Search PubMed⌕ Search

Biomedical subjects

H Maruta

Publications and source records attributed to H Maruta.

At least 91 records · Page 5Linked to original sources
PubMed1989

A new closed-system using partially frozen injectate for thermodilution cardiac output determinations.

The FI (partially frozen injectate) system, a new closed-system devised by the authors for thermodilution cardiac output determinations, has two major features: 1) it needs no ice-filled receptacle to keep injectate cold because it uses partially frozen injectate, and 2) it can go without monitoring the injectate temperatures during the whole process of cardiac output determinations. The author evaluated the accuracy and reproducibility of cardiac output determinations with the FI system in 10 critically ill patients, as compared with another closed-system (which is commercially available) and the standard open method. The injectate temperatures in the FI system were also measured in vitro. The mean injectate temperature in the FI system was 0.71 +/- 0.26 degrees C and 80% of the injectate temperatures were lower than 1.0 degrees C. Even when no monitoring of injectate temperatures was made, the predicated error in the calculated cardiac output resulted as low as 2% with the FI system. The mean cardiac output values were not statistically different between the FI system and the other two systems.

Journal Article↗
PubMed1989

Direct formation of angiotensin II without renin or converting enzyme in the ischemic dog heart.

An in vivo study was done to determine whether angiotensin II is directly formed by kallikrein or kallikrein-like proteases. Dogs were bilaterally nephrectomized 24 hours before ligation of the coronary artery. This acute coronary artery occlusion led to a regionally increased acidic state in the ischemic tissue and resulted in an elevation of immunoreactive angiotensin II (IR-Angiotensin II) levels in the coronary sinus blood, but not in systemic aortic blood. Elevation of the IR-Angiotensin II level was specifically inhibited by aprotinin, a kallikrein inhibitor. It was not affected by either captopril, a potent angiotensin converting enzyme inhibitor, or by pepstatin, a renin inhibitor. The concentrations of immunoreactive angiotensin I (IR-Angiotensin I), plasma renin activity and angiotensin converting enzyme activity remained unaltered in the presence of coronary artery occlusion. These results suggest that IR-Angiotensin II in the ischemic heart may be generated directly by kallikrein or kallikrein-like proteases, independently of the systemic renin angiotensin system.

Angiotensin II↗
PubMed1989

[Study on cases of precocious puberty].

Two boys and one girl with idiopathic precocious puberty were treated with medroxyprogesterone acetate (MPA) for 2 years and 2 months to 9 years and 5 months, and its efficiency was evaluated. Treatment with MPA suppressed the gonadotropin levels, the signs and symptoms of patients with precocious puberty, and also had a suppressive effect on bone-age advance, so these patients showed almost normal growth in height. There has been controversy about the age when treatment for idiopathic precocious puberty should be finished. Our data suggested that the treatment should be stopped at 11-13 years when patients reach the age of puberty.

Adolescent↗
PubMed1989

[A clinical study of congenital adrenal hyperplasia].

We have compared three treatments of congenital adrenal hyperplasia (CAH) for their effect on physical development. Thirteen girls and two boys with CAH due to 21-hydroxylase deficiency were treated with three different treatments, hydrocortisone (HC), dexamethasone (DXM) and cyproterone acetate (CA). The results showed that height growth was better with HC and CA than DXM, and bone excessive maturation was more suppressed with DXM and CA than HC. A dose-dependent relationship was revealed between body weight and dose of HC. Iatrogenic obesity was found in 42.9% and 38.1% of the patients treated with DXM and HC, but none of the patients treated with CA did became obese. Physical growth was better with CA treatment than HC or DXM treatment, but CA may have a suppressive effect on the pituitary-adrenal axis observed carefully, especially on prepubertal and pubertal cases.

Adrenal Hyperplasia, Congenital↗
PubMed1988

Formation of angiotensin II by tonin-inhibitor complex.

Enzymatic activity of tonin-alpha 1-macroglobulin complex was studied in vitro and in vivo, using an immunoimmobilization technique. Tonin-alpha 1-macroglobulin complex, which was immunologically immobilized by anti-alpha 1-macroglobulin antibody covalently coupled to agarose gels, could quantitatively hydrolyze angiotensin I and synthetic tridecapeptide renin substrate to form angiotensin II. However, the solid-phase antibody-bound tonin-alpha 1-macroglobulin complex could not hydrolyze the plasma protein renin substrate. Phenylmethylsulfonyl fluoride, a serine protease inhibitor, inhibited both free tonin and the solid-phase antibody-bound tonin-alpha 1-macroglobulin complex. The hydrolytic activity of the solid-phase antibody-bound tonin-alpha 1-macroglobulin complex against angiotensin I was not inhibited by soybean trypsin inhibitor (molecular weight, 23,000), a potent inhibitor of free tonin. Taken together, these results suggest that tonin bound to alpha 1-macroglobulin keeps the active site intact and that inhibition of the enzyme activity is due to a steric hindrance. When 500 microliter of tonin was administered intravenously to rats, the immunoimmobilization method was used to show that the tonin-alpha 1-macroglobulin complex in the plasma formed angiotensin II. Thus, the tonin-alpha 1-macroglobulin complex in the plasma may be linked to some forms of hypertension through angiotensin II formation.

Angiotensin I↗
PubMed1988

[Studies on serum and urinary alpha 1-microglobulin levels as parameter of the renal function--renal function observed after CDDP administration].

To evaluate the clinical usefulness of alpha 1-microglobulin (alpha 1-MG) as parameter of renal function, we determined the levels of alpha 1-MG in the serum and urine of patients who had no malignant tumors, and compared them with the levels of beta 2-microglobulin (beta 2-MG), serum creatinine, urinary N-acetyl-beta-glucosaminidase (NAG) and 24-hour creatinine clearance (24 Ccr). There were significant positive correlations between alpha 1-MG in the serum and urine, and those of beta 2-MG levels. Serum alpha 1-MG and 24 Ccr were inversely correlated. Combined measurements of alpha 1-MG in the serum and urine seemed to be useful to estimate glomerular and tubular renal functions. The renal function in 8 patients with advanced urogenital cancers treated with cis-diammine-dichloroplatinum (CDDP) was examined by measuring 24 Ccr, alpha 1-MG, and beta 2-MG in serum and urine and urinary NAG. Determination of urinary alpha 1-MG was useful for early detection of tubular damage after CDDP administration.

Acetylglucosaminidase↗
PubMed1988

[Clinical efficacy of mecobalamin in the treatment of oligozoospermia--results of double-blind comparative clinical study].

The clinical efficacy of mecobalamin in the treatment of male infertility was investigated by means of a multicenter collaborative study with 25 participating institutions. The study was carried out as a double-blind, comparative trial using three administration groups: 6,000 micrograms of mecobalamin per day, 1,500 micrograms of mecobalamin per day and a placebo group for 12 wk. The following results were obtained. 1. The total number of evaluated subjects was 375, consisting of 125 in the 6,000 micrograms/day mecobalamin group, 124 in the 1,500 micrograms/day mecobalamin group and 126 in the placebo group. There were no significant differences among the three administration groups in terms of the patient's background factors. 2. When all of the patients were analyzed, there were no statistically significant differences among the three administration groups in terms of the efficacy in relation to the sperm count or the motility rate. 3. However, it was decided to perform a more detailed analysis of the therapeutic efficacy in patients whose pretreatment sperm counts were 20 x 10(6)/ml or less. The reasons for this decision were two-fold: 1) There was a large degree of fluctuation in patients whose pretreatment sperm counts showed a mean value of more than 20 x 10(6)/ml for two or more determinations, and it was surmised that this fluctuation might have masked any therapeutic effect in those cases. 2) The WHO definition of oligozoospermia was recently decided as a sperm count of 20 x 10(6)/ml or less.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Activation of human prorenin by neutrophil elastase.

Although about 90% of human renin circulates as inactive prorenin, the mechanism of prorenin activation in vivo is not known. We found that human polymorphonuclear leukocytes (PMN) activate prorenin at a neutral pH. Prorenin was partially purified from human amniotic fluid, and its activation was measured by the release of angiotensin I from sheep angiotensinogen. In control experiments, thermolysin was the standard activator. PMN cells were separated from blood and, after N2 cavitation or degranulation by cytochalasin, were fractionated by differential centrifugation. Elastase and cathepsin G activities were determined with synthetic fluorescent substrates. The activators of prorenin concentrated in the azurophil granules were released by Triton; most of the activation was due to elastase. Elastase, purified from human PMN, activated prorenin completely. The activation by the granular fraction was inhibited 77% by a specific elastase inhibitor in the presence of a detergent, but only 22% by a cathepsin G inhibitor. After inhibition of elastase, the residual activity was inhibited by diisopropylfluorophosphate; thus, it was due to a serine protease(s) such as cathepsin G. We suggest that human renin fully activated by elastase may still contain an N-terminal pentapeptide fragment of the propeptide.

Amniotic Fluid↗
PubMed1986

The acetylation of alpha-tubulin and its relationship to the assembly and disassembly of microtubules.

A tight association between Chlamydomonas alpha-tubulin acetyltransferase (TAT) and flagellar axonemes, and the cytoplasmic localization of both tubulin deacetylase (TDA) and an inhibitor of tubulin acetylation have been demonstrated by the use of calf brain tubulin as substrate for these enzymes. A major axonemal TAT of 130 kD has been solubilized by high salt treatment, purified, and characterized. Using the Chlamydomonas TAT with brain tubulin as substrate, we have studied the effects of acetylation on the assembly and disassembly of microtubules in vitro. We also determined the relative rates of acetylation of tubulin dimers and polymers. The acetylation does not significantly affect the temperature-dependent polymerization or depolymerization of tubulin in vitro. Furthermore, polymerization of tubulin is not a prerequisite for the acetylation, although the polymer is a better substrate for TAT than the dimer. The acetylation is sensitive to calcium ions which completely inhibit the acetylation of both dimers and polymers of tubulin. Acetylation of the dimer is not inhibited by colchicine; the effect of colchicine on acetylation of the polymer can be explained by its depolymerizing effect on the polymer.

Acetylation↗
PubMed1986

Partial trisomy for the distal part of the long arm of chromosome 15--a new syndrome?

A malformed male neonate with partial trisomy 15q dist (q22----qter), because of malsegregation of a balanced translocation (7; 15) (p22; q22) in his mother, is described. Comparison of this patient with thirteen previously published cases of this trisomy reveals a pattern of common features including: peculiar craniofacial dysmorphism--facial asymmetry, antimongoloid slant, narrow or short palpebral fissures, prominent nose, long upper lip, micro or retrognathia, high arched palate, low set ears, malformed ears, protuberant occiput--, abnormal fingers and toes, short neck, mental and growth retardation, cardiopathy, respiratory distress etc.. The main clinical findings seem to be similar enough to justify the establishment of a new entity of partial trisomy 15q dist syndrome.

Abnormalities, Multiple↗
PubMed1985

Monoclonal antibodies localize the exchangeable GTP-binding site in beta- and not alpha-tubulins.

A combination of several methods was used to localize the exchangeable GTP-binding site in the alpha/beta-tubulin heterodimer: direct photoaffinity labeling with [alpha-32P]GTP, specific labeling of alpha- and beta-tubulin by tyrosylation and phosphorylation, respectively, and immunoprecipitation with specific monoclonal antibodies. Direct evidence was obtained that GTP binds exclusively to beta- and not alpha-tubulins.

Animals↗
PubMed1985

Alpha-tubulin acetylase activity in isolated Chlamydomonas flagella.

We have previously shown that the alpha-tubulin of Chlamydomonas flagella is synthesized as a precursor which is modified by acetylation in the flagellum during flagellar assembly. In this report, we show the presence of an alpha-tubulin acetylase activity in isolated Chlamydomonas flagella that is highly specific for alpha-tubulin of both mammalian brain and Chlamydomonas.

Acetyltransferases↗
PubMed1984

Localization of two phosphorylation sites adjacent to a region important for polymerization on the tail of Dictyostelium myosin.

Phosphorylation of the myosin heavy chains of Dictyostelium discoideum is known to be inhibited following chemotactic stimulation of the cells. Effects of dephosphorylation on the assembly of myosin and on its actin-activated ATPase activity raised the question of where the phosphorylated sites are located with respect to sites responsible for polymerization and actin binding. Using seven monoclonal antibodies the binding sites of which were mapped in the electron microscope, two phosphorylation sites, i.e., threonine residues that were phosphorylated by a kinase from D. discoideum, were localized by immunoblotting of chymotryptic fragments. Two of the antibodies bound to the terminal one fifth of the tail and recognized a phosphorylated chymotryptic fragment of 38 kd. The non-phosphorylated form and single and double phosphorylated forms of this fragment were separated by two-dimensional electrophoresis. Antibody labeling of lower mol. wt. polypeptides indicated that both phosphorylation sites were located at least 32 kd from the end of the tail. A non-phosphorylated fragment, that was insoluble at low ionic strength due to polymerization, proved to be an internal cleavage product of the tail. A segment of this fragment necessary for polymerization was mapped adjacent to the phosphorylation sites.

Journal Article↗
PubMed1984

Ca2+-dependent actin-binding phosphoprotein in Physarum polycephalum. Subunit b is a DNase I-binding and F-actin capping protein.

Physarum contains at least two distinct DNase I-binding proteins, i.e. actin and Cap 42 (a + b). The latter, a tight (1:1) complex of Cap 42 (a) and Cap 42 (b) (Maruta, H., Isenberg. G., Schreckenbach, T., Hallmann, R., Risse, G., Schibayama, T., and Hesse, J. (1983) J. Biol. Chem. 258, 10144-10150), is a Ca2+-dependent F-actin capping protein. DNase I binds to Cap 42 (b) but not to Cap 42 (a). Consequently, DNase I-agarose was used for an affinity-purification of Cap 42 (a + b), after its separation from actin by DEAE-cellulose chromatography. Cap 42 (a + b) was dissociated into its subunits when released from DNase I-agarose by 8.8 M formamide. The two subunits were subsequently separated from each other on hydroxylapatite. Both Cap 42 (a) and Cap 42 (b) were Ca2+-dependent F-actin capping proteins that cap the fast growing end of actin filaments and block actin polymerization at this end. Like Cap 42 (a + b), Cap 42 (b) required Ca2+ for its capping activity only when phosphorylated. The phosphorylation of Cap 42 (b) was completely blocked by DNase I or a tertiary complex of Cap 42 (a), actin, and Ca2+. Cap 42 (b) is not identical with native (= polymerizable) actin because (i) Cap 42 (b) was unable to form filaments, (ii) the Cap 42 (b) kinase did not phosphorylate native actin, and (iii) fragmin formed a tight (1:1) complex with native actin but not with Cap 42 (b). Although it is unlikely that Cap 42 (b) is simply a denatured form of actin that has lost its polymerizability during the preparation, it still remains to be clarified whether Cap 42 (b) is a nonpolmerizable actin variant derived from a distinct actin gene or a post-translationally modified form of polymerizable actin.

Actins↗