Reversibility of platelet P2Y12 inhibition by platelet supplementation: ex vivo and in vitro comparisons of prasugrel, clopidogrel and ticagrelor.

Essentials Successful outcome of platelet transfusion depends on specific antiplatelet therapy in use. We assessed if ticagrelor, clopidogrel or prasugrel impacts on donor platelet activity ex vivo. Ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets. This might compromise the effectiveness of platelet transfusion therapy. SUMMARY: Background Platelet transfusion is the conventional approach to restore platelet function during acute bleeds or surgery, but successful outcome depends on the specific antiplatelet therapy. Notably ticagrelor is associated with inadequate recovery of platelet function after platelet transfusion. We examined whether plasma and/or platelets from ticagrelor-treated patients influence donor platelet function, in comparison with clopidogrel and prasugrel. Methods Platelet transfusion was mimicked ex vivo by mixing naïve donor platelet-rich plasma (PRP) or gel-filtered platelets (GFP) in defined proportions with PRP, plasma or GFP from cardiovascular patients receiving standard care including medication with prasugrel, clopidogrel or ticagrelor (n = 20 each). Blood was taken 4 h after the previous dose. HLA2/HLA28 haplotyping let us distinguish net (all platelet) and individual patient/donor platelet reactivity in mixtures of patient/donor platelets, measured by flow cytometry analysis of ADP-induced fibrinogen binding and CD62P expression. Results ADP responsiveness of donor platelets was dramatically reduced by even low (10%) concentrations of PRP or plasma from ticagrelor-treated patients. Clopidogrel and prasugrel were associated with more modest donor platelet inhibition. GFP from ticagrelor-treated patients but not patients receiving clopidogrel or prasugrel also suppressed donor GFP function upon mixing, suggesting the transfer of ticagrelor from patient platelets to donor platelets. This transfer did not lead to recovery of ADP responsiveness of patient's platelets. Conclusion Collectively, these observations support the concept that ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets, which might compromise the effectiveness of platelet transfusion therapy.

Rhesus CE expression on patient red blood cells is an independent prognostic factor for adenocarcinoma of the lung.

OBJECTIVES: The influence of blood group antigens on cancerogenesis is shown for distinct tumor types, yet the impact of Rhesus blood group antigens in lung cancer is not clarified. MATERIALS AND METHODS: To investigate the impact of Rhesus blood groups a non-small cell lung cancer (NSCLC) collective (n = 1047) was analyzed retrospectively. Using a second cohort of n = 340 primarily operated stage I-III NSCLC patients, we evaluated immunohistochemistry of CD47-antibody stained tissue samples in correlation to histopathologic subtype and Rhesus blood group. RESULTS AND CONCLUSION: In 516 of 1047 patients blood group data were available. Seven different RhCE phenotypes were grouped as "··ee," "ccE·," and "C·E·." Adenocarcinoma patients with Rh "··ee" revealed improved overall survival (29 (21.2-36.8) m; HR 1.00 [index]) compared with Rh "ccE·" (19 (1.9-36.1) m; HR 1.76 [1.15-2.70]) and Rh "C·E·" (10 (7.4-12.6) m; HR 2.65 [1.70-4.12]) univariately (P < .001) and multivariately (P < .001). Rh "··ee" showed reduced incidence of CNS-metastasis (P = .014) and metastasis count (P = .032) in stage IV adenocarcinoma. Immunohistochemistry associated CD47-positivity with adenocarcinomas (n = 340, P = .048). In n = 51 cases blood group data were available. The prognostic effect of Rh "··ee" compared with Rh "ccE·" and Rh "C·E·" was stated (P = .001), foremost in CD47-positive adenocarcinomas (Rh "··ee" vs. Rh "ccE·" and Rh "C·E·," P = .008). Inversely Rh "ccE·" or Rh "C·E·" was found beneficial in CD47-negative non-adenocarcinomas (P = .046). Phenotypic RhCE expression may be an independent prognostic factor for overall survival in adeno-NSCLC. We hypothesize an erythrocytic-immunologic interaction with tumor tissue, possibly altered by RhCE and CD47, resulting in a metastatic prone condition.

Reduced intensity conditioning allows for up-front allogeneic hematopoietic stem cell transplantation after cytoreductive induction therapy in newly-diagnosed high-risk acute myeloid leukemia.

There is substantial need to improve the outcome of patients with high-risk acute myeloid leukemia (AML). The clinical trial reported here investigated a new approach of up-front allogeneic hematopoietic stem cell transplantation (HSCT), provided a median of 40 days (range 22-74) after diagnosis, in twenty-six consecutive patients with newly-diagnosed high-risk AML characterized by poor-risk cytogenetics (n = 19) or inadequate blast clearance by induction chemotherapy (IC, n = 7). The median age was 49 years (range 17-68). During IC-induced aplasia after the 1st (n = 11) or 2nd (n = 15) cycle, patients received allogeneic peripheral blood stem cells (PBSC) from related (n = 11) or unrelated (n = 15) donors following a fludarabine-based reduced-intensity regimen. Seventeen patients were not in remission before HSCT with a median marrow blast count of 34% (range 6-70). All patients achieved rapid engraftment and went into remission with complete myeloid and lymphatic chimerism. Grades II to IV acute GvHD occurred in 14 (56%) and extensive chronic GvHD was documented in 8 (35%) patients. The probability of disease-free survival was 61% with only three patients relapsing 5, 6 and 7 months after transplantation, respectively. Up-front allogeneic HSCT as part of primary induction therapy seems to be an effective strategy in high-risk AML patients and warrants further investigation.

Graft clonogenicity and intensity of pre-treatment: factors affecting outcome of autologous peripheral hematopoietic cell transplantation in patients with acute myeloid leukemia in first remission.

A total of 22 patients with acute myeloid leukemia (AML) in first complete remission receiving autologous blood stem cell transplantation (ABSCT) were investigated in order to determine factors affecting outcome. All but two patients had a normal karyotype and received the same high-dose chemotherapy followed by G-CSF-mobilized peripheral blood stem cells after the second (n=5) or third (n=17) course of induction and post-remission chemotherapy, respectively. With a median follow-up of 30 months, the median disease-free survival is 24.1 months. Univariate analysis showed that three chemotherapy cycles before ABSCT were associated with a significant better disease-free survival (P=0.0018) and overall survival (P=0.0033), whereas the presence of an FLT3-mutation (n=6) showed no impact. The number of megakaryocytic progenitors (CFU-MK) infused tended to correlate with primary platelet engraftment (P=0.07) and were predictive for neutrophil (P=0.011) and platelet counts (P=0.009) 180 days after transplantation. Patients receiving a higher amount of CFU-MK had a better event-free survival (P=0.02). Our data suggest that the content of CFU-MK within the graft predicts the quality of hematological recovery and long-term disease control. Additionally, a minimum of three chemotherapy cycles before ABSCT seems to be associated with an improved outcome.

Dose-reduced conditioning and allogeneic hematopoietic stem cell transplantation from unrelated donors in 42 patients.

PURPOSE: A fludarabine-based "nonmyeloablative" preparative regimen was investigated in 42 patients with hematological malignancies receiving hematopoietic stem cell grafts from unrelated volunteer donors. EXPERIMENTAL DESIGN: Recipient conditioning consisted of fludarabine 30 mg/m(2) on days -6 to -2 and i.v. busulfan 3.3 mg/kg on days -6 to -5. Antithymocyte globuline was added at 2.5 mg/kg i.v. on days -5 to -2. The patients were grafted with bone marrow (n = 13) or peripheral blood stem cells either unmanipulated (n = 20) or CD34+ selected (n = 9). Graft-versus-host disease prophylaxis was performed with cyclosporine A (CsA, n = 12), CsA/methotrexate (n = 12), or CsA/mycophenolate mofetil (n = 18). RESULTS: With a median follow-up of 13 months (range, 5-26 months), the actuarial disease-free survival is 64% and 38% for patients with lymphoid malignancies and standard-risk leukemia compared with only 14% for patients with high-risk disease. The main cause of treatment failure was relapse of disease in high-risk patients (n = 14). An increased incidence of primary (n = 1) or secondary graft-failure (n = 8) was observed (21%). Chimerism analysis of CD56+/CD3--sorted natural killer (NK) cells, available in 10 patients, showed an impaired increase of donor NK cell chimerism between day 10 and 30 after transplantation in three of four patients with graft failure, whereas the percentage of donor NK cells surpassed 75% in all of the six patients with stable engraftment. CONCLUSIONS: Unrelated transplants after dose-reduced conditioning are associated with a higher risk of graft-failure. Pretransplant host immunosuppression has to be optimized to overcome resistance to grafts from unrelated donors after nonmyeloablative conditioning therapy.

Successful preemptive cidofovir treatment for CMV antigenemia after dose-reduced conditioning and allogeneic blood stem cell transplantation.

BACKGROUND: Cidofovir (CDV) is a nucleotide analogue with proven in vitro effects against cytomegalovirus (CMV) and adenovirus and has been successfully used in the treatment of CMV retinitis in AIDS patients. METHODS: We performed a prospective study to evaluate the efficacy of CDV in 17 patients with hematological malignancies after allogeneic blood stem cell transplantation from related (n=3) and unrelated (n=14) donors. Dose-reduced conditioning (DRC) regimen consisted of busulfan (Bu)/fludarabine (Flu) (n=9) and idarubicin/cytosine arabinoside/Flu (n=1). Myeloablative conditioning (MC) was performed with Bu/cyclophosphamide (Cy)/etoposide (Eto) (n=4), Bu/Cy (n=2), and total body irradiation (TBI)/Cy/Eto (n=1). Antithymocyte globulin (ATG) was used in seven patients with DRC and in six patients with MC. In all patients, either the donor, host, or both were CMV IgG positive pretransplant. Indication for therapy was preemptive treatment of primary CMV antigenemia defined as two consecutive positive tests of pp65 antigenemia assay after transplant. In case of response with a decreasing number of pp65-positive leukocytes, CDV was scheduled in a dosage of 5 mg/kg body weight once a week for 2 weeks followed by maintenance therapy every 2 weeks in an outpatient setting. All patients received probenecid and prehydration as recommended. Patients were monitored using an immunostaining assay for pp65 antigen and a qualitative and quantitative CMV polymerase chain reaction (PCR). Success of treatment was defined as negativity for the pp65 antigen. RESULTS: After DRC, nine of ten patients (90%) showed a response with seven of nine revealing a complete clearance of the virus (pp65 negative, qualitative PCR negative). In the remaining two responders, treatment was changed to ganciclovir because of either renal impairment or slow clearance of antigenemia. Only one of seven patients in the MC group experienced a temporary clearance of pp65 antigen. After MC, two patients experienced CMV disease. Treatment-related toxicity rate was moderate with four patients developing reversible renal impairment (creatinine 133-180 micromol/L); one patient with proteinuria and three patients with complaints of nausea and vomiting. CONCLUSION: Our data suggest the feasibility of CDV administration in patients after allogeneic transplantation. In the recommended dose, it might be used successfully for low-risk patients, e.g., after DRC or organ transplantation, in an outpatient setting.

Sequential monitoring of chimerism and detection of minimal residual disease after allogeneic blood stem cell transplantation (BSCT) using multiplex PCR amplification of short tandem repeat-markers.

Sequential analysis of chimerism after allogeneic blood stem cell transplantation (BSCT) has been shown to be predictive for graft failure and relapse. We have explored the impact of a novel approach for the quantitative determination of chimerism using a commercial PCR assay with multiplex amplification of nine STR-loci and fluorescence detection. The feasibility was studied in 121 patients transplanted from related or unrelated donors. Follow-up investigation was performed in 88 patients. Twenty-eight of these patients had received a transplantation after dose-reduced conditioning therapy. Results were compared to data obtained by FISH analysis in a subgroup of patients receiving grafts from sex-mismatched donors. The analysis was possible in all patients, the median number of informative alleles was 4 (range 1-8) compared to 7 (range 1-9) in the related and unrelated situation, respectively. A good correlation was seen in 84 samples from 14 patients analyzed in parallel with STR-PCR and FISH. Decreasing values of donor chimerism were detected prior to or concomitantly with the occurrence of graft failure and relapse of disease in all patients investigated prospectively. Using FACS-sorted material, eg peripheral blood CD34+ cells, the assay permitted the detection of residual recipient cells with high sensitivity (down to one CD34+ Kasumi cell in 40,000 normal WBC). Evaluation of the inter-laboratory reproducibility revealed that in 20 samples analyzed in three different centers, the median coefficient of variation was 2.1% (range 0.7-9.6%). Taken together, the results support the use of the test as a valuable tool in the follow-up of patients undergoing allogeneic BSCT. In cases lacking PCR-detectable disease-specific gene products, this assay may represent an alternative to recently established real-time PCR methods.

Foscarnet--an alternative for cytomegalovirus prophylaxis after allogeneic stem cell transplantation?

Cytomegalovirus (CMV) disease is a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT) and is associated with high morbidity and mortality. Early detection of the disease by antigenemia testing and polymerase chain reaction (PCR) along with pre-emptive antiviral therapy has been shown to be very effective in decreasing the incidence of CMV. We performed an uncontrolled observational study in 21 patients after HSCT (14 related, 7 unrelated donors) to evaluate the efficacy and toxicity of foscarnet administered as prophylaxis for CMV reactivation. Ten patients received bone marrow, and eleven patients received peripheral blood stem cells. All patients received foscarnet prophylaxis to study side effects, incidence of CMV reactivation, CMV disease, and transplant-related mortality. Foscarnet (90 mg/kg) was given every 12 h, day +11 to day +16. Thereafter, foscarnet (90 mg/kg) was given once per day, three times per week until day +60. The incidence of CMV reactivation detected by antigenemia (pp65 antigen) or PCR was 23.8% (5 of 21 patients). Two patients developed CMV disease and one patient died of CMV-pneumonia. Seventeen patients (81%) reported severe side effects, such as gastrointestinal disturbance, headache, and urethritis. In eight patients (38%), the dose of foscarnet had to be reduced and, in six patients (28.5%), foscarnet application was discontinued because of side effects. Compared with other groups, we believe that the potential benefit of foscarnet administration in this early setting is outweighed by the risks of severe toxicity.

A new technique for resecting 'unresectable' liver tumors.

BACKGROUND/PURPOSE: Liver tumors that surround the three major hepatic veins traditionally have been considered unresectable. This report describes an extended atypical left hepatectomy technique for tumors around the major hepatic veins. METHODS: Three children with tumors surrounding the 3 hepatic veins underwent intraoperative evaluation for extended atypical left hepatectomy. The left hepatic artery, left branch of the portal vein, and the 3 hepatic veins are occluded with vascular clamps. Perfusion of the remaining liver is through the right hepatic artery and portal vein into the retrohepatic vena cava via the retro hepatic veins. If the liver remains soft and does not become mottled, division of the 3 hepatic veins and resection of the tumor are carried out. RESULTS: Extended atypical left hepatectomy was successful in 2 children. Bile leak occurred in 1 instance and healed spontaneously. Both patients had transiently elevated serum bilirubin and transaminase levels and an elevated prothrombin time for 2 weeks. Both survived after treatment with chemotherapy. In the third child the liver became tense and mottled, and the procedure was abandoned. CONCLUSIONS: Successful extended atypical left hepatectomy depends on the ability of the retro hepatic veins to adequately drain blood into the vena cava after interruption (clamping) of the main hepatic veins. If the liver becomes mottled and tense the procedure must be abandoned and the patient should be considered for hepatic transplantation.

Congenital cysts of the third and fourth pharyngeal pouches or pyriform sinus cysts.

Cysts arising from the III and IV pharyngeal pouches, although uncommon, are typical in their presentation. They occur in neonates, invariably in the left anterior neck and cause respiratory distress. Excision of the cyst with ligation of the tract at the level of the pyriform sinus is curative.

Encouraging results in the treatment of haemorrhagic cystitis with estrogen - report of 10 cases and review of the literature.

Haemorrhagic cystitis (HC) after allogeneic haematopoietic stem cell transplantation (HSCT) or high-dose cyclophosphamide (CP) chemotherapy is a severe side-effect and can cause significant morbidity and mortality. In this report, we describe the clinical courses of 10 patients with HC and review the literature. The patients were treated with oral conjugated estrogen in an attempt to improve severe haemorrhagic cystitis. In seven patients positive effects were seen, haematuria resolved in all, but residual symptoms of dysuria remained for longer periods. In one patient application of estrogen was interrupted because of hepatotoxicity. Two patients failed all treatment modalities including oral estrogen because of terminal illness. We conclude that in the management of HC the administration of oral conjugated estrogen should be considered.

Stable engraftment after megadose blood stem cell transplantation across the HLA barrier: the case for natural killer cells as graft-facilitating cells.

BACKGROUND: The case of a patient with chronic myelogenous leukemia who underwent transplantation with highly purified CD34+ peripheral blood stem cells from his two-antigen-mismatched mother is reported. No graft-versus-host disease has been observed so far and stable engraftment has been documented until day 100. METHODS: Weekly analysis of chimerism in different cellular subsets was performed using a quantitative polymerase chain reaction assay for nine short tandem repeat markers in leukocytes sorted by fluorescence-activated cell sorting. RESULTS: No donor CD4+ or CD8+ T cells have been detected up to 3 months after transplantation, whereas a rapid increase of donor CD56+ natural killer (NK) cells was observed in parallel with circulating donor CD34+ progenitors and myeloid cells. CONCLUSIONS: Because the graft contained virtually no T and NK cells, we believe the rapid in vivo generation of NK cells supported stable engraftment across the HLA barrier. The differentiation of CD34+ progenitors into NK cells might be a distinct feature of megadose stem cell transplants.

Treatment of patients with low-risk myelodysplastic syndromes using a combination of all-trans retinoic acid, interferon alpha, and granulocyte colony-stimulating factor.

Used as single agents, ATRA, G-CSF, and IFN-alpha have shown a moderate benefit in patients with low-risk MDS, with a response rate of 10%. The aim of the present study was to evaluate the efficacy of a combination of these agents. The effect on hemoglobin (Hb), platelets, and absolute neutrophil count (ANC), as well as on transfusion frequency, was examined in 25 patients with MDS (11 RA, four RARS, eight RAEB, two CMML). The median age was 61 years (range 44-81), and the male/female ratio was 14/11. Treatment consisted of ATRA at 25 mg/m2/day p.o. for months 1, 3, 5, 7, 9, and 11, IFN-alpha at 1.5 MIU twice a week s.c. for 52 weeks, and, in patients with initial ANC <500/microl, G-CSF at 100-480 microg daily s.c. according to the degree of ANC. The duration of therapy was scheduled for 12 months. Two patients achieved ongoing CR (+19 months; +16 months), one patient with RA after 3 months and one with CMML after 7 months of treatment. In all patients, the mean ANC increased significantly from 1400+/-200/microl before the start of therapy to 3500+/-600/microl at the end of treatment (p=0.025). In two patients an increase of Hb was observed, and one patient ceased to require transfusions. In an additional patient with RA and 5q-syndrome, the platelet count normalized following administration of ATRA/IFN-alpha, increasing from 89,000/microl to 293,000/microl. The eight RAEB patients were nonresponders. We conclude that therapy with ATRA, IFNalpha, and G-CSF is effective in approximately 35% of low-risk MDS patients (in this study: six of 17) and may induce complete remission in individual cases.

Mycophenolate mofetil and cyclosporine as graft-versus-host disease prophylaxis after allogeneic blood stem cell transplantation.

BACKGROUND: Mycophenolate mofetil (MMF) is an inhibitor of purine nucleotide de novo synthesis leading to impaired proliferation of activated lymphocytes. Studies in animals show a synergistic effect of MMF and cyclosporine (CsA) in preventing acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation. We performed a pilot study evaluating the feasibility of the combined application of MMF and CsA as GVHD prophylaxis after allogeneic blood stem cell transplantation. Toxicity and the bioavailability of MMF in this setting were investigated. METHODS: Fourteen patients who had received grafts from HLA-compatible siblings received 2 g of oral MMF from day 1 to 14 combined with intravenous CsA at 4 mg/kg starting at day-1. Plasma levels of mycophenolic acid (MPA) and its glucoronide were measured by high-performance liquid chromatography. Fifteen patients treated with a combination of CsA and methotrexate at the same institution were referred to as the control group. RESULTS: Trilineage engraftment was achieved in all study and control patients. Acute GVHD > or = grade II was observed in 46.5% and 60% of the study and control patients, respectively. No major differences in the rate of acute toxicities were detectable. The mean trough blood level of MPA in 10 patients was 0.28 microg/ml, and 5.7 microg/ml for MPA glucoronide. Reduced peak levels of MPA indicate a reduced absorption rate of MMF in the early posttransplant phase. CONCLUSIONS: The combined administration of MMF and CsA was shown to be feasible in patients after allogeneic blood stem cell transplantation. Because of the decreased bioavailability of MMF, dose-finding studies for an intravenous formulation are warranted.

IL-3 in the clinic.

Since the cloning of human interleukin 3 (IL-3) in 1986 [1] and the demonstration of its proliferative effects on multiple hematopoietic progenitor cells, IL-3 has been widely studied to treat different states of bone marrow failure or hematologic malignancies, to mobilize or expand hematopoietic progenitor cells for transplantation, and to support engraftment after bone marrow transplantation. However, no condition for the clinical use of IL-3 has been established so far despite its theoretical advantages as an early-acting cytokine and in contrast to erythropoietin (EPO), G-CSF, or GM-CSF all of which have already been approved for several clinical modalities. Here we shortly review our current knowledge about the effects of IL-3 on the molecular and cellular level, summarize recent clinical studies with IL-3, and discuss further perspectives for the use of this cytokine.

Air rifles--lethal weapons.

Modern air rifles are very powerful and potentially dangerous, yet they are sold without a license because they are considered toys. We report on 16 patients who were shot with air rifles. Nine of these patients were treated in the last 3 years. Seven patients sustained injuries to the chest and upper back. The BB (ball bearing) penetrated the aorta of two patients, one of whom died. One of two patients shot in the abdomen had injuries to the iliac artery and the colon. Three patients were shot in the head and neck, three in the extremities, and one through the penis. Particularly alarming to us is the fact that nine patients had been shot intentionally after minor arguments with other children. The assailants were neighborhood children in seven cases, a friend in five, and a sibling in two.

Changes in erythroid progenitor cell and accessory cell compartments in patients with myelodysplastic syndromes during treatment with all-trans retinoic acid and haemopoietic growth factors.

Differentiation induction therapy is used in myelodysplastic syndromes (MDS) to improve maturation defects and to restore impaired function of malignant cells. To this end, 18 patients with MDS received either a combination therapy consisting in study 1 of all-trans retinoic acid (ATRA) and granulocyte-colony stimulating factor (G-CSF), or in study 2 of a combination with ATRA, G-CSF, erythropoietin (Epo) and tocopherol. The ANC increased in 19/20 patients in both studies, whereas an increase in haemoglobin concentration, platelet counts or reduction of transfusion requirement was seen in only 8/20 patients, correlating strongly with good BFU-E growth (P < 0.001). To assess the role of accessory cells in the modulation of the haemopoietic response to treatment, we analysed the capacity of peripheral blood monocytes to secrete cytokines (IL-1 beta, IL-6, IL-8, TNF alpha). Secretion of all cytokines was significantly reduced before therapy when compared with healthy controls, but increased during therapy, reaching normal levels for IL-8. These data indicate that a combination therapy with ATRA and cytokines improves impaired cytokine secretion from monocytes and induces a multilineage clinical response in a subgroup of MDS patients characterized by an almost intact erythroid compartment. In contrast, induction of TNF alpha might be responsible for treatment failure.

Effect of long-term treatment with recombinant human interleukin-3 in patients with myelodysplastic syndromes.

In a phase II study, involving nine patients with refractory anemia or refractory anemia with ring sideroblasts, the effects of treatment with recombinant human interleukin-3 (IL-3) on hematopoietic function were assessed. Doses of IL-3 ranging from 60 micrograms/m2 during weeks 1-6 to 125 micrograms/m2 during weeks 7-12 were administered as subcutaneous bolus injections three times per week for 12 weeks. Platelet counts increased in six patients. Platelet increase correlated with stable or decreased serum tumour necrosis factor alpha (TNF-alpha) levels, while an increase of TNF-alpha levels during IL-3 therapy occurred in patients with no change or a decrease of platelet counts. Leukocyte counts increased in two patients and reticulocytes in three, without an effect on hemoglobin levels. Morphological analysis of the bone marrow revealed an expansion of the myeloid compartment in seven of eight evaluable patients, mainly due to stimulation of the precursor cells. No improvement of the in vitro growth of hematopoietic progenitor cells was observed. Sequential cytogenetic analyses indicate that IL-3 treatment does not act preferentially on either the cytogenetically abnormal or the normal clones. These results suggest that long-term treatment with low-dose IL-3 stimulates megakaryopoiesis with increase of platelet counts, but that additional later-acting cytokines probably will be required to augment neutrophil and erythrocyte counts.

Simple technique for determination of the correct length of percutaneous tunnelled catheters in neonates and children.

A simple technique for determining the correct catheter length in percutaneous tunnelled catheters in infants and young children has been devised that virtually guarantees accurate catheter tip placement. Sixty-six patients, aged newborn to 5 years (mean, 1.6 years) have successfully undergone this technique. It is safe, simple, precise, quick, and cost effective. It requires only a hemostat, a suture, and the supplies provided in the prepackaged catheter kit. This technique should be used whenever a percutaneous technique for accessing the vein is used and fluoroscopy is available.

[Antiarrhythmic active amidinohydrazones of substituted benzophenones. 4. The photoisomerization of (Z)- and (E)-2-amino-5-chlorobenzophenone amidinohydrazones and the corresponding (E)-N-phenylamidinohydrazone]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 4. Mitteilung: Untersuchungen zur Photoisomerisierung von (Z)- und (E)-2-Amino-5-chlorbenzophenonamidinohydrazon sowie des entsprechenden (E)-N-Phenylamidinohydrazons.

The title compounds undergo a photoisomerization by irradiation. If the E-isomers are irradiated by light of a wavelength of an absorption maximum typical for them, they can be converted quantitatively to the corresponding Z-isomers. In case that the synthesis of analogs of the title compounds give only one configurational isomer, sometimes the missing one can be obtained by photoisomerization.