Biomedical subjects

H Shibata

Publications and source records attributed to H Shibata.

At least 523 records · Page 29Linked to original sources

PubMed1989

Cis- and trans-acting factors for transcription of the adenovirus 12 E1A gene.

Cis- and trans-acting factors were analyzed for transcription of the adenovirus 12 E1A gene possessing two sites for transcription initiation. These sites are located at nucleotide positions 306 and 445 with respect to the left end of the viral genome as position 1. The template activity of DNAs with various deletions at the 5'-upstream region of the E1A gene was examined in a cell-free system using a nuclear extract of Ehrlich ascites tumor cells. A DNA region specifically stimulating transcription initiated at the site distal to the E1A coding sequence was found located between positions 1 and 166. No DNA sequence affecting transcription from a proximal start-site appeared to be present in the region between positions 1 and 378. DNaseI-footprinting indicated that factors present in the extract bind to two distinct DNA segments, both of which are located within a region stimulating distal transcription. Two footprints were observed, one between positions 19 and 55 and the other between 77 and 94. The former footprint was inhibited by synthetic oligonucleotides containing a sequence recognized by nuclear factor I and the latter contained a sequence similar to one present in the B-enhancer of polyoma virus. Competition of in vitro transcription with synthetic oligonucleotides indicated (a) nuclear factor(s) bound to the region between positions 19 and 55 to be responsible for stimulating distal transcription of the adenovirus 12 E1A gene.

Adenovirus Early Proteins↗

PubMed1989

Interactions of factors bound at two different sites in the 5'-upstream region of the adenovirus 12 E1A gene.

A nuclear extract of Ehrlich ascites tumor cell contains factors binding to two distinct sites in the 5'-upstream region of the adenovirus 12 E1A gene. The gel shift assay was performed for characterization of the binding factors with oligo DNA probes containing sequences corresponding to these sites. The specific binding of a factor to one probe was enhanced when the other oligo DNA was present in excess in the binding reaction. Thus possibly, protein-protein interactions between factors may mutually prevent their binding to target sequences.

Adenoviridae↗

PubMed1989

3,4-Dinitrophenyl N-acetyl-beta-D-glucosaminide, a synthetic substrate for direct spectrophotometric assay of N-acetyl-beta-D-glucosaminidase or N-acetyl-beta-D-hexosaminidase.

3,4-Dinitrophenyl N-acetyl-beta-D-glucosaminide (3,4-dnpGlcNAc) was synthesized and proposed as an artificial substrate for N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) and N-acetyl-beta-D-hexosaminidase (EC 3.2.1.52) (collectively abbreviated as NAGase). 3,4-dnpGlcNAc is water soluble and is fairly stable in aqueous medium. 3,4-Dinitrophenol released from 3,4-dnpGlcNAc by NAGase absorbs light of 400 nm at pH near 5, where the activity of urinary NAGase is assayed for diagnostic use. Direct and sensitive spectrophotometric assay of NAGase is, thus, possible using 3,4-dnpGlcNAc as an artificial substrate by monitoring the increase of A400 due to the release of 3,4-dinitrophenol in a thermostated spectrophotometer.

Acetylglucosamine↗

PubMed1989

Further studies on a chemoattractant derived from Aleurites Fordii Hemsl. seed.

1. Activities stimulatory to PMN superoxide generation and chemotactic function were present in two separate gel chromatographic fractions of AFH-S and were designated AFH-S1 (500 kD) and AFH-S2 (38 kD). 2. Characterization studies of these activities revealed physiologic and pharmacologic characteristics dissimilar to those of other previously studied chemoattractants such as bacterial peptide FMLP.

Calcium↗

PubMed1989

The effect of aging on the electrocardiographic findings in the elderly--a 10-year longitudinal study: the Koganei Study.

To investigate the effect of aging on the electrocardiographic findings in the elderly, we analyzed the changes of the electrocardiographic findings according to the Minnesota Code in a 10-year longitudinal study. The aging effect on the electrocardiographic findings was expressed in the increase of Q-QS patterns and ST depression in both sexes, T-wave changes in males and QRS axis deviation in females. Prevalence of high amplitude R waves in both sexes, QRS axis deviation, atrioventricular conduction defects, intraventricular conduction defects and arrhythmias in males and T-wave changes in females also tended to increase with aging. Over the 10-year observation period, only high amplitude R waves, atrioventricular conduction defects and arrhythmias had a tendency to occur more frequently for both sexes in the hypertensives than in the normotensives. However, there was no significant difference in incidence between them. These facts suggest that, in the elderly, the age itself is important in ECG changes with aging.

Age Factors↗

PubMed1989

ACTH-induced seizures in an infant with West syndrome.

We report seizures induced by adrenocorticotropic hormone (ACTH), which were demonstrated clinically and electro-encephalographically, in a severely handicapped 7-month-old infant with West syndrome due to perinatal hypoxicischemic encephalopathy. Although tonic spasms (original seizures) decreased soon after starting ACTH treatment, new brief tonic seizures, somewhat more slowly motioned than the original tonic spasms, frequently appeared only during sleep after consecutive ACTH injections for 11 days, in place of the tonic spasms seen in the waking state. After discontinuation of ACTH therapy with the last injection on the 16th day, the brief tonic seizures began to decrease and finally disappeared in 8 days. Ictal EEG of new brief tonic seizures revealed diffuse fast spiky wave bursts, 50-150 microV and 10-20 c/s, with a duration of 0.5-4 seconds, which were different from attenuation associated with low voltage rhythmic fast activity corresponding to tonic spasms, the original seizures. Therefore, we considered that the new brief tonic seizures, which appeared only during sleep in the course of ACTH therapy, were ACTH-induced seizures.

Adrenocorticotropic Hormone↗

PubMed1989

Mortality in relation to instrumental activities of daily living: one-year follow-up in a Japanese urban community.

One-year mortality among 7,573 elderly residents living in an urban Japanese community was observed in relation to disability in instrumental activities of daily living (IADL). Disability in IADL was assessed for seven items of activity, including using public transportation, using the telephone, and shopping. When the effects of age were controlled, the mortality rate was significantly higher in disabled than in nondisabled persons for all seven items for both males and females.

Activities of Daily Living↗

PubMed1989

Evaluation of fluorescence polarization immunoassay for determination of cyclosporin in plasma.

The fluorescence polarization immunoassay (FPIA) method for determination of cyclosporin in plasma was evaluated and compared with the high-performance liquid chromatography (HPLC) and the radioimmunoassay (RIA) methods. The coefficients of variation for the within-run and between-run precision were less than 5 and less than 8%, respectively, for samples ranging in concentration from 50 to 600 ng/ml. Recoveries were determined by adding cyclosporin at concentrations from 25 to 1,000 ng/ml to patient plasma; they were, on average, 98.5%. The calibration curve was stable throughout a 10-week study period. There was no clinically significant interference due to hemolysis, icterus, lipemia, or other commonly used drugs. There was considerable variation of the ratio of the FPIA result to the HPLC result, whereas there was a good correlation between the FPIA and the RIA results (r = 0.975, n = 25, y = 1.2x - 36.4), when evaluated using specimens from renal transplant patients receiving cyclosporin orally. It was concluded that the FPIA is an appropriate, rapid method for patient cyclosporin analysis in plasma and serves as a practical alternative to the RIA.

Adolescent↗

PubMed1989

Assessment of cardiopulmonary baroreflex function in hypertensive and normotensive subjects with or without hypertensive relatives.

1. To investigate whether cardiopulmonary baroreflex control contributes to the pathogenesis and progression of hypertension, we have evaluated the function of the cardiopulmonary baroreflex in 22 patients with essential hypertension and in 17 volunteers with normotension. The normotensive group consisted of 8 subjects with a family history of hypertension and nine with no family history. 2. Forearm vascular resistance (FVR) and central venous pressure (CVP) were measured under control conditions when -10 mmHg lower body negative pressure was applied; the cardiopulmonary slope (CPS = delta FVR/delta CVP) was calculated as an index of the cardiopulmonary baroreflex function. 3. CPS was significantly higher in hypertensives (6.0 +/- 3.93 [s.d.], P less than 0.01) and also tended to be higher in normotensives with a family history of hypertension (3.9 +/- 3.53, P less than 0.05), compared with normotensives without a family history of hypertension (1.7 +/- 0.88). 4. When the hypertensives were divided into two groups, depending on whether CPS was greater or less than 6.0 units, cardiac wall thickness (20 +/- 1.6 mm vs 23 +/- 3.2 mm, P less than 0.05) and the renal vascular resistance (20.9 +/- 6.52 units vs 28.9 +/- 7.32 units, P less than 0.05) were both significantly higher in the Low CPS group. 5. These findings suggest that cardiopulmonary baroreflex function was augmented even in normotensive subjects with hypertensive relatives, as compared with those without hypertensive subjects. Furthermore, cardiopulmonary baroreflex function was augmented in the early stages of hypertension and diminished further with increasing severity.

Adult↗

PubMed1989

The pharmacokinetics and pharmacodynamics of a new thromboxane synthetase inhibitor, 6-(1-imidazolylmethyl)-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid (DP-1904), in man after single oral administration.

The pharmacokinetics of DP-1904, a new potent and selective thromboxane synthetase inhibitor and its effects on ex-vivo prostanoid formation were studied in Japanese normal male volunteers, who received orally a single 10, 20, 50, 100, 200, 400 or 800 mg dose. The drug was well tolerated by all subjects without evidence of any adverse reactions. The absorption of DP-1904 from gastro-intestinal tract was rapid. After oral doses of 10-800 mg of the drug given to volunteers in the fasted state, the mean maximum drug concentrations in plasma (Cmax) (mean +/- s.e., n = 5) of 0.215 (+/- 0.041), 0.399 (+/- 0.037), 1.47 (+/- 0.22), 2.86 (+/- 0.22), 4.66 (+/- 0.58), 7.28 (+/- 0.72) and 16.9 (+/- 2.6) micrograms mL-1 were reached within 1 h. DP-1904 concentrations declined monophasically after Cmax with half lives of 30-40 min. These half lives were independent of the administered doses. The mean area under the concentration-time curves (AUCs) increased from 0.398 (+/- 0.038) to 30.0 (+/- 2.7) micrograms h mL-1 as the dose increased from 10 to 800 mg. Linear relations between the doses and Cmax and AUCs were observed. The correlation coefficients for Cmax and AUC were 0.930 and 0.960, respectively. The apparent oral clearance (CL/F) and renal clearance (CLR) did not change significantly as dose increased from 10 to 800 mg. The kinetics of DP-1904 proved to be linear in the dose range studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1989

Cold exposure reverses inhibitory effects of fasting on peripheral glucose uptake in rats.

The effects of fasting and cold exposure on glucose uptake in skeletal muscles (tibialis anterior, quadriceps, and soleus), heart, and brown adipose tissue (BAT) were studied in conscious rats. Glucose uptake was estimated by determining the glucose metabolic index of individual tissues using the 2-[3H]deoxyglucose method. Fasting for 18 h at 25 degrees C decreased plasma glucose levels (-40%) and glucose uptake in heart (-95%) and skeletal muscles (-64-90%) but did not significantly affect glucose uptake in BAT. Fasting for 48 h did not further decrease these parameters. On the other hand, cold exposure (48 h at 5 degrees C) of fed animals did not alter plasma glucose levels but increased glucose uptake in heart (73%), skeletal muscles (126-326%), and particularly in BAT (95-fold). Remarkably, cold exposure stimulated glucose uptake in BAT and skeletal muscles of 18-h fasted rats by the same order of magnitude as in fed animals (percentagewise), thereby indicating that glucose represents an essential metabolite for shivering (muscles) and nonshivering (BAT) thermogeneses. In the heart of starved animals, the cold-induced increase in glucose uptake was even more important (8-fold) than in fed animals. Considering that cold exposure of fasted rats results in a severe insulinopenia, it is suggested that cold exposure stimulates glucose uptake in peripheral tissues primarily by enhancing glucose oxidation via insulin-independent pathways.

Adipose Tissue, Brown↗

PubMed1989

Arterial infusion of combination therapy using dibutyryl adenosine 3',5'-monophosphate and mitomycin C for hepatocellular carcinoma occluding main portal vein: case studies.

Intraarterial infusion therapy combining dibutyryl adenosine 3',5'-monophosphate and mitomycin C was administered to 8 patients with hepatocellular carcinoma occluding the main portal vein. Three patients survived more than nine months, including 1 who has been well for forty-eight months with technical imaging showing complete regression. A decreased level of serum alpha-fetoprotein of more than 90% was obtained in 38% of patients. Causes of death included hepatic failure, rupture of esophageal varices, acute gastric ulcer, and cerebral hemorrhage. It is concluded that the combination therapy may be useful for HCC.

Adult↗

PubMed1989

Effects of temperature and endogenous factors in blood on concentrations of cyclosporin in plasma measured by high-performance liquid chromatography.

The effects of temperature, hematocrit (Hct), lipid level in plasma and cyclosporin A (CyA) level in whole blood on the concentration of CyA in plasma measured by high-performance liquid chromatography were studied in vitro. With rise in blood storage temperature before cells were removed, the concentration of CyA in plasma was increased in the temperature range between 10 degrees C and 37 degrees C, but was decreased between 4 degrees C and 10 degrees C. With rise in Hct, the concentration of CyA in plasma was decreased, and it was more markedly decreased at the blood storage temperature of 4 degrees C than at 37 degrees C. A lipid supplementation study showed that the concentration of CyA in plasma was increased with rise in plasma triglyceride level and in plasma cholesterol level at the storage temperature of 4 degrees C but not at 37 degrees C. Studies of the effect of CyA concentration in blood on the CyA distribution in blood demonstrated that the cellular/plasma concentration (C/P) ratio at low levels (less than 200 micrograms/ml) of plasma CyA ranged from 4 to 10 and was about 2 times higher than that at higher concentrations at 4 degrees C, but the ratio was relatively constant at 37 degrees C. The saturation capacity of the cellular fraction for CyA showed considerable individual variations, but there was no difference between the capacities at 4 degrees C and 37 degrees C. The separation of plasma after equilibration at 37 degrees C made it possible to avoid the variations in the distribution of CyA in whole blood associated with changes in Hct, lipid level in plasma and CyA level in whole blood, and to obtain a measurement reflecting the physiologically significant concentration of CyA in plasma.

Chromatography, High Pressure Liquid↗

PubMed1989

[Biological characteristics of plasmid carrying a repeated deoxyribonucleic acid sequence].

It was found that a plasmid which had a foreign deoxyribonucleic acid (DNA) between two repeated sequences did not multiply in E. coli recBCsbcB, even if it multiplied in wild-type E. coli, E. coli recBC or E. coli recBCsbcBrecF when the insert was longer than 351 base pair. The multiplication of these plasmids were, however, inhibited when a plasmid expressing recF gene was introduced into E. coli recBCsbcBrecF. The inviability of the plasmid carrying the repeated sequence in E. coli recBCsbcB was discussed by the mechanism of recombination, and the functions of recF, recBC and sbcB were speculated. When E. coli recBC was transformed with pDR1 which was a derivative of pBR322 carrying a directly repeated sequence between which a DNA fragment derived from plasmid R6K with its origin was inserted, the intramolecular recombinant appeared. The recombinant recovered was, however, only the plasmid which had the replication origin of pBR322. The result suggests that pBR322 is compatible with pDR1 but R6K is not. The replication origin of R6K seems to be preferrentially used by pDR1.

DNA, Bacterial↗

PubMed1989

[In vitro replication of plasmid pKYM].

The crude extract (fraction II) prepared from E. coli could replicate plasmid pKYM, only when the extract contained the rep protein which was produced by the plasmid and essential for its multiplication in vivo. The intermediate of replication was accumulated when a dideoxynucleotide triphosphate was added to the reaction mixture. By analyzing the intermediate, the initiation site of the deoxyribonucleic acid replication and the direction of replication could be determined. The replication initiated inside the ori region of pKYM and the direction was unidirectional. The analysis also suggested that the synthesis of the lagging strand stopped at almost the same site as the initiation site.

Adenosine Triphosphatases↗

PubMed1989

Effect of D-galactosamine on blood clearance of 99mTc-phytate in rats.

The effect of D-galactosamine (GalN) on the blood clearance of 99mTc-phytate (99mTc-P) in rats was examined, and the blood clearance test of 99mTc-P was compared with the cases of serum transaminase and bilirubin test. Serum transaminase and bilirubin levels in rats increased dose-dependantly after GalN administration. The disappearance rate of 99mTc-P from blood decreased with the increase in dose of GalN and with the passage of time after the GalN administration. Changes of the blood clearance of 99mTc-P after GalN treatment in rats may be influenced by the disorder in the hepatocytes and the alteration of the liver reticuloendothelial system phagocytic function. The blood clearance test of 99mTc-P in rats showed a sensitive reaction for the acute hepatic dysfunction induced by GalN equally to or higher than the serum transaminase and bilirubin test.

Alanine Transaminase↗

PubMed1989

Effect of D-galactosamine on blood clearance of 99mTc-phytate in dogs.

The effect of D-galactosamine (GalN) on the blood clearance of 99mTc-phytate (99mTc-P) in dogs was examined, and the blood clearance test of 99mTc-P was compared with the cases of the serum transaminase and bilirubin test. Serum transaminase and bilirubin levels in dogs increased dose-dependently after GalN administration, and the degree of increase in these parameters was much higher than the cases in rats. The disappearance rate of 99mTc-P from blood in dogs decreased with the increase in dose of GalN and with the passage of time after the GalN administration. Changes of the blood clearance of 99mTc-P after GalN treatment in dogs may be influenced by the disorder in the hepatocytes. The blood clearance test of 99mTc-P in dogs showed a sensitive reaction for the acute hepatic dysfunction induced by GalN equally to the serum transaminase and bilirubin test.

Alanine Transaminase↗

PubMed1989

Effect of alpha-naphthylisothiocyanate on blood clearance of 99mTc-phytate in rats.

The effect of alpha-naphthylisothiocyanate (ANIT) on blood clearance of 99mTc-phytate (99mTc-P) in rats was examined, and blood clearance test of 99mTc-P was compared with the cases of serum transaminase test, serum bilirubin test or histological test of the liver. The disappearance rate of 99mTc-P from blood decreased with the increase in dose of ANIT and with the passage of time after the ANIT administration. Changes of the blood clearance of 99mTc-P after ANIT treatment in rats may be influenced by the disorder in the hepatocytes rather than in the bile ductule cells. The blood clearance test of 99mTc-P in rats showed a sensitive reaction for the acute hepatic dysfunction induced by ANIT equally to the serum transaminase test, the serum bilirubin test or the histological test of the liver.

1-Naphthylisothiocyanate↗