Search PubMed⌕ Search

Biomedical subjects

T Kawano

Publications and source records attributed to T Kawano.

At least 181 records · Page 10Linked to original sources
PubMed1998

[Langerhans cell histiocytosis in the hypothalamus: a case report].

A case of Langerhans cell histiocytosis (LCH) in the hypothalamus is presented. A 52 year old man with eosinophilic granuloma of the lung was referred to our hospital. He complained of headache, easy fatigability, high fever, and voiding large quantities of urine, but was otherwise asymptomatic. T1-weighted images demonstrated a small mass in the hypothalamus. After about six months, the mass had grown to 2 cm in diameter. Surgery was performed by a pterional approach and a biopsy specimen was collected. Light microscopic examination of sections of the biopsy specimen showed polymorphous cellular infiltration by histiocytic cells, eosinophils, neutrophils, and lymphocytes. Electron microscopy showed Langerhans cells and Birbeck granules in the cytoplasm. The histological diagnosis was LCH, multifocal type. After low-dose radiation therapy, the mass gradually decreased in size. The clinicopathological features, neuroradiological findings, and treatment are briefly discussed.

Combined Modality Therapy↗
PubMed1998

Allogeneic peripheral blood stem cell transplantation for standard-risk leukemia. A multicenter pilot study: Japanese experience. Japan Blood Cell Transplantation Study Group.

A multicenter phase II study of allogeneic peripheral blood stem cell transplantation (allo-PBSCT) was conducted. Twenty-two patients (median age, 36 years) with standard-risk leukemia were transplanted with G-CSF-mobilized PBSC from an HLA-identical sibling donor, and received cyclosporine and methotrexate for GVHD prevention. Median days to ANC >500/microl and platelets >50,000/microl were 12 (9-20) and 16 (11-32), respectively. Grade II-IV acute GVHD developed in 6/21 (29%) and extensive chronic GVHD in 12/20 (60%). These observations indicate that allo-PBSCT is characterized by rapid hematologic engraftment, no increase of acute GVHD and an increased risk of chronic GVHD, and can be used as an alternative to allogeneic bone marrow transplantation.

Adolescent↗
PubMed1998

[Endoscopic diagnosis of early cancer in the esophagogastric junctional region].

The endoscopic diagnosis of early esophageal and gastric cancers located within 2 cm above and below the esophagogastric junction (EGJ) is discussed. We reviewed 25 cases (10 mucosal cancers and 15 submucosal cancers). Histologically, early cancers frequently appeared as type IIc lesions (16/25: 64%). There was no relationship between tumor size and the depth of invasion of cancer lesions, and most of the lesions were well or moderately differentiated carcinomas. Endoscopically, homogenous redness with a thin white coating, some granular appearance, and easy bleeding were very important factors for the diagnosis of early gastric cancer. For superficial esophageal cancer, differential diagnosis from reflux esophagitis is correctly performed with the endoscopic dye (lugol)-staining method and biopsy. In order not to overlook early cancer at the EGJ, this area should be observed with sufficient air inflation by the U-turn or J-turn method using a frontal-view panendoscope.

Adult↗
PubMed1997

Requirement for Valpha14 NKT cells in IL-12-mediated rejection of tumors.

A lymphocyte subpopulation, the Valpha14 natural killer T (NKT) cells, expresses both NK1.1 and a single invariant T cell receptor encoded by the Valpha14 and Jalpha281 gene segments. Mice with a deletion of the Jalpha281 gene segment were found to exclusively lack this subpopulation. The Valpha14 NKT cell-deficient mice could no longer mediate the interleukin-12 (IL-12)-induced rejection of tumors. Although the antitumor effect of IL-12 was thought to be mediated through natural killer cells and T cells, Valpha14 NKT cells were found to be an essential target of IL-12, and they mediated their cytotoxicity by an NK-like effector mechanism after activation with IL-12.

Animals↗
PubMed1997

CD1d-restricted and TCR-mediated activation of valpha14 NKT cells by glycosylceramides.

Natural killer T (NKT) lymphocytes express an invariant T cell antigen receptor (TCR) encoded by the Valpha14 and Jalpha281 gene segments. A glycosylceramide-containing alpha-anomeric sugar with a longer fatty acyl chain (C26) and sphingosine base (C18) was identified as a ligand for this TCR. Glycosylceramide-mediated proliferative responses of Valpha14 NKT cells were abrogated by treatment with chloroquine-concanamycin A or by monoclonal antibodies against CD1d/Vbeta8, CD40/CD40L, or B7/CTLA-4/CD28, but not by interference with the function of a transporter-associated protein. Thus, this lymphocyte shares distinct recognition systems with either T or NK cells.

Animals↗
PubMed1997

Inhibitory effects of HepG2 cell-derived apolipoprotein A-I-containing lipoproteins on cholesteryl ester accumulation in macrophages.

We investigated the mechanisms of inhibitory effects on foam cell formation of apolipoprotein A-I-containing lipoproteins secreted by HepG2 cells (HepG2-HDL) using mouse peritoneal macrophages. When macrophages were incubated with acetylated low-density lipoprotein (acetyl-LDL) in the presence of HepG2-HDL, cholesterol ester (CE) accumulation in cells was reduced by 63%. This inhibitory capacity was almost similar to that of plasma high-density lipoprotein (HDL). When macrophages were converted to foam cells with acetyl-LDL and then reacted with HepG2-HDL or plasma HDL, the HDL-induced CE reduction was 2.2-fold greater than HepG2-HDL. Similar results were obtained using apo E-free HepG2-HDL. Since the inhibitory effect of HDL on acetyl-LDL-induced CE accumulation in macrophages is due largely to its cholesterol efflux capacity, these results suggest the presence of an additional mechanism for the inhibition of CE accumulation by HepG2-HDL. To investigate the mechanism, acetyl-LDL was reisolated from HepG2-HDL by Sephacryl S-300 gel filtration after incubation in a cell-free system. Reisolated acetyl-LDL showed a significant reduction in electrophoretic mobility. The extent of CE accumulation by reisolated acetyl-LDL was reduced by 20% compared with control acetyl-LDL. Moreover, its endocytic degradation by macrophages was reduced by 28%. HepG2-HDL also inhibited macrophage degradation of acetyl-LDL as well as oxidized LDL, a likely atherogenic lipoprotein. This inhibitory effect was ascribed to the HepG2-HDL subfraction containing pre-beta HDL. Our results indicated that apo A-I-containing lipoproteins as a physiological model of nascent HDL may inhibit foam cell formation by reducing ligand activity of atherogenic lipoproteins. These data possibly suggest inhibitory function of nascent HDL for the formation of foam cells in vivo.

Animals↗
PubMed1997

The leech excitatory peptide, a member of the GGNG peptide family: isolation and comparison with the earthworm GGNG peptides.

A member of the GGNG peptide family was isolated from Hirudo nipponia (leech). GGNG peptides had only been isolated previously from earthworms. The C-terminus structure of the leech peptide, LEP (leech excitatory peptide), was -Gly-Gly-Asn-amide, while that of the earthworm peptides, EEP (earthworm excitatory peptide), was -Gly-Gly-Asn-Gly. LEP exerted 1000-fold more potent activities on leech gut than did EEP-2. On the other hand, EEP-2 was 1000-fold more potent than LEP on the crop-gizzard of the earthworm. Analog peptides of LEP and EEP-2 were synthesized, and the myoactive potency of each analog on the leech and earthworm tissues was compared.

Amino Acid Sequence↗
PubMed1997

Synchronous multiple colorectal adenocarcinomas.

BACKGROUND: The object of the present work was to characterize clinical features and the quality of preoperative examinations in patients with synchronous colorectal carcinomas, and to compare the incidence of associated benign polyps with our findings in patients with a single malignant lesion. METHODS: A retrospective evaluation of 225 patients with primary colorectal carcinoma revealed 9 cases (4.0%) of synchronous colorectal carcinomas. RESULTS: The synchronous colorectal carcinomas were located in the same anatomical segment in 7 patients and were divided into different segments in 2 patients. The accuracy of preoperative diagnosis was 55.6% by endoscopy alone and 66.7% by double contrast barium enema (DCBE) alone, while the rate was 77.8% when colonoscopy and DCBE were combined. There was a higher incidence of associated benign polyps in the group with synchronous colorectal carcinomas (55.6%) versus 28.7% for a single carcinoma (P < 0.05). The main reason why multiple lesions could not be identified preoperatively was that the distal lesions prevented examination of the proximal lesions. CONCLUSIONS: At the time of surgical resection, it is important to ascertain preoperatively whether or not a second lesion exists. If synchronous polyps are present in patients with synchronous colorectal carcinomas, they should be ablated to reduce the risk of metachronous colorectal carcinoma.

Adenocarcinoma↗
PubMed1997

Epidemiological survey of moyamoya disease in Korea.

To both clarify the current clinico-epidemiological features of Moyamoya disease in Korea as well as compare these cases with Japanese patients, 451 cases were collected from 26 Korean major neurosurgical institutes and 296 definite cases were analyzed statistically. Although the Korean age distribution patterns of Moyamoya disease showed two peaks, similar to Japanese patients, the Korean pattern was shifted to the right thus indicating Korean adult population to be 20% higher than that of Japanese patients. The female/male ratio was 1:3, which was slightly less than that for Japanese. The family occurrence rate in Koreans was 1.8%. The incidence of cerebral infarction and bleeding in Koreans was higher while transient ischemic attack (TIA) and seizure were less than that of Japanese. The incidence of infarction in children and of hemorrhage in children and adults were also statistically higher in Koreans. The incidence of hemorrhage was higher in females than in males. Both the age at onset and sex affected the disease type. Single encephalo-duro-arterio-synangiosis (EDAS) was performed on 87.6% of all surgical cases. Although the incidence of bleeding was higher in Korea, the outcomes of the patients were similar to that of the Japanese patients. Although Korean Moyamoya disease showed a relatively higher incidence of hemorrhage and adult onset, the overall clinical background was similar to that of Japanese patients.

Adolescent↗
PubMed1997

Clinical features of probable moyamoya disease in Japan.

To clarify the current clinical features of probable Moyamoya disease in Japan, 180 cases were analyzed based on the cases collected by the Research Committee on Spontaneous Occlusion of the Circle of Willis of the Ministry of Health and Welfare, Japan. Although the age distribution patterns of probable Moyamoya disease showed two peaks similar to that of definite cases, the pattern shifted to the right thus indicating a reversed children versus adult ratio. The female/male ratio was 1.65, which was not significantly different from that observed in definite cases. The family occurrence rate was 6.7%. The incidence of cerebral infarction and bleeding in probable cases was higher than that in definite cases. The incidence of hemorrhage was higher in females than in males. Angiographically probable cases were at earlier stages in comparison to definite cases. The rebuild-up phenomenon in electroencephalograms was less detectable than in definite cases. Surgical procedures were performed in 63.3% of all cases and approximately 81% of them underwent bypass surgery. Single encephalo-duro-arterio-synangiosis, direct bypass and combined bypass procedures were performed in 35, 40 and 25% of all surgical cases, respectively. Although the incidence of bleeding was higher in the probable cases, the outcomes of the patients were similar to that of the definite cases except for mortality. Approximately 7% of the probable cases developed into definite type within an average 6.6 year follow-up period. The majority of probable Moyamoya disease cases thus seems to have somewhat different clinical characteristics from the definite disease cases.

Adolescent↗
PubMed1997

Mutations in the CLCN5 gene in Japanese patients with familial idiopathic low-molecular-weight proteinuria.

Familial idiopathic low-molecular-weight proteinuria (FILMWP) is a renal proximal tubulopathy that occurs predominantly in males. FILMWP is characterized by mild proteinuria consisting of low-molecular-weight proteinuria, aminoaciduria and relatively conserved renal function, but without rickets. To determine whether FILMWP is related to the CLCN5 gene, which is responsible for Dent's disease and two related disorders, we analyzed the CLCN5 gene from four Japanese families with FILMWP. We identified two novel mutations: one was a single base insertion at codon 520 serine in exon 10 and the other was a single base deletion at codon 403 tyrosine in exon 8. These mutations caused a shift in the reading frame, resulting in synthesis of truncated CLC5 proteins that lacked 220 (29%) and 314 (42%) amino acids, respectively. These mutations were demonstrated to cosegregate with the disease in two families, respectively. We conclude that the CLCN5 gene is responsible for this proximal renal tubulopathy in some Japanese families and that FILMWP is possibly a variant of Dent's disease.

Alleles↗
PubMed1997

A major glycoprotein of Xenopus egg vitelline envelope, gp41, is a frog homolog of mammalian ZP3.

A predominant glycoprotein in the vitelline envelope (VE) of the anuran Xenopus laevis is gp41, known to be proteolytically converted from gp43 of the coelomic egg envelope concomitant with the acquisition of egg fertilizability. To characterize the protein core of gp41, purified gp41 from VE was digested with lysyl endopeptidase, and peptides isolated from the digests were sequenced for amino acids to design degenerate primers for polymerase chain reaction. By reverse transcription-polymerase chain reaction with a poly(A)+ RNA from the ovary of an ovulated female Xenopus, a specifically amplified band was obtained and sequenced. The upstream and downstream sequences of the sequenced region were completed by 5'- and 3'-rapid amplification of cDNA ends, respectively. The cDNA, referred to as gp43 cDNA, comprises 1423 base pairs and contains one open reading frame with a sequence for 460 amino acids. The predicted amino acid sequence of gp43 cDNA has a close similarity with that of mammalian ZP3. Northern blot and in situ hybridization studies indicated that gp43 mRNA is expressed in oocytes, particularly in the previtellogenic oocytes. A comparison of the N-terminal sequences of gp41 and gp43 strongly suggested that gp41 is generated at least by processing of the N-terminal portion of gp43 with oviductin.

Amino Acid Sequence↗
PubMed1997

Detection and classification of early squamous cell esophageal cancer.

The authors analyzed 230 cases of T1 cancer of the thoracic esophagus resected in our surgical department between 1985 and 1996. This study showed that mucosal cancer was superior to submucosal cancer with respect to the 5-year survival rate (84% vs 64%), the incidence of lymph node metastasis (2% vs 42%) and the incidence of vascular invasion (8% vs 79%); therefore, the true early cancer of the esophagus can be defined as mucosal cancer of the esophagus. As for endoscopic classification, 93% of the 0-IIb subtype lesion and 80% of the 0-IIc subtype were mucosal cancer. Endoscopic staining with Lugol's solution can produce more precise information in the diagnosis of such flat lesions. Important points in screening for the detection of mucosal cancer of the esophagus include: (i) esophagoscopy for patients with only slight esophageal symptoms; (ii) annual endoscopic examination for high-risk populations; and (iii) endoscopic staining with Lugol's solution for abnormal findings on conventional endoscopy.

Carcinoma, Squamous Cell↗
PubMed1997

Role of progesterone in capillary permeability in hyperstimulated rats.

The role of progesterone in capillary permeability, which may be causally related to the pathophysiology of ovarian hyperstimulation syndrome (OHSS), was investigated in immature rats. A total of 96 female Wistar rats aged 22 days were given 10 IU of equine chorionic gonadotrophin daily for 4 consecutive days, and given 30 IU of human chorionic gonadotrophin on the fifth day to produce hyperstimulated manifestations. On the sixth day, groups of 12 rats each received RU486 at a dose of 0, 1, 2.5, 5, 10, 15 or 20 mg/kg (groups 1-7), or RU486 at 5 mg/kg combined with 6alpha-methyl-17alpha-hydroxy-progesterone acetate at 10 mg/kg (group 8). On the 7th day, the ovarian weight and capillary permeability of all rats were determined. Capillary permeability was evaluated from the Evans blue dye (EB) content in the ovaries and the EB level in peritoneal irrigated fluid at 30 min after the intravenous injection of EB. The peritoneal fluid EB level was significantly lower in groups 3, 4, and 5 than in the vehicle group. However, the peritoneal EB level in group 7 was higher than in the vehicle group, although not significantly. These findings demonstrated that RU486 has two divergent effects on capillary permeability, depending on the dose administered. In group 8, on the other hand, the peritoneal EB level and ovarian EB content were significantly higher than the corresponding values in group 4, respectively, suggesting that progesterone has a role in capillary permeability and ovarian enlargement. These results imply that progesterone may contribute, at least in part, to the pathophysiology of OHSS in this experimental model.

Adrenocorticotropic Hormone↗
PubMed1997

Strip biopsy to treat esophageal granular cell tumor.

Esophageal granular cell tumors are rare neoplasms. We successfully treated a 35-year-old Japanese man with an esophageal granular cell tumor without any complications using strip biopsy. Endoscopic ultrasonography revealed a hypoechoic tumor with a diameter of 8 mm that was confined to the submucosal layer. A strip biopsy done with a two-channel endoscope completely resected the tumor. Six months later, no abnormal findings were recognized in the resected area. Therefore we propose that strip biopsy be considered as a viable alternative treatment for esophageal granular cell tumor, depending on the histologic character, tumor size, and depth of tumor infiltration.

Adult↗