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Biomedical subjects

K Gotoh

Publications and source records attributed to K Gotoh.

At least 37 records · Page 2Linked to original sources

BCAP: the tyrosine kinase substrate that connects B cell receptor to phosphoinositide 3-kinase activation.

Tyrosine phosphorylation of adaptor proteins permits the B cell antigen receptor (BCR)-associated protein tyrosine kinases to regulate downstream effector molecules. Here, we report the identification of a novel B cell adaptor for phosphoinositide 3-kinase (PI3K), termed BCAP. Tyrosine phosphorylation of BCAP is mediated by Syk and Btk, thereby providing binding site(s) for the p85 subunit of PI3K. Disruption of the BCAP gene in the DT40 B cell line inhibits BCR-mediated phosphatidylinositol 3,4,5-trisphosphate generation, leading to impaired Akt response. Moreover, recruitment of PI3K to glycolipid-enriched microdomains (GEMs) is significantly attenuated in the absence of BCAP. Hence, these data suggest that BCAP bridges BCR-associated kinases to the PI3K pathway by regulating PI3K localization.

Adaptor Proteins, Signal Transducing↗

A case of eosinophilic cystitis in a 5-year-old boy.

Eosinophilic cystitis (EC) is rather an uncommon disease in childhood. A case of EC in a 5-year-old boy, in which open biopsy was needed for final diagnosis, is reported. After diagnosis, he was treated with pemirolast potassium followed-up with eosinophil cationic protein (ECP) in serum and urine. Eosinophil cationic protein is an appropriate marker of EC.

Child, Preschool↗

Sulfated fibroin, a novel sulfated peptide derived from silk, inhibits human immunodeficiency virus replication in vitro.

We prepared two kinds of sulfated silk fibroins, SclFib30 and SclFib31, which contain different amounts of sulfate. These sulfated silk fibroins have anti-HIV-1 activity in vitro, apparently due to interference with the adsorption of virus particles to CD4+ cells, and completely blocked virus binding to the cells at a concentration of 100 microg/ml. Sulfated fibroins also abolished cell-to-cell infection-induced syncytium formation upon cocultivation of MOLT-4 and MOLT-4/HIV-IIIB cells, suggesting that they would interfere with gp120 and prevent the formation of gp120/CD4 complex. Silk is used in biomaterials such as surgical sutures and is believed to be a safe material for humans. In accordance with low anticoagulant activity and high anti-HIV-1 activity against both X4 HIV-1 and R5 HIV-1 strains, sulfated silk fibroins have potential as antiviral material such for a vaginal anti-HIV formulation.

Animals↗

Mechanism of relaxant response to papaverine on the smooth muscle of non-pregnant rat uterus.

In the present paper, we examined a mechanism of the papaverine induced relaxation in the smooth muscle of non-pregnant rat uterus. The hyperosmotic 65 mM KCl (H-65K+)-or oxytocin-induced contraction in the uterus was inhibited by an addition of papaverine in a concentration-dependent manner. Papaverine did not increase both cAMP and cGMP contents in the uterus in the presence of H-65K+ or oxytocin. In fura 2 loaded muscles, papaverine did not affect an increase of [Ca2+]i level by high K+ or oxytocin. In permeabilized muscles, papaverine had no effect on the Ca2+-induced contraction. H-65K+ and oxytocin increased the rate of oxygen consumption 1.8 and 1.5 times higher than that in the resting condition, respectively. The increase of oxygen consumption in the H-65K+ or oxytocin was significantly inhibited by papaverine (1-100 microM). These results suggested that papaverine inhibits smooth muscle contraction mainly by inhibition of mitochondrial respiration in rat uterus as well as guinea pig ileum, which shows a highly spontaneous activity and a highly metabolic dependency of a contraction.

Animals↗

Postoperative changes in paraspinal muscle thickness after various lumbar back surgery procedures.

Damage to the paraspinal muscle after various lumbar back surgery procedures was evaluated by measuring the paraspinal muscle thickness preoperatively and postoperatively in 89 patients, 61 males and 28 females. There were 42 single interlaminar level procedures (SL group), 13 multiple interlaminar level procedures (ML group), and 34 posterolateral fusion procedures (PLF group). Changes in paraspinal muscle thickness were evaluated at more than 10 months after surgery, because muscle swelling continued as long as 10 months after surgery, and then reduced as the edema subsided. Postoperative serum creatine phosphokinase (CPK) level on postoperative day 2 was also measured. The decrease of paraspinal muscle thickness was significantly larger in the PLF group than in the SL group (-12.9% and -2.7%, respectively, p < 0.02). There was no significant correlation between postoperative serum CPK level and decrease of paraspinal muscle thickness. However, the postoperative elevation of serum CPK level was significantly higher in the PLF group than in the SL and ML groups (979 +/- 114 vs. 292 +/- 45 and 410 +/- 44 IU/l, respectively, p < 0.001). In conclusion, posterolateral fusion is the most invasive procedure of the paraspinal muscles in various lumbar back surgery procedures. Paraspinal muscle damage during lumbar back surgery may be one of the most important factors that causes atrophy of the muscles.

Adult↗

Comparative study of the toxic effects of gallium arsenide, indium arsenide and arsenic trioxide following intratracheal instillations to the lung of Syrian golden hamsters.

Toxic effects of gallium arsenide (GaAs), indium arsenide (InAs) and arsenic trioxide (As2O3) were studied in male Syrian golden hamsters. GaAs (7.7 mg/kg) and As2O3 (1.3 mg/kg) particles were instilled intratracheally twice a week a total of 16 times, while InAs (7.7 mg/kg) was instilled a total of 14 times. As a control, hamsters were treated with the vehicle, phosphate buffer solution. During the instillation period, the cumulative body weight gain of the InAs-, but not the GaAs- or As2O3-treated hamsters was suppressed significantly, when compared with the control group. Slight to severe inflammatory responses were observed in the lung for all treatment groups. The most severe inflammatory change, characterized by an accumulation of neutrophils and macrophages, exudation, thickness of the pleura and fibrotic proliferation was found in the InAs-treated hamsters. Extensive alveolar or bronchiolar cell hyperplasia with or without keratinizing squamous cell metaplasia was observed in almost all the InAs-treated hamsters. Furthermore, squamous cell metaplasia or squamous cell hyperplasia developed in some of the InAs-treated hamsters, but not in the GaAs- or As2O3-treated hamsters. Slight to mild lesions were found in the convoluted tubules of the kidney in both the GaAs and InAs groups. From the present study, the toxic potency of these particles was provisionally estimated to be in the following order: InAs > GaAs > As2O3, at the dosage level used in this study. Furthermore, there was evidence that InAs particles could induce pulmonary, renal or systemic toxicity, and as such, InAs particles may produce pulmonary precancerous change when instilled intratracheally into hamsters.

Animals↗

[A case of nonresectable scirrhous type gastric cancer successfully treated by low-dose cisplatin (CDDP), 5-fluorouracil (5-FU) and pirarubicin (THP)].

There have been few effective chemotherapeutic regimens for scirrhous type gastric cancer. Recently, the usefulness of combined cancer agent chemotherapy based on the concept of biochemical modulation has been reported. For example sequential MTX and 5-FU therapy, low-dose CDDP plus 5-FU, and the like. In this paper, we report the usefulness of low-dose CDDP plus 5-FU therapy in combination with pirarubicin (THP) for inoperable scirrhous type gastric cancer. A 32-year-old man who was suffering from scirrhous type gastric cancer with pyloric stenosis was treated with this regimen. Eight weeks after the start of therapy, his gastric capacity and lumen diameter had clearly increased, and he was taking ordinary meals. Ascites had also completely disappeared. CR has now been continued about 7 months. This regimen is considered to be promising for scirrhous type gastric cancers with a poor prognosis.

Adenocarcinoma, Scirrhous↗

An external ion microbeam for studies of biological samples.

A new external ion-beam system was developed and combined with a light ion-microbeam system in JAERI Takasaki. The system is designed for micro-particle-induced X-ray emission analysis of biological samples in air environment with 1 micron spatial resolution. One of the most serious problems in keeping such a high spatial resolution is multiple scattering in a beam exit window. Thin Kapton film (7.5 microns thick) was adopted as the exit window as well as a sample backing foil to minimize the distance between the film and samples. The lifetime of the foil under ion irradiation and spatial resolution of the external microbeam were investigated. The results shows that the film can endure sufficient long-time irradiation to take elemental maps and the resolution can be kept nearly 1 micron.

Biological Assay↗

Process of carboxylation of glutamic acid residues in the gla domain of human des-gamma-carboxyprothrombin.

In the absence of vitamin K (VK) or in the presence of VK antagonists, hepatic VK-dependent carboxylase activity is inhibited and des-gamma-carboxyprothrombin (DCP) is released into the blood. We analyzed the number of glutamic acid (Glu) residues and their positions in the Gla domain (GD) of DCP to investigate the gamma-carboxylation mechanism of VK-dependent carboxylase. Several DCPs were found in each subject studied. The 10 Gla residues of human prothrombin were carboxylated in order from the N-terminal (residues 26, 25, 16, 29, 20, 19, 14, 32, 7 and 6). The process of Glu carboxylation seemed to proceed three-dimensionally from inside to outside the molecule.

Adult↗

Multiple red blood cell antibodies produced by donor B lymphocytes after ABO-matched allogeneic bone marrow transplantation.

A 50-year-old man with AML[M2,t(8;21)] underwent BMT from his younger sister. At that time, he had no unexpected antibody and his blood type was O(+), CcDEe. The type of Kidd was not examined. The donor's blood type was O(+), CCDee, Jk(a+b-). One year after the BMT, the patient's blood type had changed to that of the donor's and anti-E antibody was detected. Despite the use of platelet concentrates (PCs) only, anti-c antibody was later identified. We conclude that there is a need to check red cell antibodies at regular intervals, even when using PCs only, for earlier detection of unexpected antibodies after BMT.

ABO Blood-Group System↗

Expression pattern of a newly recognized protein, LECT2, in hepatocellular carcinoma and its premalignant lesion.

Leukocyte cell-derived chemotoxin 2 (LECT2) is a recently isolated protein and has been shown to be synthesized by human hepatocytes. All hepatocytes show diffuse immunostaining for LECT2 within the cytoplasm. In the present study, an attempt was made to clarify the expression pattern of LECT2 in nine cases of low-grade malignant hepatocellular carcinoma (LGM-HCC) and five cases of advanced HCC and 19 cases of premalignant lesion, termed atypical hyperplasia (AH), using the indirect immunoperoxidase technique. Variable spotty to coarsely diffuse staining in the majority of cells, a mixture of positively staining and negatively staining areas, and essentially negative staining was observed within the cellular cytoplasm of AH, LGM-HCC and advanced HCC, respectively. The expression of LECT2 became weaker with the progression of multistep hepatocarcinogenesis. The data clearly demonstrate that LECT2 becomes essentially negative in full-blown HCC cells and that the histological distinction between AH and LGM-HCC is valid. It also seems likely that LECT2 is related to hepatocyte growth.

Adult↗

Augmentation ileocystoplasty and ileal ureter replacement for distal ureteral cancer in a patient with a contracted bladder.

BACKGROUND: A male patient with a solitary kidney and contracted bladder due to urinary tuberculosis presented ureteral obstruction caused by primary lower ureteral cancer. METHODS: Distal ureterectomy and urinary tract reconstruction consisting of ileal bladder augmentation and ileal ureter replacement with an antireflux procedure was performed. RESULTS/CONCLUSIONS: Postoperatively satisfactory voiding without residual urine was achieved.

Aged↗

Frameshift mutations in TGFbetaRII, IGFIIR, BAX, hMSH3 and hMSH6 are absent in lung cancers.

A genome-wide instability at simple repeat sequences characterizes gastrointestinal and endometrial cancers of the microsatellite mutator phenotype (MMP). The genes encoding transforming growth factor-beta receptor type II (TGFbetaRII), insulin-like growth factor II receptor (IGFIIR), Bcl-2 associated X protein (BAX), hMSH3 and hMSH6 have simple repeat sequences in their coding regions. Consequently, mutations in the single repeat sequences in these genes provide one major route for carcinogenesis in these cancers. We examined 43 non-small cell lung carcinomas and 16 small cell carcinomas for frameshift mutations in simple repeat sequences of TGFbetaRII, IGFIIR, BAX, hMSH3 and hMSH6. In addition, MMP was assessed using a primer set for BAT-26. None of 59 lung cancers exhibited frameshift mutations or MMP. It is concluded that somatic frameshift mutations in these genes and MMP do not constitute important mechanisms in lung carcinogenesis. The possibility of some sort of genetic instability undetectable as a form of MMP cannot be precluded.

Base Sequence↗

Dorsally sequestrated thoracic disc herniation--case report.

A 53-year-old male presented with a rare dorsally sequestrated thoracic disc herniation manifesting as acute low back pain and weakness. He had no history of trauma. Magnetic resonance (MR) imaging demonstrated a mass at T10-11 intervertebral level connected with the T-10 disc. Axial MR imaging showed the mass had surrounded and compressed the dural sac from the lateral and dorsal sites. MR imaging with gadolinium-diethylenetriaminepenta-acetic acid showed slight rim enhancement of the lesion. Computed tomography detected no abnormal calcification. The diagnosis was thoracic disc herniation. Laminectomy resulted in rapid and satisfactory recovery. The histological diagnosis was thoracic disc herniation. MR imaging was very effective for the diagnosis based on the connection between the mass and the disc space. The differential diagnosis includes metastatic epidural tumor, epidural hematoma, and epidural abscess.

Acute Disease↗

[Pharmacological study of weekly docetaxel in patients with metastatic breast cancer].

A pharmacological comparison of weekly administrations of docetaxel (TXT) and standard/conventional TXT was carried out among patients with metastatic breast cancer. Fifteen patients were enrolled in this study of weekly TXT (TXT: 40 mg/body/week x 3 with 1 week interruptions in 10 patients) and standard TXT (TXT: 60 mg/m2/3 weeks in 5 patients). The median dose intensity (DI) of weekly TXT (20.63 mg/m2/week) was similar to that of standard TXT, and the median relative dose intensity (RDI) of weekly TXT was 0.98. The median area under the plasma concentration-time curve (AUC) of weekly TXT (1.20 micrograms.h/ml) was smaller than that of standard TXT (1.87 micrograms.h/ml). Therefore, there were remarkable decreases in both median percent of decrease in neutrophil counts and grade 3, 4 neutropenia with weekly TXT. These pharmacological data show that weekly TXT is a well-tolerated and feasible schedule for the treatment of metastatic breast cancer.

Adult↗

Clinical implications of p53 autoantibodies in the sera of patients with non-small-cell lung cancer.

BACKGROUND: The presence of autoantibodies to p53 protein has been associated with the presence of p53 (also known as TP53) gene mutations in primary tumors and with poor prognosis. This study was undertaken to determine the clinical significance of p53 autoantibodies in patients with non-small-cell lung cancer (NSCLC). METHODS: We studied 188 consecutive patients with NSCLC who underwent pulmonary resection and for whom preoperative serum was available. The presence of p53 autoantibodies, detected by use of two amino-terminal and two carboxy-terminal peptides (20-30 mers) as antigens and an enzyme-linked immunosorbent assay, was related to various clinicopathologic parameters and to overexpression of p53 protein in the primary tumor. For 22 patients who had p53 autoantibodies before surgery, we also examined sera taken during postoperative follow-up. Reported P values are two-sided. RESULTS: Autoantibodies to p53 protein were detected in 38 patients. Patients with squamous cell carcinoma, those with more advanced disease (stage III-IV), and those with tumors that overexpressed p53 had a significantly higher incidence of p53 autoantibodies (P = .05,.0079, and .02, respectively). In all but one of the patients with postoperative serum samples, the antibody titer declined after surgery; however, there was no relationship between clinical course and this change in antibody titer. In addition, there was no relationship between the presence of p53 autoantibodies and overall survival in 171 patients who underwent potentially curative resection (P = .28); however, 13 patients with autoantibodies to amino-terminal peptides had a worse overall survival (P = .02). CONCLUSIONS: In NSCLC, the incidence of p53 autoantibodies is associated with histologic type, stage, and p53 overexpression--but not with patient survival. Our data do not support the clinical utility of p53 autoantibodies as diagnostic or prognostic markers in patients with NSCLC.

Adult↗

Genomic structure of MUNC18-1 protein, which is involved in docking and fusion of synaptic vesicles in brain.

MUNC18-1 (n-Sec1) is a brain-specific protein and is known to play a role in neurotransmitter release by mediating docking and fusion of synaptic vesicles to presynaptic membranes. The protein is also implicated in the cellular excretion process of hormones and other biological substances in other mammalian tissues and yeasts. We have studied the structure of mouse munc18-1 gene by sequencing the genomic munc18-1 gene and its 5'-flanking region. munc18-1 gene comprises 19 exons whose size ranges from 50 base pairs (2nd exon) to 1676 base pairs (19th exon) with a total gene size of approximately 56 kilobases. In the 5'-flanking region, there are several transcription factor binding sites such as for HSF2, Lyf-1, and Sp1 but no TATA or CAAT sequences. munc18-1 gene was mapped on mouse chromosome 2 between two anchor markers D2Mit152 and D2Mit242. Transfection experiments employing these and upstream sequences suggest the presence of a sequence(s) that negatively regulates the expression of munc18-1 gene.

Animals↗