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Biomedical subjects

Shinichiro Okamoto

Publications and source records attributed to Shinichiro Okamoto.

At least 19 recordsLinked to original sources
PubMed2007

Risk factors for developing human herpesvirus 6 (HHV-6) reactivation after allogeneic hematopoietic stem cell transplantation and its association with central nervous system disorders.

We prospectively evaluated the incidence of human herpesvirus 6 (HHV-6) DNAemia after allogeneic hematopoietic stem cell transplantation (HSCT) using quantitative plasma real-time polymerase chain reaction. Of 46 recipients of bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT) from related (n = 11) or unrelated donors (n = 22), and cord blood transplantation (CBT) from unrelated donors (n = 13), 22 (47.8%) developed HHV-6 DNAemia. HHV-6 DNA levels ranged from 200 to 200,000 copies/mL of plasma, and HHV-6 DNAemia was observed significantly more frequently after CBT than after BMT/PBSCT (92.3% vs 30.3%; P < .001). Multivariate analyses identified CBT (vs BMT/PBSCT), HLA mismatches between recipient and donor, and low anti-HHV-6 IgG titer before transplantation as the only risk factors for developing HHV-6 DNAemia. Three patients developed central nervous system (CNS) disorders with detectable HHV-6 DNA in the cerebrospinal fluid; all of these patients simultaneously developed HHV-6 DNAemia. These results suggest that HHV-6 DNAemia is frequently observed after allogeneic HSCT, especially in patients with the aforementioned risk factors. Thus, together with the assessment of risk factors, monitoring of HHV-6 DNAemia could be a useful asset in diagnosing HHV-6-associated CNS disorders.

Adult↗
PubMed2006

Brief oral cryotherapy for the prevention of high-dose melphalan-induced stomatitis in allogeneic hematopoietic stem cell transplant recipients.

We previously reported the efficacy of oral cryotherapy for the prevention of high-dose melphalan-induced stomatitis. The purpose of this study was to evaluate whether the further shortening of the duration of oral cryotherapy could minimize its side effects while sparing its efficacy. Seventeen consecutive recipients of allogeneic hematopoieic stem cell transplant conditioned with high-dose melphalan in combination with fludarabine alone or with fludarabine and additional radiation were enrolled in the study. The severity of stomatitis was graded according to the National Cancer Institute-Common Toxicity Criteria. Patients were kept on oral cryotherapy shortly before, during, and for additional 30 min after the completion of melphalan administration (60-min oral cryotherapy). Patients who were also enrolled in our previous study received the same type of oral cryotherapy but for additional 90 min after the completion of melphalan administration (120-min oral cryotherapy), and they served as controls. Only 2 (11.8%) of 17 patients receiving 60-min oral cryotherapy and 2 (11.1%) of 18 patients receiving 120-min oral cryotherapy developed grade 2 or 3 stomatitis, respectively. The difference between groups was not statistically significant (P = 0.677). The incidence of unpleasant symptoms such as chills and nausea during oral cryotherapy decreased significantly with 60-min oral cryotherapy, as compared with that associated with 120-min oral cryotherapy (P < 0.01). These results suggest that 60-min oral cryotherapy is as effective as 120-min oral cryotherapy at preventing high-dose melphalan-induced stomatitis, and shorter treatment might have contributed to relieve patient discomfort during oral cryotherapy.

Administration, Oral↗
PubMed2006

Effect of blood cyclosporine concentration on the outcome of hematopoietic stem cell transplantation from an HLA-matched sibling donor.

We retrospectively evaluated the effect of the blood cyclosporine (CsA) concentration on the outcome of allogeneic hematopoietic stem cell transplantation from an HLA-matched sibling donor in 171 patients who received a continuous infusion of CsA and short-course methotrexate to prevent graft-versus-host disease (GVHD). CsA was started at 3.0 mg/kg/day and the dose was adjusted to maintain the blood CsA concentration between 250 and 350 ng/ml. The actual dose of CsA averaged 1.9 mg/kg/day at the 3rd week after transplantation. The incidence of grade II-IV acute GVHD was 29.9%. Patient age and sex were identified as independent significant risk factors for acute GVHD. The CsA concentration during the 3rd week after transplantation most strongly affected the incidence of grade II-IV acute GVHD (RR 0.995 for an increase in CsA concentration by 1 ng/ml, P = 0.037) adjusted for other risk factors. The incidence of acute GVHD was significantly lower in patients with a 3rd-week CsA concentration higher than 300 ng/ml than in those with values between 200 and 300 ng/ml (20% vs. 35%, P = 0.036). We concluded that the blood CsA concentration at peri-engraftment period may be important in preventing acute GVHD.

Cyclosporine↗
PubMed2006

Excretion of cytosine arabinoside in saliva after its administration at high doses.

High-dose cytosine arabinoside (cytarabine) is widely used, either alone or in combination with other chemotherapeutic agents, for the treatment of refractory hematological malignancies. Its pharmacology in plasma and cerebrospinal fluid has been extensively examined. In this study, we measured the concentration of cytarabine in saliva of nine patients with hematological malignancies who received high-dose cytarabine. Cytarabine at a dose of 3 g/m was administered i.v. over 2 h. Saliva samples were collected before initiating cytarabine infusion, within 15 min after the completion of infusion and 2 or 4 h after infusion. The concentration of cytarabine was measured by HPLC methods. All nine patients showed a detectable level of cytarabine in saliva within 15 min after the completion of infusion (0.58+/-0.48 microg/ml), which was equivalent to 5% of its plasma concentration; however, the drug was no longer detectable in saliva thereafter. These findings suggest that cytarabine is excreted in saliva during and shortly after its administration at a high dose.

Adult↗
PubMed2006

Possible involvement of allogeneic antigens recognised by donor-derived CD4 cytotoxic T cells in selective GVL effects after stem cell transplantation of patients with haematological malignancy.

Cytotoxic T lymphocyte (CTL) lines specific for allogeneic antigens were generated by in vitro stimulation of donor-derived peripheral blood mononuclear cells obtained from patients who received human leucocyte antigen (HLA)-matched allogeneic haematopoietic stem cell transplantation (HSCT). One of the allogeneic antigen-specific CD4+ CTL lines, CTL-A, generated from a patient with T cell acute lymphoblastic leukaemia, recognised HLA-DPB1*0501-positive Epstein-Barr virus-immortalised human B cell line (EBV-B cells), phytohaemagglutinin blasts and leukaemia cells, but not interferon-gamma (IFN-gamma) treated HLA-DPB1*0501-positive fibroblasts, indicating that this CD4+ T-cell line recognised a minor histocompatibility antigen (mHa) that is preferentially expressed in haematopoietic cells in an HLA-DPB1*0501-restricted manner. The other CD4+ CTL line, CTL-B, generated from a patient with chronic myeloid leukaemia, recognised mismatched HLA-DQB1*0303 on EBV-B cells and phytohaemagglutinin (PHA) blasts. Interestingly, this CTL line did not recognise IFN-gamma-treated recipient's skin fibroblasts, as HLA-DQ was merely upregulated even after IFN-gamma stimulation in non-haematopoietic cells including fibroblasts, endothelial cells and hepatocytes. These results suggest that these CD4 positive CTLs, specific for mismatch HLA-DQ and mHa that are preferentially expressed on haematopoietic cells, may play an important role in induction of selective graft-versus-leukaemia effect without development of graft-versus-host disease after allogeneic HSCT.

CD4-Positive T-Lymphocytes↗
PubMed2006

Unusual hemangioendothelioma of the liver with epithelioid morphology associated with marked eosinophilia: autopsy case.

Vascular neoplasms characterized by epithelioid endothelial cells consist of several different entities from benignity to high-grade malignancy. Because of histological overlap between them, there is substantial difficulty in classifying them correctly. The present patient, a 33-year-old man, presented with hepatomegaly, striking eosinophilia and elevated serum interleukin-5 level. Biopsy and autopsy revealed an unusual epithelioid vascular tumor in the liver, which is histologically distinct from epithelioid hemangioma, epithelioid hemangioendothelioma, or epithelioid angiosarcoma. The tumor cells had vasoformative and partly solid growth with no severe nuclear atypia and very low mitotic activity, and the histological features were similar to those of the entity recognized as hemangioendothelioma of bone. Organs other than the liver, for example the testes and bone, were also involved. This tumor should be considered in the differential diagnosis of severe eosinophilia.

Adult↗
PubMed2006

Ocular complications in a child with acute graft-versus-host disease following cord blood stem cell transplantation: therapeutic challenges.

We present the first child case of pseudomembranous conjunctivitis accompanied by an extensive corneal ulcer with acute graft-versus-host disease (GVHD) after cord blood stem cell transplantation (CBSCT). The histopathology of the pseudomembrane and the ocular changes following its excision were investigated specifically. One week after the excision of pseudomembrane, the extensive corneal epithelial defects had totally disappeared. Pseudomembrane excision may be an effective method of treatment in corneal epithelial defects observed after GVHD.

Acute Disease↗
PubMed2006

Current status of hematopoietic cell transplantation for adult patients with hematologic diseases and solid tumors in Japan.

A nationwide survey of hematopoietic cell transplantation (HCT) was started in Japan in 1991, and the analyzed survey data have been presented as the annual report of the Japan Society for Hematopoietic Cell Transplantation. The 10-year overall survival (OS) rates after HCT for each disease are as follows: acute myelogenous leukemia, 44.2%; acute lymphocytic leukemia, 33.7%; adult T-cell leukemia, 24.6%; chronic myelogenous leukemia, 53.3%; myelodysplastic syndrome, 37.3%; non-Hodgkin's lymphoma, 41.5%; Hodgkin's lymphoma, 50.8%; aplastic anemia, 72.5%; breast cancer, 37.1%; germ cell tumor, 52.6%; and ovarian cancer, 44.2%. The 5-year OS rates for multiple myeloma and lung cancer were 40.6% and 23.6%, respectively. Except in cord blood transplantation, engraftment was accomplished in more than 90% of patients. The respective frequencies of acute graft-versus-host disease (GVHD) and chronic GVHD were 41.1% and 34.9% for related bone marrow transplantation (BMT), 66.8% and 34.5% for unrelated BMT, 52.9% and 36.0% for allogeneic peripheral blood stem cell transplantation, and 53.3% and 32.1% for allogeneic cord blood transplantation. OS for each disease was analyzed by patient age, stem cell source, donor type, disease status, and disease type. These data provide objective and valuable information for hematologists as well as for patients who need HCT.

Adolescent↗
PubMed2006

Recurrence of autoimmune disease after autologous peripheral blood stem cell transplantation for multiple myeloma.

There have been a number of reports on the improvement of concomitant autoimmune disease (AID) after autologous hematopoietic stem cell transplantation (SCT) performed for hematologic malignancy. However, in some cases of hematologic malignancy with AID, exacerbation of AID after autologous SCT has been reported. We have treated 27 adults with multiple myeloma with single or tandem autologous SCT. After peripheral blood stem cells were collected and stored without CD34+ cell selection or T-cell depletion, all patients received melphalan (200 mg/m2) as a conditioning regimen. In 2 patients with a history of AID (one with rheumatoid arthritis [RA] and the other with bullous pemphigoid [BP]) and in 1 patient with Sjögren syndrome, AID recurred 7 to 12 months after autologous SCT. The RA and BP were in durable remission before SCT, and no Sjögren syndrome-related disease activity was clinically documented at the time of SCT. No progression of the myeloma was observed when the AIDs recurred. The patients required systemic steroid therapy for their AID, and successful control of the disease was achieved. Our experience suggests that autologous SCT with unmanipulated stem cells for myeloma is unlikely to cure preexisting AID; rather, the AID may worsen. Transplantation physicians should be aware of this possible complication.

Aged↗
PubMed2006

Human herpesvirus 6 meningoencephalitis in allogeneic hematopoietic stem cell transplant recipients.

We retrospectively investigated the clinical characteristics of human herpesvirus 6 (HHV-6) meningoencephalitis within 100 days after allogeneic hematopoietic stem cell transplantation (HSCT). Of 1148 patients who received transplants between January 1999 and December 2003, 11 patients (0.96%) with HHV-6 meningoencephalitis were identified. Ten of 11 recipients received hematopoietic stem cells from donors other than HLA-identical siblings. Confusion was the most frequent central nervous system (CNS) symptom, and a skin rash with high-grade fever preceded the CNS symptoms in 9 patients. Magnetic resonance imaging of the brain showed an abnormal increased T2 signal in the hypothalamus of 5 patients. Eight patients were treated with ganciclovir, and an improvement of CNS symptoms was obtained in 3 patients; 3 patients treated with acyclovir showed no improvement. Improvement in the meningoencephalitis seemed less frequent in patients with abnormal findings in the hypothalamus than in those without such findings. Because the symptoms of HHV-6 meningoencephalitis mimicked those of cyclosporine- or tacrolimus-induced encephalopathy, the drugs were withdrawn at the onset of CNS symptoms in 10 patients, resulting in the development of grade IV graft-versus-host disease (GVHD) in 5 patients. Three patients died of HHV-6 meningoencephalitis, and 6 died of other causes, including GVHD. In conclusion, HHV-6 meningoencephalitis is a rare but potentially life-threatening complication in patients who undergo allogeneic HSCT. Careful assessment of the clinical findings and the brain may allow early and precise diagnosis of HHV-6 meningoencephalitis and contribute to improving its prognosis.

Adolescent↗
PubMed2006

Prevention of cytomegalovirus infection by valaciclovir after allogeneic bone marrow transplantation from an unrelated donor.

In this prospective single-center study, we evaluated the efficacy and safety of valaciclovir (VACV) in the prevention of cytomegalovirus (CMV) infection after allogeneic bone marrow transplantation (BMT). The study population consisted of 12 patients who underwent allogeneic BMT from an unrelated donor. Patients received acyclovir (ACV) intravenously until they became able to take VACV orally. VACV was administered at a daily dose of 3000 mg and continued until day 100. CMV infection was monitored by CMV antigenemia assay and real-time polymerase chain reaction analysis of plasma. Thirty-five patients who did not receive any form of CMV chemoprophylaxis served as control subjects. CMV infection was detected in 4 (33.3%) of the 12 patients and in 24 (68.6%) of the 35 control subjects (P < .05). The onset of CMV infection was significantly delayed in the VACV group (median, day 43) compared with the control group (median, day 28.5; P < .01). Gastrointestinal symptoms as an adverse event due to VACV administration were observed in 2 patients. The plasma levels of ACV after VACV administration were measured in 8 patients and were similar to those in the healthy subjects. In conclusion, VACV shows normal absorption, even in the early posttransplantation period, and may prevent or delay CMV infection effectively and safely in allogeneic BMT recipients.

Acyclovir↗
PubMed2006

[Clinical analysis of the acute exacerbation in patients with idiopathic pulmonary fibrosis].

The clinical course of idiopathic pulmonary fibrosis (IPF) is chronic, but some patients with IPF have phases of accelerated deterioration superimposed on the chronic course of their illness, which is referred to as acute exacerbation (Aex) of IPF. To evaluate the clinical feature of Aex of IPF, we analyzed clinical findings of the 112 patients with IPF admitted to our hospital from 1994 to 2004. Of the 112 patients 56 with IPF died during the observation period due to Aex (42.9%), lung cancer (21.4%), chronic respiratory failure (14.3%), and lower respiratory infections (8.9%). Aex of IPF was seen 28 of 112 patients with IPF (25.0%) and 24 patients (85.7%) died with Aex. The median survival time (MST) after the onset of Aex was 0.9 months. The 5-yr survival rate of all patients with IPF was 38.3% and the MST was 3.1 yrs after diagnosis. On the other hand, the 5-yr survival rate and MST was 10.7% and 0.6 yrs in patients with Aex of IPF. We treated the patients with Aex with methylprednisolone pulse therapy in combination with cyclophosphamide or cyclosporine A, which did not significantly improve the outcome of Aex. In conclusion, there is little evidence that currently accepted treatments are effective in Aex of IPF, and further studies are needed to clarify the pathogenesis and contribute to the prevention of Aex.

Aged↗