Thrombopoietin alone stimulates the early proliferation and survival of human erythroid, myeloid and multipotential progenitors in serum-free culture

We examined the effects of recombinant human thrombopoietin (TPO, c-Mpl ligand) on the proliferation and differentiation of human haemopoietic progenitors other than megakaryocytic progenitors using serum-free cultures. TPO alone supported the generation of not only megakaryocytic (MK) but also blast cell (blast) colonies from cord blood CD34⁺ cells. Delayed addition of a cytokine cocktail (cytokines; interleukin (IL)-3, IL-6, stem cell factor, erythropoietin, granulocyte-macrophage colony-stimulating factor, and TPO) to cultures with TPO alone on day 7 induced various colonies including granulocyte-macrophage (GM) colonies, erythroid bursts (E), granulocyte-erythrocyte-macrophage-megakaryocyte (GEMM) colonies. Replating experiments of blast colonies supported by TPO alone for culture with cytokines revealed that approximately 60% of the blast colonies contained various haemopoietic progenitors. Single cell cultures of clone-sorted CD34⁺ cells indicated that TPO supported the early proliferation and/or survival of both primitive and committed haemopoietic progenitors. In serum-free suspension cultures, TPO alone significantly stimulated the production of progenitors for MK, GM, E and GEMM colonies as well as long-term culture-initiating cells. These effects were completely abrogated by anti-TPO antibody. These results suggest that TPO is an important cytokine in the early proliferation of human primitive as well as committed haemopoietic progenitors, and in the ex vivo manipulation of human haemopoietic progenitors.     

Characterization of peripheral blood progenitor cells (PBPC) mobilized by filgrastim (rHuG-CSF) in normal volunteers: dose–effect relationship for filgrastim with the character of mobilized PBPC

Filgrastim (rHuG-CSF)-mobilized peripheral blood progenitor cells (PBPC) in healthy Japanese volunteers were characterized in detail using two clonal cell culture systems and double-colour flow cytometry to detect multilineage colony-forming cells and subsets of CD34⁺ cells. The kinetics of PBPC during the administration of filgrastim was studied, and possible differences in the character of progenitor cells relative to given doses of filgrastim were investigated. Filgrastim was administered subcutaneously to normal volunteers for 7 d at doses of 100, 200 or 400 μg/m² (10 per cohort). Treatment with 100 or 200 μg/m² filgrastim was well tolerated; however, the 400 μg/m² dose level was not completed because of bone pain and myalgia. The treatment strikingly mobilized various types of progenitor cells, including highly proliferative megakaryocytic colony-forming cells. The number of progenitor cells peaked on days 5 and 6. The fold increase of circulating progenitor cells from the baseline value in the volunteers treated with 200 μg/m² filgrastim was more pronounced than in those treated with 100 μg/m². Treatment with 200 μg/m² also released the less mature progenitor cells (i.e. mixed colony-forming cells, CD34⁺/33⁻ cells, and CD34⁺/HLA-DR⁻ cells) into circulation better than the 100 μg/m² dose. These results suggest that daily subcutaneous injection with 200 μg/m² filgrastim for 5 d will effectively mobilize, both qualitatively and quantitatively, PBPC in healthy donors.     

Clonal identification of Burkitt's Lymphoma Arising from Lymphocyte-Predominant Hodgkin's Disease

The occurrence of large cell lymphomas subsequent to, or concurrent with, lymphocyte predominant Hodgkin's disease (LPHD) is a well-documented phenomenon. We present a case of Burkitt's lymphoma of the bladder, occurring after the successful treatment of LPHD of a cervical lymph node. To evaluate the clonal relationship of the two tumours, we amplified the complementarity-determining-region 3 of two samples from paraffin-embedded slides, using the polymerase chain reaction (PCR). The sequences of the PCR products showed 96% homology to each other. These results indicate that the malignant clone of Burkitt's lymphoma arose from the corresponding LPHD.     

Guidelines for the antiviral therapy of hepatitis C virus carriers with normal serum aminotransferase based on platelet counts.

Aim: We aimed to identify the candidates for antiviral therapy, among patients who are hepatitis C virus (HCV) carriers with normal serum aminotransferase (ALT), focused on the inhibition of hepatocellular carcinoma (HCC). Methods: Four hundred and sixty-four HCV carriers with normal serum ALT and 129 HCV carriers with persistently normal ALT (PNALT) and platelet (PLT) counts >/=150 000/muL who received liver biopsies were enrolled. HCV carriers with normal serum ALT were divided into four groups according to their ALT levels (/=150 000/muL or <150 000/muL). Results: In 129 HCV carriers with PNALT, the rate of progression of fibrosis stage was 0.05/year and no HCC was detected during the follow up for 10 years. Approximately 20% of patients with ALT /=150 000/muLwere at stage F2-3; however, approximately 50% of patients with ALT /=31 U/L when we focus on the inhibition of the development of HCC.     

Spectrum of the infective endocarditis in the past five years

One hundred and thirty patients at our Heart Institute with infectious endocarditis during the past 5 years were reviewed to provide an overview of the spectrum of infective endocarditis and to assess the accuracy of echocardiography in detecting the infective valvular and endocardial lesions. Of the 130 patients, 36 (28%) had the previous cardiovascular surgery. The mean age of the patients was 34 years, and only 11% of the patients were over 50 years of age. Of the 94 patients who had no cardiovascular surgery before developing infective endocarditis, 6 underwent urgent surgery, 49 had elective surgery and the remaining 39 were followed up with medical treatment. The mortality rate of the 55 patients who were operated on was 5.5% as against 18.0% in 39 without surgery. Half of the 36 patients who had been operated on before developing endocarditis had prosthetic valves inserted. Of the 5 patients with bioprosthetic valve endocarditis, only one survived as a result of prompt medical and surgical treatment. Streptococci were still commonly found, about 75% in the group without surgery and 50% in the group with surgery. Gram-negative bacilli and fungi were found in patients with prosthetic valve endocarditis. In 61 patients, morphologic abnormalities confirmed at surgery or necropsy were compared with the preoperative echocardiograms. Vegetations were identified preoperatively in 50 (95%) of the 53 valves involved, and valve destruction was correctly predicted in all 23 cases. Mycotic aneurysm was detected preoperatively in only 3 of the 12 patients in whom it occurred. Thirteen patients, in whom vegetation was recorded, were treated successfully with antibiotics alone and they needed no surgical intervention during the 2-year follow up period. The presence of a vegetation in an echocardiography does not necessarily require surgical intervention in itself or predict the ultimate course.     

Coronary artery stenting with high-pressure post-dilation followed by adjunctive thrombolysis after failed coronary angioplasty for acute myocardial infarction: Report of three cases

We successfully implanted coronary stents into refractory reoccluded lesions after failed coronary angioplasty in three patients with acute myocardial infarction (AMI). Lesion location was the proximal left anterior descending coronary artery in two patients and the dominant right coronary artery in one patient. The reference diameters of the lesions were 3.64, 3.33, and 3.50 mm, respectively. A stent with a luminal diameter of 3.0 mm was implanted in all patients. Poststenting dilation of the stent was performed at high pressure (18 atm), and urokinase was administered immediately thereafter. Heparin was administered for 24 h with maintenance of activated coagulation time within 180–200 s. Warfarin was then administered to keep the international normalized ratio within 2.5–3.5. Luminal diameters immediately after stenting were 3.14, 2.89, and 3.26 mm, and those at 1 month after stenting were 3.09, 2.81, and 3.12 mm, respectively, indicating good patency. Our experience in these cases suggests that coronary stenting can be applied after unsuccessful coronary angioplasty in selected patients with AMI. The present report includes informative reference data on diameter, postdilation, adjunctive thrombolytic agent administration, and adequate anticoagulation therapy in coronary stenting in this acute application.     

Allogeneic hematopoietic stem cell transplantation for patients with hemophagocytic syndrome (HPS) in Japan

Seventeen cases (age at onset, 1 month to 18 years; M/F, 9/8) of hemophagocytic syndrome which received allogeneic hematopoietic stem cell transplantation (SCT) in Japan during the period 1988-1998 are reported. The patients consisted of six familial inheritance-proven erythrophagocytic lymphohistiocytosis (FEL), five familial inheritance-unknown and infective agents-unknown HLH (of which two were highly likely to have been FEL with characteristic CNS signs), and six aggressive Epstein-Barr virus (EBV)-related HLH (of which two were natural killer cell-type large granular leukemia/lymphoma-associated hemophagocytic syndrome, EBV-NK-LGLL-HPS). All cases were treated intensively with immuno-chemotherapy, or with chemotherapy before SCT. As sources of SCT, 12 cases received bone marrow cells (sibling six, father one, URD five), two cord blood, two purified CD34-positive cells, and one PBSC. SCTs were successful in all 17 cases, apart from one receiving CD34-positive SCT. Following SCT, four patients relapsed and five died with a median follow-up of 23 months. Among the relapsed cases, the two EBV-NK-LGLL-HPS previously published as successfully transplanted were included. Among the fatal cases, three patients died from relapsed active disease and the remaining two from fatal post-SCT EBV-positive T cell lymphoma and extensive chronic GVHD, respectively. As of the end of September 1998, 10 patients are alive without disease for 3.5 months to 147 months, while two post-SCT patients are still having therapy for residual/recurrent disease. The Kaplan-Meier analysis showed a 2-year event-free survival after SCT as 54.0+/-13.0%.     

Rapid,sensitive detection of myoglobinemia by improved counterimmunoelectrophoresis in cases of acute myocardial infarction

A counterimmunoelectrophoresis technique for detection of serum myoglobin (Mb) was improved using non-ionic polymer dextran. Precipitin lines were graded according to their strength, which was ascertained by radioimmunoassay data. By this method, serum Mb in concentrations of 500 ng./ml. before stain and of 200 ng./ml. after stain were detected. Electrophoretic time was 60 minutes. Among 32 cases of acute myocardial infarction (AMI) whose blood samples were collected within 24 hours after disease onset, precipitin lines were detected in 25 cases (78 per cent) before stain and 31 cases (97 per cent) after stain. Considering the early peak concentration time (approximately 10 hours) of serum Mb after AMI onset, diagnosis becomes more rapid and exact with this method, especially in severe cases.