Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 1,117 records · Page 62Linked to original sources

PubMed1991

Serum lipid and apolipoprotein levels in non-hypertensive lean NIDDM patients.

To determine the possible role of a glycaemic control in lipid metabolism in non-insulin-dependent diabetes mellitus (NIDDM) patients, serum lipid and apolipoprotein levels were measured in well-controlled and poorly controlled lean NIDDM without proteinuria and hypertension. A sample of 96 lean NIDDM patients (body mass index less than 25 kg m-2 in men and less than 27 kg m-2 in women) were divided into two groups: group I, where the HbA1c concentration had been less than 6% for the previous 3 months, and group II, where the HbA1c concentration had been greater than 8% for the previous 3 months. Serum total cholesterol, triglyceride, and HDL-cholesterol levels showed no significant differences between groups I and II. Furthermore, serum levels of apolipoproteins AI, AII, B, CII, CIII, and E did not differ significantly between groups I and II. These results suggest that glycaemic control did not influence lipid metabolism in lean NIDDM patients.

Adult↗

PubMed1991

The presence of anti-protein A antibodies in patients with rheumatoid arthritis.

Sixteen patients with rheumatoid arthritis (RA) were examined for the presence of anti-protein A antibodies. The F(ab')2 preparations from five RA patients showed significant binding to IgG-free protein A on ELISA. The protein A binding was further examined by immunoblotting. The F(ab')2 preparations of high protein A-binding protein gave a specific reaction with IgG-free protein A on nitrocellulose paper. This demonstrates the presence of anti-protein A antibodies in patients with RA. Those RA patients with anti-protein A antibodies had more active disease as judged by the Lansbury's activity index. The level of serum rheumatoid factor (RAHA) was significantly higher in patients with anti-protein A antibodies than in those without anti-protein A antibodies.

Adult↗

PubMed1991

Personality traits of patients with anxiety neurosis.

A total of 104 psychiatric outpatients diagnosed as anxiety neurosis according to Feighner's Diagnostic Criteria was investigated pre- and/or after illness by using a personality trait checklist designed for this study. The seven traits that appeared most frequently in patient clinical records were chosen for a further study: readily concerned; strong sense of responsibility; social; considerate; impatient; dependent; introspective. The investigation revealed that the frequencies of the "social" and "strong sense of responsibility" traits were conspicuously low, while the "dependent" trait was conspicuously high in the after illness trait profile compared to the premorbid profile. As for the premorbid personality traits and recoveries, the poor recovery group showed a relatively low "considerate" trait and a conspicuously high "impatient" trait profile.

Adolescent↗

PubMed1991

The differential contribution of endogenous prostaglandins to the release of acetylcholine from the myenteric plexus of the guinea-pig ileum.

1. Prostaglandin E (PGE) may be essential for maintaining the sensitivity of the myenteric plexus of guinea-pig ileum to nicotine. The contributions of prostaglandins to nervous activity evoked by different stimuli have now been investigated by measuring the amount of acetylcholine (ACh) released from the myenteric plexus of the guinea-pig ileum. 2. The amount of ACh released in response to dimethylphenylpiperazinium (DMPP) or substance P was depressed to about 40% of control by 2.8 microM indomethacin (Ind), whereas the release of ACh induced by 5-hydroxytryptamine (5-HT) was not affected. The inhibitory effects of Ind were overcome by 14.3 nM PGE2. 3. Mepacrine 5 microM, an inhibitor of phospholipase A2, depressed the release of ACh in response to DMPP and substance P to the same extent as Ind. These inhibitory effects of mepacrine were overcome by arachidonic acid (10 microM), but not by arachidonic acid plus Ind. The release of ACh evoked by 5-HT or electrical field stimulation (EFS) was also inhibited to about 60% of control by mepacrine but these inhibitions were overcome by arachidonic acid (10 microM) either in the absence or the presence of Ind. 4. The results suggest that endogenous prostaglandins and arachidonic acid contribute to the maintenance of the excitability of the myenteric plexus by DMPP and substance P. By contrast, the release of ACh induced by 5-HT and EFS may be regulated by arachidonic acid and not by prostaglandins.

Acetylcholine↗

PubMed1991

Differentiation of extracutaneous melanocytes in embryos of the turtle, Trionyx sinensis japonicus.

The present study investigates the mode of differentiation of neural crest-derived melanocytes in the embryos of the soft-shell turtle, Trionyx sinensis japonicus. DOPA reaction-positive melanoblasts were first detected in 10-day-old embryos. Melanocyte differentiation in terms of pigmentation takes place from the day 16 of development. Melanin pigments were found in the dorsal integument as well as in various extracutaneous tissues such as skeletal muscle, dorsal aorta, peritoneum, blood vessels, choroid, lung, bone marrow, fat tissues and in the connective tissue of the nose. These results suggest the presence of a specific environmental regulation of the melanoblast differentiation in the soft-shell turtle.

Animals↗

PubMed1991

Glucocorticoid stimulates melanogenesis and tyrosinase gene expression in B16 melanoma cells.

Effects of dexamethasone on melanogenesis and tyrosinase mRNA levels were determined in B16/F10 melanoma cells. Melanin content of B16 cells increased in a dose-dependent manner by the addition of dexamethasone to the culture medium. After 72 hr exposure, dexamethasone (10(-6) M) produced a 2.4-fold increase in melanin content. Northern blot analysis revealed that tyrosinase mRNA level also increased by the addition of dexamethasone to the culture medium. After 24 hr exposure, dexamethasone (10(-6) M) caused a 1.8-fold increase in tyrosinase mRNA levels. A tumor promoter, 12-O-tetradecanoyl phorbol-13-acetate (TPA) decreased tyrosinase mRNA level at 30 nM concentration. Dexamethasone antagonized this TPA-mediated decrease in tyrosinase mRNA. It is suggested that glucocorticoids are involved in the regulation of tyrosinase activity at the transcriptional level.

Animals↗

PubMed1991

Differences in genomic DNA sequences between pathogenic and nonpathogenic isolates of Entamoeba histolytica identified by polymerase chain reaction.

A lambda gt11 cDNA library was constructed from the poly(A)+ RNA of trophozoites of Entamoeba histolytica HM-1:IMSS strain. The library was immunologically screened with monoclonal antibody 4G6, which is specific for the 30,000-Mr antigen of pathogenic isolates. A 0.7-kb clone was isolated, and its nucleotide sequence was determined. To examine whether this gene was specific for pathogenic isolates, a polymerase chain reaction was performed by using four sets of primers and the genomic DNA of pathogenic and nonpathogenic isolates as templates. Amplified DNAs were detected not only in pathogenic isolates but also in nonpathogenic isolates. However, when sequences of amplified DNA of these isolates were compared, minor differences were observed. By considering the presence or absence of recognition sites of some endonucleases, it was possible to distinguish between the pathogenic and nonpathogenic isolates. When various isolates with different zymodemes were examined by polymerase chain reaction and enzyme digestion, the results of typing were entirely in accord with those of zymodeme analysis. These results indicate that there is dimorphism in the genomic DNA coding the 30,000-Mr antigen of E. histolytica and that the combined use of the polymerase chain reaction and enzyme digestion is a useful strategy for identification of species and determination of pathogenicity.

Amino Acid Sequence↗

PubMed1991

Effect of paeoniflorin, glycyrrhizin and glycyrrhetic acid on ovarian androgen production.

We have shown that traditional herbal medicine, Shakuyaku-Kanzo-To consisted of Shakuyaku and Kanzo decreased serum testosterone levels in woman and rat. Therefore, paeoniflorin and glycyrrhizin, a main component of Shakuyaku and Kanzo, respectively, and glycyrrhetic acid, a metabolite of glycyrrhizin in vivo, were investigated for the steroid production in the rat ovary on the morning of proestrus. The homogenized tissues of one ovary were incubated in the Dulbecco's modified Eagle medium (pH 7.5) with 100 micrograms/ml of paeoniflorin, glycyrrhetic acid and glycyrrhizin and the medium only (the control) at 37 degrees C for 270 min. After the centrifugation, the concentrations of delta 4-androstenedione, testosterone and estradiol in the supernatants were determined by RIA. The production of the hormones expressed by [concentration x supernatant volume/weight of the ovary] was compared to the control. Paeoniflorin, glycyrrhetic acid and glycyrrhizin decreased significantly the testosterone production but did not change that of delta 4-androstenedione and estradiol. Testosterone/delta 4-androstenedione production ratio was lowered significantly by paeoniflorin, glycyrrhetic acid and glycyrrhizin. Estradiol/testosterone production ratio was increased significantly by glycyrrhetic acid and not changed by paeoniflorin and glycyrrhizin. These results suggest that paeoniflorin, glycyrrhetic acid and glycyrrhizin affect the conversion between delta 4-androstenedione and testosterone to inhibit testosterone synthesis and stimulate the aromatase activity to promote estradiol synthesis by the direct action on the rat proestrous ovary.

Androgens↗

PubMed1991

Expression and processing of human preprogastrin in murine medullary thyroid carcinoma cells.

Gastrin, the primary hormonal mediator of postprandial gastric acid secretion, is produced from its precursor progastrin by a series of posttranslational processing reactions including dibasic residue cleavage and carboxyl-terminal alpha-amidation. Progastrin contains three dibasic cleavage signals, Arg57Arg58, Lys74Lys75, and Arg94Arg95, that appear to be cleaved differently in different tissues. Differential processing is a potential means by which the production of biologically active peptides may be regulated in a tissue-specific manner. To study these reactions further, we used the pZipNeo SV(X) retroviral vector to express human gastrin cDNA in a heterologous cell line (MTC 6-23) known to be capable of processing other peptide precursors. The psi 2 packaging cell line transfected with the gastrin cDNA-retroviral construct (pSVXgas) produced progastrin, but no substantial amounts of processed amidated gastrin were detected. amounts of processed amidated gastrin were detected. In contrast, MTC 6-23 cells infected with the viral stock obtained from the supernatant of pSVXgas-transfected psi 2 cells produced carboxyl-terminally amidated gastrin in all of its standard molecular forms, including sulfated and nonsulfated forms of tetratriacontagastrin (G-34), heptadecagastrin (G-17), and tetradecagastrin (G-14). These studies indicate that heterologous endocrine cell lines infected with a retroviral-peptide cDNA construct can serve as useful models for peptide hormone posttranslational processing.

Amino Acid Sequence↗

PubMed1991

Hepatic vascular exclusion as a model for complete and stable hepatic ischemia in dogs.

In order to confirm a complete ischemia model, 1-hour warm hepatic ischemia by hepatic vascular exclusion (HVE) was studied in dogs, in comparison with that by inflow occlusion (IOC) only. The splanchnic venous bed and/or infrahepatic inferior vena cava were decompressed by a centripetal pump-driven venovenous bypass. Indocyanine green retention test revealed no hepatic blood flow in the HVE model during ischemia, while hepatic blood perfusion was still present in the IOC model. All 5 of the IOC dogs survived more than 7 days after revascularization, while 4 of the 5 HVE dogs died within 9 h. After the induction of hepatic ischemia, lactate increased in both HVE and IOC dogs. After revascularization, transaminases and guanase were elevated, the arterial ketone body ratio (acetoacetate/3-hydroxybutyrate) decreased and the serum lactate accumulated more in HVE dogs than in IOC dogs. The hepatic redox state of IOC dogs was significantly decreased by additional clamping of the inferior vena cava. It is concluded that the HVE model with a pump-driven active bypass provides complete and stable hepatic ischemia, resulting in greater deterioration of hepatic cellular functions; hence it is more suitable as a model of complete hepatic ischemia than the IOC one.

Animals↗

PubMed1991

Temporary portal vein arterialization as an attractive option in canine orthotopic partial liver transplantation.

We performed 22 canine orthotopic partial liver transplantations (PLTs) with three different revascularization methods; portal vein arterialization (PVA group, n = 11), hepatic arterial shunt (HAS group, n = 5), and conventional portal vein reperfusion (control group, n = 6). Our purpose was to evaluate the feasibility of PVA as a revascularization technique in PLT assessing the changes in arterial ketone body ratio (KBR) as an index of hepatic energy status. After the first anastomosis (left hepatic vein), the ischemic partial liver graft was revascularized with arterial blood flow shunted from the external iliac artery to the hepatic side of the portal vein (PVA group) or the proper hepatic artery (HAS group). Both anhepatic period and ischemia time were significantly shortened in groups PVA and HAS as compared with those in control. In the PVA group, 10 out of 11 recipients survived for at least 5 days (14.2 +/- 3.8 days, mean +/- SEM), while 3 out of 5 (5.2 +/- 1.0) survived in the HAS group and 4 out of 6 (6.2 +/- 1.3) in the controls. Although portal blood flow during PVA was only about 25% of the total hepatic blood flow at preclamping, the KBR was rapidly restored after PVA and showed almost the same values at preclamping. The KBR values during the arterialization time and initial velocity of KBR recovery in the PVA group were significantly higher than those in the HAS and control groups. These results suggest that PVA presents an attractive option in PLT.

Animals↗

PubMed1991

Complement function and the synthesis of lung surfactant may be a regulation which preterm infants have in common.

The levels of CH50, the complement components, C1q, C4, and C3, C3 degradation fragments, and factor B were determined in the cord blood of 128 newborn infants. The levels of C3, C4, and C3d3 (an index of chronic in vivo complement activation) were clearly lower in the 28 infants with respiratory distress syndrome (RDS) than in the infants with other lung diseases or with normal lungs. CH50 and factor B levels were also low in RDS. Levels of C1q and other serum components in RDS infants were similar to the average levels in other infants without RDS at a corresponding gestational age. Lung surfactant is synthesized in alveolar type 2 cells, in which the complement components C4, C3, and factor B, but not C1q, have been reported to be synthesized. It seems possible that common factors regulate the synthesis of some complement components and surfactant.

Complement C1q↗

PubMed1991

Esterase-like activity of human serum albumin. VII. Reaction with p-nitrophenyl 4-guanidino-benzoate.

The reaction of p-nitrophenyl 4-guanidinobenzoate (NPGB) with human serum albumin (HSA) was examined kinetically at various pH's and 25 degrees C. The Michaelis constant (Ks in M) and the catalytic rate constant (k2 in s-1) were determined. The ratio of k2 to k0 (hydrolysis rate constant of NPGB in s-1) at pH 7.4 was 75.6, indicating the esterase-like activity of HSA. The effects of the reversible binding of site-specific drugs and the chemical modification by site-specific reagents on the HSA activity indicated that HSA has multiple reactive sites towards NPGB. Results of the reaction in the presence of excess NPGB over HSA also suggested the existence of multiple active sites. The pH-profile for k2 showed inflection points at about pH 6.0 and pH 10.0, suggesting the involvement of groups with pKa's of 6.0 and 10.0 in HSA.

Benzoates↗

PubMed1991

Effects of MCI-727, a new anti-ulcer agent, on plasma secretin concentration in rats and dogs and pancreatic exocrine secretion in rats.

In the present study, we investigated the effects of MCI-727, a new anti-ulcer agent, on plasma immunoreactive secretin concentration in rats and dogs using secretin specific RIA with the ethanol extraction method. Plasma secretin levels were increased dose-dependently 10 min after oral administration of MCI-727 in rats (control: 5.5 +/- 0.6; MCI-727, 10 mg/kg: 10.4 +/- 2.6; 30 mg/kg: 15.3 +/- 1.5; 100 mg/kg: 20.7 +/- 2.6 pg/ml, n = 6). Teprenone also caused a significant increase of plasma secretin at 10 min after oral administration at the doses of 30, 100 and 300 mg/kg. Under the same conditions, MCI-727 and teprenone did not alter the plasma immunoreactive gastrin concentration in rats. From the results of the time course study, the increasing effect of MCI-727 (30 mg/kg, p.o.) on plasma secretin remained for at least 240 min after administration. On the other hand, the increasing effect of teprenone (200 mg/kg, p.o.) was only observed at 30 and 60 min after administration. Furthermore, MCI-727 had increasing effects on plasma secretin concentration in dogs, but teprenone had no effects in this species. The volume of pancreatic secretion and the pancreatic bicarbonate output increased after intra-duodenal administration of MCI-727 at 30 and 100 mg/kg in rats. Similar effects were also observed with teprenone (30-300 mg/kg, i.d.) or secretin (Secrepan, 0.1-1.0 unit/kg, i.v.).

Administration, Oral↗

PubMed1991

Visual evoked potential from scalp in guinea pigs.

Visual evoked potentials (VEPs) recorded from the scalp in guinea pigs were compared with those from the dura. The study was performed with ten adult male guinea pigs weighing 350-750 g. VEPs recorded from the scalp had large negative components (N40 and N75) and a large positive component (P55). The waveform of the VEP in the scalp recording was similar to that in the dural recording in that N40 was a major early negative component. Great differences between the scalp and the dural recording were observed in the late negative components (N75 and N140). In the dural recording, the peak N75 was a very small component, and the peak N140 was very large. There was no significant difference between the peak latencies of the two kinds of VEPs except for the peaks P55 and P100. Peak-to-peak amplitudes of VEPs recorded from the scalp were smaller than those from the dura except for P55-N75. The peak-to-peak amplitude in the scalp recording compared to that in the dural recording varied from a ratio as low as 1.0:2.9 to as high as 1.0:36.2, and was markedly variable in each component. The scalp recording correlated with the dural recording as regards the early component.

Animals↗

PubMed1991

Changes in the visual evoked potentials with different photic conditions in guinea pigs.

Visual evoked potential (VEP) was studied in five adult male guinea pigs weighing 350-750 g. VEPs were recorded with chronically implanted electrodes. Photic stimulation was presented in the following order: binocular, left eye, right eye, and screened binocular. The averages of the responses were made from 140 samples. When a single eye was exposed to photic stimulation, the ipsilateral VEP was different from the contralateral VEP; the peaks N140 and P200 disappeared, and the peak latencies of N75 and P100 were significantly (P less than 0.05) longer than those in the contralateral hemisphere. Peak-to-peak amplitude N40-P55 in the ipsilateral VEP was significantly (P less than 0.05) lower than that in the contralateral VEP. The contralateral VEP by monocular stimulation was generally indistinguishable from the response to binocular stimulation. As described above, when only a single eye was exposed to flashes, the ipsilateral dural VEP was different from the contralateral dural VEP.

Animals↗

PubMed1991

Effect of cell density on growth hormone release from, cyclic AMP levels in and peptide alpha-amidation activity of primary cultured rat anterior pituitary cells.

To investigate the effect of cell density on rat somatotrophs, dispersed adult rat anterior pituitary cells were plated at several densities (0.6, 1.2, 2.4 and 6.0 x 10(5) cells/cm2) or at two densities (6.07 x 10(5) and 1.21 x 10(5) cells/cm2) as high and low densities respectively. A static incubation system was used to study the release of GH and peptidyl glycine alpha-amidating enzyme (PAM; a component of secretory granules) and the cellular concentration of cyclic AMP (cAMP) in basal and stimulated cells. In addition, a perifusion system was used to characterize the sensitivity to GH-releasing factor (GRF) at both high and low densities. The high density of cells in both the static incubation and perifusion systems caused a low basal secretion rate of GH and PAM. When the cultured cells were stimulated with human GRF (hGRF) in perifusion, GH secretion from cells at high density was markedly higher than that from cells at low density. The cAMP content in the static incubation system showed a similar tendency to that observed for basal and stimulated GH secretion; that is, the basal cAMP content was increased as the cell density decreased. The cellular concentration of cAMP was increased by about threefold by 1 nmol hGFR/l and by more than tenfold by 10 nmol hGRF/l. When the medium from cells cultured at low density was replaced by that from the cells at high density, there was no change in the basal cellular cAMP content of the cells at low density.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Aneurysm in the horizontal segment of the anterior cerebral artery confirmed by cerebral vasospasm--case report.

A rare aneurysm in the horizontal segment (A1) of the right anterior cerebral artery was found in a 58-year-old male presenting with subarachnoid hemorrhage. No obvious bleeding source was observed on the day of onset, but 7 days later, a definite diagnosis was made based on the discovery of cerebral vasospasm by a repeat angiogram. The aneurysm was clipped via the right frontotemporal approach 15 days after onset. He suddenly developed neurological symptoms such as consciousness disturbance, right hemiplegia, and aphasia on the 4th postoperative day, when remission of the cerebral vasospasm was confirmed by transcranial Doppler ultrasound examinations and cerebral angiography. The ischemic symptoms were probably due to cerebral embolus caused by intraluminal thrombi, which had formed during the maximum phase of vasospasm and became detached during the remission phase.

Cerebral Angiography↗