Biomedical subjects

Y Takei

Publications and source records attributed to Y Takei.

At least 55 records · Page 3Linked to original sources

PubMed2001

Rhabdomyolysis triggered by an asthmatic attack in a patient with McArdle disease.

We describe a patient with McArdle disease who developed rhabdomyolysis triggered by a bronchial asthmatic attack. A 64-year-old man had chronic pulmonary emphysema with asthma, and an asthmatic attack led to severe rhabdomyolysis that required continuous hemodiafiltration. After 2 years, a physical examination revealed atrophy of the extremities compared with previous examinations, especially of the intercostal muscles. During that time, he suffered two severe bronchial asthmatic attacks. His serum level of creatinine kinase remained between 4,000 and 7,000 IU/l when he did not suffer from asthmatic attacks and rhabdomyolysis had abated. Therefore, we suspected that his recent muscle atrophy was caused by asthmatic attacks, and discussed the possibility of his respiratory muscle weakness due to McArdle disease in relation to his severe bronchial asthmatic attacks as well as chronic obstructive pulmonary disease.

Asthma↗

PubMed2001

Recurrent cerebral embolism in a familial amyloid polyneuropathy patient who received partial liver transplantation from a living donor.

Cerebral embolism in relation to cardiac amyloidosis has not been widely noted. A 47-year-old woman who had been suffering from familial amyloid polyneuropathy (FAP) for 7 years was treated with partial liver transplantation from a living donor and her early postoperative course was uneventful. During the 391st to 613th postoperative day she experienced recurrent cerebral infarctions, but clinical examinations revealed no disorders capable of producing cerebral embolism. At autopsy splenic infarction and intracardiac thrombi adhering to the mitral valve and left atrium were found, and these areas showed severe amyloid deposition. Amyloid heart is considered to be one possible cause of systemic embolism.

Amyloid Neuropathies↗

PubMed2001

Hypothalamic encephalitis with bradycardia.

A 74-year-old man developed fever, somnolence, hyponatremia, and life-threatening sinus bradycardia for three weeks. He showed a slight elevation of lymphocyte count and protein level in the cerebrospinal fluid. A brain CT scan revealed a diffuse low density area around the hypothalamus which was identified as a high intensity signal by flair MR imaging. Marked sinus bradycardia developed with no abnormality in the echocardiograph or cardiac enzymes. Over the next 6 weeks he became alert and normal sinus rhythm resumed. The results of endocrine tests were compatible with hypothalamic insufficiency with partial hypopituitarism and the syndrome of inappropriate secretion of ADH.

Aged↗

PubMed2001

Various cooking methods and the flavonoid content in onion.

Onion is a major source of flavonoids and is cooked in various ways in the world. The major flavonoids in onion are two quercetin glycosides, quercetin 4'-O-beta-glucoside (Q4'G) and quercetin 3,4'-O-beta-diglucosides (Q3,4'G), which are recognized as bioactive substances that are good for our health. We have investigated the effect of cooking procedures on the content of antioxidants. We selected quercetin conjugates, total phenol compounds, and ascorbic acid to estimate the amount of flavonoid ingestion from onion. We examined the following cooking methods: boiling, frying with oil and butter, and microwave cooking. Various cooking methods do not consider the degradation of quercetin conjugates when cooking onion. Microwave cooking without water better retains flavonoids and ascorbic acid. Frying does not affect flavonoid intake. The boiling of onion leads to about 30% loss of quercetin glycosides, which transfers to the boiling water. At that time, the effect of additives on the quercetin conjugates is different according to the compounds. The hydrolysis of quercetin glycosides for daily cooking might occur with the addition of seasonings such as glutamic acid. Additional ferrous ions accelerated the loss of flavonoids.

Antioxidants↗

PubMed2001

[Post-genome challenges against inflammatory bowel diseases].

Advancement of genome analysis might give great impact to the treatment of inflammatory bowel diseases(IBD). IBD patients are treated by sulfadrugs, steroids and anti-immune drugs. For difficult cases, leukocytapheresis, beclomethasone dipropionate, anti-TNF therapy, anti-LTB4 therapy and other new methods are applied. Developing epoch-making drugs will be achieved by finding new molecular targets. Histologic identification of dysplasia is important in the surveillance of long-standing ulcerative colitis. The molecular diagnosis is required for the distinction of dysplasia from the regenerative inflammatory changes. P53 immunostaining have been proved useful. Various molecular targets will be taken into discussion as additional procedures. Recent genome analysis have revealed some genetic factors contribute to pathogenesis of IBD, which are HLA, IL4, MUC3, IBD1 locus, IBD2 locus and so on. More information about genes concerning IBD will be provided by analyzing dense SNP map using DNA tip. They will open the way to the tailored therapy.

Biomarkers↗

PubMed2001

Comparative molecular biology of natriuretic peptide receptors.

Analysis of the mammalian natriuretic peptide system has established the presence of three types of receptors with distinct structural and functional features and tissue distributions. To clarify the physiological role of each subtype, we studied the natriuretic peptide system in animals with specialized anatomical and physiological features. In this review, following a brief description of the comparative and evolutionary aspects of the ligands, we will analyze the structure and distribution of natriuretic peptide receptors in lower vertebrates, as well as those of rats with essential and salt-sensitive hypertension, and discuss the evolutionary aspects of the natriuretic peptide systems in mammals and fishes. Emphasis is placed on our series of studies with eel receptors that revealed (i) interesting variations in the pattern of intra- and inter-molecular disulfide bonding; (ii) dense chondrocyte localization of NPR-C, which opened a new field of study for natriuretic peptides and bone metabolism; and (iii) the presence of a new receptor subtype, NPR-D, which is abundant in the brain and a member of the receptor subfamily with a short cytoplasmic C-terminal tail.

Amino Acid Sequence↗

PubMed2001

Long-term alcohol exposure changes sensitivity of rat Kupffer cells to lipopolysaccharide.

BACKGROUND: Chronic ethanol treatment enhances Kupffer cell sensitivity to lipopolysaccharide (LPS). In this model, CD14 in Kupffer cells was increased significantly 4 weeks after ethanol. Moreover, it was shown that prostaglandin E2 produced by activated Kupffer cells participated in the mechanism of ethanol-induced fatty liver. This study was designed to elucidate the temporal effect of chronic ethanol exposure on Kupffer cell sensitization to LPS. METHODS: Rats were given ethanol every 24 hr intragastrically for up to 12 weeks, and Kupffer cells were isolated 24 hr after the final ethanol administration and cultured in RPMI 1640 with 10% fetal bovine serum. After addition of LPS to Kupffer cells, intracellular calcium ([Ca2+]i) was measured. RESULTS: CD14 in Kupffer cells was increased approximately 2-fold, and then it decreased and returned to control levels. The LPS-induced increases in [Ca2+]i and tumor necrosis factor-alpha by Kupffer cells were also increased approximately 3-fold over control values, but they also returned to control levels. Triglyceride content increased with the duration of chronic ethanol treatment. At 8 weeks, prostaglandin E2 produced by Kupffer cells increased approximately 3-fold over control values and triglycerides by approximately 4-fold before gradually decreasing to basal levels. After 12 weeks of ethanol exposure, LPS-induced increases in [Ca2+]i and tumor necrosis factor-alpha production were only approximately 50% as high as peak levels at 4 weeks. Liver triglyceride content at 12 weeks was reduced significantly compared with values at 8 weeks. CONCLUSIONS: Kupffer cells at the early stage of chronic ethanol exposure exhibited sensitization to LPS, but this sensitivity was blunted later. This correlated with triglyceride accumulation in the liver. These data indicate that long-term alcohol exposure changes the sensitivity of rat Kupffer cells to LPS but that the magnitude of the effect is time dependent.

Animals↗

PubMed2001

[Placement of the inferior vena cava filter proximal to the renal vein in a patient with left-sided inferior vena cava complicated by pulmonary embolism: a case report].

A 55-year-old man was admitted to our hospital complaining of dyspnea and chest pain. Transthoracic echocardiography showed dilation of the right ventricle. Chest computed tomography with contrast medium showed multiple emboli in the pulmonary arteries. Venography of the lower extremities showed multiple thrombi in the right popliteal vein and the presence of left-sided vena cava. This unusual case of left-sided vena cava was complicated by deep vein thrombosis due to hemostasis. A Greenfield filter was placed in the vena cava proximal to the right renal vein in a right internal jugular vein approach.

Humans↗

PubMed2000

Multiplicity, structures, and endocrine and exocrine natures of eel fucose-binding lectins.

Lectins, a group of proteins that bind to cell surface carbohydrates and play important roles in innate immunity, are widely used experimentally to distinguish cell types and to induce cell proliferation. Eel serum lectins have been useful as anti-H hemagglutinins and also in lectin histochemistry as fucose-binding lectins (fucolectins), but their structures have not been determined. Here we report the primary structures and the sites of synthesis of eel fucolectins. Eel serum fucolectins were separated by two-dimensional gel electrophoresis and sequenced. cDNA cloning, based on the amino acid sequence information, and Northern blot analysis indicated that 1) the fucose-binding lectins are secretory proteins and have unique structures among the lectins, exhibiting only weak similarities to frog pentraxin, horseshoe crab tachylectin-4, and fly fw protein; 2) there are at least seven closely related members; and 3) their messages are abundantly expressed in the liver and in significant levels in the gill and intestine. The lectin-producing hepatic cells were identified by immunostaining; in the gill, exocrine mucous cells were stained, suggesting that serum fucolectins derive from the liver. Using primary culture of eel hepatocytes, the message levels were shown to be increased by lipopolysaccharide, suggesting a role for fucolectins in host defense. SDS-polyacrylamide gel electrophoresis analysis showed that eel fucolectins have a SDS-resistant tetrameric structure consisting of two disulfide-linked dimers.

Amino Acid Sequence↗

PubMed2000

Defects in axonal elongation and neuronal migration in mice with disrupted tau and map1b genes.

Tau and MAP1B are the main members of neuronal microtubule-associated proteins (MAPs), the functions of which have remained obscure because of a putative functional redundancy (Harada, A., K. Oguchi, S. Okabe, J. Kuno, S. Terada, T. Ohshima, R. Sato-Yoshitake, Y. Takei, T. Noda, and N. Hirokawa. 1994. Nature. 369:488-491; Takei, Y., S. Kondo, A. Harada, S. Inomata, T. Noda, and N. Hirokawa. 1997. J. Cell Biol. 137:1615-1626). To unmask the role of these proteins, we generated double-knockout mice with disrupted tau and map1b genes and compared their phenotypes with those of single-knockout mice. In the analysis of mice with a genetic background of predominantly C57Bl/6J, a hypoplastic commissural axon tract and disorganized neuronal layering were observed in the brains of the tau+/+map1b-/- mice. These phenotypes are markedly more severe in tau-/-map1b-/- double mutants, indicating that tau and MAP1B act in a synergistic fashion. Primary cultures of hippocampal neurons from tau-/-map1b-/- mice showed inhibited axonal elongation. In these cells, a generation of new axons via bundling of microtubules at the neck of the growth cones appeared to be disturbed. Cultured cerebellar neurons from tau-/-map1b-/- mice showed delayed neuronal migration concomitant with suppressed neurite elongation. These findings indicate the cooperative functions of tau and MAP1B in vivo in axonal elongation and neuronal migration as regulators of microtubule organization.

Aging↗

PubMed2000

A ribonucleotide reductase gene involved in a p53-dependent cell-cycle checkpoint for DNA damage.

The p53 gene is frequently inactivated in human cancers. Here we have isolated a p53-inducible gene, p53R2, by using differential display to examine messenger RNAs in a cancer-derived human cell line carrying a highly regulated wild-type p53 expression system. p53R2 contains a p53-binding sequence in intron 1 and encodes a 351-amino-acid peptide with striking similarity to the ribonucleotide reductase small subunit (R2), which is important in DNA synthesis during cell division. Expression of p53R2, but not R2, was induced by ultraviolet and gamma-irradiation and adriamycin treatment in a wild-type p53-dependent manner. Induction of p53R2 in p53-deficient cells caused G2/M arrest and prevented cells from death in response to adriamycin. Inhibition of endogenous p53R2 expression in cells that have an intact p53-dependent DNA damage checkpoint reduced ribonucleotide reductase activity, DNA repair and cell survival after exposure to various genotoxins. Our results indicate that p53R2 encodes a ribonucleotide reductase that is directly involved in the p53 checkpoint for repair of damaged DNA. The discovery of p53R2 clarifies a relationship between a ribonucleotide reductase activity involved in repair of damaged DNA and tumour suppression by p53.

Amino Acid Sequence↗

PubMed2000

Viability of Q-wave infarcted myocardium with restored positive and persistent negative T waves after optimal revascularization compared with dobutamine stress echocardiography.

To clarify the clinical difference in viability of myocardium with negative and positive T waves in Q-wave anterior or anteroseptal myocardial infarction, we performed low-dose dobutamine stress echocardiography in 17 patients with negative T waves and in 13 patients with positive T waves with optimal revascularization of infarct-related arteries in the chronic phase of infarction. At baseline the wall motion score (WMS) of the negative and positive T groups was 25.8 +/- 3.0 and 22.3 +/- 2.2 points (p <0.05), respectively. At peak stress WMS in each group was 27.2 +/- 4.2 and 19.8 +/- 2.4 points (p <0.0001), respectively. With dobutamine stress WMS in the positive T group was more decreased than that of the negative T group (p <0.0001). We conclude that the restored positive T waves in Q-wave myocardial infarction indicate a significantly greater amount of viable myocardium than the negative T waves, showing better regional wall motion improvement with low-dose dobutamine stress.

Aged↗

PubMed2000

Isolation and characterization of a novel TP53-inducible gene, TP53TG5, which suppresses growth and shows cell cycle-dependent transition of expression.

Through a strategy of direct cloning of TP53-binding DNA sequences from human genome DNA, we have identified a novel TP53-target gene, termed TP53TG5 (TP53-target gene 5). This gene, localized to chromosome band 20q13.1 by fluorescence in situ hybridization, encodes a 290-amino-acid peptide with no significant homology with any known proteins in the public database. A colony-formation assay using human glioblastoma cell line T98G, which lacks wild-type TP53 and expresses no endogenous TP53TG5, revealed a growth-suppressive effect of the TP53TG5 gene product. Furthermore, immunohistochemical studies, following transfection of T98G with plasmid designed to express green fluorescent protein-fused TP53TG5, revealed cell cycle-dependent intracellular localization of this protein. Our results suggest that functional studies of TP53TG5 may provide new insights into the complex physiological activities of TP53.

Adaptor Proteins, Signal Transducing↗

PubMed2000

Taurine preserves gap junctional intercellular communication in rat hepatocytes under oxidative stress.

Gap junctional intercellular communication (GJIC) between hepatocytes is important for the maintenance of differentiated liver functions. Taurine is known to be cytoprotective, and is used clinically to improve liver functions. We evaluated the effect of taurine on GJIC in hepatocyte doublets under oxidative stress. Hepatocyte doublets were isolated from female Wistar rats, using a collagenase perfusion technique, and cultured in Leibovitz-15 medium containing fetal bovine serum (10%). H2O2 (2 mM) and/or taurine (0.1-1 mM) were added 2 h after inoculation, and the culture was incubated for 3 h. Fluorescent dye (Lucifer Yellow CH) coupling between adjacent cells was evaluated by microinjection. The distribution and quantity of connexin 32 (Cx32) in hepatocytes were detected using indirect immunofluorescence analysis and Western blotting. Steady state mRNA levels of Cx32 were detected by Northern blotting. The percentage of dye coupling 5 h after inoculation was 88 +/- 6.3% in the control. however, this was decreased to almost half the control value by H2O2. Taurine prevented the decrease caused by H2O2 in a dose-dependent manner. Immunofluorescence analysis for Cx32 demonstrated numerous punctate fluorescent spots along the intercellular plasma membrane in controls, which were significantly decreased by H2O2. Taurine prevented the decrease of Cx32. Western blot analysis also showed the decrease of Cx32 protein levels by H2O2 treatment, which decrease was prevented by taurine. Interestingly, H2O2 and/or taurine treatments did not affect Cx32 mRNA levels. Our findings indicated that H2O2 treatment decreased GJIC between hepatocytes, most likely due to augmenting the degradation of Cx32 proteins, whereas taurine prevented this process. This effect of taurine is beneficial for the preservation of differentiated functions in the liver under oxidative stress.

Animals↗

PubMed2000

Structural and functional evolution of the natriuretic peptide system in vertebrates.

The natriuretic peptide (NP) system consists of three types of hormones [atrial NP (ANP), brain or B-type NP (BNP), and C-type NP (CNP)] and three types of receptors [NP receptor (R)-A, NPR-B, and NPR-C]. ANP and BNP are circulating hormones secreted from the heart, whereas CNP is basically a neuropeptide. NPR-A and NPR-B are membrane-bound guanylyl cyclases, whereas NPR-C is assumed to function as a clearance-type receptor. ANP, BNP, and CNP occur commonly in all tetrapods, but ventricular NP replaces BNP in teleost fish. In elasmobranchs, only CNP is found, even in the heart, suggesting that CNP is an ancestral form. A new guanylyl cyclase-uncoupled receptor named NPR-D has been identified in the eel in addition to NPR-A, -B, and -C. The NP system plays pivotal roles in cardiovascular and body fluid homeostasis. ANP is secreted in response to an increase in blood volume and acts on various organs to decrease both water and Na+, resulting in restoration of blood volume. In the eel, however, ANP is secreted in response to an increase in plasma osmolality and decreases Na+ specifically, thereby promoting seawater adaptation. Therefore, it seems that the family of NPs were originally Na(+)-extruding hormones in fishes; however, they evolved to be volume-depleting hormones promoting the excretion of both Na+ and water in tetrapods in which both are always regulated in the same direction. Vertebrates expanded their habitats from fresh water to the sea or to land during evolution. The structure and function of osmoregulatory hormones have also undergone evolution during this ecological evolution. Thus, a comparative approach to the study of the NP family affords new insights into the essential function of this osmoregulatory hormone.

Amino Acid Sequence↗

PubMed2000

Efficacy of reduced dosage of rabeprazole in PPI/AC therapy for Helicobacter pylori infection: comparison of 20 and 40 mg rabeprazole with 60 mg lansoprazole.

Proton pump inhibitor (PPI)- based triple therapy has been a recent trend for treatment of Helicobacter pylori infection, with the PPI-amoxicillin-clarithromycin (PPI/AC) regimen being one of the most popular. We have reported the effectiveness of PPI/AC regimens in the Japanese population and have demonstrated that the effectiveness of 40 mg rabeprazole, a recently developed PPI, is similar to that of 40 mg of omeprazole and 60 mg of lansoprazole when used in combination with amoxicillin and clarithromycin. In this study, we focused on whether 20 mg of rabeprazole is effective in our patient population by comparing that dosage with 40 mg of rabeprazole and 60 mg of lansoprazole. In all, 308 H. pylori-infected patients [236 men and 72 women; age (mean +/- SEM) 49.3+/-0.6 years] with peptic ulcer disease (N = 270) or nonulcer dyspepsia (N = 38) were randomly assigned to one of three different PPI/AC regimens for seven days: LAC (N = 104), consisting of lansoprazole 30 mg twice a day, amoxicillin 500 mg three times a day, and clarithromycin 200 mg twice a day; RAC (N = 104), consisting of rabeprazole 20 mg twice a day, amoxicillin 500 mg three times a day, and clarithromycin 200 mg twice a day; and the R1/2AC regimen (N = 100), which included rabeprazole 10 mg twice a day, amoxicillin 500 mg three times a day, and clarithromycin 200 mg twice a day. Cure of the infection was determined by the [13C]urea breath test one month after completion of the treatment. Intention-to-treat based and per-protocol based cure rates for the LAC, RAC, and R1/2AC regimens were 82.7 (95% CI, 74-89) and 88.7% (81-94), 85.6 (77-92) and 89.8% (82-95), and 87.0 (79-93) and 89.7% (82-95), respectively. Although adverse effects were reported by 20.3% of the patients, these affected compliance in only five patients in the RAC and LAC regimens and none in the R1/2AC group. Overall complete compliance was achieved in 94.7% of interviewed patients. In conclusion, the effectiveness of the PPI/AC regimen with 20 mg of rabeprazole is comparable with and even safer than that of 40 mg of rabeprazole and 60 mg of lansoprazole in our patient population.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2000

Characterization of dihydropyrimidine dehydrogenase on immunohistochemistry in colon carcinoma, and correlation between immunohistochemical score and protein level or messenger RNA expression.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD) is the first enzyme that metabolizes 5-fluorouracil (5-FU). Until now, enzymatic activity or mRNA expression of DPD has been investigated. However, there are no papers on immunohistochemical evaluation of DPD. We investigated DPD staining on immunohistochemistry, and examined the relationship among immunohistochemical score, protein level and mRNA expression of DPD. MATERIALS AND METHODS: Forty-seven resected colon cancer specimens, four colon cancer cell lines, two xenografts by colon cancer cell lines, and human mononuclear cells were used. Immunohistochemistry was performed using DPD monoclonal antibody. Protein levels were determined by Western blot analysis. And mRNA levels were calculated by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: DPD was strongly expressed in the cytoplasm of cancer cells, and in the cytoplasm of macrophage and plasma cells. The immunohistochemical score was more correlated with protein levels (P = 0.0054) than mRNA expression (P = 0.9028). CONCLUSIONS: We investigated the characterization of DPD immunohistochemically, and showed that immunohistochemical expression of DPD can be used to predict the sensitivity of colorectal carcinomas to 5-FU.

Aged↗

PubMed2000

Enantioselective uptake of amino acid with overoxidized polypyrrole colloid templated with L-lactate.

An overoxidized polypyrrole colloid, which can recognise enantiomers of amino acids has been prepared by a newly developed molecular imprinting technique. A polypyrrole colloid, which had been polymerised from a mixture of pyrrole (monomer), polyvinylpyrrolidone (steric stabiliser), peroxodisulfate (oxidant) and L-lactate (dopant), was overoxidized to create a dopant-complementary cavity. The enantioselectivity of the overoxidized colloid was evaluated by comparing the uptake of L-alanine and L-cysteine with that of the respective D-enantiomers. The L/D uptake ratios for these amino acids were about 2, while phenylalanine showed suppressed uptake for both the enantiomers. The absence of phenylalanine uptake can be explained in terms of the molecular size, which is too large to be accommodated by the cavity created by L-lactate. In contrast, a colloid templated with L-phenyllactate took up L-phenylalanine with a higher enantioselectivity of about 7. A colloid templated with L-lactate was applied to surface chirality analysis through enantioselective adsorption on cysteine-modified gold surfaces. Quartz microbalance experiments and scanning electron microscope observation of the gold surface revealed that the colloidal particle has higher affinity to a surface modified with L-cysteine than to one modified with D-cysteine.

Amino Acids↗