When should iron chelation therapy be considered in patients with myelodysplasia and other bone marrow failure syndromes with iron overload?

Despite the absence of a robust evidence base, there is growing consensus that effective treatment of iron overload leads to decreased morbidity and premature mortality in patients with good prognosis myelodysplastic syndromes (MDSs). Furthermore, new treatment modalities, including disease-modifying therapies (lenalidamide and azacytidine) and reduced intensity conditioning therapies for allogeneic blood stem cell transplants, are offering the prospect of longer survival for patients with traditionally less favourable prognosis MDS, who might also benefit from iron chelation. This article proposes assessment of patients with MDS and related bone marrow failure syndromes to determine suitability for iron chelation. Iron chelation therapy options and monitoring are discussed.

Survival, prognostic factors and rates of leukemic transformation in 381 untreated patients with MDS and del(5q): a multicenter study.

Myelodysplastic syndromes (MDS) with del(5q) are considered to have a benign course of the disease. In order to address the issue of the propensity of those patients to progress to acute myeloid leukemia (AML), data on 381 untreated patients with MDS and del(5q) characterized by low or intermediate I International Prognostic Scoring System (IPSS) risk score were collected from nine centers and registries. Median survival of the entire group was 74 months. Transfusion-dependent patients had a median survival of 44 months vs 97 months for transfusion-independent patients (P<0.0001). Transfusion need at diagnosis was the most important patient characteristic for survival. Of the 381 patients, 48 (12.6%) progressed to AML. The cumulative progression rate calculated using the Kaplan-Meier method was 4.9% at 2 years and 17.6% at 5 years. Factors associated with the risk of AML transformation were high-risk World Health Organization adapted Prognostic Scoring System (WPSS) score, marrow blast count >5% and red-cell transfusion dependency at diagnosis. In conclusion, patients with MDS and del(5q) are facing a considerable risk of AML transformation. More detailed cytogenetic and molecular studies may help to identify the patients at risk of progression.

Energy use in pig production: an examination of current Iowa systems.

This paper compares energy use for different pig production systems in Iowa, a leader in US swine production. Pig production systems include not only the growth and performance of the pigs, but also the supporting infrastructure of pig production. This supporting infrastructure includes swine housing, facility management, feedstuff provision, swine diets, and manure management. Six different facility type × diet formulation × cropping sequence scenarios were modeled and compared. The baseline system examined produces 15,600 pigs annually using confinement facilities and a corn-soybean cropping sequence. Diet formulations for the baseline system were corn-soybean meal diets that included the synthetic AA l-lysine and exogenous phytase. The baseline system represents the majority of current US pork production in the Upper Midwest, where most US swine are produced. This system was found to require 744.6 MJ per 136-kg market pig. An alternative system that uses bedded hoop barns for grow-finish pigs and gestating sows would require 3% less (720.8 MJ) energy per 136-kg market pig. When swine production systems were assessed, diet type and feed ingredient processing were the major influences on energy use, accounting for 61 and 79% of total energy in conventional and hoop barn-based systems, respectively. Improving feed efficiency and better matching the diet formulation with the thermal environment and genetic potential are thus key aspects of reducing energy use by pig production, particularly in a hoop barn-based system. The most energy-intensive aspect of provisioning pig feed is the production of synthetic N for crop production; thus, effectively recycling manure nutrients to cropland is another important avenue for future research. Almost 25% of energy use by a conventional farrow-to-finish pig production system is attributable to operation of the swine buildings. Developing strategies to minimize energy use for heating and ventilation of swine buildings while maintaining pig comfort and performance is a third critical area for future research. The hoop barn-based alternative uses 64% less energy to operate buildings but requires bedding and 2.4% more feed. Current Iowa pig production systems use energy differently but result in similar total energy use. Compared with 1975, current farrow-to-finish systems in Iowa require 80% less energy to produce live market pigs.

Therapy-related myelodysplastic syndrome and acute myeloid leukemia following fludarabine combination chemotherapy.

Fludarabine combination chemotherapy achieves high response rates in chronic lymphocytic leukemia (CLL) and indolent lymphoma. The aim of this study was to investigate the incidence and characteristics of treatment-related myelodysplasia and acute myeloid leukemia (t-MDS/AML) after treatment with fludarabine in combination for lymphoproliferative disorders and identify risk factors for its development. In all, 176 patients treated with fludarabine combination were followed for a median of 41 months (range 6-125 months). In all, 19 cases of t-MDS/AML have been identified for an overall rate of 10.8%. Median overall survival post-t-MDS/AML diagnosis was 11 months. Patients developing t-MDS/AML included 11/54 with follicular lymphoma (FL) (crude rate 20.4%), 5/82 with CLL (6.1%) and 3/24 with Waldenstrom macroglobulinemia or marginal zone lymphoma (12.5%). Most patients had other cytotoxic treatments (median 4, range 0-7) but three with FL had fludarabine combination as their only line of treatment. Of the eleven patients (6.3%) who received mitoxantrone with their first fludarabine combination, four (36.4%) developed t-MDS/AML (P=0.007). There was a trend toward prior cytotoxic therapy increasing the risk for t-MDS/AML (P=0.067). Fludarabine combination chemotherapy is associated with a moderate risk of t-MDS/AML particularly when combined with mitoxantrone. This complication should be considered when evaluating the potential benefit of this treatment in lymphoproliferative disorders.

Nonsolar energy use and one-hundred-year global warming potential of Iowa swine feedstuffs and feeding strategies.

Demand for nonsolar energy and concern about the implications of fossil fuel combustion have encouraged examination of energy use associated with agriculture. The United States is a global leader in pig production, and the United States swine industry is centered in Iowa. Feed is the largest individual input in pig production, but the energy consumption of the Iowa swine feed production chain has yet to be critically examined. This analysis examines nonsolar energy use and resulting 100-yr global warming potential (GWP) associated with the swine feed production chain, beginning with cultivation of crops and concluding with diet formulation. The nonsolar energy use and accompanying 100-yr GWP associated with production of 13 common swine feed ingredients are estimated. Two diet formulation strategies are considered for 4 crop sequence x ingredient choice combinations to generate 8 crop sequence x diet formulation scenarios. The first formulation strategy (simple) does not include synthetic AA or phytase. The second strategy (complex) reduces CP content of the diet by using L-lysine to meet standardized ileal digestibility lysine requirements of pigs and includes the exogenous enzyme phytase. Regardless of crop sequence x diet formulation scenario, including the enzyme phytase is energetically favorable and reduces the potential excretion of P by reducing or removing inorganic P from the complete diet. Including L-lysine reduces the CP content of the diet and requires less nonsolar energy to deliver adequate standardized ileal digestible lysine than simply feeding soybean meal. Replacing soybean meal with full-fat soybeans is not energetically beneficial under Iowa conditions. Swine diets including dried distillers grains with solubles and crude glycerol require approximately 50% more nonsolar energy inputs than corn-soybean meal diets or corn-soybean meal diets including oats. This study provides essential information on cultivation, processing, and manufacture of swine feed ingredients in Iowa that can be coupled with other models to estimate the nonsolar energy use and 100-yr GWP of pig production.

Current status of new drugs for the treatment of patients with multiple myeloma.

Multiple myeloma, a malignant disorder of plasma cells, is the second most common haematological malignancy. Although treatable, multiple myeloma remains incurable in virtually all cases, with a median survival of 3-4 years. Fortunately for patients with this disease, traditional treatment paradigms have been challenged with the emergence of a number of new therapies entering clinical practice over the last 6 years. In this review, we focus on the use of thalidomide (Thalidomide Pharmion; Boulder, CO, USA), lenalidomide (Revlimid; Celgene Corporation, Summit, NJ, USA) and bortezomib (Velcade; Janssen Pharmaceutica N.V., Belgium) in the treatment of myeloma. We present the current clinical experience with respect to efficacy and toxicity of these promising new agents and how the incorporation of these drugs with traditional therapies may improve the outcome for patients with multiple myeloma.

The 3'-untranslated region of the human estrogen receptor alpha gene mediates rapid messenger ribonucleic acid turnover.

Human estrogen receptor-alpha messenger RNA (hERalpha mRNA) has a relatively short half-life, which was determined to be approximately 5 h in MCF-7 cell line after actinomycin D treatment. The 3'-untranslated region (3'UTR) of hERalpha mRNA was previously shown to completely down-regulate chloramphenicol acetyltransferase activity when present at the 3'-end of chloramphenicol acetyltransferase transcripts, suggesting a destabilizing function of the hERalpha 3'UTR sequence. Chimeric genes composed of a serum-inducible Fos promoter, GH-coding sequences, and different segments of the hERalpha complementary DNA 3'UTR sequence were used to confirm this hypothesis and to localize the RNA region responsible for the destabilizing effect. The presence of the complete hERalpha 3'UTR reduced the half-life of the reporter mRNA from more than 24 to 3 h. When the hERalpha 3'UTR was subdivided into four fragments (UTR1-4), one fragment, UTR2, retained the most ability to down-regulate the reporter mRNA (t1/2 = 4 h). A stretch of four AUUUA motifs within UTR2 was shown not to mediate mRNA destabilization. In contrast, further subdivision of the UTR2 into three parts (UTR2a-c) resulted in the loss of the destabilizing activity. Finally, recombination of two UTR2 subfragments (UTR2a and -b) partially restored this function, indicating a cooperative role among the three UTR2a-c subfragments in the process that leads to destabilization of the hERalpha transcript.

Differentially expressed messenger RNA isoforms of the human estrogen receptor-alpha gene are generated by alternative splicing and promoter usage.

The isolation and characterization of several new human estrogen receptor-alpha (hERalpha) mRNAs are described. Together with those previously identified, they give rise to a total of six hERalpha mRNA isoforms (A-F hERalpha mRNAs). Produced from a single hERalpha gene by multiple promoter usage, all these transcripts encode a common protein but differ in their 5'-untranslated region as a consequence of alternative splicing of five upstream exons (1B-1F). RT-PCR and S1 nuclease mapping analysis of these different hERalpha mRNA isoforms revealed a differential pattern of expression of the hERalpha gene in human tissues and cell types. The A hERalpha mRNA is the main isoform detected in mammary glands or in the tumor cell lines derived from this tissue. In endometrium, the predominant forms are the A and C hERalpha mRNA isoforms, whereas the C and F hERalpha mRNA isoforms are the major forms detected in ovary. Finally, high levels of the E hERalpha mRNA isoform are restricted to the liver with an increased expression in females. Taken together, our results demonstrate that the hERalpha gene is a complex genomic unit exhibiting alternative splicing and promoter usage in a tissue-specific manner.

Systematic genomic screening and analysis of mRNA in untranslated regions and mRNA precursors: combining experimental and computational approaches.

MOTIVATION: The untranslated regions (UTRs) of mRNA upstream (5'UTR) and downstream (3'UTR) of the open reading frame, as well as the mRNA precursor, carry important regulatory sequences. To reveal unidentified regulatory signals, we combine information from experiments with computational approaches. Depending on available knowledge, three different strategies are employed. RESULTS: Searching with a consensus template, new RNAs with regulatory RNA elements can be identified in genomic screens. By this approach, we identify new candidate regulatory motifs resembling iron-responsive elements in the 5'UTRs of HemA, FepB and FrdB mRNA from Escherichia coli. If an RNA element is not yet defined, it may be analyzed by combining results from SELEX (selective enrichment of ligands by exponential amplification) and a search of databases from RNA or genomic sequences. A cleavage stimulating factor (CstF) binding element 3 of the polyadenylation site in the mRNA precursor serves as a test example. Alternatively, the regulatory RNA element may be found by studying different RNA foldings and their correlation with simple experimental tests. We delineate a novel instability element in the 3'UTR of the estrogen receptor mRNA in this way. AVAILABILITY: Strategy, methods and programs are available on request from T.Dandekar. CONTACT: dandekar@embl-heidelberg.de

Improved efficiency for primer extension by using a long, highly-labeled primer generated from immobilized single-stranded DNA templates.

Primer extension is one of the most common methods used to measure the amount and size of RNAs. We demonstrate that the sensitivity and the specificity of this method are improved considerably by using a highly-labeled single-stranded DNA generated from a biotinylated single-stranded DNA template, as a long specific primer in the reverse transcription reaction. This new approach allows the detection of transcripts with a low expression level from microgram quantities of total RNA.

Detection of both the normal and mutant alleles in single cells of individuals heterozygous for the sickle cell mutation--prelude to preimplantation diagnosis.

As a preliminary step to preimplantation diagnosis of sickle cell disease in unfertilized eggs or 8-cell embryos of heterozygous parents, we established quality control for detection of the mutant and normal alleles of the beta-haemoglobin gene using single buccal cells. Efficient polymerase chain reaction (PCR) amplification of a 680 base pair sequence of the beta-globin gene spanning the site of the sickle cell mutation was obtained for 79 per cent of single heterozygous cells. In 71 per cent of cases, both alleles were detected. With this current efficiency, we predict that a clinical preimplantation diagnosis at the 8-cell embryo stage could be carried out safely and reliably for a couple at risk of transmitting sickle cell disease to their children.

Flecainide acetate for conversion of acute supraventricular tachycardia to sinus rhythm.

The efficacy of intravenous flecainide acetate (maximum 2 mg/kg or 150 mg given at a rate of 15 mg/min) was assessed in patients with acute supraventricular tachycardia (SVT) (within 24 hours). Fifty patients were studied, 46 with spontaneous SVT and 4 with induced SVT at electrophysiologic assessment. Conversion to sinus rhythm was achieved within 45 minutes in 76%: in 25 patients with atrial fibrillation (76% conversion), 15 with atrioventricular (AV) nodal or AV reentrant tachycardia (100% conversion) and 10 with atrial flutter or atrial reentrant tachycardia (40% conversion). Adverse effects were noted in 21 patients (42%): paresthesia in 9, drowsiness in 8, nausea in 2, accelerated ventricular rate in 5, ventricular tachycardia in 1, sinus bradycardia in 1 and hypotension in 5. Adverse effects were associated with larger dosage and atrial flutter or atrial reentrant tachycardia. Thus, flecainide acetate is effective in converting to sinus rhythm acute atrial fibrillation and AV nodal and AV reentrant tachycardias, but not atrial flutter or atrial reentrant tachycardia.

The effects of supplemental dietary cholesterol and exercise on blood cholesterol and atherosclerosis in the goat.

The objective of this experiment was to determine the effects of supplemental dietary cholesterol and treadmill exercise on blood plasma cholesterol and development of atherosclerosis in young goats. Eighteen two-week-old goats, assigned to four groups for 22 weeks, were fed 100 g whole milk and, after 14 weeks, 50 g corn and cob meal daily/kg body weight. The four groups received, respectively, 250, 175, 100 and 25 mg cholesterol/kg body weight daily in the milk. From week 10 to week 22 of the experiment half of the goats in each group were exercised on a motorized treadmill at a rate of 6.4 km/h for 15 min daily, five days per week. Addition of cholesterol to the diet increased the mean plasma cholesterol in each of the four groups, but between-group comparisons were statistically significant for only the 250-mg group versus the 25-mg group. Exercise had no effect on plasma cholesterol. Analysis of serial blood samples of 16 of the goats during one day of the experiment indicated no significant diurnal variations. Six males, three exercised and three nonexercised, were sacrificed; all had extensive aortic sudanophilia. Histological preparations from sudanophilic areas of all aortas showed areas of intimal thickening composed of foam cells. These same areas stained strongly for lipid with Oil Red 0. No histological evidence of calcium deposition or fibrous plaques was found.