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T Tanabe

Publications and source records attributed to T Tanabe.

At least 253 records · Page 14Linked to original sources
PubMed1996

Effects of macrophage colony-stimulating factor (M-CSF) on lipopolysaccharide (LPS)-induced mediator production from monocytes in vitro.

M-CSF is a macrophage-lineage-specific growth factor that causes proliferation and differentiation of progenitor cells in the bone marrow. To investigate the effects of M-CSF on more matured cells, human monocytes were cultured in the presence or absence of M-CSF for 6 days. Addition of M-CSF at more than 10(2) U/ml resulted in higher viability and caused morphological differentiation to large macrophage-like cells. LPS-induced mediator production was also compared between M-CSF-treated and control cell. Monocytes were incubated with or without M-CSF for 3 days, and were stimulated with 1 microgram/ml of LPS for 2 days. IL-1 beta was not detected in the both culture supernatants, and PGE2 production was not influenced by M-CSF. However, amounts of G-CSF, GM-CSF, IL-6, and TNF-alpha produced in response to 1 microgram/ml of LPS were 1.5 to 2 times greater from monocytes treated with 10(4) U/ml of M-CSF than from control cells. The priming effect of M-CSF on LPS-induced cytokine production was found to require 3-day preincubation, and reached a maximum at the concentration of 10(4) U/ml. M-CSF-treated cells responded to a 10 times lower concentration of LPS than control cells in terms of cytokine production. M-CSF was also shown by flowcytometric analysis to influence the expression of CD14, a receptor for LPS, which might render monocytes more sensitive to LPS.

Cells, Cultured↗
PubMed1996

Complete endoscopic carpal tunnel release in long-term haemodialysis patients.

The roof of the carpal tunnel (or canal) consists of the distal portion of the flexor retinaculum, the flexor retinaculum (or the transverse carpal ligament) and the proximal portion of the flexor retinaculum. We tried to determine which anatomical structures were relevant to complete endoscopic carpal tunnel decompression in long-term haemodialysis patients with carpal tunnel syndrome. Carpal tunnel pressure was measured using the continuous infusion technique before and after endoscopic release of the flexor retinaculum, distal portion of the flexor retinaculum and the proximal portion of the flexor retinaculum respectively in 257 hands. We concluded that release of the distal portion of the flexor retinaculum, in addition to the flexor retinaculum, is essential for complete carpal tunnel decompression in long-term haemodialysis patients.

Adult↗
PubMed1996

Photoreceptor cell rescue in retinal degeneration (rd) mice by in vivo gene therapy.

Mutations in the beta subunit of the cGMP phosphodiesterase gene (beta PDE) can cause a recessively inherited retinal degeneration in several species, including mice, dogs and humans. We tested the possibility of altering the course of retinal degeneration in the rd mouse through subretinal injection of a recombinant replication-defective adenovirus that contains the murine cDNA for wild-type (beta PDE, Ad.CMV beta PDE. Subretinal injection of Ad.CMV beta PDE results in beta PDE transcripts and increased PDE activity and delays photoreceptor cell death by six weeks. The findings demonstrate cell rescue by in vivo gene transfer, thus supporting the feasibility of treating an inherited retinal degeneration by somatic gene therapy.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

Primary structure of the porcine 89-kDa enamelin.

The primary structure of the 89-kDa enamelin found in porcine secretory enamel at an early stage of development was investigated. The fragments of the enamelin cDNA were amplified by polymerase chain-reaction from the first-strand enamelin cDNA, and were sequenced. The results indicated that the 89-kDa enamelin consisted of 627 amino acid residues and had a molecular mass of 70,448. A hydrophobic domain is located in the region of the 21st-62nd amino acid residues of the molecule. Acidic domains are located in two regions of the molecule-one in the region of the 135th-238th amino acid residues and the other in the C-terminal region. A basic domain is located in the region of the 239th-360th amino acid residues. The results also indicated that the low-molecular-weight enamelins were fragments derived from a prototype enamelin.

Amino Acid Sequence↗
PubMed1996

Possible actions of metalloproteinases found in porcine enamel in an early secretory stage.

In an outermost layer of porcine secretory enamel, metalloproteinases were detected by enzymography with gelatin used as a substrate. When the sample extracted from the outermost layer of the secretory enamel was incubated with calcium ions at 37 degrees C prior to electrophoresis, an increase of the 34-kDa proteinase activity and a decrease of the 76- and/or 78-kDa proteinase activities were observed. The results suggest that the metalloproteinases mediate the conversion from 76- and/or 78-kDa proteinases to the 34-kDa proteinase or the activation of a latent type of the 34-kDa proteinase, and that their activities are regulated by free Ca ions.

Animals↗
PubMed1996

[Scanning electron microscopic study of inner ear barotrauma: in the guinea pig under hypobaric pressure].

In order to investigate the mechanism of inner ear barotrauma, guinea pigs, with bilateral eustachian tube occlusion, were subjected to decompression and compression between 760 and 460 mmHg in a hypobaric pressure chamber. We divided the guinea pigs into two groups, A and B. Group A showed normal eustachian tubes, and group B showed bilaterally occluded eustachian tubes. Group B animals were divided into three types according to the rates of compression and decompression. After pressure loading, morphological changes in the hair cells of the organ of Corti were studied by means of scanning electron microscopy. There was no damage to hair cells in the setting of normal eustachian tube function, as in group A. On the other hand, mild to severe hair cell damage was observed with rapid decompression in group B. This observation suggests that relative positive pressure in the middle ear cavity is an important factor in inner ear barotrauma. The mechanism of hair cell damage due to inner ear barotrauma is presumed to be distortion of the organ of Corti caused by a difference in pressure between perilymph and endolymph resulting in injury to the stereocilica.

Animals↗
PubMed1996

Complete endoscopic carpal canal decompression.

We made a model of the endoscopic decompression of the carpal canal in clinical cases. The model entailed the release of the transverse carpal ligament, ie, the flexor retinaculum, first; then the transverse fibers: deep layer of the midpalmar fascia or distal portion of the flexor retinaculum; and, finally, release of the forearm fascia. Carpal canal pressure was measured using the continuous infusion technique, and the carpal canal was observed endoscopically at each step. Carpal canal pressure data were analyzed by using the Wilcoxon matched pairs signed-rank test. When the transverse carpal ligament and the transverse fibers were divided, carpal canal pressure was significantly statistically lower than that with release of the transverse carpal ligament alone. We conclude that release of both the transverse carpal ligament and the transverse fibers are essential for complete decompression of the carpal canal in endoscopic surgery.

Adult↗
PubMed1996

[Tachyarrhythmias].

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Anti-Arrhythmia Agents↗
PubMed1996

[The effect of preoperative oral fluid intake on the volume and pH of gastric contents in elective surgical patients--a comparison of tea with apple juice].

This study aimed to investigate the effect of 150 ml of either tea or apple juice on the volume and pH of gastric contents in 40 elective surgical patients, ranging in age from 18 to 70 years. They were given diazepam 5 approximately 10 mg and roxatidine 75 mg orally 2 hours before the start of isoflurane anesthesia or modified neuroleptic anesthesia. Immediately following the induction of anesthesia with thiopental and vecuronium, a nasogastric tube was placed to aspirate the gastric content to measure its volume and pH. The volume and pH of gastric contents were 6.4 +/- 8.5 ml, 6.0 +/- 2.2 in tea group and 17.1 +/- 18.4 ml, 4.4 +/- 2.6 in apple juice group, respectively. There was a significant difference in the gastric volume between the two groups (P < 0.05), while no significant difference in gastric pH was observed. This result suggests that apple juice is not appropriate as preoperative drink because apple juice increases gastric contents, and may cause aspiration pneumonia.

Adolescent↗
PubMed1996

[Usefulness of MRA in an infant with cerebral infarction due to streptococcal meningitis].

We described a 4-month-old boy with cerebral infarction due to streptococcal meningitis. He complained of cough and high fever for 2 days. On the next day he admitted to our hospital because of bad humor, drowsiness, and vomiting associated with high fever, respiratory failure and loss of consciousness. On admission, he had opisthotonic posturing, anisocoria and elevated deep tendon reflexes with left side dominance. The cerebrospinal fluid showed increased cells (564/mm3), protein (295 mg/dl), and decreased sugar (1 mg/dl). Streptococcus pneumoniae was detected in the cerebrospinal fluid. Despite intensive treatment by antibiotics, glycerol, and dexamethasone, general condition was worsened, MRI showed a high intense area along the territory of bilateral anterior cerebral arteries and left middle cerebral artery 3-D time-of-flight MRA revealed a decreased signal of these arteries, confirming cerebral infarction. Recanalization of the arteries were observed 17 days after the first MRA examination. Since complication of cerebral infarction influences the prognosis of meningitis, repetitive MRA is very beneficial in patients with bacterial meningitis in order to evaluate the vascular lesion.

Cerebral Infarction↗
PubMed1995

Overexpression of prostacyclin synthase inhibits growth of vascular smooth muscle cells.

To define the local effects of prostacyclin (PGI2) on the growth of vascular smooth muscle cells (VSMC), we transfected VSMC with an expression vector harboring the cDNA for PGI2 synthase (PGIS), which catalyzes the rearrangement of prostaglandin H2 to PGI2. Transfection of the human PGIS cDNA into rat VSMC did not affect DNA synthesis under serum-free basal conditions, but it increased PGI2 synthesis and decreased DNA synthesis under serum-stimulated conditions (in the presence of 1 or 5% fetal calf serum). These results demonstrated that locally synthesized PGI2 can exert autocrine and/or paracrine inhibitory effects on VSMC growth. It was also suggested that in vivo transfer of PGIS gene may be useful for the gene therapy for vascular disease such as neointimal hyperplasia.

Animals↗
PubMed1995

Transcriptional regulation of human prostaglandin-endoperoxide synthase-2 gene by lipopolysaccharide and phorbol ester in vascular endothelial cells. Involvement of both nuclear factor for interleukin-6 expression site and cAMP response element.

There exist two distinct isozymes of prostaglandin-endoperoxide synthase (PES). PES-2 mRNA is synergistically induced by lipopolysaccharide (LPS) and 12-O-tetradecanoylphorbol-13-acetate (TPA) in bovine arterial endothelial cells. On the other hand, PES-1 mRNA is constitutively expressed under these conditions. Therefore, the promoter activities of the human genes for PES-1 and -2 in bovine arterial endothelial cells were examined. The 5'-flanking region of the human PES-2 gene (nucleotides -327 to +59) showed promoter activity inducible by LPS and TPA using transient transfection analysis, whereas that of the PES-1 gene (nucleotides -1010 to +69) showed constitutive promoter activity. Destruction of both consensus sequences for the nuclear factor responsible for the interleukin-6 expression (NF-IL6) site (nucleotides -132 to -124) and the cyclic AMP response element (CRE) (nucleotides -59 to -53) of the human PES-2 gene markedly reduced the promoter activity (25%) of the PES-2 gene after combined treatment with LPS and TPA, although single destruction of the NF-IL6 site or the CRE slightly reduced the promoter activity (60 or 90%, respectively). Moreover, cotransfection experiments showed that a trans-acting factor, CCAAT enhancer binding protein delta (C/EBP delta), which binds to both the NF-IL6 site and the CRE, increased the promoter activity of the PES-2 gene mainly through the CRE. C/EBP delta mRNA was rapidly induced by LPS. Collectively, these results suggest that transcription of the PES-2 gene in vascular endothelial cells is regulated through combination of the NF-IL6 site and the CRE and that C/EBP delta functions as one of the trans-acting factors.

Animals↗
PubMed1995

G-protein modulation of alpha 1A (P/Q) type calcium channel expressed in GH3 cells.

GH3 cell lines stably expressing alpha 1A channel were established and the modulation of this channel by G-protein through membrane-delimited pathways were studied. Wild type GH3 cells were found to express omega-conotoxin MVIIC (MVIIC) sensitive Ca2+ current but this component was different from the alpha 1A channel because of its susceptibility to G-protein modulation, suggesting MVIIC also blocks channels other than P/Q type. Alpha 1A channel expressed in GH3 cells showed slowing of activation and reduction of current amplitude by the application of carbachol. Both of these effects were pertussis toxin (PTX) sensitive and voltage dependent. alpha 1A channels were also found to be modulated through a PTX insensitive pathway, the modulations observed were similar to those in the PTX sensitive pathway. The results further suggest that these two effects are governed by a different mechanism in both PTX sensitive and insensitive pathways.

Animals↗
PubMed1995

Hepatic damage induced by perfusion of radical generating azo compound and its inhibition by vitamin E.

The damaging effect of perfusion of hydrophilic radical generating azo compound on the liver of normal and vitamin E-deficient rats and its inhibition by antioxidants were studied in order to increase understanding of the action of free radicals on biological tissues. The hepatic damage was evaluated from the release of cytosolic enzymes such as glutamic oxaloacetic transaminase and glutamic pyruvic transaminase, mitochondrial oxidation metabolism and morphological change. Two kinds of hydrophilic azo compounds were used, one which decomposes spontaneously at a uniform rate to generate free radicals and the other which does not. The former induced hepatic damage in a dose-dependent manner, while the latter did not exert any damage. Both endogenous vitamin E in the membranes and a water soluble vitamin E analogue added simultaneously with a radical initiator suppressed the hepatic damage. These results show that the hepatic damage induced by perfusion of radical generating azo compound is caused not by the azo compound itself but by free radicals.

Alanine Transaminase↗