Biomedical subjects

Rumi Gohara

Publications and source records attributed to Rumi Gohara.

10 recordsLinked to original sources

PubMed2004

Morphological analysis of glutaraldehyde-fixed vimentin intermediate filaments and assembly-intermediates by atomic force microscopy.

Atomic force microscopy (AFM) was used to study the morphology of vimentin intermediate filaments (IFs) and their assembly intermediates. At each time after initiation of IF assembly in vitro of recombinant mouse vimentin, the sample was fixed with 0.1% glutaraldehyde and then applied to AFM analysis. When mature vimentin IFs were imaged in air on mica, they appeared to have a width of approximately 28 nm, a height of approximately 4 nm and a length of several micrometers. Taking into account the probe tip's distortion effect, the exact width was evaluated to be approximately 25 nm, suggesting that the filaments flatten on the substrate rather than be cylindrical with a diameter of approximately 10 nm. Vimentin IFs in air clearly demonstrated approximately 21-nm repeating patterns along the filament axis. The three-dimensional profiles of vimentin IFs indicated that the characteristic patterns were presented by repeating segments with a convex surface. The repeating patterns close to 21 nm were also observed by AFM analysis in a physiological solution condition, suggesting that the segments along the filaments are an intrinsic substructure of vimentin IFs. In the course of IF assembly, assembly intermediates were analyzed in air. Many short filaments with a full-width and an apparent length of approximately 78 nm (evaluated length approximately 69 nm) were observed immediately after initiation of the assembly reaction. Interestingly, the short full-width filaments appeared to be composed of the four segments. Further incubation enabled the short full-width filaments to anneal longitudinally into longer filaments with a distinct elongation step of approximately 40 nm, which corresponds to the length of the two segments. To explain these observations, we propose a vimentin IF formation model in which vimentin dimers are supercoiling around the filament axis.

Animals↗

PubMed2004

In vivo evidence that peptide vaccination can induce HLA-DR-restricted CD4+ T cells reactive to a class I tumor peptide.

Vaccination with class I tumor peptides has been performed to induce tumor-reactive CD8(+) T cells in vivo. However, the kinds of immune responses that vaccination might elicit in patients are not fully understood. In this study we tried to elucidate the mechanisms by which vaccination of class I binding tumor peptides into an HLA-A2(+) lung cancer patient elicited dramatic amounts of IgG1 and IgG2 specific to a nonamer peptide, ubiquitin-conjugated enzyme variant Kua (UBE2V)(43-51). The UBE2V(43-51) peptide contains cysteine at the sixth position. HLA-DR-restricted and UBE2V(43-51) peptide-recognizing CD4(+) T cells were induced from postvaccination, but not from prevaccination, PBMCs of the cancer patient. In addition, a CD4(+) T cell line (UB-2) and its clone (UB-2.3), both of which recognize the UBE2V(43-51) peptide in the context of HLA-DRB1*0403 molecules, were successfully established from postvaccination PBMCs. The peptide vaccination increased the frequency of peptide-specific T cells, especially CD4(+) T cells. In contrast, mass spectrometric analysis revealed that the vaccinated UBE2V(43-51) peptide contained both monomeric and dimeric forms. Both forms, fractionated by reverse phase HPLC, were recognized by UB-2 and UB-2.3 cells. Recognition by these CD4(+) T cells was observed despite the addition of a reduction reagent or the fixation of APC. Overall, these results indicate that vaccination with class I tumor peptides can induce HLA-DR-restricted CD4(+) T cells in vivo and elicit humoral immune responses, and that a cysteine-containing peptide can be recognized by CD4(+) T cells not only as a monomer, but also as a dimer.

Aged↗

PubMed2003

Phase II study of irinotecan and ifosfamide in patients with advanced non-small cell lung cancer.

OBJECTIVES: This phase II study was conducted to investigate the efficacy and safety of irinotecan (CPT-11) and ifosfamide as first-line chemotherapy for advanced non-small cell lung cancer (NSCLC). METHODS: Eligibility criteria included histologically or cytologically confirmed NSCLC (stage IIIb or IV), no prior treatment, and measurable or evaluable disease. CPT-11 (80 mg/m(2)) was administered intravenously on days 1, 8, and 15, while ifosfamide (1.5 g/m(2)) was given on days 1 through 3 every 4 weeks. RESULTS: Forty-four patients (31 men) with a median age of 65 years (range 43-75) and a median ECOG performance status of 1 (range 0-2) were enrolled. The response rate was 29.5% [95% CI: 16.7-45.2%], with 13 partial responses. The median survival was 12.5 months, the median time to progression was 5.3 months, and the 1 and 2-year survival rates were 52.3 and 11.3%, respectively. Toxicity was generally mild; WHO grade 3-4 neutropenia was recorded in 38.6% of the patients, grade 3 diarrhea in 6.8%, and grade 3-4 nausea/vomiting in 0%. CONCLUSIONS: CPT-11 combined with ifosfamide demonstrated anti-tumor activity in advanced NSCLC, with response and survival rates similar to those of cisplatin-based chemotherapy but with a more favorable toxicity profile.

Adult↗

PubMed2003

Combination chemotherapy with irinotecan and ifosfamide as second-line treatment of refractory or sensitive relapsed small cell lung cancer: a phase II study.

This phase II study was conducted to investigate the efficacy and safety of irinotecan (CPT-11) and ifosfamide as second-line chemotherapy for relapsed small cell lung cancer (SCLC). Eligibility criteria included histologically or cytologically confirmed SCLC, prior chemotherapy including platinum + etoposide, and measurable or evaluable disease. CPT-11 (80 mg/m(2)) was administered intravenously on days 1, 8 and 15, while ifosfamide (1.5 g/m(2)) was given on days 1 through 3 every 4 weeks. Thirty-four patients (29 men) with a median age of 69 years (range 42-77) and a median Eastern Cooperative Oncology Group (ECOG) performance status of 1 (range 0-2) were enrolled. The response rate was 52.9% (95% confidence interval: 29.8-64.9%) with 2 complete responses and 16 partial responses. Our analyses of prognostic factors showed risk factors assessed before receiving second-line chemotherapy, which were the number of metastatic sites, performance status and the type of relapse. WHO grade 3-4 neutropenia was recorded in 52.9% of the patients, grade 3 diarrhea in 5.9%. The combination of CPT-11 and ifosfamide demonstrated clinical efficacy in relapsed SCLC with a favorable toxicity profile, particularly for performance status 0-1 and sensitive cases with only one metastatic site.

Adult↗

PubMed2003

Visualization of pulmonary arteriovenous malformation by three dimensional computed tomography: a case report.

Pulmonary arteriovenous malformation (PAVM) is an anomaly condition characterized by abnormal vascular communications between arteries and veins in the lungs. Hereby we describe a 60-year-old female with PAVM. Although the patient was asymptomatic, an abnormal round opacity was found on a chest X-ray film. Computed tomography (CT) of the lung disclosed nodules connected with enlarged vessels. Because PAVM was suspected, the patient was further evaluated by spiral CT coupled with three dimensional reconstruction of the images (3D-CT). As a result, PAVM was clearly visualized and invasive procedures such as angiography was not performed. The present case illustrates that 3D-CT is a diagnostic procedure of choice when PAVM is suspected.

Arteriovenous Fistula↗

PubMed2003

[Tuberculosis in elderly].

We compared patients with active tuberculosis treated at Kurume University Hospital between cases 65 years and above and below 65. The comparison included immunologic and clinical features. Anergy to tuberculin skin tests with purified protein derivative (PPD) was evident in 7% of patients under 65 and in 14% of those over 65. Older patients had fewer lymphocytes in peripheral blood and lower serum concentrations of interferon (IFN)-gamma than younger patients. Complications were more frequently seen in patients above 65, but the time required for negative conversion of sputum cultures did not differ by age. Adequacy of the regimen of chemotherapy and the sensitivity to anti-mycobacterial drugs were the most important determinants of the time for negative conversion of sputum culture. Major clinical problems of old tuberculosis patients were concurrent diseases, bed ridden states, necessity of nursing care, and poor performance status of patients.

Aged↗

PubMed2003

[Tuberculosis in patients undergoing hemodialysis].

We studied patients who were diagnosed as active tuberculosis while undergoing hemodialysis at Kurume University Hospital. The observation included immunologic and clinical features. Cellular immunity was depressed in our patients undergoing hemodialysis, as evident from the decreased numbers of lymphocytes and anergy to tuberculin skin tests with purified protein derivative (PPD). Further, in a few patients, hemodialysis was shown to eliminate IFN-gamma from the blood. Various antituberculous chemotherapy regimens have been studied in hemodialysis patients. Although the incidence and mortality of tuberculosis have been reported to be higher in hemodialysis patients than in the general population, the clinical outcome of our cases was favorable in this study. One important notice is to recognize promptly peripheral neuropathy while treating tuberculosis associated with hemodialysis, and this could be prevented by the adequate use of pyridoxine.

Adult↗

PubMed2002

[Phase I study of biweekly paclitaxel and carboplatin administration in patients with advanced non-small cell lung cancer].

A phase I study of a biweekly outpatient regimen composed of carboplatin (CBDCA) and paclitaxel (TXL) was conducted for advanced non-small cell lung cancer. TXL was given in combination with a fixed dose of CBDCA (AUC 3) every 2 weeks. The starting dose of TXL was 100 mg/m2, and the dose was escalated in increments of 20 mg/m2. Three to six patients were allocated to each level. Toxicities were evaluated in the first 4 courses to determine the maximum tolerated dose (MTD). TXL 160 mg/m2 dosages proved to be MTD, and the dose limiting toxicity (DLT) was hematotoxicity (neutropenia). The patients, however, recovered from neutropenia using G-CSF immediately, when G-CSF was used. Gastrointestinal toxicity was well-tolerated. A response was found in 9 out of 20 patients who received 4 courses or more (45%). These results suggest that the recommended dose would be CBDCA (AUC 3) + TXL 140 mg/m2. The biweekly regimen has a high level clinical activity and excellent tolerability, and is suitable for outpatients. We started a phase II study because of these results.

Adult↗

PubMedDate not supplied

Phase 1 clinical study of cyclophilin B peptide vaccine for patients with lung cancer.

Cyclophilin B (CypB) possesses two antigenic epitopes (CypB(84-92) and CypB(91-99) ) recognized by HLA-A24-restricted and tumor-specific cytotoxic T lymphocytes (CTLs). To determine the safety of CypB-derived peptides and its ability to generate antitumor immune responses, patients with advanced lung cancer received subcutaneous vaccinations of these peptides or their modified peptides. All 16 patients were vaccinated with CypB(91-99) or its modified peptide, whereas only two patients were vaccinated with the modified CypB(84-92), as immediate-type hypersensitivity to CypB(84-92) or its modified peptide was observed in the remaining patients. No severe adverse events were associated with the vaccination. No significant increase in cellular responses to either peptides or tumor cells was observed in the postvaccination PBMCs by the conventional CTL assays in any patients tested. These results suggest that the vaccination of CypB(91-99) peptide was safe, but failed to induce objective immune responses at this regimen.

Adult↗

PubMedDate not supplied

Peptide vaccination for patients with melanoma and other types of cancer based on pre-existing peptide-specific ctotoxic T-lymphocyte precursors in the periphery.

Identification of antigenic peptides expressed on cancer cells enables us to treat cancer patients with peptide-based immunotherapy. Although optimal protocols for peptide-based vaccines have not yet been elucidated, boosting the immune system could be a better approach than priming the immune system to elicit prompt and potent peptide-specific T-cell responses in cancer patients. With this possibility in mind, the authors undertook a clinical trial in which cancer patients were vaccinated with peptides (maximum 4) after confirmation of pre-existing peptide-specific cytotoxic T-lymphocyte (CTL) precursors in the periphery. Fourteen patients (seven with melanoma and seven with other types of cancer) positive for either HLA-A24 or HLA-A2 were enrolled in this study. Fourteen and 16 peptides were used to screen for HLA-A24+ and HLA-A2+ patients, respectively. The vaccination was well tolerated, and the only adverse effects were local pain and fever. Kinetic analysis revealed that peptide-reactive CTLs increased after peptide vaccination in 7 of 14 patients. Immunoglobulin G (IgG) reactive to the administered peptides was detected in 2 patients before vaccination, although it became detectable in 8 of the other 12 patients after the peptide vaccination. Stable disease for more than 6 months was observed in five patients (one with melanoma and four with other types of cancer); all of these patients showed increased levels of peptide-specific IgG. These results indicate that peptide vaccination of patients showing evidence of pre-existing peptide-specific CTL precursors can be applied in further clinical trials aimed at the treatment of melanoma and other types of cancer.

Adult↗