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Biomedical subjects

H Kawashima

Publications and source records attributed to H Kawashima.

At least 235 records · Page 13Linked to original sources
PubMed1992

[A case of giant prostatic calculi].

A 83-year-old man was admitted because of fever and painful swelling of the right scrotal contents on January 23, 1989. Kidney-ureter-bladder X-ray (KUB) showed multiple big prostatic calculi which were compressed postero-laterally by benign prostate hyperplasia (BPH) according to the CT film. UCG film revealed urethral stricture in the anterior urethra. He was diagnosed as having right epididymitis, urethral stricture, BPH and giant prostatic calculi. He was treated with right orchiectomy, urethral bougie and suprapubic prostatectomy with removal of the calculi. The total weight of the prostatic calculi was 28 g of consisted of 125 pieces. The postoperative course was uneventful and two years after the operation he has been well and free from evident disease.

Aged↗
PubMed1991

YM175, a new bisphosphonate, increases serum 1,25-dihydroxyvitamin D in rats via stimulating renal 1-hydroxylase activity.

Effect of YM175, a new bisphosphonate, on vitamin D metabolism was studied in rats. When animals were treated with the compound, serum 1,25-dihydroxyvitamin D increased in a dose dependent manner. The effect was also detected in thyroparathyroidectomized animals. The effect appears to be due to the stimulation of renal production of the hormone, since renal 1-hydroxylase was also elevated in these animals. However, when kidneys were incubated with YM175 and then renal 1-hydroxylase activity was examined, the enzyme activity was not different from that of non-treated control kidney. We conclude therefore that YM175 indirectly stimulates renal 25-hydroxyvitamin D-1-hydroxylase by increasing circulating parathyroid hormone via an unknown mechanism independent of parathyroid hormone. This is the first direct demonstration of increase in the renal production of 1,25-dihydroxyvitamin D resulting from bisphosphonate treatment.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1991

cDNA cloning and expression of the mRNA for cytochrome P-450kd which shows a fatty acid omega-hydroxylating activity.

We have recently purified three distinct forms of fatty acid omega-hydroxylase cytochrome P-450 (P-450), designated P-450ka-1, P-450ka-2 and P-450kd, from rabbit kidney cortex microsomes, and isolated and sequenced cDNA clones corresponding to P-450ka-1 and P-450ka-2 [Yokotani, N., Bernhardt, R., Sogawa, K., Kusunose, E., Gotoh, M., Kusunose, M. & Fujii-Kuriyama, Y. (1989) J. Biol. Chem. 264, 21,665-21,669]. The present paper describes cloning, sequencing and expression of a cDNA for the third fatty acid, omega-hydroxylase, P-450kd, from a rabbit kidney cDNA library. The cDNA for P-450kd encodes a polypeptide of 511 amino acids with sequence similarity of 87% to P-450ka-1. Its deduced NH2-terminal sequence of amino acids 5-24 is in complete agreement with the NH2-terminal sequence of P-450kd. The identity of the cDNA was further confirmed by its expression in COS-7 cells. When 14C-labeled lauric acid was added to the culture medium of COS-7 cells transfected with the cDNA, significant amounts of radioactive dodecanedioic acid, together with omega- and (omega-1)-hydroxylauric acids, were produced. Microsomes prepared from the transfected cells also efficiently catalyzed the omega- and (omega-1)-hydroxylation of lauric acid without formation of dodecanedioic acid. RNA blot analysis demonstrated that the mRNA for P-450kd gave a single band at the approximately 2.6-kb position. The mRNA for P-450kd was expressed in the liver and kidney, but not in many other tissues examined. Treatment of rabbits with clofibrate resulted in a elevated level of mRNA for P-450kd in both liver and kidney. Furthermore, the mRNA was remarkably increased in the kidney by the administration of cyclosporin A.

Amino Acid Sequence↗
PubMed1991

Sesamin is a potent and specific inhibitor of delta 5 desaturase in polyunsaturated fatty acid biosynthesis.

Incubation with sesame oil increases the mycelial dihomo-gamma-linolenic acid content of an arachidonic acid-producing fungus, Mortierella alpina, but decreases its arachidonic acid content [Shimizu, S., K. Akimoto, H. Kawashima, Y. Shinmen and H. Yamada (1989) J. Am. Oil Chem. Soc. 66, 237-241]. The factor causing these effects was isolated and identified to be (+)-sesamin. The results obtained in experiments with both a cell-free extract of the fungus and with rat liver microsomes demonstrated that (+)-sesamin specifically inhibits delta 5 desaturase at low concentrations, but does not inhibit delta 6, delta 9 and delta 12 desaturases. Kinetic analysis showed that (+)-sesamin is a noncompetitive inhibitor (Ki for rat liver delta 5 desaturase, 155 microM). (+)-Sesamolin, (+)-sesaminol and (+)-episesamin also inhibited only delta 5 desaturases of the fungus and liver. These results demonstrate that (+)-sesamin and related lignan compounds present in sesame seeds or its oil are specific inhibitors of delta 5 desaturase in polyunsaturated fatty acid biosynthesis in both microorganisms and animals.

Animals↗
PubMed1991

Effects of oleic, arachidonic and 5,8,11,14-nonadecatetraenoic acids on lipid secretion and ketogenesis in perfused rat liver.

The effects of perfused oleic (18:1n-9), arachidonic (20:4n-6) and 5,8,11,14-nonadecatetraenoic (19:4n-5) acids on triglyceride and cholesterol secretion and ketone body production were studied in isolated rat liver. As compared to oleic and 19:4n-5 acids, both ketone body production and triglyceride secretion were significantly lowered when arachidonic acid was perfused. The concentration of triglyceride in the post-perfused liver was lower upon perfusion with arachidonic acid than upon perfusion with oleic acid or 19:4n-5 acid. Cholesterol secretion in the liver perfused with arachidonic acid or 19:4n-5 acid was significantly higher than with oleic acid. The concentration of cholesterol in the post-perfused liver was slightly but significantly higher with 19:4n-5 acid than with the other fatty acids. The results suggest that 19:4n-5 acid when compared with arachidonic acid affects lipid metabolism in liver differently.

Animals↗
PubMed1991

[Study on fluctuation of several parameters in varicella].

Specific immunological responses (varicella-specific IgG and IgM) and various parameters (interferon, C3, C4, platelet count, erythrocyte count, erythrocyte CR1) in varicella infection were determined over the course of the disease (days) and their relationships to severity and immunological significance evaluated. Defining the day varicella appeared as disease day 0, IgG appeared on the disease day 4 and IgG on day 5. The preceding disease days were dominated by non-specific immunological mechanisms. Interferon appearance preceded that of these antibodies but did not correlate with severity. In serious cases, C3 and C4 increased in the acute stage while platelet count declined. Erythrocyte count decreased in severe cases after disease day 5. Three patients with lower erythrocyte CR1 activity values remained critical. These findings suggested that determining platelet count is expedient in determining severity in the early stage and that the complement pathway is a major component of early immunological response.

Adult↗
PubMed1991

In vitro infection of natural killer cells with different human immunodeficiency virus type 1 isolates.

Natural killer (NK) cells are a discrete subset of leukocytes, distinct from T and B lymphocytes. NK cells mediate spontaneous non-MHC-restricted killing of a wide variety of target cells without prior sensitization and appear to be involved in initial protection against certain viral infections. Depressed NK cell-mediated cytotoxicity, one of the many immunological defects observed in AIDS patients, may contribute to secondary virus infections. Here we report that clonal and purified polyclonal populations of NK cells, which expressed neither surface CD4 nor CD4 mRNA, were susceptible to infection with various isolates of human immunodeficiency virus type 1 (HIV-1). Viral replication was demonstrated by detection of p24 antigen intracellularly and in culture supernatants, by the presence of HIV DNA within infected cells, and by the ability of supernatants derived from HIV-infected NK cells to infect peripheral blood mononuclear cells or CD4+ cell lines. Infection of NK cells was not blocked by anti-CD4 or anti-Fc gamma RIII monoclonal antibodies. NK cells from HIV-infected and uninfected cultures were similar in their ability to lyse three different target cells. Considerable numbers of cells died in HIV-infected NK cell cultures. These results suggest that loss of NK cells in AIDS patients is a direct effect of HIV infection but that reduced NK cell function involves another mechanism. The possibility that NK cells serve as a potential reservoir for HIV-1 must be considered.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Differentiation of human embryonal carcinoma cells induces human immunodeficiency virus permissiveness which is stimulated by human cytomegalovirus coinfection.

Human immunodeficiency virus (HIV) replicates in differentiated but not undifferentiated NTERA-2 human embryonal carcinoma cells; neither cell type expresses CD4. Susceptibility of the differentiated cells is enhanced by coinfection with cytomegalovirus. HIV infection induces lactoseries glycolipids, suggesting a mechanism whereby HIV might interfere with normal embryogenesis.

Antibodies, Monoclonal↗
PubMed1991

[A study on auditory disturbances after microvascular decompression for hemifacial spasm].

After establishing an operation of microvascular decompression by Jannetta in 1975, an improvement rate of hemifacial spasm have increased. However, postoperative hearing deficits, equilibrium disturbances and facial paresis have been described in some publications. Fifty-seven of 119 patients with hemifacial spasm operated from 1982 to 1989, were examined by audiometry before and after operation. In patients with tinnitus at the time of facial spasm and closing eyelids, tinnitus improved almost in many cases. Of 57 patients, 8 (5 with sensorineural hearing loss, 3 with conductive hearing loss) had postoperative hearing impairments in operated ears, and 7 (7 with sensorineural hearing loss) had in the other ears, too. Of 7 patients having sensorineural hearing loss observed for several months, 4 having slight sensorineural hearing loss recovered at the same hearing level before operation. In 2 patients having profound sensorineural hearing loss, however, hearing improvement did not observed in each case.

Adult↗
PubMed1991

[Effects of verapamil on cyclosporine. A (CsA)-induced nephropathy in ischemic kidney model in rats: changes in systemic hemodynamics and hepatic and renal microsomal cytochrome P-450].

We have examined the effect of verapamil on CsA-induced nephropathy by measurement of systemic hemodynamics including each organ blood flow using the microsphere method in ischemic kidney model of hemi-nephrectomized Wistar rats. Hepatic and renal microsomal cytochrome P-450 contents and their enzyme activities were measured to study the correlation between CsA-induced nephropathy and induction of hepatic and renal microsomal cytochrome P-450. All rats were hemi-nephrectomized (l-nephrectomy) and were classified into the following 6 groups: 1) control groups, 2) CsA at a dose of 40 mg/kg per day orally for 7 days (CsA group), 3) Oral administration of verapamil for 7 days in the CsA group (CsA + V group), 4) 20 min clamping of the remaining right kidney pedicle (Ischemic, Is group), 5) CsA was administered in the Is group (Is + CsA group), 6) Addition of verapamil to CsA in the Is + CsA group (Is + CsA + V group). Verapamil was given in the drinking water and the average dose calculated from the amount of drinking was 4.7 +/- 1.0 mg/kg per day and 5.2 +/- 0.7 mg/kg per day for the CsA + V group and the Is + CsA + V group, respectively. CsA caused significant increases in BUN and serum creatinine (sCr) with a significant decreases in renal inulin clearance (CIn) in all groups. When compared with the Is group, CsA caused significant decreases in cardiac output and all organ blood flow especially in renal blood flow with significant increases in BUN and sCr in the Is + CsA group.2+ degree of nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Adoptive transfer of experimental autoimmune uveoretinitis induced by interphotoreceptor retinoid-binding protein.

The immunopathogenic mechanisms of experimental autoimmune uveoretinitis (EAU) induced by interphotoreceptor retinoid-binding protein (IRBP) were studied. Lymph node (LN) cells or spleen cells were collected from donor rats 14 days after the immunization with IRBP. After the 3-day pre-incubation of these cells with either IRBP or Concanavalin A (Con A), the cells were transferred to naive syngeneic rats intraperitoneally. EAU was successfully transferred by LN cells pre-cultured with IRBP, while EAU was poorly transferred by LN cells pre-cultured with Con A. On the other hand, spleen cells pre-cultured with either IRBP or Con A were quite potent to transfer EAU. In addition, the enriched helper/inducer T-cells repeatedly transferred EAU, while the enriched suppressor/cytotoxic T-cells did not. There also existed the simultaneous involvement of pinealitis. The histopathological features of EAU and pinealitis were generally similar to those in actively immunized rats. The immune responses to IRBP in recipients with EAU were mostly cellular (delayed hypersensitivity type skin response and proliferative responses of lymphocytes), while humoral responses (Arthus type skin response and antibody activities) were quite weak in most of the recipients. Thus, it was confirmed that cellular immunity plays a major role in the adoptive transfer of EAU by IRBP as in S-antigen-induced EAU.

Animals↗
PubMed1990

Parathyroid hormone causes a transient rise in intracellular ionized calcium in vascular smooth muscle cells.

The effect of parathyroid hormone on intracellular calcium concentration in vascular smooth muscle cells in culture was studied. Human PTH 1-34 (hPTH (1-34)) caused a transient rise in intracellular calcium in a dose-dependent manner at physiological concentrations. The effect of PTH was mimicked by dibutyryl cyclic AMP and inhibited by a PTH receptor antagonist. The effect of PTH was increased in parallel with extracellular calcium concentration and a sustained response was observed when extracellular calcium was 2 mM or higher. The PTH action was blocked by nisoldipin, a calcium antagonist, but not by ouabain, a Na, K-ATPase inhibitor. These data indicate that PTH increases intracellular calcium through its receptor via opening calcium channels. A possible role of this effect in the regulation of vascular tone is also discussed.

Animals↗
PubMed1990

Down syndrome: toward a molecular definition of the phenotype.

Down syndrome (DS) is a major cause of mental retardation and heart disease. Although it is usually caused by the presence of an extra chromosome 21, a subset of the diagnostic features may be caused by the presence of only band q22. Molecular and cytogenetic analysis of a family with 4 DS members has significantly narrowed the chromosomal region responsible for the DS phenotype: congenital heart disease, facial features, and possibly dermatoglyphics. Using high-resolution chromosome banding and in situ hybridization, we found the DS phenotype in the family is caused by a duplication of chromosome 21 material including a region of distal band q22.1 below the limit of cytogenetic resolution, in addition to bands q22.2-q22.3. By quantitative Southern blot analyses of DS members of the family, all random DNA sequences and expressed genes mapping in band q22.1 and proximal are found not to be duplicated. These include cDNA probes for the genes for superoxide dismutase (SOD1) mapping in 21q22.1 and for the amyloid precursor protein (APP) mapping in 21q21.05; D21S46 in 21q11.2-21.05; and D21S47 and SF57 in 21q22.1-q22.3. With one exception, DNA sequences mapping in band q22.3 are duplicated (D21S39, D21SD42, and D21S43). This analysis has now been extended to show that D21S17, previously mapped to band 21q22.3, is not duplicated. In conclusion, the genes SOD1 and APP have been excluded from a necessary role in generating the classical DS features, and the proximal border of the chromosomal region causing DS has been defined.

Base Sequence↗
PubMed1990

Use of colloidal silica (Sepracell-MN) for enrichment of dendritic cells from human peripheral blood: comparison with other methods.

Three methods are described for enrichment of dendritic cells from human peripheral blood. In method 1, mononuclear cells were incubated in plastic tissue culture flasks for two h. Nonadherent cells were removed. Adherent cells were washed to remove floating cells and incubated for 14 h at 37 degrees C in 5% CO2. Carbonyl iron was added, and the flasks were incubated for another 2 h. Nonadherent cells were subjected to centrifugation over metrizamide gradient. Phagocytic cells containing ingested carbonyl iron, small lymphocytes, and free carbonyl iron particles passed through the metrizamide, while the interface cell population was enriched for dendritic cells. The purity and yield of enriched dendritic cells were 52.8% and 0.05%, respectively. In method 2, adherent mononuclear cells were cultured overnight, and the released cells (released adherent cells) were centrifuged over metrizamide to separate low-density cells. Monocytes from this low-density cell population were removed by panning over human gamma globulin-coated plastic Petri dishes. In this method the average purity and yield of DC were 63.8% and 0.1%, respectively. In method 3, released adherent cells were treated with anti-CD5 and anti-CD14 monoclonal antibodies plus baby rabbit complement for 15 min, washed, and centrifuged with colloidal silica (Sepracell-MN). Centrifugation with Sepracell-MN was repeated three times. Low-density cells were panned twice over human gamma globulin-coated plastic Petri dishes. Nonadherent cells were highly enriched for DC. Contamination of T cells, B cells, and NK cells was undetectable by flow cytofluorometry. Contamination of monocytes was less than 2%. This method provided greater than 85.0% purity and 0.4% yield. This method (method 3) combines adherence, complement-dependent lysis, centrifugation with colloidal silica, and panning and provides the best yield and purity; it is therefore recommended for optimal purification of DC.

Antibodies↗
PubMed1990

Structural requirements for the binding of oligosaccharides to immobilized lectin of Erythrina variegata (Linn) var. orientalis.

The structural requirements for the interaction of asparagine-linked oligosaccharide moieties of glycoproteins with Erythrina variegata agglutinin (EVA) were investigated by means of affinity chromatography on an EVA-Sepharose column. Some of the branched poly-N-acetyllactosamine-type oligosaccharides obtained from human erythrocyte band 3 glycoprotein were found to show high affinity to EVA-Sepharose, whereas complex-type oligosaccharides were shown to have low affinity. Hybrid type, oligomannose-type and unbranched poly-N-acetyllactosamine-type oligosaccharides bound very little or not at all to EVA-Sepharose. To further study the carbohydrate-binding specificity of this lectin, we investigated the interaction of immobilized EVA and oligosaccharide fragments obtained through partial hydrolysis from branched poly-N-acetyllactosamine-type oligosaccharides. Branched poly-N-acetyllactosamine-type oligosaccharides were subjected to limited hydrolysis with 0.1% trifluoroacetic acid at 100 degrees C for 40 min and then separated on an amino-bonded silica column. One of pentasaccharides thus prepared strongly bound to the EVA-Sepharose column. Structural analysis of this pentasaccharide showed that the Gal beta 1-4GlcNAc beta 1-3(Gal beta 1-4GlcNAc beta 1-6)Gal sugar sequence, which is an I-antigen determinant, was essential for the high affinity binding of the oligosaccharides to the EVA-Sepharose column.

Amino Acid Sequence↗