Physiological adaptation and population dynamics of a nitrifying sludge exposed to ampicillin.

Antibiotics in wastewater treatment plants can alter the physiological activity and the structure of microbial communities through toxic and inhibitory effects. Physiological adaptation, kinetic, and population dynamics behavior of a nitrifying sludge was evaluated in a sequential batch reactor (SBR) fed with 14.4 mg/L of ampicillin (AMP). The addition of AMP did not affect ammonium consumption (100 mg NH4+-N/L) but provoked nitrite accumulation (0.90 mg NO2--N formed/mg NH4+-N consumed) and an inhibition of up to 67% on the nitrite oxidizing process. After 30 cycles under AMP feeding, the sludge recovered its nitrite oxidizing activity with a high nitrate yield (YNO3-) of 0.87 ± 0.10 mg NO3--N formed/mg NH4+-N consumed, carrying out again a stable and complete nitrifying process. Increases in specific rate of nitrate production (qNO3-) showed the physiological adaptation of the nitrite oxidizing bacteria to AMP inhibition. Ampicillin was totally removed since the first cycle of addition. Exposure to AMP had effects on the abundance of bacterial populations, promoting adaptation of the nitrifying sludge to the presence of the antibiotic and its consumption. Nitrosomonas and Nitrosospira always remained within the dominant genera, keeping the ammonium oxidizing process stable while an increase in Nitrospira abundance was observed, recovering the stability of the nitrite oxidizing process. Burkholderia, Pseudomonas, and Thauera might be some of the heterotrophic bacteria involved in AMP consumption.

Clinical and cost outcomes of a polyethylene glycol (PEG)-coated patch versus drainage after axillary lymph node dissection in breast cancer: results from a multicentre randomized clinical trial.

BACKGROUND: The aim of this study was to compare the clinical outcomes between breast cancer patients who underwent axillary lymph node dissection with postoperative management using a polyethylene glycol-coated patch versus axillary drainage. The direct costs associated with both postoperative management strategies were also evaluated. METHODS: This was a multicentre RCT in women with breast cancer who underwent axillary lymph node dissection (ClinicalTrials.gov identifier: NCT04487561). Patients were randomly assigned (1 : 1) to receive either drainage or a polyethylene glycol-coated patch as postoperative management. The primary endpoints were the need for an emergency department visit for any event related to the surgery and the rate of seroma development. RESULTS: A total of 227 patients were included , 115 in the patch group (50.7 per cent) and 112 (29.4 per cent ) in the drainage group. The incidence of emergency department visits was significantly greater for patients with drainage versus a polyethylene glycol-coated patch (incidence rate difference 26.1 per cent, 95 per cent c.i. 14.5 to 37.7 per cent; P < 0.001). Conversely, the seroma rate was significantly higher in the polyethylene glycol-coated patch group (incidence rate difference 22.8 per cent, 95 per cent c.i. 6.7 to 38.9 per cent; P < 0.0055). Compared with drainage, using a polyethylene glycol-coated patch resulted in cost savings of €100.41 per patient. An incremental cost-effectiveness ratio analysis found that drainage was associated with an incremental cost-effectiveness ratio of €7594.4 for no need for hospital admission and €491.7 for no need for an emergency department visit. CONCLUSION: Compared with patients who received drainage after axillary lymph node dissection, the use of a polyethylene glycol-coated patch resulted in a higher rate of seroma, but a lower number of postoperative outpatient or emergency department visits and thus a reduction in overall costs.

Long-term post-storage reactivation of a nitrifying sludge in a sequential batch reactor: physiological and kinetic evaluation.

Production, preservation and recovery of sludge with stabilized nitrifying activity over long time can be difficult. Information on the ability of nitrifying sludge to regain its nitrifying activity after long-term storage is still scarce. In this work, the physiological and kinetic changes during the reactivation and stabilization of a nitrifying sludge previously exposed to ampicillin (AMP) were evaluated in a sequential batch reactor (SBR) after its long-term storage (1 year) at 4 °C. After storage, both ammonium and nitrite oxidizing processes were slow, being nitrite oxidation the most affected step. During the reactivation stage (cycles 1-6), physiological and kinetic activity of the nitrifying sludge improved through the operating cycles, in both its ammonium oxidizing and nitrite oxidizing processes. At the end of the reactivation stage, complete nitrifying activity was achieved in 10 h, reaching ammonium consumption efficiencies (ENH4 +) close to 100% and nitrate yields (YNO3 -) of 0.98 mg NO3 --N/mg NH4 +-N consumed without nitrite accumulation. During the stabilization stage (cycles 7-17), results indicated that the sludge could maintain a steady-state respiratory process with restoration percentages of 100% for nitrifying specific rates (qNH4 + and qNO3 -) with respect to their values obtained before storage. Furthermore, during the addition of 15 mg AMP/L (cycles 18-21), the sludge preserved its metabolic capacity to biodegrade 90% of AMP in 2 h. Therefore, long-term storage of nitrifying sludge could be used to preserve nitrifying inocula as bioseeds for bioremediation and bioaugmentation strategies.

Decreased Long-Term Severe Acute Respiratory Syndrome Coronavirus 2-Specific Humoral Immunity in Liver Transplantation Recipients 12 Months After Coronavirus Disease 2019.

Long-term humoral immunity and its protective role in liver transplantation (LT) patients have not been elucidated. We performed a prospective multicenter study to assess the persistence of immunoglobulin G (IgG) antibodies in LT recipients 12 months after coronavirus disease 2019 (COVID-19). A total of 65 LT recipients were matched with 65 nontransplanted patients by a propensity score including variables with recognized impact on COVID-19. LT recipients showed a lower prevalence of anti-nucleocapsid (27.7% versus 49.2%; P = 0.02) and anti-spike IgG antibodies (88.2% versus 100.0%; P = 0.02) at 12 months. Lower index values of anti-nucleocapsid IgG antibodies were also observed in transplantation patients 1 year after COVID-19 (median, 0.49 [interquartile range, 0.15-1.40] versus 1.36 [interquartile range, 0.53-2.91]; P < 0.001). Vaccinated LT recipients showed higher antibody levels compared with unvaccinated patients (P < 0.001); antibody levels reached after vaccination were comparable to those observed in nontransplanted individuals (P = 0.70). In LT patients, a longer interval since transplantation (odds ratio, 1.10; 95% confidence interval, 1.01-1.20) was independently associated with persistence of anti-nucleocapsid IgG antibodies 1 year after infection. In conclusion, compared with nontransplanted patients, LT recipients show a lower long-term persistence of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. However, SARS-CoV-2 vaccination after COVID-19 in LT patients achieves a significant increase in antibody levels, comparable to that of nontransplanted patients.

Changes in humoral immune response after SARS-CoV-2 infection in liver transplant recipients compared to immunocompetent patients.

The protective capacity and duration of humoral immunity after SARS-CoV-2 infection are not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case-control serological data were also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p < .001) and at 6 months (63.4% vs. 90.1%, p < .001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p = .001) and 6 months (p < .001) after COVID-19. In transplant patients, female gender (OR = 13.49, 95% CI: 2.17-83.8), a longer interval since transplantation (OR = 1.19, 95% CI: 1.03-1.36), and therapy with renin-angiotensin-aldosterone system inhibitors (OR = 7.11, 95% CI: 1.47-34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline.

Cometabolic biotransformation of benzotriazole in nitrifying batch cultures.

Benzotriazole (BT) is a corrosion inhibitor widely distributed in aquatic environments. Little is known about the cometabolic capacity of stabilized nitrifying sludge to biotransform BT. The contribution of the nitrification process in the simultaneous oxidation of ammonium and biotransformation of BT (5 mg/L) was evaluated in 49 d batch cultures inoculated with a sludge produced in steady-state nitrification. The nitrifying sludge could consume BT in the obligate presence of ammonium. A higher cometabolic biotransformation capacity was obtained by increasing the initial ammonium concentration (100-300 mg N/L), reaching 2.3- and 5.8-fold increases for efficiency and specific rate of BT removal. At 300 mg NH4+-N/L, the sludge biotransform 40.8% of BT and 77.6% of ammonium which was completely oxidized into nitrate. In assays with allylthiourea added as specific inhibitor of ammonium monooxygenase (AMO), it was shown that the totality of BT cometabolic biotransformation was associated with the AMO activity. The addition of acetate did not favor heterotrophic biotransformation of BT. BT provoked inhibitory effects on nitrification. This is the first study showing the role of ammonium oxidizing bacteria in the cometabolic biotransformation of BT and their potential use for cometabolism application in treatment of wastewater contaminated with ammonium and BT.

Physiological stabilization, community characterization, and nitrogen degradation dynamics in an anammox consortium from estuarine sediments.

Anammox is a cost-effective and sustainable process for nitrogen removal; however, the production of a physiologically stable inoculum is a critical point in the start-up process. In this work, estuarine sediments were used as incubation seeds to obtain cultures with stable anammox activity. Assays were performed in batch cultures fed with stoichiometric amounts of ammonium and nitrite, analyzing physiological response variables and the microbial community. Estuarine sediments showed a stable anammox process after 90 days, consuming ammonium and nitrite simultaneously with concomitant generation of N2 and nitrate in stoichiometric amounts. In kinetic assays, substrates were fully consumed after 210 hr, exhibiting N2 and nitrate yields of 0.85 and 0.10, respectively. The microbial community analysis using PCR-DGGE indicated the presence of uncultured anammox bacteria and members of the genus Candidatus Jettenia. The results evidenced the achievement of anammox cultures, although their start-up and kinetic characteristics were less favorable than those recorded in man-made systems. PRACTITIONER POINTS: Estuarine sediments were used as incubation seeds to obtain cultures with stable anammox activity. The sediments were fed with stoichiometric amounts of ammonium and nitrite, analyzing the physiological response variables and the microbial community. Sediments showed a stable anammox process after 90 days, converting the substrates into N2 and nitrate according to stoichiometry. Anammox cultures were achieved although their start-up and kinetic characteristics were less favorable than those recorded in man-made systems. Microbial community analysis using PCR-DGGE indicated the presence of uncultured anaerobic ammonia-oxidizing bacterium and members of genus Candidatus Jettenia.

H2S oxidation coupled to nitrate reduction in a two-stage bioreactor: Targeting H2S-rich biogas desulfurization.

A two-stage bioreactor operated under anoxic denitrifying conditions was evaluated for desulfurization of synthetic biogas laden with H2S concentrations between 2500 and 10,000 ppmv. H2S removal efficiencies higher than 95% were achieved for H2S loads ranging from 16.2 to 51.9 gS mliquid-3h-1. Average H2S oxidation performance (fraction of S-SO42- produced per gram of S-H2S absorbed) ranged between 8.2 ± 1.2 and 18.7 ± 5.3% under continuous liquid operation. Nitrogen mass balance showed that only 2-6% of the N-NO3- consumed was directed to biomass growth and the rest was directed to denitrification. Significant changes in the bacterial community composition did not hinder the H2S removal efficiency. The bioreactor configuration proposed avoided clogging issues due to elemental sulfur accumulation as commonly occurs in packed bed bioreactors devoted to H2S-rich biogas desulfurization.

Biological ammonium and sulfide oxidation in a nitrifying sequencing batch reactor: Kinetic and microbial population dynamics assessments.

A kinetic study was carried out in a sequencing batch reactor (SBR) (125 mg NH4+-N/L) inoculated with a physiologically stable nitrifying sludge not previously acclimated to sulfur compounds and fed at different initial sulfide concentrations (2.5-20.0 mg HS--S/L). Up to 10.0 mg HS--S/L, the nitrifying process kept stable and complete, reaching an ammonium consumption efficiency (ENH4+) of 100% and a nitrate yield (YNO3-) of 0.95 ± 0.03 mg NO3--N/mg NH4+-N consumed. At 15.0 and 20.0 mg HS--S/L, after an initial alteration in the nitrite oxidizing process, the YNO2- was decreasing throughout the cycles and the YNO3- increasing, obtaining in the last cycle at 20.0 mg HS--S/L, an ENH4+ of 100%, a YNO2- of zero, and a YNO3- of 0.80 mg NO3--N/mg NH4+-N consumed. At the end of the period at 20.0 mg HS--S/L, the specific rates of ammonium consumption and nitrate formation were 15 and 55% lower than their respective values in the control period without sulfide addition, showing that the sludge had a better metabolic adaptation for ammonium oxidizing activity than for nitrite oxidizing activity. The sludge acquired a higher sulfide oxidation capacity along the cycles. Bacterial population dynamics assessment indicated that the ammonium oxidizing bacteria (AOB) community was more diverse and stable than the nitrite oxidizing bacteria (NOB) community. The use of consortia with a previously stabilized nitrifying activity in SBR may constitute an alternative for eliminating simultaneously ammonium by nitrification and sulfide by sulfide oxidation and be implemented for the treatment of wastewater with ammonium and sulfide.

Impact of Everolimus-based Immunosuppression on Renal Function in Liver Transplant Recipients.

BACKGROUND: Calcineurin inhibitors have been implicated in acute and chronic kidney disease after liver transplant (LT). Everolimus (EVR) is a mammalian target of rapamycin inhibitor efficacious in preventing acute cellular rejection while preserving renal function among LT recipients. We evaluated the benefits on renal function of EVR immunosuppression in LT recipients. METHODS: We performed a retrospective and observational study in 477 LT recipients in Virgen de las Nieves Hospital from 2002 to 2019 on the use of EVR with tacrolimus minimization or withdrawal in LT recipients with renal dysfunction. The study included 100 patients starting EVR (20.96%); in 66 (66%) the indication was renal dysfunction. The change in renal function was assessed by estimated glomerular filtration rate. Statistical analyses were performed using SPSS 17.0 software (IBM, Munich, Germany). RESULTS: Fifty 8 patients received mycophenolate mofetil (87.8%), and tacrolimus therapy was stopped in 27 patients (40.9%). Induction therapy with basiliximab was administered in 41 patients (62.12%). There was significant difference between estimated glomerular filtration rate at the time of starting EVR and the first month at last follow-up (49.42 mL/min/1.73 m2 vs 75.27 mL/min/1.73 m2; P < .001) and at end of follow-up (24 months) (49.42 mL/min/1.73 m2 vs 64.32 mL/min/1.73 m2; P = .001). The rate of incidence of adverse events was 48.48% (32/66). Seven patients died during follow-up (10.6%), but there were no EVR-related deaths. Eleven patients (16.6%) developed biopsy-proven acute rejection. CONCLUSION: This study showed that EVR is associated with a beneficial effect on glomerular filtration rate in both the short and long term in LT recipients.

Descriptive Analysis of Everolimus Conversion in Liver Transplant Recipients With Malignant Neoplastic Disease.

BACKGROUND: Calcineurin inhibitors are associated with the development of de novo tumors and increased recurrence of hepatocellular carcinoma after liver transplant. It has been suggested that mammalian target of rapamycin inhibitors (everolimus [EVR]) may improve prognosis. We analyzed our experience on the use of EVR in malignant neoplasms in liver transplantation. METHODS: We performed a retrospective descriptive analysis of 477 transplants performed between 2002 and 2019 at Virgen de las Nieves Hospital. A total of 100 patients received EVR; 23 transplants were because of tumor disease (23%), with de novo tumor in 12 patients and hepatocarcinoma in 11. The statistical study was carried out using the statistical program SPSS 17.0 software. RESULTS: The study included 18 male patients (78.3%) and 5 female patients (21.7%) with an average age of 59.67 years. The most common indications of liver transplant have been alcoholic cirrhosis in 39% and hepatitis C virus cirrhosis in 21.7%. De novo tumors were lung neoplasm in 4 patients (33.3%), lymphoma in 2 patients(16.7%), oropharynx in 2 patients (16.7%), skin tumors in 2 patients (16.7%), and a kidney tumor (8.3%) in 1 patient. As for hepatocellular carcinoma, 8 patients met Milan criteria on the explant (61.5%). Tacrolimus was discontinued in all cases. The average onset time of post-transplant EVR was 2231.42 days in the de novo neoplasms and 307.45 days in those receiving transplants because of hepatocellular carcinoma (P = .05). We observed 5 deaths (21.7%). CONCLUSION: Although the beneficial long-term role of EVR in liver transplant recipients with tumor disease is not demonstrated, it is used by most transplant units, both in de novo neoplasms and those receiving transplants because of hepatocellular carcinoma.

Ampicillin biotransformation by a nitrifying consortium.

Ampicillin is a widely used ß-lactam antibiotic that has been detected in various effluents and can alter biological processes used in wastewater treatment such as nitrification. Physiological and kinetic behaviour of a nitrifying consortium in the presence of ampicillin (AMP) (10, 25, and 50 mg/L) was evaluated in batch cultures. Under the experimental conditions (320 ± 8 mg bacterial protein/L, C/N = 2.4, 24 h), the nitrifying behaviour was very similar among the controls without AMP and the assays with antibiotic, as there was no AMP effect on efficiency (ENH4+ = 99.7 ± 4.2%), yields (YNO2- = 0, YNO3- = 1.0 ± 0.1 mg N/mg NH4+-N consumed), neither specific rates of NH4+ oxidation and NO3- formation. Therefore, nitrifying bacteria were insensitive to AMP presence. At all assayed concentrations, after 24 h, 70.5 ± 3.7% of AMP was removed from the cultures through abiotic (16.0-16.5%), biosorption (23.2-47.0%), and biotransformation (10.0-29.8%) processes. With the increase in the initial AMP concentration, a greater participation of the biotransformation process, associated to an increase in the specific AMP consumption rate was attained. The sludge was able to completely oxidize NH4+ to NO3- by nitrification and eliminate AMP biologically, but without reaching its full mineralization.

Physiologic impact of 2-chlorophenol on denitrification process in mixture with different electron sources.

The aim of this study was to evaluate the physiologic behavior of sludge in the absence and presence of 2-chlorophenol (2-CP) with different electron donors (phenol, glucose, and acetate) during denitrification process. In batch assays with phenol in the presence of 2-CP, a significant decrease of phenol consumption efficiencies (E phenol) up to 99% was observed regarding the cultures without 2-CP. However, in most of the cases, nitrate consumption efficiencies ( E NO 3 - ), and yields of nitrogen gas ( Y N 2 ) and bicarbonate ( Y HCO 3 - ) were high, showing that the denitrifying respiratory process successfully occurred with phenol and 2-CP. The specific consumption rates of nitrate ( q NO 3 - ) and phenol (q phenol) decreased up to 6.0 and 32.3 times, respectively. In assays with glucose in the presence of 2-CP, the denitrifying performance was not significantly altered in terms of efficiencies and product yields; however, q NO 3 - was up to 1.6 times smaller than that obtained without 2-CP whereas q glucose was increased up to 1.17 times. In assays with acetate plus 2-CP, the E NO 3 - , E acetate, and Y N 2 values remained high but 2-CP caused a decrease in Y HCO 3 - . Moreover, q NO 3 - and q acetate increased up to 1.4 and 2.0 times, respectively. These results show that the negative or positive effects of 2-CP on denitrification process depend on the type and concentration of electron source. The obtained physiologic and kinetic information might be useful to define strategies to maintain successful denitrification processes in wastewater treatment bioreactors fed with 2-CP.

Decrease of inhibitory effect of 2-chlorophenol on nitrification in sequencing batch reactors.

The metabolic and kinetic behaviour of a nitrification process in the presence of 2-chlorophenol (2-CP) was evaluated in two sequencing batch reactors (SBR1, SBR2) inoculated with nitrifying sludge previously exposed to phenolic compounds. The SBR1 was inoculated with sludge previously exposed to 2-CP, while the SBR2 was inoculated with sludge previously exposed to p-cresol. An inhibitory effect of 20 mg 2-CP-C/L on both nitrification processes was observed, as specific rates decreased according to a control assay in the absence of 2-CP. However, the inhibitory effect decreased throughout the cycles. At the end of cycle 6, a stable nitrifying process was observed with the sludge previously exposed to 2-CP (SBR1), as an ammonium consumption efficiency and a nitrate production yield close to 99.6 ± 0.3% and 0.99 ± 0.02 were respectively achieved. Despite a complete ammonium consumption being achieved with the sludge previously exposed to p-cresol (SBR2), partial nitrification was observed as nitrate production yield accounted for 0.28 ± 0.08 and nitrite was accumulated within the culture. Nevertheless, both nitrifying sludges had the ability to completely consume 2-CP. The use of SBR systems with nitrifying sludge previously exposed to 2-CP resulted in a better nitrification performance, thus it may be a good alternative for achieving a stable nitrifying respiratory process where complete and simultaneous ammonium and 2-CP consumption can be acquired.

2-Chlorophenol consumption by cometabolism in nitrifying SBR reactors.

Cometabolic consumption of 2-chlorophenol (2-CP) by a nitrifying sludge was evaluated in two SBR reactors fed with 60 mg 2-CP-C/L and different initial ammonium concentrations (100, 200, 300, 400, and 500 mg NH4+-N/L). Irrespectively to the increase in ammonium concentration and throughout the operational cycles, the sludge achieved a complete nitrification in 14 days, accounting for ammonium consumption efficiencies close to 99% and nitrate production yields between 0.93 and 0.99. The sludge was able to completely consume 2-CP within 7 days. The increase in ammonium concentration provoked an increment in the specific rates of both ammonium (qNH4+-N) and 2-CP (q2-CP-C) consumption up to 5.2 and 3.1 times, respectively. The cometabolic effect of the increase in ammonium concentration on 2-CP consumption was supported by a direct and significant relationship between the qNH4+-N and q2-CP-C (r = 0.83). Moreover, batch assays conducted with ammonium, 2-CP, allylthiourea as specific inhibitor of the ammonium monooxygenase (AMO) enzyme, and the sludge inoculated into the reactors, resulted in a decrease of 34% in q2-CP-C, evidencing the participation of the AMO in the consumption of 2-CP. When the same assays were carried out with the sludge obtained from the SBR reactors after 13 operating cycles, a higher participation of the AMO in 2-CP consumption was noticed with a decrease of 53% in q2-CP-C. According to these results, the use of nitrifying sludge and high ammonium concentrations in SBR systems can be a suitable alternative for increasing the cometabolic consumption of recalcitrant compounds like 2-CP.

Serum zinc and copper concentrations and ratios in cirrhotic patients: correlation with severity index.

INTRODUCTION: zinc (Zn) and copper (Cu) are essential elements that play an important role in the whole-body metabolism and seems to have a role in the pathogenesis of the liver cirrhosis (LC). OBJECTIVE: the aim of this study is to evaluate the influence on serum Zn and Cu concentrations and Cu/Zn ratios of different factors like cirrhosis, severity index, age, sex, death, and disease complications. METHODS: ninety-three patients with LC were included. The severity index was measured by the Child-Pugh index (CPI). RESULTS: mean serum Cu concentration and Cu/Zn ratio were significantly higher in patients than in healthy controls (p ≤ 0.001). Serum Zn concentrations were reduced with higher cirrhosis severity (specifically low vsmedium severity CPI, p < 0.05). Mean serum Cu concentration was significantly higher in the oldest (> 50 years) versusyoungest (< 30 years) age group. Serum Zn concentrations were lower and Cu/Zn ratios were higher (p < 0.05) in patients that died. Among complications, significantly higher serum Zn concentrations were found in cirrhotic patients with ascites than in those with bacteremia-sepsis. CONCLUSIONS: levels of Zn, Cu and Cu/Zn ratio are affected by the presence of hepatic cirrhosis. Serum Zn concentrations are lower with higher severity of cirrhosis, while those for Cu are increased in cirrhotic patients. We can observe that the presence of elevated Cu/Zn ratios in these patients might be useful in the evaluation of suspected liver cirrhosis.

Serum zinc and copper concentrations and ratios in cirrhotic patients: correlation with severity index / Concentraciones séricas de zinc, cobre y sus cocientes correspondientes en pacientes cirróticos: correlación con el índice de severidad

Introduction: zinc (Zn) and copper (Cu) are essential elements that play an important role in the whole-body metabolism and seems to have a role in the pathogenesis of the liver cirrhosis (LC).Objective: the aim of this study is to evaluate the influence on serum Zn and Cu concentrations and Cu/Zn ratios of different factors like cirrhosis, severity index, age, sex, death, and disease complications. Methods: ninety-three patients with LC were included. The severity index was measured by the Child-Pugh index (CPI).Results: mean serum Cu concentration and Cu/Zn ratio were significantly higher in patients than in healthy controls (p ≤ 0.001). Serum Zn concentrations were reduced with higher cirrhosis severity (specifically low vsmedium severity CPI, p < 0.05). Mean serum Cu concentration was significantly higher in the oldest (> 50 years) versusyoungest (< 30 years) age group. Serum Zn concentrations were lower and Cu/Zn ratios were higher (p < 0.05) in patients that died. Among complications, significantly higher serum Zn concentrations were found in cirrhotic patients with ascites than in those with bacteremia-sepsis. Conclusions: levels of Zn, Cu and Cu/Zn ratio are affected by the presence of hepatic cirrhosis. Serum Zn concentrations are lower with higher severity of cirrhosis, while those for Cu are increased in cirrhotic patients. We can observe that the presence of elevated Cu/Zn ratios in these patients might be useful in the evaluation of suspected liver cirrhosis

Introducción: el zinc (Zn) y el cobre (Cu) son elementos esenciales ya que juegan un papel fundamental en el metabolismo en general y parecen tener implicación en la patogénesis de la cirrosis hepática (CH). Objetivos: el objetivo del presente estudio es evaluar la influencia sobre los niveles séricos de Zn y Cu, y sobre los cocientes entre los niveles de Cu y Zn de diferentes factores como la cirrosis, el índice de severidad, la edad, el sexo, la mortalidad y las complicaciones de la enfermedad. Metodología: noventa y tres pacientes con CH fueron incluidos en el estudio y el grado de severidad se midió utilizando el índice Child-Pugh (ICP). Resultados: las concentraciones séricas de Cu y los cocientes entre los niveles de Cu y Zn se encontraron significativamente aumentados en los pacientes con respecto a los controles sanos (p ≤ 0.001). A mayor grado de severidad cirrótica, se obtuvieron valores medios de Zn significativamente disminuidos (concretamente en los enfermos con ICP bajo frente a los que tenían un ICP medio, p < 0.05). La media de las concentraciones séricas de Cu fue significativamente superior en el grupo de sujetos de mayor edad (> 50 años) con respecto al grupo más joven (< 30 años). En aquellos pacientes que habían sufrido un deceso, las concentraciones séricas de Zn estaban significativamente disminuidas, mientras que los cocientes entre los niveles de Cu y Zn se encontraron elevadas (p < 0.05). En cuanto a las complicaciones de la enfermedad, obtuvimos valores séricos significativamente elevados de Zn en aquellos pacientes cirróticos que padecían ascitis respecto a los que presentaban bacteriemia-sepsis. Conclusiones: los valores de Zn, Cu y los cocientes entre los niveles de Cu y Zn se encuentran afectados en la enfermedad cirrótica. Las concentraciones séricas de Zn son bajas cuando existe un mayor grado de severidad de la cirrosis hepática, mientras que los valores de Cu apararen incrementados en los pacientes con esta enfermedad. Podemos observar que la presencia de valores elevados de los cocientes entre los niveles de Cu y Zn podría ser de utilidad en la evaluación de la posible presencia de la enfermedad

Transgene flow in Mexican maize revisited: Socio-biological analysis across two contrasting farmer communities and seed management systems.

The flow of transgenes into landraces and wild relatives is an important biosafety concern. The case of transgene flow into local maize varieties in Mexico (the center of origin of maize) has been intensively debated over the past 15 years, including legal, political, and environmental disputes fanned by the existence of a significant scientific controversy over the methods used for the detection of transgenes. The use of diverse approaches and a lack of harmonized methods specific to the detection and monitoring of transgenes in landraces have generated both positive and negative results regarding contamination of Mexican maize with genetically modified material over the years. In this paper, we revisit the case of transgene contamination in Mexican maize and present a novel research approach based on socio-biological analysis of contrasting communities and seed management systems. Two communities were used to investigate how different social and biological factors can affect transgene flow and impact transgene spread in Mexico. Our results show the presence of transgenes in one community and thus support the position that transgenes are highly likely to be present in Mexican maize landraces. However, our work also demonstrates that the extent and frequency with which transgenes can be found will significantly depend on the societal characteristics and seed management systems of the local communities. Therefore, we argue that future analysis of transgene presence should include social research on the seed management practices in the sampling area so that more robust and comprehensive understandings and conclusions can be drawn.

Ampicillin Mineralization by Denitrifying Process: Kinetic and Metabolic Effects.

The impact of the antibiotic ampicillin (AMP) on the metabolic and kinetics of denitrification process as well as the sludge ability for oxidizing it was evaluated in batch assays. Denitrifying reference assays with acetate-C and nitrate-N (C/N ratio of 1.1) were conducted for establishing the metabolic and kinetic performance of the denitrifying sludge. Assays amended with 10 mg AMP-C L-1 were also performed. In reference assays, acetate and nitrate consumption efficiencies of 100% with a total conversion to HCO3- and N2 were achieved within 1.5 h. When 10 mg AMP-C L-1 was added, total and simultaneous consumption of nitrate-N, acetate-C, and AMP-C was achieved within 12 h. The substrates were completely reduced to N2 and oxidized to HCO3-, respectively. No nitrite-N was registered at the end of culture. AMP caused a reversible inhibitory effect on specific nitrate and acetate consumption and N2 production rates. Complete consumption and mineralization of AMP associated to nitrate reduction to N2 were achieved. This work provides the first evidences on the metabolic and kinetic performance of a denitrifying sludge exposed to AMP. These results might be considered for proposing useful wastewater treatments where ß-Lactam antibiotics can be present.

Simultaneous oxidation of ammonium and cresol isomers in a sequencing batch reactor: physiological and kinetic study.

The aim of this study was to evaluate the physiological and kinetic capacities of a nitrifying consortium to simultaneously oxidize ammonium (138 mg N/L day), m-cresol, o-cresol, and p-cresol (180 mg C/L day in mixture) in a sequencing batch reactor (SBR). A 1-L SBR was firstly operated without cresol addition (phase I) for stabilizing the nitrification respiratory process with ammonium consumption efficiencies close to 100 % and obtaining nitrate as the main end product. When cresols were added (phase II m-cresol (10, 20, and 30 mg C/L); phase III m-cresol (30 mg C/L) and o-cresol (10, 20, and 30 mg C/L); phase IV a mixture of three isomers (30 mg C/L each one)), inhibitory effects were evidenced by decreased values of the specific rates of nitrification compared with values from phase I. However, the inhibition diminished throughout the operation cycles, and the overall nitrifying physiological activity of the sludge was not altered in terms of efficiency and nitrate yield. The different cresols were totally consumed, being o-cresol the most recalcitrant. The use of SBR allowed a metabolic adaptation of the consortium to oxidize the cresols as the specific rates of consumption increased throughout the cycles, showing that this type of reactor can be a good alternative for treating industrial effluents in a unique reactor.