Biomedical subjects

T Namba

Publications and source records attributed to T Namba.

At least 73 records · Page 4Linked to original sources

PubMed1998

[Identification of Tougucao derived from Clematis species].

Comparative studies were carried out on the morphology and histology of 5 Clematis species, namely, C. intricata, C. aethusifolia, C. glauca, C. tangutica and C. hexapetala, allegedly used as "Tougucao". New characteristics, a sclerenchymatous ring composed of primary phloem fibers and lignified parenchyma cells, and a parenchymatous tertiary ring were discovered. A parameter representing the ratio of the diameter of cambium ring to the diameter of the stem (RCR) is created. A key for identification of the stems of the above five species is made according to the presence or absence of the sclerenchymatous ring, the diameter and numbers of hair cells, the thickness of fiber wall and the value of RCR, etc.

Magnoliopsida↗

PubMed1998

[Studies on flavonoids from Fenugreek (Trigonella foenumgraecum L.)].

OBJECTIVE: To study the flavonoids in fenugreek (Trigonella foenumgraecum) produced in China. METHOD: The flavonoids were isolated with silica gel, polyamide and Sephadex LH-20 chromatography, and their structures were identified by physical, chemical properties and spectral analysis. RESULT: Five flavonoid compounds were isolated from fenugreek seeds and identified as vitexin, tricin, naringenin, quercetin and tricin-7-O-beta-D-glucopyranoside. CONCLUSION: Three flavonoids, tricin, naringenin and tricin-7-O-beta-D-glucopyranoside, were isolated from fenugreek as well as from the plants of Trigonella for the first time.

Apigenin↗

PubMed1998

Purification and characterization of eugeniin as an anti-herpesvirus compound from Geum japonicum and Syzygium aromaticum.

The hot-water extract of Geum japonicum has been shown to exhibit prophylactic and therapeutic anti-herpes simplex virus (HSV) activity in murine infection models. Eugeniin was purified as an anti-HSV compound from the extract and also was isolated from another herbal extract (Syzygium aromaticum) that had exhibited anti-HSV activity in mice. Thus the anti-HSV action of eugeniin was characterized. The effective concentration (5.0 microg/ml) for 50% plaque reduction of eugeniin for wild HSV type 1 (HSV-1) on Vero cells was 13.9-fold lower than its 50% cytotoxic concentration determined by a yield-reduction assay. Eugeniin also inhibited the growth of acyclovir-phosphonoacetic acid-resistant HSV-1, thymidine kinase-deficient HSV-1 and wild HSV type 2. Eugeniin as well as phosphonoacetic acid inhibited viral DNA and late viral protein syntheses in their infected Vero cells, but not cellular protein synthesis at its inhibitory concentrations. Purified HSV-1 DNA polymerase activity was inhibited by eugeniin noncompetitively with respect to dTTP. Its apparent Ki value for euginiin was 8.2- and 5. 8-fold lower than the Ki values of purified human DNA polymerases alpha and beta, respectively. Thus one of the major target sites of inhibitory action of eugeniin is viral DNA synthesis; the inhibitory action for viral DNA polymerase activity was novel compared with anti-HSV nucleoside analogs.

Animals↗

PubMed1998

Tibioperoneal bypass for popliteal arterial occlusion.

OBJECTIVE: To clarify the clinical features of chronic arterial occlusive disease in which the main lesion occurs in the popliteal artery (OPA). EXPERIMENTAL DESIGN: This was a retrospective study with a follow-up of 1 to 163 months. SETTING: A department of surgery in a university hospital. PATIENTS: Fifty-six patient who underwent tibioperoneal bypasses: 31 patients with OPA, and 25 with an extensive occlusive lesion from the femoral to popliteal artery (OFPA). INTERVENTION: All bypasses were performed using reversed saphenous veins under tourniquet ischemia. MEASUREMENTS: The background of the patients and the surgical results, including long-term patency and postoperative arteriographic findings. RESULTS: Buerger's disease occurred most commonly in the OPA group (49%) and arteriosclerosis obliterans occurred most commonly in the OFPA group (64%). The 3-year primary and secondary cumulative patency rates of the grafts for OPA were 72% and 85% respectively, and were comparable with those of OFPA. Arteriographic analyses carried out in the follow-up period revealed no occlusive progression in the inflow artery. CONCLUSIONS: Popliteal-distal bypass is a reliable procedure in selected patients with OPA.

Adult↗

PubMed1997

Regulation of fibrillar collagen gene expression and protein accumulation in volume-overloaded cardiac hypertrophy.

BACKGROUND: Interstitial collagen accumulation has been extensively demonstrated to be increased at both mRNA and protein levels in pressure-overloaded cardiac hypertrophy. However, few data are available regarding the effects of volume overload on myocardial collagens. METHODS AND RESULTS: To determine whether the alterations of collagens may occur in volume-overloaded cardiac hypertrophy, we measured collagen types I and III mRNA levels and protein accumulation in left ventricular (LV) myocardium of rats at 3, 7, and 28 days after the creation of an aortocaval (AC) shunt. Eccentric LV hypertrophy was produced in rats with AC shunting. Northern blot analysis on RNA extracted from LV tissue indicated that the steady state mRNA levels for both type I and III collagen were persistently upregulated in AC shunt rats compared with sham-operated operated control rats. In contrast, the biochemical collagen protein concentration and morphometric collagen volume fraction were comparable between sham-operated control and AC shunt rats at any study time point. Furthermore, the immunohistochemical staining of types I and III collagen and Sirius red staining on myocardial tissue sections revealed no significant alterations in the distribution or density of fibrillar collagens in AC shunt rats. Tissue collagenase activity was not different between control and AC shunt rats after 28 days. CONCLUSIONS: Cardiac volume overload increases LV collagen mRNA as does pressure overload. However, in contrast to pressure-overloaded hypertrophy, the upregulation of collagen transcriptional activity does not result in subsequent myocardial fibrosis in volume-overloaded hypertrophy due to AC shunting. Therefore, the upregulation of collagen gene expression and protein accumulation might be different in pressure-overloaded and volume overloaded hypertrophy.

Animals↗

PubMed1997

Rapid postincubation endothelial retention by Dacron grafts.

Defining the most appropriate conditions for strengthening the retention of endothelial cells (ECs) by small-diameter prosthetic endothelialized grafts is indispensable to their clinical application. The incubation time after seeding is one of the most important factors in EC retention. The effects of different postincubation times (0, 2, 4, 8, 16, 24, and 36 hr) on EC monolayers on two different types of graft, fibronectin-coated expanded polytetrafluoroethylene (ePTFE) and collagen-coated knitted Dacron grafts (4 mm x 5 cm) were examined. In situ counting of ECs on the grafts was performed by light microscopy. The percentage cell retention was calculated by dividing the cell counts for grafts exposed to pulsatile flow for 90 min by those for control grafts. To characterize the EC coverage of the grafts, scanning electron microscopy was also performed. The average cell density of control grafts ranged from 5.59 +/- 1.1 to 6.69 +/- 1.5 x 10(4) cells/cm2 and did not differ according to the kind of graft or incubation time. The knitted Dacron grafts showed the maximal cell retention (88 +/- 5%) after incubation for 8 hr, whereas ePTFE grafts did so after 24 hr (83 +/- 6%). Scanning electron microscopic examination after incubation for 8 hr revealed that the density of human ECs on the surfaces of ePTFE and Dacron grafts differed, although there was no morphological difference between the ECs on the two types of graft. Knitted Dacron grafts achieved a high percentage retention in a shorter time than ePTFE grafts.

Blood Vessel Prosthesis↗

PubMed1997

Adenovirus-mediated transfer of tissue-type plasminogen activator gene to human endothelial cells.

BACKGROUND: Seeding of vascular grafts with genetically engineered human endothelial cells (hECs) secreting antithrombogenic or fibrinolytic agents has considerable clinical potential. METHODS: An adenoviral vector was used to transfer the human tissue-type plasminogen activator (htPA) gene to hECs, and the ability of the transduced hECs to secrete htPA was examined. Cultured hECs on plates were incubated with various concentrations of recombinant adenoviruses containing the htPA or LacZ gene for various times to determine the optimal transfer conditions. Transduced hECs were seeded onto fibronectin-coated expanded polytetrafluoroethylene grafts (4 mm in diameter), some of which were exposed to pulsatile flow in vitro. RESULTS: Effective transduction of the htPA gene into hECs (htPAhECs) was achieved with viral soup at a multiplicity of infection of 30 after incubation for 1 day, which yielded 4.8 +/- 0.20 x 10(3) ng/10(6) cells/6 hr htPA antigen on plates (n = 3), 2.2 +/- 2.0 x 10(3) ng/10(6) cells/6 hr on grafts (n = 6), and 6.8 +/- 1.7 x 10(2) ng/10(6) cells/6 hr on perfused grafts (n = 6). The retention of htPAhECs by perfused grafts was 84.0% +/- 3.0%, comparable with the noninfected (82.1% +/- 8.0%) and mock-infected (94.2% +/- 0.4%) hEC values. CONCLUSIONS: By adenoviral vector-mediated gene transfer, 10(2-3)-fold enhancement of htPA secretion was demonstrated, which did not affect cell retention by grafts.

Adenoviridae↗

PubMed1997

Intraoperative evaluation of small-calibre arterial reconstructions.

A new hammerhead-shaped, small probe for intraoperative duplex ultrasound was devised to evaluate small-calibre arterial reconstructions. This probe was used in two patients; one with terminal liver cirrhosis who had a left hepatic lobe that had been transplanted from her mother, and a second patient with limb-threatening ischaemia who had undergone arterial reconstructions. The technique was diagnostically useful and contributed to successful clinical outcomes.

Adolescent↗

PubMed1997

Prophylactic efficacy of traditional herbal medicines against recurrent herpes simplex virus type 1 infection from latently infected ganglia in mice.

Traditional herbal medicines with anti-herpes simplex virus type 1 (HSV-1) activity in vivo were examined for their prophylactic effects on recurrent HSV-1 infection in mice. Mice were intradermally infected with HSV-1 in the pinna and recurrent HSV-1 disease was induced by ultraviolet irradiation. Herbal extracts arrested the progression of recurrent HSV-1 disease, reduced the incidence of severe erythema and/or vesicles in the pinna, and/or shortened the period of severe recurrent lesions compared with water-administered mice (P < 0.01 or 0.05). Similarly, the prophylactic treatment of herbal extracts limited the development of recurrent skin lesions induced by stripping with cellophane tape physically. The prophylactic efficacy on recurrence was confirmed by the absence of HSV DNA in the skin lesions. HSV-1 genome was revealed to exist in the trigeminal ganglia but not in the pinna of latently infected mice before stimuli by a nested-polymerase chain reaction assay. After stimuli, HSV-1 genome was detected in both pinna and trigeminal ganglia of latently infected mice administered with water. However, prophylactic treatment decreased the rate of detection of HSV-1 genome in the stimulated pinna. Thus, the herbal extracts exhibited prophylactic efficacy against recurrent HSV-1 disease in mice and modulated the recurrent HSV-1 infection.

Animals↗

PubMed1997

Antibacterial activity of trichorabdal A from Rabdosia trichocarpa against Helicobacter pylori.

Rabdosia trichocarpa is used in a popular home-made remedy for gastric and stomachic complaints in Japan. A diterpene, trichorabdal A from R. trichocarpa, showed a very strong in vitro antibacterial activity against Helicobacter pylori. With regard to the antibacterial activity of the extract and constituents of R. trichocarpa against H. pylori, the effect of traditional use of this plant for the treatment of gastritis is probably due to the suppression of H. pylori since the extract of R. trichocarpa particularly inhibits the growth of H. pylori. It could be a promising native herb treatment for patients with gastric complaints including gastric ulcer caused by H. pylori.

Anti-Bacterial Agents↗

PubMed1997

Role of nitric oxide towards vasodilator effects of substance P and ATP in human forearm vessels.

1. It has been shown in animals that substance P as well as acetylcholine releases endothelium-derived nitric oxide and evokes vasodilatation and that ATP-induced vasodilatation is partially mediated by nitric oxide. The aim of this study was to examine whether vasodilator effects of substance P and ATP are mediated by nitric oxide in humans. 2. In healthy volunteers (n = 35), we measured forearm blood flow by a strain-gauge plethysmograph while infusing graded doses of acetylcholine, substance P, ATP or sodium nitroprusside into the brachial artery before and after infusion of NG-monomethyl-L-arginine (4 or 8 mumol/min for 5 min). In addition, we measured forearm blood flow while infusing substance P before and during infusion of L-arginine (10 mg/min, simultaneously), or before and 1 h after oral administration of indomethacin (75 mg). 3. Acetylcholine, substance P, ATP or sodium nitroprusside increased forearm blood flow in a dose-dependent manner. NG-Monomethyl-L-arginine decreased basal forearm blood flow and inhibited acetylcholine-induced vasodilatation but did not affect substance P-, ATP-, or sodium nitroprusside-induced vasodilatation. Neither supplementation of L-arginine nor pretreatment with indomethacin affected substance P-induced vasodilatation. 4. Our results suggest that, in the human forearm vessels, substance P-induced vasodilatation may not be mediated by either nitric oxide or prostaglandins and that ATP-induced vasodilatation may also not be mediated by nitric oxide.

Acetylcholine↗

PubMed1997

Preventive effect of lithospermate B from Salvia miltiorhiza on experimental hepatitis induced by carbon tetrachloride or D-galactosamine/lipopolysaccharide.

The water extract from the root of Salvia miltiorhiza Bunge showed a protective effect on cultured rat hepatocytes against carbon tetrachloride (CCl4)-induced necrosis. A further study was carried out to isolate the active constituent. Activity guided fractionation of the extract and chemical analysis gave us lithospermate B (a salt of lithospermic acid B), a tetramer of caffeic acid. Lithospermate B was also found to have a potent hepatoprotective activity in not only in vitro but also in vivo experimental liver injuries induced by CCl4 or D-galactosamine (D-GalN)/lipopolysaccharide (LPS).

Animals↗

PubMed1997

Immunostimulating activity of Celosian, an antihepatotoxic polysaccharide isolated from Celosia argentea.

Celosian, an acidic polysaccharide from the seeds of Celosia argenteo (Amaranthaceae) was found to be a potent antihepatotoxic agent for chemical and immunological liver injury models in animals. The immunomodulating action of celosian was studied to clarify the preventive mechanism of celosian on liver injuries. Celosian induced tumor necrosis factor-alpha (TNF-alpha) production in mice. Celosian also induced the production of interleukin-1 beta (IL-1 beta) and nitric oxide (NO) in macrophage cell line J774.1 in a concentration-dependent manner (1 to 1000 micrograms/ml). Moreover, celosian induced IL-1 beta secretion in human mononuclear cells. In addition, celosian enhanced gamma interferon (IFN-gamma) production activity of concanavalin A (Con A) in mice spleen cells, though celosian alone did not significantly influence IFN-gamma production. These results indicate that celosian is an immunostimulating agent in addition to antihepatotoxic effects.

Adjuvants, Immunologic↗

PubMed1997

Effects of intracoronary fentanyl on left ventricular mechanoenergetics in the excised cross-circulated canine heart.

BACKGROUND: It is still unclear whether fentanyl directly alters left ventricular (LV) contractility and oxygen consumption. This is because of the difficulty in defining and evaluating contractility and energy use independently of ventricular loading conditions and heart rate in beating whole hearts. METHODS: This study was conducted to clarify the mechanoenergetic effects of intracoronary fentanyl in six excised cross-circulated canine hearts. The authors used the framework of the E(max) (a contractility index)-PVA (systolic pressure-volume area, a measure of total mechanical energy)-VO2 (myocardial oxygen consumption per beat) relationship practically independent of ventricular loading conditions. The authors measured LV pressure, volume, coronary flow, and arteriovenous oxygen content difference to calculate E(max), PVA, and VO2. They first obtained the VO2-PVA relationship for varied LV volumes at control E(max). The authors then obtained the VO2-PVA relationship at a constant LV volume, whereas coronary blood fentanyl concentration was increased in steps up to 240 ng/ml. Finally, they obtained the VO2-PVA relationship for varied LV volumes at the final dose of fentanyl. RESULTS: Fentanyl at any concentrations did not significantly change E(max), PVA, and VO2 from the control. The linear end-systolic pressure-volume relations and their slopes were virtually the same between the control and fentanyl volume loading in each heart. Further, either the slope (oxygen cost of PVA) or the VO2 intercept (unloaded VO2) of the linear VO2-PVA relationship remained unchanged by fentanyl. CONCLUSIONS: These results indicate that intracoronary fentanyl produces virtually no effects on LV mechanoenergetics for a wide range of its blood concentration.

Anesthetics, Intravenous↗

PubMed1997

Effects of intracoronary fentanyl on left ventricular mechanoenergetics in the excised cross-circulated canine heart (revised publication).

BACKGROUND: It is still unclear whether fentanyl directly alters left ventricular (LV) contractility and oxygen consumption. This is because of the difficulty in defining and evaluating contractility and energy use independently of ventricular loading conditions and heart rate in beating whole hearts. METHODS: This study was conducted to clarify the mechanoenergetic effects of intracoronary fentanyl in six excised cross-circulated canine hearts. The authors used the framework of the Emax (a contractility index)-PVA (systolic pressure-volume area, a measure of total mechanical energy)-VO2 (myocardial oxygen consumption per beat) relationship practically independent of ventricular loading conditions. The authors measured LV pressure, volume, coronary flow, and arteriovenous oxygen content difference to calculate Emax, PVA, and VO2. They first obtained the VO2-PVA relationship for varied LV volumes at control Emax. The authors then obtained the VO2-PVA relationship at a constant LV volume, whereas coronary blood fentanyl concentration was increased in steps up to 240 ng/ml. Finally, they obtained the VO2-PVA relationship for varied LV volumes at the final dose of fentanyl. RESULTS: Fentanyl at any concentrations did not significantly change Emax, PVA, and VO2 from the control. The linear end-systolic pressure-volume relations and their slopes were virtually the same between the control and fentanyl volume loading in each heart. Further, either the slope (oxygen cost of PVA) or the VO2 intercept (unloaded VO2) of the linear VO2-PVA relationship remained unchanged by fentanyl. CONCLUSIONS: These results indicate that intracoronary fentanyl produces virtually no effects on LV mechanoenergetics for a wide range of its blood concentration.

Anesthetics, Intravenous↗

PubMed1997

Hepatoprotective effect of Hovenia dulcis THUNB. on experimental liver injuries induced by carbon tetrachloride or D-galactosamine/lipopolysaccharide.

The hepatoprotective effects of the fruits of Hovenia dulcis THUNB. on chemically or immunologically induced experimental liver injury models were examined. The methanol extract showed significant hepatoprotective activity against CCl4-toxicity in rats and D-galactosamine (D-GalN)/lipopolysaccharide-induced liver injury in mice. The methanol extract also significantly protected against CCl4-toxicity in primary cultured rat hepatocytes. Hepatoprotective activity-guided fractionation and chemical analysis led to the isolation of an active constituent, (+)-ampelopsin (1) from the methanol extract.

Animals↗

PubMed1997

Application of PCR-RFLP and MASA analyses on 18S ribosomal RNA gene sequence for the identification of three Ginseng drugs.

In order to develop convenient and reproducible methods for the identification of Ginseng drugs at a DNA level, PCR-Restriction fragment length polymorphism (PCR-RFLP) and Mutant allele specific amplification (MASA) analyses were applied, based on differences of the 18S rRNA gene sequence among three Panax species. The PCR product of each species on the 18S rRNA gene was digested with the restriction enzymes Ban II and Dde I. Each fragment gave unique electrophoretic profiles for each species (PCR-RFLP analysis). The extracted DNA of each species was amplified by PCR using a designed species-specific oligonucleotide primer. The expected size of the fragments corresponding to each species were detected only when the optimum temperature and reaction time for annealing and extension were established (MASA analysis). These two analytical methods were carried out on three Ginseng drugs and the same results as in their original plants were obtained. The results suggest that PCR-RFLP and MASA analyses under the established conditions are convenient for identifying three Ginseng drugs. Moreover, to insure completion of the identification, a partial sequence of the plastid gene matK was determined in addition to the 18S rRNA gene. The gene sequences of three Panax species were of 1259 base pairs and that of P. quinquefolius was different from the other two at nucleotide position 102.

Panax↗

PubMed1997

Study on baths with crude drug. III. The effect of ligustici chuanxiong rhizoma extract on the percutaneous absorption of some natural compounds.

To investigate the permeability of natural compounds through hairless mouse skin, compounds having a range of lipophilicity, i.e., ginsenoside-Re (1), baicalein (2), glycyrrhizin (3), baicalein (4), wogonin (5), honokiol (6), magnolol (7), bergapten (8), shikonin (9) and sinomenine (10) were used. These compounds permeated through the skin a little, however, they were generally accumulated into the skin. The uptake amount into the skin of each compound related to their lipophilicities in the in vitro experiment. Furthermore, Ligustici Chuanxiong Rhizoma (Senkyu) ether extract (SEE) enhanced their permeability into the skin; especially, it exhibited an effect on the skin permeability of moderately lipophilic compounds such as 4, 8. The effect of SEE in vivo was similar to that obtained in the in vitro experiment. From these results, it was clarified that natural compounds having high lipophilicity sufficiently permeated into the hairless mouse skin owing to their accumulative property, and SEE enhanced the permeability of the moderately lipophilic compounds into the skin.

Animals↗