type II-SEC + TSST-1- producing strains (II-SEC + TSST-1): 34.5%; coagulase-type II-no toxin-producing strains (II-): 15.4%; coagulase-type IV-SEA-producing strains (IV-SEA): 10.3%; coagulase-type II-SEA + SEC + TSST-1- producing strains (II-SEA + SEC + TSST-1): 8.7%; and coagulase-type III-no toxin-producing strains (III-): 7.1%. II-SEA + SEC + TSST-1 group was highly resistant to OFLX, whereas half of the other strain groups were sensitive to OFLX. Seventy-eight percent of the IV-SEA group was sensitive to FMOX, but there was no sensitive strain to FMOX in the II-SEA + SEC + TSST-1 group. More than 50% of the IV-SEA, III- and II-groups were sensitive to IPM, while the II-SEC + TSST-1 and II-SEA + SEC + TSST-1 groups were highly resistant to IPM. The III- and II-groups showed very good sensitivity to MINO, but the sensitivity to it of the II-SEA + SEC + TSST-1 group was very low. All of the strain groups were sensitive to ST except for the IV-SEA group. These results may provide useful information in the choice of antibacterial agents for MRSA infection.

Bacterial Toxins↗