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Biomedical subjects

N Yoshimura

Publications and source records attributed to N Yoshimura.

At least 559 records · Page 31Linked to original sources
PubMed1987

[Long-term follow-up study of renal autotransplantation in reno-vascular hypertension].

Therapeutic effects of heterotopic renal transplantation for renovascular hypertension were evaluated in ten patients with a follow-up period of more than three years. These ten patients consisted of 4 males and 6 females with the range of age from 21 to 55. The causes of renovascular hypertension were fibromuscular dysplasia in five patients, atherosclerosis in 3 and aortitis syndrome in 2. All the ten patients had a unilateral stenosis of the renal artery. At 3 years after operation, the blood pressure fell to normal range without any medication in 9 patients (90%) and it could be controlled with antihypertensive drugs in the remaining one patient. Operative mortality or deterioration of graft function was not experienced in any of them. One of the female patients had three deliveries after operation. The heterotopic renal autotransplantation is a therapeutic method to be selected for renovascular hypertension, since excellent and stable long-term results can be achieved.

Adult↗
PubMed1987

[Light and electron microscopic observations of cysts in the brain from an autopsy case of cryptococcus meningitis].

We gave some considerations to the significance of cyst formation in a case of cryptococcus meningitis by examining the cysts themselves and comparing the organisms in the cysts with those disseminated throughout the subarachnoid space by light and electron microscopy. An 18-year-old girl had complained of headache, stiffneck and fever at the onset. These symptoms worsened into confusion without any definite diagnosis, then resulted in an arrest of spontaneous respiration which led to use of respirator for 12 days. The patient died 40 days after the onset. The brain weighed 1440 g and showed moderate swelling with opacity of the leptomeninges, which was very evident over the convexity and around the basal side of the pons. Subarachnoid fresh hemorrhage was also observed around the basal side of the brain stem. Microscopic examination of the subarachnoid space revealed widely disseminated Cryptococcus neoformans varied in size, whose cell wall showed a positive staining reaction to PAS. The organisms had characteristic spicules positively stained with cresyl violet radiating out of the cell body, and were associated with infiltration of lymphocytes, macrophages and polymorphonuclear leukocytes throughout the subarachnoid space. Some portions of arachnoid membrane, dura mater and vessel walls in the subarachnoid space especially the adventitia of the basilar artery were replaced by multiple cysts. The cysts were tightly filled with large numbers of small uniformly sized organisms which often showed budding. These cysts showed no histological evidence for inflammation. Further studies to demonstrate those differences were carried out with electron microscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Phorbol ester: effect on intraocular pressure, adenylate cyclase, and protein kinase in the rabbit eye.

Protein kinase C was identified as a major protein kinase enzyme activity in rabbit ciliary processes. Phorbol myristate acetate (4 beta-PMA) in the presence of Ca2+ activated protein kinase C but did not directly affect the cyclic AMP-dependent protein kinase enzyme isolated from ciliary processes. To elucidate possible roles of protein kinase C, PMA was injected intravitreally into rabbit eyes. Fifty pmoles of PMA produced approximately a 40% decrease of the intraocular pressure relative to the control eye lasting for more than 72 hr. A reduction of intraocular pressure was still elicited by this dose of PMA in animals pretreated with systemic indomethacin given to suppress a possible inflammatory response. The biologically inactive analogue, 4 alpha-phorbol didecanoate (100 pmoles/eye) had no significant effect on intraocular pressure. In vivo and in vitro treatment with PMA had no significant effect on adenylate cyclase in ciliary process membranes assayed in vitro. However, protein kinase C isolated from rat brain, when added together with cofactors to membranes in vitro, augmented adenylate cyclase activation by isoproterenol, vasoactive intestinal peptide and aluminum fluoride. A slight increase in the basal activity and in the forskolin response was not statistically significant. The effect of protein kinase C to increase responsiveness of ciliary process adenylate cyclase was totally dependent on the presence of Ca2+ and was augmented by addition of PMA. These findings indicate modulation of adenylate cyclase activity by protein kinase C acting at the level of the G-proteins and suggest a possible role for this enzyme in water and electrolyte transport in the ciliary processes.

Adenylyl Cyclases↗
PubMed1986

Immunologic and molecular characterizations of T cell-derived T cell activating factor.

Culture supernatants from several subclones of a human T hybrid line (24A) stimulated with PMA showed co-stimulatory activity in the proliferation of Con A-stimulated murine thymocytes, but did not show any IL 2 activity. Some subclones did not show co-stimulatory activity even when stimulated with PMA, excluding the possibility of a carry-over effect. The factor found in the culture supernatants increased IL 2 production in normal T cells stimulated with a suboptimal concentration of PHA. The factor also induced IL 2 production in a T hybrid clone, T-394.1, when the latter was stimulated with a suboptimal concentration of mitogens, indicating a direct effect by this T cell-derived factor on mitogen-stimulated T cells inducing IL 2 production. This factor also induced the generation of other lymphokines such as BCDF and IFN-gamma. Northern blot analysis showed that the factor induced an increase in mRNA for IL 2 as well as IL 2 receptor. These results indicated that T cells could secrete a factor with IL 1-like activity. However, Northern blot analysis showed that mRNA from a T hybrid clone does not cross-react with cDNA for IL 1 (beta) derived from human monocytes.

Animals↗
PubMed1986

Immunogold electron-microscopic localisation of calpain I in skeletal muscle of rats.

By using a double-affinity-purified first antibody and colloidal gold-conjugated second antibody, it is shown that calpain I (a cysteine proteinase activated by micromolar concentrations of Ca2+) has a predominant intracellular location in the I-band region of the extensor digitorum longus (EDL) muscle of the rat, but is not exclusively associated with the Z-line.

Animals↗
PubMed1986

The requirement for the renal transplant to induce allograft unresponsiveness by the combination of extracted histocompatibility antigen and cyclosporine.

The impact of the presence of the allograft on the induction of unresponsiveness by the immunosuppressive combination of cyclosporine (CsA) and 3M KCl-extracted histocompatibility Antigen (Ag) was assessed by comparing the outcome of renal transplants when the regimen was used pretransplantation versus peri- and posttransplantation. WFu rat hosts, which had been pretreated with either one (-11, -10, -9) or three (-25, -24, -23, -18, -17, -16, -11, -10, -9) cycles of CsA and BUF Ag (-11 or -25, -18, -11) prior to implantation of BUF renal allografts, failed to display the prolonged graft survival achieved with this regimen administered in the peri- (-1, 0, +1) and immediate posttransplant (+7, 8, 9, 14, 15, 16) period. However, OX-8 positive, putative T-suppressor (Ts) cells in the spleens of pretreated hosts were able to transfer slightly prolonged BUF allograft survival to virgin, secondary syngeneic hosts. The OX-8-positive cells induced by pretreatment were apparently inhibited from prolonging BUF allografts in primary hosts by cellular elements vulnerable to splenectomy, total-body irradiation, or a three-day peritransplant course of CsA therapy. Therefore the presence of the renal graft at the time of peri and immediate posttransplant administration of Ag-CsA facilitates the induction of unresponsiveness, possibly due to continued release of histocompatibility antigen to stimulate, and/or to providing an important peripheral environment promoting differentiation and maturation of, Ts cells.

Animals↗
PubMed1986

Biochemical demonstration and immunohistochemical localization of calpain in human skin.

The biochemical properties and immunohistochemical localization of calpain, a Ca++-dependent, intracellular, nonlysosomal cysteine proteinase was examined in human skin. Human epidermal calpain I was fractionated on a DEAE-cellulose column and was found to be half-maximally activated at 3.5 microM free Ca++ and fully activated at 10 microM Ca++ as measured by casein hydrolysis. Immunoelectrophoretic blotting of calpain revealed only a single band of Mr 83,000, when the blot was made with affinity-purified anti-calpain I heavy subunit IgG. Immunohistochemical staining of normal human epidermis showed that calpain I was localized in the cytoplasm of keratinocytes in the mid to upper epidermis but not in the basal cells. In untreated psoriatic epidermis, the deposition of this proteinase was visualized weakly just beneath the stratum corneum. However, remarkable staining was observed after photochemotherapy of topical psoralen plus long-wave UV irradiation. Whether the photochemotherapy induced a quantitative increase in the amount of calpain or merely made calpain more stainable by altering the membrane remains unknown.

Antibody Specificity↗
PubMed1986

Metabolism of glycoproteins in cultured retinal pigment epithelium.

The turnover and migration of synthesized glycoproteins in the cultured retinal pigment epithelium have been studied. Quantitative study indicated that half-time of 3H-fucosylglycoproteins was 11.6 days. Autoradiography was performed several times after incubation of 3H-fucose. Retinal pigment epithelium constantly synthesized glycoproteins and released them into the basal extracellular material. Possible functions of the glycoproteins are discussed.

Animals↗
PubMed1986

Growth factors induce actin disruption in cultured human retinal pigment epithelial cells.

Exposure of cultured human retinal pigment epithelial cells to platelet-derived growth factor, nerve growth factor or epidermal growth factor resulted in a time- and dose-dependent alteration in the distribution of actin stained by rhodamine-phalloidin. These growth factors (platelet-derived growth factor of 80 ng/ml, nerve growth factor of 10 ng/ml or epidermal growth factor of 10 ng/ml) caused disappearance of actin filaments from the peripheral region of a cell in 1 or 2 h and change of cell configuration to spindle shape in 3 or 4 h. Other growth factors, fibroblast growth factor of 10 ng/ml and insulin of 25 mumol/ml had no effect on actin distribution. The alteration of actin and the change of cellular shape might be associated with stimulation of cell growth and migration of retinal pigment epithelial cells.

Actins↗
PubMed1986

Rapid proteolysis of brain MAP-1 related cytoskeleton-associated 350kd protein by purified calpain.

Microtubule associated protein-1 of brain and its intracellular 350kd analogues were highly sensitive to purified Ca2+-dependent cysteine proteinase (calpain). After 15 second digestion, we detected intermediate degradation products of MAP-1 by immunoblotting using anti-MAP-1 antibody as 290, 260, 220, 170, 140, 112, 80, 68, and 32kd polypeptides. These values corresponded to the molecular weights of the immunoreactive polypeptides of microtubule-enriched cytoskeletons isolated from HeLa and SV-3Y1 cells, suggesting the action of endogenous calpain on intracellular MAP-1 analogues in vivo or during the course of preparation.

Animals↗