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Biomedical subjects

Y Kuroda

Publications and source records attributed to Y Kuroda.

At least 739 records · Page 41Linked to original sources
PubMed1991

Reduced midbrain and pons size in children with autism.

Recent reports suggested functional abnormalities of the brain stem in autistic children. Moreover, structural brain abnormalities have also been reported, so we analyzed magnetic resonance imaging (MRI) scan in autistic children. MRI scans for 29 autistic children were compared with 15 control MRI scans. The midbrain and pons were measured. The midbrain and pons size were found to be significantly smaller in the autistic group. This suggests that the structure of the brain stem is anatomically altered in autistic children.

Autistic Disorder↗
PubMed1991

[Burkitt's type ALL with numb chin syndrome as an initial manifestation].

A case of Burkitt's type ALL with numb chin syndrome as the initial manifestation is described. A 57-year-old Japanese male was admitted to our hospital in November 14, 1989 because of paresthesia at the chin and lower lip with diplopia and ptosis. Neurological examination revealed oculomotor paralysis of the right side and hypesthesia on the chin, lower lip and buccal mucous membrane. Laboratory findings showed increased leukocyte count. Bone marrow aspirate revealed hypercellular marrow with 92.3% leukemic cells which had vacuoles in the cytoplasm and surface marker of IgM, kappa type. The abnormalities of karyotype included t(8;14). He was treated with chemotherapy and radiation. His conditions were temporarily improved, but relapsed later and died in March 6, 1990. Leukemic infiltrations to the trigeminal nerve were found in autopsy. The relationship between lymphoid malignancies and numb chin syndrome was discussed.

Burkitt Lymphoma↗
PubMed1991

Acute tubulointerstitial nephritis associated with Yersinia pseudotuberculosis infection.

Two siblings infected with Yersinia pseudotuberculosis suffered from acute renal failure about 2 weeks after the onset of the disease. Renal histology in both siblings showed acute tubulointerstitial nephritis. Yersinia pseudotuberculosis type VB was isolated from feces of one of them, antibodies to Yersinia pseudotuberculosis type VB in their sera were elevated. The results of the present study suggest that acute renal failure complicating infections with Yersinia pseudotuberculosis is due to acute tubulointerstitial nephritis.

Acute Kidney Injury↗
PubMed1990

Effects of recombinant human G-CSF, GM-CSF, IL-3, and IL-1 alpha on the growth of purified human peripheral blood progenitors.

The effects of recombinant products of granulocyte colony-stimulating factors (G-CSF), granulocyte/macrophage CSF (GM-CSF), human interleukin-3 (IL-3), and interleukin-1 (IL-1) were studied using purified target cell populations from patients undergoing peripheral blood stem cell transplantation after myeloablative therapy. Cells were subjected to combined purification procedures including negative selection with a panel of monoclonal antibodies (CD2, 3, 5, 10, and 20). The purified cells were enriched for HLA-DR+ (51% to 71%) and My-10+ (CD34; 37% to 54%) and had a plating efficiency of up to 20%. In the liquid-suspension limiting dilution clonal assay (LDA), purified progenitors responded directly to IL-3 by proliferation with single-hit kinetics. The ability of GM-CSF to support progenitor growth was inferior to that of IL-3, and the cells were virtually unresponsive when cultured with G-CSF, supporting the notion that these blood-derived progenitors belong to a primitive population of hematopoietic progenitor cells. The results obtained in simultaneous methycellulose cultures (MC) showed the same trend and provided additional information on the ability of GM-CSF and IL-3 to support erythroid progenitor growth. The combination of IL-3 plus G-CSF, but not IL-3 plus GM-CSF, resulted in a synergistic increase in colony number. IL-1 alpha increased both the size and number of colonies when added to IL-3 or G-CSF. Study of this enriched progenitor cell population in MC and LDA represents an excellent model for the investigation of myeloid and erythroid differentiation and for evaluating the influence of various cytokines on human hematopoiesis.

Antigens, CD↗
PubMed1990

Stereoselective determination of free warfarin concentration in protein binding equilibrium using direct sample injection and an on-line liquid chromatographic system.

A new on-line high-performance liquid chromatography system was developed for the stereoselective determination of free drug concentration in drug-protein binding equilibrium. When a 40-300-microL portion of a sample solution containing 50-200 microM racemic warfarin (Wf) and 100-550 microM human serum albumin was directly injected into the internal-surface reversed-phase silica column, Wf gave a trapezoidal peak exhibiting a plateau region. The concentration in the plateau region was equal to the free Wf concentration in the initial sample solution. By the delivery of a portion (90 microL) of the eluent in the plateau region into the chiral separation column (Chiral AGP column) by column switching, the free concentrations of respective enantiomers of Wf were determined. The results agreed well with those obtained by the conventional ultrafiltration method. The precision was also confirmed by the within-run and day-to-day reproducibilities (coefficient of variation less than or equal to 3.05%, n = 5). The present method is simple and rapid and four sample solutions can be analyzed within 1 h without pretreatment.

Chromatography, High Pressure Liquid↗
PubMed1990

Antimutagenic activity of vitamins in cultured mammalian cells.

Cultured mammalian cell systems are useful for examining the quantitative effects of mutagens and antimutagens on cell survival and gene mutations and the mechanisms of the interaction of two chemicals in the process of mutation induction. In the present article, the antimutagenic effects of vitamins C, E, and A, and derivatives of vitamin C on EMS-induced 6TG-resistant mutations in Chinese hamster V79 cells were examined. Vitamin C was most effective in inhibiting EMS-induced cytotoxicity and 6TG-resistant mutations. In the presence of vitamin C at a concentration of 100 micrograms/ml, EMS-induced mutations were reduced to about one-third or one-fourth of those in control cultures treated with EMS alone. Dehydro-vitamin C and iso-vitamin C also inhibited EMS-induced mutations to about one-half or one-third of the control level. The fact that vitamin C was effective in reducing EMS-induced mutations when EMS was previously incubated together with vitamin C for 3 hr suggests that vitamin C may react directly with EMS as a desmutagen and thus inactivate its mutation-inducing activity in Chinese hamster V79 cells. Vitamin E had an additive cytotoxic effect on EMS-induced cytotoxicity. This vitamin enhanced the frequencies of 6TG-resistant mutations induced by EMS. Pretreatment with vitamin E before treatment with EMS resulted in no detectable effect in modifying the EMS-induced mutations. On the contrary, vitamin A markedly enhanced EMS-induced mutation frequencies.

Animals↗
PubMed1990

Entrapment of left renal vein in children with orthostatic proteinuria.

We found that patients with orthostatic protein-uria had entrapment of the left renal vein (LRV) by the aorta and superior mesenteric artery (SMA). Of 15 patients studied, ultrasonographic examination showed 13 cases of typical LRV entrapment with prestenotic dilatation, and 2 cases of mild LRV compression between the aorta and SMA. Intra-arterial digital subtraction angiography and monitoring of pull-back pressure from LRV to the inferior vena cava (IVC) were performed on 2 patients with 4+ proteinuria. Accumulation of contrast medium was seen with mild back-flow to the collateral veins, and pressure gradients between LRV and IVC were 4 mmHg and 8 mmHg, respectively. Eighty school-children formed a control group and were investigated ultrasonically. Nine showed typical LRV entrapment, among whom 3 had moderate to massive orthostatic proteinuria. The discovery of LRV entrapment in patients with orthostatic proteinuria gives definite evidence of LRV congestion and may be possibly a cause of massive protein secretion from the left kidney.

Adolescent↗
PubMed1990

Subchronic administration of para-chlorophenylalanine enhances serotonin-stimulated phosphoinositide hydrolysis in rat hippocampal slices.

Serotonin (5-HT) caused a dose-dependent accumulation of inositol monophosphate (IP-1) in rat hippocampal slices (maximal effect + 172%, EC50 = 630 nM) in the presence of LiCl. The 5-HT response was blocked potently by a non-selective 5-HT receptor antagonist metergoline and a 5-HT1C/5-HT2 receptor antagonist ritanserin. The 5-HT2 receptor antagonist ketanserin and spiperone were, however, less potent at inhibiting the 5-HT response. m-Chlorophenylpiperazine (mCPP), a 5-HT1C receptor agonist but a 5-HT2 antagonist stimulated directly PI turnover, yet mCPP inhibited 5-HT-stimulated PI response. These findings indicate that both 5-HT1C and 5-HT2 receptors are involved with a complicated interaction of each receptor in 5-HT-stimulated PI hydrolysis in rat hippocampus. 10-Day treatment with para-chlorophenyl-alanine (PCPA), a 5-HT synthesis inhibitor, resulted in a significant increase (maximal effect + 225%, EC50 = 580 nM) in 5-HT-stimulated IP-1 accumulation with no substantial change in EC50 value, which suggest that subchronic treatment with PCPA enhances the 5-HT-mediated PI hydrolysis in rat hippocampus.

Animals↗
PubMed1990

The long-term function and histology of segmental pancreatic autografts with pancreatic exocrine diversion to the esophagus in dogs.

The endocrine function and histology of segmental pancreatic autografts with pancreatic exocrine diversion to the esophagus were assessed in nine dogs which survived longer than three years. An original twelve dogs underwent total pancreatectomy followed by a segmental pancreatic graft autotransplanted with pancreatic duct to esophagus anastomosis in the neck. All twelve dogs immediately had normal fasting glucose, nine of which sustained it for more than three years. One of the twelve dogs died on the tenth day from a thrombosis and two others died of causes unrelated to the graft; one of pneumonia and the other of an unknown cause, within the first year of transplantation. An intravenous glucose tolerance test performed three years after the transplantation revealed K values (1.90 +/- 0.37) which were not significantly different from those tested before the transplantation (1.92 +/- 0.42). The patency of the anastomosis between the pancreatic duct and the esophagus was clearly identified in the specimen of a dog sacrificed three years after the transplantation. The mucosa of the esophagus was macroscopically and microscopically almost normal. Histological studies of the autografts done three years after the transplantation showed almost normal pancreatic architecture in the islets and exocrine tissues, while histochemical analysis with immunoperoxidase stains confirmed the presence of insulin, glucagon and somatostatin. It is therefore possible that this new technique could be used for clinical segmental pancreatic transplantation.

Anastomosis, Surgical↗
PubMed1990

Impairment of cell-mediated immune responses in HTLV-I-associated myelopathy.

In order to assess in vivo cell-mediated immune functions in HTLV-I-associated myelopathy (HAM), we immunized 18 HAM patients with dinitrochlorobenzene (DNCB). Of 18 patients, the skin reaction to DNCB was negative in 15. All those 15 patients also showed anergy to PPD-tuberculin and 9 of 15 patients had a persistent lymphocytopenia (less than 1500/mm3). In vitro lymphoproliferative responses to mitogens, assayed by a flow fluorocytometric method, were also significantly depressed in HAM patients when compared to normal controls. The results thus indicate that cell-mediated immune functions are significantly impaired in HAM patients.

Deltaretrovirus Antibodies↗
PubMed1990

Hereditary pressure-sensitive neuropathy: demonstration of "tomacula" in motor nerve fibers.

By studying intramuscular nerves in 2 patients from 2 families with hereditary pressure-sensitive neuropathy (HPSN), the occurrence of abnormal thickening of myelin sheaths ("tomacula") was for the first time demonstrated in motor nerve fibers. Furthermore, the tomacula were found to line up on certain axons instead of being randomly distributed. These results indicate that the recurrent mononeuropathies of HPSN arise from an underlying asymptomatic motor and sensory polyneuropathy. It is also suggested that some signals emanating from the axons might be related to the formation of tomacula on the basis of the genetically determined myelination disorder.

Adolescent↗
PubMed1990

Antimutagenic action of cobaltous chloride on radiation-induced mutations in cultured Chinese hamster cells.

The effects of cobaltous chloride on 8-azaguanine (8AG)-resistant mutations induced by gamma-rays or ultraviolet (UV) light in cultured Chinese hamster V79 cells were examined. Cobaltous chloride alone had no significant effects on survival and mutations of V79 cells at concentrations less than 1 x 10(-5) M. Cobaltous chloride at a concentration of 3 x 10(-6) M had a marked effect in reducing 8AG-resistant mutations induced by gamma-rays of 2-6 Gy, when cells were incubated for 6-7 days in the presence of cobaltous chloride after gamma-ray irradiation (posttreatment). The pretreatment of cells with cobaltous chloride for 6 days before gamma-ray irradiation reduced 8AG-resistant mutations induced by gamma-rays. Pre- or post-treatment with cobaltous chloride had no such effect on UV-induced mutations, however. The difference in responsiveness to cobaltous chloride between bacterial and mammalian cell systems is discussed.

Animals↗
PubMed1990

Cranial MR imaging in patients with von Recklinghausen's disease (neurofibromatosis type I).

MR imaging was performed for 24 patients with von Recklinghausen's disease. Twenty of the 24 patients showed abnormal findings in MR imaging. In many cases, the lesions were multifocal. In 14 patients small focal areas of increased signal on T2-weighted images were thought to represent heterotopias or hamartomas. Eight patients had optic tract gliomas. Three patients had parenchymal gliomas. In one patient, white matter showed high intensity on T2-weighted images representing delayed myelination. The rate of abnormal findings was higher for MR imaging than CT. MR imaging was found to be an excellent imaging method for known diseases and for detecting lesions in asymptomatic patients.

Adolescent↗
PubMed1990

Epidural bupivacaine suppresses local glucose utilization in the spinal cord and brain of rats.

Using the 2-[14C]deoxyglucose method, the effects of analgesic doses of epidural bupivacaine (300 micrograms) on local spinal cord glucose utilization (SP-LGU) of the cervical, thoracic, and lumbar regions and local cerebral glucose utilization (BR-LGU) in 38 brain structures were examined in conscious rats. In addition, the effects of intramuscular bupivacaine (300 micrograms) and the spinal cord transection (T2) were examined to determine whether the induced metabolic changes, if any, are related to the drug's systemic effect and/or deafferentation. Lumbar epidural bupivacaine sufficient to produce analgesia decreased SP-LGU in the thoracic (18-28%) and lumbar (21-29%) spinal cord but not in the cervical cord. Epidural bupivacaine decreased BR-LGU (15-26%) in 35 of 38 structures examined. With intramuscular bupivacaine, SP-LGU remained unchanged in almost all regions, while BR-LGU was significantly decreased (11-23%) in 23 structures. Plasma concentrations of bupivacaine in the epidural and intramuscular groups were comparable. With spinal cord transection alone, SP-LGU significantly decreased with varying degrees depending on the structure examined, but BR-LGU did not decrease in 36 of 38 structures examined. These results indicate that analgesic doses of epidural bupivacaine decrease SP-LGU, probably reflecting decreased neuronal activity of the spinal cord, and that reduced BR-LGU by epidural bupivacaine is most likely due to the drug's systemic effect rather than deafferentation.

Analgesia, Epidural↗