High-dose etoposide and cyclophosphamide without bone marrow transplantation for resistant hematologic malignancy

Seventy-five patients with resistant acute leukemia or lymphoma received high-dose cyclophosphamide and etoposide to explore the activity of this combination in resistant hematologic malignancies, and to determine the maximum doses of these drugs that can be combined without bone marrow transplantation. Etoposide was administered over 29 to 69 hours by continuous infusion corresponding to total doses of 1.8 g/m2 to 4.8 g/m2. Cyclophosphamide, 50 mg/kg/d, was administered on 3 or 4 consecutive days total 150 to 200 mg/kg ideal body weight). At all dose levels myelosuppression was severe but reversible. Mucosal toxicity was dose-limiting with the maximum tolerated dose level combining etoposide 4.2 g/m2 with cyclophosphamide 200 mg/kg. Continuous etoposide infusion produced stable plasma levels that were lower than would be achieved after administration by short intravenous infusion, and this could explain our ability to escalate etoposide above the previously reported maximum tolerated dose. There were 28 complete (35%) and 12 partial (16%) responses. Median duration of complete response (CR) was 3.5 months (range 1.1 to 20+). Seventeen of 40 patients (42%) with acute myelogenous leukemia (AML) achieved CR, including 6 of 20 (30%) with high-dose cytosine arabinoside resistance. We conclude that bone marrow transplantation is not required after maximum tolerated doses of etoposide and cyclophosphamide. This regimen is active in resistant hematologic neoplasms, and the occurrence of CR in patients with high-dose cytosine arabinoside-resistant AML indicates a lack of complete cross-resistance between these regimens.     

Energetics and Mechanism of Conformational Transitions of Protein‐Like NIPAM‐Sodium Styrene Sulfonate Copolymers in Aqueous Solutions

Protein‐like and random NIPAM‐sodium styrene sulfonate copolymers of similar composition have been prepared by radical polymerization in water at temperatures above and below the LCST of PNIPAM, respectively. Thermal transitions of the copolymers in aqueous solutions have been studied by means of dynamic light scattering, viscometry, and high‐sensitivity differential scanning calorimetry. The phase separation or cooperative conformational transitions without phase separation were observed for the random or the protein‐like copolymers, respectively. Transition temperature, enthalpy, and heat capacity increment of the protein‐like copolymer differed insignificantly from those of the random copolymer of similar composition. The transition heat capacity increments of the protein‐like copolymers revealed that only 10–20% of their NIPAM links participate in the formation of a dense water‐free globule core. The coil–globule transitions of the protein‐like copolymers were described by the thermodynamic three‐state model according to the scheme “random coil?condensed coil?globule”, which is known to simulate the folding mechanism of globular proteins.

     

Early changes in phosphatidylcholine metabolism in human acute promyelocytic leukemia cells stimulated to differentiate by phorbol ester

The HL-60 leukemia cell line derived from a human acute promyelocytic leukemia is stimulated to differentiate into macrophages within 24-28 hr after exposure to the phorbol ester, 12-O-tetradecanoylphorbol-13- acetate (TPA). We studied early alterations (within 90 min of exposure to TPA) in phosphatidylcholine metabolism in HL-60 cells and found that phosphatidylcholine synthesis by methylation is phosphatidylethanolamine was inhibited in a dose-dependent fashion. In contrast, synthesis of phosphatidylcholine from endogenous choline was enhanced and correlated inversely with the degree of inhibition of the methylation pathway. Phorbol ester congeners of TPA caused similar alterations in phosphatidylcholine metabolism in direct relationship to their capacity to induce differentiation in HL-60 cells. Perturbation of phosphatidylcholine metabolism is an early membrane even in TPA- induced HL-60 cell differentiation.     

Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.     

An alternative extrinsic pathway of human blood coagulation

To study the interrelationships of the major human coagulation pathways, factor X activation in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin were added to plasma samples containing 3H-labeled factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin the rate of factor X activation in factor VIII or factor IX deficient plasma was only 10% of the activation rate seen for normal or factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, restored normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these experiments, it is inferred that normal activation of factor X in plasma due to dilute thromboplastin requires factors VII, IX and VIII. An alternative extrinsic pathway that involves factors VII, IX, and VIII may be a major physiologic extrinsic pathway, and this pathway may help to explain the clinical observations of bleeding diatheses in patients deficient in factors IX or VIII.     

Clinical and vascular effects of ACE inhibitor enalapril in combination with thiaside-like diuretic indapamide in hypertensive outpatients. Results of the multicenter trial POEMA

AIM: To evaluate efficacy and safety of a 6-month treatment of 237 patients with arterial hypertension (AH) of degree 1-3 with ACE inhibitor enalapril (mean dose 21.9 +/- 9.0 mg/day), 49.4% of which received adjuvant indapamide (2.5 mg/day), to study effects of this therapy on rigidity of the major arteries by dynamics of pulse wave velocity (PWV) and US rigidity index beta (RIB). MATERIAL AND METHODS: The study included only patients with initially elevated PWV which was detected in 266 (53%) of 501 examinees. RESULTS: Lowering of systolic and diastolic blood pressure (BP) was 16.8 and 14.0% to treatment month 3 and, in addition, 1.6 and 1. 7% to month 6, respectively (p < 0.001). Target BP (< or = 140/90 mm Hg) was achieved in 82.7% patients. During the trial 3 (1.2%) patients withdrew because of severe cough. Slowdown of PWV measured by brachiomalleolar (PWVbm) and carotid-femoral (PWVcf) methods was equal in the course of the trial and made up 2.45 and 6.1% to treatment month 3 (p < or = 0.05 for both) and additional 3.25 and 7.4% to month 6 (p < 0.001 for both), respectively. High PWV normalized completely in 42.6% patients. After 6 months of the trial US RIB decreased by 30.5% (p < or = 0.001). The correlation analysis detected a significant correlation between SAP fall and PWV decrease only during the first 3 months of therapy (r = 0.402, p = 0.005). In month 3-6 the correlation became insignificant (r = 0.28, p = 0.055). CONCLUSION: Combination of enalapril and indapamide is effective and safe in outpatients with arterial hypertension of the first-third degree and baseline high rigidity of the vascular wall. This treatment reduces PWV and rigidity of the major arteries associated with BP lowering (in the treatment month 1-3) and a vasoprotective effect of the drugs.