Biomedical subjects

T Endo

Publications and source records attributed to T Endo.

At least 37 records · Page 2Linked to original sources

PubMed2002

Intracranial cerebrospinal fluid measurement studies in suspected idiopathic normal pressure hydrocephalus, secondary normal pressure hydrocephalus, and brain atrophy.

OBJECTIVE: To investigate intracranial cerebrospinal fluid (CSF) distribution in patients with a clinical diagnosis of idiopathic normal pressure hydrocephalus (INPH). METHODS: 24 patients with a clinical diagnosis of INPH were studied. Control groups comprised 17 patients with secondary normal pressure hydrocephalus (SNPH), 21 patients with brain atrophy, and 18 healthy volunteers. Ventricular volume (VV) and intracranial CSF volume (ICV) were measured using a magnetic resonance based method and the VV/ICV ratio was calculated. RESULTS: The SNPH group showed a marked increase in the VV/ICV ratio compared with the healthy volunteers (37.8% v 15.6%, p < 0.0001). The brain atrophy group showed a significant increase in ICV compared with the healthy volunteers (284.4 ml v 194.7 ml, p =0.0002). The INPH group showed an increase in ICV (281.2 ml, p = 0.0002) and an increase in the VV/ICV ratio (38.0%, p < 0.0001). Fifteen of 24 INPH patients underwent shunting; 11 improved and four did not. CONCLUSIONS: The results suggest that INPH patients have brain atrophy in addition to hydrocephalic features. This may help to explain the difficulties encountered in the diagnosis and the unpredictable response rate to shunt surgery in INPH patients.

Aged↗

PubMed2001

Noradrenaline stimulates 5-hydroxytryptamine release from mouse ileal tissues via alpha(2)-adrenoceptors.

The effect of noradrenaline on 5-hydroxytryptamine (5-HT) release from isolated mouse ileal tissues was investigated. Noradrenaline, but not isoprenaline, at 1 microM stimulated 5-HT release, an effect which was inhibited by yohimbine, an alpha(2)-adrenoceptor antagonist, but not by bunazosin, an alpha(1)-adrenoceptor antagonist. alpha(2)-Adrenoceptor agonists, UK 14,304 (5-bromo-6-(2-imidazolin-2-yl-amino)-quinoxaline) and clonidine at a higher concentration (10 microM) also stimulated 5-HT release, while alpha(1)-adrenoceptor agonists, methoxamine and phenylephrine, had no effect. The effect of noradrenaline was completely abolished in ileal tissues isolated from mouse treated with pertussis toxin (100 microg/kg, i.v.) for 2 days. These results suggest that noradrenaline causes 5-HT release from enterochromaffin cells in mouse ileal tissues via alpha(2)-adrenoceptor subtypes coupled to a pertussis toxin-sensitive G protein.

Adrenergic alpha-2 Receptor Agonists↗

PubMed2001

Induction of inflammatory response of mice exposed to diesel exhaust is modulated by CD4(+) and CD8(+) T cells.

Exposure to diesel exhaust (DE) increased airway inflammatory responses and airway responsiveness to allergen challenge. To clarify the roles of T cells in DE exposure-induced early inflammation, we studied the effect of CD4 and CD8 cells on the effect DE might have on allergic inflammation by using monoclonal antibody-mediated cellular depletion assays. In the bronchoalveolar lavage (BAL) fluid, the numbers of inflammatory cells from 3 mg/m(3) DE-exposed and ovalbumin (OVA)-immunized mice markedly increased. Depletion of CD4(+) cells resulted in reduced accumulation of inflammatory cells. DE exposure to OVA-immunized mice significantly increased interleukin (IL)-1 beta production but decreased IL-12 production. DE exposure significantly enhanced production of the macrophage inflammatory proteins (MIP)-1 alpha and MIP-2, but not monocyte chemoattractant protein (MCP)-1 and regulated upon activation normal T cells expressed and secreted (RANTES). Treatment with anti-CD4 and anti-CD8 mAbs abrogated the adverse effect of DE exposure. In CLN cells from OVA + DE-exposed mice, CD45R/B220-, CD3-, CD4-, and CD8-positive cells were significantly increased, but the OVA-stimulated cytokine production remained at the same levels with OVA-immunized mice. These findings suggest that the induction of early inflammatory responses by DE exposure may initially be related to the modulated function of lymphocyte subpopulations.

Animals↗

PubMed2001

Effects of CP-99, 994, a tachykinin NK(1) receptor antagonist, on abdominal afferent vagal activity in ferrets: evidence for involvement of NK(1) and 5-HT(3) receptors.

The effect of CP-99, 994, a tachykinin NK(1) receptor antagonist, on abdominal vagal afferent nerve activity in the ferret was investigated. Substance P (1 microg/kg, i.v.) increased vagal afferent activity by 449.0+/-51.9% and this was reduced to 145.9+/-5.7% (p<0.01) by pre-treatment with CP-99, 994 (1 mg/kg, i.v.), and to 149.5+/-1.5% (p<0.001) by granisetron (1 mg/kg, i.v.), a 5-HT(3) receptor antagonist. In addition, the increase in vagal nerve activity induced by 5-HT (25 microg/kg, i.v., 552.0+/-57.0% increase from pre-injection level) was significantly reduced (401.3+/-10.6% increase from pre-injection level, p<0.05) by CP-99, 994 (100 microg/kg, i.v.). These results provide evidence for an involvement of peripheral NK(1) and 5-HT(3) receptors in substance P-induced vagal afferent activation. While the functional consequences (if any) of such peripheral effects were not investigated, they could contribute either directly (e.g. by blockade of receptors on vagal afferents) or indirectly (e.g. modulation of 5-HT release or reduction of local inflammatory response) to the antiemetic effects of CP-99, 994 against cisplatin and other emetic agents acting primarily via the vagus.

Abdomen↗

PubMed2001

Inhibition by docosahexaenoic acid of receptor-mediated Ca(2+) influx in rat vascular smooth muscle cells stimulated with 5-hydroxytryptamine.

The effect of docosahexaenoic acid treatment on intracellular Ca(2+) dynamics in rat vascular smooth muscle cells stimulated with 5-hydroxytryptamine (5-HT) has been investigated in order to elucidate one of the mechanisms for its beneficial effect on cardiovascular disorders. The treatment of cells with 30 microM docosahexaenoic acid for 2 days inhibited an increase in intracellular Ca(2+) concentration induced by 5-HT (10 microM) and a depolarizing concentration of KCl (80 mM). Docosahexaenoic acid treatment significantly inhibited divalent cation influx stimulated by 5-HT and KCl, as measured by Mn(2+) quenching method, whereas had no effect on 5-HT-induced Ca(2+) release from the internal stores. Docosahexaenoic acid treatment also significantly inhibited 5-HT receptor-mediated Ca(2+) influx through Ni(2+)-insensitive channels that were distinct from store-operated channels. These results suggest that the specific inhibition of intracellular Ca(2+) dynamics in vascular smooth muscle cells may contribute to the beneficial properties of docosahexaenoic acid on cardiovascular disorders.

Animals↗

PubMed2001

Clinicopathologic and prognostic significance of matrilysin expression at the invasive front in human colorectal cancers.

Matrix metalloproteinases (MMPs) have been implicated in tumor progression. Matrilysin, one of the matrix metalloproteinases, is frequently overexpressed in gastrointestinal cancers. The aim of our study was to assess the validity of matrilysin as a prognostic marker of colorectal cancers. Matrilysin expression was immunohistochemically analyzed using formalin-fixed, paraffin-embedded specimens from 113 colorectal cancer patients who had undergone curative surgery. The lumenal surface of neoplastic glands in the superficial layer was apically stained, while the cytoplasm of cancer cells at the invasive front was diffusely stained for matrilysin. Sections with immunostaining signals in more than 30% of carcinoma cells at the invasive front, which were observed in 47 (42%) cases, were judged as being positive for matrilysin. Matrilysin positivity was significantly correlated with the depth of invasion, lymph node metastasis, lymphatic invasion, advanced Dukes' stage and poor outcome. Patients with matrilysin-positive cancer had a significantly shorter overall survival time than those with matrilysin-negative cancer. For patients with intermediate invasive tumor (T2 or T3), only matrilysin was a significant prognostic variable for predicting overall survival in multivariate analysis. Matrilysin expression at the invasive front could be an important marker, predicting an unfavorable prognosis after surgical treatment in patients with colorectal cancer.

Biomarkers, Tumor↗

PubMed2001

Molecular chaperones in the yeast endoplasmic reticulum maintain the solubility of proteins for retrotranslocation and degradation.

Endoplasmic reticulum (ER)-associated degradation (ERAD) is the process by which aberrant proteins in the ER lumen are exported back to the cytosol and degraded by the proteasome. Although ER molecular chaperones are required for ERAD, their specific role(s) in this process have been ill defined. To understand how one group of interacting lumenal chaperones facilitates ERAD, the fates of pro-alpha-factor and a mutant form of carboxypeptidase Y were examined both in vivo and in vitro. We found that these ERAD substrates are stabilized and aggregate in the ER at elevated temperatures when BiP, the lumenal Hsp70 molecular chaperone, is mutated, or when the genes encoding the J domain-containing proteins Jem1p and Scj1p are deleted. In contrast, deletion of JEM1 and SCJ1 had little effect on the ERAD of a membrane protein. These results suggest that one role of the BiP, Jem1p, and Scj1p chaperones is to maintain lumenal ERAD substrates in a retrotranslocation-competent state.

Carboxypeptidases↗

PubMed2001

[Epidemiology and laboratory diagnostics of legionellae].

The severe pulmonary disease caused by the inhalation of the different Legionella species is called Legionella pneumonia, while the name of the pulmonary disease caused by the most common Legionella (L. pneumophila) is Legionnaires' disease. Another type of disease caused by legionellae is Pontiac fever with influenza-like symptoms. Legionella spp. are facultative intracellular parasites. They survive within both monocytes in the human organism and amebae in the environment. To prevent and control the occurrence of legionelloses, legionellae should be surveyed and detected in the environmental (water pipes, air-conditioning systems, cooling towers, respiratory equipments, etc.) and clinical (blood, bronchoalveolar lavage, sputum, abscess, etc.) samples. Laboratory diagnosis is complicated by the limitations of the available assays. Thus, it is proposed that the microbiological laboratory diagnosis should be based on the simultaneous application of at least three methods (culturing [on BCYE medium], followed by biochemical assays, serology, molecular biologic methods, such as polymerase chain reaction [PCR], direct demonstration [immunofluorescence microscopy], antigen determination are the most important ones) and on the simultaneous demonstration from three different samples (e.g. lower respiratory tract secretions, sputum, urine, blood culture, serum, moreover, water samples from all potential infectious sources, sediment of hot water tanks, as well as swab samples of faucets and shower heads). The advantage of PCR is that is gives reliable results in one day, in contrast to conventional culturing. However, its sensitivity can not be improved by increasing the sample volume, and neither can it give quantitative results nor can it produce strains for epidemiologic studies, contrary to the method of culturing. It is concluded that PCR and culturing do complement, but do not substitute each other.

Antigens, Bacterial↗

PubMed2001

Analysis of N-glycans of pathological tau: possible occurrence of aberrant processing of tau in Alzheimer's disease.

In a previous study [Wang et al. (1996) Nat. Med. 2, 871-875], Wang et al. found (i) that abnormally hyperphosphorylated tau (AD P-tau) isolated from Alzheimer's disease (AD) brain as paired helical filaments (PHF)-tau and as cytosolic AD P-tau but not tau from normal brain were stained by lectins, and (ii) that on in vitro deglycosylation the PHF untwisted into sheets of thin straight filaments, suggesting that tau only in AD brains is glycosylated. To elucidate the primary structure of N-glycans, we comparatively analyzed the N-glycan structures obtained from PHF-tau and AD P-tau. More than half of N-glycans found in PHF-tau and AD P-tau were different. High mannose-type sugar chains and truncated N-glycans were found in both taus in addition to a small amount of sialylated bi- and triantennary sugar chains. More truncated glycans were richer in PHF-tau than AD P-tau. This enrichment of more truncated glycans in PHF might be involved in promoting the assembly and or stabilizing the pathological fibrils in AD.

Alzheimer Disease↗

PubMed2001

Transcriptional activation of the thyroglobulin promoter directing suicide gene expression by thyroid transcription factor-1 in thyroid cancer cells.

Gene therapy with thyroglobulin (TG) promoter and a prodrug/suicide gene combination may prove useful as a treatment for thyroid carcinoma. However, most poorly differentiated and anaplastic thyroid carcinomas have lost the ability to express the TG gene expression accompanied by loss of transcription factors [thyroid transcription factor-1 (TTF-1), TTF-2, or Pax-8] interacting with the TG promoter. In anticipation of developing transcriptionally targeted gene therapy of TG-nonproducing thyroid carcinomas, we investigated the effect of TTF-1 gene transfer on TG promoter activity and the cytotoxic effect obtained by the TG promoter-driven HSV-TK gene along with ganciclovir in thyroid carcinoma and nonthyroidal cells. Using a chimeric construct containing the 5'-flanking region of the rat TG gene between -826 and +39 bp and the luciferase gene, TG promoter activity was detected in a normal rat thyroid cell line (FRTL-5), but not in a dedifferentiated line of thyroid cells (FRT) expressing Pax-8 but not TTF-1, TTF-2, or TG [TTF-1(-)/TTF-2(-)/Pax-8(+)/TG(-)], or in a human papillary thyroid carcinoma cell line [BHP15-3; TTF-1(-)/TTF-2(-)/Pax-8(-)/TG(-)], a human pulmonary cell line [H441; TTF-1(+)/TTF-2(-)/Pax-8(-)/TG(-)], or a dog kidney epithelial cell line [MDCK; TTF-1(-)/TTF-2(-)/Pax-8(+)/TG(-)]. Cotransfection of the TTF-1 expression vector stimulated TG promoter activity in FRT and BHP15-3 dedifferentiated thyroid cells, but not in H441 pulmonary cells. Only weak activation was observed in MDCK kidney cells. We then constructed recombinant adenovirus vectors, AdTTF-1 and ADTGTK: AdTTF-1 contained cytomegalovirus promoter and rat TTF-1 cDNA; AdTGTK carried the TG promoter-driven HSV-TK gene. Infection with AdTGTK and combined with GCV treatment induced a cytotoxic effect in FRTL-5 cells but not in dedifferentiated thyroid or nonthyroid cells. Cotransduction of AdTTF-1 and AdTGTK permitted 90% cytotoxicity for BHP15-3 and >95% cytotoxicity for FRT, as well as for BHP7-13 and BHP18-21v thyroid cancer cell lines [both/TTF1(-)/TTF-2(-)/Pax-8(+)/TG(-)]. In contrast, little cytotoxicity was seen for H441 and MDCK cell lines even with 300 microg/ml of ganciclovir. These results suggest that cotransduction of a TG promoter-controlled suicide gene and the TTF-1 gene by adenoviral vectors confers transcriptionally targeted gene-mediated cytotoxicity in poorly differentiated thyroid carcinoma cells unable to express the TG gene.

Adenoviridae↗

PubMed2001

Influence of alkyl substitution on the gas-phase stability of 1-adamantyl cation and on the solvent effects in the solvolysis of 1-bromoadamantane.

1-Adamantyl cations having three methyl groups or one, two, or three isopropyl groups on the 3-, 5-, and 7-positions were found by FT ICR to be more stable than the 1-adamantyl cation and that the stability increases with the number of isopropyl group. The relative stabilities calculated by PM3 were in good agreement with the experimental results. In contrast, the sequence of the rates for the solvolysis in nonaqueous solvents are 3,5,7-(Me)(3)-1-AdBr < 1-bromoadamantane (1-AdBr) < 3,5,7-(n-Pr)(3)-1-AdBr < 3,5,7-(i-Pr)(3)-1-AdBr. The rates of solvolysis of 3,5,7-(i-Pr)(3)-1-AdBr and 3,5,7-(n-Pr)(3)-1-AdBr relative to 1-AdBr at 25 degrees C are 15 and 3.8 in EtOH, respectively, but markedly decreases with the increase in the amount of added water, reaching 0.84 and 0.15, respectively, in 60% EtOH. Reflecting these effects of water, the Grunwald-Winstein (GW) relationship for 3,5,7-(i-Pr)(3)-1-AdBr and 3,5,7-(n-Pr)(3)-1-AdBr against Y(Br) is linear for nonaqueous alcohols (EtOH, MeOH, TFE-EtOH, TFE, 97% HFIP), but marked downward deviations are observed for aqueous organic solvents, in particular, aqueous ethanol and aqueous acetone. The effect of the alkyl substituents to diminish relative solvolytic reactivity in EtOH-H(2)O mixtures may be ascribed to a blend of steric hindrance to Betarphinsted base-type hydration to the beta-hydrogens and hydrophobic interaction of the alkyl groups with ethanol to make the primary solvation shell less ionizing. The introduction of one nonyl group to the 3-position showed much smaller deviations in the GW relationship than the case of 3,5,7-(n-Pr)(3)-1-AdBr. The markedly decelerated solvolysis of alkylated 1-bromoadamantanes in aqueous organic solvents is a kinetic version of anomalously diminished dissociation of alkylbenzoic acids in aqueous ethanol and aqueous tert-butyl alcohol that was demonstrated by Wepster and co-workers a decade ago and ascribed to hydrophobic effects.

Journal Article↗

PubMed2001

Measurement of the B(e2) of (7)(lambda)Li and shrinkage of the hypernuclear size.

We report on the first measurement of a hypernuclear gamma-transition probability. gamma rays emitted in the E2(5/2(+)-->1/2(+)) transition of (7)(Lambda)Li were detected by a large-acceptance germanium detector array (Hyperball), and the lifetime of the parent state ( 5/2(+)) was determined by the Doppler shift attenuation method. The obtained result, 5.8(+0.9)(-0.7)+/-0.7 ps, was then converted into the reduced transition probability [ B(E2)] to be B(E2;5/2(+)-->1/2(+)) = 3.6+/-0.5(+0.5)(-0.4) e(2) fm(4). Compared with the B(E2) of the corresponding E2(3(+)-->1(+)) transition in the 6Li nucleus, our result gives evidence that the size of the 6Li core in (7)(Lambda)Li is smaller than the 6Li nucleus in the free space.

Journal Article↗

PubMed2001

Large-scale production of the carbohydrate portion of the sialyl-Tn epitope, alpha-Neup5Ac-(2-->6)-D-GalpNAc, through bacterial coupling.

Alpha-Neup5Ac-(2-->6)-D-GalpNAc, the carbohydrate portion of sialyl-Tn epitope of the tumor-associated carbohydrate antigen, was prepared by a whole-cell reaction through the combination of recombinant Escherichia coli strains and Corynebacterium ammoniagenes. Two recombinant E. coli strains overexpressed the CMP-Neup5Ac biosynthetic genes and the alpha-(2-->6)-sialyltransferase gene of Photobacterium damsela. C. ammoniagenes contributed to the production of UTP from orotic acid. Alpha-Neup5Ac-(2-->6)-D-GalpNAc was accumulated at 87 mM (45 g/L) after a 25-h reaction starting from orotic acid, N-acetylneuraminic acid, and 2-acetamide-2-deoxy-D-galactose.

Acetylgalactosamine↗

PubMed2001

NMR identification of the Tom20 binding segment in mitochondrial presequences.

Many mitochondrial proteins are synthesized in the cytosol as precursors with N-terminal presequences, and are imported into mitochondria with the aid of translocator protein complexes containing presequence-binding proteins. Tom20, a receptor protein which functions in an early step of the mitochondrial protein import, recognizes presequences with divergent amino acid sequences. Here, we report the identification of the segments involved in binding to Tom20 in mitochondrial presequences. We monitored the chemical shift perturbation of the NMR signals of five different 15N-labeled presequence peptides by the addition of the cytosolic receptor domain of rat or yeast Tom20. The perturbed segments occupy different positions, either near the N terminus or at the C terminus, in the presequences. Spin label experiments revealed that this is not due to different orientations of the presequence peptides bound to Tom20. The results presented here will offer a starting point to perform detailed analyses of Tom20-binding elements by systematic amino acid replacements.

Amino Acid Sequence↗

PubMed2001

Structural characteristics of the N-glycans of two isoforms of prostate-specific antigens purified from human seminal fluid.

Prostate-specific antigen (PSA) is a glycosylated chymotrypsin-like serine protease and is found mainly in prostatic tissue and seminal fluid. We purified two forms of PSA (PSA-A and PSA-B) from human seminal fluid with pI values of approx. 7.2 and approx. 6.9, respectively. To characterize the N-glycans of the two isoforms, the sugar chains were liberated by hydrazinolysis followed by N-acetylation, and derivatized with 2-aminobenzamide. Both PSA-A and PSA-B contained mono- and disialylated sugar chains, although PSA-B had a much higher content of the latter. After removal of sialic acid residues by sialidase digestion, mono- and biantennary N-glycans and three outer chain moieties (Galbeta1-4GlcNAcbeta1-, GlcNAcbeta1-, GalNAcbeta1-4GlcNAcbeta1-) were found in both samples. However, the ratios of each N-glycan were different. These results indicate that PSA-A and PSA-B differ not only in their sialic acid contents, but also in their outer chain features.

Carbohydrate Sequence↗

PubMed2001

Profenofos metabolites in human poisoning.

Profenofos and its metabolites were determined in a case of fatal poisoning. Little profenofos and large amounts of metabolites were detected by gas chromatography/flame photometric detection in the acid extracts of blood and urine after methylation with diazomethane. Four major metabolites containing phosphorus were identified with the synthesized metabolites, namely, despropylated profenofos, desethylated profenofos and des-S-propylated profenofos, respectively. 4-Bromo-2-chlorophenol (BCP), an aryl moiety of profenofos, was also determined in blood and urine with high performance liquid chromatograph (HPLC) as free or conjugated metabolites.

Aged↗

PubMed2001

A novel neural Wiskott-Aldrich syndrome protein (N-WASP) binding protein, WISH, induces Arp2/3 complex activation independent of Cdc42.

We identified a novel adaptor protein that contains a Src homology (SH)3 domain, SH3 binding proline-rich sequences, and a leucine zipper-like motif and termed this protein WASP interacting SH3 protein (WISH). WISH is expressed predominantly in neural tissues and testis. It bound Ash/Grb2 through its proline-rich regions and neural Wiskott-Aldrich syndrome protein (N-WASP) through its SH3 domain. WISH strongly enhanced N-WASP-induced Arp2/3 complex activation independent of Cdc42 in vitro, resulting in rapid actin polymerization. Furthermore, coexpression of WISH and N-WASP induced marked formation of microspikes in Cos7 cells, even in the absence of stimuli. An N-WASP mutant (H208D) that cannot bind Cdc42 still induced microspike formation when coexpressed with WISH. We also examined the contribution of WISH to a rapid actin polymerization induced by brain extract in vitro. Arp2/3 complex was essential for brain extract-induced rapid actin polymerization. Addition of WISH to extracts increased actin polymerization as Cdc42 did. However, WISH unexpectedly could activate actin polymerization even in N-WASP-depleted extracts. These findings suggest that WISH activates Arp2/3 complex through N-WASP-dependent and -independent pathways without Cdc42, resulting in the rapid actin polymerization required for microspike formation.

Actin-Related Protein 2↗

PubMed2001

Mnl1p, an alpha -mannosidase-like protein in yeast Saccharomyces cerevisiae, is required for endoplasmic reticulum-associated degradation of glycoproteins.

The endoplasmic reticulum (ER) has a mechanism to block the exit of misfolded or unassembled proteins from the ER for the downstream organelles in the secretory pathway. Misfolded proteins retained in the ER are subjected to proteasome-dependent degradation in the cytosol when they cannot achieve correct folding and/or assembly within an appropriate time window. Although specific mannose trimming of the protein-bound oligosaccharide is essential for the degradation of misfolded glycoproteins, the precise mechanism for this recognition remains obscure. Here we report a new alpha-mannosidase-like protein, Mnl1p (mannosidase-like protein), in the yeast ER. Mnl1p is unlikely to exhibit alpha1,2-mannosidase activity, because it lacks cysteine residues that are essential for alpha1,2-mannosidase. However deletion of the MNL1 gene causes retardation of the degradation of misfolded carboxypeptidase Y, but not of the unglycosylated mutant form of the yeast alpha-mating pheromone. Possible roles of Mnl1p in the degradation and in the ER-retention of misfolded glycoproteins are discussed.

Amino Acid Sequence↗