Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 73 records · Page 4Linked to original sources

PubMed1991

Isolation and monolayer culture of human fallopian tube epithelial cells.

In the present study we have established a pure monolayer culture system of human fallopian tube epithelial cells. The cells were isolated using collagenase digestion, and were cultured in Medium 199 supplemented with 15% fetal bovine serum. The epithelial cells derived from primary and secondary culture were characterized using immunocytochemical staining and electron microscopy. The cells continued to grow for 2 to 3 wk once the monolayer culture of the cells was established. It is currently possible to maintain the cultures until the third generation. Proliferation of these cells was enhanced by epidermal growth factor but not by basic-fibroblast growth factor, insulin, transferrin, estradiol-17 beta, or progesterone. This culture system offers a good model for determining characteristics of the tubal epithelium and would permit effective study of co-culture with embryos.

Adult↗

PubMed1991

Plasma levels of platelet-derived growth factor in normal subjects and patients with ischemic heart disease.

Plasma levels of platelet-derived growth factor (PDGF) were measured in 24 normal control subjects, 31 patients with stable angina pectoris, 25 patients with unstable angina pectoris, and 31 patients with acute myocardial infarction (AMI) by a sensitive direct radioimmunoassay. The plasma PDGF level in normal control subjects was 273 +/- 25 pg/ml; there was no significant correlation between the plasma PDGF level and age. Plasma PDGF levels in patients with unstable angina pectoris and acute myocardial infarction were significantly lower than those in normal control subjects and patients with stable angina pectoris (p less than 0.05). In patients with acute myocardial infarction the plasma PDGF level in the chronic phase was significantly higher than that in the acute phase (p less than 0.05). These observations raise the possibility that PDGF is involved in the pathophysiology of ischemic heart disease.

Adult↗

PubMed1991

Production of platelet-like particles by a human megakaryoblastic leukemia cell line (MEG-01).

The distribution of microtubules and platelet-specific glycoproteins (GPIIb/IIIa) in particles was probed by an immunofluorescence method using anti-tubulin and anti-GPIIb/IIIa antibodies to identify whether particles released from a human megakaryoblastic cell line (MEG-01) are platelets. The fluorescence image showing anti-tubulin staining of the particles revealed a characteristic ring structure observed in platelets. Anti-platelet GPIIb/IIIa antibody staining showed an image in which small patches or spots were seen throughout the particle with brighter staining at the periphery. No significant difference was observed between these particles and human blood platelets under immunofluorescent staining. These results show that MEG-01 cells released platelet-like particles.

Blood Platelets↗

PubMed1991

Role of capsaicin-sensitive afferent neurons in alkaline secretory response to luminal acid in the rat duodenum.

The role of capsaicin-sensitive afferent neurons in acid-induced HCO3- secretion was investigated in the duodenum of anesthetized rats. The proximal duodenum was perfused with saline (pH 4.5), the pH of perfusate and the transmucosal potential differences were continuously monitored, and HCO3- output was determined by pH change. Under these conditions, duodenal pH, potential difference, and HCO3- output were significantly increased in response to IV injection of prostaglandin E2 (300 micrograms/kg) and luminal acidification (10 mmol/L HCl, 10 minutes). These responses induced by luminal acid were significantly attenuated by SC pretreatment with indomethacin (5 mg/kg), preexposure of the mucosa to lidocaine (4%, 15 minutes), functional ablation of capsaicin-sensitive afferent neurons, or even prior application of capsaicin (6 mg/mL, 30 minutes) to the duodenum. Although capsaicin application by itself (0.3-6 mg/mL) produced a concentration-dependent increase of HCO3- output, this effect was significantly reduced by lidocaine, indomethacin, or chemical deafferentation and exhibited a tachyphylaxis after repeated application at a high concentration (6 mg/mL). Neither of these treatments significantly affected the HCO3- response induced by prostaglandin E2. It was concluded that stimulation of capsaicin-sensitive afferent neurons increased duodenal HCO3- secretion and that these neurons may be involved in the mechanism of HCO3- response induced by luminal acid in the duodenum.

Animals↗

PubMed1991

Circulating immunoreactive endothelin in patients undergoing percutaneous transluminal coronary angioplasty.

Circulating immunoreactive endothelin (ir-ET) in the coronary sinus (CS) and the femoral artery (Ao) was measured in patients who underwent percutaneous transluminal coronary angioplasty (PTCA). Plasma ir-ET level in the CS was significantly increased from 1.6 +/- 0.8 pg/mL to 2.0 +/- 1.0 pg/mL after PTCA (P less than .05). Plasma ir-ET level in the Ao tended to increase after PTCA, but it was not significant. Plasma ir-ET level in the CS was not related to the plasma thromboglobulin level, plasma thrombin-antithrombin complex level, mean blood pressure, or heart rate. These results suggest that the increase of plasma ir-ET level in the CS may be associated with the coronary endothelial injury by PTCA.

Adult↗

PubMed1991

Variations of nucleotide sequences and transcription of the SH gene among mumps virus strains.

We have compared nucleotide sequences of the SH genes as well as their flanking regions of six mumps virus strains and found a high amino acid diversity (up to 23%) of the putative SH proteins among these strains. It was found, in addition, that one of these strains (Enders strain) contained a point mutation in putative polyadenylation signal for the F gene mRNA (TTTAGAAAAAAA to TTTAGAAGAAAA). Northern blot analysis showed that the Enders strain was also unique in that neither monocistronic SH nor bicistronic SH-HN mRNA could be detected in the cells infected with this particular strain.

Animals↗

PubMed1991

An epidemiological study of brain tumours in the elderly.

An epidemiological study of brain tumours in elderly Japanese was undertaken on the basis of a report from the All Japan Brain Tumor Registry. Thus, the recent status of brain tumours in elderly Japanese could be clarified. Accordingly, the formerly compiled characteristics of brain tumours in the elderly should more or less be revised. However, we are all still facing the same unfavourable prognosis of brain tumours in the elderly as before.

Adolescent↗

PubMed1991

The particle size of hepatitis C virus estimated by filtration through microporous regenerated cellulose fibre.

To estimate the particle size of hepatitis C virus (HCV), a major causative agent of post-transfusion non-A, non-B hepatitis, we filtered plasma or serum samples through microporous cellulose fibres with different pore sizes. The amount of HCV particles in samples before and after filtration was determined by a quantitative reverse transcriptase polymerase chain reaction (PCR) method. Since there is no quantitative biological assay for HCV, except for that in chimpanzees, the HCV titre obtained from the PCR method was used in an equation constructed previously for application to filtration experiments with a flavivirus which is distantly related to HCV. The particle was estimated to be between 30 and 38 nm in diameter, although the possibility remained that larger HCV particles or HCV aggregates with a diameter of more than 39 nm might exist. Double-step filtration through microporous cellulose fibres with a pore size of 35 nm reduced the HCV content to below levels detectable by our PCR method, indicating that it is possible to eliminate HCV particles by simple filtration techniques.

Base Sequence↗

PubMed1991

Therapeutic effects of combined treatment using tetracycline-immobilized collagen film and root planing in periodontal furcation pockets.

46 upper and lower molars with furcation grade II involvement were selected from 16 patients with periodontal disease. The teeth were randomly allocated to the following groups according to treatment; (1) 4 consecutive administrations of tetracycline-immobilized cross-linked collagen film (TC film) at intervals of 1 week (TC group); (2) 1 root planing treatment (RP group); (3) combination treatment (TC + RP group); (4) no treatment (control group). The therapeutic effects of each treatment were compared both clinically and microbiologically. Records of plaque index, gingival index, bleeding on probing, probing depth, probing attachment level and microscopic counts were obtained at 0, 4, 6 and 8 weeks. The results showed marked decreases in probing depth and density of micro-organisms in both the RP and TC + RP groups. In particular, the TC + RP group was characterized by a decreased rate of bleeding on pocket probing and an increased probing attachment gain. The above findings demonstrated that root planning is effective in the treatment of furcation involvement and that the effects are enhanced by the local administration of TC films.

Collagen↗

PubMed1991

Discrimination of hepatitis C virus in liver tissues from different patients with hepatocellular carcinomas by direct nucleotide sequencing of amplified cDNA of the viral genome.

We investigated the presence of the hepatitis C virus (HCV) genome in liver tissues of eight different patients with hepatocellular carcinoma by using the reverse transcriptase polymerase chain reaction (PCR) method. RNA was extracted separately from cancerous and peripheral noncancerous portions of the liver tissues of each patient. For reverse transcriptase PCR, we used sets of primers derived either from nonstructural region 3 (the NS3 region) or from the nucleocapsid-envelope (C/E) region of the HCV genome. The nucleotide sequences of the amplimers were directly determined without subcloning. Of 16 samples tested, cDNA of the HCV genome was detected in 2 cancerous tissues and in 4 noncancerous tissues by either pair of primers. Nucleotide sequences of HCV cDNA fragments amplified from cancerous and peripheral noncancerous tissues from the same patients were identical. However, 4.4 to 6.3% and 7.5 to 11.3% sequence variation was observed in NS3 and C/E regions, respectively, among cDNA fragments from different patients. The result indicated that the HCV genome detected in a given patient is distinguishable from that in others by a simple direct nucleotide sequencing of the reverse transcriptase PCR products.

Base Sequence↗

PubMed1991

Expression of processed core protein of hepatitis C virus in mammalian cells.

A structural protein of hepatitis C virus (HCV) was expressed in monkey COS cells under the control of an exogenous promoter, and a protein of 22 kDa was identified by immunoblot analysis. This protein (p22), which was produced by processing in COS cells, reacted specifically to sera of chronic hepatitis C patients, and its coding region was mapped at the most amino-terminal part of the HCV polyprotein. These results suggested that the p22 protein is the nucleocapsid (core) protein of HCV. Moreover, the assay detecting antibody to p22 was found to be useful for early diagnosis of HCV infection.

Animals↗

PubMed1991

Malignancy associated with chronic empyema: radiologic assessment.

Radiologic findings of six cases of malignancy associated with chronic empyema 5-39 years in duration were reviewed. Pathologic examination confirmed three B-cell non-Hodgkin lymphomas, one round-cell sarcoma, one mesothelioma, and one adenocarcinoma. Retrospective findings on plain chest radiographs suggested the occurrence of malignancy: increased radiopacity in the thoracic cavity, soft-tissue bulgings and/or unsharpness of fat planes in the chest walls, destruction of bone near the empyema, and extensive medial deviation of the calcified pleurae. Computed tomography delineated masses with soft-tissue attenuation more clearly than radiography in all cases. Magnetic resonance images of three cases were informative because empyema cavities were surrounded by low-intensity rims, and two of them showed a signal intensity different from that of necrotic tumors. Scintigraphy revealed increased uptake of gallium in all cases. Ultrasonography was useful for biopsy guidance. Every radiologist should know this entity in observation of chest radiographs obtained in patients with chronic empyema, and further radiologic assessment and aggressive biopsy are recommended if malignancy is suspected.

Adenocarcinoma↗

PubMed1991

Oxygen free radicals and lipid peroxidation in the pathogenesis of gastric mucosal lesions induced by indomethacin in rats. Relation to gastric hypermotility.

The relationship of gastric hypermotility to mucosal hemodynamics, lipid peroxidation and vascular permeability changes was investigated in the pathogenesis of indomethacin-induced gastric lesions in rats. Subcutaneous administration of indomethacin (25 mg/kg) produced an increase in both the amplitude and frequency of stomach contraction from 30 min after treatment, resulting in hemorrhagic damage 2 h later. Gastric mucosal blood flow measured by a Laser flowmetry showed oscillatory fluctuations under hypercontractile states: a decrease during contraction followed by an increase during relaxation. Mucosal lipid peroxidation and vascular permeability were significantly increased with time after indomethacin treatment, and these changes preceded the appearance of hemorrhagic damage. All these events were prevented when gastric hypermotility was inhibited by atropine or 16,16-dimethyl prostaglandin E2. Pretreatment of the animals with allopurinol and hydroxyurea or continuous infusion of superoxide dismutase and dimethyl sulfoxide during a test period also attenuated these functional changes and mucosal lesions induced by indomethacin, without affecting the motility response. We conclude that oxygen free radicals may play a role in the development of mucosal lesions associated with gastric hypermotility in indomethacin-treated rats.

16,16-Dimethylprostaglandin E2↗

PubMed1991

Pheochromocytoma with electrocardiographic change mimicking angina pectoris, and cyclic change in direct arterial pressure--a case report.

A forty-two-year-old man was admitted because of chest pain. Electrocardiograms at admission showed horizontal ST depression in leads, II, III, aVF, V4, V5, and V6. Direct blood pressure monitoring revealed cyclic change between 160/100 mmHg and 70/50 mmHg and heart rate between 80/sec and 120/sec at fifteen minute intervals. The plasma norepinephrine and epinephrine concentrations were elevated during the episodes of hypertension. Pheochromocytoma was found in the right adrenal gland. These cyclic changes in blood pressure and heart rate are an aid for diagnosis.

Adrenal Gland Neoplasms↗

PubMed1991

Involvement of prostaglandin-producing pathway in the cytotoxic action of tumor necrosis factor.

To elucidate the cytotoxic mechanism of tumor necrosis factor (TNF), we isolated TNF-resistant sublines of L929 cells. As compared with L929 cells, TNF-resistant cells retained similar number and affinity of TNF-binding sites, and showed a similar growth rate. TNF stimulated arachidonate release from L929 cells, while no stimulation was observed at all in TNF-resistant cells tested. The cytotoxic action of TNF on L929 cells was inhibited by indomethacin, suggesting that prostaglandin may be involved in the action. Therefore, TNF-stimulated prostaglandin production was examined in L929 and TNF-resistant sublines. The amount of PGE2 produced by L929 cells was increased more than 5-fold after the addition of TNF, whereas the amount of PGE2 did not change in the resistant sublines following addition of the factor. TNF-stimulated arachidonate release and PGE2 production were reversed by islet-activating protein (IAP)-treatment of L929 cells. These results suggest that arachidonate release and subsequent prostaglandin production are important for the cytotoxic action of TNF and that these processes are mediated by GTP-binding protein (G protein) that is coupled to the TNF-receptor.

Animals↗

PubMed1991

Anticoagulant heparin-like glycosaminoglycans on endothelial cell surface.

Atherosclerosis is associated with an accumulation of proteoglycans. Proteoglycans and/or glycosaminoglycans, in particular heparan sulfate, produced by endothelial cells are thought to play important roles in diverse vascular functions. Of particular note is that they possess anticoagulant functions, i.e., heparin-like antithrombin cofactor activity. Incubation of antithrombin III with endothelial cell cultures resulted in a specific, saturable binding of this protease inhibitor presumably to the endothelial cell surface. In addition, thrombin inactivation by antithrombin III was accelerated on the endothelial surface, providing strong evidence that heparan sulfate on the surface of endothelial cells exerts a heparin-like activity. beta-D-xyloside or cytokine treatments altered the synthesis of heparan sulfate on the endothelial cell surface, resulting in decreased anti-thrombin III binding and diminished heparin-like anticoagulant activity of endothelial cells. The modulation of endothelial heparin-like compounds by these pharmacologic or physiologic agents may have pathophysiologic implications in thrombosis as well as atherogenesis.

Animals↗

PubMed1991

Assessment of superior vena caval blood flow velocity in ischemic heart disease.

In order to evaluate the right atrial function in patients with ischemic heart-disease, we studied the superior vena caval blood flow velocity using pulsed Doppler echocardiography. The subjects included 31 patients with anteroseptal infarction (ANT), 23 with inferior or inferoposterior infarction (INF + POS), 27 with effort angina pectoris (EAP) and 15 with vasospastic angina pectoris (VAP). The systolic peak flow velocity (PFVs) was significantly reduced only in INF + POS compared with those in ANT, EAP and VAP (36.8 +/- 1.8 cm/sec vs 46.9 +/- 2.1 cm/sec, 46.4 +/- 2.1 cm/sec and 42.6 +/- 1.9 cm/sec, p less than 0.05, respectively). No significant difference in diastolic peak flow velocity (PFVd) was found between the 4 groups. PFVs/PFVd was significantly reduced only in INF + POS compared with those in ANT, EAP, and VAP (1.39 +/- 0.05 vs. 1.75 +/- 0.08, 1.76 +/- 0.09, and 1.62 +/- 0.09, p less than 0.05, respectively). These results suggested that INF + POS caused impairment of the right atrial reservoir function.

Analysis of Variance↗

PubMed1991

[Healing promoting effect of azuletil sodium (KT1-32) on experimental chronic gastric ulcers and acceleration of healing in SPF environment].

We examined the healing promoting effects of azuletil sodium on acetic acid and clamping cortisone-induced gastric ulcer in rats. For the experiments on clamping-cortisone gastric ulcer, we used not only conventional rats in conventional conditions but also specific pathogen free (SPF) rats on SPF environment in order to prevent infection. The following results were obtained. 1) In acetic acid ulcer, azuletil sodium (AZE) (greater than or equal to 90 mg/kg/day, p.o.) significantly decreased ulcer index. As estimated on the basis of stage analysis (Ulcer, Healing, Scar), AZE (greater than or equal to 30 mg/kg/day, p.o.) significantly promoted the healing of ulcers. 2) In clamping cortisone ulcer (conventional), AZE (100 mg/kg/day, p.o.) significantly promoted the regeneration of blood vessels. 3) In clamping cortisone ulcer (SPF), AZE at greater than or equal to 30 mg/kg/day and 100 mg/kg/day significantly increased the healing index and mucosal regeneration index, respectively. 4) In clamping cortisone ulcer (SPF), the infection that was observed in the conventional test was not seen at all and the acceleration of healing was observed. Furthermore, the extent of adhesion was also reduced, and the standard errors of various healing indices were smaller. From these results, it is concluded that AZE accelerated the healing of experimentally-induced gastric ulcers in rats.

Animals↗