Search PubMed⌕ Search

Biomedical subjects

Y Niwa

Publications and source records attributed to Y Niwa.

At least 145 records · Page 8Linked to original sources
PubMed1994

Close co-localization of CD4 and a serine esterase tryptase TL2 on the cell-surface of human monocytoid and CD4+ lymphoid cells.

Tryptase TL2, a serine esterase in the membrane of human monocytoid and CD4+ lymphoid cells, specifically binds to the V3 domain of HIV-1 gp120. Here we report that monoclonal antibodies against CD4 that recognize the epitope interacting with gp120 specifically blocked the immunostaining of cell-surface tryptase TL2, although the antibody does not cross-react with tryptase TL2. Down-regulation of cell-surface CD4 induced by HIV-1 Nef prevented this blocking effect. These data suggest that CD4 is closely co-localized with tryptase TL2 on the cell surface and that regulation of the expression of tryptase TL2 is not associated with that of CD4.

Antibodies, Monoclonal↗
PubMed1994

A proposed staging system for primary gastric lymphoma.

BACKGROUND: Although primary gastric lymphoma is the most common extranodal lymphoma, no specific staging system exists. METHODS: The authors reviewed 98 cases histologically classified according to the Working Formulation, including low grade B-cell lymphoma of mucosa-associated lymphoid tissue type. Survival rates were calculated by the Kaplan-Meier method according to T, N, and M of the general rules of the International Union Against Cancer TNM system. The definitions of these categories are as follows: T1, tumor invades the lamina propria or submucosa; T2, the muscularis propria; T3, the subserosa; T4, the serosa without invasion of adjacent structures; T5, adjacent structures; N0, no regional lymph node metastasis; N1, perigastric lymph nodes within 3 cm of the edge of the primary tumor; N2, perigastric lymph nodes more than 3 cm from the edge of the primary tumor or in lymph nodes along the left gastric, common hepatic, splenic, or celiac arteries; N3, paraaortic and hepatoduodenal lymph nodes and/or other intraabdominal lymph nodes; N4, beyond N3; M0, no distant metastasis; and M1, positive. RESULTS: The overall 5-year survival rate was 83.5%; it was 100% in T1, 82.4% in T2, 84.2% in T3, 52.9% in T4, and 33.3% in T5; 93.9% in N0, 90.5% in N1, 66.2% in N2, and 44.4% in N3/N4; and 86.0% in M0 and 25.0% in M1. Based on these results, the authors proposed a new staging system as follows: Stage I, T1/N0, N1/M0; Stage II, T1/N2/M0, T2,T3/N0,N1,N2/M0; Stage III, T4,T5/any N/M0, any T/N3, N4/M0; and Stage IV, any T/any N/M1. According to this system, the 5-year survival rate significantly decreased as the stage progressed: 100% in Stage I, 88.9% in Stage II, 52.1% in Stage III, and 25.0% in Stage IV. In Stages I and II, survival rates were not significantly different whether chemotherapy was done or not, whereas in Stage III all patients treated with surgery alone died. CONCLUSIONS: This staging system is useful for assessing prognosis of and deciding a therapeutic plan for primary gastric lymphoma.

Adult↗
PubMed1994

Detection of alpha-fetoprotein mRNA, an indicator of hematogenous spreading hepatocellular carcinoma, in the circulation: a possible predictor of metastatic hepatocellular carcinoma.

We attempted to detect circulating hepatocellular carcinoma by demonstrating hepatocyte-associated mRNA in the nuclear cell component of peripheral blood using nested reverse transcription-polymerase chain reaction because of the extremely small number of tumor cells in the circulation. Albumin mRNA was demonstrated not only in the liver tissue (hepatocytes) and HepG2 cells but also in nuclear cells of the blood from normal healthy volunteers (neutrophils and lymphocytes) by reverse transcription-polymerase chain reaction. In contrast, alpha-fetoprotein mRNA was demonstrated in the liver tissue, as well as in HepG2 cells, but not in peripheral blood of normal healthy volunteers, indicating the possibility of using alpha-fetoprotein mRNA for detection of benign and malignant hepatocytes among the population of neutrophils and lymphocytes. alpha-Fetoprotein mRNA in peripheral blood was detected in 17 of 33 cases of hepatocellular carcinoma (52%), 2 of 13 cases of cirrhosis (15%) and 2 of 17 cases of chronic hepatitis (12%). alpha-Fetoprotein mRNA was not demonstrated in 26 cases of normal healthy volunteers (0%). Among the patients with hepatocellular carcinoma, total volume of tumor tissue, maximum size of tumor and serum alpha-fetoprotein level were markedly increased in the patients with alpha-fetoprotein mRNA in blood. In addition, alpha-fetoprotein mRNA was detected in the blood of all 6 patients showing metastasis at extrahepatic organs (100%), in contrast to 11 of 27 cases without metastasis (41%). From these results, we conclude that the presence of alpha-fetoprotein mRNA in peripheral blood may be an indicator of circulating malignant or benign hepatocytes, which might predict hematogenous spreading metastasis of tumor cells in patients with hepatocellular carcinoma.

Adult↗
PubMed1994

Role of polymorphonuclear leukocytes in galactosamine hepatitis: mechanism of adherence to hepatic endothelial cells.

To investigate the role of polymorphonuclear leukocytes in galactosamine-induced hepatic injury, we injected rats intraperitoneally with antiserum against rat polymorphonuclear leukocytes to deplete circulating neutrophils, then administered galactosamine plus lipopolysaccharide. Polymorphonuclear leukocytes in the hepatic sinusoids were increased after administration of galactosamine plus lipopolysaccharide, whereas pretreatment with the antiserum decreased the number of circulating leukocytes and reduced the mortality and the severity of hepatic injury. Serum collected 1 hr after galactosamine/lipopolysaccharide treatment enhanced in vitro polymorphonuclear leukocyte adherence to hepatic endothelial cells and induced leukocyte superoxide production. Intercellular adhesion molecule-1 expression on hepatic endothelial cells was also enhanced after stimulation with the serum. Polymorphonuclear leukocyte adhesion was partially inhibited by an antibody against tumor necrosis factor-alpha but not by superoxide dismutase. These results suggest that polymorphonuclear leukocytes play an important role in galactosamine-induced hepatic injury and that the accumulation and activation of leukocytes, as well as the enhanced expression of adhesion molecules on hepatic endothelial cells, can be induced by biologically active mediators such as tumor necrosis factor-alpha. In addition, prostaglandins E1 and E2 lessened the enhanced adherence of polymorphonuclear leukocytes and thus contributed to protection against hepatic injury.

Alprostadil↗
PubMed1994

Role of Coulomb energy in promoting collisionally activated dissociation of multiply charged peptides formed by electrospray ionization.

Electrospray ionization tandem quadrupole mass spectrometry has been applied to a series of lysine-substituted octaalanines and some naturally occurring peptides containing more than two basic amino acid residues. Unusually high fragmentation efficiency along with site-specific cleavages at the outer side of and remote from basic residues were observed for collisionally activated dissociation spectra of multiply charged peptides (MCP) with basic residues in close proximity. It was suggested that Coulomb energy (CE) rather than Coulomb repulsion (CR) was responsible for promoting fragmentation of the MCP studied. A possible fragmentation mechanism of MCP is proposed, in which the conversion of CE into internal vibrational energy was brought about by intramolecular proton migration in the presence of CR between charged sites.

Amino Acid Sequence↗
PubMed1994

Long-term follow-up study of changes in lipid peroxide levels and the activity of superoxide dismutase, catalase and glutathione peroxidase in mouse skin after acute and chronic UV irradiation.

Lipid peroxide levels, the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px), and the development of tanning in the skin of C57 BL/6 mice were assessed for long periods, from very early to late stages, after acute or chronic UVB irradiation. Acute UVB irradiation produced an increase in lipid peroxide levels that peaked 18 h after irradiation, after which the levels declined to a minimum 2-3 days after irradiation and then gradually rose to baseline. Chronic irradiation caused the lipid peroxide level to fall to a minimum at 0.5-1.0 weeks, after which it gradually returned to baseline by the third week. SOD and GSH-Px activities decreased sharply after acute irradiation, reaching a minimum 18 h after irradiation. Following chronic irradiation, these enzyme levels peaked after 0.5 weeks, and thereafter declined gradually to the original levels 3 weeks after irradiation. In contrast, catalase activity did not change significantly. Tanning began to increase at 1.5 weeks after irradiation, with an accelerated rate of increase from the third week.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effect of anti-allergic agents on chemotaxis of neutrophils by stimulation of chemotactic factor released from hepatocytes exposed to ethanol.

In an attempt to clarify a mechanism of neutrophil infiltration in the liver of alcoholics and possible therapeutic effect of antiallergic agents on accumulation of these cells in the liver, we investigated chemotaxis of neutrophils by stimulation of a chemotactic factor released from rat hepatocytes exposed to ethanol. When hepatocytes were incubated with more than 30 mM ethanol for 24 hr, chemotactic activity for both rat and human neutrophils was demonstrated in the conditioned medium. An enhanced chemotactic activity of the conditioned medium was reduced in the presence of antibody against KC/gro protein, one of the interleukin-8-related cytokines in rodents. Antiallergic agents such as azelastine or ketotifen at a concentration of > 0.01 microM markedly reduced chemotaxis of neutrophils. Prednisolone at a concentration of > 10 microM also reduced chemotaxis of neutrophils. These results suggest that neutrophil accumulation in the liver of human alcoholics could be induced by a chemotactic factor produced by the ethanol-treated hepatocytes and that antiallergic agents could be effective against the extent of alcoholic hepatitis by reducing chemotaxis of neutrophils.

Adult↗
PubMed1994

Churg-Strauss syndrome (allergic granulomatous angiitis) with multiple perforating ulcers of the small intestine, multiple ulcers of the colon, and mononeuritis multiplex.

A case of Churg-Strauss syndrome with multiple perforations of the small intestine is described. A 31-year-old woman was admitted with a complaint of epigastric pain. She had a history of bronchial asthma. One week before admission, white blood cell count was 20,800/mm3 with 59% eosinophils. Neurological examination on admission disclosed mononeuritis multiplex with paresthesia in both the lower and upper extremities. At colonoscopy, there were scattered aphthous ulcers in the colon. Ophthalmological examination revealed allergic conjunctivitis. After admission, hypereosinophilia increased to as high as 36,000/mm3. Oral administration of prednisolone (60 mg/day) was begun. On the 3rd day of the treatment, the eosinophil count decreased dramatically, to 400/mm3, while severe abdominal pain developed. Since abdominal X-ray film revealed free air in the abdominal cavity, emergency laparotomy was performed and multiple intestinal ulcers with perforations were found. Partial ileectomy was performed. Pathological findings of the resected specimen were interpreted as a necrotizing angiitis with extravascular granuloma. Since the operation, the patient has been asymptomatic, except for neurological symptoms. Hypereosinophilia has decreased without treatment to counts averaging 270/mm3, within 3 months. On the basis of the clinical features and histopathological findings, a diagnosis of Churg-Strauss syndrome was established.

Adult↗
PubMed1994

A case of primary gastric choriocarcinoma and a review of the Japanese literature.

A 63-year old woman who had experienced melena for 2 weeks was admitted to Tokyo University Hospital. Gastric adenocarcinoma was diagnosed endoscopically and histologically, and a total gastrectomy was performed soon thereafter. Pathological examination of the resected stomach revealed choriocarcinoma of the stomach. Although chemotherapy was administered after surgery, she died 3 months after admission. Autopsy confirmed the diagnosis of primary gastric choriocarcinoma, a rare, but highly malignant tumor. It is characteristic; macroscopically it forms a necrotic mass with bleeding, and microscopically it often consists of adenocarcinoma and choriocarcinoma. Since its prognosis is extremely poor, we must take into account the possibility of primary gastric choriocarcinoma when a hemorrhagic gastric tumor with necrosis is found.

Aged↗
PubMed1994

Inhibitory effect of prostaglandin E1 on human neutrophil function.

Neutrophils accumulated in the lung are thought to play a pivotal role in the pathogenesis of host auto-injury such as adult respiratory distress syndrome (ARDS). We investigated the effect of prostaglandin E1 (PGE1) on several aspects of human neutrophil function. PGE1 significantly decreased reactive oxygen species (ROS), (O2-, H2O2, OH.) generation by neutrophils as well as neutrophil phagocytosis and chemotaxis. In contrast, the drug did not affect the levels of ROS generated by a cell-free ROS generating system. In addition, intracellular calcium concentrations ([Ca2+]i) in neutrophils stimulated by f-Met-Leu-Phe were decreased in the presence of PGE1. These data suggest that the reduction in ROS production and neutrophil phagocytosis and chemotaxis by PGE1 may contribute to the effectiveness of the drug in host auto-injury including ARDS. The suppression of the increase in [Ca2+]i may at least be responsible for inhibition of these neutrophil functions by PGE1.

Adult↗
PubMed1994

Organ-specific and auxin-inducible expression of two tobacco par A-related genes in transgenic plants.

We have isolated four genomic DNA clones that contain the transcription initiation site of the parA gene(s) from a tobacco genomic library by hybridization with the 5' segment of the parA cDNA previously isolated. They were classified into two types on the basis of their nucleotide sequences. Southern blot analysis indicated that two types of clones were respectively derived from the two parental species of tobacco, Nicotiana tomentosiformis and Nicotiana sylvestris. The genes corresponding to these clones were designated as parAt and parAs, respectively, and the parA cDNA clone was shown to code for mRNA from parAt on the basis of its nucleotide sequence. The 5' regions about 400 nucleotides upstream from the transcription initiation sites of the parAt and parAs genomic clones were highly homologous to one another, but regions further upstream showed no significant similarity. The coding sequence of the GUS (beta-glucuronidase) reporter gene was linked to the 5'-upstream regions of parAt and parAs, and the sites of expression of these fusion genes were examined in transgenic tobacco plants. In the absence of auxins, both fusion genes were expressed in capsules at a late stage of seed development, mature seeds, a root apex and a root-hair zone whereas no significant expression was seen in other organs. Their expression was enhanced by 2,4-dichlorophenoxyacetic acid in most of the organs of tobacco. The results show that expression of these genes is regulated by both organ-specific and auxin-inducible mechanisms.

Amino Acid Sequence↗
PubMed1994

Establishment of new inbred strains derived from Japanese wild rats (Rattus norvegicus).

Inbreeding of Japanese wild rats (Rattus norvegicus) resulted in five new strains. The conception rates of wild rat strains were lower than those of inbred laboratory strains, and maternal aggressiveness was observed in some wild strains. The body size of domesticated animals was larger than that of captured ancestors. Two strains have been established as inbred strains; the MITA strain has been tamed to the level of laboratory rats, while the nature of the MITD strain is wild. The MITB strain was derived from the MITA strain as a coat color variant. The MITC and MITE strains have been bred to the F15 and F11 generations, respectively. The new strains can provide new genetic variations against a wild type background and might be useful for physiological and psychological experiments.

Animals↗
PubMed1994

Sequential observation of gastric ulcer healing by endoscopic ultrasonography.

BACKGROUND: The relationship between superficial findings and the inner structure of gastric ulcers is unclear. The present study was undertaken to clarify the relationship between them. METHODS: In the first study, 43 patients with active gastric ulcers were examined by endoscopic ultrasonography (EUS) in each stage of Sakita's endoscopic classification. In the second study, 16 patients with gastric ulcer scars were examined by EUS in both S1 stage and S2 stage. RESULTS: Ulcer area, ulcer length, thickness of the ulcer base, and diameter of the crater differed significantly in each endoscopic stage. Ulcer area, ulcer length, and thickness of the ulcer base differed significantly even between S1 stage and S2 stage. Mean ulcer area in S1 stage was 96.9 mm2; this shows that the ulcer scar in S1 stage is incomplete with regard to tissue contraction. Although ulcer area in S2 stage had shrunk significantly compared with that in S1 stage, it still remained 53.3 mm2. This implies that the risk of local recurrence remains even in S2 stage. CONCLUSIONS: Sequential observation by EUS showed that the healing of the ulcer surface strongly reflected the healing within the ulcers.

Adult↗
PubMed1994

Abnormalities in serum lipids and leukocyte superoxide dismutase and associated cataract formation in patients with atopic dermatitis.

BACKGROUND AND DESIGN: Because lipid peroxides are believed to play a role in cataract formation, we examined serum lipid and lipid peroxide levels in patients with atopic dermatitis (AD) complicated by cataract formation in comparison with AD patients without cataracts and patients with other forms of dermatitis, taking into account any treatment with corticosteroids. Since reactive oxygen species play an important role in lipid peroxide formation, the induction of leukocyte superoxide dismutase, which scavenges reactive oxygen species and inhibits lipid peroxidation, was also examined. Most of the patients with AD and cataract were older than 13 years, and had severe, treatment-resistant dermatitis. RESULTS: Serum levels of chylomicrons, very-low-density lipoprotein, and lipid peroxide levels were increased, and superoxide dismutase activity was markedly less inducible in patients with cataracts. These abnormalities demonstrated were irrespective of previous topical corticoid treatment. Although AD patients without cataracts also showed significant abnormalities in all of the parameters measured, these were less marked than in the AD patients with cataracts. In contrast, these findings were not observed in patients with other forms of dermatitis who had been receiving prolonged topical corticosteroid therapy. CONCLUSIONS: High levels of serum lipids and decreased superoxide dismutase inducibility thus appear to be correlated with AD and also independently with attendant cataract formation. From the observation that most of the patients originated from areas of high environmental pollution whose products are known to produce great amounts of reactive oxygen species, excessive lipid peroxide formation, perhaps in part environmentally induced, seems to correlate to severe, adult-type AD with cataract formation.

Adolescent↗
PubMed1994

[The relationship between titrated acidity (mEq/l) and pH of human gastric juice: a study based on the data estimated by pH-meter].

The relationship between titrated acidity and pH was studied using the 3206 samples of human gastric juice, which were collected by the intragastric tube in the basal and gastrin stimulated conditions. The pH of samples subjected to the present study ranged from 0.95 and 6.9. The results showed that a certain value of pH did not always indicate an identical value of titrated acidity, and that the coefficient of variation was greater as pH value rose. As a whole, however, the acidity became lower with the increase of pH value. Thus, the relationship between pH and titrated acidity could be expressed closely as "Y = 369.19 - 424.09X + 203.66X2 - 48.29X3 + 5.57X4 - 0.25X5), where X = pH and Y = acidity. The conversion table from pH to acidity, which was calculated by this expression, was presented for the clinical use.

Adult↗
PubMed1994

Superficial esophageal carcinoma: evaluation by endoscopic ultrasonography.

OBJECTIVES: The aim of this study was to evaluate the usefulness of endoscopic ultrasonography (EUS) in the staging of superficial esophageal carcinoma (SEC). METHODS: We examined the histopathologic findings of 28 patients with SEC which was confirmed in the postoperative histologic evaluation. The EUS results preoperatively estimated were compared with them. RESULTS: There were nine patients with mucosal carcinoma (two intraepithelial carcinomas and seven carcinomas limited to the mucosal layer) and 19 patients with submucosal carcinoma. The mucosal carcinomas revealed no lymph node metastasis or vessel permeation, whereas the submucosal carcinomas revealed lymph node metastasis (71%) and vessel permeation (lymphatic, 58%, vascular, 21%). The accuracy rates of depth of invasion by EUS were mucosa, 67% (6/9); submucosa, 79% (15/19); and total, 75% (21/28). EUS could not detect microinvasion to the submucosa. The overall accuracy rate of EUS in the evaluation of periesophagogastric lymph node metastasis was 72%: sensitivity 58% and specificity 85%. CONCLUSIONS: It has been clinically proved important to differentiate mucosal carcinoma from submucosal carcinoma in the staging of SEC, and EUS is recommended in differentiating between them.

Adult↗
PubMed1993

Increased release of KC/gro protein, intercrine cytokine family, from hepatocytes of the chronically ethanol fed rats.

In an attempt to clarify the mechanisms of neutrophil-accumulation in the liver of alcoholics, release of KC/gro protein (intercrine cytokine family) from hepatocytes in the chronically ethanol fed rats was examined. Chemotactic activity for rat neutrophils was demonstrated in the culture supernatant of hepatocytes isolated from the ethanol fed rats, which was then inhibited in the presence of antibody against rat KC/gro protein. Immunoblot analysis revealed that the peptide reacted with antiserum against KC/gro protein was demonstrated at a molecular weight of 20-23kDa, and an amount of KC/gro protein released from the hepatocytes of the chronically ethanol fed rats was increased, as compared with that of the control rats.

Alcoholism↗