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Biomedical subjects

K Amano

Publications and source records attributed to K Amano.

At least 127 records · Page 7Linked to original sources

Helicobacter pylori induces proinflammatory cytokines and major histocompatibility complex class II antigen in mouse gastric epithelial cells.

Although Helicobacter pylori has been reported to stimulate the release of various cytokines from gastric tissue, it remains unknown whether normal and nontumorous gastric epithelial cells produce these cytokines. Therefore, in this study, we used a normal mouse gastric surface mucous cell line (GSM06) to determine whether gastric epithelial cells produce proinflammatory cytokines in response to H. pylori. The expression of MHC class II antigen was also examined, to investigate whether gastric epithelial cells participate in the immune response to H. pylori. In the study, GSM06 cells were incubated with H. pylori or its lipopolysaccharide (LPS). Proinflammatory cytokines were detected by Northern and Western blot analysis. The expression of MHC class II antigen was examined by fluorescence activated cell sorter (FACS) analysis. Genetic expression of proinflammatory cytokines such as interleukin-1alpha, tumor necrosis factor-alpha, and cytokine-induced neutrophil chemoattractant-2beta was enhanced by both intact and sonicated H. pylori, but not by H. pylori LPS. The expression of MHC class II antigen was induced by H. pylori more strongly than by interferon-gamma. We conclude that H. pylori induces the expression of proinflammatory cytokines and MHC class II antigen in gastric epithelial cells. Gastric epithelial cells may act as antigen-presenting cells and participate in the immune response to H. pylori infection.

Animals↗

Should C-section be applied to fetal arrhythmia?

OBJECTIVE: To investigate the efficacy of fetal arterial oxygen saturation (SpO2) monitoring in cases of fetal arrhythmia. STUDY DESIGN: Continuous fetal SpO2 was obtained by infrared pulse oximetry (Nellcor Puritan Bennett Inc.). The relationship between SpO2 and FHR pattern was studied in 47 cases. Then three cases of congenital complete A-V block and two cases of supraventricular tachyarrhythmia were prospectively managed by SpO2 monitoring during labor. RESULTS: Whenever the FHR was reassuring, the range of SpO2 was stable between 40 and 80%. Although a variation in SpO2 values were noted during decelerative patterns, a more acidotic tendency was found in cases where SpO2 was below 40% prior to delivery. SpO2 values of all five cases of fetal arrhythmia were stable between 40 and 80% and safe vaginal delivery proved to be possible. CONCLUSIONS: Fetal SpO2 monitoring seemed to be a useful method to evaluate fetal oxygenation during labor in cases of fetal arrhythmia.

Adult↗

Reduced protein tyrosine phosphatase (PTPase) activity of CD45 on peripheral blood lymphocytes in patients with systemic lupus erythematosus (SLE).

To disclose the mechanism of aberrant function of peripheral blood lymphocytes (PBL) in SLE, we focused on the catalytic function of CD45, and determined the CD45 PTPase activity in SLE patients. The sample population consisted of 32 SLE patients with different disease activity. PTPase activity of cell lysates immunoprecipitated by anti-CD45 MoAb was assayed against phosphotyrosine analogue PNPP, followed by measuring the release of para-nitro phenol at 410 nm. CD45 PTPase activity of PBL was significantly decreased in SLE patients, compared with that of normal controls and patients with systemic sclerosis (964 +/- 265, 1202 +/- 172, 1210 +/- 125, respectively; SLE versus normal, P<0.05). It was correlated with SLE Disease Activity Index (SLEDAI) score (r = 0.597, P = 0.0006), but not with the dose of prednisolone (r = 0.214, P = 0.2657), indicating that CD45 PTPase activity became reduced when the disease was active, but it was not affected by prednisolone. Moreover, it was not corrected by in vitro culture with or without stimulation. The expression of CD45 on PBL was comparable between normal and SLE, raising a possibility that it may be due to aberrant regulation of catalytic function of CD45 in SLE. Given the evidence that tyrosine phosphorylation of cellular proteins by tyrosine kinases and phosphatases is one of the key biochemical events in the signal transduction pathway, the decreased CD45 PTPase activity in SLE may account for the defective signal transduction via TCR/CD3, leading to dysregulated effector function of the lymphocytes.

Adult↗

Gingival crevicular interleukin-1 and interleukin-1 receptor antagonist levels in periodontally healthy and diseased sites.

Interleukin-1 (IL-1) molecules, IL-1 alpha and IL-1 beta are cytokines involved in the acute-phase response against infection and in the pathogenesis of periodontal destruction. Administration of exogenous IL-1 receptor antagonist (IL-1ra) is effective in reducing the inflammatory reactions mediated by IL-1. However, the relationship between these three naturally occurring IL-1 molecules and periodontal diseases has been poorly characterized. We investigated the correlation of gingival crevicular IL-1 molecules and the clinical status of patients with different severities of periodontitis. IL-1 alpha, IL-1 beta, IL-1ra and the total IL-1/IL-1ra ratio (IL-1 activity index; IL-1AI) were measured in 75 gingival crevicular fluid (GCF) samples from non-inflamed gingiva sites in 2 healthy subjects and diseased sites in 7 patients with several types of periodontitis. IL-1 alpha, IL-1 beta and IL-1ra were measured by specific non-cross-reactive enzyme linked immunosorbent assay. The probing depth, gingival index and alveolar bone loss of each site was recorded at the time of GCF sampling. The total amount of IL-1 alpha, IL-1 beta and the IL-1AI, but not total IL-1ra, were found to be correlated with alveolar bone loss score. Three IL-1 molecules were also measured in the gingival tissue of patients with periodontitis. A similar progressive decrease of the IL-1AI was detected in gingival tissue with periodontitis. These results suggest that the amounts of both crevicular IL-1 and IL-1AI are closely associated with periodontal disease severity.

Acute-Phase Reaction↗

Leukocytapheresis with leukocyte removal filter as new therapy for ulcerative colitis.

Leukocytapheresis (LCAP) with a leukocyte removal filter column was administered for 45 patients with ulcerative colitis (UC). We evaluated changes in the leukocyte count and the differential percentages during LCAP. Cytokine production was assessed from each patient's peripheral mononuclear cells or monocytes. Flow cytometry was performed to assess the removal rates of activated cells and adhesion molecule positive cells by LCAP. Clinical improvement was recognized in 35 of 45 patients during intensive LCAP therapy, and it continued throughout maintenance therapy in 32 patients (71.1%). The leukocyte count was decreased to about 40% during the first 30 min, but it increased to approximately 170% at 20 min after the completion of LCAP. The concentration of tumor necrosis factor (TNF)alpha before LCAP in the effective group was higher than it was in either the ineffective group or the control group. Its level decreased to near normal range after LCAP. In the effective group, the concentrations of interleukin (IL)-1beta, IL-2, interferon (IFN)gamma, and IL-8 were near the normal upper limits before LCAP; however, they had decreased after LCAP. The concentration of IL-4 increased after LCAP. In the ineffective group, in contrast, the concentrations had been at or near normal before the initial LCAP treatment. Flow cytometry study revealed that LCAP could remove the activated cells and adhesion molecule positive cells more effectively. The clinical improvement and the changes observed before and after LCAP therapy suggest that LCAP is able to intervene in the causal mechanism(s) of UC.

Blood Cell Count↗

Reactivities of Lewis antigen monoclonal antibodies with the lipopolysaccharides of Helicobacter pylori strains isolated from patients with gastroduodenal diseases in Japan.

We have examined the reactivity of monoclonal antibodies (MAbs) specific for Lewis antigens (Le(x), Le(y), Le(a), and Le(b)) with Helicobacter pylori lipopolysaccharides (LPS) by immunoblot analysis and enzyme-linked immunosorbent assay (ELISA). Sixty-eight strains of H. pylori were isolated from patients with chronic gastritis, gastric and duodenal ulcers, and gastric cancer in Japan. The cells were treated with proteinase K, and the resulting fractions were used as a source of LPS for the immunoassays. In the immunoblot analysis, 28 isolates (41%) and 29 isolates (42%) reacted with anti-Le(x) and anti-Le(y) MAbs, respectively, while 4 isolates (6%) and 7 isolates (10%) reacted with anti-Le(a) and anti-Le(b) MAbs. On the other hand, in ELISA, the number of isolates that reacted with anti-Le(x) MAbs fell significantly to 21 isolates (30%) but the number of isolates that reacted with the other anti-Lewis antigen MAbs remained relatively unchanged. These data show that the immunoblotting technique is more sensitive than the ELISA technique for the detection of immunocomplexes of anti-Le(x) MAbs and components of H. pylori LPS. Furthermore, human serum was found to react with the synthetic Lewis antigens regardless of the status of the individual's H. pylori infection. This means that humans may naturally possess antibodies against Lewis antigens in the absence of H. pylori infection.

Antibodies, Monoclonal↗

Low antigenicity of the polysaccharide region of Helicobacter pylori lipopolysaccharides derived from tumors of patients with gastric cancer.

We have examined the antibody response to Helicobacter pylori lipopolysaccharide (LPS) during natural infection in humans. The sera of over 70% of H. pylori-infected individuals were found to contain immunoglobulin G antibodies against the LPS fractions isolated from smooth strains of H. pylori but not against those derived from rough strains, as determined by enzyme-linked immunosorbent assay. These results taken together with the immunoblot data indicated that the polysaccharide region of H. pylori LPS is antigenic in humans. However, the antigenicity of the polysaccharide varied, depending on the strain. We found that smooth H. pylori strains isolated from the tumors of patients with gastric cancer showed significantly lower antigenicity than smooth strains derived from patients with chronic gastritis and gastric and duodenal ulcers. The results suggest that the levels of antigenicity of the polysaccharide region of H. pylori LPS in humans correlate with the nature of the gastroduodenal diseases and that they allow a particular distinction to be made between gastric cancer and other gastroduodenal diseases, especially chronic gastritis.

Adult↗

Is stereotactic surgical treatment still necessary for Parkinson's disease in the contemporary trend of medical therapy with dopamine receptor agonist?

Clinical experience with the use of pergolide is presented in 55 patients with Parkinson's disease. Fifty to 900 micrograms/day (mean 242.73, SD 217.51) of pergolide and 0.64-17.05 micrograms/kg/day (mean 4.58, SD 4.25) pergolide was given together with L-carbidopa to 29 males and 26 females for a period of up to 2 years 7 months. Low-dose pergolide together with L-carbidopa is effective in the treatment of parkinsonism without side effects, even in advanced stages of the disease. No patients required surgical treatment such as pallidotomy or deep brain stimulation recommended by other investigators. We emphasize that parkinsonism can be sufficiently treated with pergolide and L-dopa and that surgical treatment should be minimized unless there is no alternative.

Aged↗

CP2289, a new 5-HT3 receptor ligand: agonistic activities on gastroenteric motility.

A new 5-HT3 receptor ligand, CP2289, was synthesized and pharmacologically tested. Although CP2289 inhibited the Bezold-Jarisch reflex, it contracted the excised ileal muscle of mice, rats and guinea pigs. This response may reflect a partial agonist character of CP2289 in the gut. In vivo antiemetic and gastric emptying tests gave similar results.

Animals↗

[Clinical study of patients with positive reactions in patch tests with local anesthetics].

Local anesthetics have been contained in various OTC drugs and the number of cases of allergic contact dermatitis due to local anesthetics has increased recently. Thirty-five hundreds and fourteen cases suspected of suffering from drug eruption or contact dermatitis were the subjects of this study during the 8 years from January, 1988 to December, 1995. One hundred and thirty-eight cases, suspected of having allergic contact dermatitis were patch tested with topical medicaments including local anesthetics and 70 (50.7%) of them showed positive. In 49 of the 60 cases who reacted positively to anesthetics extensive patch tests with the individual ingredients of the products were carried out. The local anesthetics causing positive reactions were as follows (in order of frequency): dibucaine hydrochloride (35 cases: 71.4%), ethyl aminobenzoate (12 cases: 24.5%), lidocaine hydrochloride (2 cases: 4.1%), and procaine hydrochloride (1 case: 2.0%). The number of patients displaying allergies to local anesthetics has increased, especially cases caused by dibucaine hydrochloride. And the total positive reaction rate to dibucaine hydrochloride in the patch tests was 3.7%, which was as high that to the well-known strong sensitizer PPDA (3.9%) and neomycin (2.9%). Forty-three cases sensitive to local anesthetics were also studied for cross-sensitivity.

Anesthetics, Local↗

[Remission by leukocytapheresis for a patient with ulcerative colitis found refractory by conventional drug therapies].

A 40-year-old male was admitted to our hospital on August 30, 1994 to receive a new ulcerative colitis (UC) therapy, leukocytapheresis (LCAP). On the admission day, he had bloody stool 5 to 6 times/day, abdominal pain, slight fever, and hypoproteinemia. His UC type was moderately severe left-sided colitis with pseudopolyposis. Prior to admission to our hospital, his condition had not improved for about 9 months, despite drug therapies such as salicylazosulphapyridine, intravenous high dose prednisolone, protease inhibitor, intraarterial hydrocortisone sodium succinate, 4 series of pulse therapies with metylpredonisolone, enema of corticosteroid, azathioprine (Imuran), and cyclosporine at another hospital. Thus he was introduced to our college hospital and treated by LCAP since September 1. After 10 LCAP sessions, remission was observed and the patient discharged on December 23. Until he was later operated on for heavy bleeding after he had discontinued treatment and had drunk heavily, he had maintained remission for 13 months with LCAP only once a month even after we gradually decreased the other medical supports and stopped all of them. After LCAP, the normalization of high percentage of leukocytes presented HLADR+ and lymphocytes presented CD 11 a+ CD 8+ was also observed. This suggests LCAP intercepts the excess immune reaction in UC by removing leukocytes.

Adult↗

[An adult case of dermatomyositis complicated with cecum perforation and panniculitis].

The case of dermatomyositis complicated with cecum perforation and panniculitis occurred in a 62-year-old woman was reported. She was admitted to Keio University Hospital with a history of proximal muscular weakness, and dysphagia. Physical examination showed erythema over the face and shoulder. Serum level of muscle enzymes was remarkably increased. The diagnosis of dermatomyositis was made based on proximal muscular weakness, elevated serum level of muscle enzymes and myogenic change of electromyocardiogram. The treatment with 60 mg/day of prednisolone was started, and was a good response. However, 7 months later the disease became active again when the amount of prednisolone was reduced to 13 mg/day. Subsequently she complained of abdominal pain on the right lower quadrant. The surgical findings included peritonitis due to the perforation of the cecum and multiple ulcers of the cecum. After operation, azathioprine was added. Four years and 9 months later, she noticed skin erythema with ulceration and subcutaneous nodule. Skin biopsy indicated the findings of the panniculitis with membrano-cystic lesion. It was thought that both cecum perforation and panniculitis were caused by angiopathy which was often seen in childhood dermatomyositis.

Cecal Diseases↗

Helicobacter pylori infection accelerates gene expression of glicentin in the gastric mucosa. Its association with intestinal metaplasia of the stomach.

BACKGROUND: Glicentin is an intestinal polypeptide hormone which seems to promote intestinal metaplasia (IM) in the gastric mucosa. The aim of this study was to clarify whether Helicobacter pylori infection accelerates glicentin gene expression. METHOD: Glicentin mRNA was investigated by reverse-transcription polymerase chain reaction using gastric biopsies from 47 patients examined endoscopically and denying IM. RESULTS: IM was observed in 18 (38.3%) cases histologically, but not in the other 29 (62.7%). Glicentin mRNA was significantly correlated with histological IM (P < 0.01) and was positively correlated with H. pylori infection (P < 0.05). CONCLUSION: Our results indicate that H. pylori infection is associated with the induction of glicentin in the gastric mucosa, thus supporting the hypothesis that H. pylori infection accelerates IM of the stomach.

Adult↗

[Phonocardiogram].

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Cardiovascular Diseases↗