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Biomedical subjects

H Take

Publications and source records attributed to H Take.

At least 73 records · Page 4Linked to original sources

[Effect of G-CSF and M-CSF on busulfan-induced marrow failure in a 91-year old patient with essential thrombocythemia].

A 91-year-old patient with essential thrombocythemia presented with marked bone marrow suppression induced by long-term administration of busulfan. Her pancytopenia extended for over two months even after the cessation of busulfan, suggesting that she had developed a severe decrease in hematopoietic reserve. We administered G-CSF and M-CSF to accelerate recovery from marrow failure and to evaluate the recovery of hematopoiesis. The standard doses of G-CSF and M-CSF increased her neutrophil and platelet counts sufficiently but only transiently. Transient eosinophilia was also noted after cessation of M-CSF. The possibility that the expansion of abnormal clone(s) induced the transient increase in platelet and eosinophil counts could not be completely excluded. We suggest that the administration of hematopoietic growth factors should be limited to patients, irrespective of age, who present marked clinical symptoms attributable to marrow failure when the patient has a chronic myeloproliferative disorder.

Aged↗

Presence of the entire coding region of GP IV mRNA in Nak(a)-negative platelets.

It has been reported that Nak(a)-negative platelets lack GP IV. To examine the GP IV genetic defects in Nak(a)-negative platelets, we studied four unrelated Nak(a)-negative subjects by amplifying their GP IV cDNA, which were synthesized from platelet mRNA using the reverse transcriptase/polymerase chain reaction (RT/PCR). We detected the entire coding region of GP IV mRNA in the platelets of all four subjects. Restriction enzyme analysis of the amplified GP IV cDNA showed fully predictable cutting sites. These results suggest that no gross deletion or insertion had occurred in the GP IV mRNA of Nak(a)-negative platelets.

Antigens, CD↗

[Giant plasmacytoma of the skull which appeared in the clinical course of multiple myeloma--a case report].

A 51-year-old woman with large plasmacytoma occurring from the temporal bone is presented. She has a history of multiple myeloma for 9 years. She manifested marked swelling in the left temporal area with tenderness. Neurological examination revealed no abnormality. She showed monoclonal free light chain (lambda type) in the serum and urine, and had multiple osteolytic lesions in her general bones. T1 WI of MRI exhibited a huge mass showing slightly high intensity in the left middle fossa and infratemporal fossa, and a part of the mass protruded into the extracranial space. The mass was markedly enhanced by Gd-DTPA. Angiography showed a hypervascular mass supplied by the external carotid artery. Biopsy disclosed plasmacytoma. She underwent local irradiation of 30 Gy and chemotherapy of Ranimustine (100 mg) and Cyclophosphamide (400 mg). The tumor reduced its size, and tenderness in her temporal area disappeared.

Cerebral Angiography↗

[Pathogenic relevance of platelet-associated autoantibodies in chronic ITP--studies before and after splenectomy in three patients with chronic ITP by direct immunoprecipitation procedure].

This study was designed to investigate the pathogenic relevance of platelet-associated autoantibodies in chronic ITP, since the titer of platelet-associated autoantibodies does not appear to correlate with the severity of the disease. Employing a direct immunoprecipitation procedure, we examined platelets from three ITP patients with platelet-associated autoantibodies against GPIIb-IIIa and an unidentified 56 kD protein before and after splenectomy. In two patients, platelet-associated autoantibodies disappeared after splenectomy, and these two patients attained complete remission. In one patient, however, the amount of platelet-associated autoantibodies did not decrease after splenectomy. Although this patient's platelet count transiently increased to 500 x 10(3)/microliters after splenectomy, it decreased to 55 x 10(3)/microliters within a short time. These findings suggest that platelet-associated autoantibodies play a key role in platelet destruction in chronic ITP.

Adult↗

Effects of splenectomy on immune thrombocytopenic purpura in (NZW x BXSB) F1 mice: analyses of platelet kinetics and anti-platelet antibody production.

Effects of splenectomy on platelet kinetics and production of anti-platelet antibodies were studied in male (NZW x BXSB) F1 (W/B F1) mice, which are known as the animal model of immune thrombocytopenic purpura (ITP). Studies on organ localization of radiolabeled platelets revealed that splenic uptake significantly increases in W/B F1 mice in comparison with that of normal controls. W/B F1 mice showed a significant increase in platelet counts and, in contrast with sham-operated controls, high levels of platelet counts were maintained up to 6 weeks after splenectomy. Platelet lifespans (PLSs) did not reach normal levels, although prolonged PLSs were observed. In addition, platelet-associated antibody (PAA) values showed a tendency towards transient decrease, but there was no change in platelet-bindable serum antibodies (PBAs). These findings indicate that the suppression of anti-platelet antibody production is essential to the treatment of ITP; splenectomy may not be effective in treating severely affected ITP patients because, although the spleen is one of the major sites of platelet sequestration and antibody production, reticulo-endothelial systems (RESs) (liver, bone marrow, lymphnodes, etc.) other than the spleen are also responsible for the destruction of platelets. We therefore consider the W/B F1 mouse to be a useful model of human ITP, and believe that it provides valuable information for the development of new therapeutic agents in patients with ITP, especially those who do not respond to splenectomy.

Animals↗

Mechanisms of corticosteroid action in immune thrombocytopenic purpura (ITP): experimental studies using ITP-prone mice, (NZW x BXSB) F1.

To determine the mechanism by which platelet counts increase after corticosteroid therapy for human immune thrombocytopenic purpura (ITP), we studied the platelet kinetics using prednisolone (PDN)-treated ITP-prone mice, (NZW x BXSB) F1 (W/B F1). An increase in platelet counts was observed in W/B F1 mice (n = 10, mean +/- SD, 1,202 +/- 202 x 10(3)/microL) 4 weeks after treatment with PDN (2 mg/kg/d); no increase occurred in nontreated W/B F1 mice (n = 5,651 +/- 126, P less than .005). Prolonged platelet life-spans (PLSs) were observed in treated W/B F1 mice (1.29 +/- 0.40 days), but not in nontreated controls (0.60 +/- 0.24 days, P less than .01). No increase in platelet production (platelet turnover) was found in PDN-treated W/B F1 mice, but significant decreases in platelet-associated antibodies (PAAs) and platelet-bindable serum antibodies (PBAs) were noted. Studies on organ localization of radiolabeled platelets showed that hepatic uptake significantly decreased in the treated W/B F1 mice, but not in nontreated W/B F1 mice. To elucidate the effect of PDN on the reticulo-endothelial phagocytic activity in W/B F1 mice, we studied in vivo clearance of IgG-sensitized, 51Cr-labeled autologous erythrocytes. W/B F1 mice treated with PDN showed a marked impairment of their ability to clear these cells, although PDN had little effect on the number of splenic or hepatic macrophage Fc gamma receptors. These results and our previous findings of splenectomy suggest that PDN improves platelet counts not only by suppressing systemic reticulo-endothelial phagocytic function but also by reducing antibody production.

Animals↗

Impaired suppressor function of T cells induced by autologous mixed lymphocyte reaction in patients with idiopathic thrombocytopenic purpura.

Autologous mixed lymphocyte reaction (AMLR)-induced suppressor function was studied in 12 patients with chronic idiopathic thrombocytopenic purpura (ITP). The function was found to be significantly impaired (20 +/- 55%; p less than 0.005) compared with normal subjects (69 +/- 25%). AMLRs in these patients were significantly decreased (p less than 0.05) compared with normal subjects. There was no significant correlation between AMLR-induced suppressor function and platelet counts. Nine patients were studied for AMLR-induced suppressor function before and after splenectomy. The platelet counts increased significantly as a result of splenectomy, but the AMLR-induced suppressor function showed no significant improvement. The results of this study suggest that suppressor dysfunction in ITP may be an immunologic defect irrespective of disease activity. We consider that this abnormality may reflect in vivo failure of the immunoregulatory (feedback) mechanism in ITP.

Adult↗

[Clinical effects of cefodizime in severe infections complicated with hematological diseases. Hanshin Infection Study Group].

One hundred thirty-eight patients with severe infections accompanying hematological diseases were treated with cefodizime (CDZM). CDZM was administered by intravenous injection at daily doses ranging from 2 g to 8 g for about 3 to 18 days. Clinical efficacies of CDZM were excellent in 30 cases, good in 37 cases, fair in 1 case and poor in 53 cases. The efficacy rate was 55.4%. The efficacy rate was 56.4% in patients from whom causative organisms were not identified. The efficacy rate against Gram-negative bacteria (66.7%) was higher than that against Gram-positive bacteria (28.6%). No significant differences in the efficacy rates were found among groups of patients with different initial neutrophil counts (less than 100, 100-499, and over 500/microliters). Skin eruption caused by CDZM was observed in 2 patients (1.5%). Hepatic disorders, renal dysfunction and urinary test abnormality (protein and urobilinogen) were observed in 7 (5.0%), 1 (0.7%) and 1 (0.7%), respectively. Therefore, CDZM was considered to be a clinically useful antibiotic for severe infections complicated with hematological diseases.

Adolescent↗

[Therapeutic effects of meropenem against severe infections in patients with hematopoietic disorders. Hanshin Study Group of Hematopoietic Disorders and Infection].

The efficacy and the safety of meropenem (MEPM), a newly developed carbapenem antibiotic, were investigated in 150 patients with severe infections complicated with hematopoietic disorders. 1. Clinical responses in 132 patients who were evaluable for effectiveness were excellent in 33 patients, good in 45, fair in 10 and poor in 44, with an efficacy rate of 59.1%. 2. The efficacy rate in patients who had previously been treated with the other antibiotics was 51.2%, while that in patients who had not been thus treated was 62.9%. 3. The efficacy rate in patients whose neutrophil counts increased during the therapy with MEPM was higher than that in patients whose neutrophil counts did not increase. The efficacy rate in patients whose neutrophil counts during the therapy were below 100/mm3 was 48.1%. 4. Out of 150 cases, side effects were observed in 4 patients, 3 with eruption and 1 with jaundice. Abnormalities in laboratory test results on liver functions were noted in 8 patients. These results indicate that MEPM is an effective and safe antibiotic for the treatment of severe infections in patients with hematopoietic disorders.

Adolescent↗

B cells expressing CD5 antigen are markedly increased in peripheral blood and spleen lymphocytes from patients with immune thrombocytopenic purpura.

By two-colour flow cytometric analysis, we examined the proportion of B lymphocytes bearing CD5 cell surface antigen (CD 5+ B cells), which are capable of producing autoantibodies, both in peripheral blood and spleen from patients with chronic immune thrombocytopenic purpura (ITP). The percentage of CD5+ B cells in peripheral blood lymphocytes (PBLs) was significantly increased (P less than 0.005) in patients with ITP (3.7 +/- 2.2%, n = 30) as compared with normal controls (1.7 +/- 0.7%, n = 28). However, there was no correlation between the percentages of circulating CD5+ B cells and platelet counts. The percentage of splenic CD5+ B cells in ITP patients was much more increased (9.0 +/- 4.5%, n = 9), P less than 0.005) compared with that of other disorders (3.2 +/- 0.5%, n = 5). Furthermore, isolated splenic CD5+ B cells from two out of five ITP patients produced high levels of IgM-type, platelet-bindable antibodies (PBIgM) after stimulation with Staphylococcus aureus Cowan I (SAC), while CD5- B cells isolated from the same spleen or splenic CD5+ B cells from other non-autoimmune disorders failed to produce significant amount of PBIgM. In three ITP patients, no increase in PBIgM was detected despite SAC stimulation. The increased proportion of CD5+ B cells in peripheral blood and spleen, and their ability to produce anti-platelet antibodies indicate that they are directly involved in the autoimmune pathogenesis in ITP.

Adult↗

Analyses of thrombocytopenia in idiopathic thrombocytopenic purpura-prone mice by platelet transfer experiments between (NZW x BXSB)F1 and normal mice.

Male (NZW x BXSB) F1 (W/B F1) mice, which develop lupus nephritis, myocardial infarction, and thrombocytopenia, showed reduced platelet lifespan (PLS) and increased platelet-associated antibody (PAA) values. There were statistically significant correlations between the increase in PAA values and either the reduction in PLS or the decrease in platelet counts. This and the results of platelet transfer experiments between old male W/B F1 mice and either female W/B F1 or normal BALB/c mice indicate that PAAs on the platelet surface play a crucial role in the destruction of platelets in W/B F1 mice. The mechanism of thrombocytopenia observed here appears similar to that of human idiopathic thrombocytopenic purpura (ITP). Therefore, we think that W/B F1 mice are a potentially useful animal model for investigating the effectiveness and mode of action of therapeutic agents in human ITP, and that they may provide additional information on the basic mechanisms of this autoimmune phenomenon.

Animals↗

Identification of the platelet-specific alloantigen, Naka, on platelet membrane glycoprotein IV.

We describe the membrane localization of a new platelet-specific alloantigen, designated Naka, that is involved in refractoriness to HLA-matched platelet transfusions. By indirect immunoprecipitation, anti-Naka antibody precipitated a single, radiolabeled platelet membrane protein with a molecular weight (mol wt) of 91 Kd from Naka-positive platelets. When radiolabeled Naka-negative platelets were used as a source of target antigens, no radiolabeled proteins were precipitated. The analyses using nonreduced-reduced two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and using rabbit antiglycoprotein (GP)IV demonstrated that this protein corresponds to GPIV (alternatively GPIIIb). Furthermore, in dot immunobinding, anti-Naka antibody bound to purified GPIV. Our results provide definitive evidence that the Naka alloantigen is carried on GPIV. These results also demonstrate that, on occasion, antibodies against GPIV may play an important role in refractoriness to platelet transfusions.

Antigens, Surface↗

Identification of a compound heterozygote for adenine phosphoribosyltransferase deficiency (APRT*J/APART*Q0) leading to 2,8-dihydroxyadenine urolithiasis.

Homozygous deficiency of a purine salvage enzyme, adenine phosphoribosyltransferase (APRT), causes urolithiasis and renal failure. There are two known types of homozygous APRT deficiencies; type I patients completely lack APRT activity while type II patients only partially lack such activity. All type II patients possess at least one APRT*J allele with a substitution from ATG (Met) to ACG (Thr) at codon 136. Type I patients are considered to possess two alleles (APRT*Q0) both of which code for complete deficiencies. Thus, some patients with type II APRT deficiencies may have a genotype of APRT*J/APRT*Q0. As no individuals with such a genotype have previously been identified, we performed extensive analysis on four members of a family by (1) the T-cell method for the identification of a homozygote, (2) the B-cell method for the identification of heterozygotes, and (3) oligonucleotide hybridization after in vitro amplification of a part of genomic APRT sequence for the identification of APRT*J and non-APRT*J alleles. We report here the first evidence that 2,8-dihydroxyadenine urolithiasis developed in a boy aged 2 years with a genotype of APRT*J/APRT*Q0.

Adenine↗

Demonstration of platelet antigens that bind platelet-associated autoantibodies in chronic ITP by direct immunoprecipitation procedure.

Platelet antigens that bind platelet-associated autoantibodies in chronic idiopathic thrombocytopenic purpura (ITP) were demonstrated using a direct immunoprecipitation procedure. ITP platelets, with bound autoantibodies, were radiolabelled and solubilized, and then platelet antigen-antibody complexes adsorbed to protein A-bearing Staphylococcus aureus were analysed by 7.5% sodium dodecyl sulphate, polyacrylamide gel electrophoresis (SDS-PAGE). Direct immunoprecipitation demonstrated the presence of platelet-associated autoantibodies against glycoprotein (GP) IIb/IIIa in four of six ITP patients with an intensive band corresponding to platelet-associated IgG. These results were confirmed by indirect immunoprecipitation using ether eluates from two ITP patients. In addition, only direct immunoprecipitation demonstrated the presence of autoantibodies against an unidentified protein having a molecular mass of 56 kDa in three of the six patients. These three ITP patients having autoantibodies against GP IIb/IIIa and against the 56 kDa protein were studied after splenectomy. Two patients, showing disappearance of autoantibodies against these antigens, attained a complete remission, and one patient, with autoantibodies against the 56 kDa protein despite splenectomy, attained only partial remission. These data suggest that autoantibodies against GP IIb/IIIa and against the 56 kDa protein may play a role in platelet destruction in some ITP patients.

Adult↗

Two human monoclonal antiplatelet autoantibodies established from patients with chronic idiopathic thrombocytopenic purpura.

Two human hybridomas secreting antiplatelet autoantibodies were established by somatic cell fusion using splenocytes from two patients with chronic idiopathic thrombocytopenic purpura (ITP). These monoclonal antibodies, HT7F and HT8C, were of the IgM isotype and reacted with autologous and allogeneic platelets fixed with paraformaldehyde (PFA). They also bound to fresh platelets. An elution study showed that eluates from allogeneic platelets reacted with autologous platelets. These results indicated that HT7F and HT8C were autoantibodies recognizing a site on the platelet surface. Both monoclonal antibodies were able to induce complement activation in vitro. HT7F was demonstrated to bind to a platelet protein having a molecular mass of 105 kDa under both nonreducing and reducing conditions. No human hybridoma synthesizing antibody against 105 kDa platelet protein has been reported to date. These antibodies may play a role in the pathogenesis of thrombocytopenia in some ITP patients.

Adult↗

Demonstration of the heterogeneity of epitopes of the platelet-specific alloantigen, Baka.

It is well known that the platelet-specific alloantigen, Baka is carried on glycoprotein (GP) IIb, but little is known about the biochemical characteristics of its epitopes. To clarify the characteristics of the epitopes, we examined the interaction of four anti-Baka sera (Yam, Lin, Kl and MO) with their epitopes, either with or without modifications by sodium dodecyl sulphate (SDS) and/or neuraminidase. By immunoprecipitation, all four antisera bound to the intact GP IIb/IIIa complex from a Baka-positive subject. In contrast, immunoblotting demonstrated that Yam, Lin and Kl bound to SDS-denatured GP IIb, while MO did not. When blotted GP IIb was treated with neuraminidase, Yam and Lin did not bind to desialylated GP IIb, while Kl still did. When the purified GP IIb/IIIa complex or washed platelets were treated first with neuraminidase followed by immunoblotting, the molecular weight of GP IIb decreased from 145 kD to 138 kD; Yam did not bind to desialylated GP IIb, but Kl did. Furthermore, to eliminate the effect of SDS, we examined the interaction of Yam and Lin with neuraminidase-treated platelets using flow cytometry. The results were the same as those obtained using immunoblotting. Our results thus demonstrate that the expression of the Baka epitopes is not uniform and that sialic acid contributes to the expression of some actual allogenic epitopes.

Antigen-Antibody Reactions↗

Acid treatment of platelets as a simple procedure for distinguishing platelet-specific antibodies from anti-HLA antibodies: comparison with chloroquine treatment.

The identification of antibodies to platelet-specific antigens is important for correctly diagnosing neonatal alloimmune thrombocytopenia, posttransfusion purpura and refractoriness due to platelet-specific antibodies. However, the serologic identification of these platelet-specific antibodies is complicated by the presence of anti-HLA antibodies. We examined and compared the diagnostic usefulness of acid-treated and chloroquine-treated platelets for the discrimination of platelet-specific antibodies from anti-HLA antibodies. The viability of acid-treated platelets is 83.4%, which is better than that of chloroquine-treated platelets (52.6%). The antigenicity of HLA class I antigens of acid-treated platelets was significantly reduced compared with that of PBS- or chloroquine-treated platelets. On the other hand, platelet surface glycoprotein Ib and glycoprotein IIb/IIIa, and platelet-specific antigens were stable following acid or chloroquine treatment. Chloroquine-treated platelets were not suitable targets for analysis by immunofluorescence flow cytometry because of nonspecific fluorescence derived from platelet damage. We conclude that acid-treated platelets are more suitable targets than chloroquine-treated platelets for screening for platelet-specific antibodies and also for analyses of the specificity of platelet-specific antibodies.

Antibody Specificity↗