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Biomedical subjects

Takashi Hashimoto

Publications and source records attributed to Takashi Hashimoto.

At least 55 records · Page 3Linked to original sources
PubMed2004

SPIRAL1 encodes a plant-specific microtubule-localized protein required for directional control of rapidly expanding Arabidopsis cells.

Highly organized interphase cortical microtubule (MT) arrays are essential for anisotropic growth of plant cells, yet little is known about the molecular mechanisms that establish and maintain the order of these arrays. The Arabidopsis thaliana spiral1 (spr1) mutant shows right-handed helical growth in roots and etiolated hypocotyls. Characterization of the mutant phenotypes suggested that SPR1 may control anisotropic cell expansion through MT-dependent processes. SPR1 was identified by map-based cloning and found to encode a small protein with unknown function. Proteins homologous to SPR1 occur specifically and ubiquitously in plants. Genetic complementation with green fluorescent protein fusion proteins indicated that the SPR1 protein colocalizes with cortical MTs and that both MT localization and cell expansion control are conferred by the conserved N- and C-terminal regions. Strong SPR1 expression was found in tissues undergoing rapid cell elongation. Plants overexpressing SPR1 showed enhanced resistance to an MT drug and increased hypocotyl elongation. These observations suggest that SPR1 is a plant-specific MT-localized protein required for the maintenance of growth anisotropy in rapidly elongating cells.

Arabidopsis↗
PubMed2004

Intraportal nicotine infusion in rats decreases hepatic blood flow through endothelin-1 and both endothelin A and endothelin B receptors.

Smoking has been demonstrated to aggravate liver injury. Nicotine, a major pharmacological component of tobacco smoke, affects a multitude of functions. Smoking and nicotine induce synthesis of endothelin (ET)-1. The effect of intraportal infusion of nicotine on hepatic circulation and an involvement of ET-1 and ET receptor in the action of nicotine were investigated in rats. Nicotine (0-100 microg/kg/h) was infused into the portal vein of urethane-anesthetized rats, and changes of hepatic blood flow were evaluated. Intraportal infusion of nicotine dose-dependently decreased hepatic blood flow and increased portal pressure without any alteration of heart rate or arterial blood pressure. This action of intraportal nicotine was completely abolished by pretreatment of ET-1 antibody. Either BQ485 (ET(A) receptor antagonist) or BQ788 (ET(B) receptor antagonist) partially reversed the effect of nicotine, and combination of BQ788 and BQ485 completely abolished it. These findings suggest that nicotine inhibits hepatic circulation through ET-1, and ET(A) and ET(B) receptor.

Animals↗
PubMed2004

Humoral responses to peptides correlate with overall survival in advanced cancer patients vaccinated with peptides based on pre-existing, peptide-specific cellular responses.

PURPOSE: The aim of this study is to find a laboratory marker for overall survival in advanced cancer patients who were vaccinated with peptides based on pre-existing, peptide-specific CTL precursors in the circulation. EXPERIMENTAL DESIGN: A group of 113 patients with advanced cancer (28 colorectal, 22 prostate, 15 lung, 14 gastric, and 34 other cancers) was enrolled in a Phase I clinical study of peptide vaccination in which peptide-specific CTL precursors of prevaccination peripheral blood mononuclear cells were measured, followed by vaccination with these peptides (maximum of four). For cellular responses, pre and postvaccination (sixth) peripheral blood mononuclear cells were provided for measurement of both peptide-specific CTL precursors by IFN-gamma release assay and tumor reactivity by (51)Cr release assay. Delayed type hypersensitivity was also measured. For humoral response, pre and postvaccination (sixth) sera were provided for measurement of peptide-reactive IgG by an ELISA. RESULTS: The median survival time and 1-year survival rate of the total cases were 346 +/- 64.9 days and 44.6%, respectively, and those of patients vaccinated more than six times (n = 91) were 409 +/- 15 days and 54.4%, respectively. In these 91 patients, the overall survival of patients whose sera showed increased levels of peptide-reactive IgG (n = 60) was significantly more prolonged (P = 0.0003) than that of patients whose sera did not (n = 31), whereas none of cellular responses correlated with overall survival. CONCLUSIONS: Peptide-specific IgG in postvaccination sera could be a suitable laboratory maker for the prediction of prolonged survival in advanced cancer patients vaccinated with peptides based on pre-existing CTL precursors.

Adult↗
PubMed2004

PPARgamma mediates NSAIDs-induced upregulation of TFF2 expression in gastric epithelial cells.

Trefoil factor family (TFF) is a group of peptides that play critical roles in maintaining gastric mucosal integrity. In real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and reporter gene assays, we show that indomethacin and aspirin upregulate TFF2 expression in MKN45 gastric cells. These drugs also activated peroxisome proliferator-activated receptor gamma (PPARgamma) at concentration ranges that increase TFF2 expression, and upregulated TFF2 expression was suppressed by GW9662, a specific inhibitor of PPARgamma. These results suggest that indomethacin and aspirin upregulate gastric expression of TFF2 through activation of PPARgamma. This mechanism may be important in reducing the extent of gastric mucosal injury caused by the administration of non-steroidal anti-inflammatory drugs (NSAIDs).

Anilides↗
PubMed2004

Antibody titers to desmogleins 1 and 3 in a patient with paraneoplastic pemphigus associated with follicular dendritic cell sarcoma.

BACKGROUND: Most paraneoplastic pemphigus (PNP) cases reported to date have been associated with lymphoproliferative neoplasms. Patients with PNP have autoantibodies against the plakin family (eg, envoplakin and periplakin). Antibodies against desmoglein 3 (Dsg3) and Dsg1, antigens for classic types of pemphigus, have also been reported to play an important role in the initial stage of PNP. OBSERVATIONS: We describe a patient with PNP associated with follicular dendritic cell sarcoma. Antibodies to envoplakin and periplakin were detected. When only mucosal lesions were observed at the early stage, the antibody to Dsg3 but not to Dsg1 was detected by enzyme-linked immunosorbent assay. After skin lesions appeared, antibodies to Dsg1 and Dsg3 were detected. These titers were elevated, with exacerbation of skin lesions. Although the patient received corticosteroid therapy, double-filtration plasmapheresis, and intravenous human immunoglobulin therapy after surgical resection of follicular dendritic cell sarcoma, she died of fungal infective lung embolisms. A direct immunofluorescence study of autopsy samples showed IgG deposition in the epidermis of the skin and oral mucosal membrane, but not in the lungs and kidneys and follicular dendritic cell sarcoma of the para-aortic area. CONCLUSION: In this patient with PNP and follicular dendritic cell sarcoma, there was an association between the clinical phenotype and the anti-Dsg antibody profile, as seen in pemphigus vulgaris.

Antibodies↗
PubMed2004

Anti-obesity actions of green tea: possible involvements in modulation of the glucose uptake system and suppression of the adipogenesis-related transcription factors.

To investigate mechanisms of the anti-obesity actions of green tea in vivo, rats were given green tea instead of drinking water for 3 weeks. It was confirmed that green tea reduced adipose tissue weight without any change in body weight, other tissue weights, and food and water intakes. Green tea also significantly reduced the plasma levels of cholesterols and free fatty acids. Certain catechins existed in the plasma at 0.24 microM under our experimental conditions, though most of them existed as conjugated forms. For mechanisms of the anti-obesity actions, green tea significantly reduced glucose uptake accompanied by a decrease in translocation of glucose transporter 4 (GLUT4) in adipose tissue, while it significantly stimulated the glucose uptake with GLUT4 translocation in skeletal muscle. Moreover, green tea suppressed the expression of peroxisome proliferator-activated receptor gamma and the activation of sterol regulatory element binding protein-1 in adipose tissue. In conclusion, green tea modulates the glucose uptake system in adipose tissue and skeletal muscle and suppresses the expression and/or activation of adipogenesis-related transcription factors, as the possible mechanisms of its anti-obesity actions.

Adipose Tissue↗
PubMed2004

Lentinan from shiitake mushroom (Lentinus edodes) suppresses expression of cytochrome P450 1A subfamily in the mouse liver.

Induction of xenobiotics metabolizing enzymes is related to the formation and chemoprevention of cancer. Since cytochrome P450s (CYPs) including CYP1A subfamily metabolize certain pro-carcinogens to their ultimate forms, down-regulation of CYP1As by food factors leads to the prevention of cancer. Mushroom polysaccharides, especially beta-glucans such as lentinan from Lentinus edodes, possess the anti-tumor and immunomodulating activities through the cytokine production from immunocytes. Recent our studies have demonstrated that lentinan suppresses hepatic CYP1As expression in the both constitutive and inducible levels through the production of tumor necrosis factor-alpha and an increase in the DNA-binding activity of nuclear factor-kappaB. This paper discusses on the effective lentinan dosage and route of administration for suppression of CYP1As.

Animals↗
PubMed2004

Postoperative corticosteroid therapy for bile drainage in biliary atresia--a nationwide survey.

PURPOSE: Members of the Japanese Biliary Atresia Society were surveyed to determine their current practice regarding early use of corticosteroids after Kasai's operation. METHODS: Questions included the patient's background data, dosage, timing, complications, and outcome. Anicteric survival with the native liver was statistically compared between groups categorized by steroid dosage using Kaplan-Meier analysis. RESULTS: Among 54 institutions surveyed, a total of 222 patients with uncorrectable BA were collected from 34 responders, including 208 patients who received steroid therapy and 14 without it. Prednisolone was started during the first postoperative week in 31% and during the second week in 64%. Perforation and peritonitis occurred in 1 patient given 3 mg/kg/d of prednisolone on postoperative day 1. The survival rates of the steroid and nonsteroid groups were 58.0% and 35.7%, respectively (P = .052). The initial dose of prednisolone was or=4.0 mg/kg/d in 108 patients. The survival rates of the group receiving >or=4.0 mg/kg/d and the nonsteroid group were 58.9% and 35.7%, respectively (P = .0494). CONCLUSIONS: (1) Most surgeons use steroids. (2) Although the anicteric survival rate was higher in the steroid group, the number of patients in the nonsteroid group was too small to draw conclusions. (3) The recommended initial steroid dose is >or=4.0 mg/kg/d. (4) Complications are uncommon if administration is not started too early.

Adrenal Cortex Hormones↗
PubMed2004

Microtubule defects and cell morphogenesis in the lefty1lefty2 tubulin mutant of Arabidopsis thaliana.

lefty1 and lefty2 are semi-dominant left-handed helical growth mutants of Arabidopsis thaliana, which result from identical dominant-negative amino acid substitutions in alpha-tubulin 6 and alpha-tubulin 4, respectively. Here we characterized the expression patterns of the affected tubulin genes and the phenotypes of the lefty double mutant to address increasing effects of microtubule defects on cell morphogenesis. Both tubulin genes were expressed ubiquitously in examined tissue and cell types, and the alpha-tubulin 2/4/6 subfamily transcripts predominated over other alpha-tubulin transcripts in Arabidopsis seedlings. The lefty double mutant seedlings showed helical growth in hypocotyls and radial cell expansion in the root elongation zone where mutant cortical microtubule arrays were more fragmented and less well aligned than wild-type arrays. Branching of leaf trichomes was highly reduced. In adult mutant plants, anisotropic growth of anther filament cells was severely impaired. These results suggest that left-handed twisted elongation is an intermediate state that leads to full isotropic expansion as the cortical microtubules are increasingly destabilized.

Arabidopsis↗
PubMed2004

Low concentrations of propyzamide and oryzalin alter microtubule dynamics in Arabidopsis epidermal cells.

Previous studies showed that sub-micromolar concentrations of the microtubule-targeting herbicide propyzamide cause a right-handed helical arrangement of cortical microtubule arrays and left-handed twisting in elongating Arabidopsis epidermal cells. When seedlings were grown in the presence of 1-2 microM propyzamide or 50-100 nM oryzalin, we show that microtubules spent more time in a paused state in which they exhibited little net change in length. The drug treatment also resulted in slower growth and shortening velocities, increased catastrophe, and an overall decrease in microtubule turnover. A reduction in microtubule dynamic turnover may underlie the drug-induced rearrangement of cortical arrays.

Arabidopsis↗
PubMed2004

Ahnak/Desmoyokin is dispensable for proliferation, differentiation, and maintenance of integrity in mouse epidermis.

Desmoyokin was first isolated from bovine muzzle epidermis and thought to be an epidermal desmosome-related protein. We previously demonstrated that the Desmoyokin gene is identical to the Ahnak gene, which is expressed ubiquitously and downregulated in neuroblastomas. It was assumed Ahnak/Desmoyokin was associated with epidermal cell adhesion, tumorigenesis, cell proliferation and differentiation, and embryonic development. To determine the precise biological function of Ahnak/Desmoyokin, we generated a null mutation in ES cells and mice. The resultant Ahnak/Desmoyokin-deficient ES cells normally differentiated into embryoid bodies and neural cells. The mutant mice were viable and fertile and showed no gross developmental defects. Electron microscopic examination of skin sections demonstrated that the ultrastructure of epidermal intercellular junctions, including desmosomes, of the mutant mice was indistinguishable from that of wild-type mice. Two-stage chemical skin carcinogenesis experiments showed no difference in frequency or onset of cutaneous tumor formation between wild-type and mutant mice. Moreover, no tumorigenesis was observed in other tissues and organs of mutant mice up to 2 y of age. These results lead us to conclude that Ahnak/Desmoyokin deficiency has only a minimal effect on epidermal cell adhesion, tumorigenesis, cell proliferation and differentiation, and overall mouse development.

Animals↗
PubMed2004

A case of anti-epiligrin cicatricial pemphigoid associated with lung carcinoma and severe laryngeal stenosis: review of Japanese cases and evaluation of risk for internal malignancy.

A 68-year-old Japanese male with a five-year-history of lung carcinoma showed recurrent blisters and erosions on the oral and genital mucosae and the skin. The patient complained of dyspnea due to severe laryngeal stenosis and underwent a tracheostomy. A skin biopsy specimen showed a subepidermal blister and linear deposits of IgG and C3 at the basement membrane zone of the epidermis. Indirect immunofluorescence examination demonstrated circulating IgG anti-basement membrane zone autoantibodies that reacted to epiligrin on immunoblotting. Based on a diagnosis of anti-epiligrin cicatricial pemphigoid, he was treated with prednisolone, minocycline hydrochloride and nicotinamide. Although no new skin lesions appeared, he died of lung carcinoma five months after the tracheostomy. A review of reported cases with anti-epiligrin cicatricial pemphigoid in Japan disclosed that 5 of 16 cases (31.2%) were complicated by internal malignancies.

Aged↗
PubMed2004

A case of refractory bullous pemphigoid with plasmapheresis-associated thrombopenia: efficacy of pulsed intravenous cyclophosphamide therapy.

We present a 69-year-old woman with refractory bullous pemphigoid successfully treated with pulsed intravenous cyclophosphamide therapy. Because various other early treatments including 4,4'-diaminodiphenylsulphone (DDS), minocycline/nicotinamide, cyclosporin, azathioprine, high-dose oral prednisolone, and methylprednisolone pulse therapy were either ineffective or intolerable, she was treated with double filtration plasmapheresis, but she responded poorly with the rare complication of severe transient thrombopenia. Finally, she gradually recovered with pulsed intravenous cyclophosphamide therapy.

Aged↗
PubMed2004

A case of antiepiligrin cicatricial pemphigoid with nephrotic syndrome.

We report a 71-year-old woman with antiepiligrin cicatricial pemphigoid associated with nephrotic syndrome. She presented with a six-month history of pruritic blisters over her trunk and legs. She also had episodes of recurrent painful oral erosions. A skin biopsy showed a subepidermal bulla, and a direct immunofluorescence (DIF) study revealed linear deposition of IgG and C3 at the basement membrane zone (BMZ). Indirect immunofluorescence (IIF) staining of 1 M NaCl-split skin demonstrated circulating IgG autoantibodies reactive with the dermal side. Immunoprecipitation studies of the patient's serum disclosed IgG autoantibodies directed against a set of polypeptides that corresponded to laminin 5 (beta 3 gamma 2). Based upon the long-standing edema of her legs and her hypoproteinemia, she was diagnosed with nephrotic syndrome. To our knowledge, the association of antiepiligrin cicatricial pemphigoid with nephrotic syndrome has not been reported previously.

Aged↗
PubMed2004

Evaluation of esophageal varices using contrast-enhanced coded harmonic ultrasonography.

AIM: To investigate if esophageal varices can be evaluated using external contrast-enhanced ultrasonography with Levovist and coded harmonic angio (CHA). METHODS: Subjects were six healthy adult volunteers and 23 patients with liver cirrhosis. After identification of the lower esophagus under B-mode scanning, 300 mg/mL of Levovist was intravenously injected into the cubital vein at a rate of 1 mL/s under observation by CHA-mode scanning. Approximately 30 s after intravenous administration, interval-delay scanning was performed every second to visualize the area around the lower esophageal lumen. The degree of ultrasonographic enhancement was assessed as either no enhancement (negative); linear enhancement along the esophageal wall (weak) or full enhancement of the esophageal lumen (strong). Endoscopic evaluation of esophageal varices was also performed. RESULTS: The CHA enhancement around the lower esophageal lumen was identified in 21 of the 23 patients. Of these 21 patients, endoscopic assessments of varices were as follows: F0 in four patients, F1 in seven patients, F2 in three patients, and F3 in seven patients. Nine patients were red color sign (RCS)-positive. Regarding the relationship between ultrasonographic enhancement and endoscopic assessment, enhancement was identified as negative in all four F0 patients, negative in three and weak in three and strong in one of the seven F1 patients, weak in one and strong in two of the three F2 patients, and weak in two and strong in five of the seven F3 patients, respectively. Furthermore, of the nine RCS-positive patients, enhancement was recognized as strong in seven and weak in two patients. Ultrasonographic enhancement was identified as negative in all six healthy volunteers. CONCLUSIONS: By performing contrast-enhanced CHA ultrasonography using Levovist, ultrasonographic enhancement was detectable in all patients with varices categorized as F2 or above. Because the present method is easy to perform and causes less pain to patients compared to endoscopy, it is useful for following and assessing esophageal varices in patients with liver cirrhosis.

Aged↗