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Biomedical subjects

T Mukai

Publications and source records attributed to T Mukai.

At least 127 records · Page 7Linked to original sources
PubMed1997

Collagen binding of Bifidobacterium adolescentis.

In this study, 13 bifidobacterial strains were tested for their ability to adhere to immobilized extracellular matrix (ECM) proteins. Only two Bifidobacterium adolescentis strains adhered to immobilized type I and type V collagens, but not to laminin, fibronectin, and type III and IV collagens. The adhesion of B. adolescentis BB-119 to type V collagen was inhibited by type I and V collagens and gelatin, and was diminished after protease treatment of the cells. Periodate treatment of immobilized collagen and the presence of galactose inhibited the adhesion of strain BB-119 to type V collagen. Two cell surface proteins with molecular masses of 36 kDa and 52 kDa from strain BB-119 were found to bind to horseradish peroxidase-conjugated type V collagen by ligand blotting. We concluded that B. adolescentis BB-119 binds to type V collagen at galactose chains as target via these two cell surface proteins by their lectin-like activity.

Bacterial Adhesion↗
PubMed1997

New p57KIP2 mutations in Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is characterized by numerous growth abnormalities and an increased risk of childhood tumors. The gene for BWS is localized in the 11p15.5 region, as determined by linkage analysis of autosomal dominant pedigrees. The increased maternal transmission pattern seen in the autosomal dominant-type pedigrees and the findings of paternal uniparental disomy reported for a subgroup of patients indicate that the gene for BWS is imprinted. Previously, we found p57KIP2, which is a Cdk-kinase inhibitor located at 11p15, is mutated in two BWS patients. Here, we screened for the mutation of the gene in 15 BWS patients.

Austria↗
PubMed1997

Distinct effects of MK-801 and (+/-)-2-amino-5-phosphonopentanoic acid on N-methyl-D-aspartate-induced rise of brain temperature in rats.

Intracerebroventricular (i.c.v.) administration of N-methyl-D-aspartate (NMDA) caused a biphasic rise of brain temperature, namely, a rapid, early rise and a larger, late rise, in urethane-anesthetized rats. I.c.v. pretreatment with a noncompetitive NMDA receptor antagonist, MK-801, attenuated the late rise of the brain temperature, but had no effect on the early rise, whereas i.c.v. pretreatment with a competitive NMDA receptor antagonist, (+/-)-2-amino-5-phosphonopentanoic acid (AP-5), attenuated both rises. AP-5 per se caused a rise in brain temperature without any rise of rectal temperature, whereas MK-801 per se caused no significant change of the brain or rectal temperature. This rise by AP-5 was suppressed by MK-801, suggesting an agonistic effect of AP-5 on NMDA receptors in rat brain in vivo.

2-Amino-5-phosphonovalerate↗
PubMed1997

Gastric corpus IL-8 concentration and neutrophil infiltration in duodenal ulcer patients.

BACKGROUND: The purpose of the present study was to examine the association between interleukin-8 (IL-8) in the gastric body due to Helicobacter pylori infection and histological gastritis, as well as elucidating the effect of acid secretion inhibitors on H. pylori associated body gastritis in duodenal ulcer patients. METHODS: Twenty H. pylori-negative patients, 20 H. pylori-positive patients with chronic gastritis without peptic ulceration, and 20 H. pylori-positive duodenal ulcer patients (DU) were studied. Four biopsy samples were taken, each from the greater curvature of the antrum and body of the stomach. Biopsies were histologically investigated by ELISA to determine the density of H. pylori, the degree of neutrophil infiltration and the IL-8 concentration in the mucosa. RESULTS: In the gastric mucosa of H. pylori-negative subjects, no IL-8 and hardly any neutrophil infiltration were observed. In contrast, enhanced IL-8 production and increased neutrophil infiltration were present in those infected with H. pylori. In H. pylori-positive patients, a significant correlation was observed between the IL-8 concentration and the degree of neutrophil infiltration, but no correlation was found in the body mucosa of those with DU. Twelve of 20 DU patients demonstrated hardly any neutrophil infiltration, despite the increased mucosal IL-8 content in the body. The administration of omeprazole in DU patients markedly increased mucosal neutrophil infiltration even though it did not cause any significant change in the H. pylori density and IL-8 concentration in the body. Although the effect of omeprazole was transient, a significant increase in neutrophil infiltration continued in comparison with the status before omeprazole administration in those subsequently undergoing maintenance treatment with H2-blockers. CONCLUSION: In H. pylori-positive chronic gastritis, IL-8 concentration is enhanced in the mucosa of the body, and is associated with increased neutrophil infiltration. However, in DU patients, despite increases in body IL-8 concentration, neutrophil infiltration is reduced and the gastritis may be localized in the antrum.

Adult↗
PubMed1997

The first exon of the rat aldolase C gene is essential for restoring the chromatin structure in transgenic mice.

A 13-kb fragment of the rat aldolase C gene contains sufficient information for gene expression. Transgenic mice carrying the 13-kb fragment showed restoration of chromatin structure and tissue-specific, copy number-dependent expression. To localize the regulatory elements responsible for restoring chromatin structure, several mutated constructs were used to produce transgenic mice. Three activities were examined: recreation of DNase hypersensitive sites, restoration of methylation status, and copy number-dependent expression. Deletions of the 3'-flanking region did not affect those activities. Deletion of seven introns affected the mRNA levels but not the restoration of the chromatin structure. The insertion of the LacZ gene into the first exon of the transgene interfered with both the restoration of the chromatin structure and the copy number-dependent expression in transgenic mice. DNase I footprinting assays revealed that brain-specific factors bind to the sequence disrupted by the LacZ insertion. These results suggest that the sequence in the first exon is essential for restoring the chromatin structure of the rat aldolase C gene.

Animals↗
PubMed1997

Mouse Mef2b gene: unique member of MEF2 gene family.

The myocyte enhancer factor 2 (MEF2) gene family, which belongs to the MADS [MCM1, agamous, deficiens, serum response factor (SRF)] superfamily, is thought to play an important role in differentiation of myocytes, including cardiomyocytes. To better understand the mouse Mef2 gene family, the mouse Mef2b gene, which was found to be expressed in undifferentiated embryonal cells, was characterized. The Mef2b gene was found to be more than 30 kb in length, consisting of 11 exons. Eight exons correspond to coding regions and the remaining 3 exons for the 5' part are alternatively used. Two internal exons are subject to alternative splicing, resulting in production of four subtypes of mouse MEF2B peptides. Fluorescence in situ hybridization (FISH) and inter-specific backcross analysis identified the Mef2b gene locus. Mef2b gene was expressed in heart or skeletal muscle of early mouse embryo, but not in those of adult mouse. Functionally, mouse MEF2B did not exhibit DNA binding with the MEF2 consensus element in vitro, but did cause transcriptional activation of the MEF2 element, although it was less effective than human MEF2B. Based on these results, mouse MEF2B seems to have a unique character, distinct from other MEF2 family members.

Amino Acid Sequence↗
PubMed1997

Multiregional introgressions inferred from the mitochondrial DNA phylogeny of a hybridizing species complex of gobiid fishes, genus Tridentiger.

Partial sequences of the cytochrome b gene (402 bp) in mtDNA were determined for brackishwater gobiid fishes, genus Tridentiger, collected from geographically distant locations in the Japanese Archipelago, and their interspecific and geographic variations were analyzed and compared. Contrary to the results of a previous allozyme analysis which revealed the existence of considerable genetic divergence (Nei's genetic distance > 0.5) between T. obscurus and T. brevispinis, the mtDNA haplotypes (mitotypes) of these two species were very similar and could not be distinguished by any of the neighbor-joining, maximum-likelihood or parsimony analyses. Hybrid individuals between the two species were also found, with several mitotypes being shared by both species and their hybrids. The phylogenetic relationships of mitotypes were divided into three subgroups, the geographical distributions of the latter being allied to geographical features of the Archipelago. These results suggested the occurrence of multiregional introgression between the two species, with mitotypes transferring from one species to the other.

Animals↗
PubMed1997

Antigenic analysis of human herpesvirus 7 (HHV-7) and HHV-6 using immune sera and monoclonal antibodies against HHV-7.

Using polyclonal and monoclonal (MAbs) antibodies to human herpesvirus 7 (HHV-7), we have studied HHV-7-specific polypeptides. Human sera were obtained during the convalescent phase from patients with exanthem subitum due to HHV-7, and at least 16 HHV-7-specific polypeptides with apparent molecular masses of 26-210 kDa were immuno-precipitated. Sera prepared in mice also precipitated at least 17 HHV-7-specific polypeptides with molecular masses of 26-210 kDa. Among them, the most commonly observed antigenic protein had an apparent molecular mass of 52 kDa. Forty-two clones secreting MAbs against HHV-7-specific proteins, as determined by immunofluorescence assays, were established from BALB/c mice immunized with HHV-7-infected cell extracts. Seven MAbs which immunoprecipitated HHV-7-specific polypeptides were further characterized. Two of these, MAbs 5E12 and 5F12, reacted predominantly with glyco-proteins of 78 kDa and 85 kDa, respectively, and possessed neutralizing activity. This suggests that there are at least two neutralization-inducing proteins in HHV-7. MAb 16B4 reacted with the major immunogenic protein of 52 kDa. Five of the 42 MAbs also reacted in immunofluorescence assays with HHV-6 antigens to the same degree as to HHV-7. Two other MAbs, 7C10 and 10F1, recognized an HHV-7 protein of 40 kDa, and only 7C10 cross-reacted with an HHV-6 protein of 45 kDa.

Animals↗
PubMed1997

Characterization of glycoprotein H and L of human herpesvirus 7.

The genes encoding the glycoproteins H (gH) and L (gL) of human herpesvirus 7 (HHV-7) have been identified. The gH open reading frame (ORF) was 2,070 base pairs in length and encoded a predicted 690 amino-acid protein. The gH contained characteristics of a transmembrane glycoprotein including 10 consensus N-linked glycosylation sites, 12 cysteine residues, a potential amino-terminal signal sequence and a predicted transmembrane segment located near the carboxyl terminus. The gL ORF was 738 base pairs in length and encoded a predicted 246 amino-acid protein. Four possible N-glycosylation sites and 6 cysteine residues existed within gL. The predicted amino-acid sequences of the HHV-7 gH and human herpesvirus 6 variant A (HHV-6A) gH gene products exhibited 23.6% identity to each other; and those of the gL gene products had 26.0% identity. Upon in vitro translation of the gL gene, the addition of microsomal membranes resulted in two modified products with molecular weights of 32 kDa and 35 kDa from the unmodified initial translation product of 26 kDa. An amino-terminal portion of gH and the full length of gL were expressed as glutathione S-transferase fusion proteins, and these proteins were used to raise immune sera in mice. Lysates of cells infected with HHV-7 were subjected to immunoprecipitation analysis. Approximate molecular weights of 33, 37, 80 and 90 kDa polypeptides were immunoprecipitated with antibodies against the gH protein. Antibodies against the gL protein polypeptides with the same molecular weights were also precipitated, and were observed with the antibodies against the gH protein. These results suggest that HHV-7 gH and gL may form a heterodimeric complex with each other in HHV-7 infected cells, as has been reported for other herpesviruses.

Animals↗
PubMed1997

Effect of application volume and area on the absorption of phenol red, as a model drug, from the liver surface in rats.

To determine the influence of the method of administration of a pharmaceutical formulation we have examined the importance of application volume and area in the absorption of phenol red, as a model drug, from the rat-liver surface. When 1 mg phenol red was applied to the rat-liver surface, in-vivo, in three volumes (0.1, 0.2 or 0.334 mL) using a cylindrical glass cell (i.d. 9 mm), the shape of the plasma concentration profile differed greatly, particularly the maximum concentration. These patterns were well fitted by a two-compartment model with first-order absorption, and the absorption-rate constant Ka obtained was inversely proportional to the application volume. The absorption ratio and biliary recovery of phenol red after 6 h increased with glass cell area (i.d. 6, 9 or 14 mm; area 0.28, 0.64 or 1.54 cm2). Furthermore, the permeability coefficient Papp derived from Ka did not depend on application area, indicating no difference in the absorption characteristics of the liver surface. This also implies transport of the drug by passive diffusion from the liver surface. After intraperitoneal administration to the rat-liver surface for clinical application, increasing the application volume resulted in the delayed disappearance of phenol red from the plasma. However, the difference was not as marked as that obtained by use of the glass cell. The assumption that the effective area relating to the absorption changed with the application volume enabled us to estimate Papp. Consequently, we speculate that absorbability can be estimated precisely by consideration of application volume and area.

Adsorption↗
PubMed1997

In-situ ocular absorption of ophthalmic beta-blockers through ocular membranes in albino rabbits.

Ocular membranes have been characterized by in-situ absorption of the ophthalmic beta-blockers carteolol (hydrophilic) and timolol and befunolol (lipophilic) using a cylindrical cell. After introduction of drug solution into the cell on the cornea, sclera (bulbar conjunctival and scleral layer) or palpebral conjunctiva, the disappearance of the drug from the cell was determined as in-situ absorption. The ophthalmic drugs disappeared from the conjunctival and scleral membranes although disappearance from the cornea was hardly observed. The conjunctival membrane showed the highest permeability. Lipophilic drugs were more permeable than hydrophilic. In-situ apparent permeability coefficients of the ophthalmic drugs through the conjunctiva and sclera correlated with the lipophilicity of drugs. A high drug concentration in the aqueous humor was observed after corneal application. There is a relationship between concentration in the aqueous humor was observed after corneal application. There is a relationship between concentrations of drugs in the aqueous humor and previously reported in-vitro apparent permeability coefficients of the drugs in the cornea. This in-situ method using a cylindrical cell is a useful method of investigating the ocular absorption of ophthalmic drugs.

Absorption↗
PubMed1997

Mouse U2af1-rs1 is a neomorphic imprinted gene.

The mouse U2af1-rs1 gene is an endogenous imprinted gene on the proximal region of chromosome 11. This gene is transcribed exclusively from the unmethylated paternal allele, while the methylated maternal allele is silent. An analysis of genome structure of this gene revealed that the whole gene is located in an intron of the Murr1 gene. Although none of the three human U2af1-related genes have been mapped to chromosome 2, the human homolog of Murr1 is assigned to chromosome 2. The mouse Murr1 gene is transcribed biallelically, and therefore it is not imprinted in neonatal mice. Allele-specific methylation is limited to a region around U2af1-rs1 in an intron of Murr1. These results suggest that in chromosomal homology and genomic imprinting, the U2af1-rs1 gene is distinct from the genome region surrounding it. We have proposed the neomorphic origin of the U2af1-rs1 gene by retrotransposition and the particular mechanism of genomic imprinting of ectopic genes.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Effect of Bordetella bronchiseptica and serotype D Pasteurella multocida bacterin-toxoid on the occurrence of atrophic rhinitis after experimental infection with B. bronchiseptica and toxigenic type AP. multocida.

In efficacy tests, 7 primary specific-pathogen-free piglets vaccinated with the Bordetella bronchiseptica and type D Pasteurella multocida bacterin-toxoid were challenged with B. bronchiseptica and type A P. multocida. Severe or moderate nasal turbinate atrophy was produced in the non-vaccinated pigs, whereas, only one of the 4 pigs in the vaccinated group had slight turbinate atrophy. Other immune sera against crude toxin of P. multocida type A or D were cross neutralized. The results of the present study show that the P. multocida serotype D bacterin-toxoid is effective against atrophic rhinitis caused by toxigenic P. multocida serotype A as well as toxigenic P. multocida serotype D.

Animals↗
PubMed1997

[A case report of liaison psychiatry and open heart surgery in a patient with schizophrenia].

The surgical treatment for psychotics remains unsatisfactory because of the potential risk of the sudden death after operation. The perioperative care with an advice from the psychiatrist has been called the liaison psychiatry and considered important to prevent the postoperative psychiatric complication. A 47-year-old male patient who was diagnosed as the schizophrenia underwent aortic valve replacement with an aortic annular enlargement. The cardiac procedure in this patient was accomplished safely without postoperative complications related to the schizophrenia. When the liaison psychiatry is done adequately in the psychiatric patient who needs surgery, an operative procedure can be performed more safely with the minimum risk of the psychiatric complication.

Aortic Valve↗
PubMed1997

[Clinicopathological studies of craniocerebral gunshot injuries].

UNLABELLED: Gunshot wounds are rare in Japan because of few regulatory laws against the possession of guns. Nevertheless such wounds are increasing in prevalence these days. Reports on the microscopic findings concerning these intracerebral lesions are fewer than those on the macroscopic findings in the scalp, the skull and the intracranial cavity. In this study we evaluated computed tomographical and histopathological findings in craniocerebral gunshot injuries. CASES: Nine patients with gunshot wounds to the head were presented. All were male and the age ranged from 17 to 66 years. Four were suicides and four were attempted murders and the last one was of unknown etiology. Morphological examination was performed on 5 autopsy cases. The distance of the bullet from the cranial cavity was as follows: long distance, 4 cases; close contiguity, 5 cases. The calibers of the weapons were as follows: 38 mm in 6 cases, 45 mm in 1 case and unknown in 2 cases. RESULTS: CT scans were examined in six cases, which revealed a missile track, hemorrhagic contusion, traumatic subarachnoid hemorrhage and marked tension pneumocephalus. In some cases, CT scan also revealed bony and metallic fragments, some deep within the cranial cavity. In the histopathological study, we found marked swollen brain (brain weight over 1500 mg) and hemorrhagic contusion in the vicinity of the missile track and interhemispheric fissure, and widespread traumatic subarachnoid hemorrhage and intraventricular hematoma. We would like to emphasize especially the remote contusion seen in the distant part of the missile track as well as massive exsudation and hemorrhage around the nerve fiber bundles. Remote contusion was observed in the inferior surface of the fronto-temporal lobes, and bilateral hemorrhagic contusion was seen in the vicinity of the superior longitudinal fissure on CT scans and autopsy findings. In one case, the bullet rotated within the intracranial cavity. In conclusion, nine cases of craniocerebral gunshot injuries were examined, while we also reviewed the medical literature concerning the shearing injury produced by gunshot brain wounds. The head injuries were further delineated by the correlation between autopsy and computerized tomography findings.

Adolescent↗
PubMed1997

Effect of Helicobacter pylori eradication on subsequent development of cancer after endoscopic resection of early gastric cancer.

Although epidemiological studies strongly suggest an association between gastric cancer and Helicobacter pylori infection, there has been no clinical report indicating that cure of the infection prevents cancer. We conducted a nonrandomized H. pylori eradication trial in patients whose gastric cancer was removed by endoscopic resection (ER). We investigated the effect of treatment on the histopathology of the gastric mucosa, as well as on the incidence of metachronous gastric cancer during the long-term clinical and endoscopic follow-up. One hundred and thirty-two patients with early gastric cancer underwent ER and had H. pylori infection. Sixty-five (group A) were treated with omeprazole and antibiotics to eradicate the infection, and 67 (group B) were not. All patients were followed for 2 years post ER. After eradication treatment in group A, the disappearance of neutrophil infiltration in the antrum and body of the stomach was observed as was a decrease of the severity of intestinal metaplasia. Endoscopy after ER detected no new gastric cancers in these patients. After 3 years of follow-up, 6 (9%) of the 67 patients in group B had a new early-stage, intestinal-type gastric cancer endoscopically diagnosed. The above results suggest that H. pylori eradication may improve neutrophil infiltration and intestinal metaplasia in the gastric mucosa and inhibit the development of new carcinomas. This finding should be confirmed in a randomized, controlled trial.

Adult↗