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Biomedical subjects

M Kondo

Publications and source records attributed to M Kondo.

At least 829 records · Page 46Linked to original sources
PubMed1991

[In vitro effect of chlorpromazine on the mineralization of tooth germ in mice--comparison with that of retinoic acid and HEBP].

Effects of chlorpromazine on the mineralization and alkaline phosphatase activity (ALP) in the tooth germ were examined and compared with those of retinoic acid and HEBP (1-hydroxyethylidene-1, 1-bisphosphonate). Mandibular first molars from 17-day-old mouse embryos were cultured with or without drugs. Calcium content and ALP in the tooth germ increased gradually from 0 to 7 days in culture, the increase of calcium being preceded by that of ALP. Retinoic acid suppressed increases of calcium and ALP in the tooth germ but not in the specimens precultured for 2 days, suggesting that retinoic acid inhibits the mineralization at an early developmental stage of the tooth. HEBP, a physiochemical inhibitor of mineralization, suppressed the increase of calcium, but significantly enhanced the increased of ALP in the tooth germ. Chlorpromazine, which has an antagonistic action towards calmodulin, also suppressed the increases of calcium and ALP in the tooth germ. Calmodulin antagonists W-7 and W-5 similarly suppressed the increases of calcium and ALP; W-5 had less effects on both calcium and ALP. These results indicate that calmodulin may be involved in the regulation of the mineralization in the tooth germ. These drugs are shown to possess different modes of inhibitory action on the mineralization.

Alkaline Phosphatase↗
PubMed1991

Anti-obesity and anti-diabetic actions of a beta 3-adrenoceptor agonist, BRL 26830A, in yellow KK mice.

The anti-obesity and anti-diabetic actions of BRL 26830A, beta 3-adrenoceptor agonist, (2 mg/kg administered intramuscularly daily for 2 weeks) were evaluated in obese diabetic Yellow KK mice and C57B1 control mice. The following parameters were compared in the treated vs. control animals: brown adipose tissue (BAT) thermogenesis, resting metabolic rate (RMR), insulin receptors in adipocytes, and blood glucose and serum insulin levels during a glucose overloading test. BRL 26830A significantly increased BAT thermogenesis and RMR but it decreased the amount of white adipose tissue without affecting food intake. Those actions contributed to the mitigation of obesity in Yellow KK mice. BRL 26830A also increased the concentration of insulin receptors and decreased the levels of serum insulin and blood glucose during the glucose overloading test in Yellow KK mice. In the glucose overloading test performed one hour after BRL 26830A injection, insulin secretion was significantly increased and the blood glucose level was markedly decreased in both groups. These observations suggest that BRL 26830A possesses anti-obesity and anti-diabetic actions and consequently may be useful for treating obesity as well as non-insulin-dependent diabetes mellitus with obesity.

Adipose Tissue, Brown↗
PubMed1991

Effect of media conditioned by concanavalin A activated spleen cells on pancreatic islet cells.

The effect of media conditioned by concanavalin A-activated spleen cells (C-sup) on insulin release and its islet cell cytotoxicity were studied. In a functional study, C-sup significantly inhibited both basal insulin release and glucose-stimulated insulin release. Morphologically, C-sup had a destructive effect on isolated islets after 72 h incubation. Islet cell cytotoxicity was shown by lactate dehydrogenase (LDH) release assay after 5 days incubation with C-sup in a dose-dependent manner. These results suggest that acceleration of the onset of diabetes in young diabetes prone (DP) Bio-Breeding/Worcester (BB/W) rats following the injection of C-sup may depend on the suppressive and cytotoxic effects of C-sup on pancreatic islet cells.

Animals↗
PubMed1991

Induction of diabetes by PolyI:C and anti-RT6.1 antibody treatment in DR-BB rats.

To determine whether environmental factors could affect the incidence of diabetes in RT6.1+ lymphocytes-depleted diabetes resistant (DR) BB rats, we tested polyinosinic-polycytidylic acid (Poly I:C), as an immune activator, in conjunction with anti-RT6.1 antibody in DR-BB rats which were bred in a specific pathogen free (SPF) condition. Diabetes was induced by the combined administration of poly I:C and anti-RT6.1 antibody. The use of poly I:C or anti-RT6.1 antibody alone did not cause diabetes. These results suggest that RT6.1+ T lymphocytes regulate autoimmune diabetes and that non-specific immune activation caused by environmental factors plays a key role in inducing diabetes in DR-BB rats.

Animals↗
PubMed1991

Effects of a beta 3-adrenoceptor agonist, BRL 26830A, on insulin and glucagon release in mice.

The beta 3-adrenoceptor agonist, BRL 26830A, which is not inhibited by either beta 1 or beta 2-selective antagonists, has been shown to possess anti-obesity and anti-diabetic actions. However, the effects of this agent on insulin and glucagon release have not yet been substantiated. Therefore, we tested the hypothesis that BRL 26830A promotes insulin and glucagon secretion via beta 3 receptors on pancreatic islet B and A cells. In ICR mice fasted for 48 h, BRL 26830A significantly stimulated insulin secretion from 5 min after administration, markedly decreased blood glucose levels from 30 min after administration, and significantly increased glucagon secretion from 30 min after administration. The administration of a non-selective beta-receptor antagonist, at a dose of 50 mg/kg, 30 min prior to BRL 26830A injection completely abolished the effects induced by BRL 26830A. However, the administration of a beta 1-selective antagonist at doses of 50 or 100 mg/kg did not produce any significant effects. On the action of BRL 26830A, whereas the administration of a beta 2-selective antagonist at 50 mg/kg, a near maximal effective dose, partially abolished the effects of BRL 26830A. BRL 26830A had no effect on insulin, glucagon, or glucose levels in streptozocin (STZ) diabetic mice fasted for 48 h. These results suggest that, in mice, BRL 26830A may promote insulin secretion mainly via beta 3 receptors and partially via beta 2 receptors on pancreatic-islet B cells, and that glucagon may be secreted as the result of hypoglycemia induced by this agent.

Adrenergic beta-Agonists↗
PubMed1991

Reduced brown adipose tissue thermogenesis and metabolic rate in pre-obese mice treated with monosodium-L-glutamate.

To clarify whether reduced brown adipose tissue (BAT) thermogenesis and resting metabolic rate (RMR) are the cause or the consequence of obesity in monosodium-L-glutamate (MSG)-treated mice, we measured guanosine-5'-diphosphate (GDP) binding, and oxygen consumption in the interscapular BAT (IBAT) mitochondria, and the RMR in pre-obese (3-week-old) and obese (12-week-old) MSG-treated mice. Decreases in IBAT mitochondrial GDP binding and oxygen consumption as well as lowered RMR in MSG-treated mice were found even in the pre-obese stage as well as the obese stage, when compared to those in control mice. These findings suggest that reduced BAT thermogenesis may be one of the contributing factors in the development of obesity.

Adipose Tissue, Brown↗
PubMed1991

Effect of zinc-carnosine chelate compound (Z-103), a novel antioxidant, on acute gastric mucosal injury induced by ischemia-reperfusion in rats.

The protective effect of a novel synthetic zinc-carnosine chelate compound, zinc N-(3-aminopropionyl)-L-histidine (Z-103), on the gastric mucosal injury induced by ischemia-reperfusion was studied in rats. Ischemia and reperfusion injury was produced on the rat stomach by applying a small clamp to the celiac artery for 30 min and by removal of the clamp for 30 min. The decrease in the gastric mucosal blood flow was not influenced by the treatment with Z-103. The increase in total area of the erosions on the stomach after ischemia-reperfusion and the increase in lipid peroxides in the gastric mucosa were significantly inhibited by the oral administration of Z-103. In addition, Z-103 inhibited lipid peroxidation of rat brain homogenate and liver microsome in vitro. These results suggest that the protective effect of Z-103 against the aggravation of gastric mucosal injury induced by ischemia-reperfusion may be due to its inhibitory effect on lipid peroxidation.

Animals↗
PubMed1991

[The relationship between complement C3 receptors (CR1, CR3) on polymorphonuclear leukocytes and complement fragments during hemodialysis].

The expression of complement receptor type 1 (CR1) and type 3 (CR3) on polymorphonuclear leukocytes (PMNs) and generation of complement fragments, C3a, C5a, C4d, iC3b and Bb, were studied in patients during hemodialysis using cuprammonium rayon (Cu) membranes. Furthermore, the relation between the expression of CR1 and CR3 on PMNs from healthy donors and complement fragments was investigated. The expression of CR1 and CR3 on PMNs increased during hemodialysis. Plasma C3a, C5a and iC3b levels increased in the first 15 minutes and then decreased at 120 minutes of dialysis. But plasma Bb level remained high until the end of hemodialysis. Purified Bb had no effect on the expression of CR1 and CR3 on PMNs, but C5a augmented those expression in vitro. Nafamostat mesilate, an artificial proteinase inhibitor, inhibited augmentation of complement receptors on PMNs in concentration dependent fashion. C5a generated through the activation of complement was thought to take an important role in the increased expression of CR1 and CR3 on PMNs.

Aged↗
PubMed1991

[Qualitative and quantitative evaluation of CFU-E colonies in myelodysplastic syndromes].

Hemoglobin (Hb) synthesis in colony-forming-unit erythroid (CFU-E) colonies from the bone marrow of 10 normal subjects and 6 patients with myelodysplastic syndromes (MDS) was studied using microcytofluorometry. Hb content was determined utilizing a photochemical reaction in which the intracellular Hb is converted into fluorescent porphyrin. Briefly, the CFU-E in plasma clots was assayed according to Tepperman's method. Bone-marrow mononuclear cells were then dispensed onto petri dishes containing the plasma clots. The cells in plasma clots were cultured for seven days and then air-dried. The samples were then fixed with pure methanol. Thereafter, the dishes were exposed to ultraviolet light (lambda = 405 nm) in the presence of an SH-donor (0.2 M mercaptoethylamine hydrochloride). The intensity of porphyrin fluorescence was measured using a microcytofluorometer. When the photochemical reaction was carried out for 50 min, the intensity of fluorescence was found to be proportional to the mean corpuscular Hb (MCH) level, suggesting that the intracellular Hb level can be determined as a function of the intensity of this fluorescence. The number of CFU-E colonies in MDS patients was smaller than that in normal subjects. In addition, intracolony Hb level was markedly lower in the MDS cases than in normal subjects. Our findings suggest that the maturation process of CFU-E is impaired in MDS patients.

Adult↗
PubMed1991

Establishment of human endothelial cell lines in a serum-free culture and its application for expression of transfected prepro endothelin gene.

Endothelial cells cover the inner layer of vascular tube and are involved in the pathogenesis of some diseases in heart and brain. A development of endothelial cell lines in a serum-free culture lead to our discovery of endothelin (ET) and is expected to be breakthrough for other new fields of medical science. In this paper, we report establishment of vascular endothelial cell lines in serum-free and protein-free culture, transfection of prepro ET cDNA into them, and it's expression and processing to mature ET. A human endothelial cell line, ECV304, has been subcultivated in medium with 10% fetal bovine serum. We tested serum-free culture of this cell line and a several months later, established a cell line, t-HUE2 which would show stable growth in serum-free medium ASF301 containing EGF, insulin, transferrin and albumin as protein components. After additional 12-months' struggle for obtaining a new cell line which can grow without any protein components, we established t-HUE4 cell line which can be subcultivated in basal medium of HamF-12. Although the cell line was derived from human umbilical vein endothelial cells, production and secretion of ET by the cell line into culture medium was not detected with radioimmunoassay method. By transfecting prepro ET cDNA into t-HUE2 and Raji (a human B cell line), we examined the regulation of gene expression in the transformed t-HUE2 and Raji cell lines. The results indicated that all the transformants expressed high level of prepro ET mRNA but that Raji transformant did not produce detectable amounts of ET nor ER precursor protein (big ET). In addition, conversion ratio of ET to big ET in t-HUE2 transformants was much higher than those in normal endothelial cells. Thus, post-transcriptional regulation of prepro ET gene in human B lymphocyte cell line and induction of ET converting enzyme in human vascular endothelial cell line were suggested. In addition to the present study, usefulness of t-HUE2 cell line in serum-free culture for the production of human-type glycoproteins was discussed.

Aspartic Acid Endopeptidases↗
PubMed1991

The effects of overeating on insulin secretion in normal mice.

This study was performed to examine the effect of overeating on in vivo and in vitro insulin secretion in normal mice. Six week old male CRJ-ICR mice were maintained on a cookie and chocolate mashed diet (C.C. diet) until 30 weeks of age; control mice received an ordinary mouse chow. The mice on the C.C. diet (C.C. mice) consumed 125-130% of the daily caloric intake of control mice throughout the study. C.C. mice developed mild hyperglycemia with relative obesity from 16 weeks of age. Fed blood glucose levels at 30 weeks of age for C.C. mice were 158.3 +/- 6.7 mg/dl as opposed to 127.2 +/- 3.1 mg/dl for controls (p less than 0.01). In experimental mice at 18 weeks of age, plasma insulin response after intraperitoneal glucose load (2 mg/g BW) and insulin secretion at 30 mM glucose from the perfused pancreas were similar to those in control mice. However, at 30 weeks of age, insulin secretion at 30 mM glucose from perfused pancreas in C.C. mice was significantly suppressed compared with that of control mice (p less than 0.02). Conversely, in vivo insulin secretory response to intraperitoneal glucose load was significantly increased in C.C. mice (p less than 0.05). There were no differences in insulin secretion at 15 mM glucose from perfused pancreas. These results indicate that impairment of beta-cell secretory capacity develops in impaired glucose tolerant mice with obesity, while in vivo studies show a high insulin response to glucose. This alteration of beta-cell function may be the initial change during the development of the hyperglycemia-induced defect in insulin secretion.

Aging↗
PubMed1991

[Role of oxygen species and lipid peroxidation for anti-tumor effect of intra-arterial injection with degradable starch microspheres].

The role of superoxide and lipid peroxidation for anti-tumor effect of intra-arterial injection with degradable starch microspheres (DSM) was investigated in rabbits. The anti-tumor effect of intra-arterial injection with DSM was studied in rabbits with VX2 carcinoma of the hind leg. The tumor growth in rabbit treated with DSM 5 times was completely suppressed, and thiobarbituric acid (TBA)-reactive substances in the tumor tissue treated with DSM were significantly increased. But the anti-tumor effect of DSM and the increase in TBA reactive substances in the tumor tissue treated with DSM were significantly inhibited by treatment with superoxide dismutase combined with catalase. These results suggest that the anti-tumor effect of intra-arterial injection with DSM may be due to ischemia-reperfusion injury and that active oxygen species and lipid peroxidation may play an important role in the anti-tumor effect of intra-arterial injection with DSM.

Animals↗
PubMed1991

[Chemoembolization with degradable starch microspheres for liver metastases of colorectal cancer].

Transcatheter chemoembolization using degradable starch microspheres (DSM) was performed in 17 patients with liver metastases of colorectal cancer. DSM, 45 microns in diameter, which are easily degraded by serum amylase, and therefore obstruct arterial blood flow temporarily at the arteriolar capillary bed. DSM mixed with mitomycin C were administered through the catheter introduced by Seldinger's method in 13 cases, and through subcutaneously implanted drug delivery system (Port-A-Cath) in 4 cases. The treatment was repeated 5 times on the average at intervals of 2 to 4 weeks. The therapeutic effect of this chemoembolization was evaluated by the change in tumor size measured by angiography or computed tomography. Tumor regression of over 50% was observed in 9 of 17 cases (53%). Elevated serum CEA levels (greater than 10 ng/ml) decreased in 10 of 15 cases (67%). One-year survival rate was 48% in 17 cases, and among them it was 100% in 7 cases with the extent of several liver metastases (H2). Extrahepatic metastasis was observed in 3 of 17 cases (18%) before the treatment, and in 8 cases (47%) after the treatment. Abdominal pain occurred in 36% of the cases by the administration of DSM, but the pain disappeared within 2 hours. No major side effects such as bone marrow suppression or hepatotoxicity were observed. Our results suggest that chemoembolization using DSM is effective and safe in the treatment of liver metastases from colorectal cancer.

Carcinoembryonic Antigen↗
PubMed1991

[Influence of duration of complete global brain ischemia on neurologic outcome in dogs].

The author studied the influence of duration of complete global brain ischemia (CGBI) on neurologic outcome (NO) in dogs. The CGBI of various durations, from 10 to 20 minutes, were induced by clamping of the ascending aorta combined with bypass formation between the aorta and the right atrium. The dogs were divided into four groups according to the duration of CGBI: dogs in group A, B, C or D suffered 10, 15, 18 or 20 minutes of CGBI respectively. In four groups, NOs were evaluated for 7 days after the ischemic insult. In group A, no significant damages were observed and all survived for 7 days. In group B, marked differences in the degree of neurologic deficits were observed, and nearly a half were almost normal and the remainder were severely damaged. In groups C and D, all were so severely damaged as to become vegetative and any difference in the degree of neurologic deficits was not observed among the groups. The author concludes that dogs which have suffered CGBI for 15 minutes or less are not suitable for use in order to evaluate the efficacy of treatments for ischemic brain damage with NOs, and that dogs which suffered CGBI for 18 minutes or more are appropriate for this purpose.

Animals↗
PubMed1991

[Changes in plasma endothelin in patients undergoing cardiac valve replacement under high dose fentanyl anesthesia].

We measured plasma endothelin (ET) in 11 patients undergoing cardiac valve replacement under high dose fentanyl (116.6 +/- 15.4 micrograms.kg-1, mean +/- SD) anesthesia. Arterial blood samples were obtained: 1) before induction of anesthesia (control), 2) just before the start of cardiopulmonary bypass (CPB), and 3) just before the end of CPB. Endothelin levels were analyzed by radioimmunoassay based on double antibody method using Silica ODS suspension. ET concentrations in period 1, 2, and 3 were 3.0 +/- 1.1, 4.2 +/- 1.7 and 4.5 +/- 1.8 pg.ml-1 (mean +/- SD), respectively. There were no significant differences among these three values (P less than 0.05). The results suggest that under high dose fentanyl anesthesia, surgical stress including that of CPB might not affect ET concentration in plasma.

Aged↗
PubMed1991

[Acute unclassified leukemia with bone marrow necrosis].

Massive bone marrow necrosis was seen in a 42-year-old male with acute leukemia. In December, 1988, on admission, laboratory data revealed pancytopenia and a high level of serum LDH and ALKP. Bone marrow aspiration resulted in dry-tap and showed bone marrow necrosis in the bone marrow biopsy specimen. A bone marrow scintigraphy with 111In faintly visualized the bone marrow but visualized area was expanded in the extremities compared with normal subjects. The second bone marrow biopsy showed proliferation of blasts. In the middle of March, blasts began to appear in peripheral blood. The blasts were cytochemically negative for POX, Es, PAS, AcP, TdT and had surface markers CD3-, CD19-, CD33-, CD13-, LCA-, HLA-DR-. Even by investigation on rearrangement of the immunoglobulin heavy chain region, an origin of the blasts could not be determined. In April, the number of blasts in peripheral blood increased and hepatosplenomegaly developed rapidly. Therefore, he was put on the chemotherapy with vincristine and prednisolone, but he died of cerebral hemorrhage. The autopsy revealed widespread bone marrow necrosis. It has rarely been reported that massive bone marrow necrosis is found prior to the occurrence of acute unclassified leukemia.

Acute Disease↗