Biomedical subjects

Shigeru Tsuchiya

Publications and source records attributed to Shigeru Tsuchiya.

6 recordsLinked to original sources

PubMed2003

Novel Artemis gene mutations of radiosensitive severe combined immunodeficiency in Japanese families.

A subgroup of patients with severe combined immunodeficiency (SCID) and increased cellular radiation sensitivity (RS-SCID) have mutations of Artemis, a gene that encodes a protein essential for V(D)J recombination and DNA double-strand break repair. RS-SCID described to date are either of European origin or are Athabascan-speaking native Americans belonging to the Navajo and Apache tribes. We have identified three Japanese boys and one girl from four unrelated families with RS-SCID caused by a genomic exon 3 deletion of the Artemis gene, resulting in loss of exon 3 and skipping of exon 4. Two patients were homozygous and two patients were heterozygous for this novel mutation. Those parents studied were heterozygous for this mutation. These findings suggest the genomic exon 3 deletion is unique to Japan and may be considered as a founder haplotype. Although two infants underwent successful bone marrow transplantation and immune reconstitution, the long-term outcome of this procedure is uncertain, because Artemis is expressed in most tissues and lack of its function in cells other than those derived from hematopoietic stem cells may increase the risk of malignancies.

Antigens, CD↗

PubMed2003

Prognostic factors for chronic active Epstein-Barr virus infection.

Chronic active Epstein-Barr virus infection (CAEBV) is a high-mortality and high-morbidity disease. To clarify the prognostic factors, a national survey was performed in Japan, and data for 82 patients who met the criteria for CAEBV were analyzed. Of these 82 patients, 47 were alive and 35 had already died. Multivariate analysis revealed that thromobocytopenia and age at disease onset were correlated with mortality. The probability of 5-year survival was 0.45 for older patients (onset age, > or = 8 years), 0.94 for younger patients (P<.001), 0.38 for patients with thrombocytopenia (platelet count < 12 x 10(4) platelets/microL at diagnosis), and 0.76 for patients without thrombocytopenia (P=.01). Furthermore, patients with T cell infection by EBV had shorter survival times than patients with natural killer cell infection (probability of 5-year survival, 0.59 vs. 0.87; P<.009). Patients with CAEBV with late onset of disease, thrombocytopenia, and T cell infection had significantly poorer outcomes.

Adolescent↗

PubMed2003

A simple controlled-rate freezing method without a rate-controlled programmed freezer provides optimal conditions for both large-scale and small-scale cryopreservation of umbilical cord blood cells.

BACKGROUND: Umbilical cord blood (CB) is being used as a source of alternative HPCs for transplantation with increasing frequency. The goal of CB banks for unrelated transplantation is to provide good quality-controlled CB units that can be transplanted for HPCs into the largest possible number of patients. STUDY DESIGN AND METHODS: Large CB samples in freezing bags wrapped with insulators and small samples in cryotubes placed into double styrene-foam boxes were cryopreserved at -85 degrees C without a rate-controlled freezing machine, followed by storage in the liquid phase of nitrogen. After thawing these cells, the viability and recovery of cells, as well as the recovery rate of HPCs such as CD34+ cells, CFU-GM, and total CFU were evaluated. RESULTS: Measurement of the freezing rate in CB bags and cryotubes demonstrated that this simple method for cryopreservation of CB cells provided optimal conditions for both large-scale and small-scale cryopreservation. Recovery of CB progenitor cells after cryopreservation was also shown to be potentially acceptable when evaluated with CD34+ cells, CFU-GM, and total CFU. These results were comparable to the method using a rate-controlled programmed freezer. CONCLUSIONS: A simple method for cryopreservation of CB cells without a rate-controlled programmed freezer could provide a sufficient-enough potential for the transplantability of HPCs after thawing.

Blood Banks↗

PubMed2003

The absolute number of peripheral blood CD34+ cells predicts a timing for apheresis and progenitor cell yield in patients with hematologic malignancies and solid tumors.

Retrospective analysis was conducted in 51 autologous peripheral blood progenitor cell (PBPC) collections using the Spectra AutoPBSC System from patients with hematologic malignancies and solid tumors to study the predictive value of CD34+ cell counts in the peripheral blood for the yield of CD34+ cells in the apheresis product. The correlation coefficients for CD34+ cells microL(-1) of peripheral blood with CD34+ cell yield (x 10(6) kg(-1) of body weight and x 10(5) kg(-1) of body weight L(-1) of blood processed) were 0.903 and 0.778 (n=51 collections), respectively. Products collected from patients with CD34+ cell counts below 15 microL(-1) in the peripheral blood contained a median of 0.49 x 10(6) CD34+ cells kg(-1) (range: 0.05-2.55), whereas those with CD34+ cell counts more than 15 microL(-1) contained a median of 3.72 x 10(6) CD34+ cells kg(-1) (range: 1.06-37.57). From these results, a number of at least 15 CD34+ cells microL(-1) in the peripheral blood ensured a minimum yield of 1 x 10(6) CD34+ cells kg(-1) as obtained by a single apheresis procedure. The number of CD34+ cells in the peripheral blood can be used as a good predictor for timing of apheresis and estimating PBPC yield. With regard to our results, apheresis with a possibly poor efficiency should be avoided because the collection procedure is time-consuming and expensive.

Adolescent↗

PubMed2002

Diagnosis of Epstein-Barr virus-associated diseases.

Epstein-Barr virus (EBV) is a common DNA virus distributed worldwide. Usually the initial infection involves the upper respiratory tract without any problems and almost the entire population more than 25 years old test positive for anti-EBV antibodies. However, EBV often causes not only acute lytic infection but also chronic active infection with B cells and even T cells. In addition the EBV genome has been detected in tumors of hematopoietic or epithelial cell origin such as Burkitt's lymphomas, Hodgkin's disease, NK/T cell lymphomas, nasopharyngeal carcinomas (NPCs) and gastric adenocarcinomas. It is clearly important to make a correct diagnosis for EBV associated diseases and monitor the EBV load in individual patients for an appropriate therapy. In this paper recent advances in serological, immunological and molecular approaches for detection of EBV associated disease are described.

Adult↗

PubMed2002

Treatment responses of childhood aplastic anaemia with chromosomal aberrations at diagnosis.

The clinical outcome of childhood aplastic anaemia (AA) with aberrant cytogenetic clones at diagnosis was surveyed. Among 198 children with newly diagnosed AA registered with the AA Committee of the Japanese Society of Paediatric Hematology between 1994 and 1998, cytogenetic studies of bone marrow (BM) cells were completed in 159 patients. Apart from one Robertsonian translocation, seven patients (4.4%) showed clonal chromosomal abnormalities in hypoplastic BM without myelodysplastic features. The patients included six girls and one boy with a median age of 11 years (range 5-14 years). Six patients had del(6), del(5), del(13), del(20), or -7, and one showed add(9). Four patients responded to the first immunosuppressive therapy (IST: cyclosporin A plus anti-thymocyte globulin) and one obtained a spontaneous remission. Cytogenetic abnormalities remained in two patients with an IST response. On the other hand, two patients showed no IST response. One did not respond to repeat IST and died of acute graft-versus-host disease after an unrelated-BM transplant. Another obtained a complete response after a successful BM transplant. No haematological findings at diagnosis predicted the treatment response. No significant morphological changes developed during the course of the illness. A literature review revealed that half of 24 AA patients with chromosomal abnormalities responded to the first IST, and that +6 was the sole predictable marker for IST unresponsiveness. These results suggest that IST can be applied as the initial therapy for AA with cytogenetic abnormalities in the absence of completely matched donors.

Adolescent↗