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Biomedical subjects

H Shirai

Publications and source records attributed to H Shirai.

At least 91 records · Page 5Linked to original sources
PubMed1993

Detection of cholera toxin gene in stool specimens by polymerase chain reaction: comparison with bead enzyme-linked immunosorbent assay and culture method for laboratory diagnosis of cholera.

Stool specimens obtained from 123 hospitalized patients with acute secretory diarrhea admitted to the Infectious Diseases Hospital, Calcutta, India, were examined for isolation of Vibrio cholerae O1 by direct or enrichment plating on selective media for cholera toxin (CT) by bead enzyme-linked immunosorbent assay (bead-ELISA) and for the CT gene by polymerase chain reaction (PCR). V. cholerae O1 was isolated either by direct culture or by enrichment culture from 70 stool specimens, all of which gave positive results by PCR. Eleven specimens which were culture negative and bead-ELISA positive also gave positive results by PCR. In addition, 13 more specimens which were negative by both the culture method and bead-ELISA, were positive by PCR. With the combined results of both the culture method and the CT bead-ELISA, a confirmed laboratory diagnosis of cholera could be made from 81 stool specimens, while the combined results of the three methods, including PCR, yielded a positive result for 94 specimens examined. From these data, we conclude that PCR provides a more sensitive and specific assay for rapid diagnosis of cholera than currently available methods.

Adult↗
PubMed1993

Immunosuppressive factors detected during convalescence in a patient with severe serum sickness induced by carbamazepine.

We report on a patient with severe serum sickness induced by carbamazepine in whom anticarbamazepine IgG antibodies were detected in the serum. The T cells of the patient showed impairment of phytohemagglutinin-induced proliferation, and hypergammaglobulinemia was evident. The clinical features and immunological abnormalities were compatible with immunoblastic lymphadenopathy. Immunosuppressive factors were also detected in the patient. Their molecular weights ranged from 20,000 to 30,000 as evaluated by Sephadex G-200 gel filtration. Such immunosuppressive cytokines were not detected in other patients with carbamazepine allergy who did not develop the clinical manifestations of immunoblastic lymphadenopathy. These results suggest that the T cell functional deficiency of immunoblastic lymphadenopathy is induced by these immunosuppressive cytokines.

Carbamazepine↗
PubMed1993

Construction of sandwich enzyme immunoassay for rat transthyretin using recombinant antigen approach, and its application.

A sandwich enzyme immunoassay for rat transthyretin using a recombinant antigen approach is described. Rat transthyretin cDNA was cloned by PCR. Rat transthyretin fused with the IgG-binding ZZ domain of protein A was expressed in E. coli using the fusion vector pEZZ18. Antibody against the fusion protein was specific to rat transthyretin in plasma as shown by immunoblotting. Affinity-purified anti-rat transthyretin-ZZ was biotinylated and used for the sandwich enzyme immunoassay. In this assay, the measurable range was 1.2-50 ng/ml and the coefficients of variation within and between the assay series (assay range: 2.5-20 ng/ml) were 1.31 +/- 0.08% and 3.50 +/- 1.46%, respectively. Cross-reactivity was examined using bovine, human, and mouse serum. There was a cross-reaction only with mouse transthyretin. In an in vitro experiment, transthyretin secreted by rat hepatocytes could be measured by the sandwich enzyme immunoassay.

Amino Acid Sequence↗
PubMed1992

An immunodominant haptenic epitope of carbamazepine detected in serum from patients given long-term treatment with carbamazepine without allergic reaction.

An anticarbamazepine antibody was detected in the serum of a patient with severe carbamazepine-induced serum sickness. We found that the patient's T cells and IgG antibody recognized an epitope which appeared in subjects showing an allergic reaction, as well as that in subjects who showed no allergic reaction, after long-term carbamazepine therapy. These results show that an anti-carbamazepine immune response does not occur in the majority of subjects who undergo long-term carbamazepine therapy without developing allergic symptoms, although the immunodominant haptenic epitope of carbamazepine is present in their sera.

Carbamazepine↗
PubMed1992

A new series of natural antifungals that inhibit P450 lanosterol C-14 demethylase. I. Taxonomy, fermentation, isolation and structural elucidation.

A new series of antifungal antibiotics, Ro 09-1470 and its 6 congeners were isolated from the fermentation broth of Penicillium sp. NR6564. Their structures were determined as tetrahydropyran derivatives with an alkenyl side chain on the basis of their spectroscopic and physico-chemical properties. Among these compounds, Ro 09-1470 and Ro 09-1545 possessing a glycyl N-substituted glycyl ester residue had high antifungal activity. Ro 09-1469, one of the congeners, was found in the fermentation broth of several strains of Aspergillus sclerotiorum Huber.

Antifungal Agents↗
PubMed1992

[Visual field change and risk factors for progression of visual field damage in low tension glaucoma].

The authors carried out a prospective study in an attempt to determine the possible effect of intraocular pressure (IOP) and some clinical factors on the clinical course of low tension glaucoma (LTG). During the study period all the patients were followed without any antiglaucoma medication. The enrollment criteria for the study were reproducible, mild to moderate field loss as defined as a mean defect (MD) of greater than 2 dB and less than 10 dB or corrected loss variance (CLV) of greater than 7 dB revealed by the Octopus 201, G1 program. Forty-two consecutive patients (56 eyes) who fulfilled this criteria were enrolled. Baseline and follow-up examinations included applanation tonometry, perimetry with G1 program, blood pressure and pulse rate. When the MD increased by 4 dB or more on two consecutive perimetry examinations, the field defect was judged as "progressed". During the follow-up period (6-51 months, 25.1 +/- 12.5 months), the field defect progressed in 14 eyes of 12 patients. The life-table analysis (Kaplan-Meier) revealed that the rate of nonprogression of visual field defects was 55.5% at 48 months. The rate of nonprogression was significantly lower in 16 eyes with a mean IOP equal to or higher than 15 mmHg as opposed to 40 eyes with that lower than 15 mmHg (34.3% and 67.2% respectively, p less than 0.05). The results seem to indicate that IOP is likely to be responsible for the aggravation of visual fields in LTG. Canonical discriminant analysis revealed that the discriminant function containing four variables gives the best separation between the "progressed" and "nonprogressed" group (discriminant efficacy: 83.9%).

Adult↗
PubMed1991

Analysis of the gene of Vibrio hollisae encoding the hemolysin similar to the thermostable direct hemolysin of Vibrio parahaemolyticus.

The gene (designated as Vh-tdh) of Vibrio hollisae 9041 encoding a hemolysin similar to the thermostable direct hemolysin (TDH) of V. parahaemolyticus contained a 567-base-pair open reading frame (ORF), which was 93.3-93.5% homologous to those of the tdh genes of V. parahaemolyticus, V. cholerae non-01, and V. mimicus encoding TDH or similar hemolysins. Comparative analysis of the nucleotide sequence containing the Vh-tdh ORF with published nucleotide and amino acid sequences suggested that the Vh-tdh gene and other tdh genes diverged from a common ancestral gene, that the divergence was closely associated with the evolutionary divergence of V. hollisae from other species of genus Vibrio, and that strain-to-strain variation of the Vh-tdh gene exists in V. hollisae.

Amino Acid Sequence↗
PubMed1991

Similarity of the tdh gene-bearing plasmids of Vibrio cholerae non-O1 and Vibrio parahaemolyticus.

The gene encoding a hemolysin similar to the thermostable direct hemolysin (TDH) of Vibrio parahaemolyticus was previously cloned from a plasmid of Vibrio cholerae non-O1. The gene (designated as NAG-tdh) was subcloned and its nucleotide sequence was determined and compared with reported sequences of the four tdh gene copies encoding TDH, of which three were cloned from the chromosome and one was cloned from a plasmid of V. parahaemolyticus. In the coding region, the NAG-tdh gene had 100% homology with the plasmid-borne tdh gene (tdh4) whereas the NAG-tdh gene was 96.7-98.6% homologous to the three chromosomal tdh genes. The sequences of the NAG-tdh and tdh4 genes were nearly identical in the further upstream and downstream regions. The entire plasmids carrying the two tdh genes were found to be highly homologous when compared by restriction endonuclease and Southern blot analyses. The results suggest that the tdh gene has been transferred between V. cholerae non-O1 and V. parahaemolyticus by a plasmid, directly or indirectly, and that the nucleotide sequences of the tdh gene-bearing plasmids have undergone minor base changes in the respective genetic backgrounds.

Amino Acid Sequence↗
PubMed1991

Analysis of the tdh gene cloned from a tdh gene- and trh gene-positive strain of Vibrio parahaemolyticus.

A variant of the gene (tdh) encoding thermostable direct hemolysin (TDH) was cloned from the chromosome of Vibrio parahaemolyticus AQ3860, which gave positive results in the hybridization tests with the tdh gene probe and the trh (tdh-related hemolysin) gene probe and showed a low level of reaction in an enzyme-linked immunosorbent assay for TDH. Nucleotide sequence analysis of the cloned gene (tdh5) provided no evidence that tdh5 is evolutionally closer to the trh gene than the other tdh genes. The tdh5 gene was flanked by 40 base-pair sequences constituting perfect inverted repeats, which may suggest association of the tdh5 gene with insertion sequence-like structure. These results suggest that the tdh5 gene and the trh gene were not originally produced by gene duplication in AQ3860 but rather that one of the two genes moved into AQ3860 from an external source.

Animals↗
PubMed1991

Evidence for insertion sequence-mediated spread of the thermostable direct hemolysin gene among Vibrio species.

The tdh gene of Vibrio parahaemolyticus which encodes the thermostable direct hemolysin has been found in some strains of other Vibrio species. Analysis of seven tdh genes cloned from V. parahaemolyticus, Vibrio mimicus, and non-O1 Vibrio cholerae revealed that all tdh genes were flanked by insertion sequence-like elements (collectively named ISVs) or related sequences derived from genetic rearrangement of ISVs. The ISVs possessed 18-bp terminal inverted repeats highly homologous to those of IS903 (2- to 4-bp mismatch) and were 881 to 1,058 bp long with less than 33.6% sequence divergence. These features and nucleotide sequence similarities among ISVs and IS903 (overall homologies between ISVs and IS903, ca. 50%) strongly suggest that they were derived from a common ancestral sequence. A family of ISVs were widely distributed in Vibrio species, often regardless of the possession of the tdh genes, and one to several copies of the ISVs per organism were detected. A strain of V. mimicus possessed two copies of the ISVs flanking the tdh gene and three copies unrelated to the tdh gene. However, the transposition activity of the ISVs could not be demonstrated, probably because they had suffered from base changes and insertions and deletions within the transposase gene. The possible mode of ISV-mediated spread of the tdh gene is discussed from an evolutionary standpoint.

Bacterial Toxins↗
PubMed1991

Polymerase chain reaction for detection of the cholera enterotoxin operon of Vibrio cholerae.

We report a set of oligonucleotide primers and amplification conditions for the polymerase chain reaction to detect the ctx operon of Vibrio cholerae. The results of this assay on strains of V. cholerae and related organisms were identical with those obtained by the DNA colony hybridization test with the polynucleotide probe. The detection limit of this system was 1 pg of chromosomal DNA or broth culture containing three viable cells. The polymerase chain reaction method could directly detect the ctx operon sequences in rice-water stool samples from patients with cholera.

Base Sequence↗
PubMed1991

Anticarbamazepine antibody induced by carbamazepine in a patient with severe serum sickness.

Anticarbamazepine antibody was detected in a patient who had clinical signs of serum sickness induced by carbamazepine. Skin rash, fever, oedema, and lymphadenopathy are classic signs of severe adverse reaction, but although immunological hypersensitivity is thought to be a contributory factor, the presence of anticarbamazepine antibody has not previously been reported to our knowledge.

Animals↗
PubMed1991

Structural studies on avidinorubicin, a novel anthracycline with platelet aggregation inhibitory activity.

Avidinorubicin (MW 1,214, C60H86N4O22) was isolated from the cultured broth of strain NR0576 (which was identified as Streptomyces avidinii Stapley et al.) by butyl alcohol extraction, Sephadex LH-20 column chromatography and preparative HPLC. Avidinorubicin inhibited thrombin-induced platelet aggregation with an IC50 being 7.9 microM and was determined to be a novel anthracycline possessing two units of a new aminosugar, avidinosamine, in place of two decilonitrose groups in decilorubicin.

Anthracyclines↗
PubMed1991

[The effects of lowering of blood pressure on pain sensitivity in spontaneously hypertensive rats].

It has been reported that elevation of blood pressure produces a reduction in pain sensitivity. This study was designed to clarify the correlation in spontaneously hypertensive rats (SHR) between fall in blood pressure and pain sensitivity. In seven-weeks-old male SHR, the angiotensin converting inhibitor delapril (10 mg/kg/day) or calcium antagonist nifedipine (3 mg/kg/day) was administered orally every day for 8 weeks. Systolic blood pressure (SBP) pretreatment was significantly higher in the SHR than in normotensive Wistar-Kyoto (WKY) rats and pain sensitivity measured with the hot plate method was significantly lower in the SHR than in the WKY rats. Administration of both drugs produced a significant suppression of elevation of SBP, and produced a significant elevation of pain sensitivity. Furthermore, at 8 weeks after drug administration, urinary norepinephrine (UNE) significantly decreased and plasma beta-endorphin (beta-end) significantly increased. A significant correlation was noted between pain sensitivity and SBP and also between pain sensitivity and UNE. Of these, pain sensitivity was the more closely correlated to degree of change in UNE than to degree of change in SBP. It appears that elevation of pain sensitivity is due to suppression of the sympathetic nervous system by antihypertensive drugs, but not to elevation of beta-end levels. These data suggest that a fall in blood pressure through administration of delapril or nifedipine reverses decrease in pain sensitivity in SHR and that decrease in sympathetic tone plays an important role in the restoration of levels of sensitivity to pain.

Animals↗
PubMed1990

Nucleotide sequence of the thermostable direct hemolysin gene (tdh gene) of Vibrio mimicus and its evolutionary relationship with the tdh genes of Vibrio parahaemolyticus.

The gene encoding a hemolysin similar to the thermostable direct hemolysin (TDH) of Vibrio parahaemolyticus was previously cloned from the chromosome of Vibrio mimicus. The nucleotide sequence of the hemolysin gene was determined in this study. The gene proved to be a variant of the thermostable direct hemolysin gene (tdh gene) and was designated as Vm-tdh because the sequence divergences between the Vm-tdh gene and four tdh genes of V. parahaemolyticus were 2.1-3.0%, while the sequence divergences among the four tdh genes of V. parahaemolyticus ranged between 1.4 and 3.3%. Analysis of these five tdh genes revealed that they evolved from a common ancestor in discrete and understandable order by sporadic base substitutions.

Base Sequence↗