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Biomedical subjects

S Iida

Publications and source records attributed to S Iida.

At least 289 records · Page 16Linked to original sources
PubMed1989

Properties of glucocorticoid receptors in Epstein-Barr virus-transformed lymphocytes from patients with familial cortisol resistance.

In a previous report of two patients with familial glucocorticoid resistance due to reduced numbers of glucocorticoid receptors (GR), we have shown decreased numbers of GR in peripheral mononuclear cells and cultured fibroblasts but normal affinity of GR in both patients. In this study, peripheral lymphocytes from these patients, one patient's son and daughter, and normal subjects were transformed with Epstein-Barr virus. Reduced numbers and normal affinity of GR were found in the Epstein-Barr virus-transformed lymphocytes from both patients while the son and daughter had normal numbers and affinity of GR. The thermal stability of GR and thermal activation of cytosolic receptors in both patients were found to be normal. Although the percentages of nuclear bound GR were similar in both patients and normal controls, the absolute amounts of nuclear bound GR of the patients were about one-half that of normal controls. These abnormal properties of GR (reduced numbers of GR) were preserved in the transformed cells from the patients.

Cell Transformation, Viral↗
PubMed1989

Bent DNA is needed for recombinational enhancer activity in the site-specific recombination system Cin of bacteriophage P1. The role of FIS protein.

A series of recombinational enhancer mutants was constructed by manipulating the ClaI site between the two FIS binding sites of the Hin enhancer. These mutants include insertions from two to 12 base-pairs and two deletions of one or two base-pairs. Recombinational enhancer activity was found only with four mutants carrying either a four base-pair substitution, ten base-pair insertions or a one base-pair deletion, respectively; two other ten base-pair insertion mutants, however, were inactive, although FIS protein binding was unaffected. So, besides binding of FIS protein to its specific sites within the enhancer sequence and the correct helical positioning of these sites on the DNA, another criterion for enhancer activity must be fulfilled. DNA bending assays identify this requirement as a change of the enhancer DNA conformation, which FIS protein is able to induce and to stabilize. This conformational change of the DNA can be blocked by mutations in the central segment between the two FIS binding sites of the Hin enhancer. This sequence has special functions for the recombinational enhancer activity.

Bacteriophages↗
PubMed1989

The histological effects of cryocoagulation on the myocardium and coronary arteries.

The effects of epicardial and endocardial cryolesions were histologically studied in 29 dogs. To produce epicardial lesions, hypothermic exposure was applied at -60 degrees C for 3 minutes, over or adjacent to the left anterior descending coronary artery. To produce endocardial lesions, exposure was applied at -60 degrees C for 2 minutes, using the inflow occlusion technique over the ventricular septum. The dogs were killed 30 minutes to 6 months later. The cryolesions were sharply demarcated from the surrounding tissues and showed similar healing processes. The lesions showed no tendency to form aneurysms or rupture, although moderate intimal thickening of the coronary artery subjacent to the probe was observed. Our results indicate that cryocoagulation may greatly contribute to the surgical treatment of cardiac arrhythmias.

Animals↗
PubMed1989

Structural change of the troponin C molecule upon Ca2+ binding measured in solution by the X-ray scattering technique.

The small-angle X-ray scattering technique was used to characterize the overall structural change as well as the state of aggregation of troponin C upon binding various amount of Ca2+ ions: in the Ca2+-free state and at pCa 6.5 and 4.0. Under these conditions, the forward scattering intensities of troponin C are not much different from each other: i.e., they coincide within 4%. From these intensities, the Ca2+-facilitated dimerization of troponin C was not verified, and no appreciable aggregation of troponin C molecules was detected below pCa 4.0. Thus, the small-angle X-ray scattering profiles from troponin C solutions were analyzed assuming a monomeric molecule. The radii of gyration of troponin C were 27.8 +/- 0.3 A, 23.8 +/- 0.2 A, and 22.6 +/- 0.1 A for the Ca2+-free state and at pCa 6.5 and 4.0, respectively. The maximum dimension of the molecule decreases from 111 to 98 A with increasing Ca2+ concentration. These results indicate that the troponin C molecule shrinks remarkably as Ca2+ ions bind to the high affinity sites of the molecule. Ca2+ binding to the low affinity sites, on the other hand, leads to a less pronounced change. Following the interpretation of scattering from the dumbbell-shaped structure (Fujisawa, T., Ueki, T., Inoko, Y., & Kataoka, M. [1987] J. Appl. Cryst. 20, 349-355), the two domains of the molecule move closer to each other. The distance between the centers of the two domains decreases from 46 to 35 A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The influence of exogenous free cholesterol on steroid synthesis in cultured adrenal cells.

Previous studies showed that Y-1 cells in which the concentration of cholesterol in plasma membranes (expressed relative to phospholipid as a molar ratio, C/P) was raised by incubation with cholesterol produced more 20 alpha-dihydroprogesterone than cells with normal or low plasma membrane C/P values. This difference was not associated with any difference in the production of cAMP. The cells respond to (Bu)2cAMP in the order high greater than normal greater than low C/P. High C/P is associated with higher levels of cholesterol in the cytosol and higher concentrations of this steroid in the inner mitochondrial membrane. The rate of transport of cholesterol to the inner membrane differed in the three groups of cells: high greater than normal greater than low C/P. Production of pregnenolone by mitoplasts was no different in the three groups, and the same applies to the production of pregnenolone by mitochondria from cells incubated with and those incubated without (Bu)2cAMP. 25-Hydroxycholesterol increased the production of 20 alpha-dihydroprogesterone by cells showing normal or low C/P values, but not those with high values. It is concluded that the transport of cholesterol to the inner mitochondrial membrane is regulated by at least two processes, namely the supply of substrate (cholesterol), which can saturate this transport mechanism, and some mechanism(s) that is stimulated by cAMP and is capable of stimulating transport above maximal levels produced by high concentrations of cholesterol alone. The second mechanism requires the synthesis of a new protein(s).

20-alpha-Dihydroprogesterone↗
PubMed1989

[General pharmacological studies on 5,8,11,14,17-eicosapentaenoic acid ethyl ester (EPA-E)].

EPA-E, even at 3,000 mg/kg, p.o., did not affect the general behaviors, spontaneous locomotor activities, pentobarbital hypnosis and body temperature; and it did not elicit anticonvulsant, analgesic and muscle relaxant actions. It had no influence on spontaneous EEG activities, even at 3,000 mg/kg, i.d. EPA-E at concentrations up to 10(-4) M, did not affect the tonus or agonist-induced contraction of the isolated ileum, trachea, fundus and vas deferens. EPA-E had no influence on the spontaneous movement of isolated ileum or uterus. EPA-E did not affect the nictitating membrane contraction and intestinal propulsive motility, and it did not damage gastric mucosa nor elicit antiulcer action. EPA-E at 1,000 mg/kg were without effect on gastric secretory volume (SV), total acidity (TA) and pepsin activities (PA). However, EPA-E at 3,000 mg/kg significantly decreased SV and TA without significantly decreasing PA. EPA-E caused no changes in the respiration, blood pressure, heart rate and ECG at the doses up to 3,000 mg/kg; and it did not affect the heart rate and contractile force on the isolated atria at concentrations up to 10(-4) M. The intracutaneous injection of 2.0% EPA-E produced neither anesthetic nor irritative action. EPA-E did not elicit hemolytic action at 10(-4) M. EPA-E, even at 3,000 mg/kg, did not affect the neuro-muscular transmission, urine volume, urinary excretion of electrolytes and carrageenin edema. These results suggested that EPA-E has no noticeable effects on the central nervous, autonomic nervous, respiratory and cardiovascular systems and so on.

Animals↗
PubMed1989

Treatment of posttransfusion non-A, non-B acute and chronic hepatitis with human fibroblast beta-interferon: a preliminary report.

We treated five patients with posttransfusion non-A, non-B chronic active hepatitis and six patients with posttransfusion non-A, non-B acute hepatitis with 3 million units of human fibroblast beta-interferon three times weekly for 4 wk. Initiation of interferon therapy was followed by a prompt and marked decrease in serum aminotransferase activity in five patients with chronic active hepatitis and five patients with acute hepatitis; the exception was one patient with acute hepatitis in whom serum aminotransferase levels fluctuated during treatment. Biopsy specimens obtained immediately after therapy showed improvement in hepatic histology in two of four patients with chronic active hepatitis and three of four patients with acute hepatitis. Cessation of interferon therapy was followed by a prompt increase in serum aminotransferase levels in five patients with chronic active hepatitis and in one patient with acute hepatitis, although re-elevated serum aminotransferase levels returned gradually to the normal range in the patient with acute hepatitis, but did not do so in five patients with chronic active hepatitis. In another patient with acute hepatitis whose serum aminotransferase levels fluctuated during interferon therapy, serum aminotransferase levels reached normal range after discontinuation of therapy. At 6 months and 12 months after discontinuation of interferon therapy, all five patients with chronic active hepatitis showed elevated serum aminotransferase levels, and all six patients with acute hepatitis showed normal serum aminotransferase levels. These results suggest that short-term and low doses of beta-interferon therapy has an only temporal effect on controlling the disease activity in patients with posttransfusion non-A, non-B chronic active hepatitis, and it might become an effective therapy for posttransfusion non-A, non-B acute hepatitis.

Acute Disease↗
PubMed1989

[Percutaneous transhepatic portography in patients with hepatocellular carcinoma: percutaneous transhepatic portal venous embolization].

Percutaneous transhepatic portography was performed in 28 patients with HCC and PTPE was attempted in 9 of them. Displacement of the portal vein was found in 37% of 52 HCCs. Other portographic findings were: encasement (19%), avascular area (19%), occlusion (10%), narrowing (4%), neovascularization (4%), tumor staining (2%). Frequency of the tumor-related portography findings was found to be increased in relation to tumor size. TAE followed by PTPE with stainless steel coil (6 cases) or microcapsule form of MMC (3 cases) was performed on 9 cases. PTPE appears to be a promising adjuvant to conventional TAE.

Aged↗
PubMed1989

Splanchnic hemodynamics in idiopathic portal hypertension: comparison with chronic persistent hepatitis.

A comparative study of splanchnic hemodynamics was made in 12 patients with idiopathic portal hypertension and in eight patients with chronic persistent hepatitis, but without portal hypertension, who served as the control. Venous pressures were measured by portal and hepatic vein catheterizations, blood flow by the pulsed Doppler flowmeter, and organ volume by computed tomography. Splenic artery blood flow was 788 +/- 242 ml/min in idiopathic portal hypertension and about four times that in chronic persistent hepatitis (215 +/- 42 ml/min), whereas there was no difference in superior mesenteric artery blood flow between the former and the latter (408 +/- 142 vs. 389 +/- 32 ml/min). Spleen volume in idiopathic portal hypertension was six times that in chronic persistent hepatitis, and splenic artery blood flow showed a significant linear correlation with spleen volume in idiopathic portal hypertension (r = 0.71, p less than 0.02). The sum of splenic artery blood flow and superior mesenteric artery blood flow in idiopathic portal hypertension was 1195 +/- 294 ml/min, twice that in chronic persistent hepatitis (603 +/- 109 ml/min). Portal vascular resistance and intrahepatic portal vascular resistance were three times and four times those in chronic persistent hepatitis, respectively. These results indicate that both increased intrahepatic portal vascular resistance and increased splenic artery blood flow may play roles in the development of portal hypertension in idiopathic portal hypertension.

Adult↗
PubMed1989

Differences in portal hemodynamics in cirrhosis and idiopathic portal hypertension.

A comparative study of portal hemodynamics was made in 79 cirrhotics (24 cirrhotics with a large spleen greater than or equal to 500 cm3 in volume, 55 cirrhotics with a spleen less than 500 cm3 in volume), 22 patients with idiopathic portal hypertension, and 63 healthy adults who served as the control for portal and splenic venous flows. Portal and splenic venous flows were significantly increased in the group order of the cirrhosis without splenomegaly group, the cirrhosis with splenomegaly group, and idiopathic portal hypertension group. Intrahepatic shunt index was significantly greater in the cirrhosis with splenomegaly group than in the cirrhosis without splenomegaly group, and it was negligible in the idiopathic portal hypertension group. Portal vein pressure was significantly elevated in the cirrhosis with splenomegaly group than in the cirrhosis without splenomegaly and idiopathic portal hypertension groups. Postsinusoidal resistances were significantly greater in the two groups of cirrhosis than in the idiopathic portal hypertension group, whereas presinusoidal resistance was significantly greater in the idiopathic portal hypertension group than in the two groups with cirrhosis. It is concluded that these differences are inconsistent with the view that cirrhosis with splenomegaly comes from idiopathic portal hypertension.

Female↗
PubMed1988

Random mutagenesis using degenerate oligodeoxyribonucleotides.

An efficient method for random mutagenesis was applied to a 75-bp target sequence. The mutational changes in the target region are introduced by the technique of oligodeoxyribonucleotide(oligo)-directed, site-specific mutagenesis using mixtures of degenerate oligos. These are designed in such a way that they carry with a high probability randomly distributed substitutions, which are introduced into the oligos by utilizing appropriate concentrations of all four nucleotide precursors during each chain elongation step. These mixtures of degenerate oligos were hybridized to the appropriate M13-hybrid ss-template and then extended in vitro using PolIk. In order to avoid any bias artificially created by the Escherichia coli mismatch repair system, homoduplex molecules were synthesized in vitro according to the method of Taylor et al. [Nucleic Acids Res. 13 (1985) 8765-8785]. After transformation of the appropriate E. coli host, M13 plaques were randomly analysed by DNA sequencing. Using appropriate preparations of template DNA and oligos we attained mutagenesis efficiencies in the range of 20-50%. The analysis of 85 different mutants revealed that the distribution of the mutations is random and that all expected substitutions occur with about the same probability.

Base Sequence↗