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Biomedical subjects

H Saitoh

Publications and source records attributed to H Saitoh.

At least 37 records · Page 2Linked to original sources
PubMed2002

Dual cellulose-digesting system of the wood-feeding termite, Coptotermes formosanus Shiraki.

The distribution of endo-beta-1,4-glucanase (EG) components in the digestive system of the wood-feeding termite, Coptotermes formosanus Shiraki, was investigated by zymogram analysis using polyacrylamide gel electrophoresis, followed by N-terminal protein sequencing. EG components similar to glycoside hydrolase family (GHF) 9 members were restricted to the salivary glands, the foregut, and the midgut, whereas components similar to GHF7 members were confined to the hindgut where numerous cellulolytic flagellates were harbored. RT-PCR experiments revealed that five GHF9 EG mRNAs (1348 bp) homologous to other termite EGs were expressed in the salivary glands and the midgut. The crude extract prepared from the midgut as well as that from the hindgut produced glucose from crystalline cellulose. These data suggest that C. formosanus has two independent cellulose-digesting systems: one in the midgut where cellulose digestion is accomplished by endogenous cellulases and the other in the hindgut which makes use of other cellulases possibly from symbiotic flagellates.

Acrylic Resins↗
PubMed2002

Distinct TCRAV and TCRBV repertoire and CDR3 sequence of T lymphocytes clonally expanded in blood and GVHD lesions after human allogeneic bone marrow transplantation.

Acute graft-versus-host disease (GVHD) is a disorder involving the skin, gut and liver that is caused by mismatches of major and/or minor histocompatibility antigens between the HLA-identical donor and recipient. If T lymphocytes infiltrating GVHD lesions recognize antigens expressed in these organs, T cell clones should expand in inflammatory tissues. We previously reported that recipients of allogeneic bone marrow grafts have clonally expanded TCRalphabeta(+) T lymphocytes soon after transplantation, which leads to a skew of TCR repertoires. To establish whether or not the same antigens cause clonal expansion of T lymphocytes in both blood and GVHD tissues, we examined the usage of TCR alpha and beta chain variable regions (TCRAV and TCRBV) and determined the complementarity-determining region 3 (CDR3) of T lymphocytes clonally expanded in circulating blood and GVHD lesions. We found that the repertoires and CDR3 diversity of TCRAV and TCRBV differed between the GVHD lesions and circulating blood, suggesting the selective recruitment of antigen-specific T cells into GVHD tissues. We also found that the usage of TCRAV and TCRBV by the clonally expanded T lymphocytes and their CDR3 sequences differed between the GVHD tissues and blood. These results suggest that the antigen specificity of TCRalphabeta(+) T lymphocytes clonally expanded in blood and GVHD lesions is different.

Acute Disease↗
PubMed2002

Anabolic effects of recombinant human parathyroid hormone (1 - 84) and synthetic human parathyroid hormone (1 - 34) on the mandibles of osteopenic ovariectomized rats with maxillary molar extraction.

In rodent osteoporosis models such as ovariectomized (OVX) rats, intermittently administered human parathyroid hormone (hPTH) has an anabolic effect in vertebrae and long bones. In the present experiments, subcutaneously injected hPTH(1 - 34) or hPTH(1 - 84) dose- and time-dependently increased bone mineral density (BMD) as measured by dual energy X-ray absorptiometry in mandibles, L2 to L4 vertebrae and femurs of such rats. The highest dose (15.9 nmol/kg, s. c.) of either peptide given four times weekly for 10 weeks completely reversed the effects of overiectomy on BMD. Significant elevation in lumbar BMD after 10 weeks was observed with hPTH(1 - 34) or hPTH(1 - 84) at 1.1 nmol/kg, whereas hPTH(1 - 34) at 1.1 and 4.2 nmol/kg significantly increased BMD of the whole bone and the metaphysis of the femur and the diaphysis of the bone, respectively. In contrast, significant effects of hPTH(1 - 84) administration on BMD increase in the femur were observed at 4.2 and 15.9 nmol/kg in the whole bone and the metaphysis, and in the diaphysis, respectively. Maxillary molar extraction left mandibular BMD in rats with intact ovaries unchanged, but significantly decreased mandibular BMD in OVX rats. Administration of hPTH(1 - 84) for 10 weeks in OVX rats without or with extraction significantly increased BMD in the mandibular molar region at doses of 15.9 and 4.2 nmol/kg, respectively, indicating that efficacy was increased by extraction. A significant BMD increase in the molar region in OVX rats with extraction occurred at only 1.1 nmol/kg of hPTH(1 - 34) and 4.2 nmol/kg of hPTH(1 - 84). Also, BMD of the ramus region was increased by administration of both peptides to a lesser extent than that of the molar region in these rats. Thus, intermittent administration of hPTH, especially hPTH(1 - 34), has an anabolic effect on bone, particularly alveolar bone. Such treatment may increase alveolar bone mass in postmenopausal women with osteoporosis.

Absorptiometry, Photon↗
PubMed2001

A 28 kDa protein of the Bacillus thuringiensis serovar shandongiensis isolate 89-T-34-22 induces a human leukemic cell-specific cytotoxicity.

A 28 kDa protein that exhibits cytocidal activity specific for human leukemic T (MOLT-4) cells was purified from proteinase K-digested parasporal inclusion of a Bacillus thuringiensis serovar shandongiensis isolate. The N-terminal sequence of the protein was identical with that of the 32 kDa protein, regarded as a protoxin, of the inclusion proteins. The median effective concentration of this protein was 0.23 microg/ml against MOLT-4 cells and its specific activity was 7.9 times greater than that of the whole inclusion proteins. The 28 kDa protein induced necrosis-like cytotoxicity against MOLT-4 cells and the cytopathic effect with the passage of time was characterized by cell swelling, nuclear membrane isolation and chromatin condensation.

Antineoplastic Agents↗
PubMed2001

Signal transducer and activator of transcription (STAT)-induced STAT inhibitor 1 (SSI-1)/suppressor of cytokine signaling 1 (SOCS1) inhibits insulin signal transduction pathway through modulating insulin receptor substrate 1 (IRS-1) phosphorylation.

Signal transducer and activator of transcription (STAT)-induced STAT inhibitor 1 (SSI-1) is known to function as a negative feedback regulator of cytokine signaling, but it is unclear whether it is involved in other biological events. Here, we show that SSI-1 participates and plays an important role in the insulin signal transduction pathway. SSI-1-deficient mice showed a significantly low level of blood sugar. While the forced expression of SSI-1 reduced the phosphorylation level of insulin receptor substrate 1 (IRS-1), SSI-1 deficiency resulted in sustained phosphorylation of IRS-1 in response to insulin.Furthermore, SSI-1 achieves this inhibition both by binding directly to IRS-1 and by suppressing Janus kinases. These findings suggest that SSI-1 acts as a negative feedback factor also in the insulin signal transduction pathway through the suppression of IRS-1 phosphorylation.

Animals↗
PubMed2001

Immunohistochemical study of the kidneys after severe muscular injury.

Severe muscular injury sometimes causes renal failure, and myoglobin in skeletal muscle is known to induce toxic free oxygen radicals in the kidneys. The relationship between the immunohistochemical expression of myoglobin and the scavenger copper/zinc superoxide dismutase (Cu/Zn-SOD) was investigated in kidneys taken from two autopsy groups, a group with tourniquet shock (n = 4), and a group with severely injured skeletal muscle (n = 18). Paraffin-embedded kidney sections were used for immunohistochemical staining by the avidin-biotin-complex (ABC) method using antibodies against myoglobin and Cu/Zn-SOD. Detection of the two antigens was analyzed qualitatively. In most cases of tourniquet shock in which the survival time was considered to be relatively long, myoglobin staining was positive and Cu/Zn-SOD was negative. Among the seven cases of severely injured skeletal muscle in which the survival period was considered to be relatively short, positive staining was detected immunohistochemically for both myoglobin and Cu/Zn-SOD. Moreover, in most of the cases in this group that showed acute tubular necrosis, immunohistochemical staining was negative for both markers, whereas positive staining was found for most of the cases in which the kidneys were revealed to be normal by HE staining. These findings suggest that when myoglobin enters the kidneys via the circulation, Cu/Zn-SOD reacts to eliminate free radicals, but is depleted by consumption in the long run, and that there might be a relationship between these histological findings and immunohistochemical expression.

Adolescent↗
PubMed2001

A spontaneously ruptured gastric stromal tumor presenting as generalized peritonitis: report of a case.

Among the diverse clinical presentations of gastrointestinal stromal tumor (GIST), spontaneous rupture with peritonitis is extremely rare. We report herein the unusual case of a 75-year-old man found to have a spontaneously ruptured gastric stromal tumor after presenting with generalized peritonitis. The patient was brought to the emergency department of our hospital by ambulance, with generalized severe abdominal pain. On examination, his abdomen was extensively distended with generalized severe rebound tenderness. Abdominal computed tomography scan showed a giant mass arising from the anterior gastric wall with an irregular internal low-density area and a small amount of ascites. An emergency laparotomy revealed a ruptured gastric tumor with dissemination of its necrotic tissue throughout the peritoneal cavity. The tumor was excised together with normal gastric tissue around its base. The tumor, which was 15 x 11 x 4.4cm in size, had a coarse laceration over its well-capsulated smooth serosal surface with massive necrosis and clotted blood inside. Immunohistochemical examination revealed positive reactivity to C-kit protein, which was consistent with the newly introduced diagnostic criteria of GIST. The patient had an uneventful postoperative course and remains well.

Aged↗
PubMed2001

Effects of diets enriched in n-6 or n-3 fatty acids on cholesterol metabolism in older rats chronically fed a cholesterol-enriched diet.

Hypocholesterolemic effects in older animals after long-term feeding are unknown. Therefore, aged rats (24 wk of age) fed a conventional diet were shifted to diets containing 10% perilla oil [PEO; oleic acid + linoleic acid + alpha-linolenic acid; n-6/n-3, 0.3; polyunsaturated fatty acid/saturated fatty acid (P/S), 9.6], borage oil [oleic acid + linoleic acid + alpha-linolenic acid; n-6/n-3, 15.1; P/S, 5.3], evening primrose oil (EPO; linoleic acid + gamma-linolenic acid; P/S, 10.5), mixed oil (MIO; oleic acid + linoleic acid + gamma-linolenic acid + alpha-linolenic acid; n-6/n-3, 1.7; P/S, 6.7), or palm oil (PLO; palmitic acid + oleic acid + linoleic acid; n-6/n-3, 25.3; P/S, 0.2) with 0.5% cholesterol for 15 wk in this experiment. There were no significant differences in the food intake and body weight gain among the groups. The liver weight in the PEO (n-6/n-3, 0.3) group was significantly higher than those of other groups in aged rats. The serum total cholesterol and very low density lipoprotein (VLDL) + intermediate density lipoprotein (IDL) + low density lipoprotein (LDL)-cholesterol concentrations of the PLO (25.3) group were consistently higher than those in the other groups. The serum high density lipoprotein cholesterol concentrations of the PEO (0.3) and EPO groups were significantly lower than in the other groups at the end of the 15-wk feeding period. The liver cholesterol concentration of the PLO (25.3) group was significantly higher than those of other groups. There were no significant differences in the hepatic LDL receptor mRNA level among the groups. Hepatic apolipoprotein (apo) B mRNA levels were not affected by the experimental conditions. The fecal neutral steroid excretion of the PLO (25.3) group tended to be low compared to the other groups. The results of this study demonstrate that both n-6 fatty acid and n-3 fatty acids such as gamma-linolenic acid and alpha-linolenic acid inhibit the increase of serum total cholesterol and VLDL + IDL + LDL-cholesterol concentrations of aged rats in the presence of excess cholesterol in the diet compared with dietary saturated fatty acid.

Aging↗
PubMed2001

Significance of peristaltic squeezing of sperm bundles in the silkworm, Bombyx mori: elimination of irregular eupyrene sperm nuclei of the triploid.

Silkworm (Lepidoptera) males produce dimorphic sperm: nucleate eupyrene sperm and anucleate apyrene sperm. The eupyrene sperm are ordinary sperm to fertilise the eggs, while the function of apyrene sperm remains uncertain. After meiosis, 256 sperm cells are enclosed by a layer of cyst cells, forming a sperm bundle. We have previously documented that the nucleus of eupyrene sperm anchors to the head cyst cell, which locates at the anterior apex of the bundle, by an acrosome tubule-basal body assembly. Neither the basal body attachment to the nucleus nor the acrosome is seen in apyrene sperm, and the nuclei remain in the middle region of the bundle. Peristaltic squeezing starts from the anterior of the bundles in both types of sperm, and cytoplasmic debris of the eupyrene sperm, and both the nuclei and debris of apyrene sperm, are eliminated at the final stage of spermatogenesis. Since the irregularity of meiotic division in apyrene sperm is known, we used triploid silkworm males that show irregular meiotic division even in eupyrene spermatocytes and are highly sterile. The irregular nuclei of the triploid are discarded by the peristaltic squeezing just as those of the apyrene sperm. Transmission electron microscopic observations disclose the abnormality in the acrosome tubule and in the connection to the basal body. The peristaltic squeezing of sperm bundles in the silkworm appears to be the final control mechanism to eliminate irregular nuclei before they enter female reproductive organs.

Animals↗
PubMed2001

Phase II trial of paclitaxel by three-hour infusion for advanced gastric cancer with short premedication for prophylaxis against paclitaxel-associated hypersensitivity reactions.

PURPOSE: To determine the antitumor activity and toxicity of paclitaxel administered as a three-hour infusion and to estimate the incidence of hypersensitivity reactions using a short-course prophylaxis regimen in patients with advanced gastric cancer. PATIENTS AND METHODS: Sixty patients with advanced measurable gastric cancer and performance status 0 to 2, who had received at most one prior chemotherapy regimen, were treated with paclitaxel 210 mg/m2 over three hours following a short-course premedication with dexamethasone, diphenhydramine and ranitidine administered 30 min prior to the delivery of paclitaxel. Cycles were repeated every three weeks. Twenty-six patients (43%) had received prior chemotherapy for metastatic disease and six patients had received adjuvant chemotherapy. The response rate to prior chemotherapy was 50% (13 of 26). RESULTS: Objective responses were observed in 14 of 60 patients (23%; 95% confidence interval (95% CI): 13%-36%). Six of twenty-eight (21%) patients with no prior chemotherapy and 7 of 26 (27%) previously treated patients for metastatic disease developed a PR. There were no complete responses. The median duration of response was 152 days. The study treatment was well tolerated. Twenty-two of sixty patients (37%) experienced grade 3 or 4 neutropenia, which was the most common and serious toxicity. Grade 3 peripheral neuropathy occurred in one patient. Hypersensitivity reactions were observed in only nine patients (15%) and were all grade 1. CONCLUSIONS: A three-hour infusion of paclitaxel is both an active and safe treatment for gastric cancer using the short-course premedication schedule. Paclitaxel appears to be non-cross resistant to other active agents for gastric cancer.

Adult↗
PubMed2001

Chicken spindlin genes on W and Z chromosomes: transcriptional expression of both genes and dynamic behavior of spindlin in interphase and mitotic cells.

Contigs of genomic clones covering about 480 kb on the terminal region of the short arm of chicken W chromosome were obtained. By applying the exon trapping procedure on this whole region, a chicken homolog of spindlin gene, chSpin-W, was identified and subcloned. A counterpart gene, chSpin-Z, was found near the centromere on the long arm of Z chromosome. Although protein-coding regions of both genes are nearly identical, a part of the 3'-untranslated region is sufficiently different to distinguish the transcript of chSpin-W. Both chSpin-W and chSpin-Z are transcribed in early embryos. chSpin-Z is transcribed in various tissues of adult chickens, while chSpin-W is transcribed most prominently in ovarian granulosa and thecal cells. When female chicken embryonic fibroblasts were transfected with a cDNA construct for red fluorescent protein or green fluorescent protein-fused spindlin or FLAG-tagged spindlin, the expressed spindlin was co-localized with SUMO-1 in nuclear dots, ND10, in interphase cells, while the expressed spindlin was localized on entire chromosomes during mitosis. The localization of spindlin in ND10 reappeared after mitosis in daughter cell nuclei. A C-terminal region of spindlin was suggested to be required for the localization of spindlin to ND10.

Amino Acid Sequence↗
PubMed2001

Oligoclonal expansion of CD4(+)CD28(-) T lymphocytes in recipients of allogeneic hematopoietic cell grafts and identification of the same T cell clones within both CD4(+)CD28(+) and CD4(+)CD28(-) T cell subsets.

Recipients of allogeneic bone marrow grafts have clonally expanded CD8(+)CD28(-) T lymphocytes during the early period after transplantation, which leads to skewing of T cell receptor (TCR) repertoires. Here, we have addressed the question of whether clonal expansion of CD28(-) T cells is also observed in CD4(+) T lymphocytes after human allogeneic hematopoietic cell transplantation. We found that the fraction of T cells lacking CD28 expression in the CD4(+) subset was increased after transplantation, and expanded CD4(+)CD28(-) T lymphocytes carrying certain TCRBV subfamilies showed limited TCR diversity. In order to further study the ontogeny of CD4(+)CD28(-) T cells, we analyzed the complementarity-determining region 3 (CDR3) of the TCR-beta chain of CD4(+)CD28(+) and CD4(+)CD28(-) cells. We identified the same T cell clones within both CD4(+)CD28(-) and CD4(+)CD28(+) T cell subsets. These results suggest that both subsets are phenotypic variants of the same T cell lineage.

Amino Acid Sequence↗
PubMed2001

Primary retroperitoneal ganglioneuroblastoma in an adult.

A case of retroperitoneal ganglioneuroblastoma in a 60-year-old man is reported. This retroperitoneal tumor was surgically removed and pathologic diagnosis was ganglioneuroblastoma. Ganglioneuroblastoma usually occurs in children and is extremely rare in adults. The characteristics are described of an unusual tumor based on the published reports.

Ganglioneuroblastoma↗
PubMed2001

Need for sling surgery in patients with large cystoceles and masked stress urinary incontinence.

BACKGROUND: We studied the need for sling surgery in patients who suffered from large cystoceles and masked stress urinary incontinence. METHODS: Twenty patients who had large cystoceles but neither evidence nor history of stress incontinence were enrolled in this study. The cystocele was reduced using a reducing device. Masked urinary incontinence was identified by a 60 m pad weighing test and a stress test. The cystocele was reduced using a pessary ring in 14 patients, or a vaginal pack formed of two rolls of ordinary 28 x 28 cm gauze in six patients. Ten of 20 patients were diagnosed with masked stress urinary incontinence and were treated with anterior colporrhaphy and a suburethral sling procedure. The other 10 patients were continent after use of a cystocele reducing device and were treated with anterior colporrhaphy alone. Average follow-up periods of the patients with or without masked stress urinary incontinence were 51.2 months (range, 24.0-72.0 months) or 57.6 months (range, 27.0-70.0 months), respectively. RESULTS: One of the 10 patients diagnosed with masked stress incontinence had mild stress urinary incontinence postoperatively. None of the 10 continent patients had stress incontinence after anterior colporrhaphy alone. CONCLUSIONS: Reducing devices of protruding cystocele were clinically useful in the detection of masked stress incontinence. Sling surgery was effective to prevent emerging stress urinary incontinence for patients who suffered from cystocele and masked stress incontinence.

Aged↗
PubMed2001

Polytetrafluoroethylene patch sling for type 2 or type 3 stress urinary incontinence.

BACKGROUND: Surgical success rates and complications of anti-incontinence surgery were evaluated according to the type of stress incontinence and the type of surgery. METHODS: From 1989 to 1998, we treated 137 women for stress urinary incontinence with anti-incontinence surgery. Of the 137 patients, 110 had type 2 stress urinary incontinence and 27 had type 3 stress urinary incontinence. Of 110 patients with type 2 stress urinary incontinence, 57 underwent pubovaginal sling procedure and 53 were treated with the Gittes procedure. All of the patients with type 3 stress urinary incontinence underwent the pubovaginal sling procedure. RESULTS: Cure rates with the pubovaginal sling procedure were 82% in type 2 incontinence and 70% in type 3 incontinence. Cure rates with the Gittes procedure were 56%. The occurrence of de novo urge symptom and pelvic pain was low and bore no relation to either operative method or type of stress incontinence. CONCLUSIONS: The pubovaginal sling procedure using the polytetrafluoroethylene patch was effective for type 2 or 3 stress urinary incontinence.

Female↗
PubMed2001

Production of antimicrobial defensin in Nicotiana benthamiana with a potato virus X vector.

A recombinant plasmid, pTXS.TH, was constructed to express the gene-encoding wasabi (Wasabia japonica) defensin with the potato virus X (PVX) vector. pTXS.TH allows the expression of defensin in the host Nicotiana benthamiana, and the defensin protein WT1 can be purified from virus-infected leaves by heat treatment and affinity chromatography. WT1 exhibits strong antifungal activity toward the phytopathogenic fungi Magnaporthe grisea (50% inhibitory concentration [IC50] = 5 microg/ml) and Botrytis cinerea (IC50 = 20 microg/ml) but is weakly active against the phytopathogenic bacterium Pseudomonas cichorii. This virus-mediated expression system is a rapid and efficient method to produce and characterize antimicrobial proteins in plants. It is particularly useful for the study of proteins that are difficult to produce with other expression systems.

Anti-Infective Agents↗
PubMed2001

Secretion and gene expression of secretory leukocyte protease inhibitor by human airway submucosal glands.

Submucosal glands were isolated within 4 h of death from tracheae and bronchi obtained from autopsied lungs, and the secretory response of secretory leukocyte protease inhibitor (SLPI) was examined with ELISA and a secretory index. Although human neutrophil elastase (HNE) at low concentrations increased SLPI secretion above the control level (i.e., 149% of control level at 10(-11) M), HNE at high concentrations significantly decreased it below the control level (i.e., 16% of control level at 10(-7) M). The decrease in SLPI concentration was shown to result from the degradation of SLPI by excessive HNE. Methacholine induced significant secretion (i.e., 363% of control level at 10(-5) M) that was abolished by both M(1) and M(3) receptor antagonists. A semiquantitative analysis of SLPI mRNA by RT-PCR and Southern blot showed that compared with the superficial epithelium, submucosal glands had a 30-fold or higher level of SLPI mRNA. Both HNE and methacholine significantly increased the level of SLPI mRNA in submucosal glands in a dose-dependent manner (i.e., 357% of control level at 10(-7) M and 175% of control level at 10(-5) M, respectively). These findings indicate that human airway submucosal glands can transcribe 30-fold or more SLPI mRNA than the superficial epithelium and that SLPI mRNA transcription and secretion are regulated by both HNE and muscarinic receptors.

Adult↗