Influence of surgical or endovascular distal revascularization of the lower limbs on ischemic ulcer healing

AIM

Our aim is to analyze the ability of distal endovascular procedures, performed as first treatment option, to promote ischemic ulcer healing.

METHODS

Retrospective analysis of 91 primary distal procedures, 49 (53.8%) surgical and 42 (46.2%) endovascular, performed consecutively between January 2005 and December 2007 in patients with critical limb ischemia (CLI) and ischemic ulcers. Patient comorbidities, intervention duration time, postoperative hospital stay and complications were recorded. Ischemic ulcer healing time, patency, limb salvage and survival rates were compared between both groups. Data were included in a Cox regression model to determine predictive factors for healing

RESULTS

Endovascular therapy was associated with shorter intervention time (128±53 versus 301±91 min; P=0.001) and postoperative hospital stay (13±13 versus 19±14 days; P=0.05). Surgical procedures were associated with more local complications (28.6% versus 7.1% P=0.01), more readmissions for surgical wound complications (12.2% versus 0% P=0.03) and more early major amputations (16.3% versus 0% P=0.007). Ischemic ulcer healing in endovascular and surgical procedures was 80% versus 83% at 12 months (P=NS). Overall patency, limb salvage, survival and amputation-free survival with healed ulcers at 24 months in endovascular and surgical groups were 82% versus 82% (P=NS), 83% versus 72% (P=NS), 81% versus 79% (P=NS) and 63% versus 56% (P=NS). Diabetes mellitus (HR: 2.86 95% CI [1.44-5.68]), free ambulatory status (HR: 0.57 95% CI [0.33-0.98]) and the presence of severe wounds (HR: 2.73 95% CI [1.40-5.30]) were predictors for ulcer healing.

CONCLUSION

Endovascular and surgical distal procedures had a similar ulcer healing rate and limb salvage. Our experience supports endovascular-first strategy for CLI with tissue loss.

Long-term pleiotropic effect of statins upon nitric oxide and C-reactive protein levels in patients with peripheral arterial disease

OBJECTIVES

Peripheral arterial disease can be regarded as a systemic inflammatory disorder affecting the entire vascular system. In the early clinical stages, it is characterised by the deterioration of endothelial function, which does not progress with the development of the disease. This study analyses the pleiotropic effects upon the plasma nitrite and C-reactive protein (CRP) levels in claudicating patients after 12 months of treatment with statins.

STUDY DESIGN

A prospective randomised controlled translational study was made in patients with Fontaine grade II ischaemia, treated with the best medical treatment with or without statins for 12 months from the time of diagnosis for assessing the pleiotropic effects of those statins.

METHODS

Measurements of plasma high-sensitivity CRP (hsCRP), lipid profile and nitrites were made at baseline and after 1 month and 1 year of treatment with atorvastatin 40 mg/day.

RESULTS

A significant reduction in nitrite levels was observed after 1 month of treatment (11.8±7.8 μM vs 5.7±1.8 μM, p=0.0001), but this effect did not persist after 1 year (11.8±7.8 μM vs 9.4±8.9 μM, p=0.27). HsCRP underwent a significant reduction after both 1 month (7 (2.2-12) vs 3.4 (1.6-5.5), p<0.01) and 1 year of treatment with atorvastatin (7 (2.2-12) vs 2.25 (1.67-6.7), p=0.02). Statin treatment reduced hsCRP levels in 9.64 (95% CI (1.60 to 17.68)) after 1 month and in 9.14 (95% CI (0.18 to 18.47)) after 1 year.

CONCLUSIONS

The long-term biological pleiotropic effects of statins provide information on the role of endothelial function and systemic inflammation in the aetiopathogenesis of peripheral arterial disease. Statins slow endothelial degradation at the start of the disease, with no effects over the long term. These drug substances reduce progressive inflammation throughout the treatment period. This supports the novel hypothesis that endothelial dysfunction is only a disease-triggering phenomenon, while systemic inflammation would be responsible for both the origin and the maintenance of peripheral arterial disease.

Systems biology: a new paradigm for industrial yeast strain development

One of the key challenges for industrial yeast strain development is to obtain a thorough understanding of the biology of yeast and to apply this knowledge to develop novel strains with improved features. The detailed study of individual biological components and the use of metabolic engineering have benefited the development of industrial strains enormously; however, such approaches have failed to describe yeast behaviour in the detail required to reveal the complex interactions operating within such biological systems. How can we accurately describe the biological processes and the interactions that occur during fermentation or cell growth?

A randomized, double-blind, placebo-controlled trial of spironolactone on carotid intima-media thickness in nondiabetic hemodialysis patients

BACKGROUND AND OBJECTIVES

Hemodialysis patients (HD) display high rates of cardiac diseases and mortality. In chronic kidney disease, vascular injury leads to coronary artery disease, heart failure, and stroke. Carotid intima-media thickness (CIMT) measurements are currently widely used in randomized controlled trials (RCTs) to study the efficacy of interventions. An RCT was designed for the assessment of the safety and effectiveness of spironolactone to inhibit the progression of CIMT in HD patients as a primary outcome. Secondary outcomes included measurements of plasma potassium.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

HD patients were randomly assigned to receive 50 mg spironolactone or placebo thrice weekly after dialysis. In between dialysis sessions, plasma potassium concentrations were measured every month. Ultrasonographic measurements of CIMT were done at the beginning of the study and after 2 years.

RESULTS

Fifty-three age- and sex-adjusted patients (30 with drug and 23 with placebo) successfully completed the trial. There were no significant differences between the two groups in all profiles studied at baseline. Measurements of CIMT after 2 years showed a progression in the placebo group, whereas in the spironolactone group a significant decrease or even reversed CIMT was observed. Progression rates (mm/yr) were: common carotid, placebo: 0.06 +/- 0.07, spironolactone: 0.01 +/- 0.04; carotid bifurcation, placebo: 0.15 +/- 0.27, spironolactone: 0.0001 +/- 0.01; internal carotid, placebo: 0.10 +/- 0.12, spironolactone: -0.10 +/- 0.15. No episodes of hyperkalemia were observed, but a slight increase in plasma potassium was found in the spironolactone group.

CONCLUSIONS

Fifty milligrams of spironolactone thrice weekly significantly reduced the progression of CIMT in HD patients.

New structural and functional defects in polyphosphate deficient bacteria: a cellular and proteomic study

Background

Inorganic polyphosphate (polyP), a polymer of tens or hundreds of phosphate residues linked by ATP-like bonds, is found in all organisms and performs a wide variety of functions. PolyP is synthesized in bacterial cells by the actions of polyphosphate kinases (PPK1 and PPK2) and degraded by exopolyphosphatase (PPX). Bacterial cells with polyP deficiencies due to knocking out the ppk1 gene are affected in many structural and important cellular functions such as motility, quorum sensing, biofilm formation and virulence among others. The cause of this pleiotropy is not entirely understood.

Results

The overexpression of exopolyphosphatase in bacteria mimicked some pleitropic defects found in ppk1 mutants. By using this approach we found new structural and functional defects in the polyP-accumulating bacteria Pseudomonas sp. B4, which are most likely due to differences in the polyP-removal strategy. Colony morphology phenotype, lipopolysaccharide (LPS) structure changes and cellular division malfunction were observed. Finally, we used comparative proteomics in order to elucidate the cellular adjustments that occurred during polyP deficiency in this bacterium and found some clues that helped to understand the structural and functional defects observed.

Conclusions

The results obtained suggest that during polyP deficiency energy metabolism and particularly nucleoside triphosphate (NTP) formation were affected and that bacterial cells overcame this problem by increasing the flux of energy-generating metabolic pathways such as tricarboxilic acid (TCA) cycle, β-oxidation and oxidative phosphorylation and by reducing energy-consuming ones such as active transporters and amino acid biosynthesis. Furthermore, our results suggest that a general stress response also took place in the cell during polyP deficiency.

The efficacy of octreotide LAR as firstline therapy for patients with newly diagnosed acromegaly is independent of tumor extension: predictive factors of tumor and biochemical response

Surgical outcome of acromegaly depends on the preoperatory tumor size and extension. Somatostatin analogues are also a highly effective treatment for acromegalic patients. Nevertheless, the response of GH-secreting adenomas to primary medical therapy is variable. The aim of the present study was to evaluate the efficacy of octreotide LAR as primary therapy for acromegalic patients as a function of initial tumor extension. We performed a multicentre, prospective, observational and analytical study recruiting 19 "naive" acromegalic patients (5 microadenomas, 10 intrasellar, and 4 extrasellar macroadenomas). All of them were treated with octreotide LAR for 12 months. Basal GH and fasting IGF-I concentrations, and tumor volume were measured at baseline and after 6 and 12 months of treatment. Six patients withdrew the study. The patients who completed the protocol showed a significant reduction of tumor volume (25+/-23%, Wilk's lambda=0.506, F=4.400, p=0.046) independently of tumor extension at study entry (Wilk's lambda=0.826, F=0.452, p=0.769). A shrinkage >25% of baseline tumor volume was achieved in 8 (42%) patients with no differences between tumor extension subgroups. Basal GH levels (76+/-18%) and fasting IGF-I (52+/-31%) decreased throughout the study. Six (46%) patients normalized their IGF-I levels. Octreotide LAR is an effective first-line treatment for a large group of acromegalic patients independent of initial tumor extension.

Uruguayan experience with cryopreserved arterial homografts

INTRODUCTION

We analyzed the Uruguayan experience with cryopreserved arterial homografts. We studied 55 medical records in the period from June 9, 2000 to April 7, 2007, including 41 from males and 14 from females, ranging from 36-78 years of age. The clinical indications were as follows: Group 1, revascularization of infrainguinal atherosclerotic occlusive disease by bypass due to the lack of availability of a suitable vein (n = 35); Group 2, substitution of an infected prosthetic grafts (n = 15); and Group 3, arteriovenous fistula (AVF) after failure of previous prosthetic loops by repeated thrombosis and/or infection in the absence of a vein (n = 5).

RESULTS

Among Group 1, primary and secondary patency rates were 61% and 71%, respectively at 1 year with 15 complications, 3 infections, 8 thromboses, 2 aneurysms, 1 homograft degradation, and 1 death related to surgery. Among Group 2, the primary and secondary patency rates were 71% and 79%, respectively, at 1 year with 6 patients experiencing complications. Group 3 did not have complications with a primary patency rate of 67% at 1 year.

CONCLUSIONS

The use of cryopreserved arterial homografts is a valid, accessible, and safe alternative in complicated vascular situations. In our country, it is a technology to consider for patients with critical limb ischemia, when the risk of a major amputation is high and it is not possible to have a suitable vein or prosthetic bypass. It can be an excellent alternative for the substitution of infected synthetic bypasses, especially to substitute in situ for an infected aortic graft.

[Cardiovascular assessment of non diabetic patients on hemodialysis]

BACKGROUND

Diabetes mellitus is an important risk factor for cardiovascular complications among patients on hemodialysis. However, the incidence of these complications among non diabetic patients on hemodialysis is not well known.

AIM

To assess the incidence of cardiovascular complications in non diabetic patients on hemodialysis.

PATIENTS AND METHODS

Seventy five non diabetic patients aged 55.6 +/- 17 years (48 males), receiving hemodialysis three times a week were evaluated with laboratory tests, echocardiogram anda carotid ultrasound. In 26 patients, interleukin 6, tumor necrosis factor alpha, and intercellular adhesión molecule (ICAM-1) were also measured. Patients were followed during two years.

RESULTS

The mean lapse of dialysis therapy was 6.5 +/-5 years. The main cause of renal failure was hypertension. Sixty two percent had systolic hypertension, 86% had concentric left ventricular hypertrophy, 43% had atrial dilatation and 60% had calcifications in the thoracic aorta. Compared with normal controls, patients had higher levels of interleukin 6, tumor necrosis factor alpha and ICAM-1. Carotid media thickness was also higher and increased in the two years of follow up. No correlations were found between ventricular hypertrophy and dialysis lapse, packed red cell volume, calcium phosphorus product, parathormone levels or median arterial pressure. No cardiovascular events were recorded during the follow up period.

CONCLUSIONS

Non diabetic patients on chronic hemodialysis have a high frequency of ventricular hypertrophy, carotid media thickening, aortic calcifications and an increase in proinflammatory cytokines.

Differences in response to serotonergic activation between first and higher order thalamic nuclei

Two types of thalamic nuclei have been recognized: first order, which relay information from subcortical sources, and higher order, which may relay information from one cortical area to another. We have recently shown that muscarinic agonists depolarize all first order and most higher order relay cells but hyperpolarize a significant proportion of higher order relay cells. We now extend this result to serotonergic agonists, using rat thalamic brain slices and whole-cell, current- and voltage-clamp recordings from relay cells in various first order (the lateral geniculate nucleus, the ventral posterior nucleus, and the ventral portion of the medial geniculate body) and higher order nuclei (the lateral posterior, the posterior medial nucleus, and the dorsal portion of the medial geniculate body). Similar to the effects of muscarinic agonists, we found that first and most higher order relay cells were depolarized by serotonergic agonists, but 15% of higher order relay cells responded with hyperpolarization. Thus different subsets of higher order relay cells are hyperpolarized by these modulatory systems, which could have implications for the transfer of information between cortical areas.

[Spontaneous dissection of the renal artery and kidney infarction: report of two cases]

We report two previously healthy males aged 33 and 37 years, presenting with severe pain in the right and left part of the abdomen, respectively. An abdominal CT scan showed in both a kidney infarction. An angio-CAT scan showed changes compatible with a fibromuscular dysplasia in the renal arterial wall. An angiography showed an intimal tear or complex dissection flap in both cases. Both had a satisfactory evolution with conservative treatment. The relationship between fibromuscular dysplasia and spontaneous dissection of the renal artery is discussed.

Strengthening Europe's epidemic intelligence capacity: the first collaboration between a European Union Member State and the European Centre for Disease Prevention and Control

Binary file ES_Abstracts_Final_ECDC.txt matches

Coupling kinetic expressions and metabolic networks for predicting wine fermentations

Problematic fermentations are commonplace and cause wine industry producers substantial economic losses through wasted tank capacity and low value final products. Being able to predict such fermentations would enable enologists to take preventive actions. In this study we modeled sugar uptake kinetics and coupled them to a previously developed stoichiometric model, which describes the anaerobic metabolism of Saccharomyces cerevisiae. The resulting model was used to predict normal and slow fermentations under winemaking conditions. The effects of fermentation temperature and initial nitrogen concentration were modeled through an efficiency factor incorporated into the sugar uptake expressions. The model required few initial parameters to successfully reproduce glucose, fructose, and ethanol profiles of laboratory and industrial fermentations. Glycerol and biomass profiles were successfully predicted in nitrogen rich cultures. The time normal or slow wine fermentations needed to complete the process was predicted accurately, at different temperatures. Simulations with a model representing a genetically modified yeast fermentation, reproduced qualitatively well literature results regarding the formation of minor compounds involved in wine complexity and aroma. Therefore, the model also proves useful to explore the effects of genetic modifications on fermentation profiles.

Differences in Response to Muscarinic Activation Between First and Higher Order Thalamic Relays

The mammalian thalamus is composed of two types of thalamocortical relay. First order relays receive information from subcortical sources and relay it to cortex, whereas higher order relays receive information from layer 5 of one cortical area and relay it to another. Recent reports suggest that modulatory inputs to first and higher order relays may differ. We used rat thalamic brain slices and whole cell recordings from relay cells in various first order (the lateral geniculate nucleus, the ventral posterior nucleus, and the ventral portion of the medial geniculate body) and higher order (the lateral posterior, the posterior medial nucleus, and the dorsal portion of the medial geniculate body) relays to explore their responses to activation of muscarinic receptors. We found that, whereas all first order relay cells show a depolarizing response to muscarinic activation, ∼20% of higher order relay cells respond with hyperpolarization. The depolarization is accompanied by an overall increase in input resistance, whereas the hyperpolarization correlates with a decrease in resistance. Because activation of cholinergic brain stem afferents to thalamus increases with increasing behavioral vigilance, the findings suggest that increased vigilance will depolarize all first order and most higher order relay cells but will hyperpolarize a significant subset of higher order relay cells. Such hyperpolarization is expected to bias these relay cells to the burst firing mode, and so these results are consistent with evidence of more bursting among higher order than first order relay cells.

Assimilable nitrogen utilisation and production of volatile and non-volatile compounds in chemically defined medium by Saccharomyces cerevisiae wine yeasts

Surveys conducted worldwide have shown that a significant proportion of grape musts are suboptimal for yeast nutrients, especially assimilable nitrogen. Nitrogen deficiencies are linked to slow and stuck fermentations and sulphidic off-flavour formation. Nitrogen supplementation of grape musts has become common practice; however, almost no information is available on the effects of nitrogen supplementation on wine flavour. In this study, the effect of ammonium supplementation of a synthetic medium over a wide range of nitrogen values on the production of volatile and non-volatile compounds by two high-nitrogen-demand wine fermentation strains of Saccharomyces cerevisiae was determined. To facilitate this investigation, a simplified chemically defined medium that resembles the nutrient composition of grape juice was used. Analysis of variance revealed that ammonium supplementation had significant effects on the concentration of residual sugar, L-malic acid, acetic acid and glycerol but not the ethanol concentration. While choice of yeast strain significantly affected half of the aroma compounds measured, nitrogen concentrations affected 23 compounds, including medium-chain alcohols and fatty acids and their esters. Principal component analysis showed that branched-chain fatty acids and their esters were associated with low nitrogen concentrations, whereas medium-chain fatty esters and acetic acid were associated with high nitrogen concentrations.