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Biomedical subjects

R Ikeda

Publications and source records attributed to R Ikeda.

At least 19 recordsLinked to original sources
PubMed1992

Heterogeneity of phenol oxidases in Cryptococcus neoformans.

Phenol oxidase enzymes, linked to virulence in Cryptococcus neoformans, were prepared from broken cells. More enzyme activity was found in the ultracentrifugation supernatant; less was found in the membrane fraction. Phenol oxidases were located in acrylamide gel electropherograms by activity staining with L-dihydroxyphenylalanine (DOPA). Mobility differences between soluble and solubilized membrane-bound phenol oxidases were not found. Comparison of enzymes produced at 25 and 37 degrees C revealed that the enzyme had lower activity and lower mobility at 37 degrees C. The mobility of 25 degrees C phenol oxidases from strains of C. neoformans var. gattii was lower than that of those from C. neoformans var. neoformans. Half of the phenol oxidase produced at 25 degrees C was bound by concanavalin A, while that produced at 37 degrees C was not bound. However, glucose starvation of cultures at 25 degrees C overnight resulted in increased amounts of enzyme which did not bind to concanavalin A. A given strain of C. neoformans produces different species of phenol oxidase under different culture conditions.

Cryptococcus neoformans↗
PubMed1992

[Rat brain concentrations of monoamines and their metabolites after chronic administration of diazepam and tandospirone].

Tandospirone has been reported as a serotonergic antianxiety drug with a different pharmacological mechanism from benzodiazepines. In the present study, the brain concentrations of monoamines and their metabolites were measured, comparing control rats and two groups of rats which were given tandospirone (10 mg/kg, ip) and diazepam (5 mg/kg, ip) each for 14 days. After sacrifice, brains of all animals were cut and divided into three portions, i.e. the cortex (COR), cerebellum (CER) and subcortical structures and brain stem (SS & BS). The concentrations of COR and SS & BS were measured using a Neurochemicalanalyzer (NCA, ESA, Inc., USA) with a reverse-phase column (Neurocolumn, Niko Bioscience Inc.). In the COR, 3-O-MDOPA (3-O-methyldopa) increased in the tandospirone group. In the SS & BS, 3-O-MDOPA increased in the diazepam and tandospirone groups. 5HIAA (5-hydroxyindoleacetic acid), DOPAC (3,4-dihydroxyphenylacetic acid) and HVA (homovanillic acid) decreased in the tandospirone group.

Animals↗
PubMed1992

[Evaluation of diet of calcium stone patients].

To clarify the relationship between renal stone formation and the diet, the consumption of various nutrients of calcium stone formers was investigated. The study included 24 male and 12 female stone formers, between 20 and 78 years old (mean 42 years). The daily consumption of nutrients was compared to the daily nutritive requirement for the Japanese. The amounts of total and animal protein ingested by all the patients were significantly larger than the daily nutritive requirements. The animal protein ratio was also significantly higher. Concerning the total protein, animal protein and animal protein ratio, male and female patients showed similar results. Salt consumption was significantly larger for all the patients and the male patients than the daily nutritive requirement for the Japanese. Female stone formers also showed this tendency. Consumption of calcium and carbohydrate by all the patients and the male patients was significantly smaller than the daily nutritive requirement. This tendency was observed for the female patients.

Adult↗
PubMed1991

Comparison of serological and chemical characteristics of capsular polysaccharides of Cryptococcus neoformans var. neoformans serotype A and Cryptococcus albidus var. albidus.

The antigenic formula and chemical structure of capsular polysaccharide (CPS) of Cryptococcus albidus var. albidus (C. albidus) were studied in relation to those of C. neoformans var. neoformans serotype A (C. neoformans A). The results of slide agglutination tests with factor sera and reciprocal adsorption experiments showed that antigenic formula of C. albidus was the same as that of C. neoformans A. The soluble CPSs from the two species were obtained from culture supernatants by precipitation with ethanol followed by purification by chromatography on DEAE-cellulose column. The structural analyses of such CPSs from the two species showed that the antigenic CPS fractions consisted of a backbone of alpha(1-3)-linked D-mannopyranosyl residues with a single branch of beta(1-2)-xylose or glucuronic acid, and mostly with O-acetyl groups, in which side chains and O-acetyl groups were responsible for antigenic specificity. It was found that there was a minor difference between the CPS of C. neoformans A and that of C. albidus; in the former, unsubstituted mannose residues existed in a low frequency, but in the latter none. Moreover, the 1H-nuclear magnetic resonance spectra of partially hydrolyzed acidic fragments of the two CPSs indicated that two xylose side chains were present between glucuronic acid side chains. Taken together, it was suggested that these two species of C. neoformans A and C. albidus are closely related to each other in their CPSs.

Animals↗
PubMed1991

Evaluation of a new method for identification of Cryptococcus neoformans which uses serologic tests aided by selected biological tests.

A new method for identifying Cryptococcus neoformans isolates and their serotypes by the slide agglutination test using five kinds of factor sera, with the aid of nitrate reduction, phenol oxidase, and growth at 37 degrees C tests was evaluated by using 36 reference strains and 75 clinical isolates of C. neoformans. The results showed that the reference strains were identified exactly as they were labeled, and clinical isolates were identified as C. neoformans serotypes A, D, and AD. C. neoformans could be distinguished from other Cryptococcus species that cross-reacted with factor sera by their ability to grow at 37 degrees C. These results indicate that the slide agglutination test combined the use of factor sera for isolates which grow at 37 degrees C is a useful method for identification of C. neoformans and their serotypes and that the nitrate reduction test (negative in 100% of the isolates) and the phenol oxidase test (positive in approximately 95% of the isolates) can be used to confirm that the species is C. neoformans.

Agglutination Tests↗
PubMed1991

[Innervation of the sacroiliac joint. Macroscopical and histological studies].

Macroscopical and histological studies were carried out to clarify nerve innervation of the sacroiliac joint which is believed to have a role in the development of low back pain. Eighteen Japanese adult cadavers were used for gross anatomical examination and six for histological examination of the nerve supply to the joint. The results were as follows: 1) It is suggested by the gross examination that the upper ventral portion of the joint is mainly innervated by the ventral ramus of the 5th lumber nerve. 2) The lower ventral portion of the joint was mainly supplied by the ramus of the 2nd sacral nerve or branches from the sacral plexus. 3) Lateral branches of the dorsal ramus of the 5th lumber nerve were considered to be the main nerves which innervated the upper dorsal portion of the joint. 4) The lower dorsal portion was innervated by nerves arising from a plexus composed of lateral branches of the dorsal rami of the sacral nerves. 5) The nerves which innervate the joint range in diameter from 0.292 mm to 0.997 mm, and no difference was found among those in the four subdivisions of the joint. 6) Histological examination revealed that nerve fibers and the terminals were present in the joint capsule and adjoining ligaments. The nerve fibers varied from 0.2 micron to 2.5 microns in diameter and ended with five morphologically different terminals.

Adult↗
PubMed1991

A novel fibrinolytic enzyme extracted from the earthworm, Lumbricus rubellus.

A strong fibrinolytic enzyme was readily obtained in saline extracts of the earthworm, Lumbricus rubellus. It hydrolyzed not only plasminogen-rich fibrin plates, but also plasminogen-free fibrin plates. The average fibrinolytic activity was about 100 CU (plasmin units) or 250 IU (urokinase units)/g wet weight. The molecular weight and isoelectric point were about 20,000 and 3.4, respectively. The enzyme was heat-stable and displayed a very broad optimal pH range. DFP and SBTI strongly inhibited the enzyme, but the anti-plasmin agent, t-AMCHA, exerted little effect under the same conditions. Purification of the enzyme was performed and three partially purified fractions were obtained. These three fractions were further subdivided. The first fraction (F-I) was divided into three fractions (F-I-0, F-I-1, and F-I-2), which exhibited similar biochemical characteristics. The second fraction (F-II) could not be subdivided. The third fraction (F-III) was divided into two fractions (F-III-1 and F-III-2). Based on results for their enzymatic activities against various substrates, the fraction I enzymes are thought to represent a chymotrypsin-like enzyme and the fraction III enzymes to represent a trypsin-like enzyme. The fraction II enzyme appears to be neither a trypsin- or chymotrypsin-like enzyme nor an elastase. The amino acid compositions of the six enzymes were estimated. Compared with other serine enzymes, these enzymes contained very abundant asparagine or aspartic acid, and there was very little proline or lysine. From the above data, these enzymes are regarded as novel fibrinolytic enzymes, and we name them collectively as Lumbrokinase from the generic name of the earthworm.

Amino Acids↗
PubMed1991

[Renal carcinoma in hemodialysis patients. Specially concerned with acquired cyst].

Acquired cystic disease of the kidney (ACDK) with carcinoma in the original kidney is one sensational complication of long-term hemodialysis patients. The rate of incidence is about forty times higher than that in the general population and especially high in the young male group. From Dec. 1978 to Nov. 1990, we identified 8 patients of ACDK by computerized tomography (CT) scan, sonographic examination and angiography. Most patients had no clinical symptoms. The mean term of hemodialysis of the patients was 8 yrs. And one patient was diagnosed as having ACDK and tumor 8 yrs after kidney transplantation and then the kidney was removed. Their mean age was about 32 y.o. and the tumor size 1-3 cm in diameter. All tumors were inside the renal capsule. (Robson-1) Pathohistologically, the tumor area consisted of mainly clear cell carcinoma and the epithelium of the cyst wall showed multi-layered or papillary hyperplasia. In the 1st and 7th cases, simple nephrectomy was performed by transperitoneal approach. In the other cases it was performed by flank incision. All cases have had no recurrence and no metastasis of renal carcinoma. The etiology of ACDK and carcinoma occurrence has not been clarified yet, but it is suggested that uremic metabolite and deficiency of immuno-surveillance may cause the pathological changes in kidney tissue.

Adenocarcinoma↗
PubMed1991

[Technique and problems of total parathyroidectomy with autotransplantation in secondary hyperparathyroidism].

Between 1982 and 1990, 20 patients with chronic renal failure underwent total para-thyroidectomies and autotransplantations as treatment for secondary hyperparathyroidism. Fourteen cases were cured of their symptoms and their serum PTH levels was restored to normal. Recurrent hyperparathyroidism developed in 6 cases. In 3 of the 6 cases, excision of parathyroid tissue from the forearm could easily be performed under local anesthesia. Of the other cases, 2 had five and one had six glands. Several localizing methods should be performed before operation, in order to overlook the parathyroid glands in different anatomic positions.

Adult↗
PubMed1990

Carboxypeptidase activity in human urine from healthy subjects and renal disease patients.

We have attempted to estimate the carboxypeptidase activity in unconcentrated human urine by means of a colorimetric method in which Bz-Gly-Lys is employed as a substrate. Upon addition of both 1.6 mmol/l CoCl2 and 0.18 g/l bovine serum albumin to the assay solution at pH 5.6, the carboxypeptidase activity in human urine can be evaluated. Using our method, the daily excretion of carboxypeptidase in both healthy subjects and patients with renal diseases has been examined. The level is increased in patients with nephrotic glomerulonephritis (24.9 +/- 14.9 (SD) U/day; n = 8) and patients with nephritic glomerulonephritis (11.4 +/- 7.55 (SD) U/day; n = 14) as compared to that in healthy subjects (5.10 +/- 1.88 (SD) U/day; n = 18). However, it is decreased in patients with chronic renal failure (2.70 +/- 2.13 (SD) U/day; n = 12).

Cadmium↗
PubMed1990

Reassessment of antigenic determinant of Saccharomyces cerevisiae serotype Ia.

We examined the immunochemical structure of the antigenic determinant of S. cerevisiae serotype Ia. The specific factor serum for S. cerevisiae serotype Ia was obtained either from factor 18 serum by adsorption with heat-killed cells of Candida glabrata, or from anti-S. cerevisiae Ia (M 6001) serum by adsorption with heat-killed cells of S. cerevisiae Ib (IFO 0751). We designated this adsorbed serum as factor 18a. Acetolysis of S. cerevisiae cell wall D-mannan gave five oligosaccharides. Signals of 1H-nuclear magnetic resonance spectra of mannooligosaccharides derived from S. cerevisiae mannan were assigned for their linkages by the aid of those of alpha-1,3'-linked mannooligosaccharides derived from glucuronoxylomannan of capsule of Cryptococcus neoformans serotype A-D. Agglutination-inhibition experiments revealed that the mannopentaose from S. cerevisiae mannan was the most effective inhibitor. Moreover, inhibitory activities of alpha-1,3'-linked mannotriose, mannotetraose, and mannopentaose which were derived from glucuronoxylomannan of C. neoformans were shown to be higher than those of mannotetraose with one terminal alpha-(1-3) linkage from homologous S. cerevisiae mannan. These results indicate that mannopentaose with terminal two alpha-(1-3) linkages is responsible for the specificity of S. cerevisiae Ia.

Agglutination Tests↗
PubMed1990

Low molecular weight alanine aminopeptidase of human serum: separation and some characteristics.

An alanine aminopeptidase, which has characteristics different from those of known alanine cleaving aminopeptidases, was partially purified from human serum by Sephadex G-200 gel chromatography and DEAE Sepharose column chromatography. The enzyme exhibited a molecular weight of 58,000 by gel chromatography. The pI of the enzyme was 5.0, and it was inactivated at 60 degrees C in 20 min. The enzyme readily hydrolyzed L-alanine beta-naphthylamide, but hardly hydrolyzed the other tested beta-naphthylamides. The Km value for L-alanine beta-naphthylamide was 0.29 mM, the pH optimum 7.5. The activity of the enzyme was enhanced by chloride ions and by sulfhydryl ethylenediaminetetraacetic compounds, and was inhibited by sulfhydryl blocking ethylenediaminetetraacetic agents, and bestatin. Furthermore, 1.10 phenanthroline and ethylenediaminetetraacetic acid were inhibitory, and the activity was restored by CoCl2 and ZnCl2. The enzyme is a chloride-enhanced thiol dependent metalloaminopeptidase.

Aminopeptidases↗
PubMed1990

Diversion programs for impaired physicians.

Nine states have legislated impaired physician programs administered by state medical boards (2), by independent agencies (4), or by medical societies through contracts with medical boards (3). All other state programs are administered by medical societies. California's diversion program has been in effect for more than 10 years. It was the first program for alcohol- and drug-addicted physicians in the country administered by the state agency that also disciplines physicians. Of the physicians who enrolled in this program, 72% have completed it successfully. A total of 618 physicians have been accepted into the program since its inception, with 247 physicians currently participating.

California↗
PubMed1990

[Treatment with extracorporeal shockwave lithotripsy (ESWL), endourology and dissolution for staghorn calculi composed of cystine: report of two cases].

Two cases of complete staghorn calculi composed of cystine that were treated with ESWL, endourology and dissolution are reported. After successful dissolution in vitro using tromethamine (pH 8-10), the same solution was used to irrigate the renal collecting system via nephrostomy tube for residual fragments after ESWL and/or endourology. One patient was treated with dissolution for 60 days, the other patient for 6 days. After this therapy, these patients became almost stone-free. Our experience demonstrates that the residual fragments after ESWL and/or endourology with staghorn calculi composed of cystine can be dissolved by tromethamine.

Adult↗
PubMed1989

Biosynthesis and secretion of pullulanase, a lipoprotein from Klebsiella aerogenes.

We constructed, by site-directed mutagenesis, a mutant pullulanase gene in which the cysteine residue in a pentapeptide sequence, Leu16-Leu-Ser-Gly-Cys20 within the NH2-terminal region of pullulanase from Klebsiella aerogenes, is replaced by serine (Ser20). The modification, processing, and subcellular localization of the mutant pullulanase were studied. Labeling studies with [3H]palmitate and immunoprecipitation with mouse antiserum raised against pullulanase showed that the wild form of both the extracellular and intracellular pullulanases contained lipids, whereas the mutant enzyme was not modified with lipids. Only the Cys20 was modified with glyceryl lipids. The bulk of the mutant pullulanase was located in the periplasm, but a portion of the unmodified, mutant pullulanase was secreted into the medium. Mutant pullulanases from the extracellular and the periplasm were purified and their NH2-terminal sequences were determined. Both the mutant pullulanases were cleaved between residues of Ser13 and Leu14 which is 6-amino acid residues upstream of the lipid modified pullulanase cleavage site. This new cleavage was resistant to globomycin, an inhibitor of the prolipoprotein signal peptidase of Escherichia coli. These results indicate that the pentapeptide sequence plays an important role in maturation and translocation of pullulanase in K. aerogenes. However, the modification of pullulanase with lipids seems to be not essential for export of the enzyme across the outer membrane.

Amino Acid Sequence↗
PubMed1989

[Prophylaxis of recurrence of superficial bladder tumor by intravesical chemotherapy].

During the past 10 years, we have experienced 110 bladder tumor cases. Among them, 70 patients were diagnosed superficial bladder tumor. Of these 70 cases, 30 were treated with intravesical adriamycin (ADR) and peplomycin (PEP), 13 with ADR only and one case with PEP and remaining 26 with TUR and hydrostatic pressure technique. We studied the efficacy of combination intravesical chemotherapy with ADR and PEP and other treatments in the prevention of recurrence in the superficial bladder tumor cases. The recurrence rate during 3 years of each group, was 25% in the group treated with ADR and PEP, 35% with ADR and 55% in remaining group. 3 years recurrence rate in the group treated with ADR and PEP was significantly low than that in the group tread with TUR and hydrostatic pressure technique alone (Wilcoxon test). Side effects was pollakisuria, pain after micturition and others. Anaphylactic shock appeared in one case. From these results we concluded that intravesical chemotherapy with combined agents is more effective than that with a single one or no treatment after TUR.

Administration, Intravesical↗