Search PubMed⌕ Search

Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 235 records · Page 13Linked to original sources
PubMed1995

Peptic ulcer recurrence after Helicobacter pylori eradication: a 5-year follow-up study.

OBJECTIVE: To investigate whether eradication of Helicobacter pylori prevents peptic ulcer recurrence in the long term. PATIENTS AND METHODS: We treated 81 patients with endoscopically proven H. pylori-related peptic ulcers (39 with gastric ulcers and 42 with duodenal ulcers) with either amoxycillin or clarithromycin in combination with a proton-pump inhibitor or a histamine H2-receptor antagonist. The patients were followed for a recurrence of peptic ulcers for at least 5 years. Recurrence was assessed by endoscopy and the status of H. pylori was evaluated by culture, a rapid urease test and a histological examination. RESULTS: After 5 years of follow-up, the rate of recurrence of H. pylori-related duodenal ulcers decreased significantly (P < 0.0001) in the H. pylori-eradicated patients compared with non-eradicated patients. However, in the gastric ulcer group, there was no significant reduction in the recurrence rate. CONCLUSIONS: Our findings suggest that eradication of H. pylori significantly reduces the rate of duodenal ulcer relapse and that this relapse is associated with the presence of H. pylori. Therefore, H. pylori eradication may be considered a definitive cure for duodenal ulcers.

Adolescent↗
PubMed1995

Influence of Helicobacter pylori infection and the effects of its eradication on gastric emptying in non-ulcerative dyspepsia.

AIM: The aim of the present study was to clarify the effects of Helicobacter pylori infection and its eradication on gastric emptying. SUBJECTS AND METHODS: Out of a total of 52 patients with non-ulcerative dyspepsia, 34 H.pylori-positive patients were enrolled. Antimicrobial drugs for the eradication of H. pylori were administered to 19 out of the 34 H. pylori-positive patients. Gastric emptying was evaluated according to the acetaminophen method. Inflammatory changes and intracellular periodic acid-Schiff-positive substances in the antral mucosa were examined in biopsy specimens. RESULTS: Although gastric emptying was significantly prolonged in the patients with non-ulcerative dyspepsia compared with the control group (P < 0.01), there was no difference in gastric emptying between H. pylori-positive and -negative patients, with all patients showing significantly less gastric emptying than the control group. The H. pylori eradication rate was 58% (11 out of 19) and gastric emptying improved significantly in seven patients whose infection was eradicated and whose dyspeptic symptoms disappeared. The ammonia concentration in gastric juice, inflammatory changes in the gastric mucosa and the index of periodic acid-Schiff-positive substances improved significantly when H. pylori was successfully eradicated compared with patients in whom eradication was unsuccessful. As gut hormones may affect gastroduodenal motility associated with H. pylori infection, we also studied the levels of serum gastrin and cholecystokinin. In the patients whose infection was eradicated, serum gastrin decreased significantly, but the cholecystokinin level did not change significantly, although there was a non-significant trend for cholecystokinin to increase. CONCLUSIONS: These results suggest that delayed gastric emptying is partly associated with H. pylori infection and that the infection may contribute to the development of non-ulcerative dyspepsia.

Adult↗
PubMed1994

Disseminated Trichosporon beigelii infection in patients with malignant diseases: immunohistochemical study and review.

Trichosporon beigelii is a causative agent of opportunistic infection and summer-type hypersensitivity pneumonitis in Japan. However, as the diagnosis of Trichosporon beigelii infection is sometimes difficult, the actual incidence of this disease may be underestimated. Of 203 autopsy patients with malignant disease, seven (7.7%) were diagnosed with disseminated Trichosporon beigelii infection by immunohistochemical investigation of formalin-fixed, paraffin-embedded tissue sections. Including these seven, a total of 43 patients with Trichosporon beigelii infection have been reported in Japan. The majority of them had underlying hematologic malignancies, for which they received cytotoxic chemotherapy resulting in neutropenia. This study indicates that the immunohistochemical method, which can be applied to biopsy specimens, is an excellent tool for specific diagnosis of Trichosporon beigelii infection, which is an emerging fatal mycosis in immunocompromised patients with profound neutropenia.

Aged↗
PubMed1994

In-vitro effects of antimicrobial agents on Pseudomonas aeruginosa biofilm formation.

The in-vitro effects of ten antimicrobial agents on the biofilm formation of Pseudomonas aeruginosa were investigated. The production of alginic acid by mucoid P. aeruginosa cells cultured in agar media with sub-MICs of antimicrobial agents was quantified by high-performance liquid chromatography. Alginic acid production was inhibited by 1/4 MIC of minocycline (P < 0.002) and tobramycin (P < 0.02), and by 1/256-1/1/64 MIC of macrolides (erythromycin, clarithromycin, roxithromycin, and rokitamycin) and clindamycin (P < 0.02), compared with drug-free controls. Piperacillin, ceftazidime, and ofloxacin did not inhibit alginic acid production. The production of exopolysaccharide by non-mucoid P. aeruginosa cells grown on silicone plates in sub-MICs of antimicrobial agents was determined by quantitative tryptophan assay. Exopolysaccharide production was inhibited by 1/16 MIC of macrolides and clindamycin, but not by other antimicrobial agents. Electron microscopy showed that biofilm formation by mucoid and non-mucoid type P. aeruginosa strains was inhibited by sub-MICs of erythromycin and correlated with the in-vitro production of alginic acid and exopolysaccharide. These results suggest that sub-MICs of macrolides and clindamycin suppress biofilm formation by P. aeruginosa and that intractable chronic respiratory tract infections due to P. aeruginosa might be prevented.

Alginates↗
PubMed1994

Exogenous free iodotyrosine inhibits iodide transport through the sequential intracellular events.

We describe a new function of exogenous iodotyrosine as a regulator of iodide transport. Porcine thyroid follicles in culture were preincubated with 0-20 mumol/l monoiodotyrosine or diiodotyrosine (DIT) in the presence of bovine thyrotropin (TSH) for 24 h; these iodotyrosines inhibited iodide uptake in a dose-response manner. Extracellular [125I]DIT was actively transported to the thyroid follicle in the presence of TSH or (Bu)2cAMP. Inhibition of iodide uptake by iodotyrosine required preincubation with iodotyrosine in the presence of TSH; without TSH, iodotyrosine was ineffective. Follicles preincubated with DIT for 24 h inhibited TSH-mediated cAMP production, which is an important signal for iodide transport. Inhibition of iodide uptake and cAMP generation by iodotyrosine was negated characteristically by 3-nitro-L-tyrosine, an inhibitor of iodotyrosine deiodinase, or by methimazole, an inhibitor of thyroid peroxidase. Our findings suggest that iodotyrosine regulates iodide transport through the following sequential intracellular events: TSH-dependent iodotyrosine transport into the thyroid cell; deiodination of iodotyrosine and release in iodide; iodine organification by the peroxidase system; inhibition of cAMP generation by organified iodine; and inhibition of iodide transport. Thus, exogenous iodotyrosine can serve as an inhibitor of thyroid hormone formation only when TSH is present.

Animals↗
PubMed1994

Clinicopathological features of adult T-cell leukemia with CD30 antigen expression.

Recently, several cases of adult T-cell leukemia (ATL) with CD30 antigen have been reported, but its clinical significance remains unknown. Accordingly, we studied CD30 antigen expression in ATL cases and documented the clinicopathological characteristics of these cases. Immunohistochemical and clinical characteristics were studied in 46 patients with malignant lymphoma or benign lesions of lymphoid tissue, who had antibodies against human T-cell leukemia virus type I (HTLV-I). Monoclonal integration of HTLV-I provirus was demonstrated in the tumor cells in 36 (ATL) of the 46 cases. CD30 antigen expression was evident in seven of these 36 cases (19.4%), however it was not seen in any of the ten cases lacking the integration of HTLV-I provirus. A comparison of ATL cases with and without CD30 antigen expression revealed significantly larger numbers of abnormal lymphocytes in the peripheral blood and lower serum calcium levels in ATL expressing CD30 antigen.

Adult↗
PubMed1994

Combination therapy with clarithromycin and sofalcone for eradication of Helicobacter pylori.

OBJECTIVE: To clarify the efficacy of combination therapy with clarithromycin and sofalcone for eradication of Helicobacter pylori. DESIGNS: We studied 42 patients with H. pylori-positive gastroduodenal diseases, who were divided into two groups according to treatment period. Group 1 comprised 27 patients (seven with gastric ulcers, 14 with duodenal ulcers and six with gastritis) treated with a combination of clarithromycin (200 mg, three times a day) + sofalcone (100 mg, three times a day) for 3 weeks. Group 2 comprised 15 patients with chronic active gastritis treated with the same doses of clarithromycin + sofalcone but for only 2 weeks (group 2). The H. pylori status of all patients was assessed by culture, rapid urease test and histological examination at the end of treatment and 4 weeks after the end of treatment. The gastritis score, the index of intracellular periodic acid-Schiff-positive substance in the antral mucosa and the ammonia concentration in gastric secretions were also estimated before and after treatment. RESULTS: In group 1, with over half the patients excluded from the follow-up, H. pylori was eradicated in nine out of 13 patients (69.2%) compared with six out of the complete group of 15 (40.0%) patients in group 2, without serious side effects. In these patients, significant improvements were seen in the gastritis score (P < 0.025), the index of periodic acid-Schiff-positive substances in the antral mucosa (P < 0.025) and the ammonia concentration in gastric secretions (P < 0.02) after treatment. CONCLUSION: These results suggest that modification of the treatment regimen is needed, with higher doses of clarithromycin and combination therapy with proton-pump inhibition.

Ammonia↗
PubMed1994

Establishment of an animal model for chronic gastritis with Helicobacter pylori: potential model for long-term observations.

OBJECTIVES: To assess the suitability of an established experimental model for chronic gastritis associated with Helicobacter pylori for use in long-term observations. DESIGN: In a 3-year follow-up study of acute gastritis induced by H. pylori using an established experimental model with Japanese monkeys, we compared H. pylori-infected animals (n = 6) with a non-infected control group (n = 7). Colonization by H. pylori, gastritis scores, volume of intracellular periodic acid-Schiff-positive substances and the height of antral glands were investigated every 3 months for 3 years and compared with those of a control group. RESULTS: In the infected group, persistent colonization with H. pylori was demonstrated by culture and histological examinations. Gastritis scores were significantly higher than those of the control group, and the histological findings were quite similar to those of chronic active gastritis observed in humans. Simultaneously, significant decreases in the contents of periodic acid-Schiff-positive substances and in the height of antral glands were also demonstrated in infected animals. CONCLUSION: In Japanese monkeys, persistent colonization with H. pylori caused chronic gastritis quite similar to that observed in humans, thus providing a suitable animal model for evaluating the long-term prognosis of H. pylori infection.

Animals↗
PubMed1994

[Clinical studies on the time-difference combination therapy with netilmicin and minocycline in methicillin-resistant Staphylococcus aureus infections].

Twenty-eight patients with methicillin-resistant Staphylococcus aureus (MRSA) infections were clinically studied for the effectiveness of the time-difference combination use of netilmicin (NTL) and minocycline (MINO). The patients were treated with NTL 100 mg and two hours later, with MINO 100 mg intravenously, twice daily, in the morning and evening for 14 days. Of 26 patients, MRSA was eradicated in 16 (61.5%), decreased in one, and unchanged in nine. Superinfections occurred with Serratia marcescens and Pseudomonas aeruginosa in two patients. The clinical efficacies were assessed in two patients with septicemia, 16 with pneumonia, and eight with chronic bronchitis. The obtained results were excellent in four patients, good in 15, fair in six, and poor in one patient. The rate of effectiveness was 73.1% (19/26). The overall clinical effectiveness judged by the committee was good in 19, fair in five, and poor in two patients. The efficacy rate was also 73.1% (19/26). Coagulase type II of MRSA was found in 23 patients, and coagulase type III in three patients, with overall clinical efficacy rates of 73.9% (17/23) and 66.7% (2/3), respectively. A side effect of eruption was observed in one patient, and its incidence was 3.6% (1/28). Abnormal laboratory test results were observed in 16 patients (57.1%), including abnormal liver function in 14 patients, abnormal kidney function in three, and increased eosinophils in three. Laboratory abnormalities occurred twelve of 16 bedridden patients, and this rate was higher than that in non bedridden patients. However, these abnormalities were all mild, transient, and immediately recovered after the treatment. In conclusion, the time-difference combination therapy using NTL and MINO was effective in the treatment of MRSA infections.

Adolescent↗
PubMed1994

[Problems concerned with adult T-cell leukemia. 1) Causes of death and early diagnosis of cytomegalovirus pneumonia in adult T-cell leukemia. 2) Clinicopathological features of CD30 positive adult T-cell leukemia].

1) We studied the causes of death confirmed by autopsy or necropsy in 23 adult T-cell leukemia (ATL) patients. Of them eight showed involvement of tumor (35%), eleven infectious disease (47%) (nine cytomegalovirus (CMV) pneumonia, one varicella-zostervirus pneumonia, one pseudomonas aeruginosa pneumonia), and four others (17%). In seven recent cases treated with a new chemotherapy regimen in combination with G-CSF administration, survival was longer than in previous cases and tumor involvement as a cause of death decreased (one case, 14%). However, CMV pneumonia inclined to increase (six cases, 86%). Therefore, we tried to retrospectively detect CMV DNA in the serum of ATL patients using a nested polymerase chain reaction (PCR). CMV pneumonia was reliably diagnosed in eleven ATL patients, whereas CMV DNA was detected in all patients at the time of clinical onset of pneumonia and CMV DNA was detected only in eight patients from 7-35 days before the onset of pneumonia. These findings suggest that the nested PCR assay is a useful tool to early diagnosis CMV pneumonia in ATL patients. 2) Recently, several cases of ATL with CD30 antigen have been reported, but its clinical relevance remains unknown. Accordingly, we studied CD30 antigen expression in 36 ATL patients who had monoclonal integration of HTLV-I provirus in the tumor cells and demonstrated the immunohistochemical and clinical characteristics of these patients. CD30 antigen expression was evident in seven of these 36 patients (19.4%). A comparison of ATL cases with and without CD30 antigen expression revealed significantly large numbers of abnormal lymphocytes in the peripheral blood and lower serum calcium levels in CD30 antigen positive ATL.

Adult↗
PubMed1994

A case of nephrotic syndrome associated with traumatic chronic osteomyelitis.

A 19-year-old male developed nephrotic syndrome during the course of chronic osteomyelitis complicating a traumatic suppurative arthritis of the knee. Renal biopsy revealed severe mesangial proliferative glomerulonephritis, and immunofluorescent microscopy demonstrated the presence of IgA. Nephrotic syndrome remitted during the treatment for chronic osteomyelitis, suggesting a close association of the two conditions.

Adult↗
PubMed1994

[A case of malignant hemangiopericytoma arising from the mediastinum accompanied by hepatocellular carcinoma].

A 65-year-old man was admitted to Oita Medical University Hospital with complaints of right back pain, diplopia and vertigo. A tumor, 33 x 25 mm, was found on the right lateral chest wall on admission. Chest X-ray film and chest CT scan showed a tumor, 50 x 30 mm, in the right posterior mediastinum. The chest wall tumor was diagnosed as malignant hemangiopericytoma by biopsy, and the same diagnosis was made for the mediastinal lesion by aspiration cytology. Brain MRI showed a mass at the skull base, which was found to be a metastatic bone tumor from the mediastinal malignant hemangiopericytoma. Abdominal CT scan showed a massive tumor, 65 x 60 mm, in the right lobe of the liver. The liver tumor was diagnosed as hepatocellular carcinoma by biopsy. Combination chemotherapy, employing cyclophosphamide, vincristine, pirarubicin and dacarbazine (DYVADIC), in conjunction with radiation therapy, produced no response. The patient died 5 months after admission. Malignant hemangiopericytoma arising from the mediastinum is uncommon. Thus, the clinical features of our case, as well as those of previously reported cases in Japan, are discussed herein.

Aged↗