Biomedical subjects

T Itoh

Publications and source records attributed to T Itoh.

At least 217 records · Page 12Linked to original sources

PubMed2000

Xeroderma pigmentosum variant heterozygotes show reduced levels of recovery of replicative DNA synthesis in the presence of caffeine after ultraviolet irradiation.

Patients with xeroderma pigmentosum variant show clinical photosensitivity, skin neoplasias induced by ultraviolet light, and defective postreplication repair, but normal nucleotide excision repair. We recently reported an alternative, simple method for the diagnosis of xeroderma pigmentosum variant that measures by autoradiography three cellular markers for DNA repair after ultraviolet irradiation: unscheduled DNA synthesis, recovery of RNA synthesis, and recovery of replicative DNA synthesis. Among hereditary photosensitive disorders, including other xeroderma pigmentosum groups, Cockayne syndrome, and a newly established ultraviolet-sensitive syndrome, only xeroderma pigmentosum variant cells exhibited normal unscheduled DNA synthesis, normal recovery of RNA synthesis, but reduced recovery of replicative DNA synthesis (51 +/- 6% the rate relative to normal controls). This reduction of recovery of replicative DNA synthesis was enhanced in the presence of a nontoxic level of caffeine to 36 +/- 5%. In this study we assess the cellular markers in two independent families that included two photosensitive patients that were identified as xeroderma pigmentosum variant. Cells from heterozygotic parents showed normal levels of unscheduled DNA synthesis, recovery of RNA synthesis, and recovery of replicative DNA synthesis, but reduced rates of recovery of replicative DNA synthesis in the presence of 1 mM caffeine (53 +/- 8% relative to the normal control). Furthermore, with a colony-forming assay, the cells showed normal survival by ultraviolet without caffeine, but slightly reduced survival by ultraviolet with 1 mM caffeine present. In one family, we confirmed inheritance of two heterozygous mis-sense mutations. One mutation is an A-->G transition at nucleotide 1840 that generates a K535E mis-sense mutation. Another mutation is an A-->C transversion at nucleotide 2003 that generates a K589 mis-sense mutation. Each of these mutations were absent in 52 unrelated Japanese individuals. These results suggest that xeroderma pigmentosum variant heterozygotes can be identified by their sensitivity to ultraviolet irradiation in the presence of nontoxic levels of caffeine.

Adult↗

PubMed2000

UVs syndrome: establishment and characterization of fibroblastic cell lines transformed with simian virus 40 DNA.

Ultraviolet-sensitive syndrome (UVsS) is a newly established photosensitive disorder. Patients with UVsS showed mild clinical manifestations similar to classical types of xeroderma pigmentosum, and had biochemical phenotypes of Cockayne syndrome but not those of xeroderma pigmentosum. Fibroblasts from a UVsS patient were treated with simian virus 40 DNA containing the large T antigen with a defective origin of DNA replication to establish a transformed cell line. We obtained two independent transformed cell lines (Kps3SVY and Kps3SVI3) and report their initial characterization. These cells showed the same pattern in variable number of tandem repeat analyses as a primary fibroblast cell strain, Kps3, and retain the UVsS phenotype as demonstrated by increased UV sensitivity (three to four times more sensitive to UV than normal cells) and by reduced recovery of RNA synthesis after UV irradiation (20% - 30% of that of normal cells). These cells, however, showed different phenotypes as regards plating efficiency, doubling time, and transfection efficiency in spite of the fact that the same method was used to transform the cells. Kps3SVY cells were closer in phenotype to Kps3 cells than Kps3SVI3 cells. As a variable number of tandem repeat analyses also showed that Kps3SVI3 cells have lost one of the two alleles in some chromosomes, this may explain the different phenotypes between Kps3SVY and Kps3SVI3 cells. Moreover, these cells were distinct from cells with Cockayne syndrome group A or B. Thus, these cell lines provide the opportunity to conduct transfection studies on cells with the UVsS defect in DNA repair and transcription.

Cell Line, Transformed↗

PubMed2000

Reinvestigation of the classification of five cell strains of xeroderma pigmentosum group E with reclassification of three of them.

Xeroderma pigmentosum is a photosensitive syndrome caused by a defect in nucleotide excision repair or postreplication repair. Individuals of xeroderma pigmentosum group E (xeroderma pigmentosum E) have a mild clinical form of the disease and their cells exhibit a high level of nucleotide excision repair as measured by unscheduled DNA synthesis, as well as biochemical heterogeneity. Cell strains from one group of xeroderma pigmentosum E patients have normal damage-specific DNA binding activity (Ddb+), whereas others do not (Ddb-). Using a refinement of a previously reported cell fusion complementation assay, the previously assigned Ddb+ xeroderma pigmentosum E strains, XP89TO, XP43TO, and XP24KO, with various phenotypes in DNA repair markers, were reassigned to xeroderma pigmentosum group F, xeroderma pigmentosum variant, and ultraviolet-sensitive syndrome, respectively. The Ddb- xeroderma pigmentosum E strains, XP82TO, and GM02415B, which showed almost normal cellular phenotypes in DNA repair markers, however, remained assigned to xeroderma pigmentosum group E. With the exception of the Ddb+ strain XP89TO, which demonstrated defective nucleotide excision repair, both Ddb- and Ddb+ xeroderma pigmentosum E cells exhibited the same levels of variation in unscheduled DNA synthesis that were seen in normal control cells. By genome DNA sequencing, the two Ddb- xeroderma pigmentosum E strains were shown to have mutations in the DDB2 gene, confirming previous reports for XP82TO and GM02415B, and validating the classification of both cells. As only the Ddb- strains investigated remain classified in the xeroderma pigmentosum E complementation group, it is feasible that only Ddb- cells are xeroderma pigmentosum E and that mutations in the DDB2 gene are solely responsible for the xeroderma pigmentosum E group.

DNA↗

PubMed2000

Low power laser protects human erythrocytes In an In vitro model of artificial heart-lung machines.

The protective effect of the low power helium-neon (He-Ne) laser against the damage of human erythrocytes in whole blood was examined in a perfusion model using an artificial heart-lung machine. Preserved human whole blood was diluted and perfused in 2 closed circuits with a double roller pump. The laser irradiated one of the circuits (laser group), and none the other (control group). In the laser group, erythrocyte deformability and erythrocyte adenosine triphosphate (ATP) levels were significantly higher, and free hemoglobin levels were significantly lower than those in the control group. Subsequent morphological findings by means of scanning electron microscope were consistent with these results. Low power He-Ne laser protected human erythrocytes in the preserved diluted whole blood from the damage caused by experimental artificial heart-lung machines. The clinical application of low power laser treatment for extracorporeal circulation is suggested.

Adenosine Triphosphate↗

PubMed2000

Eosinophilic apoptosis in sinus mucosa: relationship to tissue eosinophilia and its resolution in allergic sinusitis.

BACKGROUND: Apoptosis, which is regulated by both cell survival and death signals, is important for the swift clearance of unwanted cells. OBJECTIVE: We sought to elucidate whether eosinophilic apoptosis is associated with tissue eosinophilia and to determine its resolution in allergic sinusitis (AS). METHODS: Numbers of eosinophils, numbers of IL-5(+) cells, and the apoptosis index of eosinophils were calculated in the submucosa (both superficial and deep layers) of patients with AS by using histochemical methods before and after prednisolone treatment. Patients without AS were used for control groups. Anti-EG2 antibody was used to identify eosinophils. IL-5, Fas, or Bax expression of eosinophils was evaluated to elucidate the role of the factors affecting eosinophilic apoptosis. RESULTS: EG2 and IL-5(+) cells were abundant in the submucosa of patients with AS, especially in the superficial layer. About 50% to 60% of the IL-5-producing cells were eosinophils. Apoptotic eosinophils were less numerous in the superficial layer than the deep layer in these diseases. After prednisolone treatment, an induction of eosinophilic apoptosis was accompanied by a significant decrease in the number of EG2(+) and IL-5(+) cells. No remarkable difference was observed in the Fas or Bax expression of eosinophils after prednisolone treatment. CONCLUSION: Autocrine secretion of IL-5 from eosinophils may be one reason why eosinophilic disease is difficult to manage. Induction of eosinophilic apoptosis is critical for reversing tissue eosinophilia in patients with AS.

Adaptor Proteins, Signal Transducing↗

PubMed2000

Thioredoxin inhibits tumor necrosis factor- or interleukin-1-induced NF-kappaB activation at a level upstream of NF-kappaB-inducing kinase.

Gene induction by tumor necrosis factor-alpha (TNFalpha) or interleukin-1beta (IL-1beta) is mediated in part by activation of the transcription factor nuclear factor kappaB (NF-kappaB), and requires signal adaptor molecules such as TNF receptor-associated factor (TRAFs). The latter interact with the NF-kappaB-inducing kinase (NIK), which is believed to be part of the IkappaB kinase complex. Although the precise mechanism is to be elucidated, it is well-known that antioxidant treatments inhibit the inflammatory cytokine-induced NF-kappaB activation. Thioredoxin (TRX) is a 12-kDa endogenous protein that regulates various cellular functions by modulating the redox state of proteins, overexpression of this molecule inhibits NF-kappaB activation. To elucidate the roles of TRX in the signal transduction of the cytokines, we investigated the effects of TRX on NF-kappaB activation induced by cytokine treatment or by overexpression of the signaling molecules. Our data show that TRX treatment inhibits NF-kappaB-dependent transcription at the level of downstream of TRAFs and upstream of NIK: TRX inhibited TRAF2-, TRAF5-, and TRAF6-induced NF-kappaB activation but does not inhibit NIK-, IKKalpha-, and MEKK-induced activation. In addition, we show that TRX inhibits NF-kappaB activation in a manner different from that for SAPK (stress activated protein kinase) inhibition.

Acetylcysteine↗

PubMed2000

Characterization of cross-links between cellulose microfibrils, and their occurrence during elongation growth in pea epicotyl.

The occurrence and chemical nature of the cross-links between cellulose microfibrils in outer epidermal cell walls in Pisum sativum cv. Alaska was investigated by rapid-freezing and deep-etching techniques coupled with chemical and enzymatic treatments. The cell wall in the elongating region of epidermal cells was characterized by the absence of the cross-links, while in the elongated region, the cell wall was characterized by the presence of cross-links. The cross-links remained in the cell wall of the elongated region after treatment with SDS electrophoresis sample buffer and treatment with 4% potassium hydroxide. After treatment with endo-1,4-beta-glucanase, which fragments xyloglucan, the cross-links were remarkably reduced from the cell wall of the elongated region. The endoglucanase treatment also reduced immunogold labeling of xyloglucan in the cell wall. The endoglucanase hydrolysate from the cell wall fraction of the elongated region gave spots of oligosaccharides in thin layer chromatography, which were identical to the spots of xyloglucan oligosaccharides produced by xyloglucanase from both the cell wall fraction and tamarind xyloglucan. These results indicate that the cross-links are made of xyloglucan. We discussed the possibility of cross-links involved in the control of mechanical properties of the cell wall.

Cell Wall↗

PubMed2000

Highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans show a distinct localization pattern in the tissues of Zea mays L.

Polyclonal antibodies which recognized highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans and did not cross-react with each other, were raised in order to examine localization of these epitopes in internodes of maize. Immunofluorescent labeling revealed different pattern between two succeeding developmental stages. The hsGAX epitope was localized evenly in primary walls in all tissue types, and strongly in unlignified secondary walls in phloem. However, lignified secondary walls in protoxylem, parenchyma and a part of fibers were faintly labeled with this epitope. Moreover, the epitope showed limited binding in lignified parenchyma and fiber walls at ultrastructural level. Low-branched xylan epitope was localized evenly throughout lignified walls in all tissue types. This epitope was also localized only in lignified walls of other organs such as leaf, root apex and dark-grown mesocotyl. Low-branched xylans are significantly related to lignification. Localization of hsGAX epitope in their organs was similar to that in internodes. The hsGAX epitope was distributed both in unlignified walls of all tissues and in lignified walls of parenchyma and annular thickening of protoxylem. We propose that hsGAX has separate functions in lignified and unlignified tissues. In conclusion, at tissue level, hsGAX is localized mainly in unlignified walls, and low-branched xylans in lignified walls.

Antibody Specificity↗

PubMed2000

Intraperitoneal injection of dextran sulfate as an anti-adherent drug for the prevention of peritoneal metastasis of cancer shows low toxicity in animals.

Intraperitoneal dextran sulfate with a mean molecular weight of 5 x 10(5) has been developed for use in an anti-adherent therapy against peritoneal carcinomatosis. The present study examined acute toxicity of i.p. injection of dextran sulfate in mice and rabbits. The 10, 50 and 90% lethal dose values are 0.213 (0.146-0.252), 0.336 (0.291-0.405) and 0.530 mg/g (0.431-0.873 mg/g: 95% confidence interval) in mice, respectively. These are markedly larger than the efficacious dose of 0.005-0.01 mg/g obtained previously. Death or symptoms of intoxication were seen within 3 days after administration of toxic doses. Rabbits received i.p. injection of dextran sulfate at 0.02 mg/g, which was close to the efficacious dose. At 2, 4, 6, 8 and 13 days after administration, blood was taken for biochemical and hematological analyses. Dextran sulfate at 0.02 mg/g induced no remarkable abnormal findings. These results suggest that the i.p. dextran sulfate is safe as an anti-adherent agent against peritoneal metastasis of cancer.

Animals↗

PubMed2000

Increased activity in benign phyllodes tumor on Tc-99m MDP scintimammography.

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Adult↗

PubMed2000

Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney.

A novel barophilic, hyperthermophilic archaeon was isolated from a deep-sea hydrothermal vent chimney at the Myojin Knoll in the Ogasawara-Bonin Arc, Japan. The cells were found to be irregular cocci and motile with multiple polar flagella. Growth was observed between 60 and 88 degrees C (opt. 83 degrees C; 30 min doubling time), pH 4.0 and 8.0 (opt. pH 6.0), 20 and 73 g sea salts l-1 (opt. 47 g l-1) and 0.1 and 60 MPa (opt. 30 MPa). The isolate was a strictly anaerobic chemoorganotroph capable of utilizing proteinaceous substrates such as yeast extract, peptone, tryptone and casein in the presence of elemental sulfur or ferrous iron. The G + C content of the genomic DNA was 53.5 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that the isolate was a member of an ancient lineage of the Thermococcales that diverged prior to the formation of the two genera Thermococcus and Pyrococcus. On the basis of the physiological and molecular properties of the new isolate, the name Palaeococcus ferrophilus gen. nov., sp. nov. is proposed. The type strain is strain DMJT (= JCM 10417) [corrected].

Anti-Bacterial Agents↗

PubMed2000

Natrinema versiforme sp. nov., an extremely halophilic archaeon from Aibi salt lake, Xinjiang, China.

A novel extremely halophilic archaeon, strain XF10T, was isolated from a salt lake in China. This organism was neutrophilic, non-motile and pleomorphic, and was rod, coccus or irregularly shaped. It required at least 1.5 M NaCl for growth and grew in a wide range of MgCl2 concentrations (0.005-0.5 M). Lipid extract of whole cells contained two glycolipids with the same chromatographic properties as two unidentified glycolipids found in the two described Natrinema species, Natrinema pellirubrum and Natrinema pallidum. Phylogenetic analysis based on 16S rDNA sequence comparison revealed that strain XF10T clustered with the two described Natrinema species and several other strains (strains T5.7, GSL-11 and Haloterrigena turkmenica JCM 9743) with more than 98.1% sequence similarities, suggesting that strain XF1OT belongs to the genus Natrinema. Comparative analysis of phenotypic properties and DNA-DNA hybridization between strain XF10T and the Natrinema species supported the conclusion that strain XF10T is a novel species within the genus Natrinema. The name Natrinema versiforme sp. nov. is proposed for this strain. The type strain is XF10T (=JCM 10478T=AS 1.2365T=ANMR 0149T).

Base Composition↗

PubMed2000

Null mutation of PCLN-1/Claudin-16 results in bovine chronic interstitial nephritis.

Inherited chronic renal diseases are associated with failures in glomerular filtration and tubular resorption. Such failures invariably result from defects in selective filtration and absorption in surface renal epithelium. Recently, we described an autosomal recessive chronic interstitial nephritis with diffuse zonal fibrosis (CINF) in cattle. Bovine CINF, characterized by increased blood urea nitrogen, creatinine, and urinary proteins, leads to lethality before puberty, usually within the first 6 months or year of life. Here, we demonstrate that the first four exons of PCLN-1/Claudin-16 (CL-16), which encodes a member of the claudin family of tight junction proteins, were deleted in CINF-affected cattle. CL-16 was expressed preferentially in kidneys of normal cattle, but transcripts were totally absent in affected offspring. This observation suggests that the lack of CL-16 protein contributes to the dysfunction of paracellular renal transport systems.

Amino Acid Sequence↗

PubMed2000

Effects of paternal lymphocyte immunization on peripheral Th1/Th2 balance and TCR V beta and V gamma repertoire usage of patients with recurrent spontaneous abortions.

PROBLEM: The mechanism of immunotherapy for patients with recurrent spontaneous abortions is not well understood. In order to investigate the suppressor mechanism of paternal lymphocyte immunization, we examined peripheral blood lymphocyte subpopulations and the repertoire of T-cell receptor (TCR) gene segments. METHOD OF STUDY: Twelve patients with recurrent miscarriage were treated with immunization with paternal lymphocyte vaccinations three times during 12-14 weeks. Before and 2 weeks after the final inoculation, lymphocyte subsets and intra-cellular interferon (IFN)-gamma and/or interleukin (IL)-4 production were examined by flow cytometry. TCR V beta and V gamma repertoires were examined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: We found no significant difference in CD4/CD8 ratios, prevalence of CD56+CD3+ or CD57+CD3+ cells (possible extrathymic T cells), gamma(delta)T cells, and CD5+ CD19+ (B-1) cells. However, by in vitro activation with phorbol 12-myristate 13-acetate (PMA) and ionomycin, peripheral CD4 cells demonstrated a significant decrease of IFN-gamma-producing T helper 1 (Th1) cells and an increase of IL-4-producing T helper 2 (Th2) cells after immunotherapy. Seven of nine patients who exhibited remarkable decreases in Th1/Th2 ratios became pregnant within 6 months after three courses of immunotherapy, and four women delivered healthy babies, while none of the three patients who exhibited an increased or unchanged Th1/Th2 ratio had full-term pregnancies (chi2 < 0.0001). Further, changes in usage of TCR V beta and V gamma gene segments were observed after immunotherapy in six patients examined. CONCLUSION: Our findings suggest a shift of Th1-dominant to Th2-dominant status by vaccination might play important roles in maintaining successful pregnancies. Induction of some T cells that utilize different TCR repertoires possibly suppresses maternal rejection reactions.

Abortion, Habitual↗

PubMed2000

Prophylactic effect of FK463, a novel antifungal lipopeptide, against Pneumocystis carinii infection in mice.

The prophylactic effect of FK463, a new water-soluble echinocandin-like lipopeptide with inhibitory activity against 1, 3-beta-D-glucan synthase, against Pneumocystis carinii infection was investigated with the severe combined immunodeficient (SCID) mouse model. Treatment with FK463, pentamidine, and saline only was performed for 6 weeks from the day after the SCID mice were inoculated intranasally with infected lung homogenates. FK463 at 0.2 or 1.0 mg/kg of body weight, pentamidine at 4 mg/kg, or saline was subcutaneously administered daily into the backs of the SCID mice. The effects of the drugs were evaluated by detection of P. carinii cysts in mouse lung homogenates by toluidine blue O staining, lung histology, and PCR amplification of a P. carinii-specific DNA fragment from the lungs. P. carinii cysts were detected in the lungs of all mice administered saline. In contrast, no cysts were detected in mice administered both doses of FK463 and pentamidine. A specific DNA fragment was amplified from all mice administered saline and at least half or more of the mice administered FK463 and pentamidine. These results indicate that FK463 acts on cyst wall formation but not on trophozoite proliferation and is extremely effective in preventing P. carinii-associated pneumonia. These results suggest that FK463 is potentially useful as a prophylactic agent against P. carinii infection.

Animals↗

PubMed2000

Five cases of MRSA-infected patients with cerebrovascular disorder and in a bedridden condition, for whom bu-zhong-yi-qi-tang (hochu-ekki-to) was useful.

The herbal formula bu-zhong-yi-qi-tang (hochu-ekki-to, 5 grams per day) was administered to five MRSA-infected bedridden patients with cerebrovascular disorder, dementia and, in two cases, bed sores, who had resistance to several antibacterial drugs. After hochu-ekki-to the patients showed an excellent result; disappearance of MRSA, improvement of their general condition, and no side effects. Therefore, it is thought that hochu-ekki-to may be a useful drug for MRSA-infected patients.

Cerebrovascular Disorders↗

PubMed2000

Effect of acute hypoxia on vasopressin release and intravascular fluid during dynamic exercise in humans.

To test the hypothesis that acute hypoxia does not modify the relationship between plasma vasopressin concentration ([AVP](p)) and plasma osmolality (P(osmol)) during exercise and that the increase in [AVP](p) during exercise is due mainly to the exercise intensity-dependent increase in P(osmol), we examined [AVP](p) during a graded exercise in a hypoxic condition (13% O(2), N(2) balance) in seven healthy male subjects. A graded exercise in a normoxic condition on a separate day served as the control. Hypoxia reduced peak aerobic power (VO(2 peak)) by 32.4 +/- 2.7%. Blood samples obtained during rest and at around 25, 45, 65, 80, and 100% of VO(2 peak) of each of the respective conditions were used for analyses of intravascular water and electrolyte balance. The pattern of the changes in fluid and electrolyte balance in response to percent VO(2 peak) was similar between the two conditions. Plasma volume decreased linearly as percent VO(2 peak) increased while P(osmol) increased in a curvilinear fashion with a steep increase occurring at above approximately 66% VO(2 peak). Above this relative exercise intensity, plasma sodium, potassium, and lactate concentrations also increased, whereas plasma bicarbonate concentration decreased. Thus transvascular fluid movement at above approximately 66% VO(2 peak) was due to the net efflux of hypotonic fluid out of the vascular space in both conditions. The relationship between [AVP](p) and P(osmol) during exercise in response to relative exercise intensity was similar between the two conditions. The results indicate that acute mild hypoxia itself has no direct effect on vasopressin release, and it does not modify the relationship between [AVP](p) and P(osmol) during exercise. The results also support the hypothesis that exercise-induced vasopressin release is primarily stimulated by increased P(osmol) produced by hypotonic fluid movement out of the vascular space in a relative exercise intensity-dependent manner.

Acute Disease↗

PubMed2000

RT-PCR suggests human skeletal muscle origin of alveolar soft-part sarcoma.

In 1952, Christopherson et al. proposed that alveolar soft-part sarcoma (ASPS) was a distinct entity with unique clinical and pathological features. Since their report, its histogenesis has not been determined. In order to clarify the histogenesis of ASPS, a study using reverse transcription polymerase chain reaction using cDNAs from MyoD1 and myogenin, and the actin filament from human-skeletal-muscle-related mRNAs has been performed in 5 cases of ASPS. The expression of MyoD1 and myogenin was determined in 5 and 2 cases of the 5 cases, respectively. Moreover, expression of the many mRNAs from the actin filament of skeletal muscle was also found in ASPS. According to these findings, it is now postulated that ASPS is of skeletal muscle origin.

Actins↗