Search PubMed⌕ Search

Biomedical subjects

T Endo

Publications and source records attributed to T Endo.

At least 541 records · Page 30Linked to original sources

Pharyngoesophageal reconstruction with a tensor fasciae latae free flap.

This report describes our experience with the use of a tensor fasciae latae flap in total reconstructions of the hypopharynx and cervical esophagus. This flap is durable, reliable, and easy to elevate. Moreover, it is possible to obtain a tight two-layer closure of the circumferential suture lines by means of the vascularized fascia. We think this flap will be one of the methods of choice in reconstructions of the hypopharynx and cervical esophagus.

Carcinoma, Squamous Cell↗

A novel approach to mode of action of cationic biocides: morphological effect on antibacterial activity.

A new concept for the mode of action of cationic biocides is proposed in which the antibacterial activity of cationic disinfectants is ascribed essentially to molecular organizations of cations within aggregates, i.e. the activity is determined by the size of aggregates and number of active molecules comprising the aggregate. On the basis of the new concept, the morphological effect of disinfectants in aqueous solution on the antibacterial activity is discussed for low molecular weight phosphonium salts with single and double long alkyl chains (carbon number 14). The proposed new concept can be applied to all phenomena reported previously in antibacterial activity of cationic biocides and this concept is very important from the viewpoint of molecular design of more active cationic biocides.

Cations↗

Role of an endogenous monoamine oxidase inhibitor, isatin, in SHRSP brain.

1. The acute effects of isatin, an endogenous monoamine oxidase (MAO) inhibitor, on norepinephrine (NE) and serotonin (5-HT) concentrations in the brain of stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY) were determined in order to elucidate its pathophysiological role. 2. Isatin was identified in purified extracts of SHRSP brain. 3. A single dose of isatin significantly increased NE concentration in the cerebral cortex of WKY. Isatin also significantly increased 5-HT concentration in WKY brains. 4. After isatin administration NE and 5-HT levels in the SHRSP brain did not differ from those in WKY. 5. These data suggest that isatin, an endogenous MAO inhibitor, presents in the SHRSP brain and maintains high blood pressure.

Animals↗

Effects of sulfhydryl compounds on the accumulation, removal and cytotoxicity of inorganic mercury by primary cultures of rat renal cortical epithelial cells.

The effects of sulfhydryl compounds on the accumulation, removal and cytotoxicity of inorganic mercury (Hg) were investigated in primary cultures of rat renal cortical epithelial cells. The compounds investigated were 2,3-dimercaptosuccinic acid, 2,3-dimercapto-1-propanol, D-penicillamine, glutathione (GSH) and L-cysteine. In the accumulation experiment, the cells were co-incubated with Hg and the above compounds for 30 min. (short-term) or 18 hr (long-term). In the removal experiment, cells incubated with Hg were further incubated with the above compounds for 30 min. In both experiments, the alleviative effect of the compounds on the cytotoxicity was estimated by the uptake of neutral red or by cell growth. 2,3-Dimercaptosuccinic acid had the highest antidotal effects except for Hg removal. 2,3-Dimercapto-1-propanol exerted the least antidotal effects in the short-term, as well as in the long-term experiments, 2,3-dimercapto-1-propanol increased the Hg accumulation and the cytotoxicity despite its removal of most of the Hg. Although D-penicillamine, L-cysteine and GSH did not increase the Hg removal in the long-term experiment other antidotal effects were seen.

Animals↗

Bacterial activity of a new antiulcer agent, ecabet sodium, against Helicobacter pylori under acidic conditions.

Helicobacter pylori NCTC 11637, which is nonviable at pH 3.0, became viable after addition of 10 mM urea owing to ammonia production by urease. In a buffer supplemented with urea, ecabet sodium decreased both the production of ammonia and the number of viable cells of H. pylori NCTC 11637 and changed the bacteria from the bacilliform to the horseshoe or doughnut shape in a concentration-dependent manner. In particular, ecabet sodium (2 and 4 mg/ml) decreased the number of viable cells below the control level. Benzohydroxamic acid, a urease inhibitor, also caused a decrease in ammonia production accompanied by a decrease in the number of viable cells and changed the morphological form at pH 3.0, but the number of viable cells was not lowered below the control level. In buffers at various pHs without urea, ecabet sodium showed a concentration-dependent bactericidal effect on H. pylori at pHs 4.0 and 5.0 but not at pHs 6.0 and 7.0 while benzohydroxamic acid caused only a slight decrease in the number of viable cells at pH 4.0. These results suggest that ecabet sodium has strong bactericidal activity in addition to its urease-inhibiting activity under acidic conditions.

Abietanes↗

Differential effects of bright light and social cues on reentrainment of human circadian rhythms.

Reentrainment of human circadian rhythm to an 8-h advanced schedule of sleep and social contacts was assessed under two different conditions: with and without bright light (4,000-6,000 lx). Subjects spent 15 days without knowing the natural day-night alternation. On the fourth day, the social schedule was phase-advanced by 8 h. In one experiment, a bright light pulse of 3-h duration was given in every subjective morning, and in the other no light pulse was applied. Plasma melatonin and rectal temperature rhythms were measured. Seven of nine subjects showed an orthodromic phase shift, the rate of which was significantly larger with bright light pulses than without them. The maximum phase-advance shift by three consecutive light pulses was observed when the first pulse was applied approximately 4 h after the onset of melatonin rise. By contrast, the maximum phase shift of a similar extent was detected at 1 h after the onset of melatonin rise, when ordinary room light (300-500 lx) at the time corresponding to bright light was regarded as a dim light pulse. It is concluded that bright light accelerates the reentrainment of human circadian rhythm, and bright light and social schedule have differential effects on the reentrainment.

Adult↗

Identification and localization of immunoglobulin binding factor in bronchoalveolar lavage fluid from healthy smokers.

Immunoglobulin binding factor (IgBF), which is abundant in human seminal plasma, is known to bind immunoglobulin, interact with anti-Fc gamma RIII antibodies, and block pokeweed mitogen (PWM)-stimulated lymphocyte blastogenesis. In this study, we investigated whether IgBF is present in the lower respiratory tract, whose secretions come into contact with the external environment. For this, IgBF was measured in brochoalveolar lavage fluid (BALF) from 42 healthy normal subjects (23 nonsmokers and 19 smokers) by enzyme-linked immunosorbent assay (ELISA). IgBF was detected in BALF from these normal subjects, and its level was significantly higher in BALF from smokers (127.2 +/- 98.7 ng/ml versus 23.3 +/- 20.7 ng/ml). On gel filtration chromatography of BALF, IgBF was eluted in a region corresponding to a molecular weight of 27 kD. Western blot testing with a monoclonal antibody to IgBF indicated that IgBF in BALF had a molecular weight of 27 kD under nonreducing conditions and of 16 kD under reducing conditions. Thus, the migration pattern of IgBF in BALF corresponded to that of IgBF in seminal plasma. IgBF immunoreactivity was detected histochemically in mucus glands and goblet cells in the lower respiratory tract. These results demonstrate that IgBF is present in the lower respiratory tract, and that smoking may cause its increased production in this region.

Adult↗

Induction of cyclooxygenase-2 is responsible for interleukin-1 beta-dependent prostaglandin E2 synthesis by human lung fibroblasts.

Because interleukin-1 beta (IL-1 beta) increases the synthesis of prostaglandin E2 (PGE2) in human lung fibroblasts, the effect of IL-1 beta on the expression of two isozymes of cyclooxygenase (cyclooxygenase-1 and -2) in human embryonic lung fibroblasts (IMR-90) was investigated in terms of three parameters (PGE2 release, cyclooxygenase activity, and mRNA). When the cells were incubated with IL-1 beta, both the PGE2 release to the culture medium and the cyclooxygenase activity in the cell lysate increased in a dose- and time-dependent manner, and both were inhibited by NS-398 (a cyclooxygenase-2-specific inhibitor). Dexamethasone and interleukin-4 (IL-4) inhibited the IL-1 beta-induced PGE2 synthesis; the former inhibited the IL-1 beta-induced cyclooxygenase activity whereas the latter failed. As analyzed by Northern blot, cyclooxygenase-1 mRNAs (3.0 Kb and 5.0 Kb) were detected with resting cells and did not increase by the addition of IL-1 beta. In contrast, the cyclooxygenase-2 mRNA (4.4 Kb) was undetectable with resting cells, but was increased dramatically up to 4 to 8 h by the addition of IL-1 beta. Dexamethasone inhibited the IL-1 beta-induced mRNA expression of cyclooxygenase-2 whereas IL-4 failed. These results indicate that IL-1 beta induces cyclooxygenase-2 rather than cyclooxygenase-1 in IMR-90 cells and this induction is responsible for the augmentation of PGE2 production stimulated with IL-1 beta. However, the inhibition of the IL-1 beta-induced PGE2 synthesis by IL-4 was not mediated by the down-regulation of cyclooxygenase-2.

Base Sequence↗

Adhalin gene mutations in patients with autosomal recessive childhood onset muscular dystrophy with adhalin deficiency.

Homozygous adhalin gene mutations were found in three patients from two consanguineous families with autosomal recessive childhood onset muscular dystrophy. Muscle biopsies from patients in each family showed complete absence of adhalin. Sequencing of adhalin cDNA prepared from skeletal muscle by reverse transcription PCR demonstrated a cytosine to thymidine substitution at nt 229 in the patient in family 1 and an adenine to guanine substitution at nt 410 and a 15-base insertion between nt 408 and 409 in the two patients in family 2. Sequencing of genomic DNA prepared from peripheral blood leukocytes by PCR confirmed these mutations. The parents in each family were found to be heterozygous for the respective mutations. These adhalin gene mutations are presumed to be responsible for the absence of adhalin in the skeletal muscle. Adhalin deficiency likely causes disruption of the muscle cell membrane, resulting in dystrophic changes in the skeletal muscle similar to dystrophin deficiency in Duchenne muscular dystrophy.

Adult↗

A tumor-associated glycosylation change in the glucose transporter GLUT1 controlled by tumor suppressor function in human cell hybrids.

Studies of human cell hybrids have provided evidence that the tumorigenicity of a cervical carcinoma (HeLa) is under the control of a putative tumor suppressor on chromosome 11. Using these human cell hybrids, we found a tumor-associated glycosylation change in the glucose transporter GLUT1, which is an N-linked glycoprotein at the plasma membrane. The non-tumorigenic HeLa x fibroblast cell hybrid CGL1 and the normal diploid fibroblast WI38 expressed the 50-55 kDa GLUT1, whereas in a tumorigenic segregant hybrid, CGL4, as well as in parental HeLa cells, GLUT1 glycosylation was altered and its molecular mass was about 70 kDa. However, the altered GLUT1 glycosylation was not observed in SV40-transformed WI38 cells, suggesting a correlation between this glycosylation change and a putative tumor suppressor function. Further investigations using glycosidases, glycosylation inhibitors and lectin-affinity chromatography demonstrated that the tumor-associated glycosylation change in GLUT1 was mainly due to the increase in N-acetyl-lactosamine repeats in the N-linked oligosaccharides. In accordance with the altered glycosylation, affinity for 2-deoxyglucose in the tumorigenic CGL4 cells increased 2-fold, but there was little change in the Vmax. These results suggest there may be a functional role for the modulation by glycosylation of GLUT1 in the tumorigenic behavior of CGL4 and HeLa cells.

Biological Transport↗

Na(+)- and energy-dependent transport of cadmium into LLC-PK1 cells.

Effects of sodium ions (Na+) and metabolic inhibitors on cadmium (Cd) uptake were investigated in LLC-PK1 cells derived from pig kidney under the nontoxic conditions of Cd. The inoculated cells became confluent on day 7 after the logarithmic growth phase. The initial uptake of Cd (1-60 microM) by the confluent cells (day 7) was assayed. The relationship between the Cd uptake at 37 degrees C and Cd concentration was nonlinear, but the relationship at 4 degrees C was linear. Subtraction of the Cd uptake at 4 degrees C from that at 37 degrees C showed a saturable uptake against the Cd concentration. By the Eadie-Hofstee analysis of saturable uptake, Km and Vmax were 24.6 microM and 164 pmol Cd/mg protein/min, respectively. The uptake of Cd by the cells was significantly decreased by ouabain and the metabolic inhibitors, and by the replacement of Na+ with potassium or choline ion in the incubation medium. These results suggest that Cd is incorporated into the confluent LLC-PK1 cells not only by simple diffusion but also by the carrier-mediated transport involved in Na(+)- and energy-dependent process(es).

2,4-Dinitrophenol↗

A new compound (AZ36041) promotes the survival of the neurons and reduces neurotoxicity of Alzheimer's beta-amyloid protein.

Alzheimer's beta-amyloid protein (A beta) is the main component of senile plaques, which are characteristic hallmarks of the Alzheimer's disease brain. Recently, there have been several reports that A beta has toxic effects on both cultured neurons and in the brain. We confirmed the neurotoxicity of A beta in vitro and found a new compound, called AZ36041 (4-chloro-N-(5-nitro-2-tiazoyl)benzenesulfone amide), which dramatically reduced A beta neurotoxicity. This compound was also found to have a neuroprotective effect against toxicity of glutamate and enhanced neuronal survival in the absence of neurotoxic compounds. AZ36041 may be a useful tool for investigating the mechanism of A beta neurotoxicity in vitro and in vivo.

Amyloid beta-Peptides↗

Inactivation of blasticidin S by Bacillus cereus. V. Purification and characterization of blasticidin S-deaminase mediated by a plasmid from blasticidin S resistant Bacillus cereus K55-S1.

Blasticidin S (BS) deaminase (BSR) from a BS-resistant strain, Bacillus cereus K55-S1, was purified to homogeneity. Molecular weights determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by gel filtration on HPLC are about 15500 and 35000, respectively, indicating the enzyme is a homodimer. The amino acid composition and N-terminal sequence of BSR are the same as those deduced from the nucleotide sequence of the BS-resistant gene, bsr. The optimum temperature and pH for enzyme activity are 60-65 degrees C and near 10.0, respectively. The activity of BSR is inhibited by Cu2+, Hg2+, and p-chloromercuric benzoate (PCMB). Inhibition by PCMB or HgCl2 is reversible by the addition of SH reagents. The enzyme catalyzes the deamination of BS and its derivatives, but not cytosine nucleosides.

Aminohydrolases↗

Molecular cloning and sequence analysis of a gene encoding an extracellular serine protease from Streptomyces lividans 66.

A gene encoding a homolog of the chymotrypsin-like serine protease (SAM-P20), which was isolated as the target enzyme of a protease inhibitor (SSI), was cloned from Streptomyces lividans 66. This gene contained an open reading frame of 1065 nucleotides encoding 354 amino acid residues with a putative prepro portion of 157 amino acid residues. The deduced amino acid sequence of the cloned gene had significant homology to those of members of Streptomyces extracellular chymotrypsin-like protease family. By Southern blot analysis, it was suggested that protease genes of this type are found at a high frequency in Streptomyces. In this sense, we propose to categorize this protease as a member of the 'SAL' series (SAM-P20-like proteases).

Amino Acid Sequence↗

Metal transport in cells: cadmium uptake by rat hepatocytes and renal cortical epithelial cells.

The toxic metals appear to use the transport pathways that exist for biologically essential metals. In this regard interactions between the toxic and essential metals are possible. This report summarizes recent findings on the transport of cadmium in rat hepatocytes and renal cortical epithelial cells in the presence or absence of certain essential metals. The transport of cadmium in hepatocytes does not require energy and, therefore, is not an active process. It occurs primarily (80%) by temperature-sensitive processes, i.e., ion channels and carriers, that involve interaction with sulfhydryl groups. These processes apparently exist for the transport of essential metals like copper, zinc and calcium. The remaining 20% of the cadmium in hepatocytes is transported via a temperature-insensitive process, possibly by diffusion. In comparison with the hepatocytes, a smaller fraction (30%) of the cadmium transport through the basolateral membrane and none from the apical membrane of the renal cortical epithelial cells is temperature-sensitive. Total accumulation through the basolateral membrane is about twice that through the apical membrane. A majority of the cadmium transport in the renal cells is by diffusion. As in hepatocytes, copper, zinc and mercury antagonize cadmium transport through the apical membranes of the renal cells. The relative antagonism by copper is the same (25%); however, the antagonism by zinc (16%) and mercury (10%) is 4- to 6-fold lower than in hepatocytes. It appears that the relative contribution of various transport pathways available for cadmium uptake is different in each cell type and apparently depends on the morphological and functional differences between the cell membranes.

Animals↗

Central GABAergic mechanisms are defective in salt-induced hypertension in borderline hypertensive rats.

We examined the role of central GABAergic mechanisms in salt-induced hypertension and exaggerated responses to stress in borderline hypertensive rats (BHR), the first offspring of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The studies were done in conscious BHR and WKY on high (H) (8% NaCl) or normal (N) (0.3% NaCl) salt diets for 5 weeks. A high-salt diet elevated arterial pressure (AP) (p < 0.01) and augmented pressor responses to shaker stress (p < 0.05) in BHR but not in WKY. Intravenous hexamethonium caused a greater decrease in AP in BHR-H than in BHR-N at rest. Muscimol (a GABA agonist) injected into the central ventricle (i.c.v.) caused a greater decrease in resting AP (p < 0.01) and heart rate (HR) (p < 0.05) and BHR-H than in BHR-N. Renal sympathetic nerve activity (RSNA) did not change in BHR-H, but increased (p < 0.05) in BHR-N during muscimol-induced hypotension, although the magnitudes of muscimol-induced hypotension were greater in BHR-N than in BHR-N. The increases in RSNA in response to intravenous nitroglycerin were similar in BHR-N and BHR-N. Muscimol attenuated pressor and tachycardic responses to stress more in BHR-N than in BHR-N (p < 0.01). Muscimol did not alter AP and HR at rest or their responses to stress in the two groups of WKY. The magnitudes of pressor response to bicuculline (a GABA antagonist) did not differ between the two groups of BHR. These results suggest that a high salt diet may alter the central GABAergic system in BHR, which contributes to salt-induced hypertension and augmented pressor and tachycardic responses to stress.

Animals↗

Effects of splenectomy on luteolysis in pseudopregnant rabbits.

The effects of splenectomy on luteolysis in pseudopregnant rabbits were observed. Pseudopregnancy was induced in the rabbits by mating with vasoligated mature males and injection of human chorionic gonadotrophin (D0). In these rabbits, the concentration of serum progesterone increased for 7 days after the induction of pseudopregnancy. In the control group (sham-operation), the concentration of serum progesterone returned to the level of the pre-ovulatory levels by 14 days of pseudopregnancy. On the other hand, in the splenectomized group, in which splenectomy was performed at D7, the serum progesterone concentration was maintained at the level of the functional luteal phase (D7) at least until 21 days of pseudopregnancy. These findings indicate that the spleen is concerned with luteolysis of the rabbit.

Animals↗