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.     

Marrow transplantation with or without donor buffy coat cells for 65 transfused aplastic anemia patients

Sixty-five multiply transfused patients with severe aplastic anemia were given cyclophosphamide followed by grafts anemia were given cyclophosphamide followed by grafts from HLA-identical siblings. The effect of the administration of viable donor buffy coat cells following the marrow inoculum was evaluated with regard to graft rejection and survival. Results in 43 patients so treated are presented along with those in 22 concurrent patients given marrow alone. Most patients given buffy coat had positive in vitro tests of sensitization indicating a high risk for graft rejection, while all but one of the patients given marrow alone had negative tests. Thirty of the 43 (70%) patients given marrow and buffy coat are alive between 10 and 61 mo (median 36) after grafting; 4 died after graft rejection and 6 with acute or chronic graft-versus-host disease (GVHD). Eleven of the 22 (50%) patients given marrow alone are alive between 29 and 65 mo (median 52); 7 died after graft rejection and 3 with GVHD. The addition of buffy coat cell infusions to the marrow inoculum reduced the risk of rejection and increased survival in the currently reported transfused patients when compared to patients grafted before 1976. However, there was an increased risk of chronic GVHD. Recipients of marrow from female donors survived slightly better (73%) than recipients of male marrow (58%).     

Role of interaction between variants in the PPARG and interleukin-6 genes on obesity related metabolic risk factors

The combined effect of Peroxisome proliferator-activated receptor gamma (PPARG) Pro/Ala and interleukin-6 G174C gene variants, was evaluated in 429 Caucasian subjects in order to determine whether subjects carrying both variants were at different risk for obesity. In particular, the combined contribution of these two variants (both independent and interaction effects) to the total variation of obesity-related factors was estimated. All subjects were genotyped for codon 12 Pro/Ala locus variability and for the interleukin-6-174 C/G promoter polymorphism. Subjects with the Ala variant had significantly lower BMI, insulin resistance, triglyceride levels than those without. Furthermore, subjects with Ala variant had significantly lower IL-6 levels (0.88 +/- 0.9 vs 1.61 +/- 2.25 pg/ml; p = 0.041). In contrast, the IL6-C variant was significantly associated with lower plasma IL-6 and with lower total cholesterol levels but was not significantly associated with any other obesity risk factors. Indeed, subjects carrying both PPARG and IL-6 gene variants, had a clearly more favourable profile of obesity related risk factors than subjects with one variant, having Ala+/C+ carriers lower BMI (22.8 +/- 2.3 vs 24.14 +/- 1.9; f = 5.31; p < 0.005), insulin resistance (1.49 +/- 0.70 vs 2.13 +/- 0.92; f = 4.342; p = 0.038) and triglyceride levels (79.15 +/- 32.9 vs 98 +/- 6.73 mg/dl; f = 3.120; p < 0.005). These findings suggest that the effect of the two genetic variants on 'obesity related' factors is additive.     

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.     

Role of free fatty acids on cardiac autonomic nervous system in noninsulin-dependent diabetic patients: effects of metabolic control

Decreased heart rate variability (HRV) is a risk factor for cardiovascular mortality. Elevated plasma free fatty acid (FFA) levels decrease HRV in healthy subjects. Thus, we investigated the effect of changes in plasma FFA levels on HRV, in non-insulin-dependent diabetes (NIDDM) patients. Thirty NIDDM patients free from diabetic neuropathy volunteered for a study made by two phases. In study A, changes in HRV along a 10% lipid emulsion infusion + heparin (n = 15) or saline infusion (control study; n = 15) were investigated. In study B, all patients (n = 30) underwent further determination of HRV after 3 months of improved metabolic control achieved by intensified insulin treatment. In study A, lipid emulsion infusion increased plasma FFA (P < 0.001) and catecholamine concentrations (P < 0.005), mean arterial blood pressure (P < 0.005), low frequency/high frequency (LF/HF) ratio (P < 0.001). Delta plasma FFA levels correlated with delta LF/HF ratio (r = 0.57; P < 0.02). Along with saline infusion, metabolic and cardiovascular parameters remained unchanged throughout the test. In study B, improved metabolic control lowered fasting plasma glucose (P < 0.005), FFA (P < 0.001), norepinephrine (P < 0.02), epinephrine (P < 0.04), and glycosylated hemoglobin levels (P < 0.001), mean arterial blood pressure(P < 0.05), and LF/HF ratio (P < 0.001). Again percent decline in plasma FFA correlated with the percent change in LF/HF ratio (r = 0.72; P < 0.001). In a multivariate analysis, percent changes in LF/HF ratio were associated with percent changes in plasma FFA independently of gender and percent changes in body mass index, waist/hip ratio, plasma norepinephrine, epinephrine, glycosylated hemoglobin, and daily insulin therapy. Our study demonstrates that changes in plasma FFA levels may have a parallel effect on cardiac sympathetic/parasympathetic nervous system balance in NIDDM patients.     

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.