Mitigating long-term emissions of landfill aftercare: Preliminary results from experiments combining microbial electrochemical technologies and in situ aeration.

Landfills still represent the main option for waste disposal in many parts of the world. Anyway, they often pose a significant pollution risk and contribute to potential environmental and human health impacts via gaseous and liquid (leachate) emission pathways if not properly managed. Some innovative technologies can help to reduce these emissions, such as in situ aeration and the application of microbial electrochemical technologies (METs). METs are an emerging field that open the possibility to control microbial reactions, enhancing electron flows from electron donors towards electron acceptors. To this end, several materials with different electrochemically-active properties are used, such as electrical conductivity, capacitance, surface electroactivity and charge. The present project named LA-LA-LAND (Landfill electron-Lapping for a LANDscape requalification) was aimed to apply METs to treat leachate-saturated zones in old landfills. A MET prototype was constructed using a granular anode (graphite) and a cylindrical air-cathode (electroactive biochar). The METs were integrated to three identical laboratory-scale landfill bioreactors coupled with the in situ aeration technique, while three control reactors run without MET. The maximum values of current and power density obtained were 0.015 A·m-2 and 0.00035 W·m-2. The influence of the MET system on the organic matter removal was evident in two reactors, where this technology was applied, with respect to the control ones: total organic carbon decreased on average 13%, while it reduced less than 5% in the control reactors. This preliminary experiment pointed out some critical aspects of MET configuration, such as the weakness of the cathode architecture, which was prone to be flooded by leachate, blocking the aeration flux.

Intensive care of patients requiring open abdomen treatment: a case-series analysis.

BACKGROUND: This retrospective overview examines the management of patients with temporary open abdomen (OA). METHODS: The clinical characteristics and intensive care treatment of 34 consecutive patients with OA (1996-2012) were reviewed. RESULTS: Average age was 61 years, SAPS II score 43, SOFA 8. Two patients had non-contaminated abdomen; 12 had intact gut (only 8 later during stay); 7 repaired gut (only later 4); 13 cutaneous stoma (later 14), and 2 entero-atmospheric fistula (later 8+1 entero-enteral). The median ICU stay was 48 [36-94] days. One quarter of the 2376 ICU-days were classified as severe sepsis/septic shock (antibiotics were given for two thirds of the stay); three quarters were with ventilation; in 95% of days sedatives were given (mainly enterally). Continuous cavity lavage was done in three quarters of days; in 3% of days patients were fasted whereas >20 kcal/kg was given for 74% of days; we fed the gut in 95% of fed-days, in half of them combined with parenteral nutrition. Complications are discussed; mortality was 32.4%, limited to the ICU stay. CONCLUSION: The intensive care of patients with OA is challenging but can achieve better outcomes than expected. Continuous abdominal lavage improves the evacuation of contaminated fluid or debris and, coupled with antiseptics and low antibiotic pressure, reinforces the control of infection. The gut can be used for nutrition (even without gastrointestinal continuity), and long-term light sedation (mainly enteral) with minimal impact on perfusion, ventilation and gut motility.

Daily monitoring of biomarkers of sepsis in complicated long-term ICU-patients: can it support treatment decisions?

BACKGROUND: Diagnosis/grading of infection and the systemic response to infection may be difficult on admission to the intensive care unit, but it is even more complicated for severely ill patients with long intensive care stays. The ACCP-SCCM criteria are difficult to apply for such patients, and objective, validated biomarkers would be of great use in this setting. METHODS: Long-term (>6 days) critically ill patients in the general ICU of University Hospital were prospectively enrolled in the study. All patients were assessed daily by the attending physician using the ACCP-SCCM classification. C-reactive protein (CRP, mg/dL), procalcitonin (PCT, ng/mL), and interleukin-6 (IL-6, pg/mL) of daily stored sera were measured after each patient's discharge. After discharge, an independent, overall clinical evaluation and an a posteriori ACCP-SCCM classification were chosen as the reference standard for all comparisons. The assessor was aware of the patient's clinical course but was blinded to levels of biomarkers. RESULTS: We studied clinical variables and biomarkers of 26 patients over a total of 592 patient days. The day-by-day ACCP-SCCM classification of the attending physician overestimated the severity of the inflammatory response to infection. The diagnostic discriminative ability of severe-sepsis/septic-shock for PCT was high (ROC area 0.952 [0.931-0.973]) and had a best threshold value of 1.58 (83.7% sensitivity, 94.6 % specificity). IL-6 had better discriminative ability than CRP, but both were worse than PCT. CONCLUSION: PCT > 0.43 ng/mL could add to the clinical propensity for sepsis vs. SIRS not related to infection. Values higher than 1.58 ng/mL may support the bedside clinical diagnosis of severe-sepsis. PCT between 0.5 and 1.0 suggest tight daily monitoring of clinical conditions and re-evaluation of PCT.

Feasibility of localized immunosuppression: 1. Exploratory studies with glucocorticoids in a biohybrid device designed for cell transplantation.

Emerging biotechnologies, such as the use of biohybrid devices for cellular therapies, are showing increasing therapeutic promise for the treatment of various diseases, including type 1 diabetes mellitus. The functionality of such devices could be greatly enhanced if successful localized immunosuppression regimens could be established, since they would eliminate the many otherwise unavoidable side effects of currently used systemic immunosuppressive therapies. The existence of local immune privilege at some specialized tissues, such as the eye, CNS, or pregnant uterus, supports the feasibility of localized immunomodulation, and such an approach is particularly well-suited for cell transplant therapies where all transplanted tissue is localized within a device. Following the success of syngeneic transplantation in a subcutaneous prevascularized device as a bioartificial pancreas in a rodent model, we now report the first results of exploratory in vivo islet allograft studies in rats using locally delivered glucocorticoids (dexamethasone phosphate and the soft steroid loteprednol etabonate). Following in vitro assessments, in silico drug distribution models were used to establish tentative therapeutic dose ranges. Sustained local delivery was achieved via implantable osmotic mini-pumps through a central sprinkler, as well as with a sustained-delivery formulation for loteprednol etabonate using poly(D,L-lactic) acid (PLA) microspheres. Doses delivered locally were approximately hundred-fold smaller than those typically used in systemic treatments. While several solubility, stability, and implantation problems still remain to be addressed, both compounds showed promise in their ability to prolong graft survival after tapering of systemic immunosuppression, compared to control groups.

Effects of systemic immunosuppression on islet engraftment and function into a subcutaneous biocompatible device.

The aim of this study was to explore the effect of sirolimus (Sir) and tacrolimus (Tac) on islets implanted into a subcutaneous (SC), prevascularized device in syngeneic rats. Animals received a 40-day treatment with Tac and Sir (alone or in combination) starting either on day 0 or 40 days after islet transplantation. Controls received no treatment. A 40-day washout period was performed after immunosuppression (IS). Glycemia and intravenous glucose tolerance tests (IVGTT) were assessed at follow-up. In the control group, 75% of recipients achieved stable normoglycemia after islet transplantation, while none reversed diabetes with any IS regimen started on day 0. Graft dysfunction was irreversible after IS withdrawal. Glucose clearance (IVGTT) was significantly impaired among Tac-treated compared with control groups (P < .05 with IS; P < .01 after washout). Among animals with established grafts, islet dysfunction which occurred under IS treatment persisted after washout in animals treated with Tac and Sir plus Tac. When compared with controls, glucose clearance was significantly impaired in the Tac and Tac plus Sir groups before and after IS (P < .01, Tac; P < 0.01, Tac plus Sir). Sir and Tac showed profound deleterious effects on islet cell engraftment and function, which may hinder the success of implantation into biohybrid devices. Nondiabetogenic IS protocols must be developed for clinical application of islet transplantation into biohybrid devices.

Soft corticosteroids for local immunosuppression: exploring the possibility for the use of loteprednol etabonate for islet transplantation.

Transplantation of pancreatic islets into subcutaneous, neovascularized devices is one of the possibilities explored as part of our search for a cure of diabetes. We have recently reported that syngeneic transplantation in a subcutaneous prevascularized device can restore euglycemia and sustain long-term function in rats and that explanted grafts showed preserved islets and intense vascular networks. Because all of the transplanted tissue is localized within the device, if such a bioartificial pancreas approach is used, localized immunosuppression might provide sufficient protection against rejection to achieve long-term function, while also avoiding the serious systemic side effects and the susceptibility for opportunistic infections that are commonly associated with systemic immunosuppressive therapies as only much smaller and localized doses are needed. Soft steroids are obvious candidates because soft drugs are specifically designed to produce targeted local activity, but no systemic side effects due to prompt metabolic (preferably extrahepatic, e.g., hydrolytic) inactivation. However, local concentrations that are effective for immunosuppression, but non-toxic to insulin-producing beta-cells have to be found, and nontrivial difficulties related to long-term local deliverability have to be addressed. Here, we report preliminary results obtained using in vitro studies with human islets used to establish a tentative therapeutic concentration range together with fully scaled three-dimensional finite element method (FEM)-based Comsol multiphysics computational models that were used to explore various possibilities to achieve and maintain these concentration levels within the device.

Culture medium modulates proinflammatory conditions of human pancreatic islets before transplantation.

A portion of transplanted islets is lost during engraftment as a result of stressful events, involving hypoxia and production of proinflammatory molecules by islets. Two of these molecules (monocyte chemoattractant protein-1, CCL2/MCP-1 and tissue factor, TF) are directly correlated with reduced graft function. We evaluated which factors reduce islet proinflammatory conditions. In particular the effects of different culture media supplemented with proteins or antioxidant agents on CCL2/MCP-1 and TF human islet release were evaluated. We observed that human islets after culture in final wash culture medium (FW) significantly decreased CCL2/MCP-1 release and TF production compared with CMRL and M199. These effects were independent from the type of protein added to the media (human serum, human albumin, fetal calf serum). Glutathione in FW further decreased CCL2/MCP-1 in a dose-dependent manner. Culture conditions can modulate the proinflammatory state of islets, and could be used in clinical islet transplantation to reduce inflammation during engraftment.

Islet isolation for allotransplantation: variables associated with successful islet yield and graft function.

AIMS/HYPOTHESIS: Efficient islet isolation is an important prerequisite for successful clinical islet transplantation. Although progressively improved, islet yield and quality are, however, unpredictable and variable and require standardisation. METHODS: Since 1989 we have processed 437 pancreases using the automated method. The donor characteristics, pancreas procurement, and digestion and purification procedures including a wide enzyme characterisation of these pancreases were analysed and correlated with islet yield and transplant outcome. RESULTS: By univariate analysis, islet yield was significantly associated with donor age (r=0.16; p=0.0009), BMI (r=0.19; p=0.0004), good pancreas condition (p=0.0031) and weight (r=0.15; p=0.0056), total collagenase activity (r=0.22; p=0.0001), adjusted collagenase activity/mg (r=0.18; p=0.0002), collagenase activity/solution volume (r=0.18; p=0.0002) and neutral protease activity/solution volume (r=0.14; p=0.0029). A statistically significant contribution to the variability of islet yield in a multivariate analysis performed on donor variables was found for donor BMI (p=0.0008). In a multivariate analysis performed on pancreas variables a contribution was found for pancreas weight (p=0.0064), and for a multivariate analysis performed on digestion variables we found a contribution for digestion time (p=0.0048) and total collagenase activity (p=0.0001). Twenty-four patients with type 1 diabetes received single islet preparations from single donors. In these patients, multivariate analyses showed that the reduction in insulin requirement was significantly associated with morphological aspects of islets (p=0.0010) and that 1-month C-peptide values were associated with islet purity (p=0.0071). CONCLUSIONS/INTERPRETATION: These data provide baseline donor, digestion and purification selection criteria for islet isolation using the automated method and indicate that the morphological aspect may be a clinically relevant measure of islets on which the decision for transplant can be based.

In vitro modulation of monocyte chemoattractant protein-1 release in human pancreatic islets.

Islet transplantation is a new approach to treat type 1 diabetic patients. Despite its great potential and progressively increasing success rate, islet engraftment still represents an unsolved problem. Only part of the transplanted beta-cell mass survives after infusion due to hypoxia and inflammatory reactions, principally mediated by macrophages. We have demonstrated that human islets release monocyte chemoattractant protein-1 (MCP-1), one of the most powerful macrophage chemokines, which may impair the fate of a transplant. In this study we have attempted to modulate in vitro MCP-1 release by human islets. Human islets isolated using the automated method were cultured in CMRL or M199 standard culture media alone or supplemented with (1) two intracellular kinase inhibitors (10 micromol/L RO8220, a protein kinase C inhibitor, and rcAMP 20 micromol/L, a protein kinase A inhibitor) or (2) two antioxidant and cell-protective agents (vitamin E, vitamin B); or (3) immunosuppressive drugs (0.001 to 10 ng/mL cyclosporine, 0.1 to 100 ng/mL rapamycin, 0.1 to 10 ng/mL tacrolimus, 0.001 to 10 ng/mL mycophenolate acid). We observed that the only culture condition that significantly decreased MCP-1 in human islets were CMRL (31 +/- 12 in CMRL vs 539 +/- 184 pg/mL, in M199, P <.05) or cyclosporine (514 +/- 83 pg/mL in control islet vs 307 +/- 13, 231 +/- 44, 192 +/- 4, 242 +/- 113, 169 +/- 15 pg/mL in islet plus cyclosporine ranging from 0.001 to 10 ng/mL, respectively, P >.05). The capacity of in vitro factors to decrease human islet MCP-1 release suggests strategies to increase the success of islet transplantation.

Identification of in vitro parameters predictive of graft function: a study in an animal model of islet transplantation.

The quality of human islets is one of the factors decisive for the success of human islet transplantation. Several parameters have been proposed to characterize islet quality, but none of them has been able to predict the fate of a transplant. The aim of our study was to correlate a panel of in vitro parameters for islet viability with their in vivo function after transplantation in nude mice. Islets were obtained after enzymatic digestion of a human pancreas; they were purified from exocrine tissue using a continuous-density gradient. Two aliquots of islets (1000 and 2000 islets) were transplanted under the kidney capsule of diabetic nude mice. The animals were followed for 1 month with repeated measurements of blood glucose and body weight. One month after transplantation, mice were killed and their graft harvested for histologic analysis. In parallel we studied in vitro islet viability with propidium iodide and fura-2, their insulin content, their purity, and their insulin response to glucose upon static incubation. Ten islet preparations were transplanted: 3 out of 10 preparations did not restore normoglycemia; 4 out of 10 normalized glycemia only in mice receiving 2000 islets, and 3 out of 10 fully restore normoglycemia in all mice. The purity of preparations (R(2) = 0.63 and 0.85, respectively, with 1000 and 2000 islets) and the insulin content (R(2) = 0.75 with 2000 IE) correlated with transplant success. These data show that purity of islet preparations and their insulin content should be useful parameters for the selection of islet preparations for transplant purposes.

Islet allotransplantation in type 1 diabetic patients.

Islet transplantation was proposed more than 10 years ago as treatment for normalising glucose homeostasis in type 1 diabetic patients. Since the beginning it has aroused great interest among diabetic patients being an easy procedure, burdened by minor complications: islet transplantation in fact consists on a transhepatic percutaneous injection under local anaesthesia. The initial clinical outcomes not came up to expectations, being low the insulin independence rate and the long term graft function in recipients. Recently, thanks to the introduction of new immunosuppression strategies, clinical data greatly improved: insulin independence was reached in all recipients and maintained in more than 70% of them 2 years from the transplant. The need of an immunosuppression therapy limits the indication of islet transplantation to diabetic patients already immunosuppressed for a previous organ transplant or to patients with brittle diabetes, that is not controlled also with the new strategies of insulin treatment, with a poor quality of life and an increased rate of diabetic complications. Other problems are represented by the progressive decrease of graft function during long term follow up, and by the low number of organ donors that limits the number of transplantation feasible per year.

Non-invasive mechanical ventilation in patients with acute cardiogenic pulmonary edema.

AIM: To evaluate the use of noninvasive mechanical ventilation (NIMV) in patients with acute cardiogenic pulmonary edema. DESIGN: prospective study. SETTING: Emergency Department at a University hospital. PATIENTS: 84 patients with acute respiratory distress due to pulmonary edema. Interven-tions: NIMV, using a pressure support mode and positive end-expiratory pressure (PEEP). A "weaning test" to evaluate clinical stability. MEASUREMENTS: heart rate, arterial blood pressure, respiratory rate, arterial blood gases, electrocardiogram and incidence of myocardial infarction before and after NIMV. Mortality and duration of hospital stay were also considered. RESULTS: A total of 84 patients received NIMV with 14+/-3.6 cm H2O pressure support over PEEP of 8.3+/-2.1 cm H2O and FiO2 1. At the end of the study period, 16 patients (19%) were considered "non responders" and required invasive ventilation; 62 patients (74%) were considered "responders" and subsequently transferred to the medical ward. The hospital mortality was 14% and 25% in the "responder" and "non responder" groups, respectively; the length of stay was 15.7+/-10.1 days in the "responder" group vs 16+/-10.6 days in the "non responder" group. We never found new episodes of myocardial infarction related to NIMV. The only significant difference between "responder" and "non responder" patients was arterial blood pressure. CONCLUSIONS: We hypothesize that "non responder" patients, characterized by blood pressure values lower than "responders", are less "cardiocompetent" and thus unable to cope with the increased work of breathing. NIMV avoided Intensive Care Unit admission for 74% of the observed patients.

Cerebral CO2 vasoreactivity evaluation by transcranial Doppler ultrasound technique: a standardized methodology.

OBJECTIVE: In normal subjects cerebral CO2 vasoreactivity is measured during spontaneous hyperventilation, breathholding, or adding CO2 to inspiratory gases. The correlation between CO2 and cerebral blood flow may, however, be invalidated by the effects of a modified respiratory pattern on venous return, sympathovagal balance, and cathecolamine release. Moreover, the duration of the test, usually not considered, may play an important role. This may justify the scattering of values found in literature. We evaluated a new standardized method for overcoming these confounding factors. DESIGN: Experimental. PARTICIPANTS: Twenty-one healthy volunteers. METHODS: Subjects were connected through a mouthpiece to a mechanical ventilator set in the intermittent positive pressure ventilation mode. The ventilator was fed by two 40-1 tanks, one of which contained 5% CO2. The inspiratory CO2 concentration was varied at fixed time intervals from 0% to 5% without modifying ventilator settings. End-tidal CO2 was measured at the mouthpiece. Mean blood velocity (V(m)) and pulsatility index (PI) in the middle cerebral artery were measured by means of transcranial Doppler ultrasound. RESULTS: The test was easily applicable and well tolerated. No hemodynamic alterations were observed during the tests. The correlation between CO2 and V(m) was always linear and highly significant (R2 > 0.8, p < 0.0001). A low intersubject variability was observed. No difference was found between the two hemispheres, nor between the sexes. CONCLUSIONS: The strict standardization of the technique, avoiding hemodynamic interference, may explain the low intersubject variability. The value of this technique in ventilated neurosurgical patients is still speculative, but it might allow the collecting of valuable data together with a reduction in exposure to CO2, and hence cerebral blood flow modifications.

[Respiratory failure caused by myopathy in severe sepsis]. / Insufficienza ventilatoria da miopatia in corso di sepsi severa.

OBJECTIVE: To describe a generalized myopathic disorder occurred in the convalescence phase of illness of a critically ill patient. SETTING: Neurological Intensive Care Unit. PATIENT: A 43-year-old man with acute leukoencephalopathy and severe sepsis complicated by sustained and prolonged cardiovascular, respiratory and renal failure. After 15 days of complete respiratory autonomy, the patient presented an acute ventilatory failure associated with generalized muscle weakness. Neither a relapse of sepsis nor neurological worsening were detected. MEASUREMENTS AND RESULTS: Electromyogram resulted in normal conduction velocity in both motor and sensitive nervous fibers. Muscular biopsy showed marked fiber size variability with several hypotrophic fibers type II fiber grouping, several areas of degeneration-necrosis with macrophage invasion, dishomogeneous oxidative enzymatic activity, no increase in glycogen or lipid content. CONCLUSIONS: These results excluded critical illness polyneuropathy and all the other known myopathies. Prolonged period of sepsis with multiple organ failure can result in a direct generalized myopathy. This possibility should be kept in mind while treating long term critically ill survivors.

[Energy metabolism and metabolite flow from muscle tissue during TPN of trauma patients]. / Metabolismo energetico e flusso di metaboliti dal tessuto muscolare durante TPN di pazienti traumatizzati.

AIM: We evaluated muscle-visceral interorgan flux of substrates in 8 critically ill patients in the flow phase after injury. SETTING: This study was conducted on critically ill patients admitted in ICU. PATIENTS: 8 patients were studied immediately after injury. RESULTS: We measured leg flux for oxygen, amino acids, glucose, lactate pyruvate, keton bodies, free fatty acids (FFA), free and total carnitine, and whole body oxygen consumption, nitrogen (N) balance and 3-methyl hystidine (3MEH) excretion during fasting and the second day of metabolic treatment (10.7 +/- 0.06 g x N x m-2 e 1035.5 +/- 3.9 kcal x m-2 x die). During fast the leg shows a net release of N, pyruvate, FFA and free carnitine while glucose, lactate and keton bodies fluxes are not different from zero. The energy balance of the leg is markedly negative (substrate for 79 kcal x m-2 burned for leg energy requirement and 347 kcal x m-2 released as a such). Assuming the body muscle tissue 4.5 times the leg tissue and knowing whole body energy balance, we were able to assess that the non muscular (visceral) part of the body resulted in a consistently positive energy balance. The metabolic treatment is able to match the energy expenditure and the substrate efflux of the leg (and the whole body muscle tissue). In fact the efflux of amino acids and FFA is reduced pyruvate blunted while glucose is remarkably taken up (the uptake of the whole muscle tissue accounted for 72% of the daily load). At the same time, the treatment blunts leg free carnitine and reduces body 3MEH output. Moreover, the caloric balance of the non muscular part of the body remains positive even if the qualiquantitative uptake of substrates is different from fasting. CONCLUSION: Substrates for energy requirements of visceral tissue came from muscular tissue. The metabolic treatment is able to modulate this process.

Staged lengthening in the prevention of dwarfism in achondroplastic children: a preliminary report.

We present our experience, since 1983, in lower-limb lengthening for the treatment of achondroplasic dwarfism. We stress the importance of our method, staged lengthening, which includes two separate operations on the tibia, at the ages of 5 and 10, and two on the femurs, at the ages of 6 and 12. This method allows an overall increase in height varying from 30 to 35 cm and has the advantage of minimizing complications, since children tolerate the lengthening-related problems far better. In 9 years 28 children have undergone limb lengthening, and six of these patients have now completed the first three stages, obtaining a total increase in length from 18 to 23 cm. We discuss the staged lengthening program, pointing out advantages and disadvantages of the method.