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Biomedical subjects

S Imamura

Publications and source records attributed to S Imamura.

At least 523 records · Page 29Linked to original sources
PubMed1978

Severe erosive stomatitis and giant lymph node hyperplasia of retroperitoneum (Castleman's tumor).

A severe, extensive, erosive stomatitis developed in a 33-year-old Japanese man who had had intraperitoneal giant lymph node hyperplasia (Castleman's tumor) of the hyaline-vascular type. Histologically, there was a dense lymphoid cell infiltration in the dermis with invasion of the mucosal epithelium. It was hypothesized that an autoaggressive attack of lymphoid cells against the epithelium of the oral mucosa played a role in the pathogenesis of this erosive stomatitis and it was suggested that there might be a correlation between the occurrence of stomatitis and the presence of Castleman's tumor.

Adult↗
PubMed1978

Enzyme immunoassay of human chorionic gonadotropin employing beta-galactosidase as label.

An enzyme-linked immunoassay was applied to the determination of hCG, a glycoprotein hormone usually assayed by RIA. For this purpose, an enzyme hormone conjugate was prepared by reacting hCG with beta-D-galactosidase (beta-Gal.) of E. coli in the presence of N-(m-maleimidobenzoyloxy) succinimide (MBS) as coupling reagent. The conjugate, after purification by affinity and gel chromatographies, was shown to exhibit sufficient enzyme activity and immunoactivity. The immunoassay of hCG was performed by the double antibody method and, using this assay, 0.4-250 mIU/ml hCG were detectable. This was about 10 times as sensitive as the RIA. Difficulty was experienced when this method was utilized for the determination of hCG in plasma samples from patients. Since the presence of the plasma may have affected this assay method, the following improvements were made: 1) the same volume of hormone-free plasma was added to the standard solutions of hCG, and 2) the volume of plasma sample was 10 microliter. The performance and validity of this assay were comparable to the RIA using [125I]hCG as tracer. The dose-response curves of both assay have the same slope and there was no significant difference between the values (correlation coefficient, Y = 0.96X + 1.53).

Acylation↗
PubMed1977

Fisher's syndrome: a pharmacological study of the pupils.

A pharmacological study was performed in the involved pupils to demonstrate the site of lesion in a patient with Fisher's syndrome who showed marked ptosis, complete external ophthalmoplegia, pupillary involvement with anisocoria, facial paresis, ataxia, areflexia, and albuminocytological dissociation in the cerebrospinal fluid. The instillation of 2.5% methacholine produced mild constriction of one pupil. This response was not detectable in the recovery stage. The instillation of 1.25% l-epinephrine produced marked bilateral dilation of the pupils, in both the early and recovery stages. Instillation of 5% tyramine produced pupillary dilation as in the normal pupil. The response to 5% cocaine, tested only in the recovery stage, was weak in one pupil. These results imply that the pupillary involvement was due to peripheral involvement of the sympathetic and parasympathetic nervous systems. The lesion in the sympathetic nervous system was preganglionic, but in the parasympathetic nervous system the precise localization could not be determined.

Aged↗
PubMed1977

Purification of lipase from Chromobacterium viscosum by chromatography on palmitoyl cellulose.

Palmitoyl cellulose was used to adsorb the extracellular lipase [triacylglycerol acyl-hydrolase EC 3.1.1.3] of Chromobacterium viscosum from crude enzyme solution, and the adsorbed enzyme was eluted with a suitable detergent, such as Adekatol 45-S-8 or Triton X-100. The enzyme was then purified by chromatography on a palmitoylated gauze column with an overall recovery of 71% and an increase in the specific activity of 11-fold from the supernatant fluid of bacterial cultures. Further purification procedures included fractionation with acetone, and chromatography on Sephadex G-150 and G-75 columns. Two isoenzymes were obtained, each in a homogeneous state on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis: one had a molecular weight of 120,000 and pI of 3.7 and the other a molecular weight of 30,000 with a pI of 7.3.

Cellulose↗
PubMed1977

Oxidative pathway of choline to betaine in the soluble fraction prepared from Arthrobacter globiformis.

One strain of bacteria which showed high H2O2-generating activity was isolated from soil and characterized as Arthrobacter globiformis based on its morphological, nutritional, and physiological characteristics. The activities of H2O2 generation, NAD reduction and oxygen consumption in the bacterial cells were examined using choline, betaine aldehyde or betaine as substrate. Choline was oxidized to betaine aldehyde under aerobic conditions in a reaction coupled with H2O2 generation and oxygen consumption. On the other hand, betaine aldehyde seemed to be oxidized to betaine through two distinct oxidative reactions, H2O2 generation (oxygen consumption) under aerobic conditions and NAD reduction under either aerobic or anaerobic conditions. These enzyme activities were found in the supernatant fraction of the sonicated cell preparation.

Aldehydes↗
PubMed1977

Purification and characterization of choline oxidase from Arthrobacter globiformis.

Choline oxidase was purified from the cells of Arthrobacter globiformis by fractionations with acetone and ammonium sulfate, and column chromatographies on DEAE-cellulose and on Sephadex G-200. The purified enzyme preparation appeared homogeneous on disc gel electrophoresis. The enzyme was a flavoprotein having a molecular weight of approx. 83,000 (gel filtration) or approx. 71,000 (sodium dodecyl sulfate--polyacrylamide disc gel electrophoresis) and an isoelectric point (pI) around pH 4.5. Identification of the reaction products showed that the enzyme catalyzed the following reactions: choline + O2 leads to betaine aldehyde + H2O2, betaine aldehyde + O2 + H2O leads to betaine + H2O2. The enzyme was highly specific for choline and betaine aldehyde (relative reaction velocities: choline, 100%; betaine aldehyde, 46%; N,N-dimethylaminoethanol, 5.2%; triethanolamine, 2.6%; diethanolamine, 0.8%; monoethanolamine, N-methylaminoethanol, methanol, ethanol, propanol, formaldehyde, acetaldehyde, and propionaldehyde, 0%). Its Km values were 1.2 mM for choline and 8.7 mM for betaine aldehyde. The optimum pH for the enzymic reaction was around pH 7.5.

Alcohol Oxidoreductases↗
PubMed1977

Experimental production of rabbit anti-guinea-pig epidermal cell sera. Comparison to pemphigus antibodies.

Anti-epidermal cell sera (AES) were obtained by immunizing rabbits with enzymatically dispersed, viable guinea-pig epidermal cells followed by absorption with guinea-pig red blood cells, spleen and thymus cells, and liver powders. Complement-mediated cytotoxicity and immunofluorescence demonstrated that AES were towards cell surface antigen specific for stratified squamous epithelia of guinea pigs, and cross reacted with the corresponding tissues of humans and monkeys. Immunofluorescence revealed that AES reacted with Hassall's corpuscles and surrounding epithelial cells of the guinea-pig thympus which seemed to share common antigens with the epidermis; AES gave no reaction with other organs. While antigens reactive with pemphigus antibodies (PA) were demonstrated by membrane immunofluorescence to be present on the epidermal cell surface, PA showed no cytotoxicity to guinea-pig and human epidermal cells. Re-treatment of isolated epidermal cells with trypsin showed that antigens ractive with PA were more susceptible to the enzyme than those reactive with AES. These findings suggest that the cell surface antigens binding AES are different from the antigens which bind PA.

Animals↗
PubMed1977

Antibody titer and clinical course of pemphigus.

The relationship between the titer of pemphigus antibody and the clinical course of the disease was investigated in 15 patients with various types of pemphigus. Although antibody titers generally ran parallel to fluctuations of the clinical course, the elevation of antibody titer appeared to follow the re-appearance or exacerbation of the lesions on 10 occasions in 6 patients, while it appeared to precede the latter only on 2 occasions in 2 patients. In addition, the disappearance of the antibody was considerably delayed after disappearance of skin lesions in 2 cases. These findings suggest that the pemphigus antibody is the result of skin damage, rather than the cause of pemphigus itself.

Adult↗
PubMed1977

Quantitative determination of hippuric and m-methylhippuric acids in urine by high-speed liquid chromatography.

High-speed liquid chromatography employing an ultraviolet photometric detector has been applied to the simultaneous determination of hippuric and m-methylhippuric acids in urine. Reversed-phase partition chromatography is carried out on a muBondapak C18 column with methanol-water as the eluent system. This method obviates the necessity for isolation or reaction of these acids before assay. The only pretreatment necessary is extraction of sample with ethyl acetate. A linear relationship is obtained between the peak heights and the hippuric or m-methylhippuric acid concentrations. Mean recovery of hippuric and m-methylhippuric acids in urine is 99.8% and 99.3% respectively. The determination of hippuric acid by this method gives lower concentrations in normal urine than does the colorimetric method of Umberger and Fiorese (1963).

Chromatography, High Pressure Liquid↗
PubMed1977

Demonstration of epidermis-specific heteroantigens in thymic epithelial cells.

Heterologous anti-epidermal cell serum was obtained by immunizing rabbits with enzymatically dispersed, viable epidermal cells of guinea pigs, followed by absorption of the antiserum with red blood cells (sheep and guinea pig), lymphoid cells and liver powder (guinea pig). Immunofluorescence demonstrated that the antiserum reacted specifically with stratified squamous epithelial cells and thymus epithelial cells including Hassall's bodies of the guinea pig, monkey and man. It is suggested that the epithelial cells of the skin and thymus have common heteroantigens.

Animals↗
PubMed1977

Papular dermatitis herpetiformis. Report of a case with localized, facial lesions.

A male patient with unusual clinical features of dermatitis herpetiformis is reported. The eruption consisting mainly of erythematous papules developed symmetrically around the mouth and later around the eyes, and has been circumscribed within these areas for 4 years. The dermatitis herpetiformis nature of the lesion was confirmed by direct immunofluorescent testing.

Adult↗