Biomedical subjects
M Kubo
Publications and source records attributed to M Kubo.
Stimulation of the activity and mRNA level of hepatic triacylglycerol lipase by triiodothyronine in HepG2 cells.
We have studied the effects of triiodothyronine (T3) on the production of hepatic triacylglycerol lipase (HTGL) in the human hepatocellular carcinoma cell line, HepG2, by measuring its activity and mRNA levels. The HTGL activity released into the medium by heparin, increased after the addition of T3 in a both time- (27% increase after 24 and 75% increase after 48 h) and dose-dependent manner (maximum activity with over 0.2 micrograms/ml of T3 in the medium). Messenger RNA levels of HTGL in cells incubated with T3 for 24 and 48 h were increased by 33% and 98% compared to those of the control. These results suggest that the production of HTGL may be regulated by thyroid hormone at the level of gene expression.
Exocytosis upon osmotic swelling in human epithelial cells.
Upon osmotic swelling human epithelial cells exhibited significant increases in the membrane capacitance. Evidence for exocytosis includes its dependency on temperature, cytosolic Ca2+ and ATP as well as its sensitivity to guanosine 5'-O-(3-thio)triphosphate (GTP gamma S) and N-ethylmaleimide (NEM). A role of the osmotic exocytosis in the subsequent cell volume regulation is suggested.
Antibodies to native type III collagen in the serum of patients with Kawasaki disease.
Pathological studies have revealed that the vasculitis in Kawasaki disease (KD) begins in the intima and the adventitia of blood vessels resulting in panvasculitis. In the present study we investigated the possibility that auto-antibodies to types III and II collagen are involved in the vascular injury. Seven out of 38 patients (18%) with KD had elevated serum levels of IgG antibody to type III collagen. None had increased serum antibodies to type II collagen. Specificity of the antibody to type III collagen in patients with KD was 86%. Three out of seven KD patients (42.9%) with coronary complications had elevated serum levels of the antibody. It is conceivable that the more severe the inflammation of systemic blood vessels, the more frequently antibodies to type III collagen are detected and coronary complications develop. Accordingly, this antibody may be secondarily detected in the serum of KD when systemic blood vessels are severely damaged. Detection of antibodies to type III collagen might be a risk factor predicting coronary complications.
Non-macrophage-related accumulation of cholesterol during probucol treatment in familial hypercholesterolemia: report of two cases.
Two patients receiving long-term (3-4 years) treatment with probucol for familial hypercholesterolemia (FH) developed diffuse yellow lesions over the upper eyelids suggesting lipid storage in those tissues (diffuse lipid-storage lesions). Interestingly, each patient had shown a substantial reduction in their cholesterol levels together with a marked regression of their tendon xanthomas or typical xanthelasmas during treatment. To evaluate the role of probucol in this unusual finding we conducted histological and immunochemical evaluations of the lesions (removed surgically) and compared them with those of a non-probucol-treated subject with FH and typical audinal xanthelasma. In both probucol-treated patients the lesions were filled with foam cells and contained large amounts of cholesteryl ester. However, immunochemical analysis of the lesions of one patient using anti-monocyte monoclonal antibody (HAM56) demonstrated that they were not composed of macrophage-derived foam cells in contrast to those of the non-probucol-treated subject which stained clearly with anti-monocyte monoclonal antibody. In each case the foam cells did not react with muscle-actin-specific monoclonal antibody (HHF35). It appears that non-macrophage-related diffuse lipid-storage lesions may occur even during treatment with probucol despite the reduction in cholesterol levels and the regression of xanthomas, suggesting that probucol may alter the distribution of cholesterol from the macrophage to other cells.
Polydisperse low-density lipoproteins in hyperalphalipoproteinemic chronic alcohol drinkers in association with marked reduction of cholesteryl ester transfer protein activity.
Long-term heavy alcohol intake is well known to increase serum high-density lipoprotein (HDL) cholesterol concentrations. Epidemiologic studies have shown that the protective effect of alcohol intake against coronary heart disease (CHD) is observed in moderate alcohol drinkers, but not in heavy ones. To clarify whether heavy alcohol intake may cause abnormalities in lipoprotein metabolism, we analyzed the plasma lipoproteins in eight male chronic heavy alcohol drinkers with marked hyperalphalipoproteinemia. Although their serum HDL cholesterol levels were remarkably high, ranging from 2.67 to 3.58 mmol/L, three patients had CHD and corneal arcus was present in seven patients. Cholesteryl ester transfer protein (CETP) activity was reduced in all subjects (7.3% +/- 4.2%/10 microL/18 h in alcohol drinkers v 20.5% +/- 2.4%/10 microL/18 h in control; mean +/- SD, P < .001). The CETP mass levels were also markedly reduced in these subjects. The analysis of low-density lipoprotein (LDL) on nondenaturing polyacrylamide gradient gel electrophoresis revealed that four subjects with severely low CETP activity (< 25% of control) had polydisperse LDLs, similar to those observed in genetic CETP deficiency. The other four subjects with approximately half the normal CETP activity had homogeneous but smaller-sized LDLs, as compared with control subjects. Particle size of HDL was larger than that of normal control HDL in all subjects. After cessation of alcohol intake, plasma HDL cholesterol levels were decreased and LDLs became more homogeneous and normal in size, in parallel with elevation of CETP activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Sudden death of calves by experimental infection with Strongyloides papillosus. I. Parasitological observations.
Recently, an unknown disease, 'sudden death', in calves has been found in Japanese beef production farms. A previous study conducted by Taira and Ura indicated that sudden death can be effected in calves by hyperinfection of Strongyloides papillosus (SPL) and that the disease is possibly caused by SPL infection. In the present work, an experimental infection of SPL in calves was conducted to confirm the field occurrence. Fifteen Holstein Friesian calves, ranging from 45.5 to 85.6 kg in body weight, were divided into six groups. Calves of Groups A, B, C, D, E and F were infected once at the rate of 100,000, 320,000, 1,000,000, 3,200,000, 10,000,000 and 32,000,000 SPL larvae per 100 kg of body weight, respectively. Five calves were assigned to Group B, while two calves were assigned to the other groups. After showing no premonitory signs, sudden death of ten calves took place. The survival time of these calves was 27.4 and 16.8 days (Group B), 14.8 and 14.8 days (Group C), 13.3 and 14.2 days (Group D), 11.0 and 11.1 days (Group E) and 11.6 and 10.8 days (Group F). Three calves of Group B did not exhibit sudden death. The results of this study demonstrate that strongyloidiasis was the cause of sudden death.
Isolation of Fukuoka virus, a member of the Kern Canyon serogroup viruses of the family Rhabdoviridae, from cattle.
Four virus strains with identical antigenic properties were isolated from blood samples of 4 sentinel calves having a fever and leukopenea in cultures of HmLu-1 cells derived from baby hamster lung. The virus was identified as Fukuoka virus, classified as a member of the Kern Canyon serogroup viruses of the family Rhabdoviridae, on the basis of its antigenic properties.
Volume-regulatory Cl- channel currents in cultured human epithelial cells.
1. During osmotic swelling, cultured human small intestinal epithelial cells (Intestine 407) exhibited activation of large Cl- currents under the patch-clamp whole-cell configuration. The volume-sensitive Cl- conductance was independent of intracellular Ca2+ and cyclic AMP. 2. The anion permeability sequence of the current was SCN- > I- > Br- > Cl- > F- > gluconate-, corresponding to Eisenman's sequence I. 3. Cl- currents were instantaneously activated by command pulses in a range of -120 to +45 mV. At potentials more positive than +50 mV the current showed a time-dependent inactivation. This inactivation was accelerated by increased depolarization. The instantaneous current-voltage relationship rectified in the outward direction. 4. A stilbene-derivative Cl- channel blocker, 4-acetamido-4'-isothiocyanostilbene (SITS), inhibited the Cl- current at micromolar concentrations. SITS facilitated inactivation at positive potentials. Outward currents were more prominently suppressed by SITS than inward currents. The concentrations required for 50% inhibition (IC50) of outward and inward currents were 1.5 and 6 microM, respectively. The outward and inward currents were equally inhibited by a carboxylate analogue Cl- channel blocker, 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) or diphenylamine-2-carboxylate (DPC) at higher doses (IC50 = 25 for NPPB or 350 microM for DPC). Inactivation kinetics at large depolarizations was not affected by NPPB or DPC. 5. The Cl- current was blocked by an unsaturated fatty acid, arachidonic acid (IC50 = 8 microM). Arachidonic acid was still effective in the presence of inhibitors of lipoxygenase (nordihydroguaiaretic acid, 10 microM), cyclo-oxygenase (indomethacin, 10 microM) and protein kinase C (polymyxin B, 30 microM). The Cl- current was also sensitive to another cis unsaturated fatty acid, oleic acid, which is not a substrate for oxygenases. A trans isomer of oleate, elaidic acid, and a saturated fatty acid, palmitic acid, were ineffective. 6. Single Intestine 407 cells exposed to a hypotonic solution showed a regulatory volume decrease after initial osmotic swelling. The volume regulation was abolished by SITS, NPPB, arachidonate and oleate, but not by elaidate and palmitate. 7. It is concluded that outwardly rectifying Cl- channels, which are sensitive to arachidonic acid, are activated upon osmotic swelling and involved in the subsequent cell volume regulation.
[Clinical studies on pediatric purulent meningitis--clinical symptoms and prognosis].
In 149 patients with purulent meningitis we encountered in the period of 20 years from 1970 to 1990, their clinical symptoms and prognosis were investigated. Death or sequela was noted in many of the patients having loss of consciousness, stiffness of the members and/or cyanosis as primary clinical symptoms, or having hypoalbuminemia (less than 2.5 g/dl) and/or thrombocytopenia as abnormal laboratory findings, or having excessive protein levels and/or excessively low sugar levels in cerebro-spinal fluid. Early initiation of adequate antibiotic therapy, as well as symptomatic treatment using transfusion, steroids and anticonvulsants, are important.
[Clinical studies on pediatric purulent meningitis--statistical analysis of etiology and therapy].
In a total of 149 children with purulent meningitis we encountered in our institute in the last 20 years, the causatives, the changes in therapeutic management and the prognosis were investigated. The causatives could be detected in 109 patients (73%): H. influenzae; 30 patients (20%), S. pneumoniae; 18 patients (12%), E. coli; 13 patients (9%), GBS; 7 patients (5%) and S. aureus; 6 patients (4%). These five causatives were detected in 49% of the total patients, or 67% of the patients in whom causatives could be detected. Of these five causatives, E. coli were detected the most frequently in the first half of 1970's, but, in recent years, the detection of GBS, S. pneumoniae and H. influenzae has been remarkably increasing. In spite of progress in antibiotics, the prognosis of the disease due to S. pneumoniae, GBS and S. aureus was poor. In the majority of the patients who died, the death came within five days after hospitalization due to loss of consciousness, convulsion etc. It is therefore necessary not only to initiate strong antibiotic treatment as soon as possible after early diagnosis, but also to take symptomatic measures such as steroidal treatment, treatment of shock etc.
Alteration of specific activity and stability of thermostable neutral protease by site-directed mutagenesis.
On the basis of three-dimensional information, many amino acid substitutions were introduced in the thermostable neutral protease (NprM) of Bacillus stearothermophilus MK232 by site-directed mutagenesis. When Glu at position 143 (Glu-143), which is one of the proposed active sites, was substituted for by Gln and Asp, the proteolytic activity disappeared. F114A (Phe-114 to Ala), Y110W (Tyr-110 to Trp), and Y211W (Tyr-211 to Trp) mutant enzymes had higher activity (1.3- to 1.6-fold) than the wild-type enzyme. When an autolysis site, Tyr-93, was replaced by Gly and Ser, the remaining activities of those mutant enzymes were higher than that of the wild-type enzyme.
Prediction of advanced puberty by height velocity in children with acute lymphoblastic leukemia.
Pubertal development was retrospectively evaluated in 58 children with cancer, mostly acute lymphoblastic leukemia (ALL), who are in complete remission and off chemotherapy. Six girls [5 patients with ALL, and 1 with malignant lymphoma (NHL)] showed advanced puberty (25.0%, 6 of 24 female patients with ALL and NHL) through the evaluation of their growth velocity. No evidence for advanced puberty was seen in the males. All 6 girls had received cranial irradiation for central nervous system prophylaxis and systemic chemotherapy including glucocorticoid. The mean age at onset of the pubertal growth spurt in these 6 girls was significantly lower than for girls with a solid tumor [6.90 +/- 0.10 and 9.00 +/- 0.77 (mean +/- SD) years, respectively (p < 0.01)]. By simply evaluating the height velocity, we could predict advanced puberty which was ultimately associated with short stature.
Effects of long-term administration of (4S)-1-methyl-3-[(2S)-2-[N-((1S)-1-ethoxycarbonyl-3- phenylpropyl)amino]propionyl]-2-oxoimidazolidine-4-carboxylic acid hydrochloride (TA-6366), a new angiotensin I converting enzyme (ACE) inhibitor, from the pre-hypertensive stage on morphological change and mechanical property related to sodium ion permeability in aorta of spontaneously hypertensive rats (SHRs).
Effects of (4S)-1-methyl-3-[(2S)-2-[N-((1S)-1-ethoxycarbonyl-3-phenylpropyl)amino]- propionyl]-2-oxoimidazolidine-4-carboxylic acid hydrochloride (TA-6366) on morphological change and mechanical property related to sodium ion permeability in the aorta of spontaneously hypertensive rats (SHRs) were examined, as compared with those of enalapril and captopril. Ten-week oral administration of TA-6366 (1 and 5 mg/kg/d) from 4 weeks of age impeded aortic media-thickening together with a rise in blood pressure in SHRs. Concomitantly, aorta weights in both groups were markedly decreased. The higher dose of TA-6366 almost fully suppressed the accelerated tension development induced by K(+)-free medium and decreased total sodium ion content in the aorta. These vascular effects of TA-6366 was more prominent than those of enalapril and captopril at 5 mg/kg/d. The difference in potencies on the above vascular parameters between TA-6366 and these drugs seemed to be mainly related to the difference in their antihypertensive activities. These results suggest that TA-6366 has preventive effects against progression of vascular diseases, particularly atherosclerosis, accompanied with hypertension.
[Pharmacological study on Panax ginseng C. A. Meyer. XIV. Effect of 70% methanolic extract from red ginseng on the cytocidal effect of mitomycin c against rat ascites hepatoma AH 130].
The influence of the 70% methanolic extract (RMe) from Red Ginseng (a steamed and dried root of Panax ginseng C. A. Meyer) on the antitumor activity of mitomycin C (MMC) against rat ascites hepatoma AH 130 was investigated. In the case of a solid tumor, RMe at oral doses of 200, 500 mg/kg showed an inhibitory effect, but RMe was ineffective in the case of an ascites tumor. MMC combined with RMe showed a stronger antitumor effect than MMC alone. Moreover, RMe inhibited the pulmonary metastases of the tumor cells, as well as the decrease of blood platelet counts and of the fibrinogen level induced by the infusion of the tumor cells in rats. Furthermore, RMe promoted the uptake of MMC into the tumor cells and enhanced in vitro the cytotoxicity of MMC against the cultured tumor cells.
[Pharmacological study on Panax ginseng C. A. Meyer. XV. Effects of 70% methanolic extract from red and white ginseng on the antitumor activity of mitomycin C].
The influence of various fractions and ginsenosides from the 70% methanolic extract (RMe) of Red Ginseng (a steamed and dried root of Panax ginseng C. A. Meyer) on the cytocidal effect of mitomycin C (MMC) against Ehrlich ascites carcinoma was investigated in vitro. The AcOEt soluble portion (RMe-I) showed an increasing effect on the activities of lysosomal enzymes in the cultured tumor cells. RMe-I promoted the uptake of MMC into the tumor cells and enhanced the cytotoxicity of MMC against the cultured tumor cells. 20(S)-, 20(R)-ginsenoside Rg3 and ginsenoside Rh2 isolated from RMe-I promoted the uptake of MMC into the tumor cells but ginsenosides from the n-BuOH soluble portion (RME-II) had no effect. Furthermore, the influence of RMe and the 70% methanolic extract (WMe) from White Ginseng (a dried root of Panax ginseng C. A. Meyer) on the cytocidal effect of MMC was investigated in vivo. MMC combined with RMe showed stronger antitumor effects against the ascites form of mouse Ehrlich ascites carcinoma and rat ascites hepatoma AH 130 than MMC combined with WMe. The activities of lysosomal enzymes in tumor cells were also more increased in comparison with that combined MMC and WMe.
[Pharmacological study on Naja naja kaouthia Lesson. III. Effects of 50% ethanolic extracts from liver and gall bladder on phagocytic activity of mouse reticuloendothelial system].
Effects of 50% ethanolic extracts from the liver and the gall bladder of Naja naja kaouthia Lesson (COB-L or COB-G) were studied on the phagocytic activity of a mouse reticuloendothelial system. The clearance-rate of carbon was shortened by the oral administration of COB-L or COB-G (50 or 200 mg/kg). COB-L or COB-G promoted the phagocytosis of latex by peritoneal macrophages (M phi). Furthermore, effects of these extracts on the peritoneal M phi were biochemically investigated using in vitro experimental models. The activities of two lysosomal enzymes, acid phosphatase and beta-glucuronidase, and that of lactate dehydrogenase in the peritoneal M phi were enhanced when the M phi were cultured with COB-L or COB-G (10-100 micrograms/ml) for 4 d. In addition, the consumption of glucose in the culture media by the M phi was also enhanced by culturing the media with COB-L or COB-G. When COB-L and COB-G were given orally immediately before and 16 h after the application of picryl chloride (PC) or sheep red blood cell (SRBC), these extracts at a dose of 200 mg/kg did not show any inhibitory effects on the swelling by picryl chloride-inducing contact dermatitis (PC-CD) and by sheep red blood cell delayed type hypersensitivity (SRBC-DTH) in mice. However, these extracts inhibited the immunosuppression with the SRBC 1 x 10(9) cells priming and with the frozen and dried ascites of Ehrlich carcinoma-bearing mice containing immunosupressive substances (EC-sup). These results suggest that COB-L or COB-G biochemically activates the mouse peritoneal M phi, and promotes the phagocytic activity of the M phi and the interaction between M phi and T cell.
[Pharmacological studies on leaf of Arctostaphylos uva-ursi (L.) Spreng. IV. Effect of 50% methanolic extract from Arctostaphylos uva-ursi (L.) Spreng. (bearberry leaf) on melanin synthesis].
Effects of 50% methanolic extract (U-ext) from the leaf of Arctostaphylos uva-ursi (L.) Spreng. (bearberry leaf) on melanin synthesis were investigated in vitro. The U-ext and arbutin isolated from the bearberry leaf had an inhibitory effect on tyrosinase activity. Furthermore, the U-ext inhibited the production of melanin from dopa by tyrosinase and from dopachrome by autoxidation. These results suggest that the bearberry leaf was found to be an effective inhibitor of the production of melanin.