Search PubMed⌕ Search

Biomedical subjects

T Fujiwara

Publications and source records attributed to T Fujiwara.

At least 739 records · Page 41Linked to original sources
PubMed1993

Effects of high altitudes on finger cooling test in Japanese and Tibetans at Qinghai Plateau.

The influences of both hypobaric hypoxia and cold on peripheral circulation were studied using the finger cooling test (measurement of the decrease in finger temperature, measured at the dorsal surface of the finger, during immersion of the hand in 0 degrees C water for 20 min) at Qinghai Plateau. The same test was carried out at simulated altitudes in a 25 degrees C climatic chamber to separate the hypobaric hypoxia influence from that of cold. In Japanese subjects at Qinghai Plateau there was a significant difference between finger skin temperatures (FSTs) during 20 min of 0 degrees C water immersion at altitudes of 2260 m and 4860 m by ANOVA. Mean finger skin temperature during the 20-min immersion (5-20 min, MST) measured at 4860 m was significantly lower than that at 2260 m. In Tibetan subjects, there was also a significant difference between FSTs at 2260 m and at 4860 m by ANOVA. MST at 4860 m tended to be lower than that at 2260 m. In the 25 degrees C climatic chamber, there was a significant difference between FSTs of Japanese expedition members at 2000 m and at 4000 m by ANOVA. MST was higher at 4000 m than at 2000 m, contrary to the data obtained in Qinghai. In conclusion, the higher skin temperature in response to local cold immersion, which would have been caused by stronger hypobaric hypoxia, must have been masked by the lower ambient temperature.

Acclimatization↗
PubMed1993

Human T-cell leukemia virus type 1 protease protein expressed in Escherichia coli possesses aspartic proteinase activity.

We amplified the human T-cell leukemia virus type 1 (HTLV-1) protease gene fragment by polymerase chain reaction (PCR) and cloned it into a pUC plasmid vector. DNA sequencing data of the protease gene fragment indicated that it contained an open reading frame capable of encoding the active HTLV-1 protease. To express a fusion protein of beta-galactosidase linked with the HTLV-1 protease in Escherichia coli, a plasmid DNA was constructed by inserting the HTLV-1 protease gene DNA into a procaryotic expression vector, pUEX2, consisting of a lacZ gene directed by a lambda phage Pr promoter and designated pUEX-pro. By Western blot analysis using anti-beta-galactosidase antibody, a bigger molecular size band than that of the control beta-galactosidase molecule was observed in E. coli cells transformed with pUEX-pro but not with control pUEX2, suggesting that the particular fusion protein was successfully expressed. This recombinant protease protein in the E. coli cell lysate was demonstrated to be able to cleave the decapeptide substrates composed of amino acid sequences containing proteolytic cleavage sites in the HTLV-1 gag precursor polyprotein. The gag precursor polyprotein expressed in the mammalian cells by the recombinant vaccinia virus system was also expectedly cleaved by this enzyme. Significant inhibition of this protease activity by pepstatin A, an aspartic proteinase-specific inhibitor, confirms that HTLV-1 protease is a member of the aspartic proteinase group as suggested previously. Since the crude lysate without purification is utilized sufficiently as a native HTLV-1 protease reagent, this protease preparation is easily applicable to the large scale screening of HTLV-1 protease inhibitors for the treatment of diseases caused by HTLV-1.

Amino Acid Sequence↗
PubMed1993

Stable microbubble test for predicting the risk of respiratory distress syndrome: I. Comparisons with other predictors of fetal lung maturity in amniotic fluid.

With the advent of surfactant replacement therapy, there is an increasing need for a rapid test of predicting the development of respiratory distress syndrome (RDS). We evaluated the clinical usefulness of the stable microbubble (SM) test in predicting the development of RDS by comparison with other tests in amniotic fluid samples obtained within 12 h before delivery from 40 pregnancies between 23-35 weeks of gestation. These tests included the lecithin/sphingomyelin (L/S) ratio, disaturated phosphatidylcholine/sphingomyelin (DSPC/S) ratio, concentrations of lecithin, DSPC, and surfactant-associated proteins A and B, C (SP-A, SP-B,C). The cut-off value of each test for predicting RDS was determined at a point of maximum diagnostic accuracy. The overall diagnostic accuracy of the SM test was similar to that of other tests. However, both the SM test and the SP-B,C concentration had positive predictive values of 100%. We conclude that the rapid (< 10 min) and reliable information obtained by this test should encourage its use in defining a population of neonates with surfactant deficiency in a multicentre trial of prophylactic surfactant therapy.

Amniotic Fluid↗
PubMed1993

Stable microbubble test for predicting the risk of respiratory distress syndrome: II. Prospective evaluation of the test on amniotic fluid and gastric aspirate.

We determined prospectively if the stable microbubble (SM) test on gastric aspirate obtained at birth was as useful as that on amniotic fluid in predicting respiratory distress syndrome (RDS). One hundred and five paired samples of amniotic fluid obtained at delivery from 105 consecutive women with gestation of 35 weeks or less and gastric aspirates from their neonates obtained within 30 min of birth were studied. The SM test with the predefined cut-off value of less than 5 bubbles/mm2 for amniotic fluid and less than 10 bubbles/mm2 for gastric aspirate signified the risk of RDS with the positive predictive value of 100% and 96% and with the negative predictive value of 91% and 84%, respectively. We conclude that the SM test on both amniotic fluid and gastric aspirate obtained at birth is a rapid (< 10 min), simple and reliable procedure for predicting neonates who will develop RDS. It may be used as a bedside test to define a population of neonates with surfactant deficiency in clinical trials of prophylactic surfactant therapy.

Amniotic Fluid↗
PubMed1993

Sympathetic hyperinnervation protects vascular smooth muscle cells from necrosis in stroke-prone spontaneously hypertensive rats.

Sympathetic nerve fiber distribution and vascular smooth muscle morphology were investigated in the ophthalmic artery of stroke-prone spontaneously hypertensive rats (SHRSP) and were compared with those of normotensive Wistar Kyoto (WKY) rats at the age of 120 days. The distribution of fluorescent noradrenergic (NA) nerve fibers was examined by the glyoxylic acid method. The ophthalmic artery was divided into two portions according to the size of the outer diameter, that is into a proximal portion (above 100 microns) and a distal portion (30-70 microns). The distribution densities of noradrenergic nerve fibers were measured by quantitative image analysis using the Interactive Bild-Analyse System (IBAS). The distribution densities of NA nerve fibers in both portions of the ophthalmic artery were significantly higher (p < 0.01) in SHRSP than that in WKY rats. The difference in the density of NA fibers of the ophthalmic arteries between SHRSP and WKY rats was 1.9 times in the proximal portion and 1.5 times in the distal portion. The vascular smooth muscle cells of the ophthalmic arteries in SHRSP were observed by scanning electron microscope to examine the trophic effect of NA nerve fibers on the vascular smooth muscle cells. The smooth muscle cells of both portions of the ophthalmic arteries in SHRSP showed a smooth surface texture and no necrosis, and were very similar to those of WKY rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic Fibers↗
PubMed1993

Actin and myosin deposition around bile canaliculi: a predictor of clinical outcome in biliary atresia.

The role of pathological changes of the intrahepatic bile canaliculi in determining postportoenterostomy bile drainage in biliary atresia (BA) patients remains unestablished. It is known that canalicular contraction contributes an active force for bile flow in normal ductal systems. This motility is controlled by the bile canalicular membrane-associated filaments (BCMF), particularly actin and myosin. Wedge resected specimens of liver from 13 patients with BA were studied using histopathological markers of BCMF in order to clarify the morphological and functional changes of bile canaliculi. Histopathological data were also compared with clinical outcomes after portoenterostomy. Patients who showed sufficient bile flow after the operation showed an almost normal shape and level of BCMF accumulation around bile canaliculi, whereas there was markedly increased BCMF volume in patients who did not exhibit bile flow after surgery. The clinical staining patterns of BCMF in BA patients appears closely related to clinical outcome. These findings suggest that BCMF plays an important role in determining the rate of postoperative bile flow in BA patients.

Actins↗
PubMed1993

6-[18F]fluorodopa metabolism in patients with hemiparkinsonism studied by positron emission tomography.

A group of 10 healthy control subjects and 10 patients with hemiparkinsonism (HD) were studied by positron emission tomography (PET) using 6-[18F]fluorodopa (FDOPA). FDOPA metabolism in the caudate nucleus and the putamen was separately estimated by measuring target-to-background ratios (TBRs) using composite images added between 30 and 60 min after FDOPA injection and by TBR-versus-time slopes during PET study. TBRs in the caudate nucleus and the putamen were 1.81 +/- 0.23 (mean +/- SD) and 1.92 +/- 0.28 in the 10 controls, respectively. In HD patients, on the dominantly affected hemisphere related to main clinical symptoms, TBRs were significantly decreased in the caudate nucleus (P < 0.01) and the putamen (P < 0.05) compared with those in the corresponding areas on the contralateral hemisphere, though those TBRs on both hemispheres were significantly decreased compared with the TBRs of normal subjects (P < 0.01). TBRs and TBR slopes in both the caudate nucleus and the putamen were correlated with disease severity according to Hoehn and Yahr. On the dominantly affected hemisphere, TBR and TBR slopes in the putamen were well correlated with individual clinical measures for bradykinesia and rigidity, and those in the caudate nucleus were also correlated with the severity of tremor. Our data suggest that in HD patients, PET study using FDOPA may provide unique and efficient information on the dysfunction of the dominantly affected caudate nucleus and the putamen which are correlated with diseased severity and individual clinical symptoms.

Adult↗
PubMed1993

Antihypertensive effects of CS-045 treatment in obese Zucker rats.

The association of hypertension with obesity has been well recognized, but the etiology remains poorly understood. Obesity is characterized by hyperinsulinemia, which reflects peripheral insulin resistance. Insulin resistance may participate in the development of hypertension with obesity. CS-045 [(I)-5-[4-(5-hydroxy-2,5,7,8-tetramethylchroman-2-yl-methoxy)be nzy l]-2,4- thiazolidiendion] is a new orally effective antidiabetic agent that potentiates insulin action and reduces insulin resistance in obese Zucker rats and other obese diabetic animals. In this study, we examined the antihypertensive effect of CS-045 in obese male and female Zucker rats as a model of hypertension associated with obesity. CS-045 was administered as a food admixture (approximately 16 and approximately 70 mg/kg/d) for 4 weeks (female) and (approximately 15 and approximately 67 mg/kg/d) 8 weeks (male) in obese Zucker rats at 5 to 7 months of age. CS-045 slightly but significantly decreased plasma glucose levels. Plasma insulin levels were significantly decreased in obese male rats, but were not significantly decreased in obese female rats. Drug administration led to significant decreases in plasma triglyceride and cholesterol levels and systolic blood pressure (SBP) in a dose-dependent manner from 1 week after administration in obese Zucker rats. CS-045 increased urinary sodium excretion, sodium/potassium ratio, and creatine clearance in a dose-dependent manner, and also led to a remarkable decrease in urinary protein excretion. However, CS-045 did not reduce urinary catecholamine excretion. These data indicate that CS-045 may promote renal sodium excretion and improve decreased glomerular filtration rates, which may reflect the amelioration of insulin resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Stable expression of the wild-type p53 gene in human lung cancer cells after retrovirus-mediated gene transfer.

A retroviral vector-mediated system was established to allow efficient transduction of the wild-type p53 gene into human lung cancer cell lines H358a (deleted p53) and H322a (mutant p53). LNSX/p53 constructs incorporating p53 cDNA driven by a beta-actin promoter mediated stable integration of p53. p53 mRNA and protein were detected in these cell lines 6 months after transduction by Northern and Western blot analyses. Restoration of the wild-type p53 gene suppressed growth in the two transduced cell lines but had no effect in another transduced tumor cell line, H460a, which has an endogenous wild-type p53 gene. A high transduction efficiency was obtained in cell lines H460a, H322a, and H358a after five cycles of transduction in vitro. Mixing experiments showed that transduced cells could reduce the growth rate of nontransduced cells; this reduction may have been mediated by factors shed into the supernatant of the transduced cell cultures.

Base Sequence↗
PubMed1993

Velocity profiles and phasic flow patterns in the non-stenotic human left anterior descending coronary artery during cardiac surgery.

OBJECTIVE: The aim was to investigate the phasic characteristics of normal human left coronary artery flow and velocity profiles across the vessel. METHODS: The phasic characteristics of flow in the human left anterior descending coronary artery, the centreline flow velocities, and the velocity profiles were measured in 10 patients during corrective surgery for atrial septal defect after closure of the defect. None of these patients had any detectable coronary artery stenosis or left ventricular hypertrophy. Measurements were made with a 20 MHz 80 channel pulsed Doppler velocimeter. RESULTS: The velocity waveform displayed a diastolic-predominant pattern with a systolic to diastolic velocity ratio of 0.29(SD 0.17). Reverse flow was observed in early systole in five patients and in mid to late systole in six patients. The values of peak Reynolds number, unsteadiness parameter, and pulsatility index were 504(198), 2.5(0.6), and 5.9(4.4) respectively. The velocity profiles during diastole showed considerable variability in shape, ranging from symmetrical to skewed to M shaped patterns. The peak wall shear rate was 765(250) s-1 on the epicardial wall of the vessel and 712(301) s-1 on the myocardial wall; the difference was not statistically significant. CONCLUSIONS: The velocity waveform displayed a diastolic-predominant pattern. Considerable variability in shape of the velocity profile was found and was perhaps due to the time evolution of the velocity profile within the diastolic time period.

Adolescent↗
PubMed1993

Halobacterium halobium cytochrome b-558 and cytochrome b-562: purification and some properties.

Four different membrane-bound b-type cytochromes were found to occur in Halobacterium halobium strain L-33, and two of them, b-558 and b-562, were purified to homogeneity. Cytochrome b-558 showed absorption peaks at 414 and 526 nm in the oxidized form, and peaks at 425, 528, and 558 nm in the reduced form. Its alpha peak at 558 nm in the reduced form was asymmetric with a shoulder at around 554 nm. At liquid nitrogen temperature, the a the alpha peak was split into two peaks at 549 and 556 nm which appeared to be the alpha peaks of cytochromes c and b, respectively. The cytochrome contained 1 mol of protoheme in 28,500 g, and was composed of one molecule each of two subunits with molecular masses of 15.4 and 11.7 kDa, respectively. The heme seemed bound to the larger subunit. The cytochrome was very autoxidizable and its redox potential at pH 8.0 was -75 mV. Cytochrome b-562 showed absorption peaks at 417 and 530 nm in the oxidized form and peaks at 431, 531, and 562 nm in the reduced form. The cytochrome was composed of only one polypeptide (25 kDa) and seemed to contain one protoheme molecule per molecule.

Cell Membrane↗
PubMed1993

Alterations of vascular alpha 1-adrenergic contractile responses in hypercholesterolemic rabbit common carotid arteries.

In rabbits fed a diet containing 1% cholesterol and 4% lard for 4 or 8 weeks, vascular responses to alpha 1-adrenoceptor agonists, epinephrine (EPI), phenylephrine (PE), norepinephrine (NE), methoxamine (MO), and clonidine (CL) were examined in isolated common carotid arteries by the cannula-insertion method. The high cholesterol diet caused no microscopic evidence of atherosclerosis, and vasodilatory responses to ACh were well maintained, even in the 8-week group. Vasoconstrictions to EPI were augmented and those to NE, MO, and CL were progressively decreased, but that to PE was not influenced in 4- and 8-week-treated groups. These agonist-induced constrictions were readily inhibited by bunazosin and WB 4101, indicating that these result from alpha 1A-adrenoceptor activations. CL- and MO-induced constrictions were much more sensitive to WB 4101. Chlorethylclonidine (CEC) inhibited CL- and MO-induced constrictions, but not PE-induced, at relatively larger doses. We suggest that vasoconstrictivity to alpha-adrenoceptor agonists is altered by hypercholesterolemia without accompanying atherosclerotic changes and endothelial dysfunction, at the early stage of hypercholesterolemia, the sensitivity of alpha 1-adrenoceptors might be decreased at smooth muscle cell levels, and different changes in contractile reactivity to alpha 1-agonists after cholesterol feedings might be due to a decrease in alpha 1A-adrenoceptors.

Adrenergic alpha-Agonists↗
PubMed1993

Effects of selected surfactants on purified glucosyltransferases from mutans streptococci and cellular adherence to smooth surfaces.

The inhibitory effect of non-ionic, anionic, cationic and ampholytic surfactants on cellular growth of Streptococcus mutans MT8148 and S. sobrinus 6715, on glucan synthesis by the purified glucosyltransferase (GTase) from these organisms, and on bacterial adherence to glass surfaces was examined in vitro. Cationic surfactants exhibited marked bactericidal activities. Anionic and ampholytic compounds were less strongly bactericidal and non-ionic surfactants produced only slight inhibition of cell growth under the conditions tested. Some non-ionic compounds had no effect on this. Glucan synthesis by GTase from mutans streptococci was inhibited by anionic and cationic surfactants. Among various GTase proteins, insoluble glucan synthesising GTases, i.e., S. mutans CA-GTase and S. sobrinus GTase-I were those most effectively inhibited by these agents. However, it was noted that whereas lower concentrations of cationic surfactants enhanced these GTase activities, higher concentrations of the surfactants were inhibitory. Non-ionic detergents stimulated soluble glucan synthesis from S. mutans CF-GTase and cationic and ampholytic surfactants enhanced or inhibited glucan synthesis depending on the concentrations of the surfactants. Sucrose-dependent cellular adherence of resting cells of mutans streptococci to glass surfaces was inhibited by the addition of surfactants that annulled the GTase activities.

Bacterial Adhesion↗
PubMed1993

Drop attacks and epileptic syndromes.

1. In addition to 4 types of drop attacks previously described by Ikeno et al., we could ascertain the falls of the myoclonic-tonic type in genuine drop attacks. The genuine drop attacks were seen in Lennox-Gastaut syndrome, epilepsy with myoclonic-astatic seizures and other symptomatic generalized epilepsies, and never in partial epilepsies. 2. None of the patients with partial epilepsy revealed genuine drop attacks as defined. Their drop attacks were slower (i.e. the falls were completed in more than 1 sec.). 3. In the 15 patients with Lennox-Gastaut syndrome, the drop attacks disappeared in 8 patients, and decreased in severity and frequency in 3 patients. Namely, the intractability of drop attacks in two-thirds of the children decreased as the patients grew older. This finding must be taken into consideration when patients with drop attacks are considered for surgical treatment of their epilepsy.

Adolescent↗
PubMed1993

Oolong tea polyphenols inhibit experimental dental caries in SPF rats infected with mutans streptococci.

An extract of oolong tea (semifermented tea leaves of Camellia sinensis) and its chromatographically isolated polyphenolic compound was examined for in vitro inhibitory effects on glucosyltransferases (GTases) of mutans streptococci and on caries development in Sprague-Dawley rats infected with mutans streptococci. The samples showed no detectable effect on the growth of mutans streptococci. However, insoluble glucan synthesis from sucrose by the GTases of Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 was markedly inhibited, as was sucrose-dependent cell adherence of these mutans streptococci. The administration of the oolong tea extract and the isolated polyphenol compound into diet 2000 and drinking water resulted in significant reductions in caries development and plaque accumulation in the rats infected with mutans streptococci. The active components in the oolong tea extract were presumptively identified as polymeric polyphenols which were specific for oolong tea leaves. These results indicate that the oolong tea polyphenolic compounds could be useful for controlling dental caries.

Animals↗
PubMed1993

Ventricular expression of brain natriuretic peptide in hypertrophic cardiomyopathy.

BACKGROUND: Brain natriuretic peptide (BNP), as a cardiac hormone, is expressed together with atrial natriuretic peptide (ANP) in the ventricles in congestive heart failure. However, the ventricular expression of BNP in hypertrophic cardiomyopathy (HCM) with normal systolic function is still unclear. METHODS AND RESULTS: The study population consisted of 39 HCM patients with asymmetric septal hypertrophy and 10 control subjects without any specific cardiac disease. Eleven cases of HCM were obstructive (HOCM), and the other 28 cases were nonobstructive (HNCM). All of these patients had a normal ejection fraction. Immunohistochemical analysis of endomyocardial biopsy specimens with specific monoclonal antibodies showed BNP immunoreactivity in the HOCM group (5/10, 50%) but not in the HNCM group (0/22) or in control subjects (0/5). In HOCM, left ventricular end-diastolic pressure was significantly higher in the BNP-positive patients than the BNP-negative patients. Histological changes such as myocardial fiber disarray, hypertrophy of myocytes, and fibrosis were greater in BNP-positive patients than BNP-negative patients in HCM. However, the expression had no significant relation with other clinical parameters. The elevation of the BNP plasma level versus control subjects was marked in both HOCM (85-fold) and HNCM (23-fold). By contrast, the elevation of the ANP plasma level versus control subjects was mild in HOCM (5.7-fold) and HNCM (4.2-fold). The ratio of BNP level to ANP level was higher in HOCM (4.16) than in HNCM (1.46) and control subjects (0.28), and it was higher than the ratio previously reported for severe congestive heart failure (1.72). CONCLUSIONS: These findings suggest that BNP is expressed in the ventricular myocytes of HCM with normal systolic function. In HOCM, ventricular expression of BNP may be augmented in response to both obstruction and diastolic dysfunction.

Adult↗