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Biomedical subjects

M Homma

Publications and source records attributed to M Homma.

At least 181 records · Page 10Linked to original sources
PubMed1992

Enteric adenovirus type 41 isolates: cloning, physical maps and diversity in restriction enzyme cleavage pattern.

Adenovirus (Ad) type 40 and 41 DNAs were directly extracted from stool specimens of children with gastroenteritis. Two new strains of Ad41, Sanekata and Ehime strain, were cloned and their restriction maps were constructed. The left terminal end of the cloned Ad41 genome, EcoRI-E fragment of the Sanekata strain and EcoRI-F fragment of the Ehime strain, had transforming ability in rat 3Y1 cells. Only one of the 35 isolates of Ad40 tested showed a different restriction profile, while three different restriction profiles were found in DNAs from Ad41 isolates.

Adenovirus Infections, Human↗
PubMed1992

Identification of Candida albicans antigens reactive with immunoglobulin E antibody of human sera.

Candida albicans antigens which reacted with immunoglobulin E (IgE) antibodies of 57 allergic patients were detected by immunoblotting. Of the various antigens, the 175-, 125-, 46-, 43-, and 37-kDa antigenic components reacted most frequently with the patient sera. To purify the major antigens, C. albicans cells were fractionated. The 46-, 43-, and 37-kDa antigens were recovered in cytoplasmic fractions, but the 175- and 125-kDa antigens were not recovered in any fraction. The 46-, 43-, and 37-kDa antigens were purified from cytoplasmic fractions by DEAE and P11 ion-exchange chromatography. Antigens were isolated by cutting bands out of sodium dodecyl sulfate-polyacrylamide gels. The purified components confirmed by immunoblotting were next processed for amino acid sequencing. Parts of the sequences of the 46-, 43-, and 37-kDa antigens had significant levels of homology with Saccharomyces cerevisiae glycolytic enzyme enolase, phosphoglycerate kinase, and aldolase, respectively. Rabbit IgG antibodies prepared against the 46- and 43-kDa antigens strongly cross-reacted with the homologous proteins of S. cerevisiae. However, S. cerevisiae enolase and phosphoglycerate kinase did not cross-react with IgE of patient sera. This result suggests that IgE antibodies against only small parts of their epitopes are elevated in the allergic patients. Since enolase is reported to be a major antigen for systemic candidiasis, this enzyme may be the immunodominant protein in both allergies and fungal infections.

Adolescent↗
PubMed1992

Glucocorticoid receptor and inhibition of 3-O-methyl-D-glucose uptake by glucocorticoids in peripheral blood leukocytes from normal humans: correlation between receptor level and hormone effect in vitro.

We have measured the glucocorticoid receptor concentration in mononuclear and polymorphonuclear leukocytes, both of which were isolated from peripheral blood from ten healthy male volunteers. In parallel, the inhibitory effect of dexamethasone on 3-O-methyl-D-glucose uptake was assayed in the corresponding mononuclear leukocytes. The glucocorticoid receptor levels in mononuclear leukocytes correlated with those in polymorphonuclear leukocytes, and there was a linear relationship between the cellular glucocorticoid receptor levels and glucocorticoid-mediated inhibition of the uptake of 3-O-methyl-D-glucose in mononuclear leukocytes. When mononuclear leukocytes were incubated in the presence of 8-bromo-cAMP, cellular glucocorticoid receptor levels increased and a more pronounced inhibitory effect of dexamethasone was observed on the transport of 3-O-methyl-D-glucose. We conclude that the cellular glucocorticoid receptor levels in peripheral blood leukocytes reflect in vitro responsiveness to glucocorticoids in mononuclear leukocytes from healthy males, and that the individual responsiveness may alter upon changes in the cellular levels of glucocorticoid receptor.

3-O-Methylglucose↗
PubMed1992

[Bronchial asthma].

In the first study, to clarify whether increased vagal afferent activity contributes to the increase in ventilatory response to CO2 in patients with asthma, we examined the effects of prostaglandin E2 (PGE2) inhalation on the respiratory response to CO2 in seven normal subjects. After PGE2 inhalation, the ventilatory and occlusion pressure responses to CO2 increased significantly compared with those after saline inhalation, with no increase in respiratory resistance. These results suggest that increase in vagal afferent activity may play a role in the increased hypercapnic response during acute exacerbations of asthma. In the second study, to clarify the reduced respiratory chemosensitivity associated with asthma-related deaths, we examined the hypercapnic and hypoxic ventilatory responses in five patients with near-fatal asthma who were given artificial ventilation and/or became unconsciousness during an acute exacerbation of asthma. Hypoxic ventilatory response was significantly lower in these subjects than in patients with uncomplicated asthma and normal subjects, suggesting that lowered hypoxic ventilatory response may be related to death from asthma.

Asthma↗
PubMed1992

Glucocorticoid receptor in patients with lupus nephritis: relationship between receptor levels in mononuclear leukocytes and effect of glucocorticoid therapy.

We investigated the clinical significance of glucocorticoid receptor determination in 20 patients with systemic lupus erythematosus (SLE) who afterwards developed nephrotic syndrome. Glucocorticoid receptor concentrations in mononuclear leukocytes (MNL) in these patients were comparable with those in both other patients with SLE and healthy persons. Improvement in urinary protein excretion and in disease activity, which was scored according to the SLE Disease Activity Index system of the University of Toronto, closely related to the glucocorticoid receptor concentrations in MNL isolated from the corresponding patients. In summary, glucocorticoid receptor determination in patients with lupus nephritis may be a predictive clue for assessing responsiveness to glucocorticoid therapy.

Adolescent↗
PubMed1992

Practical applications in molecular biology of sensitive fluorescence detection by a laser-excited fluorescence image analyzer.

A new kind of fluorescence image analyzer was developed for a variety of uses, especially in molecular biology. Compounds labeled with fluorescent groups on a gel or nitrocellulose membrane are excited with 532 nm of light from a green laser. The fluorescence emitted passes through light-collecting fibers to a photomultiplier. Imaging data converted from the emitted light are analyzed by a microcomputer and stored on a magnetic optical disk. Dideoxy DNA sequencing was done with the same amount of DNA used for autoradiography, and the sequencing ladders obtained from gel scanning were automatically converted to sequence data by the analyzer. When an agarose gel was analyzed after electrophoresis, DNA stained with ethidium bromide was detected by the analyzer with higher sensitivity rather than by the conventional photographic method. Nylon and nitrocellulose membranes could be read by the analyzer, so blot hybridization experiments can be done without radioisotopes. High-quality computer storage of the imaging data from gel electrophoresis and hybridized membranes, including pulsed-field gels, make it possible to quantify image intensity and to construct many kinds of databases.

Base Sequence↗
PubMed1991

Simple and accurate determination of methylpyrazines in biofluids using high-performance liquid chromatography.

The determination of six methylpyrazines was performed using high-performance liquid chromatography (HPLC). Methylpyrazines were simultaneously extracted and injected onto a silica gel column with a syringe-type minicolumn packed with diatomaceous earth granules. The extraction-injection solvent used was dichloromethane and the mobile phase solvent for HPLC was dichloromethane containing 0.08% of 1.65 M ammonia solution and 0.5% of methanol. Methylpyrazines were detected using an ultraviolet detector set at 275 nm. Linear relationships between the amount of sample and peak height were confirmed from 50 ng/ml to 10 micrograms/ml of the biofluids. When an aliquot of 10 microliters of biofluid was introduced to the minicolumn, the detection limit of methylpyrazines was as low as 30 ng/ml with each pyrazine derivative. The method is simple and accurate and is thus applicable to pharmacokinetic studies which are performed on animals. The results showed that the possible pharmacological effects of methylpyrazines might be evaluated pharmacokinetically using this newly developed technique.

Animals↗
PubMed1991

pH-dependent column fractionation for characterization of endogenous digoxin-like immunoreactive factors in pregnant urine.

Samples of pregnant urine were treated with three diatomaceous earth columns to fractionate organic solvent-soluble components. The first column was pre-injected with the urine sample. The second and the third columns were pre-injected with sodium bicarbonate and sodium hydroxide solutions, respectively; these played an important role in capturing acidic components in the urine extract from the first column. Neutral components could be eluted out from the columns with the organic solvent, while the basic components were retained in the first column. Once strongly and weakly acidic components were captured on the alkaline columns, they were separately treated with an acidic mobile phase and recovered. The digoxin-like activities of each fraction were examined for cross-reactivity to antidigoxin antibody and inhibitory effects on dog kidney Na+, K(+)-ATPase. Both types of reactivity were found in all three fractions and decreased in the following order: strongly acidic, neutral and weakly acidic. The neutral fraction of pregnant urine showed significantly greater cross-reactivity than that of the non-pregnant urine. Following hydrolysis of the pregnant urine with beta-D-glucuronidase, the cross-reactivity of the neutral fraction increased significantly. High performance liquid chromatographic analysis showed that several components in the neutral fraction had apparently increased after the hydrolysis, showing the possible presence of unknown digoxin-like components in the pregnant urine.

Antibodies↗
PubMed1991

Characterization of Ac1-Proteinase from the venom of Agkistrodon acutus (Hundred-pace snake) from Taiwan.

1. Ac1-Proteinase from the venom of Agkistrodon acutus was isolated in a homogeneous form by a previously published method. 2. Ac1-Proteinase possessed lethal, hemorrhagic, caseinolytic, azocaseinolytic, azoalbumin hydrolytic and hide powder azure hydrolytic activities. 3. The toxin also hydrolyzed the oxidized B chain of insulin and fibrinogen. The cleavage sites in the oxidized B chain of insulin were identified as Ala(14)-Leu(15) and Tyr(16)-Leu(17). The A alpha chain of fibrinogen was digested. 4. Biological properties of Ac1-Proteinase were investigated further and are reported in this paper.

Amino Acid Sequence↗
PubMed1991

Ion-sparing diuresis by 2,3-dibenzylbutane-1,4-diol, a synthetic mammalian-lignan derivative.

Diuretic properties of a synthetic lignan, 2,3-dibenzylbutane-1,4-diol (hattalin), and a naturally occurring arctigenin were examined in BALB/c male mice and Wistar male rats. Intra peritoneal administration of hattalin (50 mg/kg) in mice increased urine volume by 1.7-3.1 fold that of placebo-treated animals 40-260 min after administration (p less than 0.05 vs control). In contrast, 100 mg/kg of arctigenin had no effect on urine volume in mice. Hattalin (100 mg/kg), arctigenin (100 mg/kg), or furosemide (50 mg/kg) as a positive control was administered orally to rats, and accumulated urine volume was measured for up to 6-12 h. The urine volume of animals administered with hattalin showed 1.4-1.5 fold that of placebo-treated animals after 2-6 h of administration (P less than 0.05, n = 10). On the other hand, arctigenin showed no significant effect on urine volume for up to 12 h after administration (n = 8). The urine volume in animals administered with furosemide (n = 10) was 2.0-3.0 fold that of placebo-treated animals (P less than 0.01). Furosemide increased total Na+, K+, or Cl- excretion by 1.9, 1.8 or 2.2 fold, respectively, when compared with placebo-treated controls (P less than 0.01), whereas hattalin decreased Na+ excretion by 3.6 times (P less than 0.01), K+ excretion by 1.4 times (not significant), and Cl- excretion by 3.1 times (P less than 0.01). Serum Na+ and K+ levels did not change in both furosemide- and hattalin-administered rats, however, serum Cl- levels in these animals significantly decreased (P less than 0.01) when compared with controls. The results suggest that the diuretic property of hattalin is due to a novel mechanism which is different from that of furosemide or other diuretics modifying the ion-exchange at the uriniferous tubules.

Animals↗
PubMed1991

Prevalence of antibody to influenza C virus among pigs in Hyogo Prefecture, Japan.

The prevalence of influenza C virus among pigs in Hyogo Prefecture, Japan, was investigated by serological techniques. Out of 240 sera tested, 45 (19%) showed haemagglutination inhibition (HI) to influenza C virus. Pig sera with high HI titres also scored high in neutralization tests and ELISAs. When fractionated by sucrose density gradient ultracentrifugation, the HI/ELISA reactivities corresponded to antibodies of the IgM and IgG classes. Radioimmunoprecipitation tests revealed that some, but not all, of the pig sera with high HI activities precipitated HEF glycoprotein of influenza C virus. These results suggested that the HI activities of pig sera in Hyogo Prefecture were due to the presence of antibody to influenza C virus. Sera with IgM class antibody to influenza C virus were found throughout the year. However, the question of whether or not pigs serve as a natural reservoir for human influenza C virus still remains to be solved.

Animals↗
PubMed1991

Protection of mice by a protease inhibitor, aprotinin, against lethal Sendai virus pneumonia.

Proteolytic activation of Sendai virus in the lungs of mice is necessary to cause pneumopathogenicity. Using Sendai virus-infected lung block cultures, protease inhibitors were tested for their antiviral effect by examining inhibition of proteolytic activation. Among the inhibitors tested, a serine protease, aprotinin, was shown to be most effective. In vivo protection experiments demonstrated that aprotinin, when administered intranasally, could confer protection on mice against lethal Sendai virus pneumonia through the same mechanism as observed in the in vitro system. The present study provides an experimental basis for the use of protease inhibitors as antiviral drugs.

Animals↗
PubMed1991

Electrophoretic karyotypes of clinically isolated yeasts of Candida albicans and C. glabrata.

One-hundred-and-four isolates of yeast were collected from the vaginas of 97 outpatients. The isolates were identified by their characteristics in a carbohydrate assimilation test, a serological test and from their morphology. Candida albicans and Candida glabrata were the major isolates (75% and 20%, respectively). The karyotypes of the isolates were analysed by pulsed-field gel electrophoresis and almost all the karyotypes were distinguishable from one another when the band mobilities were carefully compared. Characteristics and karyotypes were not directly correlated, but seven C. albicans isolates (from six patients) had a common atypical karyotype and shared the same phenotype. These isolates are inferred to be generated by a wide genomic reorganization and mutation and the phenotypic changes may be advantageous for survival. The karyotypes of the isolates recovered from individual patients after intervals of 1-6 months were all identical except for one or two highly variable bands which were identified with an rDNA probe. This suggests that the variable bands are too variable to be useful for distinguishing strains, but from the patterns of the identical bands (i.e. except for the variable bands) we concluded that strains from individual patients do not change, at least over short periods. This, coupled with the extensive inter-isolate variability in karyotype, will be useful for Candida source determination and epidemiological studies.

Candida↗
PubMed1991

An indirect microhemagglutination test for Lyme disease.

We have developed an indirect microhemagglutination test (IMHA) for detecting antibodies to Borrelia burgdorferi using formalin-fixed chicken erythrocytes sensitized with a sonicated extract of the bacteria. The specificity of IMHA for Lyme disease was compared with that of a conventional indirect immunoperoxidase technique (IP) using sera from the patients with syphilis, randomly-chosen outpatients unrelated to Lyme disease, and from normal individuals. The IMHA was more specific than IP, giving little cross-reaction with syphilis. The IMHA also gave little background reactions with the sera of individuals unrelated to Lyme disease or syphilis. Therefore, the IMHA could be a useful test for the serodiagnosis of Lyme disease.

Antibodies, Bacterial↗
PubMed1991

Activation and suppression of a cryptic promoter in the intron of the human melanoma-associated ME491 antigen gene.

A deletion mutant of the human melanoma-associated ME491 antigen gene starting at the first intron (lambda R31) differentially mediates the antigen expression depending on the cell type. Cryptic promoter activity residing in a 270-base-pair (bp) fragment of the first intron was examined by primer extension analysis and recombinant chloramphenicol acetyltransferase (CAT) assay. The cryptic promoter, further localized within a 153-bp fragment (fr153BN), exerted its effect in Ltk- and H-ras-transformed NIH3T3 (3T3-Hras) but not in parental NIH3T3 cells. The results suggested that the cryptic promoter was associated with a novel ras-responsive positive regulatory element, since fr153BN did not contain an AP-1-binding sequence motif, known as the ras-responsive enhancer element. The cryptic promoter activity of fr153BN was suppressed by an upstream 121-bp fragment (fr121SB) which contained a consensus sequence motif for binding of a repressor protein, GC factor, and regions showing sequence similarity with putative cis-acting repressor elements found in the vimentin gene. The degree of the suppression was greater in 3T3-Hras than in Ltk- cells. These positive and negative regulatory elements may be differentially involved in the regulation of ME491 antigen expression depending on the cell type.

3T3 Cells↗
PubMed1991

Salmonella typhimurium mutants defective in flagellar filament regrowth and sequence similarity of FliI to F0F1, vacuolar, and archaebacterial ATPase subunits.

Many flagellar proteins are exported by a flagellum-specific export pathway. In an initial attempt to characterize the apparatus responsible for the process, we designed a simple assay to screen for mutants with export defects. Temperature-sensitive flagellar mutants of Salmonella typhimurium were grown at the permissive temperature (30 degrees C), shifted to the restrictive temperature (42 degrees C), and inspected in a light microscope. With the exception of switch mutants, they were fully motile. Next, cells grown at the permissive temperature had their flagellar filaments removed by shearing before the cells were shifted to the restrictive temperature. Most mutants were able to regrow filaments. However, flhA, fliH, fliI, and fliN mutants showed no or greatly reduced regrowth, suggesting that the corresponding gene products are involved in the process of flagellum-specific export. We describe here the sequences of fliH, fliI, and the adjacent gene, fliJ; they encode proteins with deduced molecular masses of 25,782, 49,208, and 17,302 Da, respectively. The deduced sequence of FliI shows significant similarity to the catalytic beta subunit of the bacterial F0F1 ATPase and to the catalytic subunits of vacuolar and archaebacterial ATPases; except for limited similarity in the motifs that constitute the nucleotide-binding or catalytic site, it appears unrelated to the E1E2 class of ATPases, to other proteins that mediate protein export, or to a variety of other ATP-utilizing enzymes. We hypothesize that FliI is either the catalytic subunit of a protein translocase for flagellum-specific export or a proton translocase involved in local circuits at the flagellum.

Amino Acid Sequence↗