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Masahiro Kami

Publications and source records attributed to Masahiro Kami.

80 records · Page 5Linked to original sources
PubMed2002

Impact of stem cell source and conditioning regimen on erythrocyte recovery kinetics after allogeneic haematopoietic stem cell transplantation from an ABO-incompatible donor.

We evaluated erythrocyte recovery in 121 allogeneic haematopoietic stem cell transplantation (HSCT) recipients. There were 35 major and minor ABO-incompatible transplants, respectively, including 10 bi-directionally ABO-incompatible transplants. The use of peripheral blood stem cells facilitated erythrocyte recovery, regardless of the presence or absence of major ABO-incompatibility, and was associated with a frequent detection of anti-host isohaemagglutin early after minor ABO-incompatible transplantation, which was not associated with clinically relevant haemolysis. The use of a reduced-intensity regimen combining a purine analogue and busulphan did not delay erythrocyte recovery after major ABO-incompatible transplantation, suggesting this regimen had a strong activity against host plasma cell.

ABO Blood-Group System↗
PubMed2002

Fatal airway obstruction caused by invasive aspergillosis of the thyroid gland.

Invasive aspergillosis is a common form of fungal infection in patients with hematological malignancies. Because Aspergillus species have angioinvasive properties, they frequently disseminate from the lung to a variety of organs via hematogenous spread. Extra-pulmonary involvement occurs at an advanced stage of invasive aspergillosis, and represents an ominous sign. However, few reports have been published on extra-pulmonary involvement in cases of aspergillosis. Its clinical features have not been fully clarified. We experienced a patient who developed thyrotoxicosis and fatal airway obstruction caused by invasive aspergillosis of the thyroid. A 26-year-old man was admitted to our hospital for the treatment of non-Hodgkin's lymphoma. During myelosuppression following the chemotherapy, he developed cervical swelling and hyperthyroidism. We suspected lymphoma infiltration to the thyroid, and irradiated it with a total of 26 Gy. However, the cervical lesion enlarged rapidly, and he complained of wheezing and dyspnea. We underwent immediate tracheostomy to secure the airway, but he died. Autopsy findings were striking. Extensive necrosis with diffuse infiltration of Aspergillus hyphae was observed in the thyroid gland. Necrotic tissues of the thyroid protruded into the tracheal lumen, causing airway obstruction. This case demonstrated that invasive aspergillosis of the thyroid can lead to medical emergency.

Adult↗
PubMed2002

Therapeutic potential of a reduced-intensity preparative regimen for allogeneic transplantation with cladribine, busulfan, and antithymocyte globulin against advanced/refractory acute leukemia/lymphoma.

PURPOSE: Cladribine (2-CdA) is a purine analogue that exhibits activity against a variety of hematological malignancies and has a potent immunosuppressive effect. We therefore performed a pilot study to evaluate the feasibility of a novel 2-CdA-based reduced-intensity stem cell transplantation (RIST) regimen. EXPERIMENTAL DESIGN: A total of 16 scheduled patients with hematological malignancies were enrolled for comparison of their data with conventional stem cell transplantation (n = 19). The regimen for RIST consisted of 2-CdA (0.11 mg/kg/day for 6 days), busulfan (4 mg/kg/day for 2 days), and rabbit antithymocyte globulin (2.5 mg/kg/day for 4, 2, or 0 days). The underlying diseases included acute myelogenous leukemia (n = 6), chronic myelogenous leukemia (n = 2), myelodysplastic syndrome (n = 6), and non-Hodgkin's lymphoma (n = 2). RESULTS: After RIST, four patients died before day 100 as a result of acute graft-versus-host disease (n = 1), bacteremia (n = 1), disseminated candidasis (n = 1) and congestive heart failure (n = 1). Another patient died of cerebral infarction on day 140. Thus, acute-phase regimen-related toxicities >grade III were observed in only one patient. Engraftment and complete donor chimerism were achieved by day 28 in 14 evaluable patients, and 6 of them (43%) experienced grade II-IV acute graft-versus-host disease. With a median follow-up of 328 days (range, 231-633 days), the actuarial 1-year overall and disease-free survival rates were 69% and 50%, respectively. Notably, among seven high-risk patients (five patients had been in complete remission two or more times and two not in complete remission with refractory disease at transplant), only two patients developed leukemia relapse after RIST. Although the recovery of CD4+ cells was significantly slower (P = 0.02) in RIST than in conventional stem cell transplantation, the incidence of clinically documented infections was not significantly different between the two groups. CONCLUSION: The results suggest that this novel regimen containing 2-CdA is well tolerated and induces early complete donor chimerism. The unexpected durable remission achieved in patients with advanced disease at transplant suggests the presence of an acceptable antileukemia/lymphoma effect, which would warrant a further clinical trial.

Adolescent↗
PubMed2002

[Efficiency of protective isolation in allogeneic stem cell transplantation in children].

Forty children with hematological malignancies, who underwent allogeneic hematopoietic stem cell transplants between September 1994 and May 2001, were divided into 2 groups according to their infection control procedure; the standard protective isolation and the efficient protective isolation groups. Efficient protective isolation procedures included well-cooked foods and oral prophylaxis with new quinolones and antifungal drugs, while inhalation of antibiotics and antifungal drugs was suspended. We then compared the febrile index (= X/Y) [febrile period (X) of > 38.5 degrees C and the days (Y) with a post-transplant neutrophil count < 500/microliter] between the two groups. We discovered no significant difference between the febrile index of the two groups (0.25 vs. 0.38, p = 0.08), regardless of the type of transplantation (0.36 vs. 0.38, p = 0.14). The efficient protective isolation procedure was therefore feasible in this clinical setting.

Adolescent↗
PubMedDate not supplied

Freeze-thawing procedures have no influence on the phenotypic and functional development of dendritic cells generated from peripheral blood CD14+ monocytes.

Little is known about the potential influence of cryopreservation on the biologic activities of dendritic cells (DCs). In this study, we examined the effects of freeze-thawing on the phenotypic and functional development of human DCs obtained from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood CD14+ cells. CD14+ cells were cultured, immediately or after freeze-thawing, with granulocyte-macrophage CSF and interleukin-4 for 9 days, and then with added tumor necrosis factor-alpha for another 3 days. For both fresh and freeze-thawed monocytes, immature DCs harvested on day 6 and mature DCs harvested on day 9 of culture were examined under the same conditions. Cells were compared with regard to their 1) capacities for antigen endocytosis and chemotactic migration (immature DCs), and 2) allogeneic mixed lymphocyte reaction and antigen-specific cytotoxic T lymphocyte responses (mature DCs). Freeze-thawing did not affect the viability or subsequent maturation of DCs at any stage of development. Furthermore, essentially no difference was observed in phenotype or function between cells generated from fresh or cryopreserved/thawed cells. Although this study design was limited with the use of fetal bovine serum, the observation still suggests that freeze-thawing does not affect viability, phenotype, subsequent maturation, or functions of DCs at any stage of maturation.

Cells, Cultured↗
PubMedDate not supplied

Expansion of alpha-galactosylceramide-stimulated Valpha24+ NKT cells cultured in the absence of animal materials.

Valpha24+ NKT is an innate lymphocyte with potential antitumor activity. Clinical applications of Valpha24+ natural killer (NK) T cells, which are innate lymphocytes with potential antitumor activity, require their in vitro expansion. To avoid the potential dangers posed to patients by fetal bovine serum (FBS), the authors evaluated non-FBS culture conditions for the selective and efficient expansion of human Valpha24+ NKT cells. Mononuclear cells (MNCs) and plasma from the peripheral blood of normal healthy donors were used before and after G-CSF mobilization. MNCs and plasma separated from apheresis products were also used. MNCs were cultured for 12 days in AIM-V medium containing alpha-galactosylceramide (alpha-GalCer) (100 ng/mL) and IL-2 (100 U/mL) supplemented with FBS, autologous plasma, or autologous serum. The cultured cells were collected and their surface markers, intracellular cytokines, and cytotoxicity were evaluated. The highest expansion ratio for Valpha24+ NKT cells was obtained from G-CSF-mobilized MNCs cultured in medium containing 5% autologous plasma. Cultures containing MNCs and autologous plasma obtained before and after G-CSF mobilization had approximately 350-fold and 2,000-fold expansion ratios, respectively. These results suggest that G-CSF mobilization conferred a proliferative advantage to Valpha24+ NKT cells by modifying the biology of cells and plasma factors. Expanded Valpha24+ NKT cells retained their surface antigen expression and production of IFN-gamma and exhibited CD1d-independent cytotoxicity against tumor cells. Valpha24+ NKT cells can be efficiently expanded from G-CSF-mobilized peripheral blood MNCs in non-FBS culture conditions with alpha-GalCer and IL-2.

Blood Component Removal↗