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Biomedical subjects

N Harada

Publications and source records attributed to N Harada.

At least 415 records · Page 23Linked to original sources
PubMed1993

Bcl-2 gene is highly expressed during neurogenesis in the central nervous system.

An analytical method for quantitation of the RNA transcripts of murine bcl-2 gene was developed. The PCR products from bcl-2 alpha and bcl-2 beta mRNA were fluorometrically analyzed and their specific contents were calculated by the internal standard method. Both bcl-2 mRNAs in adult mice were transcribed at the highest level in the thymus and at a comparable level in the spleen. Aside from the immune system, the brain gave the most abundant levels of the bcl-2 mRNAs. The ratios of bcl-2 beta mRNA to bcl-2 alpha mRNA in the thymus and spleen were significantly higher than those in other tissues. During development of the brain, the bcl-2 alpha and bcl-2 beta mRNA levels were highest on embryonic day 15, and about two and three times higher than those of adult, respectively. The results suggest that the bcl-2 gene functions to regulate development and survival of neurons in the central nervous system.

Animals↗
PubMed1993

The chimeric receptor between interleukin-2 receptor beta chain and interleukin-4 receptor transduces interleukin-2 signal.

Transfectants expressing the chimeric receptor which has human interleukin-4 receptor (hIL-4R) in the extracellular domain and human interleukin-2 receptor beta chain (hIL-2R beta) in the cytoplasmic domain showed continuous growth in response to human interleukin-4 (hIL-4), whereas transfectants expressing hIL-4R responded only transiently to hIL-4. The pattern of tyrosine phosphorylation induced by hIL-4 in transfectants expressing the chimeric receptor was very similar to that in transfectants expressing hIL-2R beta, but different from that in transfectants expressing hIL-4R, indicating that the chimeric receptor transduces the interleukin-2 like growth signal by hIL-4.

Animals↗
PubMed1993

Antibodies to murine CD40 stimulate normal B lymphocytes but inhibit proliferation of B lymphoma cells.

A rat anti-mouse CD40 antiserum has been prepared by hyperimmunisation of Lewis rats with a highly purified preparation of the recombinant extracellular domain of murine CD40. This antiserum specifically binds CD40-expressing L cell transfectants, but not untransfected L cells, and induces vigorous proliferation of highly purified small dense B cells obtained from the spleens of unstimulated mice. Anti-CD40-induced B cell proliferation can be augmented by the addition of IL-4 and is inhibited by purified recombinant soluble mouse CD40. Interestingly the same anti-CD40 antiserum specifically inhibits the in vitro growth of A.20 murine B lymphoma cells. The specificity of this inhibition can be demonstrated by reversing the effect with purified recombinant soluble mouse CD40. These data implicate CD40 as a possible target for therapeutic intervention in the treatment of B lymphomas.

Animals↗
PubMed1993

Ascorbate radical levels in human sera and rat plasma intoxicated with paraquat and diquat.

To clarify the toxicological mechanism of action of paraquat and diquat, the level of ascorbate radical, an oxidized product of ascorbic acid, was examined using the electron spin resonance (ESR) method. The ascorbate radical level increased to twice the normal level in sera from humans acutely intoxicated with a 1:1 mixture of paraquat and diquat, and to more than 1.5 times the normal level in rat plasma containing moderate levels of paraquat. The dosage level for rats was 0.025% paraquat dichloride in the diet. The ascorbate radical in both intoxicated human sera and rat plasma decayed much faster than that in normal samples.

Aged↗
PubMed1993

Genetic analysis of human placental aromatase deficiency.

Placental aromatase deficiency, which was characterized by maternal and fetal virilization and by a low level of estrogen excretion into urine during pregnancy, was studied by biochemical and molecular genetical techniques. Among enzymes participating in the electron transport system of the patient's placental microsomes, only aromatase activity was observed to be reduced (< 3% of normal levels). Northern and Western blotting analyses showed that the transcription of the aromatase gene and the translation of its mRNA seemed to proceed normally in the patient's tissue. However, the aromatase cDNA isolated from the patient was found to contain an extra DNA fragment of 87 base pairs (bp) which encoded 29 amino acids in frame but no termination codon. The insertion was located at the splicing point between exon 6 and intron 6 of the normal aromatase gene. The extra DNA fragment represented the first part of intron 6 except that its initial GT was altered to GC. These findings indicated that, in the patient's aromatase gene, the splicing between exon 6 and intron 6 did not occur at the normal position. This reflected the presence of one point mutation in its consensus sequence which caused the next cryptic consensus sequence 87 bp downstream, to be used according to the canonical GT/AG rule. The protein molecule thus translated contained an extra 29 amino acids. Furthermore, the patient's aromatase cDNA was observed to produce a protein molecule with a trace of activity in the transient expression system of COS-7 cells and in the high level expression system of baculovirus-insect cells. Direct DNA sequencing of aromatase genes from the patient and parents confirmed that this deficiency is a hereditary disease with an autosomal recessive inheritance pattern. The patient and parents are homozygote and heterozygotes, respectively, for this mutation.

Amino Acid Sequence↗
PubMed1993

Aromatase immunoreactivity in the rat brain: gonadectomy-sensitive hypothalamic neurons and an unresponsive "limbic ring" of the lateral septum-bed nucleus-amygdala complex.

The aromatase (estrogen synthetase) enzyme catalyzes the conversion of androgens to estrogens in peripheral tissues, as well as in the brain. Our study aimed at comparing the brain distribution of aromatase-immunoreactive neurons in male and female, normal and gonadectomized rats. Light microscopic immunostaining was employed using a purified polyclonal antiserum raised against human placental aromatase. Two anatomically separate aromatase-immunoreactive neuronal systems were detected in the rat brain: A "limbic telencephalic" aromatase system was composed by a large population of labeled neurons in the lateral septal area, and by a continuous "ring" of neurons of the laterodorsal division of the bed nucleus of stria terminalis, central amygdaloid nucleus, stria terminalis, and the substantia inominata-ventral pallidum-fundus striati region. The other, "hypothalamic" aromatase system consisted of neurons scattered in a dorsolateral hypothalamic area including the paraventricular, lateral and dorsomedial hypothalamic nuclei, the subincertal nucleus as well as the zona incerta. In addition, a few axon-like processes (unresponsive to gonadectomy) were present in the preoptic-anterior hypothalamic complex, the ventral striatum, and midline thalamic regions. No sexual dimorphism was observed in the distribution or intensity of aromatase-immunostaining. However, 3 days, 2, 3, 8, 16, or 32 weeks after gonadectomy, aromatase-immunoreactive neurons disappeared from the hypothalamus, whereas they were still present in the limbic areas of both sexes. The results indicate the existence of two distinct estrogen-producing neuron systems in the rat brain: (1) a "limbic ring" of aromatase-labeled neurons of the lateral septum-bed nucleus-amygdala complex unresponsive to gonadectomy; and (2) a sex hormone-sensitive "hypothalamic" aromatase neuron system.

Amygdala↗
PubMed1993

Human macrophage colony-stimulating factor levels in cerebrospinal fluid.

Macrophage colony-stimulating factor (M-CSF) levels in the cerebrospinal fluid of 14 patients with meningitis and of 14 patients suffering from a disease other than meningitis were measured using an enzyme-linked immunosorbent assay. All four bacterial meningitis patients had M-CSF levels in the cerebrospinal fluid which exceeded 1540 U/ml, and the mean value was 3333 +/- 1481 U/ml. The mean M-CSF level in the cerebrospinal fluid of the ten aseptic meningitis patients was 393 +/- 175 U/ml, which was higher than that of patients who suffered from a disease other than meningitis (179 +/- 90 U/ml) (P < 0.01). There was no clear correlation between the M-CSF levels and the numbers of white blood cells, granulocytes, or monocytes in the cerebrospinal fluid. These elevated M-CSF levels were thought to be of a local origin, since most patients with high M-CSF levels in the cerebrospinal fluid had relatively low M-CSF levels in the serum.

Adult↗
PubMed1993

Fc gamma receptor-mediated biological activities of human leukemic cell lines and their modulation by transforming growth factor-beta 1 and interleukin 6.

Previously we reported that transforming growth factor-beta 1 (TGF-beta 1) remarkably enhanced the differentiation of human leukemic cell lines, HL-60 and THP-1, in the presence of 1 alpha,25-dihydroxyvitamin D3 (VD3) and also that it induced Fc receptor for immunoglobulin G (Fc gamma R), type IIIB, in the presence of retinoic acid (RA). The present study revealed that TGF-beta 1 enhanced the Fc gamma RI- and Fc gamma RII-mediated antibody-dependent cellular cytotoxicity (ADCC) of the cells differentiated in the presence of VD3 and RA. However, production of active oxygen molecules was suppressed by TGF-beta 1. On the other hand, IL-6 stimulated production of active oxygen molecules and ADCC of the cells treated with VD3 and tumor necrosis factor-alpha (TNF-alpha). Furthermore, the levels of cell surface Fc gamma RI and Fc gamma RII were not clearly correlated with the ADCC. The TGF-beta 1/VD3-treated HL-60 cells were able to synthesize mRNAs for TGF-beta 1 and TNF-alpha, although TNF-alpha protein was not detectable. These results suggest that TGF-beta 1 has a bifunctional role, either stimulatory or inhibitory, in the modulation of macrophage activities through Fc gamma Rs and that IL-6 stimulates certain macrophage activities in mature cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1993

Functional status outcomes in rehabilitation. Implications for prospective payment.

Previous studies have demonstrated that functional status is a significant predictor of resource utilization for rehabilitation patients. Before implementing a prospective payment system (PPS) for rehabilitation, it is important to first: 1) develop an underlying conceptual framework of rehabilitation resource use; and 2) understand how the role of functional status may vary by rehabilitation condition. In this study, a theoretical model of rehabilitation is presented that proposes relationships between patient and provider characteristics, rehabilitation treatment, costs, and clinical outcomes of rehabilitation. Also presented are regression analyses based on this model for a key outcome of rehabilitation, change in functional status, for nine rehabilitation conditions using variables that minimize adverse incentives by providers in selecting patients for admission to rehabilitation. The change-in-functional-status model explained the most variance for back injury, cardiopulmonary, and arthritis, and less variance for stroke, spinal cord injury, and neurologic impairment. The significant predictors of change in functional status varied by condition. Results support the use of functional status measurements in a PPS for rehabilitation services, the need to refine the measurement of functional status, and the use of condition-specific activities of daily living (ADL) items to include in summary indices.

Activities of Daily Living↗
PubMed1993

Prenatal diagnosis of fragile X syndrome by direct detection of the dynamic mutation due to an unstable DNA sequence.

The fragile X syndrome is the most common familial form of mental retardation. The mutation causing the syndrome is dynamic mutation due to an unstable DNA (CCG)n repeat localized at Xq27.3. We have previously reported a PCR procedure to prepare a diagnostic probe, pPCRfx1, which can be used to determine the genotype of fragile X mutation individuals by Southern blot analysis. In the present study, pPCRfx1 was applied to the prenatal diagnosis, using chorionic villus cells, of a fetus which was at risk of having fragile X syndrome. In the PstI assay, the Southern blot showed the typical pattern of a female carrier with the full mutation. Analysis of the DNA methylation patterns by EcoRI + EagI assay showed that the EagI restriction site was not methylated on the mutated X chromosome of chorionic villi, but the sites were totally methylated in the brain and other tissues of the fetus. Thus the fetus was diagnosed to be a heterozygous female carrier of the dynamic mutation involved in the fragile X syndrome.

Blotting, Southern↗
PubMed1993

Measurement of redox states of mitochondrial cytochrome aa3 in regions of liver lobule by reflectance microspectroscopy.

To evaluate the sublobular distribution of oxygen tension, the redox states of mitochondrial cytochrome aa3 were assessed in local regions of the liver lobule by reflectance microspectroscopy. The reflected light from two focused microspots (20 microns in diam) on the surface of the perfused liver, placed on the stage of microscope, was conducted to the spectrophotometer with two separate light guides, giving the reflectance spectra. The redox state of cytochrome aa3 was calculated from the difference in reflectance between 603 and 630 nm. The degree of cytochrome reduction increased with the stepwise decline of the influent or effluent oxygen concentrations. The local oxygen concentration in periportal region for the half-maximal reduction of cytochrome aa3 was higher than that in pericentral region. In addition, the degree of cytochrome aa3 reduction increased with the distance from the periportal region, reflecting a physiological gradient of oxygen tension along the sinusoidal flow, although with an intersinusoidal heterogeneity within liver lobule.

Animals↗
PubMed1993

Identification of a functional receptor for granulocyte colony-stimulating factor on platelets.

Since granulocyte colony-stimulating factor (G-CSF) is thought to be a granulocyte lineage-specific cytokine, G-CSF receptors on blood cells other than those of granulocyte or monocyte lineage have not been well investigated. We now report that G-CSF receptors are present on platelets. The expression of G-CSF receptors on platelets was demonstrated by flow cytometry and radioreceptor assay. The mean number of G-CSF-binding sites per cell was 41 and the binding affinity was high (Kd 300 pM), similar to the affinity observed on granulocytes. Cross-linking assay revealed that G-CSF receptors were present on a single subunit protein of approximately 150 kD on the platelets. To clarify whether or not G-CSF might produce some direct functional influence on platelet response, the effects on platelet aggregation were studied. Although G-CSF itself did not affect platelet aggregation in vitro, preincubation with G-CSF augmented a secondary aggregation of platelets induced by low concentrations of adenosine diphosphate (ADP). There was a dose-response relationship for this G-CSF activity at concentrations of up to 10 ng/ml. Furthermore, the augmented ADP-induced secondary aggregation of platelets on G-CSF receptors was completely abrogated in the presence of anti-G-CSF polyclonal antibodies. These results indicate that platelets possess functional G-CSF receptors.

Adenosine Diphosphate↗
PubMed1993

Volume regulation in guinea pig outer hair cells and the role of intracellular calcium.

Single outer hair cells (OHCs) isolated from the guinea pig cochlea showed a regulatory volume decrease (RVD) after the initial cells swelling despite continued exposure to a hypotonic solution. The accompanying change of the intracellular Ca2+ concentration ([Ca2+]i) in the OHCs was investigated using the Ca(2+)-sensitive dye fura-2. Hyposmotic activation led to a [Ca2+]i increase which was accompanied by cell shortening and swelling. In a nominally Ca(2+)-free solution, however, [Ca2+]i was not significantly increased during hyposmotic activation although shortening and swelling of the OHCs were observed. These results suggest that the increase in [Ca2+]i during hyposmotic activation is mainly based on an influx of extracellular Ca2+.

Animals↗
PubMed1993

Calcium mobilization in isolated cochlear spiral ganglion cells of the guinea pig.

Single cochlear spiral ganglion cells (SGCs) were isolated using enzymatic and mechanical techniques. Intracellular free calcium ion concentrations ([Ca2+]i) in the SGCs were measured using a digital imaging microscope and the Ca(2+)-sensitive fluorescence dye fura-2. In the presence of the Ca2+ ionophore ionomycin (1 microM), there was an irreversible increase in [Ca2+]i. Depolarization by high K+ (150 mM) led to an increase in [Ca2+]i in SGCs, and this effect was reversible. The SGCs apparently possess voltage-gated calcium channels.

Animals↗
PubMed1993

[The importance of the host nutritional and immune status on the prognosis of urinary tract infection in the elderly].

This study was performed to evaluate the role of the nutritional and immune status on the prognosis of urinary tract infections (UTI) in the elderly. 192 patients among the 790 inpatients were diagnosed as UTI. Age-related increase in the prevalence of UTI was accompanied with poor prognosis in the patients with hypoalbuminemia (< 2.6 g/dl) and lymphocytopenia (< 700/mm3). To study the immunologic basis for susceptibility to UTI in the aged further, we compared the T-cell functions between outpatients without serious disease and inpatients with chronic UTI. The absolute numbers of lymphocyte, OKT3 (pan T-cell marker), OKT4 (Helper/Inducer marker) and Interleukin (IL)-2 as well as serum albumin concentration were decreased in the patients with UTI. A prospective study was done to confirm that these nutritional and immunological changes become risk factors in the prognosis of UTI with long-term and low-dose chemotherapy. In the patients continued with bacteriuria (Non-responders, n = 6), serum albumin concentration and IL-2 production were significantly lower than the patients who became free from bacteriuria (Responders, n = 7). These results suggest that poor nutrition-related immune dysfunction contributes to the vulnerability of elderly patients to UTI and becomes risks for he prognosis of UTI.

Adult↗