Biomedical subjects
Publications and source records attributed to M Kubo.
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.
The influence of the 70% methanolic extract (RMe) from Red Ginseng on the lysosome of tumor cells and on the cytocidal effect of mitomycin C (MMC) was investigated. RMe treatment showed an inhibitory effect on the solid form of Ehrlich ascites carcinoma but had no effect on the ascites form. MMC combined with RMe showed stronger antitumor effects, at the same time, the activity of lysosomal enzymes in tumor cells was also increased in comparison with that treated with MMC alone. Furthermore, RMe promoted the uptake of MMC into the tumor cells and enhanced IN VITRO the cytotoxicity of MMC against the cultured tumor cells. From these results it was concluded that RMe labilized the lysosomes of tumor cells IN VIVO, and increased the uptake of MMC into the tumor cells, and that the cytocidal effect of MMC was enhanced by concomitant treatment with RMe.
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.
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.
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.
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.
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 (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.
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.
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.
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.
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.
The antitumor activity of kefir (YK-1), a fermented milk product in Caucasus, was investigated. YK-1 at oral doses of 100 or 500 mg/kg inhibited the proliferation of solid tumor of Ehrlich ascites carcinoma transplanted subcutaneously in mice. YK-1 did not show an inhibitory effect on the ear swelling induced contact dermatitis caused by picryl chloride (PC-CD). However, YK-1 inhibited the immunosuppression in Ehrlich carcinoma-bearing mice and with the frozen and dried ascites of the tumor-bearing mice containing immunosuppressive substances (EC-sup) in PC-CD-induced mice. And also, YK-1 activated the immunosuppressive activity of spleen cells of mouse treated with EC-sup. These results suggest that YK-1 may have antitumor activity against Ehrlich carcinoma and activate the immunosuppression with it.
Effects of water extract (UW-ext) from the leaf of Arctostaphylos uva-ursi (L.) Spreng (Bearberry leaf) on the antiallergic and antiinflammatory activities of dexamethasone ointment were investigated. One or 2% UW-ext ointment did not inhibit the ear swelling by picryl chloride-induced contact dermatitis (PC-CD) and carrageenin-induced paw edema. UW-ext augmented the inhibitory effect of dexamethasone ointment (0.005 or 0.025%) on these allergic and inflammatory models, but not the side effect of it. These results suggest that Bearberry leaf increases the inhibitory effect of dexamethasone on the allergic and inflammatory models.
The aim of this study was to evaluate the late potentials (LPs) in postoperative patients with congenital heart disease (CHD) and to study the association with the clinical characteristics in the postoperative patients with LPs. Signal averaged electrocardiogram (SA-ECG) was recorded in 119 postoperative patients aged 4 to 23 years and compared with those in age matched 49 healthy volunteers with and without right bundle branch block. Based on control data, criterias of LP were defined and altered in the presence of bundle branch block. Abnormal SA-ECGs were not detected in the patients with non-cyanotic CHD. However, abnormal and borderline SA-ECGs were recognized in 5 (12%) of 42 patients after intracardiac operation for tetralogy of Fallot and 3 (30%) of 9 patients after Rastelli's operation. The patients with abnormal and borderline SA-ECGs were significantly older at the time of operation, and had more frequent ventricular arrhythmias (7/8: 3/111, p less than 0.01) and depression of the ST-T segment on ECG (7/8: 11/111, p less than 0.01), compared with the normal SA-ECG group. Abnormal SA-ECGs including those of borderline patients were 50% sensitive and 96% specific for documented ventricular arrhythmias. However, there was no association between abnormalities of SA-ECGs and cardiomegaly on chest X-ray or left ventricular ejection fraction on echocardiogram. These results indicate that prolonged exposure to hypoxia may be the main cause of the primary role in the development of LPs. And late surgical intervention may result in histological background for the development of LPs.
Imidapril is a newly synthesized non-sulfhydryl-containing angiotensin I converting enzyme (ACE) inhibitor. The present study describes the inhibitory effects of imidapril and its active metabolite 6366A on ACEs from various tissues and compares its effects to those of captopril, enalapril and enalaprilat in vitro. 6366A inhibited swine renal and human serum ACEs with an inhibition constant (Ki) of 0.067 nM and 0.04 nM, respectively. These values were 3 to 18 times more potent than those of the other inhibitors. The kinetic study showed that 6366A exerted competitive type inhibition. The ACE inhibition (IC50 values) of 6366A, enalaprilat and the structurally related compounds (6366DM and 6366PY) were compared in homogenates of lung, aorta, heart, brain and kidney from spontaneously hypertensive rats (SHRs) and Wistar Kyoto rats (WKYs). The inhibitory effects of 6366A on all tissue ACEs from SHRs and WKYs were the most potent among these compounds. And the inhibitory potencies of these compounds were correlated with their chemical structure. The present results suggest that 6366A may show a strong inhibitory effect on ACEs from several tissues and species due to its chemical characteristics.
For obtaining the preliminary data on the pathogenesis of sudden death in calves naturally heavily infected with Strongyloides papillosus, we monitored 8 Holstein calves experimentally infected with the larvae on electrocardiographic and pneumographic changes. Six calves died suddenly on days 11 to 17 after infection. Sinus tachycardia had been recorded continuously since 1 to 6 days before death. Heart rates increased gradually until death. Since 1 or 2 days before death, various patterns of tachyarrhythmia and bradyarrhythmia had been observed among patterns of sinus tachycardia. Arrhythmias included serious ventricular premature beat, paroxysmal ventricular tachycardia, complete atrioventricular block and so on. The terminal pattern observed suddenly in all of the cases was ventricular arrhythmias consisting of serial ventricular tachycardia, flutter and fibrillation, which were followed by respiratory arrest. Abnormal pneumograms were not obtained before the terminal ventricular fibrillation. Two of 8 calves recovered from the infection, only one of which showed sinus arrest and the second degree of atrioventricular block transiently. We concluded that calves heavily infected with the larvae died due to sudden cardiac arrest.
We examined the changes in serum human hepatocyte growth factor (hHGF), also called "scatter factor," levels after transcatheter arterial embolization (TAE) and partial hepatectomy (PH) in patients with hepatocellular carcinoma and metastatic liver tumor. In most cases, the serum hHGF levels increased transiently 1-3 days after TAE or PH, and then decreased nearly to the basal levels in 1 wk, suggesting that hHGF may play an important role in liver regeneration in humans. The mean amount of increase in serum hHGF levels after PH was 0.38 ng/ml, which was greater than that after TAE (0.16 ng/ml). In three cases of TAE followed by PH, two showed a greater increase in serum hHGF levels with PH than with TAE, but the third showed the reverse result. Because the rate of increase in serum ALT levels did not affect that of serum hHGF levels, the degree of liver injury induced by TAE or PH does not seem to be a determinant in serum hHGF elevation.