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Biomedical subjects

N Mori

Publications and source records attributed to N Mori.

At least 199 records · Page 11Linked to original sources
PubMed1999

CEA-producing mucin-negative gastric signet-ring cell carcinoma with neuroendocrine markers: a case report.

Biopsy and autopsy materials excised from a 69-year-old woman were investigated. Serum carcinoembryonic antigen (CEA) showed a high value of 955 ng/mL. A plateaulike tumor was located in the gastric cardia and fundus to the entire gastric body. It showed severe proliferation and infiltration from the mucosa to the serosa. The tumor was comprised of signet-ring cells and poorly differentiated adenocarcinoma cells, which spread into the submucosa of the pylorus, duodenum, and jejunum. Signet-ring cells had a large, eccentric vesicular nucleus and a pale cytoplasmic inclusion. Poorly differentiated adenocarcinoma cells had a pleomorphic nucleus, small eosinophilic nucleolus, and abundant eosinophilic cytoplasm. Both neoplastic cells were positive for CEA, epithelial membrane antigen, Leu-7 (CD57), and neuron-specific enolase, and were negative for cytokeratin, vimentin, and periodic acid-Schiff, Alcian blue, and mucicarmine stains. Electron microscopy showed endocrine granules with a limiting membrane measuring approximately 238 nm in diameter in the cytoplasm. The authors diagnosed this patient as having mucin-negative gastric signet-ring cell carcinoma with neuroendocrine markers, which is suggested to exist among poorly differentiated adenocarcinoma, undifferentiated carcinoma, and signet-ring cell carcinoma.

Adenocarcinoma↗
PubMed1999

Primary advanced gastric small cell carcinoma: a case report and review of the literature.

We report a 73-yr-old man with primary advanced gastric small cell carcinoma, pure type. A large, Borrman type I tumor was located from the cardia to the entire gastric fundus and upper body. Atypical cells showed a round nucleus, small nucleolus, dense to granular chromatin, and scant cytoplasm. The histological findings indicates an advanced stage and exposure to the gastric serosa. Mitotic figures were observed. There was a proliferation of a sheet-like, solid pattern, but no rosette-like, sqamoid, or glandular patterns. The neoplastic cells were positive for Leu-7 (CD57) and 123C3 (CD56, neural cell adhesion molecule, NCAM) on the surface membrane. We diagnosed this case as primary advanced gastric small cell carcinoma, pure type, and report that Leu-7 and 123C3 monoclonal antibodies are useful markers for gastric small cell carcinoma. The 32 previously reported cases of gastric small cell carcinoma are also reviewed.

Aged↗
PubMed1999

Ac-mediated trans-activation of the Ds element in rice (Oryza sativa L.) cells as revealed by GUS assay.

A method using particle bombardment and beta-glucuronidase (GUS) assay was applied to rice callus for detecting the excision of the maize Ds element trans-activated by the Ac transposase source. Excision of Ds biolistically introduced into rice callus resulted in the restoration of the interrupted gus gene expression, allowing visual detection of trans-activation two days after bombardment. Only the transgenic callus lines expressing the Ac transposase gene and the wild-type callus co-transformed with Ac and Ds revealed GUS activity. Frequency of excision, estimated based on the relative GUS activity, ranged from 0.3% to 2.2%. Callus lines showing different levels of Ac transcripts revealed varying excision frequencies. At the later stages of callus growth after selection for the Ac/Ds transformed lines, excision events were detected by GUS assay and confirmed by PCR and sequence analyses of the excision sites in individual colonies. GUS activity was also demonstrated in the primary regenerants from the Ac/Ds-transformed callus colonies. The method described in this study may be used as an approach for rapid detection of excision events and assessment of various factors limiting Ac/Ds activity in rice cells.

Biolistics↗
PubMed1999

Essential role of transcription factor nuclear factor-kappaB in regulation of interleukin-8 gene expression by nitrite reductase from Pseudomonas aeruginosa in respiratory epithelial cells.

Persistent infection with Pseudomonas aeruginosa increases interleukin-8 (IL-8) levels and causes dense neutrophil infiltrations in the airways of patients with chronic airway diseases. Recently, we have reported that nitrite reductase from P. aeruginosa induces the production of IL-8 in respiratory cells, including bronchial epithelial cells. To determine the molecular mechanism(s) of nitrite reductase-induced IL-8 expression in respiratory cells, A549 epithelial cells were transfected with plasmids containing serial deletions of the 5'-flanking region of the IL-8 gene and then exposed to nitrite reductase. Nitrite reductase significantly enhanced IL-8 gene promoter-driven reporter activity. This increased IL-8 gene expression was inhibited by mutating the nuclear factor-kappaB (NF-kappaB) binding element. Nitrite reductase enhanced nuclear localization of the NF-kappaB binding complex. Furthermore, nitrite reductase induced the degradation of IkappaBalpha, the major cytoplasmic inhibitor of NF-kappaB, and the expression of IkappaBalpha mRNA. These data support the critical role of the activation of NF-kappaB in nitrite reductase-induced IL-8 gene expression in airway epithelium.

DNA-Binding Proteins↗
PubMed1999

Anti-inflammatory drugs and endothelial cell adhesion molecule expression in murine vascular beds.

BACKGROUND: Inflammatory bowel diseases (IBD) are characterised by an intense infiltration of leucocytes that is mediated by adhesion molecules expressed on the surface of activated endothelial cells. AIMS: To determine whether drugs used in the treatment of IBD, specifically dexamethasone (DEX), 5-aminosalicylic acid (5-ASA), methotrexate (MTX), and 6-mercaptopurine (6-MP), alter the expression of endothelial cell adhesion molecules (ECAMs). METHODS: The expression of P-selectin, E-selectin, intercellular adhesion molecule 1 (ICAM-1), and vascular CAM 1 (VCAM-1) in different vascular beds of C57Bl/6J mice was measured using the dual radiolabelled monoclonal antibody technique. RESULTS: Lipopolysaccharide (LPS) elicited a profound increase in the expression of all ECAMs in the mesentery, small intestine, caecum, and distal colon. The LPS induced increase in CAM expression was not significantly affected by prior treatment with either MTX or 6-MP. However, pretreatment with either DEX or 5-ASA significantly attenuated LPS induced increases in expression of P- and E-selectin, and VCAM-1 in the majority of tissues evaluated. DEX also blunted the LPS induced increase in ICAM-1 expression in the caecum and distal colon. DEX, but not 5-ASA, largely abolished the rise in plasma tumour necrosis factor alpha elicited by LPS. CONCLUSIONS: These findings suggest that DEX and 5-ASA may exert their beneficial therapeutic action in IBD, at least in part, by inhibiting the expression of ECAMs which mediate leucocyte adhesion and transmigration in the microvasculature.

Animals↗
PubMed1999

Regulation of tumour necrosis factor (TNF) induced apoptosis by soluble TNF receptors in Helicobacter pylori infection.

BACKGROUND: Tumour necrosis factor (TNF) is a predominant cytokine produced in the gastric mucosa of patients with Helicobacter pylori infection. TNF induces apoptosis in a variety of cells. The soluble TNF receptors (sTNF-Rs) can be divided into sTNF-RI and sTNF-RII, both of which inhibit TNF activity. However, their precise mechanisms remain unclear. AIM: To investigate the role of sTNF-Rs in H pylori infection. METHODS: In 40 patients, production of TNF and sTNF-Rs in gastric mucosa was measured using biopsy specimens. In addition, in gastric epithelial cells, sTNF-R release in response to TNF and the protective effect of sTNF-Rs against the cytotoxic and apoptotic activities of TNF were examined. RESULTS: TNF and sTNF-R expression was significantly higher in H pylori positive than H pylori negative patients. TNF dose-dependently induced sTNF-RI release from gastric epithelial cells. sTNF-RII was also released from the cells. TNF decreased cell viability, but the effect was very small. A combination of anti-sTNF-RI and anti-sTNF-RII monoclonal antibodies significantly increased TNF induced cytotoxicity and apoptosis of gastric epithelial cells. CONCLUSIONS: These results show that sTNF-Rs are actively produced in H pylori infected gastric mucosa. sTNF-Rs appear to protect gastric epithelial cells from TNF induced apoptosis in H pylori infection.

Adult↗
PubMed1999

Variations in the maize Ac transposase transcript level and the Ds excision frequency in transgenic wheat callus lines

To investigate the excision of a maize transposable element in wheat cells, plasmid DNAs containing a Dissociation (Ds) element located between a rice actin 1 gene promoter and a beta-glucuronidase (GUS) gene (gus) were introduced into wheat callus lines by microprojectile bombardment, and transient GUS expression was assayed. The gus-expressing cells after Ds excision were detected only when the Activator (Ac) transposase gene was co-transformed. To further examine a relationship between the amount of Ac mRNA and the Ds excision frequency, the Ds-containing plasmids were introduced into 15 independent transgenic callus lines transformed with the Ac transposase gene. Ten lines expressed the Ac transposase gene under the control of either the cauliflower mosaic virus 35S promoter or the Ac native promoter. The gus gene expression that indicated the Ds excision was observed only in the transgenic callus lines stably expressing the Ac transposase gene. The number of blue spots reflecting the frequency of Ds excision was variable among them. Northern-blot analysis also showed a large variability in the amount of Ac transposase transcripts among the lines. It was however noted that the excision frequency was decreased at a high level of the Ac transposase transcripts, supporting the hypothesis that Ds excision is inhibited above a certain level of the Ac transposase as observed in maize and transgenic tobacco.

Journal Article↗
PubMed1999

Ischemia-reperfusion induced microvascular responses in LDL-receptor -/- mice.

The objective of this study was to determine whether the microvascular responses to ischemia and reperfusion (I/R) are altered in an animal model of atherosclerosis, the low-density lipoprotein-receptor knockout (LDLr -/-) mouse. Intravital video microscopy was used to monitor venular wall shear rate, leukocytes rolling velocity, the number of rolling, adherent and emigrated leukocytes, and albumin leakage in cremasteric postcapillary venules of wild-type (B6129) and LDLr -/- mice exposed to 60 min of ischemia and 60 min of reperfusion. The postcapillary venules of LDLr -/- mice exhibited two- to threefold larger increments in the number of adherent leukocytes and a more profound albumin leakage response to I/R than venules in wild-type mice. The exaggerated inflammatory responses noted in LDLr -/- mice placed on a normal diet were not exacerbated by a high-cholesterol diet. Treatment of LDLr -/- mice with either a platelet-activating factor (PAF) receptor antagonist (WEB-2086) or a monoclonal antibody (YN-1) against the endothelial cell adhesion molecule, intercellular adhesion molecule 1 (ICAM-1), markedly attenuated the I/R-induced leukocyte adherence and albumin leakage. These findings indicate that atherogenic mice are more vulnerable to the deleterious microvascular effects of I/R and that PAF-mediated, ICAM-1-dependent leukocyte adhesion contributes to this exaggerated response to I/R.

Animals↗
PubMed1999

Role of nitric oxide in regulation of renal sympathetic nerve activity during hemorrhage in conscious rats.

The effect of inhibition of nitric oxide (NO) synthesis on the responses of blood pressure (BP), heart rate (HR), and renal sympathetic nerve activity (RSNA) during hemorrhaging was examined with the use of an NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), in conscious rats. In the 0.9% saline group, hemorrhage (10 ml/kg body wt) did not alter BP but significantly increased HR and RSNA by 88 +/- 12 beats/min and 67 +/- 12%, respectively. Intravenous infusion of L-NAME (50 microg. kg(-1). min(-1)) significantly attenuated these tachycardic and sympathoexcitatory responses to hemorrhage (14 +/- 7 beats/min and 26 +/- 12%, respectively). Pretreatment of L-arginine (87 mg/kg) recovered the attenuation of HR and RSNA responses induced by L-NAME (92 +/- 6 beats/min and 64 +/- 10%, respectively). L-NAME by itself did not alter the baroreceptor reflex control of HR and RSNA. Hemorrhage increased the plasma vasopressin concentration, and its increment in the L-NAME-treated group was significantly higher than that in the 0.9% saline group. Pretreatment with the vascular arginine vasopressin V(1)-receptor antagonist OPC-21268 (5 mg/kg) recovered the attenuation of RSNA response induced by L-NAME (54 +/- 7%). These results indicate that NO modulated HR and RSNA responses to hemorrhage but did not directly affect the baroreceptor reflex arch. It can be assumed that NO modulated the baroreflex function by altering the secretion of vasopressin induced by hemorrhage.

Animals↗
PubMed1999

Uptake of 13-hydroperoxylinoleic acid by cultured cells.

Oxidized free fatty acids have profound effects on cultured cells. However, little is known about whether these effects depend on their uptake and metabolism by cells or primarily involve their interaction with cell-surface components. We determined the uptake and metabolism of unoxidized (linoleic or oleic acid) and oxidized linoleic acid (13-hydroperoxyoctadecadienoic acid, 13-HPODE) by endothelial cells, smooth muscle cells, and macrophages. We show that 13-HPODE is poorly taken up by cells. The levels of uptake were dependent on the cell type but were independent of the expression of CD36. 13-HPODE was also poorly used by microsomal lysophosphatidylcholine acyltransferase that is involved in the formation of phosphatidylcholine. Based on these results, we suggest that most of the biological effects of 13-HPODE and other oxidized free fatty acids on cells might involve a direct interaction with cell-surface components. Alternatively, very small amounts of oxidized free fatty acids that enter the cell may have effects, analogous to those of hormones or prostanoids.

Animals↗
PubMed1999

AS-924, a novel orally active bifunctional prodrug of ceftizoxime. Synthesis and relationship between physicochemical properties and oral absorption.

Ceftizoxime (CZX), a parenteral cephalosporin, has potent and broad antibacterial activity. To improve its oral absorption, we synthesized a series of monofunctional and bifunctional prodrugs of CZX. In rabbits, urinary recovery after oral administration of CZX was improved by esterification of the carboxyl group at the C-4 position with various lipophilic moieties (monofunctional prodrugs), and was further increased by introduction of a hydrophilic L-alanine to the amino group on the thiazole ring at the C-7 position (bifunctional prodrugs). Least-squares analysis showed good parabolic correlations between log P and urinary recovery for monofunctional and bifunctional prodrugs, respectively. AS-924, a bifunctional prodrug with a pivaloyloxymethyl and L-alanyl moiety had the best balance of lipophilicity and water-solubility for oral absorption among the prodrugs synthesized.

Administration, Oral↗
PubMed1999

Development of a new analytical method for the electrocardiogram using short-time first Fourier transforms.

To detect the minute electric potential inside the QRS complex, a new frequency domain method was designed using short-time First Fourier Transforms (SFFT) and high-frequency sampling (oversampling). SFFT improved the frequency resolution by oversampling that was applied to this analysis. The electric potential data of 15,000 points received weighted, running average processing and was subtracted from the original waveform to reduce the low-frequency component. The data in a segment of 160 ms, including QRS, was processed by frequency analysis with the SFFT computation routine. The ECG of healthy individuals was analyzed by this method and its usefulness evaluated. The processing waves of the X-axis, Y-axis, and Z-axis of a representative normal subject were formed into 3 groups of peak electric potential. SFFT enabled the detection of the structure inside the QRS complex without signal averaging, and is considered capable of evaluating the process of excitement inside the QRS complex in the various heart diseases.

Adult↗
PubMed1999

Branched-chain amino acid therapy for spinocerebellar degeneration: a pilot clinical crossover trial.

OBJECT: The potential effects of branched-chain amino acids (BCAAs) on spinocerebellar degeneration (SCD) were explored in eleven patients. METHODS: The patients received 200 ml of BCAA-rich solution, 2 mg of thyrotropin-releasing hormone (TRH; protirelin), or a placebo daily for 7 days each in a random order. An SCD score was used to quantify the severity of symptoms. PATIENTS: Eleven patients with SCD (7 male, 4 female; mean age 60+/-11; mean disease duration 5.5 years) participated in this study. RESULTS: The mean SCD score of the eleven patients improved significantly by the BCAA treatment compared with the baseline. The conditions of five of the eleven patients (45%) were clearly improved by the BCAA treatment. All of the responders manifested predominantly cerebellar symptoms, but no prominent parkinsonian symptoms. Two patients with marked rigidity and akinesia did not respond to the treatment. CONCLUSION: We concluded that BCAAs do have a beneficial effect on functional improvement in patients with SCD, and that further large scale studies are needed.

Adult↗
PubMed1999

High-dose chemotherapy with peripheral blood stem cell rescue in blastoid natural killer cell lymphoma.

A 25-year-old man was referred because of skin rash, lymphadenopathy and anemia. Laboratory examinations revealed severe anemia (Hb, 4.8 g/dl) and elevated levels of GOT, GPT, LDH and soluble interleukin-2 receptor. Work-up studies disclosed the involvement of lymphoma cells in lymph nodes, skin, bilateral kidneys and bone marrow. Lymph node biopsy revealed diffuse proliferation of medium- to large-sized lymphoblastic cells. Bone marrow aspiration showed massive infiltration of large blastic cells with no cytoplasmic granules. The lymphoma cells in bone marrow and lymph node showed surface CD3-, cytoplasmic CD3epsilon+, CD4+, CD8-, CD56+, CD57-, CD16- and CD43 (MT-1)+ phenotype. Analyses of T cell receptor beta and gamma genes showed germ line configurations. EBER-1 was not detectable in the lymphoma cells. He was diagnosed as having blastoid natural killer (NK) cell lymphoma. In spite of several courses of combination chemotherapy, the lymphoma was progressive. He was then treated with high-dose chemotherapy and peripheral blood stem cell rescue, achieving remission which has now lasted for more than 12 months. We consider that blastoid NK cell lymphoma is an extremely aggressive subtype of CD56-positive lymphomas, and high-dose chemotherapy with peripheral blood stem cell rescue should be included for the choice of the treatment.

Adult↗
PubMed1999

CD4- and CD56-positive T-cell line, MTA, established from natural killer-like T-cell leukemia/lymphoma.

We have established a T-cell line, MTA, from the peripheral blasts of a patient with natural killer (NK)-like T-cell leukemia/lymphoma. The MTA cell displays a T-cell and NK-cell phenotype (CD2+, CD3+, CD4+, CD56+) identical to freshly isolated leukemic blasts from the patient. This cell line shows clonal T-cell receptor rearrangement and a distinguishable character by light microscopy with May-Grünwald Giemsa staining. G-banding analysis showed that the MTA cells had a karyotype of 94(4N), XXXX, add (1) (p36), del (5) (q14q23), add (17) (p11), add (19) (q13). However, unlike NK malignancy, we could not show a direct pathogenic role for Epstein-Barr virus (EBV) with EBV-encoded small RNA and polymerase chain reaction analysis. The MTA cell line is a novel cell line with which to study NK-like T-cell ontogenecity.

CD4 Antigens↗