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Biomedical subjects

S Kai

Publications and source records attributed to S Kai.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Fundamental and clinical study of three-dimensional compensating filters and direct dose monitoring system for total body irradiation].

We devised 3D-compensating filters to improve dose distribution during total body irradiation (TBI). This study investigated the effect of these 3D-compensating filters and related complications in patients who had undergone bone marrow transplantation (BMT) followed by TBI. The 3D-compensating filters were fabricated by CT measurement of body thickness. The effectiveness of the 3D-compensating filters in producing a homogeneous dose distribution was checked by a thermoluminescent dosimeter (TLD) and semiconductor detectors in all patients. At the pelvis, the dose was measured simultaneously with an ionization chamber. The average dose distribution to each site when the 3D-compensating filter was used was 93% to the head, 97% to the neck, 99% to the thorax, and 98% to the pelvis in TLD when the scheduled dose was taken as 100%. There was no significant difference between the TBI and non-TBI groups with regard to the frequency of lung toxicity. Clinical interstitial pneumonitis occurred in 22.7% of the patients, interstitial pneumonitis with CMV in 13.6%, and idiopathic pneumonitis in 6.1% without any virus infection. Only one patient was regarded as having radiation-induced pneumonitis. 3D-compensating filters can be conveniently produced within a short time following CT measurement, and they seem to be safe and useful for dose flattening during TBI.

Adolescent↗
PubMed1998

Evidence that CD31, CD49b, and CD62L are immunodominant minor histocompatibility antigens in HLA identical sibling bone marrow transplants.

Despite complete matching of siblings for the HLA loci, after bone marrow transplantation (BMT), approximately 20% develop graft-versus-host disease (GVHD). This is presumably due to incompatibility of minor histocompatibility antigens (mHa). We investigated the polymorphisms of 14 adhesion molecules (CD2, CD28, CD31, CD34, CD36, CD42, CD44, CD48, CD49b, CD54, CD62L, CD86, CD102, and CD106) in Japanese subjects and their association with the occurrence of GVHD after allogeneic HLA identical BMT. Six molecules (CD2, CD31, CD42, CD49b, CD54, and CD62L), which were found to be polymorphic, were then examined in 118 HLA identical sibling donors and recipients who had undergone BMT. Association of the incompatibility of the polymorphic molecules with the presence or absence of GVHD was examined. In these six, we observed a significant correlation between acute GVHD and the compatibility of CD31 (codons 563/670) (Pcorrected = .018), and CD31 (codons 563/670) + CD62L (Pcorrected = .018) in patients with the HLA-B44-like superfamily. In patients with the HLA-A3-like superfamily, the compatibility of CD62L (Pcorrected = .03) and CD62L + CD49b (P = . 004, Pcorrected = .078) was associated with acute GVHD. Therefore, CD31, CD49b, and CD62L might be candidates for immunodominant mHa.

Adolescent↗
PubMed1998

Protective effects of green tea on hepatotoxicity, oxidative DNA damage and cell proliferation in the rat liver induced by repeated oral administration of 2-nitropropane.

To evaluate the benefit of green tea in mitigating hazards caused by repeated exposure of 2-nitropropane (2NP), we examined the effects of the tea on toxic indices, oxidative DNA damage and cell proliferation in the liver of 2NP-treated rats. Male Fischer 344 rats were administered, by gastric intubation, a total of six doses of 60 mg/kg 2NP(L), or alternatively two doses of 90 mg/kg and then four doses of 120 mg/kg 2NP(H) during 2 weeks. Green tea infusion was given to the rats as drinking water 1 week before the 2NP treatments and throughout the experiment. Significant elevation of hepatotoxic indices was evident in the 2NP(H)-treated group, such as an increase of serum glutamic-oxaloacetic transaminase (GOT) activity and of hepatic lipid peroxidation, together with a decrease in hepatic glycogen and serum triglyceride, and degenerative changes in the hepatocytes. A dose-related increase was observed in oxidative DNA damage and cell proliferation in the liver. Green tea effectively inhibited all of above changes induced by 2NP treatment, suggesting that tea intake may be effective for preventing the hepatic injuries after chronic exposure to 2NP.

Animals↗
PubMed1998

Loss of heterozygosity of NF1 gene in juvenile chronic myelogenous leukemia with neurofibromatosis type 1.

To investigate a genetic relation between juvenile chronic myelogenous leukemia (JCML) and neurofibromatosis type 1 (NF-1), we analyzed the NF1 gene in the leukemic cells of a JCML patient with NF-1. We found a point mutation in exon 29 of one allele and a deletion of the other normal allele in the leukemic cells. The point mutation is considered a germline mutation because it was also detected in fibroblasts obtained from the bone marrow of the patient and the peripheral blood mononuclear cells from a sibling. A loss of heterozygosity of NF1 gene may contribute to the progression of leukemia in NF-1 patients.

Alleles↗
PubMed1998

Long-term outcomes of nonsurgical treatment in nonreducing anteriorly displaced disk of the temporomandibular joint.

OBJECTIVES: The aim of this study was to evaluate long-term outcomes of nonsurgical treatment in patients with persistent anterior disk displacement without reduction of the temporomandibular joint. STUDY DESIGN: Thirty-five patients were treated with occlusal splints, and 12 patients underwent additional occlusal treatments after splint treatment. These patients were evaluated clinically and radiographically. At least 2 years after the treatment, the 34 patients' symptoms were assessed with the use of a questionnaire. RESULTS: The mean maximal interincisal distance (MID) was 27.6 mm before treatment and 44.4 mm at the end of treatment (p < 0.001). Before the treatment, all 35 patients had complained of pain, and mild pain persisted in 9 patients at the end of treatment. Flattening of the condylar head and of the articular eminence increased in prevalence from 12.1% and 9.1%, respectively, before treatment to 54.5% and 51.5%, respectively, at the time of follow-up observation. At the time of the survey, the mean self-reported MID was 46.8 mm (p < 0.01). CONCLUSIONS: After the nonsurgical treatment, the clinical signs and symptoms improved significantly, although the prevalence of osteoarthrotic findings increased.

Adolescent↗
PubMed1997

[Readmission among discharged psychiatric patients and it's correlates].

OBJECTIVE: This study investigated the incidence of readmission among discharged psychiatric patients and examined factors predicting early readmission. METHODS: A cohort of 343 patients, who had been hospitalized involuntarily to mental hospitals for medical care and custody, and who were discharged between April 1991 and September 1993, in two areas served by Fukuoka Prefectural Yamato Health Center (n = 163) and Tagawa Health Center (n = 180) were followed up until November 1994. RESULTS: The readmission rates within 6 months of discharge in Yamato Health Center and Tagawa Health Center were 17% and 22%, and within 1 year were 30% and 31% respectively. From Cox's proportional hazards model, alcohol/drug abuse, many of previous admission, long length of recent hospitalization, payment of medical care cost from public assistance, complication of physical disorders, living without a person responsible for custody after discharge, no request of health center's service by the hospital and discharge from a large-scale mental hospital were significantly related to increased risk of readmission. Not a few patients could not be followed up completely because of early drop-out of treatment. The drop-out rates within 1 month of discharge in Yamato Health Center and Tagawa Health Center were 10% and 26%, and within 1 year were 15% and 27% respectively. CONCLUSIONS: The rates of readmission and drop-out of treatment among discharged psychiatric patients were considerably high. This study clarified that rapid establishment of a mental health system supporting the mentally disabled in a community is an urgent need in Japan.

Adult↗
PubMed1996

In vitro differentiation of murine Sca-1+Lin- cells into myeloid, B cell and T cell lineages.

Hematopoietic progenitor cells were shown to be capable of differentiating into myeloid, B cell and T cell lineages. We used a two-step culture system in which enriched murine hematopoietic progenitors in bone marrow were first plated in viscid culture medium containing methylcellulose, erythropoietin (EPO), stem cell factor (SCF) and interleukin (IL)-7. One thousand enriched murine marrow cells formed 53.5 +/- 12.1 (mean +/- SD) primary colonies. Cells from a single blast colony were separated into two aliquots and replated in secondary methylcellulose cultures containing SCF and IL-7 for B cell lineage and SCF, IL-3, G-CSF, GM-CSF and EPO for myeloid lineage. Next, cells from five to ten primary blast colonies were cultured again in embryonal thymus (25 Gy irradiated). One aliquot of blast colonies in a primary culture contained four colony forming units (CFU) of granulocytes, erythroblasts, macrophages and megakaryocytes, eight CFU-granulocytes and macrophages, and 28 BFU-E in a representative secondary myeloid culture. Another aliquot formed a few B cell colonies (2-10) in a secondary B cell culture. B lymphoid colonies were composed of blast-like cells with B-220 antigen. T cells in a secondary T cell culture consisted of 16% L3T4+, 16% CD8+ and 11% CD3+ of bone marrow origin in the thymus. From these results, we concluded that cells in the primary colonies from Sca-1+Lin- hematopoietic stem cells could differentiate into B cell, T cell and myeloid lineages.

Animals↗
PubMed1996

Autoradiographic evidence of steroid affinity sites in nasal tissue.

Affinity sites of glucocorticoid (GC) in nasal tissue were investigated using radiolabelled synthetic GC. The affinity sites of GC are epithelium, vein, leukocyte and gland. The tracer was retained in the cytoplasma but not in the nuclei in most parts of the nasal tissue except for the endothelial cells of the vein. Therefore we assume that there is a direct mechanism of steroid action on nasal tissue suffering from allergic rhinitics other than the so-called steroid-receptor complex. Affinity sites of corticosterone (CS) in nasal tissue were investigated using radiolabelled CS. The differences of affinity sites of GC and mineralcorticoid in unsensitized rats were evaluated, but no major differences between them could be confirmed.

Affinity Labels↗
PubMed1996

[Clinical statistics on operations during a ten-year period (1985-1994) at department of urology, Handa Hospital].

A clinical statistic survey was carried out on the operations performed at the Department of Urology, Handa Hospital between 1985 and 1994. The total number of operations was 2,532 and the number of operations other than extracorporeal shock-wave lithotripsy (ESWL) was 1,938. The mode of operation for urolithiasis has changed dramatically from open surgery to the ESWL and endourology.

Female↗
PubMed1995

Effects of erythropoietin, IL-3, IL-6 and LIF on a murine megakaryoblastic cell line: growth enhancement and expression of receptor mRNAs.

We examined the effects of recombinant human erythropoietin (rhEPO), recombinant murine interleukin 3 (rmIL-3), recombinant human interleukin 6 (rhIL-6), recombinant human interleukin 11 (rhIL-11), recombinant murine leukemia inhibitory factor (rmLIF) and recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) on the growth of murine megakaryocytic cell lines. In serum-free methylcellulose culture supplemented with bovine serum albumin (BSA), the addition of rhEPO (0.1-10 U/ml), rmIL-3 (10-500 U/ml), rhIL-6 (100-10,000 U/ml), rmLIF (100-10,000 U/ml), or rmGM-CSF (10-1000 U/ml) enhanced colony growth in L8057Y5 cells, which had been maintained in protein-free culture, mostly in a dose-dependent fashion; rhIL-11 did not have any stimulatory effect at the tested doses (10-1000 U/ml). In addition, colony growth of L8057 cells, which had been maintained in serum-containing culture, was enhanced, but to a lesser extent, by the addition of these cytokines except rhEPO (the cultures were supplemented with 1% fetal bovine serum. Among the cytokines that showed growth-enhancing effects on L8057 cells, the expression of mRNAs encoding receptors for EPO, IL-6 and IL-3 was examined by northern blot analysis or reverse transcription polymerase chain reaction (RT-PCR). In both cell lines, mRNAs for EPO-R, IL-6R, gp130, IL-3R alpha and beta chains were constitutively expressed. The results suggest that L8057 and L8057Y5 cell lines have characteristics of megakaryoblastic cells in their biological responses to cytokines, as well as in the expression of cytokine receptor mRNAs, and that the growth-enhancing effects of these cytokines on the cell lines may be achieved through specific receptors. Our findings show the value of these cell lines for investigating the mechanisms of growth signal transduction in megakaryopoiesis.

Animals↗
PubMed1995

Anti-A and/or anti-B is not detectable in some patients who underwent ABO-incompatible bone marrow transplantation.

BACKGROUND: Recently, anti-A and/or anti-B produced by B cells from donor marrow could not be detected for more than 20 weeks in some patients who had undergone ABO-incompatible bone marrow transplantation (BMT). STUDY DESIGN AND METHODS: Twelve to 72 weeks after 11 patients underwent ABO-incompatible BMT, titers of anti-A and anti-B were assayed, A and B antigens were identified by routine methods and flow cytometry, direct and indirect antiglobulin tests were performed, and the red cell antibody was eluted. RESULTS: In some patients who underwent ABO-incompatible BMT, anti-A and/or anti-B produced by the B cells from the donor marrow could not be detected after BMT when red cells taken from the patients before BMT carried the corresponding antigen--that is, when hematopoiesis had already changed the cells to the donor's type according to ABO blood typing. Furthermore, some blood samples from those patients gave positive results in direct antiglobulin tests. Blood typing of patients after BMT showed mixed-field agglutination. In one patient, the half-life of red cells assayed with 51Cr was 22.4 days (30.0 +/- 4.0 days for normal controls). CONCLUSION: Although many hypotheses could be considered to explain the present data, the possibility is proposed that anti-A and/or anti-B in the sera must have been consumed in some patients who underwent ABO-incompatible BMT. This may lead to problems such as difficulty of ABO typing, positive direct antiglobulin tests, and a relatively short life span of red cells.

ABO Blood-Group System↗
PubMed1995

Clonal analysis of peripheral blood and haemopoietic colonies in patients with aplastic anaemia and refractory anaemia using the polymorphic short tandem repeat on the human androgen-receptor (HUMARA) gene.

The clonalities in white blood cells (WBC) of blood and nucleated bone marrow cells from patients with refractory anaemia and aplastic anaemia were examined by polymerase chain reaction (PCR) methods using the polymorphic short tandem repeat (STR) on the human androgen-receptor gene (HUMARA). Peripheral blood samples were obtained from 12 female patients, six with aplastic anaemia (AA) and six with refractory anaemia (RA). Peripheral blood was fractionated into granulocytes, lymphocytes, T lymphocytes and B lymphocytes. DNA was extracted from each fraction. Bone marrow samples were obtained from seven female patients (three with AA and four with RA). Sorted CD34 positive cells were cultured in a semisolid culture system. DNA was extracted from a 14-day haemopoietic colony. The clonal pattern was assessed using HUMARA gene STR polymorphism and the differential methylation pattern of nearby cytosine residues by PCR methods. Four of six (67%) AA and two of six (33%) RA patients had a monoclonal proliferating pattern in their granulocytes. The ratio of the numbers of minority colonies per majority colonies (m/M ratio) was examined for seven patients (three AA and four RA). In patients who had a clonal haemopoietic pattern in peripheral WBC the ratio was under 0.4 but not zero. In contrast, patients exhibiting a polyclonal pattern had an m/M ratio above 0.8. We concluded that some normal or heterogenous haemopoietic clones, not only MDS but also AA, may remain in the bone marrow, although almost all colonies were derived from a single pathogenic clone when the clonality pattern exhibited monoclonality in peripheral blood analysis.

Adult↗
PubMed1995

Involvement of the central nervous system in rheumatoid arthritis: its clinical manifestations and analysis by magnetic resonance imaging.

A rheumatoid arthritis (RA) patient showed high signal intensity in the subcortical region of the frontal and occipital lobes on T2-weighted magnetic resonance imaging (MRI). Histopathological examination in the autopsy specimen revealed severe systemic vasculitis. Additional radiological and laboratory studies revealed that transient cerebral ischemia induced by vasculitis occurred in this patient.

Arthritis, Rheumatoid↗