Search PubMed⌕ Search

Biomedical subjects

Akira Yamada

Publications and source records attributed to Akira Yamada.

At least 37 records · Page 2Linked to original sources
PubMed2006

Fatal case of amiodarone-induced acute respiratory distress syndrome in a patient with severe left ventricular dysfunction due to extensive anterior acute myocardial infarction.

We here report a case of 71-year-old man with acute extensive anterior myocardial infarction, who was complicated with ventricular tachycardia (VT) even after successful percutaneous coronary intervention. As intravenous administration of nifekalant terminated VT, we started oral administration of amiodarone (day 1). We gave 400 mg of amiodarone a day for the first week and 200 mg a day from the second week. The patient was stable with normoxia by day 20, in spite of pulmonary congestion-like infiltrates on chest X-ray. On day 21, he was complicated with acute respiratory distress syndrome. Immediate discontinuance of amiodarone and high-dose pulse glucocorticoid therapy with intubation slightly improved the infiltrations on chest X-ray. However, glucocorticoid therapy induced hyperglycemia with an increase in plasma osmolality, complicated with hypoalbuminemia, and gastrointestinal bleeding. Despite treatment with a large amount of saline, high-doses of catecholamines, and blood transfusion, the patient died on day 28. It is sometimes difficult to diagnose congestive heart failure or amiodarone-induced pulmonary infiltrates in patients with severe left ventricular dysfunction.

Aged↗
PubMed2006

Anti-cancer vaccine candidates in specific immunotherapy for bladder carcinoma.

We have previously identified numerous tumor-rejection antigens and their epitope peptides having the potential to induce cancer-reactive cytotoxic T lymphocytes (CTLs) in patients with various types of cancer. In the present study, we attempted to determine which antigens and their peptides are useful in specific immunotherapy for bladder carcinoma (BC) patients, especially those with human leukocyte antigen (HLA)-A24+ alleles. The mRNA expression of a panel of cancer-associated antigens was examined regarding four BC cell lines. As a result, three candidate antigens, including SART3, multidrug resistance-associated protein 3 (MRP3), and polycomb group protein enhancer of zeste homolog 2 (EZH2), were expressed in three of four BC cell lines. Thereafter, antigen-derived peptides which we reported to induce cancer-reactive CTLs from HLA-A24+ patients with various types of cancer were examined for their potential to induce CTLs from peripheral-blood mononuclear cells of HLA-A24+ BC patients. Among these antigen-derived six peptides, SART3109-118, MRP31293-1301, and EZH2735-742 peptides efficiently induced peptide-specific and BC cell-reactive CTLs from HLA-A24+ BC patients. The cytotoxicity against BC cells was dependent on peptide-specific CD8+ T cells. IgG reactive to the SART3109-118 peptide was frequently detected in the plasma of BC patients. This information could facilitate the development of effective peptide-based immunotherapy for HLA-A24+ BC patients.

Antigens, Neoplasm↗
PubMed2006

[Acquired tumor "robustness" in the case of prostate cancer].

Tumors are highly robust and maintain their proliferative potential against both a wide range of host-defense mechanisms and anticancer therapies. In this study, we investigated the levels of human leukocyte antigen (HLA) class I, multi-drug resistance 1 (MDR1), and androgen receptor (AR) expressions in untreated prostate cancers harvested by radical prostectomy. The mean percentages of cancer cells expressing HLA class I, MDR1, and AR among the 10 cancer samples were 41, 35, and 74%, respectively. In addition, double-staining of HLA class I and MDR1 revealed the four definite populations (HLA class I(+)/MDR(+), HLA class I(+)/MDR(-), HLA class I (-)/MDR(+), and HLA class I(-)/MDR(-)) in cancer tissues from the majority of cancer patients tested, and the mean percentages of cells expressing these combinations were 13, 29, 22, and 38%, respectively. Similar results were obtained by double staining of HLA class I and AR, except for 2 cases in which HLA class I(-)/AR (+) cancer cells predominated. These results indicated that untreated prostate cancer cells acquired a wide range of genomic mutation, which may have been caused by internal host pressure to eliminate malignant cells, and would provide evidence of the robustness of untreated prostate cancer.

Aged↗
PubMed2005

Cardiac sympathetic dysfunction correlates with abnormal myocardial contractile reserve in dilated cardiomyopathy patients.

OBJECTIVES: We investigated the relationship between iodine-123-metaiodobenzylguanidine (123I-MIBG) findings and myocardial contractile reserve in patients with mild to moderate dilated cardiomyopathy (DCM). BACKGROUND: Little is known regarding the relationship between cardiac sympathetic nervous function and myocardial contractile reserve in DCM. METHODS: Twenty-four DCM patients who showed sinus rhythm underwent echocardiography, biventricular catheterization, and myocardial 123I-MIBG scintigraphy. Left ventricular (LV) pressures were measured using a micromanometer-tipped catheter. The myocardial contractile function (LV dP/dt(max)) was determined at rest and during atrial pacing. The messenger ribonucleic acid (mRNA) expressions of intracellular Ca2+-regulatory proteins were analyzed by real-time quantitative reverse transcription-polymerase chain reaction. Myocardial 123I-MIBG accumulation was quantified as a heart-mediastinum ratio (HMR). RESULTS: A significant correlation was observed between the delayed 123I-MIBG HMR and the percentage change in LV dP/dt(max) from the baseline to the peak or critical heart rate (r = 0.64; p < 0.001). The delayed 123I-MIBG HMR was significantly lower in patients showing a worsening change in LV dP/dt(max) than in those showing a favorable change (p < 0.005). The maximum LV dP/dt(max) during pacing and the sarcoplasmic reticulum Ca2+-ATPase (SERCA2) mRNA levels were significantly more reduced in patients with a delayed HMR < or =1.8 than in those with a delayed HMR >1.8 (p < 0.05, respectively). CONCLUSIONS: Abnormal myocardial 123I-MIBG accumulation is related to an impaired myocardial contractile reserve and down-regulation of SERCA2 mRNA in DCM. Myocardial 123I-MIBG scintigraphy can be useful in noninvasively evaluating myocardial contractile reserve in patients with mild to moderate DCM.

3-Iodobenzylguanidine↗
PubMed2005

Requirements for induction and maintenance of peripheral tolerance in stringent allograft models.

Peripheral tolerance can be achieved in many but not all murine allograft models. The requirements for controlling more aggressive immune responsiveness and generating peripheral tolerance in stringent allograft models are unknown. Understanding these requirements will provide insight toward ultimately achieving tolerance in humans, which are also resistant. We now demonstrate that the combination of donor-specific transfusion, anti-CD45RB, and anti-CD154 uniformly achieves >90-d survival of BALB/c skin allografts on C57BL/6 recipients. Recipients exhibit marked hyporesponsiveness to alloantigen in vitro. In distinct contrast to less rigorous models, engraftment remains absolutely dependent on cytotoxic T lymphocyte antigen 4 signaling, even after grafts are healed, suggesting that prolonged engraftment cannot simply be attributed to more effective depletion of alloreactive T cells but is actively maintained by regulation. Concordantly, we show that both CD4 and CD8 regulatory cells are required and can transfer donor-specific tolerance to naïve recipients. Nonetheless, most recipients ultimately develop gradual graft loss (median survival time = 140 d), suggesting that alloreactive cells emerging from the thymus eventually overwhelm regulatory capacity. In agreement, adding thymectomy to the regimen results in permanent engraftment (>250 d) and donor-specific tolerance not observed previously in this model. These results highlight the potency of both CD4 and CD8 regulatory cells but also suggest that in stringent settings, regulatory T cell longevity and capacity for infectious tolerance compete with prolonged graft immunogenicity and thymic output. These results provide insight into the mechanisms of tolerance in stringent models and provide a rational basis for innovative tolerogenic strategies in humans.

Animals↗
PubMed2005

Immunologic evaluation of personalized peptide vaccination for patients with advanced malignant glioma.

PURPOSE: The primary goal of this phase I study was to assess the safety and immunologic responses of personalized peptide vaccination for patients with advanced malignant glioma. EXPERIMENTAL DESIGN: Twenty-five patients with advanced malignant glioma (8 grade 3 and 17 grade 4 gliomas) were evaluated in a phase I clinical study of a personalized peptide vaccination. For personalized peptide vaccination, prevaccination peripheral blood mononuclear cells and plasma were provided to examine cellular and humoral responses to 25 or 23 peptides in HLA-A24+ or HLA-A2+ patients, respectively; then, only the reactive peptides (maximum of four) were used for in vivo administration. RESULTS: The protocols were well tolerated with local redness and swelling at the injection site in most cases. Twenty-one patients received more than six vaccinations and were evaluated for both immunologic and clinical responses. Increases in cellular or humoral responses specific to at least one of the vaccinated peptides were observed in the postvaccination (sixth) samples from 14 or 11 of 21 patients, respectively. More importantly, significant levels of peptide-specific IgG were detected in the postvaccination tumor cavity or spinal fluid of all of the tested patients who showed favorable clinical responses. Clinical responses were 5 partial responses, 8 cases of stable disease, and 8 cases of progressive disease. The median overall survival for patients with recurrent glioblastoma multiforme in this study (n = 17) was 622 days. CONCLUSIONS: Personalized peptide vaccinations were recommended for the further clinical study to malignant glioma patients.

Adult↗
PubMed2005

Identification of hepatitis C virus 1b-derived peptides recognized by both cellular and humoral immune systems in HCV1b(+) HLA-A24(+) patients.

Despite scientific advances, the therapeutic options for hepatitis C virus (HCV) are limited by poor response rates. HCV1b is particularly resistant to standard interferon therapy. The inhibition of the progression of chronic hepatitis and liver cirrhosis and the prevention of the occurrence and recurrence of hepatocellular carcinoma (HCC) are important and thus, there is a need for new therapeutic modalities for HCV1b infection. We, therefore, investigated highly immunogenic peptides and report in this study three novel candidate peptides (at positions 711-720 in envelope 2 protein, 885-893 in non-structural protein 2 and 1716-1724 in non-structural protein 4B) among 35 peptides of conserved regions of HCV1b proteins containing HLA-A24 binding motifs tested. Namely, HCV(711-720), HCV(885-893) and HCV(1716-1724) induced HLA-A24-restricted and peptide-specific cytotoxic T lymphocytes (CTLs) activity in peripheral blood mononuclear cells (PBMCs) from 7, 6 and 5 of 12 patients and also were recognized by plasma of 8, 5 and 7 of 12 HCV1b(+) patients, respectively. These results may provide new insight into the development of a peptide-based specific immunotherapy for HCV1b(+) HLA-A24(+) patients.

Journal Article↗
PubMed2005

Immunological evaluation of individualized peptide vaccination with a low dose of estramustine for HLA-A24+ HRPC patients.

BACKGROUND: The safety, toxicity, and immunological response of individualized peptide vaccination or human leukocyte antigen (HLA)-A24+ hormone refractory prostate cancer (HRPC) patients in combination with a low dose of estramustine were evaluated. METHODS: Sixteen patients with HLA-A24+ HRPC were enrolled in the phase I/II study. Conducted immune monitorings for those patients were peptide-specific cytotoxic T lymphocyte (CTL) precursor analysis by interferon-gamma production and peptide-reactive immunoglobulin G (IgG) by an enzyme-linked immunosorbent assay. Clinical responses and quality of life (QOL) outcomes using a self-reported patient questionnaire were also evaluated. RESULTS: Vaccinations were well tolerated, but all patients developed grade 1 or 2 local redness and swelling at the injection site. There was no significant immunosuppression in most cases when the peptide and a half dose (280 mg/day) of estramustine were administrated. Augmentation of peptide-specific CTL precursors or peptide-specific IgG was observed in 10 of 14 or 7 of 14 patients at 12 weeks (peptide vaccination alone), and in 6 of 8 or 10 of 12 patients at 24 weeks (during the combination therapy), respectively. All 13 patients treated, with the combination therapy, showed a decrease of serum prostate-specific antigen (PSA) level from the baseline, including six patients with a serum PSA level decrease of >or=50%. QOL outcomes were not deteriorated during the treatment. CONCLUSION: These results might encourage the further evaluation of the combination of peptide vaccination and a low dose of estramustine phosphate for HLA-A24+ HRPC patients.

Aged↗
PubMed2005

CD70 signaling is critical for CD28-independent CD8+ T cell-mediated alloimmune responses in vivo.

The inability to reproducibly induce robust and durable transplant tolerance using CD28-B7 pathway blockade is in part related to the persistence of alloreactive effector/memory CD8(+) T cells that are less dependent on this pathway for their cellular activation. We studied the role of the novel T cell costimulatory pathway, CD27-CD70, in alloimmunity in the presence and absence of CD28-B7 signaling. CD70 blockade prolonged survival of fully mismatched vascularized cardiac allografts in wild-type murine recipients, and in CD28-deficient mice induced long-term survival while significantly preventing the development of chronic allograft vasculopathy. CD70 blockade had little effect on CD4(+) T cell function but prevented CD8(+) T cell-mediated rejection, inhibited the proliferation and activation of effector CD8(+) T cells, and diminished the expansion of effector and memory CD8(+) T cells in vivo. Thus, the CD27-CD70 pathway is critical for CD28-independent effector/memory CD8(+) alloreactive T cell activation in vivo. These novel findings have important implications for the development of transplantation tolerance-inducing strategies in primates and humans, in which CD8(+) T cell depletion is currently mandatory.

Acute Disease↗
PubMed2005

Concurrent occurrence of allergic granulomatous angiitis and temporal arteritis: a case report and review of the literature.

Allergic granulomatous angiitis (AGA) is a disease entity that was first distinguished from classical polyarteritis nodosa by Churg and Strauss in 1951, and is characterized by the clinical features of allergic rhinitis or bronchial asthma, eosinophilia, and vasculitis. Allergic granulomatous angiitis has been described to mainly involve small vessels. We herein describe a case of Churg-Strauss syndrome which demonstrated the clinical and laboratory findings supporting a diagnosis of AGA and was also associated with the clinical and pathological findings for temporal arteritis, which was characterized by eosinophil infiltration and granuloma formation of the temporal artery (middle-sized vessel).

Journal Article↗
PubMed2005

Twitchin purified from molluscan catch muscles regulates interactions between actin and myosin filaments at rest in a phosphorylation-dependent manner.

Twitchin, also called mini-titin, is structurally related to the giant elastic protein connectin/titin, and has been found in not only striated but also smooth muscles of bivalves. Many bivalve smooth muscles such as byssus retractor muscles and the opaque part of adductor muscles are known as catch muscles that can maintain high passive tension with little expenditure of energy after they have actively contracted. Twitchin is phosphorylated when this high-tension state (catch state) ceases. Our recent studies revealed that the catch tension is due to interactions between thick and thin filaments in the presence of MgATP at low free Ca2+ concentrations, which can be visualized in vitro under a light microscope (Yamada et al., 2001 Proc Natl Acad Sci USA 98: 6635-6640). We also found that twitchin is essential for the interactions of the catch state in mussel (Mytilus galloprovincialis) catch muscles. In the presence of twitchin, actin filaments bound to purified myosin filaments when twitchin was dephosphorylated by Ser/Thr protein phosphatase 2B, while they did not when it was phosphorylated by cAMP-dependent protein kinase. In the current study we demonstrate the same essential components of the catch state for another bivalve that exhibits catch, i.e., Japanese oyster (Crassostrea gigas).

Actins↗
PubMed2005

Cranial distraction for plagiocephaly: quantitative morphologic analyses of cranium using three-dimensional computed tomography and a life-size model.

The aim of this study was to analyze the morphologic changes of the craniofacial skeleton in synostotic plagiocephaly after cranial distraction. Preoperative and postoperative computed tomography scans were taken, and three-dimensional reconstruction was then performed. Three measurements were obtained: intracranial volume, volume of the middle cranial fossa, and length of the zygomatic arch. Intracranial volume reached values that were normal for a 2-year-old child postoperatively, and the discrepancy between left and right half volumes decreased over time. The discrepancy of the volume of the middle cranial fossa also decreased after surgery, and the asymmetry of the zygomatic arch improved significantly. Based on these objective findings, the authors believe that cranial distraction could favorably affect craniofacial dysmorphology of synostotic frontal plagiocephaly.

Brain↗
PubMed2005

Immunological evaluation of personalized peptide vaccination for patients with pancreatic cancer.

The prognosis of pancreatic cancer is extremely poor, and development of new treatment modalities is needed. One such treatment could be specific immunotherapy. To evaluate safety and immunological responses, we conducted a phase I study of personalized peptide vaccination for pancreatic cancer patients (n=11). Namely, pre-vaccination peripheral blood mononuclear cells were screened for their reactivity in vitro to each of 14 or 16 peptides in HLA-A24(+) or -A2(+) patients, and only the reactive peptides (maximum: 4) were vaccinated in vivo. This regimen was generally well tolerated, although inflammatory reactions at the injection site were observed in 7 patients. Delayed-type hypersensitivity to peptides used for vaccination was observed in 7 patients. Increased cellular and humoral immune responses to at least one of peptides used for vaccination were observed in the post-vaccination PBMCs and sera from 4 of 8 patients and 4 of 10 patients tested, respectively. The 6- and 12-month survival rates for patients who received >3 vaccinations (n=10) were 80% and 20%, respectively. Due to tolerability and capability of inducing specific immunity, further development of personalized peptide-based immunotherapy for pancreatic cancer patients is warranted.

Aged↗
PubMed2005

Immunological evaluation of vaccination of peptides derived from epithelial cancer-related antigens in two patients with hematological malignancy.

Recent advances in tumor immunology have resulted in identification of many epithelial cancer-related antigens and peptides applicable to specific immunotherapy. We and others have reported that several epithelial cancer-related antigens are also expressed in hematological malignancies. Two patients with hematological malignancy (multiple myeloma and chronic lymphocytic leukemia) were vaccinated with peptides derived from epithelial cancer-related antigens to evaluate the immune responses to peptides under a personalized peptide vaccination regimen. There was no adverse event except for local skin reaction at the injection site. The peptide vaccination augmented both peptide-specific CTLs cytotoxic to hematological malignant cells in post-vaccination peripheral blood mononuclear cells and peptide-specific IgG in post-vaccination sera. A transient but obvious decrease of malignant cells was observed at the early phase of the vaccination in both cases. Vaccines consisting of peptides derived from epithelial cancer antigens safely increased anti-tumor cell activity in patients with hematological malignancies. These results may provide a scientific rationale in use of epithelial cancer-related antigens for specific immunotherapy to patients with hematological malignancies.

Aged↗
PubMed2005

[Anti-GBM disease].

Explore the source record for details and available documents.

Anti-Glomerular Basement Membrane Disease↗