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Biomedical subjects

T Doi

Publications and source records attributed to T Doi.

At least 37 records · Page 2Linked to original sources
PubMed1996

Bell palsy and herpes simplex virus: identification of viral DNA in endoneurial fluid and muscle.

OBJECTIVE: To determine whether herpes simplex virus type 1 (HSV-1) causes Bell palsy. DESIGN: Prospective study. SETTING: University inpatient service. PATIENTS: 14 patients with Bell palsy, 9 patients with the Ramsay-Hunt syndrome, and 12 other controls. MEASUREMENTS: Viral genomes of HSV-1, varicella-zoster virus, and Epstein-Barr virus were analyzed in clinical samples of facial nerve endoneurial fluid and posterior auricular muscle using polymerase chain reaction (PCR) followed by hybridization with Southern blot analysis. RESULTS: Herpes simplex virus type 1 genomes were detected in 11 of 14 patients (79%) with Bell palsy but not in patients with the Ramsay-Hunt syndrome or in other controls. The nucleotide sequences of the PCR fragments were identical to those of the HSV-1 genome. CONCLUSIONS: Herpes simplex virus type 1 is the major etiologic agent in Bell palsy.

Adult↗
PubMed1996

Differentiation of smooth muscle phenotypes in mouse mesangial cells.

Smooth muscle alpha-actin (SMA) mRNA, a marker of vascular smooth muscle cells, was identified in the normal glomerular mesangium both in vivo and in vitro. Several populations of mesangial cells were studied to determine if SMA and basement membrane collagen were regulated together. The levels of SMA expression, which could be linked to the stage of differentiation, were different for the differing cell populations. One cell population had high SMA and type IV collagen levels at its early passages. The others expressed both interstitial and basement membrane collagens. The first population developed these phenotypic features at later passages. The levels of SMA and alpha 1(IV) collagen expression were regulated together in concert, whereas the alpha 2(I) collagen levels were expressed inversely to SMA and alpha 1(IV) collagen. Both SMA and type IV collagen were controlled by the methylation states of the cis-regulators; however, type I collagen was mainly regulated by the trans-acting regulators. Treatment with 5-azacytidine converted the cells of a fibroblast-phenotype to a smooth muscle cell-like phenotype. These cell lines may be useful for studying the differentiation process in vitro.

Actins↗
PubMed1996

Advanced glycation end products modulate transcriptional regulation in mesangial cells.

Advanced glycation end products (AGEs) stimulate synthesis of extracellular matrix (ECM) in a receptor-mediated manner on mesangial cells. In the present study, we examined the transcriptional regulation of the gene for type IV collagen [(IV)collagen], which is one of the major components of mesangial sclerosis, after stimulation of AGEs on mesangial cells. The methylation pattern of the promoter/enhancer region of (IV)collagen gene was similar in AGE-treated and control cells. AGEs significantly increased the transcriptional activity of the (IV)collagen gene, as measured by transient transfection assays using the reporter gene construct containing (IV)collagen promoter/enhancer and the chloramphenicol acetyltransferase gene. AGEs also increased smooth muscle alpha-actin mRNA levels as well as its transcriptional activity. Nuclear factor binding of the promoter of (IV)collagen gene was stimulated by AGEs. Furthermore, AGEs dramatically decreased the mRNA levels of (IV)collagen promoter binding protein (MSW), a larger subunit of DNA replication complex, AP1. These results suggest that AGEs increase expression of (IV)collagen gene by modulating the levels of promoter binding proteins. These transcriptional events may play a critical role in ECM accumulation in response to AGEs.

Actins↗
PubMed1996

Synthetic collagen-like domain derived from the macrophage scavenger receptor binds acetylated low-density lipoprotein in vitro.

The bovine macrophage scavenger receptor is a 70 kDa membrane protein that is trimerized on the macrophage cell surface. The receptor binds modified low-density lipoproteins (LDL). The core binding site is located within 22 residues at the C-terminus of the collagen-like domain of the receptor. The Lys residue at position 337 plays an important role in ligand binding. Here, the collagen-like domain was constructed using a peptide architecture technique, in which three collagenous peptide chains were crosslinked at their N-termini. The crosslinked peptide showed a collagen-like structure by circular dichroism and existed mainly in a monomeric triple helical form as shown by gel exclusion chromatography. The triple-stranded peptide was demonstrated to bind acetylated LDL (Ac-LDL) using regions derived from Gly323 to Lys340 of the natural bovine scavenger receptor. However, a single-stranded peptide with the same amino acid sequence did not bind Ac-LDL. Furthermore, a triple-stranded mutated peptide in which Lys corresponding to Lys337 in the mother protein was substituted with Ala showed no binding activity to Ac-LDL. These results, taken together, indicate that the synthetic collagen-like peptide has a similar structure to the binding site in the scavenger receptor, and support the view that the collagen-like domain of the natural scavenger receptor recognizes Ac-LDL.

Amino Acid Sequence↗
PubMed1996

Collagenous macrophage scavenger receptors.

Collagen, the most abundant protein in the human body, is a major constituent of extracellular matrix. Among macrophage membrane proteins, type I and II scavenger receptors and MARCO contain a collagenous domain. Analysis of type I and II receptor knockout mice and histochemical studies indicate that these proteins play roles in scavenger, adhesion and host defense functions of macrophages.

Animals↗
PubMed1996

[MRSA enteritis following severe gastroenteritis of salmonellosis].

A 62-year-old female patient was given cancer chemotherapy for lymph nodes metastases in the left breast cancer. She was admitted to the hospital because of severe watery diarrhea, in hypovolemic shock, and was diagnosed as suffering from not-typhoidal Salmonella by stool culture. After systemic administration of antibiotic agents, she became well in a few days, but on the 16th hospital day, she had severe watery diarrhea, hypovolemic shock and then cardiac arrest. She was resuscitated immediately. The stool culture revealed methicillin-resistant Staphylococcus aureus (MRSA), type II coagulase, producing TSST-1 and type BC staphylococcal enterotoxin. It was thought that in this case, MRSA enteritis was caused by damage of the intestinal mucosal barrier of the defense mechanism against infection due to salmonellosis and administration of multiple antibiotic agents.

Anti-Bacterial Agents↗
PubMed1996

Multiple function of macrophage scavenger receptors mediated by fibrous coiled coil domains.

Type I and type II macrophage scavenger receptors (MSR) have six structurally distinct domains. MSR are known to mediate a wide range of ligand recognition, endocytosis, phagocytosis and macrophage adhesion. Expression of mutated receptors in various cultured cells and analysis using synthetic peptides indicate that two coiled-coil domains, alpha-helical coiled-coil domain (domain IV) and collagen-like domain (domain V) mediate these functions. Domain IV is essential for the trimerization of MSR and EDTA-resistant adhesion function. Domain V is essential for the wide range of ligand recognition. Cooperation of these two domains is also essential for the cellular function of MSR including pH-dependent ligand dissociation.

Amino Acid Sequence↗
PubMed1996

Role of herpes simplex virus infection in the pathogenesis of facial paralysis in mice.

To clarify the role and site of herpes simplex virus (HSV) infection in the pathogenesis of facial paralysis, we examined the viral genome by the polymerase chain reaction and the neutralization antibody titer using microplates in an animal model. Following inoculation with HSV type 1 of the KOS strain into mouse auricles, HSV DNA appeared in the ipsilateral facial nerve on the 3rd day, and in bilateral facial nerves and the brain stem on the 10th day only in animals with facial paralysis. In animals without facial paralysis, no HSV DNA was detected in these tissues. The neutralization antibody titer was elevated between 4 and 20 days in all animals, with or without facial paralysis. Facial paralysis developed only on the inoculated side, even though HSV DNA was also present in the contralateral facial nerve. We conclude that HSV infection in the facial nerve and brain stem is prerequisite for facial paralysis, and suggest that an immunologic reaction following viral infection plays a key role in the pathogenesis.

Animals↗
PubMed1996

In vivo biological activity of antioxidative aminothiazole derivatives.

For the development of novel antioxidants having therapeutic utility, a new series of condensed 4- and 5-aminothiazole derivatives has been synthesized using simple methods. Condensed 4-aminothiazoles were prepared by the reaction of alpha-bromolactams with thioamides in ethanol and 5-aminothiazole derivatives were obtained by the treatment of 3-(acylamino)lactams with a thiating agent such as phosphorous pentasulfide and Lawesson's reagent in pyridine. In vitro assay of the condensed 5-aminothiazole derivatives showed them to be potent inhibitors of lipid peroxidation. In order to evaluate these compounds in an in vivo system, we devised a simple and reproducible method in which the inhibition of characteristic behaviors induced by spinal injection of FeCl2 was expressed numerically. Compounds having strong in vitro activity protected the central nervous system form injury caused by iron-dependent lipid peroxidation. The results suggest that the in vivo assay developed in this study should be useful as a screening method for antioxidants and also that condensed 5-aminothiazole derivatives are promising candidates for the treatment of traumatic and ischemic injury of the central nervous system.

Animals↗
PubMed1996

[Demonstration and characterization of CD 46, membrane cofactor protein, in gastric cancer tissue].

CD 46, membrane cofactor protein, is a membrane protein which shows different expression and phenotypes with the organ or cell in the same individual. Previously, we reported that gastric CD 46 was expressed strongly in the mucosal epithelium, mucosa and endothelial cells of vessels in the submucosal layer. Western blot analysis revealed that gastric CD 46 was expressed as one broad band with a molecular weight ranging from 60 kDa to 69 kDa, which was different from that of lymphocytes. In this study, we investigated the differences in expression and characterization of CD 46 in gastric cancer obtained by surgery as compared with non-cancerous mucosa. Expression of CD 46 was greater in gastric cancer than in non-cancerous mucosa. In some cases, the phenotypes of CD 46 in gastric cancer were different from those in the non-cancerous tissue.

Aged↗
PubMed1996

[Expression and characterization of CD46, membrane cofactor protein, in human colonic mucosa].

CD 46, membrane cofactor protein (MCP), is a membrane regulatory glycoprotein of the complement system, and acts as a cofactor of factor I, which inactivates C3b and C4b bound on autologous cell membrane. MCP is present on human peripheral blood cells except erythrocytes, fibroblasts, epithelial and endothelial cells, and has been proved to exist in other organs including gastrointestinal tract recently. In this study the expression and characterization of MCP on normal human colonic mucosa was investigated. Immunohistochemical study showed MCP in the colonic mucosal epithelium. Western blot analysis revealed that MCP protein was expressed as a broad band of 50-65 kDa in all cases and another faint band of 43-46 kDa in 3 out of 20 cases, though the latter band was highly suspected to be originated from contaminated mononuclear cells in the colon.

Antigens, CD↗
PubMed1996

[Demonstration and characterization of CD46, membrane cofactor protein in the stomach].

CD46, membrane cofactor protein, is a glycoprotein widely present on the cell membranes and is different in molecular weight among organs or cells in the same individual. It acts as a cofactor of I of the complement system, which inactivates C3b bound to the autologous cells, and protects them from the attack of the complement. In this study CD46 was demonstrated in the stomach immunochemically. Gastric CD46 was expressed strongly in the mucosal epithelium, mucosa and endothelial cells of the vessels in the submucosal layer, whereas expressed weakly in the submucosa and muscle. Western blot analyses revealed that gastric CD46 was expressed as one broad band with molecular weight ranging from 60 kDa to 69 kDa, which was distinct from that of lymphocytes in the peripheral blood.

Aged↗
PubMed1996

Direct measurement of eustachian tube compliance.

We developed a method by which tubal compliance can be directly measured, and using this method we examined tubal compliance in 18 adults with a disease-free ear and 8 adults with chronic otitis media. This method is advantageous in that one can directly measure tubal compliance in the cartilaginous part of the eustachian tube. It is our view that each eustachian tube has its own compliance which is not influenced by mucosal swelling or muscle tension around the tube.

Adult↗
PubMed1996

Primary intramedullary spinal cord germinoma. Case report.

Primary central nervous system germinoma usually presents as an extraaxial intracerebral mass. The authors report the rare occurrence of an intramedullary spinal cord germinoma at the conus medullaris in a 24-year-old man, which was treated by partial removal and radiation therapy. The tumor was highly radiosensitive and the patient remains disease free 15 months posttreatment.

Adult↗
PubMed1996

[Surgery for thoracic aortic aneurysm in the elderly patients with renal insufficiency and pulmonary disfunction].

Renal insufficiency and pulmonary disfunction are the major risk factors of surgical treatment for thoracic aortic aneurysm (TAA). The 1st case was 79-year-old female with ruptured TAA. The 2nd case was 76-year-old female with thoraco-abdominal aortic aneurysm. Both patients successfully treated with graft replacement using temporally shunt (12 mm Gore-Tex graft), tracheostomy and epidural analgesia.

Aged↗
PubMed1996

[Isoflurane and sevoflurane impair left ventricular relaxation in dogs with fixed heart rate].

The effects of isoflurane (Iso) and sevoflurane (Sev) on left ventricular relaxation were evaluated in 22 open-chest dogs with fixed heart rate (130 beats.min-1) using atrial pacing. Fentanyl was injected intravenously to maintain anesthesia during the preliminary preparation. In both Iso and Sev groups (n = 11), left ventricular systolic pressure, mean aortic pressure and dp/dt max were significantly decreased at 0.5 MAC, but there was no significant change in left ventricular end-diastolic pressure. Left ventricular systolic function was depressed to the similar extent in both groups. In Sev group, -dp/dt max and time constant of isovolumic left ventricular pressure fall (T) increased significantly at 0.5 MAC but it increased at 1.5 MAC in Iso group. T at 0.5 MAC Sev was also significantly longer compared with T at equipotent Iso. These findings suggest that Sev may impair isovolumic left ventricular relaxation more strongly than Iso, and this may result from the difference of the effect of each agent on intracellular Ca2+ homeostasis in the myocardium.

Anesthetics, Inhalation↗