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Biomedical subjects

A Morita

Publications and source records attributed to A Morita.

At least 19 recordsLinked to original sources
PubMed2000

p41 as a possible marker for cell death is generated by caspase cleavage of p42/SETbeta in irradiated MOLT-4 cells.

We have reported previously that X-irradiated MOLT-4 cells during their rapid cell death exhibited dose and time dependently a new protein named p41 detected by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). An antibody, AM-1, raised against partial peptide of p41 stained two spots, p41 and p42, unexpectedly. Amino acid sequence analysis of partial peptides showed homology between p41 and a putative oncogene, set. In the present study, N-terminal amino acid sequencing of p41 and p42, and polyclonal antibodies newly prepared against different partial peptide sequences revealed that p41 was a N-terminal truncation form of p42, and p42 was identified as SETbeta. The cleavage site was at carboxyl end of SNHD 18 of p42. Radiation-induced p42 cleavage as well as apoptotic cell death was suppressed by a caspase-specific inhibitor Ac-DEVD-CHO but not by Ac-YVAD-CHO. Further in vitro cleavage experiments with recombinant p42 and either irradiated cell extracts or recombinant caspases concluded that the cleavage of p42 into p41 was catalyzed by caspase(s) mainly by caspase-7. One of newly raised antibodies, AM-4, specific to p41 or specific to cleavage site of p42, was found useful enabling simple detection of p41 by 1-D PAGE instead of laborious 2-D PAGE. p41 may serve as a marker of apoptotic cell death.

Amino Acid Sequence↗
PubMed2000

Involvement of SAPK/JNK pathway in X-ray-induced rapid cell death of human T-cell leukemia cell line MOLT-4.

We found that SAPK/JNK was phosphorylated during X-ray-induced rapid cell death of MOLT-4 cells and that acid Sphingomyelinase inhibitor D609 suppressed the rapid cell death as well as phosphorylation of SAPK/JNK. Also C2-ceramide caused phosphorylation of SAPK/JNK, followed by rapid cell death. Further we isolated X-ray-resistant radiation-hybrid clones from MOLT-4 and 50 Gy irradiated mouse FM3A cells by repeated selections with 3 Gy irradiation. One of them named Rh-1a was found resistant to X-ray- as well as C2-ceramide-induced rapid cell death. Rh-1a cells had mouse DNA but no increase in either mouse or human Bcl-2 determined by Western blotting. Accumulation of p53 after X-irradiation was similarly observed in both parental MOLT-4 and Rh-1a cells. However, contrasting to prolonged and prominent phosphorylated status of SAPK/JNK in MOLT-4 cells, Rh-1a cells exhibited short transient increase and FM3A cells showed no increase of phosphorylated status SAPK/JNK after X-irradiation. Therefore, SAPK/JNK activation is considered important in X-ray-induced rapid cell death or apoptosis of MOLT-4 cells.

Animals↗
PubMed2000

Cleavage and phosphorylation of XRCC4 protein induced by X-irradiation.

We report the p35 and p60 forms of XRCC4 protein, appearing in human leukemia MOLT-4 or U937 cells following X-irradiation or hyperthermia. p35 appeared in conjunction with the cleavage of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and the fragmentation of internucleosomal DNA, and was suppressed by Ac-DEVD-CHO. p35 was also produced in vitro by treating MOLT-4 cell lysate with recombinant caspases, suggesting that p35 was a caspase-cleaved fragment of XRCC4 in apoptotic cell death. p60 was sensitive to treatment with phosphatase or wortmannin and was undetectable in M059J cells deficient in DNA-PKcs. However, p60 was found in ataxia-telangiectasia cells after irradiation. These results indicated p60 as a phosphorylated form of XRCC4, requiring DNA-PKcs but not ataxia-telangiectasia mutated (ATM).

Androstadienes↗
PubMed2000

Identification of a novel, dendritic cell-associated molecule, dectin-1, by subtractive cDNA cloning.

Dendritic cells (DC) are special subsets of antigen presenting cells characterized by their potent capacity to activate immunologically naive T cells. By subtracting the mRNAs expressed by the mouse epidermus-derived DC line XS52 with the mRNAs expressed by the J774 macrophage line, we identified five novel genes that were expressed selectively by this DC line. One of these genes encoded a type II membrane-integrated polypeptide of 244 amino acids containing a putative carbohydrate recognition domain motif at the COOH-terminal end. This molecule, termed "dectin-1," was expressed abundantly at both mRNA and protein levels by the XS52 DC line, but not by non-DC lines (including the J774 macrophage line). Dectin-1 mRNA was detected predominantly in spleen and thymus (by Northern blotting) and in skin-resident DC, i.e. Langerhans cells (by reverse transcription-polymerase chain reaction). Affinity-purified antibody against dectin-1 identified a 43-kDa glycoprotein in membrane fractions isolated from the XS52 DC line and from the dectin-1 cDNA-transfected COS-1 cells. His-tagged recombinant proteins containing the extracellular domains of dectin-1 showed marked and specific binding to the surface of T cells and promoted their proliferation in the presence of anti-CD3 monoclonal antibody at suboptimal concentrations. These in vitro results suggest that dectin-1 on DC may bind to as yet undefined ligand(s) on T cells, thereby delivering T cell co-stimulatory signals. Not only do these results document the efficacy of subtractive cDNA cloning for the identification of unique genes expressed by DC, they also provide a framework for studying the physiological function of dectin-1.

Amino Acid Sequence↗
PubMed2000

Cloning of a second dendritic cell-associated C-type lectin (dectin-2) and its alternatively spliced isoforms.

Using a subtractive cDNA cloning strategy, we isolated previously five novel genes that were expressed abundantly by the murine dendritic cell (DC) line XS52, but not by the J774 macrophage line. One of these genes encoded a unique, DC-associated C-type lectin, termed "dectin-1." Here we report the characterization of a second novel gene that was also expressed in a DC-specific manner. Clone 1B12 encoded a type II membrane-integrated polypeptide of 209 amino acids containing a single carbohydrate recognition domain motif in the COOH terminus. The expression pattern of this molecule, termed "dectin-2," was almost indistinguishable from that for dectin-1; that is, both were expressed abundantly at mRNA and protein levels by the XS52 DC line, but not by non-DC lines, and both were detected in spleen and thymus, as well as in skin resident DC (i.e. Langerhans cells). Interestingly, reverse transcriptase-polymerase chain reaction and immunoblotting revealed multiple bands of dectin-2 transcripts and proteins suggesting molecular heterogeneity. In fact, we isolated additional cDNA clones encoding two distinct, truncated dectin-2 isoforms. Genomic analyses indicated that a full-length dectin-2 (alpha isoform) is encoded by 6 exons, whereas truncated isoforms (beta and gamma) are produced by alternative splicing. We propose that dectin-2 and its isoforms, together with dectin-1, represent a unique subfamily of DC-associated C-type lectins.

Alternative Splicing↗
PubMed2000

Alterations of extracellular matrix induced by tobacco smoke extract.

Epidemiologic studies have indicated the association between tobacco smoking and skin aging, but the exact mechanism of tobacco smoke-induced premature skin aging is currently unknown. In this study, we investigated the alterations of collagen, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human fibroblasts treated with tobacco smoke extract. Human fibroblasts were exposed to different concentrations of water-soluble extract from tobacco smoke. Human fibroblasts irradiated with ultraviolet A1 (UVA1) were used as positive controls because the mechanism of UVA1-mediated MMP expression has been well characterized. The expression of MMP and TIMP was analyzed semiquantitatively following reverse transcriptase-polymerase chain reaction. Production of type I and type III collagens was detected by Western blotting and biosynthesis of new collagen was assessed by 3H-proline incorporation. Upon treatment with tobacco smoke extract or UVA1 irradiation, the expression of MMP-1 and MMP-3 mRNA was significantly increased in a dose-dependent manner. Maximum induction was observed with 25 microl/ml tobacco smoke extract. In contrast, the expression of TIMP-1 and TIMP-3 mRNA remained unchanged. Western blotting of the supernatant revealed that type I and type III collagens were decreased as compared with untreated controls. Collagen biosynthesis was significantly reduced by 40.1% following treatment with 25 microl/ml tobacco smoke extract. Sodium azide, L-ascorbic acid and Trolox (a water-soluble vitamin E) prevented both the UVA1- and the tobacco-induced alteration of MMP-1. These observations suggest that the imbalance of connective tissue matrix components might contribute to the molecular basis for premature skin aging in smokers. They also suggest that reactive oxygen species including singlet oxygen mediate this process.

Adult↗
PubMed2000

Characterization of isoforms of hexose kinases in rice embryo.

Hexose kinases in rice embryos have been characterized. Six isoforms were detected: i.e. three glucokinases (GK1-3), two hexokinases (HK1 and HK2) and one fructokinase (FK1). Out of these, GK3, HK1 and HK2 were inhibited by mannoheptulose and glucosamine, known inhibitors of hexokinase activity. These inhibitors are also known to be modulators of sugar sensing processes. The results suggest that GK3, HK1 and HK2 may play a role in sensing the cellular sugar status in the rice embryo.

Fructokinases↗
PubMed2000

Ultraviolet A1 (340-400 nm) phototherapy for scleroderma in systemic sclerosis.

BACKGROUND: The presence of an inflammatory infiltrate consisting of helper T cells and a dysregulated matrix metabolism leading to excessive deposition of collagen are two pathogenetic factors responsible for the developments of fibrosis and sclerosis in patients with systemic sclerosis. In previous studies, ultraviolet A1 (UVA1) radiation phototherapy was shown to deplete skin-infiltrating T cells through the induction of T-cell apoptosis and to up-regulate the expression of matrixmetalloproteinase-1 (collagenase-1) in dermal fibroblasts. OBJECTIVE: Our purpose was to determine whether UVA1 phototherapy is effective for systemic sclerosis. METHODS: Lesional skin on the forearms of patients with systemic sclerosis (diffuse type, n =3; limited type, n =1) was exposed to medium-dose UVA1 radiation (60 J/cm(2)) daily. RESULTS: In all patients studied, UVA1 phototherapy-treated skin lesions were markedly softened after 9 to 29 exposures. Clinical improvement was associated with an increase in (1) joint passive range of motion values (P <.05), (2) skin temperature (thermography, P <.05), and (3) cutaneous elasticity (cutaneous elastometry, P <.05). Histologic evaluation of skin specimens obtained before and after UVA1 phototherapy revealed loosening of collagen bundles and the appearance of small collagen fibers. CONCLUSION: These studies indicate that UVA1 phototherapy is effective for patients with systemic sclerosis.

Aged↗
PubMed2000

A rapid and efficient system of Agrobacterium infection-mediated transient gene expression in rice Oc cells and its application for analysis of the expression and antisense suppression of preprophytosulfokine, a precursor of phytosulfokine-a, encoded by OsPSK gene.

A rapid and efficient system for Agrobacterium infection-mediated transient gene expression in rice has been developed. Using this system, transient expression of preprophytosulfokine, a precursor of phytosulfokine-a, encoded by OsPSK gene was analyzed. The results suggest that the Agrobacterium infection-mediated transient gene expression system is as efficient in rice Oc cells as in tobacco BY-2 cells and might be useful for rapid analysis not only of foreign gene expression, but also of antisense gene suppression.

Actins↗
PubMed2000

Primary angiitis of the central nervous system as a first presentation in Hodgkin's disease: a case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Granulomatous angiitis of the central nervous system is a rare cause of neurological deterioration. It is often diagnosed posthumously, and a high index of suspicion is necessary to make the correct diagnosis on a timely basis. CLINICAL PRESENTATION: A 27-year-old woman presented to the emergency room with complaints of worsening headache, nausea, and vomiting for 10 days, which were preceded by swelling of her tongue. At the examination, she had mild ocular tenderness, but no cranial nerve abnormalities. Radiographic examination revealed a right temporal lobe area with edema, and mild contrast enhancement was noted on computed tomography and magnetic resonance imaging. A similar but smaller region was present in the left frontal lobe. INTERVENTION: Stereotactic biopsy of the left temporal lobe revealed granulomatous angiitis. Further workup revealed Hodgkin's disease in the mediastinum. Dexamethasone as well as chemotherapy for Hodgkin's disease was initiated. The patient's symptoms resolved, and she returned to work with her disease in remission. CONCLUSION: Previous reports of central nervous system angiitis have shown an association with Sjogren's syndrome, herpes zoster infection, human immunodeficiency virus, and Hodgkin's disease. A review of the literature revealed a total of 12 patients with central nervous system angiitis and Hodgkin's disease. As a group, these patients had very poor outcomes. However, of six patients who presented with central nervous system angiitis and concurrent Hodgkin's disease and who underwent aggressive treatment for both conditions, three had a full recovery, two had a partial recovery, and one died.

Adult↗
PubMed2000

Increased expression after X-irradiation of MUC1 in cultured human colon carcinoma HT-29 cells.

The effect of X-irradiation on production of MUC1 was studied with human colon carcinoma HT-29 cells. As evaluated by immunocytochemical staining, the percentages of MUC1-positive cells in cells at 4 days after 6 Gy irradiation and in unirradiated control cells were 52 +/- 3.5% (n = 6) and 26 +/- 2.8% (n = 6), respectively. Flow-cytometric analysis of living cells showed that MUC1 began to rise from day 1, reaching a plateau by day 4 after 6 Gy irradiation. Western blot analysis with monoclonal antibody MY.1E12 against glycosylated MUC1 (mature form) showed dose-dependent increases of two bands (500 and 390 kDa) corresponding to two polymorphic MUC1 alleles. Premature forms of MUC1 (350 and 240 kDa) were detectable with monoclonal antibody HMFG-2 only in irradiated cells, suggesting that new core protein synthesis had been induced. The transcriptional activity of the MUC1 gene was analyzed in terms of transient expression of MUC1-CAT reporter plasmids containing 5'-flanking sequences of the MUC1 gene fused to the bacterial chloramphenicol acetyltransferase (CAT) gene. The results of CAT assay indicate that enhanced expression of MUC1 in irradiated HT-29 cells was due to upregulation of MUC1 transcription, and required the upstream promoter.

Antibodies, Monoclonal↗
PubMed2000

Neuroendoscopic aqueductal stent placement procedure for isolated fourth ventricle after ventricular shunt placement. Case report.

Isolated fourth ventricle (IFV) is a rare complication in patients who undergo shunt placement, and it is not easily corrected by surgical procedures. The authors report a case of IFV that was successfully treated with an aqueductal stent placed under direct visualization by using a neuroendoscope. This 36-year-old suffered meningitis after partial resection of a brainstem pilocytic astrocytoma, and subsequently developed hydrocephalus for which a ventriculoperitoneal shunt was placed. Nine months later, the patient presented with progressive cerebellar ataxia, and magnetic resonance imaging revealed slitlike supratentorial ventricles and a markedly enlarged fourth ventricle, which were compatible with the diagnosis of IFV. The surgical procedure described was performed under visualization through a styletlike slim optic fiberscope inserted into a ventricular catheter. The catheter, with the endoscope inside it, was passed through the foramen of Monro and then through the aqueduct to reach the enlarged fourth ventricle, where membranous occlusion of the foramen of Magendie was clearly visualized. The tip of the catheter was placed in the fastigium of the fourth ventricle. After the procedure, the size of the fourth ventricle was reduced and the patient's symptoms improved. Thus, it is concluded that endoscopic aqueductal stent placement is a simple and safe surgical procedure for treatment of IFV.

Adult↗
PubMed2000

A transparent sheath for endoscopic surgery and its application in surgical evacuation of spontaneous intracerebral hematomas. Technical note.

The authors advocate the use of a transparent sheath for guiding an endoscope, a simple and unique tool for endoscopic surgery, and describe preliminary results of its application in the evacuation of hypertensive intracerebral hematomas. This sheath is a 10-cm-long tube made of clear acrylic plastic, which greatly improves visualization of the surgical field through a 2.7-mm nonangled endoscope inserted within. Between April 1997 and December 1998, the authors performed endoscopic evacuation of intracerebral hematomas by using this sheath inserted into the patients' heads through a burr hole. In nine consecutive cases in which the hematoma was larger than 40 ml in volume, nearly complete evacuation (86-100%) of the lesion was achieved without complication. Excellent visualization of the border between the brain parenchyma and the hematoma facilitated accurate intraoperative orientation, and also allowed easy identification of the bleeding point. Thus, this combination of sheath and endoscope achieves both minimal invasiveness and the maximum extent of hematoma removal with secure hemostasis. This tool will reduce the inherent disadvantage of endoscopic procedures and may expand their application in other areas of neurosurgical management.

Aged↗
PubMed2000

Risk of rupture from incidental cerebral aneurysms.

OBJECT: Controversy still exists about the risk estimation for rupture of untreated saccular aneurysms presenting for causes other than subarachnoid hemorrhage (SAH). The object of this study was to address this issue. METHODS: Between January 1976 and December 1997 in the Aizu Chuou Hospital, 62 patients underwent observation for more than 6 months for saccular, nonthrombotic, noncalcified unruptured aneurysms at locations not related to the cavernous sinus, which were detected in cerebral angiography studies performed for causes other than SAH. Clinical follow-up data in those 62 patients were reviewed to identify the risk of SAH. All patients were followed until July 1998, with the observation period ranging from 6 months to 17 years (mean 4.3 years). Seven patients (11.3%) developed SAH confirmed on computerized tomography (CT) scanning at a mean interval of 4.8 years, six of whom died and one of whom recovered with a major deficit. In addition, one patient died of the mass effect of the aneurysm, and another after sudden onset of headache and vomiting. The 5- and 10-year cumulative risks of CT-confirmed SAH calculated by the Kaplan-Meier method were 7.5% and 22.1%, respectively, for total cases, 33.5% and 55.9%, respectively, for large (> 10 mm) aneurysms, and 4.5% and 13.9%, respectively, for small (< 10 mm) aneurysms. CONCLUSIONS: Although based on a relatively small, single-institution series, our data indicated that the risk of rupture from incidental, intradural, saccular aneurysms was higher than previously reported, and may support preventive surgical treatment of incidental aneurysms, considering the fatality rate of SAH.

Aged↗
PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗
PubMed2000

[Biweekly low-dose cisplatin and 5-fluorouracil combination chemotherapy for advanced gastrointestinal carcinoma].

Biweekly intravenous infusions of low-dose cisplatin (CDDP) and 5-fluorouracil (5-FU) were evaluated in 80 patients with advanced or recurrent gastric, colorectal, pancreatic or gallbladder adenocarcinoma. CDDP was given biweekly at a dose of 15 mg/m2 infused for 30 minutes, and 5-FU 375 mg/m2 was infused for 2 hours as many times as possible. The response rate among patients with gastric cancer was 26%, colorectal cancer 10%, pancreatic cancer 7.7%, and gallbladder cancer 42.9%. The response rates were not so high, but the median survival time of patients with recurrent gastric cancer was 17.3 months, pancreatic cancer 6.7 months, and gallbladder cancer 10.7 months. A patient with unresected advanced pancreatic head cancer with liver and para-aortic lymph node metastases received this therapy 38 times, and lived for 54 months. No severe side effects occurred in any of these cases. Thus, this chemotherapy could well be effective for the outcome of cases of advanced gastrointestinal carcinoma.

Adenocarcinoma↗