PubMed Health⌕ Search

Biomedical subjects

Masaharu Nishimura

Publications and source records attributed to Masaharu Nishimura.

103 records · Page 6Linked to original sources
PubMed2002

Role of contrast-enhanced dynamic CT in the diagnosis of active tuberculoma.

STUDY OBJECTIVES: To assess the role of contrast-enhanced dynamic CT in the diagnosis of active tuberculoma. SETTING: Hospitals with an isolated ward for tuberculosis. METHODS: Fifty-five subjects with newly diagnosed active tuberculoma and 24 subjects with inactive tuberculoma were examined and evaluated retrospectively. Six subjects with active tuberculomas and seven subjects with inactive tuberculomas were confirmed by histologic and microbiologic evaluation of resected specimens, whereas the remainder of the subjects with tuberculoma were confirmed clinically. The subjects were receiving iopamidol, 370 mg/mL IV, at a rate of 3.0 mL/s on contrast-enhanced dynamic CT. The time-attenuation curve was obtained and adapted to a gamma function. The peak height (PH), maximum attenuation subtracted by the background attenuation, relative flow (RF), and mean regional flow were used for comparison. MEASUREMENTS AND RESULTS: In the surgically confirmed group, the PH and RF values of six subjects with active tuberculomas were significantly higher than those of the seven subjects with inactive tuberculoma (p < 0.05). Similarly, in the subjects with noninvasive diagnoses, the PH and RF values of 49 subjects with active tuberculoma were significantly higher than those of the subjects with inactive tuberculoma (mean +/- SD PH, 43.4 +/- 4.1 Hounsfield units [HU] vs 11.6 +/- 2.7 HU, p < 0.0001; RF, 0.012 +/- 0.001/s vs 0.006 +/- 0.001/s, p < 0.05). When the cutoff value was defined as mean +/- 2 SD, the sensitivity and specificity of the diagnosis for active tuberculoma were 77.1% and 96.4% in PH, and 68.5% and 88.8% in RF, respectively. CONCLUSION: Contrast-enhanced dynamic CT is a potentially valuable tool for the diagnosis of active tuberculoma.

Adult↗
PubMed2002

Tissue hypoxia in sleep apnea syndrome assessed by uric acid and adenosine.

STUDY OBJECTIVE: Although the overnight increase in urinary uric acid/creatinine ratio (DeltaUA/Cr) is considered by some to be a marker of tissue hypoxia in patients with obstructive sleep apnea-hypopnea syndrome (OSAS), this index is not universally accepted. The purpose of this study was to confirm the validity of DeltaUA/Cr as a marker of tissue hypoxia by measuring the plasma level of adenosine during sleep, and also to test the hypothesis that the heart rate (HR) response to apnea is a determinant of tissue hypoxia. DESIGN: Intergroup comparative study. SETTING: A university hospital, Sapporo, Japan. PATIENTS: Eighteen patients with OSAS who had apnea-associated, moderate-to-severe arterial desaturation. The patients were classified into two groups: the DeltaUA/Cr-positive group, who were considered to have tissue hypoxia, and the DeltaUA/Cr-normal group, who were not. MEASUREMENTS AND RESULTS: Although there were no significant differences between two groups of the patients in either arterial desaturation parameters or the apnea-hypopnea index, the plasma level of adenosine during sleep was significantly higher in the DeltaUA/Cr-positive group than in the DeltaUA/Cr-normal group. Successful treatment with nasal continuous positive airway pressure significantly decreased both DeltaUA/Cr and the plasma level of adenosine only in the DeltaUA/Cr-positive group. The magnitude of the HR increase after the termination of apnea was significantly smaller in the DeltaUA/Cr-positive group. CONCLUSIONS: DeltaUA/Cr is a marker of tissue hypoxia, which does not necessarily parallel arterial desaturation indexes in OSAS. Intersubject variability in the HR response to apnea may explain the discrepancy between tissue hypoxia and arterial desaturation indexes.

Adenosine↗
PubMed2002

A case of diabetes, deafness, cardiomyopathy, and central sleep apnea: novel mitochondrial DNA polymorphisms.

We describe a case of diabetes mellitus complicated by neurosensory hearing loss, cardiomyopathy, and sleep apnea syndrome. A 48-year-old man who was admitted for treatment of a lacerated tendon of the right shoulder was also found to require preoperative control of diabetes, a condition that had been diagnosed 4 years earlier. The family pedigree suggested maternal inheritance of diabetes. The patient also had neurosensory hearing loss and the central type of sleep apnea syndrome. His myocardium was hypertrophic and the ultrastructural analysis showed morphologically abnormal mitochondria. On the basis of the apparent characteristic manifestations, we speculated that he had a mitochondrial disease. To elucidate the responsible mutation of mitochondrial DNA, we sequenced the patient's entire mitochondrial DNA derived from blood leukocytes and found 40 sequence variants. Three of those, 5466 A/G, 7912 G/A, and 10601 T/C, have not yet been reported. Nine of the 40 variants were accompanied by an amino acid replacement, including 5466 A/G. Although we could not determine the most significant mutation, the variants of mitochondrial DNA may have been associated with this patient's unusually variable clinical manifestations.

Cardiomyopathies↗
PubMed2002

Pulmonary actinomycosis followed by pericarditis and intractable pleuritis.

A case of pleuropericarditis caused by Actinomyces israelli is described. The patient first underwent left upper lobectomy because of pulmonary actinomycosis. Seven months later, cardiac tamponade developed. Culture of the bloody pericardial effusion resulted in positive growth of Actinomyces israeli. He was successfully treated with penicillin G, ampicillin, and minocyclin. However, right pleural effusion appeared two months later. Cultures of the effusion again yielded positive growth of the same bacteria. However, the strain had gained resistance to any antibiotics that had been effective before. Accordingly, pleurodesis with minocyclin was undertaken, which was fortunately effective for controlling the pleural effusion.

Actinomyces↗
PubMed2002

Inflammatory pseudotumor of the mesentery causing portal venous thrombosis and cavernomatous transformation.

A 32-year-old man was admitted to our hospital complaining of abdominal pain in the left upper quadrant. A mass was palpable on the left side of the umbilicus. Laboratory data revealed anemia, elevated erythrocyte sedimentation rate, hypergammaglobulinemia, and prolonged prothrombin time. Computed tomography demonstrated a soft tissue mass in the mesentery of the jejunum, portal venous thrombosis, and cavernomatous transformation in the porta hepatis. The patient was eventually diagnosed by laparoscopic partial resection as having inflammatory pseudotumor of the mesentery. Four months later, all of his symptoms and abnormal laboratory findings completely disappeared without any therapy. Inflammatory pseudotumor should be kept in mind as a cause of portal venous thrombosis, and/or cavernomatous transformation although it is rare.

Adult↗
PubMed2002

[A case of sarcoidosis complicated by primary Sjögren's syndrome].

A 35-year-old woman had been suffering for 10 years from a dry mouth and dry eyes without being medically examined. When she finally saw a doctor in September 1996, a chest radiograph revealed bilateral hilar lymphadenopathy. Histopathological examination of the lung and scalene lymph nodes revealed non-specific lymphadenitis. She was followed thereafter without any therapy. In 1997, she was referred to our hospital because of a high titer of antinuclear antibody. A diagnosis of Sjögren's syndrome was made on the basis of the results of sialography, lip biopsy, Schirmer's test, and the present of anti-SS-A antibody. Re-evaluation of the mediastinal lymph nodes and the lung by thoracoscopic biopsy revealed non-caseating epithelioid cell granulomas, which led to a diagnosis of sarcoidosis. Although the coexistence of Sjögren's syndrome and sarcoidosis has been reported occasionally, cases with histological proof of sarcoidosis have been rare. In a survey of 27 reported cases, the majority of the patients were female and in roentgenological stage I. In most cases, Sjögren's syndrome preceded sarcoidosis. The predominance of the Th 1 immune response at the site of each disease may be involved in the pathogenic mechanism by which these diseases coincide.

Adult↗
PubMedDate not supplied

Mediastinal lymph node staging by FDG-PET in patients with non-small cell lung cancer: analysis of false-positive FDG-PET findings.

BACKGROUND: Accurate staging of mediastinal and hilar lymph nodes is a critical factor determining operability in patients with non-small cell lung cancer (NSCLC). Positron emission tomography with 2-[18F] fluoro-2-deoxy-D-glucose as a tracer (FDG-PET) has recently been reported to be more effective in detecting tumor involvement in mediastinal and hilar lymph nodes than computed tomography (CT). OBJECTIVE: In this study, we analyzed the accuracy of FDG-PET in mediastinal and hilar lymph node staging in patients with NSCLC and the factors associated with false-positive or false-negative FDG-PET findings in mediastinal and hilar lymph node staging. METHODS: Fifty-four patients with NSCLC who underwent preoperative analysis including chest CT and whole-body FDG-PET were evaluated retrospectively. Using FDG-PET, lesions were considered to be positive if a definite, localized area of higher uptake, excluding physiologic uptake, than in surrounding normal tissue was present. On CT findings, lymph nodes were considered to be positive if they were >10 mm in short-axis diameter, except subcarinal lymph nodes (#7), which were considered to be positive if they were >15 mm in short-axis diameter. All patients underwent surgical resection of primary tumors and mediastinal and hilar lymph nodes between 1999 and 2001 in our institute. Resected lymph nodes were histologically examined for the existence of tumor cells. RESULTS: A total of 306 lymph nodes were resected and used for analysis. The sensitivity, specificity, positive predictive value and negative predictive value of FDG-PET were 73, 98, 70 and 98%, while those of CT were 55, 96, 55 and 96%, respectively. When pre-operative nodal staging was compared with post-operative histopathological staging, 44 patients (81%) were correctly staged, 7 (13%) were overstaged and 3 (6%) were understaged by FDG-PET, while 39 patients (72%) were correctly staged, 8 (15%) were overstaged and 7 (13%) were understaged by CT. All 7 overstaged patients by FDG-PET had other pulmonary complications, including interstitial pneumonitis (n = 2), previous pulmonary tuberculosis (n = 3), silicosis (n = 1) and emphysema (n = 1), although they were not in the active stage. In 3 understaged patients by FDG-PET, lymph nodes were also undetectable by CT. CONCLUSION: FDG-PET is superior to CT in mediastinal and hilar lymph node staging of patients with NSCLC. However, care should be taken in lymph node staging for patients who have other pulmonary complications, including interstitial pneumonitis, previous pulmonary tuberculosis and silicosis.

Adenocarcinoma↗
PubMedDate not supplied

Inverted papilloma of the nasal cavity presenting with massive amounts of squamous metaplastic cells in sputum. A case report.

BACKGROUND: Squamous metaplasic cells are rarely seen in sputum of female nonsmokers. CASE: A 47-year-old female nonsmoker presented with massive amounts of squamous metaplasic cells in sputum and an elevated level of squamous cell carcinoma (SCC) antigen in serum present for months, while no causative lesion was detected either by lung computed tomography or bronchoscopy. The patient was eventually diagnosed as having inverted papilloma in the right nasal cavity. Resection of the tumor brought about disappearance of squamous metaplastic cells in sputum and return of serum SCC antigen to the normal range. CONCLUSION: This case clearly demonstrates that squamous metaplastic cells in sputum can originate in lesions in the nasal cavity, although they are rare. It should be kept in mind that the nasal cavity is a potential site producing squamous metaplastic cells in sputum.

Antigens, Neoplasm↗
PubMedDate not supplied

Topoisomerase inhibitor-induced apoptosis accompanied by down-regulation of Bcl-2 in human lung cancer cells.

BACKGROUND: Anticancer drug-induced apoptosis is one of the important mechanisms in the effectiveness of chemotherapy. In this study, we investigated apoptosis induced by topoisomerase inhibitors and its relationship with chemosensitivity, the expression of Bcl-2 family proteins and p53 status in human lung cancer cells. MATERIALS AND METHODS: A total of six human lung cancer cell lines, i.e., two small cell lung cancer (SCLC) and four non-small cell lung cancer (NSCLC) cell lines, were used. For induction of apoptosis, these cell lines were treated with SN-38 (DNA topoisomerase I inhibitor) or etoposide (DNA topoisomerase II inhibitor). Drug sensitivity was determined using a microculture tetrazolium assay. The rates of apoptosis and alterations of Bcl-2 and Bax expression were analyzed by flow cytometry. RESULTS: Apoptotic cells increased in a time-dependent manner after exposure to topoisomerase inhibitors. Induction of apoptosis was accompanied by the down-regulation of Bcl-2 expression, but there was little alteration of Bax expression. These events were significantly more extensive in SCLC cell lines, which are more sensitive to topoisomerase inhibitors, than in NSCLC cell lines, which are more resistant to these inhibitors. However, neither induction of apoptosis nor chemosensitivity correlated with p53 status in the lung cancer cell lines studied. CONCLUSION: The more extensive induction of apoptosis with Bcl-2 down-regulation in SCLC than in NSCLC might explain, at least in part, the higher clinical sensitivity to topoisomerase inhibitors in the former disease.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Analysis of the response and toxicity to gefitinib of non-small cell lung cancer.

BACKGROUND: Gefitinib is an oral agent that inhibits the tyrosine kinase of epidermal growth factor receptor (EGFR), which had antitumor activity in patients with previously treated non-small cell lung cancer (NSCLC). We analyzed the efficacy, toxicity and overall survival time of gefitinib treatment in patients with NSCLC. PATIENTS AND METHODS: One hundred and twenty-two patients with NSCLC, who received gefitinib between 2002 and 2004 in our institutes, were evaluated retrospectively. RESULTS: The objective response rate was 24.6%. The variables identified as significant in univariate analysis included gender and smoking habit. The median overall survival time was 14.4 months. Significant variables associated with improved survival included good performance status (PS), female, adenocarcinoma and never smoked status, while never smoked status and good PS were independent prognostic factors in multivariate analysis. Four patients (3.3%) developed interstitial pneumonitis associated with gefitinib. CONCLUSION: Gefitinib showed favorable anti-tumor activity in females, never smokers and adenocarcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Establishment and characterization of amylase-producing lung adenocarcinoma cell line, IMEC-2.

BACKGROUND: Few studies have successfully established an amylase-producing lung cancer cell line or have examined its cytological, biochemical and biological features. PATIENTS AND METHODS: Cancer cells, isolated from pleural effusion using a gradient method, were cultivated. RESULTS: Amylase production from the newly established cell line was confirmed by positive staining for alpha-amylase and increased amylase levels in the culture supernatant. Electron microscopy revealed zymogen granule-like structures. Sialylation of salivary-type amylase was confirmed directly from the cell line by examining the neuraminidase sensitivity and amylase elution profile under high-performance liquid chromatography. Neither EGFR or KRAS mutation were found. CONCLUSION: This cell line offers a useful tool for analyzing the pathogenesis and pathophysiology of amylase-producing lung cancers. Moreover, it might be useful for probing the metastasis and invasiveness of lung cancer cells and for developing an early diagnostic method based on sialylated salivary-amylase production.

Adenocarcinoma↗
PubMedDate not supplied

Phase II study of carboplatin and weekly paclitaxel in advanced non-small cell lung cancer.

BACKGROUND: The optimal schedule of taxane administration has been an area of active interest in several clinical trials. PATIENTS AND METHODS: To evaluate the efficacy and toxicity of carboplatin and weekly paclitaxel combination chemotherapy, a phase II study was conducted for chemo-naïve, advanced non-small cell lung cancer (NSCLC) patients. Patients received paclitaxel 100 mg/m2 on days 1, 8 and 15, and carboplatin with the target dose of area under the curve of 6 on day 1 every 28 days. RESULTS: Forty patients were enrolled. Overall response rate and survival at one year by intent-to-treat analyses was 35% and 57.5%, respectively. The median survival time was 12.2 months. Twenty-two patients (56%) had grade 3 or greater neutropenia. Grade 3 sensory and motor neuropathy were seen in one patient (3%). CONCLUSION: Carboplatin and weekly paclitaxel combination chemotherapy is an active and feasible regimen for patients with advanced NSCLC.

Adult↗