Biomedical subjects

H Ishida

Publications and source records attributed to H Ishida.

At least 397 records · Page 22Linked to original sources

PubMed1997

Nisoldipine blocks the increase of intracellular free calcium-ion concentration associated with elevated sodium-lithium countertransport activity in erythrocytes in patients with NIDDM.

To understand the mechanism by which elevated sodium-lithium countertransport activity (SLC) associates with increased intracellular free calcium-ion concentration ([Ca2+]i), we investigated the relationship between SLC and the effects of the extracellular Ca2+ concentration ([Ca2+]o) and a Ca2(+)-channel blocker, nisoldipine, on [Ca2+]i in erythrocytes from 48 patients with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM). There was a significant correlation between SLC and [Ca2+]i. Nisoldipine in the incubation medium significantly decreased [Ca2+]i, and there was a significant positive correlation between SLC and the degree of [Ca2+]i decrease. When the [Ca2+]o was elevated, [Ca2+]i was significantly increased, but nisoldipine almost completely suppressed this increase of [Ca2+]i. There was a significant positive correlation between SLC and the degree of the suppression. These data suggest that elevated SLC correlates with increased [Ca2+]i, and that the increased [Ca2i]i might be due to the increased Ca2+ influx through a dihydropyridine-sensitive Ca2+ pathway.

Adult↗

PubMed1997

Insulin secretion and its modulation by antiarrhythmic and sulfonylurea drugs.

Cardiovascular drugs such as antiarrhythmic agents with Vaughan Williams class Ia action have been found to induce a sporadic hypoglycemia. Recent investigation has revealed that these drugs induce insulin secretion from pancreatic beta-cells by inhibiting ATP-sensitive K+ (KATP) channels in a manner similar to sulfonylurea drugs. The mechanism underlying block of KATP channels by antiarrhythmic drugs was different, however, from that of sulfonylureas: firstly, because binding of radioactive glibenclamide could not be inhibited by unlabelled antiarrhythmic agents, and vice versa; secondly, because the two compounds differ in the kinetics and sidedness of drug action-antiarrhythmic drugs act on the channel from the inner surface of the cell membrane, whereas glibenclamide binds through the intramembrane pathway; finally, it was shown that functional KATP channels in beta-cells are composed of two distinct molecules-a sulfonylurea receptor (SUR) and a channel pore-forming subunit, an inwardly-rectifying K channel with two transmembrane regions (Kir6.2). Antiarrhythmic drugs reversibly inhibit the K+ conductance displayed by the Kir6.1 (a putative KATP channel clone)-transfected NIH3T3 cells. Therefore they appear to interact directly with the pore-forming subunit, thereby inhibiting KATP channel currents and exerting an insulinotrophic effect.

3T3 Cells↗

PubMed1997

Effect of azelastine on PGE2 production in fibroblasts in normal skin. The possibility of inhibition of inducible cyclooxygenase by azelastine.

The effects of azelastine on prostaglandin E2 (PGE2) production were investigated by using cultured normal dermal fibroblasts obtained from the same traumatic region of 3 patients and the CRL-1475 cell line. Interleukin-1beta (IL-1) enhanced PGE2 production in cultured normal fibroblasts and CRL-1475 cells. 10(-6) M azelastine inhibited PGE2 production in these IL-1-stimulated fibroblasts. However, the drug did not influence spontaneous PGE2 production in cultured CRL-1475 fibroblasts not stimulated with IL-1 but slightly it increased in cultured normal dermal fibroblasts under the same conditions. These results suggest that azelastine either regulates synthesis of an inducible cyclooxygenose protein or inhibits PGE2 production as an inducible cyclooxygenase inhibitor.

Accidents↗

PubMed1997

Molecular cloning of a novel member of semaphorin family genes, semaphorin Z.

Semaphorins/collapsins (semaphorins) comprise a large family of proteins implicated in axonal guidance during development. We cloned a novel member (semaZ) of the semaphorin gene family from a rat brain cDNA library. Sema Z was thought to be an integral membrane glycoprotein of 887 amino acids including a sema domain composed of 532 amino acids. The amino acid sequence of Sema Z showed 28-35% identity with other semaphorins in its sema domain, including 15 conserved cysteine residues. The cytoplasmic domain of Sema Z was found to be rich in prolines. Our phylogenetic analysis based on the amino acid sequence of the sema domains and the location of conserved N-glycosylation sites suggested that the sema domain of Sema Z belongs to a new class, class VI. We detected the semaZ mRNA in the first branchial arch of embryonic day 11 (E11) rat embryo, and subsequently in the myotomes and the dorsal root ganglia in developing somites from E11.5 through E13.5, but not in the brain. However, at E15, 18, 21 and P0, semaZ was highly expressed in the brain. Sema Z might play a role in both peripheral and central nervous system development.

Amino Acid Sequence↗

PubMed1997

Clinical evidence of peroxynitrite formation in chronic renal failure patients with septic shock.

The production of both nitric oxide (NO) and superoxide increases in septic shock. The cogeneration of these molecules is known to yield peroxynitrite, which preferentially nitrates tyrosine residues of protein and non-protein origins. We present evidence of peroxynitrite production in septic shock by measuring plasma nitrotyrosine. The nitrotyrosine was measured by an HPLC C-18 reverse-phase column and ultraviolet detector in chronic renal failure patients with or without septic shock, and in healthy volunteers. Plasma nitrite + nitrate (NOx) was also measured to evaluate NO production. Nitrotyrosine was selected as an index for production of peroxynitrite because the direct measurement of peroxynitrite in vivo is difficult. Patients with renal failure were selected in order to minimize nitrotyrosine excretion through the kidney. Plasma nitrotyrosine levels were not detectable in volunteers, 28.0 +/- 12.3 microM (1.6 +/- 1.1% of total tyrosine) in renal failure patients without septic shock, and 118.2 +/- 22.0 microM (5.5 +/- 1.2% of total tyrosine) in patients with septic shock. NOx levels were also higher in patients with septic shock than in patients without septic shock (173.9 +/- 104.7 vs. 75.6 +/- 19.1 microM). Although renal failure itself increases plasma concentrations of both molecules, the higher levels in patients with septic shock suggest that peroxynitrite is generated and the nitration of tyrosine residues is increased in this disease.

Adult↗

PubMed1997

The large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is fragmented into 37-kDa and 16-kDa polypeptides by active oxygen in the lysates of chloroplasts from primary leaves of wheat.

Lysates of chloroplasts isolated from wheat (Triticum aestivum L. cv. Aoba) leaves were incubated on ice (pH 5.7) for 0 to 60 min in light (15 mumol quanta m-2 s-1), and degradation of the large subunit (LSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco: EC 4.1.1.39) was analyzed by applying immunoblotting with site-specific antibodies against the N-terminal, internal, and C-terminal amino acid sequences of the LSU of wheat Rubisco. The most dominant product of the breakdown of the LSU and that which was first to appear was an apparent molecular mass of 37-kDa fragment containing the N-terminal region of the LSU. A 16-kDa fragment containing the C-terminal region of the LSU was concomitantly seen. This fragmentation of the LSU was inhibited in the presence of EDTA or 1,10-phenanthroline. The addition of active oxygen scavengers, catalase (for H2O2) and n-propyl gallate (for hydroxyl radical) to the lysates also inhibited the fragmentation. When the purified Rubisco from wheat leaves was exposed to a hydroxyl radical-generating system comprising H2O2, FeSO4 and ascorbic acid, the LSU was degraded in the same manner as observed in the chloroplast lysates. The results suggest that the large subunit of Rubisco was directly degraded to the 37-kDa fragment containing the N-terminal region and the 16-kDa fragment containing the C-terminal region of the LSU by active oxygen, probably the hydroxyl radical, generated in the lysates of chloroplasts.

Animals↗

PubMed1997

Favorable donor site for epidermal cultivation for the treatment of burn scars with autologous cultured epithelium.

It is very important to determine from where we select the donor skin for epidermal cultivation in the treatment of burn scar disfigurement. To prove this point, we compared the appearance and histology of grafted sites according to the different donor sites. Thirty-eight patients with skin color difference and irregular contours of matured burn scars were superficially abraded and underwent autologous cultured epithelial grafting. These patients were followed more than 2 years. The donor skin for epidermal cultivations was taken from the buttock (group 1, 8 patients), sole (group 2, 6 patients), and adjacent to the site of the scar (group 3, 24 patients). In group 3, skin elasticity was also measured after 2 years. Hypo- and hyperpigmentation were well treated with autologous cultured epithelial grafting. The most favorable results in terms of color match were obtained in group 3, where the skin color resembled surrounding normal skin. The skin tension returned to almost normal. In group 2, the histology of the grafted site resembled the sole epidermis. It was concluded that the general principle of conventional skin grafting (i.e., "closer is best") was also correct in cultured epithelial grafting. Furthermore, it was revealed that cultured epithelium has a site specificity even after grafting.

Adolescent↗

PubMed1997

Treatment of giant congenital nevi with cryopreserved allogeneic skin and fresh autologous cultured epithelium.

Giant congenital nevi, confluent over 10% to 52% of the body surface area, were treated in 5 pediatric patients with allogeneic skin and autologous cultured epithelium (ACE). The lesions were excised to the adipose tissue and the wound was covered with cryopreserved or fresh allografted skin. Later, the skin surface was abraded and ACE was applied. The size of the cultured graft ranged from 360 to 900 cm2 (average, 630 cm2). In 3 patients the wounds healed well. Allograft cryopreservation averaged 50 days. The average interval to ACE application after skin grafting was 10 days. Histological rejection was minimal. In 2 patients the cultured grafts did not take. The wounds were covered with split-thickness skin grafts. In one such patient, a fresh allograft was used. In the other, ACE was applied 27 days after skin grafting. Vigorous rejection reaction was observed. Cryopreservation of allogeneic skin may be important in the treatment of human leukocyte antigen-mismatch patients with giant nevi, and ACE should be applied within 10 days of skin grafting.

Cells, Cultured↗

PubMed1997

Physiological roles of endothelium-derived nitric oxide in the epigastric island flaps of rabbits.

Nitric oxide (NO), identified as the mediator of endothelium-dependent relaxation of vascular smooth muscle, is known to cause a number of inflammatory conditions, especially in ischemia/reperfusion injury. This experimental study, using a rabbit epigastric island flap, was designed to investigate whether skin flap ischemia followed by reperfusion-influenced serum NO and c-GMP concentrations in the flap. In addition, we also investigated the premedicated effects of the NO synthase inhibitor and heparin on serum NO and c-GMP concentrations in skin flap ischemia/reperfusion. Serum NO concentration after 15, 30, 45, and 60 minutes of ischemia followed by reperfusion significantly increased compared with that in nonischemic control and elevated flaps. On the contrary, serum NO concentration was suppressed in L-NAME or aminoguanidine pretreated animals with ischemic group. Administration of heparin increased the serum NO concentration in elevated flaps, but suppressed it in ischemic flaps followed by reperfusion. The changes in serum c-GMP and NO concentrations were related in all of the experimental groups. These results suggest that NO may be derived from vascular endothelial cells and dilate peripheral vessels in compensation for ischemia.

Animals↗

PubMed1997

Synovial mononuclear cells consist with T cells which produce high levels of tumor necrosis factor alpha.

To determine whether synovial mononuclear cells include a population of tumor necrosis factor alpha-producing T cells, we measured tumor necrosis alpha levels in culture supernatants of synovial mononuclear cells by ELISA and analyzed tumor necrosis alpha mRNA-positive cell frequencies. There were no significant differences in the spontaneous levels of TNF alpha between synovial mononuclear cells and peripheral mononuclear cells. The frequency of tumor necrosis factor alpha mRNA-positive cells in synovial mononuclear cells was higher than that of peripheral mononuclear cells. When stimulated with a superantigen, mononuclear cells from the synovial fluid of rheumatoid arthritis patients showed higher levels of tumor necrosis factor alpha production (1,035 +/- 817 pg/ml) than did mononuclear cells from their peripheral blood (236 +/- 180 pg/ml). In addition, we observed that a few T cell clones were resistant to superantigenic restimulation in vitro. We conclude that when these types of T cells persist in the synovium, they play a role in the development of rheumatoid arthritis via a mechanism involving tumor necrosis factor alpha production.

Animals↗

PubMed1997

Clinicopathologic study of nasal T/NK-cell lymphoma among the Japanese.

A high prevalence of nasal lymphoma expressing a T- or natural killer (NK)-cell phenotype (NTCL) with frequent association of Epstein-Barr virus (EBV) has been indicated in Asians. To characterize NTCL among the Japanese, the clinicopathologic features of 32 cases were evaluated and the cases were also analyzed for EBV-RNA using an ISH method. Morphologically, 31 cases were identified by atypical pleomorphic lymphoid infiltrates with polymorphous, angicentric, and necrotic features. Their lymphoma cells ranged in size from small to large and were mixed in varying proportion from case to case. The other one case showed a monomorphic 'blastic' appearance. EBV-encoded small RNA (EBER) was detected in the neoplastic cells of 27 of the 32 cases examined. In the five EBV-negative cases, one was the 'blastic' type. Clonal T-cell receptor gene rearrangement was detected in none of seven cases examined. The patients had a median follow-up of 9 months (range, 1 month to 14 years and 11 months). The Kaplan-Meier estimate of overall survival was 49% at 5 years, correlating with clinical stage. These data support the concept that most cases of NTCL are identified as tumors with T/NK-cell characteristics and EBV association, distinctly different from other peripheral T-cell lymphomas. Furthermore, the one case of an EBV-negative 'blastic' variant appears not to fit well into the pleomorphic category but more closely resembles the pathologic features of extranasal angiocentric lymphoma with lymphoblastoid appearance. This study also showed no clear difference in clinical aspects other than the original site or in prognosis, between NTCL and extranasal angiocentric lymphomas despite the higher incidence of EBV association and the tendency for that peculiar anatomical site to be restricted to the former group.

Adolescent↗

PubMed1997

Significance of prostate-specific antigen after radical prostatectomy.

BACKGROUND: Serum prostate-specific antigen (PSA) is expected to be undetectable after radical prostatectomy unless there is residual disease or disease progression. The aim of this study was to confirm the usefulness of serum PSA measurements in monitoring patients after radical prostatectomy. METHODS: We conducted a study of 50 patients who underwent radical prostatectomy for clinical stage T1-2 or small T3 prostate cancer, analyzed serum PSA levels before and after surgery and compared the pathological findings and clinical outcome. RESULTS: Postoperative PSA elevation (PSA failure) was noted in 13% of patients with organ-confined disease (OCD), 43% with positive surgical margins and/or seminal vesicle involvement (PSM/SVI), and 60% with positive lymph nodes (N+). Postoperative clinical failure was noted in 8 patients, and all were preceded by PSA failures. The 3-year PSA failure-free rates were 86.5%, 32.1%, and 40.7% and the 3-year clinical failure-free rates were 100%, 67.5%, and 73.5% in patients with OCD, PSM/SVI and N+, respectively. CONCLUSION: An elevation of serum PSA levels after radical prostatectomy was a sensitive indicator of persistent disease after surgery, and preceded clinical manifestations of disease progression.

Aged↗

PubMed1997

Identification of calprotectin, a calcium binding leukocyte protein, in human dental calculus matrix.

Calprotectin is a calcium binding protein produced by leukocytes, macrophages and epithelial cells, and its levels in several tissues increase during infections and in many inflamed areas, suggesting that it may be an indicator of inflammatory activity. Osteopontin is a prominent phosphorylated glycoprotein in bone matrix, having calcium binding capacity. Recently, it has been reported that calprotectin and osteopontin are present in urinary stones (pathological mineralized masses in the body), and that these proteins may be involved in their formation. Dental calculus formed by mineralization of dental plaque is an inflammatory factor which may contribute to periodontal disease. It contains many organic components involved in mineralization. We recently found osteopontin molecules in human dental calculus and suggested that the components of its matrix may be similar to those of urinary stones. In this study, we investigated the presence of calprotectin in human dental calculus by immunohistochemical and immunoblotting analyses using a specific antibody for calprotectin. After fixation and demineralization of dental calculi adhered to tooth roots, sections embedded in paraffin were immunoreacted with the antibody for calprotectin and positive immunostaining for calprotectin was observed. Dental calculus proteins were then extracted with EDTA and separated by electrophoresis on 15% polyacrylamide gels. By immunoblotting analysis, 3 or 4 bands were observed at 11, 14.5, 22-25, 28 or 36.5 kDa and these patterns corresponded to those of calprotectin subunits. When non-immune rabbit serum was used instead of calprotectin-specific antibody as a negative control, no immunoreactivity was observed. These findings indicate that calprotectin is associated not only with antibacterial action but also with calcium binding capacity during dental calculus formation.

Calcium-Binding Proteins↗

PubMed1997

Foot structure and foot protein in the cross striated muscle of a pecten.

The foot-like structure of pecten (mollusk) cross striated muscle cells was studied from structural and biochemical standpoints, and compared with foot structures of vertebrate skeletal muscle cells. In vertebrate muscles, foot structures have been observed at the interspace between T-tubules and sarcoplasmic reticula (SR). In pecten muscles, T-tubules were not observed, but SR were found situated in the outer portions of the cell contacting the cell membrane, and foot-like structures were recognized at the interspace between the SR and cell membrane. We could isolate the SR fraction from these muscles in which vesicles of SR/cell membranes were included. In the SR fraction, foot-like structures were observed ultrastructurally by thin sectioning. The size and shape of the foot-like structure, whether observed in intact cells or SR fractions, appear smaller than foot structures of vertebrates. However, when calculated by SDS-PAGE, the molecular weight of the structure is similar to that of vertebrates. These findings are discussed and compared to characteristics of foot structures and foot proteins of vertebrate skeletal muscles reported in previous studies.

Animals↗

PubMed1997

Docosahexanoic acid (DHA) improved glucose and lipid metabolism in KK-Ay mice with genetic non-insulin-dependent diabetes mellitus (NIDDM).

The hypoglycemic and hypolipidemic effect of docosahexaenoic acid (DHA; C22: 6omega-3) ethyl ester was examined in KK-Ay mice and neonatal streptozotocin-induced diabetic (NSZ) which are respectively obese and lean animal models of non-insulin-dependent diabetes mellitus (NIDDM), and in ddY normal mice. Single administration of DHA (500 mg/kg body weight) to KK-Ay mice significantly reduced (p<0.05) the blood glucose levels (BG) (p<0.05) and plasma free fatty acid levels (FFA) (p<0.05) at 10 h after oral administration when compared with control group. DHA (500 mg/kg body weight)-treated NSZ and normal mice, however, showed no change in these parameters. In addition, repeated administration of DHA (100 mg/kg) to KK-Ay mice significantly suppressed the increment of BG (p<0.05) and plasma triglyceride levels (TG) (p<0.01), and significantly decreased FFA (p<0.05) at 30 d compared with control group. DHA also significantly decreased the blood glucose at 60 and 120 min on insulin tolerance test (ITT). From these findings, it seems likely that DHA exhibits its hypoglycemic effects by increasing insulin sensitivity. It is concluded that DHA would be useful for treatment of obese type NIDDM with insulin resistance.

Animals↗

PubMed1997

[Carotid intima-media thickness and the occurrence of plaque in centenarians--data from the Tokyo Centenarian Study].

We studied carotid intima-media thickness at non-plaque sites and the occurrence of plaque in 25 centenarians (8 men and 17 women) living in Tokyo. The studies were done by B-mode ultrasonography and the results were compared with those found in 126 healthy subjects (83 men and 43 women) aged 28 to 82 years. The intima-media complexes were diffusely thickened in the centenarians; average thickness at bifurcations and at three sites in each common carotid artery ranged from 0.91 to 1.12 mm. The thickness was not associated with blood pressure or with serum lipid concentration. The thickness in the control group correlated with age, and that relationship fit a second degree equation. The expected values of mean intima-media thickness of the common carotid arteries at age 100 were computed with these equations; the predicted values ranged from 0.92 to 0.98 mm, which are close to the mean values measured in the centenarians (0.95 to 1.05 mm). However, the variations in intima-media thickness were greater in the centenarians. The prevalence of plaque in the centenarians was 40% for the right carotid artery and 36% for the left, but the prevalence among those in the eighth decade of life was 9.5% for both sides; plaque was not found among subjects in the sixth decade of life or younger. These data suggest that the degree of carotid arteriosclerosis is one factor that limits human longevity.

Adult↗

PubMed1997

[Lipid and lipoprotein profile of Japanese centenarians--high prevalence of hypo beta lipoproteinemia].

To study the relationship between lipids and longevity, we examined the level of serum lipids and apolipoproteins, and the susceptibility of low density lipoprotein (LDL) to oxidation of 45 centenarians (15 men, 30 women, mean age 101.1 +/- 1.4) living in the Tokyo metropolitan area. The average levels of total cholesterol (TC), of LDL-C of high-density lipoprotein cholesterol (HDL-C), and of apolipoproteins A1 and B were significantly lower in centenarians than in healthy middle-aged controls. The frequency of hypobeta-lipoproteinemia (apoB < 60 mg/dl) in centenarians was almost ten times as high as in controls. The time course of copper-mediated LDL, oxidation (assessed by monitoring 234 nm diene absorption (lag time)) did not significantly differ between the two groups. Analysis of LDL subfractions by non-denaturated gradient-gel electrophoresis showed a predominance of large, buoyant LDL particles (pattern A) in 75%, and a predominance of small dense LDL particles (pattern B) in 25% of centenarians. We also assessed activities of daily living (ADL) and cognitive function in the centenarians. Centenarians were divided into two groups according to the median ADL score, and were classified into five groups with a scale clinical dementia. In subjects with good ADL scores, the mean concentration of HDL-3-C was significantly higher than in those with poor ADL scores. Average levels of HDL-C were also significantly lower in subjects with moderate or severe dementia than in those with normal cognitive function. These findings suggest that centenarians have protective phenotypes of lipids and lipoproteins that protect them from atheroscierosis.

Activities of Daily Living↗

PubMed1997

[Tokyo Centenarian Study. 4. Apolipoprotein E phenotype in Japanese centenarians living in the Tokyo Metropolitan area].

To examine the relationship between apolipoprotein E (apoE) phenotype and life span, we measured the frequently of the apoE phenotype and allele in 54 Japanese centenarians who lived in the Tokyo metropolitan area in 1994, 1995, and 1996. The control group consisted of 973 subjects, 883 healthy volunteers who were described previously and 90 healthy people who came to the Keio health consulting center. The apoE phenotypes in the centenarians was 2 E2/E2 (3.7%), 5 E2/E3 (9.3%), 38 E3/E3 (70.4%), and 9 3E/E4 (16.7%). No other phenotype was observed. In the control group, the phenotypes were 2 E2/E2 (0.2%), 57 E2/E3 (5.9%) 712 E3/E3 (73.2%), and 179 E3/E4 (18.4%). The frequency of E2 was higher in the centenarians. The frequencies of the apoE allele in the centenarians and the control subjects were epsilon 2 8.3% vs. 3.5%, epsilon 3 83.3% vs. 85.4%, and epsilon 4 8.3% vs. 10.9%. The frequency of the apoE allele differed significantly between centenarians and control subjects (chi 2 = 6.84, p = 0.033). Levels of serum cholesterol and apolipoprotein B were significantly lower in the E2/E2 + E2/E3 centenarians. Studies of the frequency of the apoE allele in Japanese, French, and Finnish subjects showed that epsilon 2 is more frequent and epsilon 4 is less frequent in centenarians. These data show the apoE phenotype may affect life span: epsilon 2 is positively and epsilon 4 is negatively associated with longevity.

Aged↗