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Biomedical subjects

J Tamura

Publications and source records attributed to J Tamura.

At least 55 records · Page 3Linked to original sources
PubMed1999

Involvement of the core protein in the first beta-N-acetylgalactosamine transfer to the glycosaminoglycan-protein linkage-region tetrasaccharide and in the subsequent polymerization: the critical determining step for chondroitin sulphate biosynthesis.

alpha-Thrombomodulin (alpha-TM) with a truncated glycosaminoglycan-protein linkage tetrasaccharide, GlcAbeta1-3Galbeta1-3Galbeta1-4Xyl, was tested as an acceptor together with a sugar donor, UDP-N-[3H]acetylgalactosamine, using a cell-free enzyme system prepared from the serum-free culture medium of a human melanoma cell line. The truncated tetrasaccharide on alpha-TM served as an acceptor, whereas the linkage tetrasaccharide-serine did not. Our characterization of the radioactively labelled product by enzymic digestion revealed that the N-[3H]acetylgalactosamine residue was transferred to alpha-TM through a beta1,4-linkage. The substrate competition experiments with the chondro-hexasaccharide and alpha-TM reinforced our speculation that a common N-acetylgalactosaminyltransferase catalysed the transfer of N-acetylgalactosamine to both the linkage tetrasaccharide and the longer chondroitin oligosaccharides. Moreover, chondroitin polymerization was demonstrated on the tetrasaccharide of alpha-TM using both UDP-glucuronic acid and UDP-N-acetylgalactosamine as sugar donors. Much longer chains were synthesized on alpha-TM than on the linkage penta- and hexa-saccharide-serines. Together, these results indicated that the core protein is required for the transfer of the first N-acetylgalactosamine residue through a beta1,4-linkage and also for subsequent efficient chain polymerization reactions, and that the critical determining step for chondroitin sulphate biosynthesis is the transfer of the first N-acetylgalactosamine residue.

Acetylgalactosamine↗
PubMed1999

Myelodysplastic syndromes with nephrotic syndrome.

It is sometimes reported that the immunological abnormalities in myelodysplastic syndromes (MDS) induce autoimmune disease (i.e., acute systemic vasculitic syndrome, chronic cutaneous vasculitis, polyneuropathy, relapsing polychondritis, and steroid-responsive pulmonary disorders). We investigated the clinical features of patients with MDS accompanied by nephrotic syndrome. We enrolled 125 patients with MDS who were admitted between January 1979 and May 1996 in this study. The renal function was assessed based on the laboratory data and the findings at the physical examination. The diagnoses of nephrotic syndrome and glomerular disease were established when 24-hr urinary excretion was more than 3.5 g and serum total protein was less than 6.0 g/dl, and when the 24-hr protein excretion was more than 1.5 g. Five patients (4%) had glomerular disease, and three (2.4%) had nephrotic syndrome. Of the five patients with glomerular disease, two had refractory anemia (RA), and three had chronic myelomonocytic leukemia (CMMOL). Three of the total 11 patients with CMMOL were diagnosed as having nephrotic syndrome. Among the CMMOL patients, those with nephrotic syndrome showed higher absolute monocyte numbers than did those without nephrotic syndrome (8830 +/- 4677/microl vs. 3061 +/- 2887/microl, P = 0.03). One CMMOL patient was treated with VP-16 and hydroxyurea. As the white blood cell count in this patient decreased, the 24-hr urine protein excretion and the serum tumor necrosis factor alpha level decreased. The relationship between nephrotic syndrome and CMMOL was not clear. High monocyte count and the serum cytokines in MDS patients may play a partial role in the evolution of glomerulonephritis, and CMMOL may be closely related to nephrotic syndrome.

Aged↗
PubMed1999

Osteoconductivity and bone-bonding strength of high- and low-viscous bioactive bone cements.

A study was conducted to evaluate the osteoconductivity and bone-bonding ability of two types of bioactive bone cement, both consisting of apatite and wollastonite containing glass-ceramic powder (AW-P), fused silica glass powder (SG-P), submicron fumed silica as an inorganic filler, and bisphenol-a-glycidyl methacrylate (Bis-GMA) based resin as an organic matrix. The cements had two kinds of formulas: one (dough-type cement; designated DTC) composed of 85% (w/w) filler and 15% resin, which was developed for fixation of the acetabular component in total hip arthroplasty and could be handled manually; and one (injection-type cement; designated ITC) composed of 79% (w/w) filler and 21% resin. ITC was developed for fixation of the femoral component and, because it had a lower viscosity than DTC, could be injected. The DTC and ITC both contained 73% AW-P, 25% SG-P, and 2% fumed silica in the weight ratio of the filler component. Two other types of cement, both of which consisted of 83.3% AW-P or SG-P, 1.7% fumed silica, and 15% resin, were used as reference material (designated AWC or SGC) for a detaching test. Following the packing of bone defects in the rat tibiae with either DTC or ITC, histological examination revealed that the DTC and ITC had both directly contacted the bone and were almost completely surrounded by bone by 16 weeks after the surgery and that no marked biodegradation had occurred at 52 weeks postimplantation. Rectangular plates (2 x 10 x 15 mm) of AWC, DTC, ITC, and SGC were implanted into the metaphysis of the tibia of male rabbits and the failure load was measured by a detaching test at 10 and 25 weeks after implantation. The failure loads of AWC, DTC, ITC, and SGC were 3.65, 2.21, 2.44, and 0.04 kgf at 10 weeks and 4.87, 2. 81, 2.82, and 0.13 kgf at 25 weeks, respectively. Observation of the bone-implant interface by scanning electron microscopy and energy dispersive X-ray microanalysis revealed that all the samples except SGC formed direct contact with the bone and that only AWC-implanted tibiae had a layer of a low calcium and phosphorus level at the bone-implant interface. Results showed that DTC and ITC have excellent osteoconductivity and bone-bonding ability under non-weight-bearing conditions.

Animals↗
PubMed1999

Prognostic value of morphological classifications and clinical variables in elderly and young patients with multiple myeloma.

The prognostic value of morphological classifications and clinical variables was compared between 31 elderly (> or = 65 years) and 43 young (< 65 years) patients with myeloma. Prognostic factors were divided into three groups: factors useful in elderly patients, e.g., calcium, albumin; factors useful in young patients, e.g., platelet, creatinine, light-chain type; and factors useful in both patients, e.g., clinical stage, hemoglobin, LDH, CRP, bone marrow plasma cell and plasmablast percentages, light- and electron-microscopic classifications. The 5-year survival rates of elderly patients with calcium < 12 and > or = 12 mg/dl were 66.2 and < 11.1%, respectively (p<0.01). Those of the young patients were 64.1 and 33.3%, respectively. The 5-year survival rates of elderly patients with platelets > or = 200 x 10(9)/l and < 100 x 10(9)/l were 59.7 and 50.0%, respectively. Those of the young patients were 68.9 and 33.3%, respectively (p<0.05). The 5-year survival rates of elderly patients with few and numerous electron-microscopic abnormalities were 90 and 0%, respectively (p<0.01), those of young patients were 92.9 and < 14.3%, respectively (p<0.01). These findings suggest that individual clinical variables may differ in prognostic importance in elderly and young patients.

Age Factors↗
PubMed1999

Primary nonsecretory plasma cell leukemia: a rare variant of multiple myeloma.

We report a patient with primary nonsecretory plasma cell leukemia. These cells resembled prolymphocytes and expressed only CD38 and CD56. Due to the atypical morphology and lack of monoclonal immunoglobulins in both serum and urine, it was difficult to make a correct diagnosis. Electron-microscopic and immunocytochemical cytoplasmic studies were useful.

Aged↗
PubMed1999

Immunomodulation by vitamin B12: augmentation of CD8+ T lymphocytes and natural killer (NK) cell activity in vitamin B12-deficient patients by methyl-B12 treatment.

It has been suggested that vitamin B12 (vit.B12) plays an important role in immune system regulation, but the details are still obscure. In order to examine the action of vit.B12 on cells of the human immune system, lymphocyte subpopulations and NK cell activity were evaluated in 11 patients with vit.B12 deficiency anaemia and in 13 control subjects. Decreases in the number of lymphocytes and CD8+ cells and in the proportion of CD4+ cells, an abnormally high CD4/CD8 ratio, and suppressed NK cell activity were noted in patients compared with control subjects. In all 11 patients and eight control subjects, these immune parameters were evaluated before and after methyl-B12 injection. The lymphocyte counts and number of CD8+ cells increased both in patients and in control subjects. The high CD4/CD8 ratio and suppressed NK cell activity were improved by methyl-B12 treatment. Augmentation of CD3-CD16+ cells occurred in patients after methyl-B12 treatment. In contrast, antibody-dependent cell-mediated cytotoxicity (ADCC) activity, lectin-stimulated lymphocyte blast formation, and serum levels of immunoglobulins were not changed by methyl-B12 treatment. These results indicate that vit.B12 might play an important role in cellular immunity, especially relativing to CD8+ cells and the NK cell system, which suggests effects on cytotoxic cells. We conclude that vit.B12 acts as an immunomodulator for cellular immunity.

Adjuvants, Immunologic↗
PubMed1999

A staging system for multiple myeloma based on the morphology of myeloma cells.

The morphology of myeloma cells is reported to be one of the prognostic factors in multiple myeloma (MM) patients. We analyzed the prognostic factors, including morphological classification, in 292 patients with MM in order to select poor-risk patients who should be considered candidates for early intensive chemotherapy, including stem cell transplantation. Multivariate analysis was applied to 90 patients diagnosed between 1989 and 1996, because serum beta-2-microglobulin (beta2M) has been measured regularly since 1989, and showed that serum albumin, serum beta2M, and the morphology of myeloma cells predicted survival. According to these factors, patients were divided into 3 risk groups; a high-risk group (14%), a intermediate-risk group (46%) and a low-risk group (40%). There were significant differences between survival times in these 3 groups (median survival: high-risk, 16; intermediate-risk, 22; and low-risk, 44 months).

Aged↗
PubMed1999

[The role of protein kinases and phosphatases in erythroid colony formation of elderly].

Using H-7, HA1001, FK506, cyclosporin A (CsA) and okadaic acid (OA), which are protein kinase and phosphatase inhibitors, we examined qualitative changes in hematopoietic precursor cells due to aging from the viewpoint of the role of protein kinases and phosphatases. Though H-7 and OA suppressed erythroid colony formation both in the elderly (age: 72-92, median: 86) and the young (age: 22-39, median: 29), no change due to aging was noted. HA1001 did not affect erythroid colony formation either in the elderly or the young. Erythroid colony formation was enhanced by FK506 and CsA in the young, however, erythroid colony formation was suppressed in the elderly. Similar examinations using cell fractions of non-T, non-macrophage, non-T + T, and CD34 positive cells were performed in both groups. Enhancement of erythroid colony formation in the young and suppression in the elderly by FK506 using unseparated MNC disappeared after removal of T cells. Enhancement of colony formation in the young and suppression of colony formation in the elderly were recovered when T cells were added again. The effects of FK506 and CsA on erythroid colony formation were thought to be the results of T cell inactivation, and the different sensitivity to FK506 and CsA in the elderly and young seemed to be the result of changes in the control mechanisms of hematopoiesis, such as the regulation of cytokine production by T cells, caused by aging.

Adult↗
PubMed1999

[Myelodysplastic syndrome accompanied by i(17) (q10) anomaly following pure red cell aplasia and transient myeloproliferative stage].

A 71-year-old man was given a diagnosis of pure red cell aplasia (PRCA) in May 1995. However, immunosuppressive agents, including prednisolone, azathioprine, and cyclosporin A, were not effective, and he required frequent red cell transfusions. In September 1995, leukocytosis and thrombocytosis developed (peaking at 10,100/microliter white cells and 98.1 x 10(4)/microliter platelets, respectively, in November 1996). Conversely, the patient's peripheral blood count began to decrease in July 1996, and pancytopenia progressed thereafter i(17) (q10) chromosomal abnormality of bone marrow cells was detected in November 1996. The patient was readmitted due to the progression of thrombocytopenia (1.2 x 10(4)/microliter). His bone marrow has 16.6% blasts, and a diagnosis of myelodysplastic syndrome (MDS) was made. The patient died in November 1997. His hematological state demonstrated significant changes in a relatively short period and severe hypoerythropoiesis and eosinophilia of the bone marrow persisted throughout the clinical course. These findings suggested that a common deranged stem cell was the origin of 3 different states; PRCA, chromic myeloproliferative disorder, and MDS. The i(17) (q10) anomaly may have caused the acute proliferation of blasts and pancytopenia.

Aged↗
PubMed1999

No beneficial effect from addition of etoposide to daunorubicin, cytarabine, and 6-mercaptopurine in individualized induction therapy of adult acute myeloid leukemia: the JALSG-AML92 study. Japan Adult Leukemia Study Group.

To assess the efficacy of etoposide added to the standard remission induction therapy for acute myeloid leukemia (AML), newly diagnosed adult AML patients were randomized to receive either daunorubicin (40 mg/m2/day x 4 or more), behenoyl cytarabine (200 mg/m2/day x 10 or more), and 6-mercaptopurine (70 mg/m2/day x 10 or more) (BHAC-DM), or the same three drugs plus etoposide (100 mg/m2/day x 5) (BHAC-EDM) for response-oriented individualized induction therapy. The patients achieving complete remission (CR) received the same 3 courses of consolidation therapy followed by 6 courses of maintenance/intensification therapy. M3 patients were excluded because all-trans retinoic acid was used. Of 667 patients registered, 655 were evaluable. The median age was 49 (range 15 to 85). CR rates were 77% in the BHAC-DM group and 75% in the BHAC-EDM group. In 173 M4 patients, CR rates were 86% and 69% (P = 0.009), and in 32 M5 patients, 80% and 77% (P = 0.810) in the BHAC-DM and the BHAC-EDM groups, respectively. The predicted 6-year overall survival rates were 30% and 38% (P = 0.925) for the BHAC-DM and BHAC-EDM groups, and the disease-free survival rates of CR patients were 25% and 35% (P = 0.352), respectively. Nonhematological toxicities after the first course of induction therapy were almost equal among the two groups, with the exception of a greater loss of hair (P = 0.024) and more frequent diarrhea (P = 0.013) in the BHAC-EDM group. We concluded that in the present study, the addition of etoposide to the standard individualized induction therapy showed no advantage in adult AML, even among M4 and M5 patients.

Acute Disease↗
PubMed1999

Effects of physical therapy on cytokines and two color analysis-lymphocyte subsets in patients with cerebrovascular diseases.

The effects of physical therapy on immunological parameters were evaluated in 12 patients (8 males and 4 females, 69.2 +/- 9.0 years) with cerebrovascular diseases in a stable situation two to three months after the onset of stroke who entered in our hospital between 1994 and 1997. After a two-month physical therapy program, the proportions of helper-inducer T (Thi) cells and suppressor-inducer T (Tsi) cells were increased significantly and that of cytotoxic T (Tc) cells was decreased, although those of HLA-DR+, suppressor T (Ts) and activated T (Tac) cells were not changed. The antibody dependent cellular cytotoxicity (ADCC) was significantly increased, although natural killer (NK) cell activity was not changed. The serum levels of interleukin-2 receptor was significantly increased but those of interleukin-2, interleukin-6 and interleukin-12 were not changed. The serum levels of interleukin-10, interleukin-12 and tumor necrosis factor-alpha were not detectable, while interleukin-1beta was decreased in 2 patients and interleukin-10 was increased in 2 patients. These findings suggest that daily physical exercise may activate the immune system possibly through the cytokine network in patients with cerebrovascular diseases (CVD).

Aged↗
PubMed1999

Clinical analysis of breathing exercise during immersion in 38 degrees C water for obstructive and constrictive pulmonary diseases.

Breathing exercises during immersion in 38 degrees C water were performed in 22 patients with bronchial asthma, pulmonary emphysema and constrictive pulmonary diseases. The patients entered a pool filled with 38 degrees C water to shoulder level. While standing, they breathed in deeply and breathed out slowly through the mouth into water while sinking the nose below the water level. This breathing method was repeated for 20 min. with a 5-min. rest out of water and this cycle was performed twice a day for two months. Respiratory function test and arterial blood gas analysis were examined before and after the two-month exercise program. FEV1.0% was significantly increased in patients with asthma and emphysema (p = 0.042 and 0.032, respectively) but did not change in patients with constrictive pulmonary diseases. %FVC, PF and Vmf25 did not change in any of the diseases. PaO2 was significantly increased in emphysematous patients (p = 0.0002) and PaCO2 was significantly decreased in asthmatic and emphysematous patients (p = 0.034 and 0.046, respectively). These results suggest that our breathing exercise by immersion is useful in patients with asthma and emphysema but is less effective in patients with constrictive pulmonary diseases.

Aged↗
PubMed1999

Successful low-dose cytosine arabinoside treatment in a patient with acute leukemia from idiopathic myelofibrosis.

We report a 63-year-old male with acute leukemia developed from idiopathic myelofibrosis. Cytogenetic analysis revealed chromosomal abnormalities; 46,XY,t(3;21)(q21;q22) del(20q). Intensive chemotherapies [combination of adriamycine/vincristine/prednisolone, or idarubicine/cytosine arabinoside (Ara-C)] were unsuccessful. The patient was then treated with continuous intravenous low-dose Ara-C because of his poor physical condition and showed marked hematological improvement. Leukemic cells disappeared from the peripheral blood and the segmented neutrophil count recovered. The dysplastic morphology observed in the segmented neutrophils suggests that the recovery of the neutrophils has resulted mainly from the differentiation activity of Ara-C.

Acute Disease↗
PubMed1999

[Autoimmune neutropenia accompanied by Tolosa-Hunt syndrome].

A 47-year-old woman presented with severe neutropenia accompanied by diplopia and orbital pain. Her bone marrow was normal except for the absence of segmented neutrophils. Because the administration of granulocyte colony-stimulating factor (G-CSF) at a dose of 1 microgram/kg/day was not sufficiently effective and neutropenia developed, the patient was admitted to our hospital. Physical examination revealed painful ophthalmoplegia and hypoalgesia in the first region of trigeminal nerve, suggestive of Tolosa-Hunt syndrome. Severe neutropenia was observed in both peripheral blood and bone marrow, together with mild anemia and thrombocytopenia. The life span of red cells and platelets was shortened. High PAIgG levels, a positive Coombs test, and a positive test for anti-NA1 antibody suggested that blood cells were being destroyed by an autoimmune mechanism. Corticosteroid hormone therapy preceded by the administration of G-CSF at 5 micrograms/kg/day was effective for both neutropenia and in improving the patient's neurological findings.

Autoimmune Diseases↗
PubMed1998

Molecular cloning and expression of glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans.

We isolated a cDNA encoding a novel glucuronyltransferase from human placenta cDNA with the use of the degenerate reverse transcriptase-polymerase chain reaction method. Degenerate primers were designed based upon the amino acid sequence alignment of rat glucuronyltransferase (GlcAT-P) involved in the biosynthesis of the carbohydrate epitope HNK-1 with putative proteins in Caenorhabditis elegans and Schistosoma mansoni. The new cDNA sequence revealed an open reading frame coding for a protein of 335 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 43% identity to the rat GlcAT-P, and the highest sequence identity was found in the COOH-terminal catalytic domain. The expression of a soluble recombinant form of the protein in COS-1 cells produced an active glucuronyltransferase with marked specificity for a glycoserine Galbeta1-3Galbeta1-4Xylbeta1-O-Ser. In contrast, asialoorosomucoid, which contains the Galbeta1-4GlcNAc sequence and is a good acceptor substrate for the GlcAT-P, did not serve as an acceptor. The reaction product was sensitive to beta-glucuronidase digestion and co-chromatographed with authentic GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser in high-performance liquid chromatography, suggesting that the enzyme is a beta1, 3-glucuronyltransferase. These results indicate that this new member of the glucuronyltransferase gene family is the enzyme previously described as glucuronyltransferase I that forms the glycosaminoglycan-protein linkage region, GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser, of proteoglycans.

Amino Acid Sequence↗
PubMed1998

Coincidental occurrence of pernicious anemia and mycosis fungoides in two elderly males.

We experienced two rare cases of pernicious anemia that presented in the course of mycosis fungoides in elderly males. Pernicious anemia has recently been reported to be caused by autoimmune gastritis that produces autoantibodies to gastric parietal cells and intrinsic factor. Immunological abnormalities in mycosis fungoides are reported to induce autoimmune diseases (i.e., autoimmune hemolytic anemia, anti-phospholipid antibody syndrome, arthritis, myasthenia gravis, necrotizing vasculitis, and vitiligo); the pernicious anemia in our two patients may have been closely related to the mycosis fungoides.

Aged↗