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A Ozawa

Publications and source records attributed to A Ozawa.

At least 19 recordsLinked to original sources
PubMed1995

Antibiotic-associated hemorrhagic colitis without Clostridium difficile toxin in children.

We describe nine children with antibiotic-associated hemorrhagic colitis without Clostridium difficile toxin. The onset was usually sudden, with severe hematochezia and abdominal cramps. The illness quickly resolved and required no specific treatment except discontinuation of the implicated antibiotic. Early proctosigmoidoscopy was a useful diagnostic adjunct. It appears that antibiotic-associated hemorrhagic colitis is a distinct entity rather than a variant of antibiotic-associated colitis in children.

Adolescent↗
PubMed1995

Granulation in livers of mice infected with Salmonella typhimurium is caused by superoxide released from host phagocytes.

The pathophysiological roles of superoxide (O2.-) at the site of infection of facultative intracellular bacteria were examined in this study. To evaluate the actual in vivo generation of the superoxide, an ex vivo chemiluminescence assay was newly developed. When ICR mice were infected with a sublethal dose (8 x 10(4) CFU) of Salmonella typhimurium, the number of bacteria in the liver reached its peak at 5 days after infection (10(5.05) CFU/g of liver) and decreased thereafter. At 21 days after infection, the bacteria became undetectable. On the other hand, phorbol myristate 13-acetate-stimulated O2.- generation reached a maximum at 7 days after infection (mean photon count, 1,249 cps versus 28.8 cps before infection; n = 4) and decreased thereafter to a level similar to that before infection at 21 days after infection (28.8 cps). Histological examinations revealed that the total area of the lesions reached a peak at 7 days after infection (7.2 x 10(4) microns 2/10 visual fields). In the early phase, a microabscess with infiltration of polymorphonuclear cells was noted, and then, in the late stage, the lesion was replaced by granulation with mononuclear cell infiltration. When microscopic lesions were measured histologically, a significant correlation between the area of the lesions and phorbol myristate 13-acetate-stimulated O2.- generation was observed, which suggested that superoxide was responsible for the generation of the lesions. Modified superoxide dismutase, i.e., alpha-4-([6-(N-maleimido)hexanoyloxymethyl] cumyl)half-butyl-esterified poly(stylrene-co-malelic acid)-conjugated superoxide dismutase (SM-SOD), was then applied. When SM-SOD was administered to suppress the O2.- generation in vivo, the number of bacteria increased (10(6.1) CFU). However, the lesion formation was inhibited (total lesion area, 0.3 x 10(4) microns 2). These results suggest that the establishment of the microabscess and granuloma formation after S. typhimurium infection is not due to the bacteria per se but rather to the O2.- from the host's phagocytes. Two aspects of the O2.-, i.e., the bactericidal role and the tissue-injurious effect, were clearly demonstrated in this study. Therefore, the information obtained from these results is useful in designing treatment strategy for similar kinds of infection.

Animals↗
PubMed1995

[Post operative mediastinitis: the experience of two cases after graft replacement of the ascending aorta].

A mediastinitis after a graft replacement of the ascending aorta is serious complication and sometimes could be lethal. We have experienced two cases of such a condition, recently. In both cases, the debridement of the mediastinum and omental transposition were performed. Case 1 had a recurrent mediastinitis due to residual dead space infection, but was cured by a percutaneous drainage and a continuous irrigation. In case 2, the omentum was carefully positioned to occupy the dead space around the graft, because of the experience of the first case and gave a good result. We believe that omental transposition is an effective treatment for the postoperative mediastinitis.

Adult↗
PubMed1994

Endoscopic ethanol injection for treatment of bleeding peptic ulcer.

We treated three children aged 10, 11 and 13 years with actively bleeding ulcers using local endoscopic injection of pure ethanol. Ethanol was injected into several sites around a visible vessel with or without bleeding. Haemostasis following ethanol injection therapy was confirmed by endoscopy performed the day after treatment. No rebleeding was observed. There were no complications related to the procedure. Injection therapy is technically simple and inexpensive. Conclusion Our results suggest that endoscopic ethanol injection is safe and may be the treatment of choice for control of bleeding from peptic ulcers in children.

Adolescent↗
PubMed1994

Efficacy of twice-daily cimetidine in pediatric peptic ulcer.

The clinical efficacy of twice-daily cimetidine (20 mg/kg/day) was retrospectively studied in 19 children with gastric ulcer (GU) and 23 with duodenal ulcer (DU) in the active stage. Endoscopically confirmed cumulative healing rates at 2, 4, and 8 weeks of treatment were 53.5, 73.7, and 94.7% in the GU group and 15.4, 50.0, and 87.0% in the DU group, respectively. There was no significant difference between the groups at each time point. The mean period of time until complete disappearance of symptoms in the GU and DU groups was 3.5 +/- 2.6 and 4.2 +/- 3.3 days, respectively (NS). With regard to symptoms, abdominal tenderness rather than spontaneous pain appeared to be a better indicator of ulcer healing. Ulcer recurrence was found endoscopically during follow-up in 2 of 13 GU patients (15.4%) and 11 of 19 DU patients (57.9%); thus, the cumulative recurrence rate of the DU group was higher than that of the GU group (p < 0.05). No adverse effects related to cimetidine were demonstrated during treatment or short-term follow-up. We conclude that twice-daily cimetidine at a dosage of 20 mg/kg/day is as effective for the symptomatic improvement and healing of peptic ulcer as the conventional three- or four-times-daily regimens. The optimal dosage of cimetidine requires further study.

Adolescent↗
PubMed1994

Growth inhibition of Clostridium difficile by intestinal flora of infant faeces in continuous flow culture.

Growth of Clostridium difficile was inhibited more strongly in continuous flow (CF) culture with C. difficile-negative faeces of infants than with C. difficile-positive faeces. Culture of faecal flora of infants yielded a greater variety of bacterial species in C. difficile-negative than in C. difficile-positive faeces. In the mixed CF culture of C. difficile with Enterococcus avium, Bacteroides distasonis, Eubacterium lentum, C. ramosum, C. perfringens and either Escherichia coli or Klebsiella pneumoniae isolated from C. difficile-negative faeces, inhibition of growth of C. difficile was demonstrated when the pH of the culture medium was decreased. Amino-acid analysis of CF cultures showed considerable utilisation of aspartic acid, serine, threonine, arginine and asparagine. A marked increase in concentrations of citrulline and ornithine was found in the culture that inhibited growth of C. difficile. The addition of citrulline and ornithine into a Gifu anaerobic medium (GAM) broth produced no inhibition of growth of C. difficile. The addition of the mixture of the depleted amino acids (aspartic acid, serine, threonine, arginine and asparagine) to the culture filtrate or adjustment of the pH of the culture filtrate induced considerable growth of C. difficile. These results suggest that the inhibition of growth of C. difficile may be due to consumption of amino acids by intestinal flora, and not to the presence of inhibitors produced by the intestinal flora.

Amino Acids↗
PubMed1994

Anaphylactoid purpura with intestinal perforation: report of a case and review of the Japanese literature.

A 78 year old man suffering from anaphylactoid purpura complained of abdominal pain and bloody stools. Combined therapy with Prednisolone and cyclophosphamide had been given against nephrotic syndrome caused by purpura nephritis. Severe abdominal pain with symptoms and signs of pan-peritonitis necessitated laparotomy. Rectosigmoid perforation due to necrotizing angiitis (phlebitis) was also demonstrated histologically. The patient died of septicemia 18 days after surgery. Perforation of the alimentary tract rarely occurs in anaphylactoid purpura. Twenty similar cases were briefly reviewed from the Japanese literature.

Aged↗
PubMed1994

Plasma insulin-like growth factor-I response to cold exposure in barrows.

Information about the plasma IGF-I concentrations in domestic animals in a cold environment is still limited. And mechanisms to change plasma IGF-I concentrations in cold environments are not fully elucidated. In this study, plasma insulin-like growth factor-I (IGF-I) in relation to plasma growth hormone (GH) and metabolite concentrations was investigated in pigs living at 20 degrees C and at 4 degrees C. Six pigs (Landrase breed; barrows, 118 days old, 51.0 +/- 3.5 kg body weight) were maintained for 2 weeks at 20 degrees C in a climatic room. Then a placebo or recombinant bovine GH (100 micrograms/kg body weight) was injected subcutaneously. Blood samples were taken through a catheter at -2, 0, 1, 2, 3, 4, 5, 6, 9, 12, 22, and 24 h after the injections. The same experiments were conducted on days 5 and 6 after the room temperature was changed to 4 degrees C. Mean (+/- SD) basal plasma GH concentrations in pigs without bovine GH administration living at 20 degrees C and at 4 degrees C were 4.8 +/- 1.7 ng/ml and 4.6 +/- 2.8 ng/ml, respectively. There were no significant differences between GH concentrations. On the other hand, the mean plasma IGF-I concentrations were 80.8 +/- 25.1 ng/ml and 57.3 +/- 14.3 ng/ml respectively. Plasma IGF-I concentrations in pigs living at 4 degrees C were significantly lower than in pigs living at 20 degrees C (P < 0.05). Plasma glucose and non-esterified fatty acid (NEFA) concentrations in pigs at 4 degrees C were significantly higher than in pigs at 20 degrees C (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Characteristics of vacuolating toxin produced by Helicobacter pylori.

OBJECTIVE: We sought a good indicator cell line to use in detecting the vacuolating toxin produced by Helicobacter pylori and in examining the characteristics of the toxin. DESIGN AND METHODS: Using five cell lines [baby hamster kidney (BHK-21), human amnion (FL), human uterine cancer (HeLa), rabbit kidney (RK-13) and African green monkey kidney (Vero)], cytotoxicity assays were performed with 33 H. pylori strains. To analyse the proteins produced by toxigenic and non-toxigenic strains, immunoblotting was done with the sera of patients with gastroduodenal diseases. RESULTS: When RK-13, FL, Vero, BHK-21 and HeLa cells were used for the assay, 73, 61, 27, 27 and 21% of strains, respectively, were toxigenic. The vacuolating toxin is sensitive to heat at 70 degrees C. By immunoblot analysis, under non-denaturing conditions, immune sera recognized proteins with molecular weights of 600,000 and 500,000 in the toxigenic but not in the non-toxigenic strains. CONCLUSION: H. pylori produces vacuolating toxin, which is a heat-sensitive protein at 70 degrees C and is easily detectable by cytotoxicity assay using the RK-13 cell line. Toxigenic H. pylori strains produce various proteins, including this toxin, which are recognized by sera from patients with gastroduodenal diseases.

Animals↗
PubMed1994

[An autopsy case of lung cancer metastasizing to renal cell cancer and rectal villous adenoma].

A 67-year-old woman with bloody stool was admitted to our hospital. Chest radiograph on admission showed a tumor shadow in the right lower lung field. Lung adenocarcinoma of right S6 and villous adenoma of the rectum were detected. Although she was treated with chemotherapy and radiotherapy, she died of respiratory failure. At autopsy, moderately differentiated adenocarcinoma of the right lung, renal cell carcinoma, and villous adenoma of the rectum were confirmed. Lung adenocarcinomas were detected in the focus of the renal cell carcinoma and in the villous adenoma. Metastasis of a cancer into another coexisting tumor in the same individual is extremely rare, and a satisfactory explanation for this phenomenon has not yet been offered.

Adenocarcinoma↗
PubMed1993

Evaluation of rapid urease test for detection of Helicobacter pylori in gastric biopsy specimens.

Using 80 gastric biopsy specimens from patients with various gastroduodenal diseases, the isolation rate of H. pylori and urease activity of the biopsy specimens were examined. The sensitivity and specificity of the rapid urease test was 84.6% and 75.9%, respectively, for the cultivation of H. pylori. The mean number of H. pylori detected in urease-positive and negative biopsy specimens was 10(6.1 +/- 0.9) and 10(4.5 +/- 1.2) cfu/g specimens, respectively.

Adult↗
PubMed1993

Ecological study on the intestinal bacteria flora of patients with diarrhea.

In the intestinal flora of patients with diarrhea, a close correlation exists between a decrease in numbers of anaerobes and a reduction in levels of short-chain fatty acids. The drastic reduction of intestinal volatile fatty acids (VFAs) accompanying decreased counts of anaerobes during the diarrheal state and the increase in pH thought to arise from these changes result in increased fecal water content. Our data suggest that free bile acids and VFAs may be factors controlling intestinal bacterial populations in vivo, especially in enteric infections. Thus the role of nonspecific factors such as VFAs, which are among the bile acid metabolites produced by anaerobic intestinal bacteria, deserves emphasis in the evaluation of protective mechanisms provided by the intestinal flora against enteric infections.

Adolescent↗
PubMed1992

Effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) on hemopoiesis and survival rate following allogeneic bone marrow transplantation in mice.

The effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) on the survival rate and hemopoiesis after allogeneic bone marrow transplantation (BMT) were examined. Specific pathogen-free (SPF) C3H mice and germ-free C3H mice, kept in an isolator for germ-free animals, received 10 Gy of total body irradiation (TBI) and all the mice died by day 9 after TBI. These survival rates were improved by BMT. In the case of SPF mice, survival rates at 14 and 100 days were 33% (12/36), 17% (6/36) and in the case of germ-free mice they were 79% (15/19), 74% (14/19) respectively. When SPF mice received rhG-CSF (30 micrograms/kg/day) subcutaneously for 14 consecutive days following BMT, their survival rates were improved to 79% (30/38), 79% (30/38) respectively. The survival rate of rhG-CSF treated SPF mice were equal to that of germ-free mice. When the effect of rhG-CSF treatment on hemopoiesis of SPF mice after allogeneic BMT was examined various hematopoietic progenitor cells in the bone marrow and spleen increased until day 10 after, BMT, while only neutrophils increased in the peripheral blood during the period. No adverse effects of rhG-CSF were observed throughout the study period. It was suggested that in SPF mice treated with rhG-CSF after BMT, the neutrophil recovered in counts quickly and increased neutrophil prevented endogenous infections and improved the survival rate without apparent complications.

Animals↗
PubMed1991

Variations in serum levels of insulin-like growth factor-1, growth hormone and thyroid hormones during lactation in dairy cows.

1. Serum levels of insulin-like growth factor-1 (IGF-1) in dairy cows declined after parturition, remained low during the period of early lactation with peak milk production and rose gradually until the end of lactation thereafter. 2. Growth hormone (GH) levels in sera of cows changed in parallel with milk yields. 3. Serum thyroxine and triiodothyronine levels during lactation remained fairly constant.

Animals↗
PubMed1991

[Clinical significance of gastrointestinal decontamination under protected environment].

Many infections are caused by the patient's own oro-intestinal microbial flora under a protected environment. Thirty-eight patients with acute leukemia and two patients with blast crisis of chronic myelocytic leukemia were treated under a protected environment with or without prophylactic antibiotics. Antibiotics used for decontamination were vancomycin (V), polymyxin B (P) and nystatin (N). The number of patients in the VPN, PN and the no antibiotic group were 13, 13 and 14, respectively. While the intestinal microbial flora was almost completely eliminated in VPN group, the number of bacteria decreased slightly in PN group. The mean number of pharyngeal and anorectal bacterial species decreased most markedly in the VPN group, but there were no significant differences among the three groups. The number of febrile days was significantly lower in the VPN and PN group than the no antibiotics group with neutrophil counts of less than 100 microliters. The average number of episodes of infection per patient was lowest in VPN group and highest in the no antibiotic group. These data indicate that VPN administration is effective for eliminating intestinal bacterial flora and resultantly protecting endogenous infections.

Adolescent↗