The effects of a fibre-enriched bakery product on glucose, insulin values and appetite. A pilot randomised cross-over trial.

Brewers spent grain (BSG) is a valuable source of arabinoxylans with potential beneficial effects on glucose values. This pilot randomised crossover double-blind trial compared the effects of panettone, a sweet baked-product, enriched with BSG-fibre (p-rich) to unenriched panettone (p-standard) on glucose and insulin blood values and appetite scores. Ten healthy volunteers consumed each food in a random order. Blood variables and appetite scores were assessed at fasting and at different intervals after each food consumption. Glucose values were significantly higher after p-standard intake at 90-min (89.9 ± 16.1 vs 74.6 ± 19.4 mg/dL) and 120-min (81.1 ± 9.85 vs 72.1 ± 14.0 mg/dL). The areas-under-the-curve (AUCs) were lower for both glucose (p = .043) and insulin values (p = .036) with p-rich. At 240-min, satiety was higher (p = .006), and desire-to-eat lower (p = .008) with p-rich; desire-to-eat AUC was lower with p-rich too (p = .029). The integration of a small amount of BSG-derived fibre into a sweet food led to improved glycaemic control and appetite regulation.

Chitosan-based hydrogel to support the paracrine activity of mesenchymal stem cells in spinal cord injury treatment.

Advanced therapies which combine cells with biomaterial-based carriers are recognized as an emerging and powerful method to treat challenging diseases, such as spinal cord injury (SCI). By enhancing transplanted cell survival and grafting, biomimetic hydrogels can be properly engineered to encapsulate cells and locate them at the injured site in a minimally invasive way. In this work, chitosan (CS) based hydrogels were developed to host mesenchymal stem cells (MSCs), since their paracrine action can therapeutically enhance the SC regeneration, limiting the formation of a glial scar and reducing cell death at the injured site. An injectable and highly permeable CS-based hydrogel was fabricated having a rapid gelation upon temperature increase from 0 to 37 °C. CS was selected as former material both for its high biocompatibility that guarantees the proper environment for MSCs survival and for its ability to provide anti-inflammatory and anti-oxidant cues. MSCs were mixed with the hydrogel solution prior to gelation. MSC viability was not affected by the CS hydrogel and encapsulated MSCs were able to release MSC-vesicles as well as to maintain their anti-oxidant features. Finally, preliminary in vivo tests on SCI mice revealed good handling of the CS solution loading MSCs during implantation and high encapsulated MSCs survival after 7 days.

Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil / Efeitos da época sobre os processos ecológicos em viveiros escavados para criação extensiva de tilápias no Sudeste do Brasil

Abstract In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

Resumo No sudeste do Brasil, a criação extensiva e semi-intensiva de tilápias é realizada em viveiros escavados com fluxo contínuo, com a disponibilidade e manejo do fluxo de água diferentes nas épocas chuvosa e seca. Na região, os resíduos de alface são um recurso potencialmente de baixo custo para a tilapicultura. Este estudo examinou os processos ecológicos ocorrendo em três viveiros escavados com fluxo contínuo fertilizados com restos de alface para criação extensiva de tilápias durante as épocas chuvosa e seca. Parâmetros de qualidade de água, plâncton e sedimento foram amostrados mensalmente durante um ano. A análise de fator foi utilizada para identificar os processos ecológicos nos viveiros e elaborar um modelo gráfico do funcionamento do ecossistema dos viveiros durante as duas épocas. Os processos relacionados ao ciclo do nitrogênio mostraram diferenças entre as duas épocas, enquanto que os processos relacionados com o ciclo do fósforo não foram influenciados pela época. As diferenças ecológicas entre os viveiros foram principalmente devido aos efeitos do vento, adição de material orgânico e densidade de estocagem. Diferenças no crescimento das tilápias entre os viveiros relacionaram-se com a densidade de estocagem e os processos ecológicos afetando a disponibilidade de alimento e a competição intraespecífica. A adição dos restos de alface nos viveiros não resultou em efeitos negativos, assim esta prática pode ser considerada um destino alternativo e um recurso de baixo custo para a criação extensiva de tilápias, pelo menos nas quantidades investigadas neste estudo.

Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil

Abstract In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

Resumo No sudeste do Brasil, a criação extensiva e semi-intensiva de tilápias é realizada em viveiros escavados com fluxo contínuo, com a disponibilidade e manejo do fluxo de água diferentes nas épocas chuvosa e seca. Na região, os resíduos de alface são um recurso potencialmente de baixo custo para a tilapicultura. Este estudo examinou os processos ecológicos ocorrendo em três viveiros escavados com fluxo contínuo fertilizados com restos de alface para criação extensiva de tilápias durante as épocas chuvosa e seca. Parâmetros de qualidade de água, plâncton e sedimento foram amostrados mensalmente durante um ano. A análise de fator foi utilizada para identificar os processos ecológicos nos viveiros e elaborar um modelo gráfico do funcionamento do ecossistema dos viveiros durante as duas épocas. Os processos relacionados ao ciclo do nitrogênio mostraram diferenças entre as duas épocas, enquanto que os processos relacionados com o ciclo do fósforo não foram influenciados pela época. As diferenças ecológicas entre os viveiros foram principalmente devido aos efeitos do vento, adição de material orgânico e densidade de estocagem. Diferenças no crescimento das tilápias entre os viveiros relacionaram-se com a densidade de estocagem e os processos ecológicos afetando a disponibilidade de alimento e a competição intraespecífica. A adição dos restos de alface nos viveiros não resultou em efeitos negativos, assim esta prática pode ser considerada um destino alternativo e um recurso de baixo custo para a criação extensiva de tilápias, pelo menos nas quantidades investigadas neste estudo.

EFNA3 long noncoding RNAs induced by hypoxia promote metastatic dissemination.

The presence of hypoxic regions in solid tumors is an adverse prognostic factor for patient outcome. Here, we show that hypoxia induces the expression of Ephrin-A3 through a novel hypoxia-inducible factor (HIF)-mediated mechanism. In response to hypoxia, the coding EFNA3 mRNA levels remained relatively stable, but HIFs drove the expression of previously unknown long noncoding (lnc) RNAs from EFNA3 locus and these lncRNA caused Ephrin-A3 protein accumulation. Ephrins are cell surface proteins that regulate diverse biological processes by modulating cellular adhesion and repulsion. Mounting evidence implicates deregulated ephrin function in multiple aspects of tumor biology. We demonstrate that sustained expression of both Ephrin-A3 and novel EFNA3 lncRNAs increased the metastatic potential of human breast cancer cells, possibly by increasing the ability of tumor cells to extravasate from the blood vessels into surrounding tissue. In agreement, we found a strong correlation between high EFNA3 expression and shorter metastasis-free survival in breast cancer patients. Taken together, our results suggest that hypoxia could contribute to metastatic spread of breast cancer via HIF-mediated induction of EFNA3 lncRNAs and subsequent Ephrin-A3 protein accumulation.

Stable isotope imaging of biological samples with high resolution secondary ion mass spectrometry and complementary techniques.

Stable isotopes are ideal labels for studying biological processes because they have little or no effect on the biochemical properties of target molecules. The NanoSIMS is a tool that can image the distribution of stable isotope labels with up to 50 nm spatial resolution and with good quantitation. This combination of features has enabled several groups to undertake significant experiments on biological problems in the last decade. Combining the NanoSIMS with other imaging techniques also enables us to obtain not only chemical information but also the structural information needed to understand biological processes. This article describes the methodologies that we have developed to correlate atomic force microscopy and backscattered electron imaging with NanoSIMS experiments to illustrate the imaging of stable isotopes at molecular, cellular, and tissue scales. Our studies make it possible to address 3 biological problems: (1) the interaction of antimicrobial peptides with membranes; (2) glutamine metabolism in cancer cells; and (3) lipoprotein interactions in different tissues.

The ghrelin gene products and exendin-4 promote survival of human pancreatic islet endothelial cells in hyperglycaemic conditions, through phosphoinositide 3-kinase/Akt, extracellular signal-related kinase (ERK)1/2 and cAMP/protein kinase A (PKA) signalling pathways.

AIMS/HYPOTHESIS: Pancreatic islet microendothelium exhibits unique features in interdependent relationship with beta cells. Gastrointestinal products of the ghrelin gene, acylated ghrelin (AG), unacylated ghrelin (UAG) and obestatin (Ob), and the incretin, glucagon-like peptide-1 (GLP-1), prevent apoptosis of pancreatic beta cells. We investigated whether the ghrelin gene products and the GLP-1 receptor agonist exendin-4 (Ex-4) display survival effects in human pancreatic islet microendothelial cells (MECs) exposed to chronic hyperglycaemia. METHODS: Islet MECs were cultured in high glucose concentration and treated with AG, UAG, Ob or Ex-4. Apoptosis was assessed by DNA fragmentation, Hoechst staining of the nuclei and caspase-3 activity. Western blot analyses and pharmacological inhibition of protein kinase B (Akt) and extracellular signal-related kinase (ERK)1/2 pathways, detection of intracellular cAMP levels and blockade of adenylyl cyclase (AC)/cAMP/protein kinase A (PKA) signalling were performed. Levels of NO, IL-1ß and vascular endothelial growth factor (VEGF)-A in cell culture supernatant fractions were measured. RESULTS: Islet MECs express the ghrelin receptor GHS-R1A as well as GLP-1R. Treatment with AG, UAG, Ob and Ex-4 promoted cell survival and significantly inhibited glucose-induced apoptosis, through activation of PI3K/Akt, ERK1/2 phosphorylation and intracellular cAMP increase. Moreover, peptides upregulated B cell lymphoma 2 (BCL-2) and downregulated BCL-2-associated X protein (BAX) and CD40 ligand (CD40L) production, and significantly reduced the secretion of NO, IL-1ß and VEGF-A. CONCLUSIONS/INTERPRETATION: The ghrelin gene-derived peptides and Ex-4 exert cytoprotective effects in islet MECs. The anti-apoptotic effects involve phosphoinositide 3-kinase (PI3K)/Akt, ERK1/2 and cAMP/PKA pathways. These peptides could therefore represent a potential tool to improve islet vascularisation and, indirectly, islet cell function.

Pluripotent stem cells isolated from human amniotic fluid and differentiation into pancreatic beta-cells.

Human amniotic fluid (HAF) contains multipotent stem cells [amniotic fluid-derived stem cells (AFSC)] which can differentiate into a variety of different cell types. Recently, we demonstrated that obestatin, a peptide encoded by the ghrelin gene, exerts anti-apoptotic effects in pancreatic beta-cells and human islets and increases the expression of genes involved in beta-cells differentiation. We investigated whether: 1) AFSC would differentiate into pancreatic beta-cells and 2) obestatin would increase beta-cells differentiation from AFSC. Fluorescence-activated cell sorting analysis and immunocytochemical staining showed the presence of mesenchymal and endothelial markers in AFSC. Real-time PCR evidenced the expression of Octamer binding transcription factor 4 (OCT-4), a marker of pluripotency, during the early differentiation phase. However, the beta-cells differentiation marker duodenal homeobox factor-1 (PDX-1) could not be detected. Obestatin increased OCT-4 expression but had no effect on beta-cells differentiation. These results suggest that, at least under the experimental conditions used in this study, AFSC do not differentiate into beta-cells and obestatin has no additional effect.

[Pneumaturia in a hemodialyzed diabetic. Case report]. / Pneumaturia in emodializzato diabetico. Caso clinico.

The emphysematous cystitis is a rare condition, usually with a favorable prognosis; it is characterized by the presence of air in the bladder lumen and/or wall caused by the fermentation of glucose due to the action of microorganisms. Here the case is described of a hemodialyzed diabetic oligoanuric patient suffering from frequent symptomatic relapses of urinary tract infection, with air in the bladder and reported pneumaturia. The diagnostic workup aimed to exclude the presence of enterovesical fistulas, which are a possible cause of the presence of air in the urinary tract. The air was produced by bacteria isolated in the urine culture. Both the dysuric symptoms and the gas disappeared after appropriate antibiotic treatment.

Primary and immortalised human pancreatic islet endothelial cells: phenotypic and immunological characterisation.

AIMS/HYPOTHESIS: Studies on the biology of the microvascular endothelial cells (MECs) that surround and penetrate the pancreatic islets are hampered by difficulties in isolating and culturing large numbers of pure cells. We aimed to morphologically and functionally characterise primary MECs purified and cultured from human islets, and to establish a simian virus 40 (SV40)-immortalised cell line from these primary cultures. MATERIALS AND METHODS: Human islet MECs were extracted and purified using anti-CD105 coated immunomagnetic beads, and endothelial markers and surface molecules analysed by flow cytometric analysis. An immortalised cell line was then established by using a chimeric adeno5/SV40 virus. RESULTS: Islet MECs expressed classic and specific endothelial markers, a high basal level of intercellular adhesion molecule-1, and low levels of E-selectin and TNF (previously known as TNF-alpha) inducible vascular cell adhesion molecule-1. IFNG (previously known as IFN-gamma) induced expression of HLA class II molecules. The immortalised islet MECs expanded rapidly, exhibited increased DNA synthesis, and were passaged approximately 30 times, without signs of senescence. They retained the endothelial characteristics of the parental cells, and behaved as the primary cells in terms of TNF stimulation of expression of adhesion molecules and support of leucocyte adhesion and transmigration. CONCLUSIONS/INTERPRETATION: The immortalised islet MECs that we have established could effectively represent a substitute for primary counterparts for in vitro studies on the role of the microvasculature in pathophysiological processes involved in type 1 and type 2 diabetes.

Expression of nephrin by human pancreatic islet endothelial cells.

AIMS/HYPOTHESIS: The islet microcirculation has morphological characteristics resembling those of renal glomeruli. Transcription of the nephrin gene, a highly specific barrier protein of the slit diaphragm of podocyte foot processes, has been reported in the pancreas, although its cellular localisation and function remain to be defined. In this study, we purified and characterised microvascular endothelial cells (MECs) isolated from human islets and investigated the expression and distribution of nephrin on these cells. METHODS: Human islet MECs were extracted and purified using anti-CD105-coated immunomagnetic beads and their endothelial characteristics were confirmed by expression of classical endothelial markers and basal high-level expression of intercellular adhesion molecule-1 and TNF-alpha-inducible vascular cell adhesion molecule-1. Nephrin expression was assessed by immunofluorescence, flow cytometric analysis and western blotting on cell lysates, as well as by RT-PCR. RESULTS: Immunofluorescence studies detected nephrin in a fine, punctate, diffuse pattern on cultured islet MECs, and also in human pancreatic islet sections. In both cases nephrin colocalised with endothelial markers. TNF-alpha treatment induced a marked reduction and redistribution of the protein in one or multiple aggregates. Nephrin expression was confirmed by flow cytometry, western blotting and RT-PCR studies. In contrast, nephrin could not be detected at the protein or mRNA level in human macro- and microvascular cells from other sites. CONCLUSIONS/INTERPRETATION: Nephrin is expressed at protein and mRNA levels in islet microendothelium, supporting the hypothesis that islet MECs exhibit distinctive morphological characteristics that indicate functional specialisation of potential pathophysiological importance.

Relationship between central venous pressure and bioimpedance vector analysis in critically ill patients.

OBJECTIVE: To assess the relationship between central venous pressure values and bioelectrical impedance vector analysis (BIVA), which may be used as complementary methods in the bedside monitoring of fluid status. DESIGN: Cross-sectional evaluation of a consecutive sample. SETTING: Intensive care unit of a university hospital. PATIENTS: One hundred and twenty-one consecutive Caucasian, adult patients of either gender, for whom routine central venous pressure measurements were available. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Central venous pressure values and impedance vector components (i.e., resistance and reactance) were determined simultaneously. Total body water predictions were obtained from regression equations according to either conventional bioimpedance analysis or anthropometry (Watson and Hume formulas). Variability of total body water predictions was unacceptable for clinical purposes. Central venous pressure values significantly and inversely correlated with individual impedance vector components (r2 = .28 and r2 = .27 with resistance and reactance, respectively), and with both vector components together (R2 = .31). Patients were classified in three groups according to their central venous pressure value: low (0 to 3 mm Hg); medium (4 to 12 mm Hg); and high (13 to 20 mm Hg). Three BIVA patterns were considered: vectors within the target (reference) 75% tolerance ellipse (normal tissue hydration); long vectors out of the upper pole of the target (dehydration); and short vectors out of the lower pole of the target (fluid overload). The agreement between BIVA and central venous pressure indications was good in the high central venous pressure group (93% short vectors), moderate in the medium central venous pressure group (35% normal vectors), and poor in low central venous pressure group (10% long vectors). CONCLUSIONS: Central venous pressure values correlated with direct impedance measurements more than with total body water predictions. Whereas central venous pressure values >12 mm Hg were associated with shorter impedance vectors in 93% of patients, indicating fluid overload, central venous pressure values <3 mm Hg were associated with long impedance vectors in only 10% of patients, indicating tissue dehydration. The combined evaluation of intensive care unit patients by BIVA and central venous pressure may be useful in therapy planning, particularly in those with low central venous pressure in whom reduced, preserved, or increased tissue fluid content can be detected by BIVA.

Discriminating between body fat and fluid changes in the obese adult using bioimpedance vector analysis.

OBJECTIVE: Conventional body composition methods may produce biased quantification of fat and fat-free mass in obese subjects, due to possible violation of the assumption of constant (73%) tissue hydration. We used an assumption-free, graphical method for interpreting body weight variation in obesity using bioelectrical measurements. DESIGN: 540 obese subjects with body mass index (BMI) > 31 kg/m2 without apparent edema were compared to 726 healthy subjects with BMI < 31 kg/m2 and to 50 renal patients with apparent edema. A subgroup of 48 obese subjects were evaluated again after weight loss (8.6 kg, 3 BMI units) following one-month energy restriction (5 MJ/d, 1200 kcal/d). 32 obese uremic patients were evaluated before and after a dialysis session (3.2 kg fluid removed). Direct measurements obtained from standard 50 kHz frequency bioelectrical impedance analyzer were used as impedance vectors in the Resistance-Reactance Graph. RESULTS: 1) Impedance vectors of obese subjects could be discriminated from those of edematous patients with 91% correct allocation; 2) A significant lengthening of vectors was observed after fluid loss of 3 kg in obese subjects; but 3) A body weight loss of about 9 kg after energy restriction was associated with no vector displacement. CONCLUSION: A different impedance vector pattern was associated with body weight loss in obesity due to fluid removal (vector lengthening) versus an energy-restricted diet (no vector displacement).

Asymmetry of the total body water prediction bias using the impedance index.

Our purpose was to prove on a geometric basis that the bias of total body water (TBW) prediction equations based on the impedance index is far greater in fluid overloading than in dehydration. We used formal evaluation of conventional bioimpedance regression equations in both normal and abnormal body fluid status. We plotted the hyperboloid function generated from a standard prediction equation for the TBW over the resistance-reactance (RXc) plane containing the bivariate tolerance intervals (ellipses) of the healthy population. The equation estimated 35 L TBW for the average man (both sexes) of 170 cm height. Leaving the center of the tolerance ellipses, over which the function was relatively flat, the predicted TBW rapidly increased to absurd values for the shorter vectors, indicating fluid overloading (e.g., > 100 L for R < 170 ohm). Migration of the longer impedance vectors beyond the upper pole of 95% tolerance ellipse, which is in the dehydration region, produced less biased estimates of TBW (e.g., < 22 L for the extreme R values > 850 ohm). Different formulas produced TBW prediction bias of the same order. Due to the hyperbolic shape, functions of the impedance index are critically dependent on the region of the RXc plane where they are calculated and they produce misleading results in patients with fluid overload.

A decision analysis comparing three dosage regimens of subcutaneous epoetin in continuous ambulatory peritoneal dialysis.

Epoetin (recombinant human erythropoietin; EPO) therapy adds a significant cost to the management of end-stage renal disease, the majority of the extra expense being attributable to its acquisition cost. In a Japanese multicentre, randomised, prospective study, a significant dose-dependent response was documented with epoetin given subcutaneously (SC) once a week or once every 2 weeks to patients receiving continuous ambulatory peritoneal dialysis. Three different dosages were studied over 5 months in patients with a haematocrit (Hct) of 0.28 or less, namely 6000U (107 U/kg), 9000U (167 U/kg) and 12,000U (211 U/kg). Epoetin was given weekly for the first 2 months until the target Hct value of 0.33 was reached. The rates of response were 81, 85 and 100% with the 6000U, 9000U and 12,000U regimens, respectively. Subsequently, responders were maintained at the target Hct for an additional 3 months, with the administration frequency eventually being reduced to fortnightly or 4-weekly. Patients in the epoetin 6000U and 9000U groups who did not respond after 2 months' treatment underwent induction and maintenance with the 12,000U regimen. During the maintenance phase, patients receiving the epoetin 6000U and 9000U dosages required weekly (54 and 64%, respectively) or fortnightly (46 and 36%, respectively) injections. Patients receiving the 12,000U regimen were found to require weekly (9%), fortnightly (73%) or 4-weekly (18%) injections. Using these data, we performed a decision analysis that quantitatively incorporated the probability of attaining and maintaining target Hct levels in all patients (i.e. the effectiveness of epoetin), and direct costs as a function of both cumulative doses and injections required in all 3 strategies over 5 months. Decision analysis indicated that the most cost-effective SC epoetin strategy in patients undergoing peritoneal dialysis is epoetin 6000U weekly for 2 months, followed by maintaining the target Hct with weekly or 2-weekly epoetin 6000U for the next 3 months. Nonresponders should restart epoetin therapy using the 12,000U strategy. The 9000U and 12,000U strategies were associated with similar costs, because the economic advantages associated with the lower administration frequency of the 9000U regimen compared with the 6000U regimen were offset by its higher cumulative acquisition cost. In other words, decision analysis indicated that the most cost-effective strategy was to use the lowest effective dose, reserving the highest dosage for patients who do not respond after 2 months. The superiority of this strategy was confirmed by a sensitivity analysis performed on the cost of drug administration, which was varied from zero to $US60 per dose.(ABSTRACT TRUNCATED AT 400 WORDS)