Microbial Interactions between Amylolytic and Non-Amylolytic Lactic Acid Bacteria Strains Isolated during the Fermentation of Pozol.

Pozol is a Mexican beverage prepared from fermented nixtamalized maize dough. To contribute to understanding its complex microbial ecology, the effect of inoculating on MRS-starch pure and mixed cultures of amylolytic Sii-25124 and non-amylolytic W. confusa 17, isolated from pozol, were studied on their interactions and fermentation parameters. These were compared with L. plantarum A6, an amylolytic strain isolated from cassava. Microbial growth, kinetic parameters, amylolytic activity, lactic acid production, and hydrolysis products from starch fermentation were measured. The population dynamics were followed by qPCR. L. plantarum A6 showed higher enzymatic activity, lactic acid, biomass production, and kinetic parameters than pozol LAB in pure cultures. Mixed culture of each pozol LAB with L. plantarum A6 showed a significant decrease in amylolytic activity, lactic acid yield, specific growth rate, and specific rate of amylase production. The interaction between Sii-25124 and W. confusa 17 increased the global maximum specific growth rate (µ), the lactic acid yield from starch (Ylac/s), lactic acid yield from biomass (Ylac/x), and specific rate of lactic acid production (qlac) by 15, 30, 30, and 40%, respectively, compared with the pure culture of Sii-25124. Interactions between the two strains are essential for this fermentation.

Validation of aqueous two-phase extraction method.

Nowadays, consumer interest in food with natural ingredients has increased. This need has led to the research of new sources and green extraction methods. Betalains are compounds responsible for giving color to cacti fruits. The aim is to obtain low-sugar betacyanins extracts from jiotilla Escontria chiotilla using aqueous two-phase systems (ATPS) to color food with the extract. The effect of principal parameters of ATPS (Ethyl alcohol- KH2PO4/K2HPO4) as tie-line length (TL;40,50 and 70), phase volume ratios (Vr; 1 and 3) on the partitioning of betacyanins, betaxanthins, total sugars, reducing sugars, and antioxidant activity in the extract was evaluated. The yields were determined from the top and bottom phases of the aforementioned parameters. Multivariate analysis of variance (MANOVA, α = 0.05) showed that TLL and Vr were statistically significant (P < 0.05). The lowest bottom sugar yield (25.78 ± 3.14%) corresponds to TLL = 40, Vr = 3. Under these conditions, the corresponding value for betacyanins yield is 62.98±4.52%. For the first time, the ATPS was used to extract betacyanins from cactus fruit.•Escontria chiotilla, as a biological source, contained a high percent of betalains•Aqueous two-phase systems (ATPS) was statistically optimized•The developed method enriches the valorization of environmentally related plants waste materials.

Adding Far-Red to Red-Blue Light-Emitting Diode Light Promotes Yield of Lettuce at Different Planting Densities.

The economic viability and energy use of vertical farms strongly depend on the efficiency of the use of light. Increasing far-red radiation (FR, 700-800 nm) relative to photosynthetically active radiation (PAR, 400-700 nm) may induce shade avoidance responses including stem elongation and leaf expansion, which would benefit light interception, and FR might even be photosynthetically active when used in combination with PAR. The aims of this study are to investigate the interaction between FR and planting density and to quantify the underlying components of the FR effects on growth. Lettuce (Lactuca sativa cv. Expertise RZ) was grown in a climate chamber under two FR treatments (0 or 52 µmol m-2 s-1) and three planting densities (23, 37, and 51 plants m-2). PAR of 89% red and 11% blue was kept at 218 µmol m-2 s-1. Adding FR increased plant dry weight after 4 weeks by 46-77% (largest effect at lowest planting density) and leaf area by 58-75% (largest effect at middle planting density). Radiation use efficiency (RUE: plant dry weight per unit of incident radiation, 400-800 nm) increased by 17-42% and incident light use efficiency (LUEinc: plant dry weight per unit of incident PAR, 400-700 nm) increased by 46-77% by adding FR; the largest FR effects were observed at the lowest planting density. Intercepted light use efficiency (LUEint: plant dry weight per unit of intercepted PAR) increased by adding FR (8-23%). Neither specific leaf area nor net leaf photosynthetic rate was influenced by FR. We conclude that supplemental FR increased plant biomass production mainly by faster leaf area expansion, which increased light interception. The effects of FR on plant dry weight are stronger at low than at high planting density. Additionally, an increased LUEint may contribute to the increased biomass production.

Mezcal: indigenous Saccharomyces cerevisiae strains and their potential as starter cultures.

In this study, 19 indigenous mezcal Saccharomyces cerevisiae strains were screened for their tolerance to grow under different stress conditions and their potential use in fermentation. All strains were able to tolerate pH value of 3, significant levels of glucose (30%), ethanol (12% v/v), and temperature of 37 °C. Eleven of them were able to grow in presence of 15% of ethanol, but only CH7 and PA18 strains grew at 42 °C. Both were selected for evaluation of their fermentative abilities in maguey juice and in a synthetic medium incubated at 30 and 40 °C. Temperature of 40 °C had a positive effect on the ethanol production, increasing the productivity and efficiency in maguey fermentation. Ethyl acetate, isobutanol and isoamyl alcohols production was favored at 30 °C. Both evaluated strains presented a good fermentative capacity and production of volatile compounds, suggesting their potential use as starter cultures in mezcal fermentation.

Predominant Yeasts During Artisanal Mezcal Fermentation and Their Capacity to Ferment Maguey Juice.

Artisanal mezcal is produced by the natural fermentation of maguey juice, which frequently results in a process that becomes stuck or is sluggish. Using selected indigenous starter inoculums of Saccharomyces and non-Saccharomyces yeasts is considered beneficial in overcoming these problems and thereby preserving the essence of the artisanal process. In this work, three hundred and four yeast isolates were recovered from 17 distilleries and then grouped by the ARDRA analysis, their restriction profiles were clustered in 15 groups. Four of them included 90% of all isolates, and these were identified using the sequence of the D1/D2 domain of the large-subunit rDNA. Pichia kudriavzevii, Pichia manshurica, Saccharomyces cerevisiae, and Kluyveromyces marxianus were detected as predominant species. Both species belonging to the Pichia genus were detected in 88% of the distilleries, followed by S. cerevisiae (70%) and K. marxianus (50%). In order to evaluate the fermentative capacity, one strain of each species was assessed in a pure and mixed culture in two culture media, filtered maguey juice (MJ) and maguey juice including its bagasse (MJB). Findings demonstrated that non-Saccharomyces yeast presented better growth than that of S. cerevisiae. K. marxianus PA16 was more efficient for ethanol production than S. cerevisiae DI14. It produced 32 g/L of ethanol with a yield of 0.47 g/g and efficient of 90%. While, P. kudriavzevii produced more ethyl acetate (280 mg/L) than the others species. All fermentations were characterized by the presence of isobutyl and isoamyl alcohol. The presence of K. marxianus in a mixed culture, improved the ethanol production and volatile compounds increased using co-cultures.

Cardiovascular morbidity and mortality after liver transplantation: The protective role of mycophenolate mofetil.

Cardiovascular (CV) diseases are recognized longterm causes of death after liver transplantation (LT). The objective of this multicenter study was to analyze the prevalence and the evolution of CV risk factors and CV morbidity and mortality in 1819 LT recipients along 5 years after LT. The influence of baseline variables on survival, morbidity, and mortality was studied. There was a continuous and significant increase of the prevalence of all the CV risk factors (except smoking) after LT. CV diseases were the fourth cause of mortality in the 5 years after LT, causing 12% of deaths during the follow-up. Most CV events (39%) occurred in the first year after LT. Preexisting CV risk factors such as age, pre-LT CV events, diabetes, metabolic syndrome, and hyperuricemia, and mycophenolate-free immunosuppressive therapy, increased post-LT CV morbidity and mortality. The development of new-onset CV risk factors after LT, such as dyslipidemia and obesity, independently affected late CV morbidity and mortality. Tacrolimus and steroids increased the risk of posttransplant diabetes, whereas cyclosporine increased the risk of arterial hypertension, dyslipidemia, and metabolic syndrome. In conclusion, CV complications and CV mortality are frequent in LT recipients. Preexisting CV risk factors, immunosuppressive drugs, but also the early new onset of obesity and dyslipidemia after LT play an important role on late CV complications. A strict metabolic control in the immediate post-LT period is advisable for improving CV risk of LT recipients. Liver Transplantation 23 498-509 2017 AASLD.

Approach to an obstetric prognosis scale: The modified SOFA scale.

BACKGROUND: Severe obstetric morbidity constitutes a serious problem worldwide; however, an effective obstetrical prognosis scale is still missing. OBJECTIVE: To propose a modified Sequential Organ Failure Assessment Score (SOFA) score based on time before reaching specialized medical attention. METHOD: This was an ambispective, descriptive study, including all women treated at the Obstetrical Intensive Care Unit (OICU) of the "Mónica Pretelini Sáenz" Maternal-Perinatal Hospital (HMPMPS), Toluca, Mexico, from June 2009 to June 2013. The patient's SOFA score and clinical evolution were registered daily. A modified obstetrical SOFA scale was constructed adjusting the value of 180 instead of 200 in the punctuation column of 3 for the PaO2/FiO2 ratio and adding a file of disease evolution time with sepsis prior to reaching specialized medical attention. RESULTS: Two hundred thirty two patients, with an average age (SD) of 26.42 (±7.54) years, mean gestational age of 33 (±7.5) weeks were included in the study; 118 suffered from pre-eclampsia, 56 obstetric haemorrhages, 41 eclampsia (25 preceded by pre-eclampsia) and 23, sepsis. ROC curves showed a higher area under the curve (AUC) for the modified SOFA (0.868; p<0.001) than SOFA (0.796; p=0.003), in the prediction of maternal mortality. CONCLUSIONS: The SOFA score, taking into account a lower value for the Kirby index and a threshold time of 12-h with sepsis before getting specialized medical attention, shows a good predictive value for maternal death and could be considered for evaluating the severity of complicated obstetrical patients. FUNDING: None declared.

Favorable longterm outcomes of liver transplant recipients treated de novo with once-daily tacrolimus: Results of a single-center cohort.

The once-daily prolonged-release formulation of tacrolimus has been recently related with significant graft and patient mid-term survival advantages; however, practical information on the de novo administration after liver transplantation and longterm outcomes is currently lacking. This study is a 5-year retrospective analysis of a single-center cohort of liver transplant recipients treated de novo with once-daily tacrolimus (April 2008/August 2011). The study cohort consisted of 160 patients, including 23 with pretransplant renal dysfunction, with a median follow-up of 57.6 months (interquartile range, 46.6-69.0). Tacrolimus target trough levels were 5-10 ng/mL during the first 3 months after transplant, reducing progressively to <7 ng/mL after the first posttransplant year. Once-daily tacrolimus was withdrawn in 35 (21.8%) patients during follow-up, mostly due to renal dysfunction and/or metabolic syndrome. The biopsy-proven acute rejection rate was 12.5% with no cases of steroid-resistant rejection. The cumulative incidence of de novo diabetes, hypertension, and dyslipidemia were 16.9%, 31.2%, and 6.5%, respectively. Hepatocellular carcinoma recurrence rate was 2.8%. Renal function remained stable after the sixth month after transplant with a mean estimated glomerular filtration rate of 77.7 ± 19.6 mL/minute/1.73 m(2) at 5 years. None of our patients developed chronic kidney disease stage 4 or 5. Patient survival at 1, 3, and 5 years was 96.3%, 91.9%, and 88.3%, respectively. Overall survival of patients with Model for End-Stage Liver Disease (MELD) score > 25 points was not significantly different. In conclusion, our study suggests that immunosuppression based on de novo once-daily tacrolimus is feasible in routine clinical practice, showing favorable outcomes and outstanding longterm survival even in patients with high MELD scores. Liver Transplantation 22 1391-1400 2016 AASLD.

Liver transplantation for adenomatosis: European experience.

The aim of this study was to collect data from patients who underwent liver transplantation (LT) for adenomatosis; to analyze the symptoms, the characteristics of the disease, and the recipient outcomes; and to better define the role of LT in this rare indication. This retrospective multicenter study, based on data from the European Liver Transplant Registry, encompassed patients who underwent LT for adenomatosis between January 1, 1986, and July 15, 2013, in Europe. Patients with glycogen storage disease (GSD) type IA were not excluded. This study included 49 patients. Sixteen patients had GSD, and 7 had liver vascular abnormalities. The main indications for transplantation were either a suspicion of hepatocellular carcinoma (HCC; 15 patients) or a histologically proven HCC (16 patients), but only 17 had actual malignant transformation (MT) of adenomas. GSD status was similar for the 2 groups, except for age and the presence of HCC on explants (P = 0.030). Three patients with HCC on explant developed recurrence after transplantation. We obtained and studied the pathomolecular characteristics for 23 patients. In conclusion, LT should remain an extremely rare treatment for adenomatosis. Indications for transplantation primarily concern the MT of adenomas. The decision should rely on morphological data and histological evidence of MT. Additional indications should be discussed on a case-by-case basis. In this report, we propose a simplified approach to this decision-making process.

Use of artificial intelligence as an innovative donor-recipient matching model for liver transplantation: results from a multicenter Spanish study.

BACKGROUND & AIMS: There is an increasing discrepancy between the number of potential liver graft recipients and the number of organs available. Organ allocation should follow the concept of benefit of survival, avoiding human-innate subjectivity. The aim of this study is to use artificial-neural-networks (ANNs) for donor-recipient (D-R) matching in liver transplantation (LT) and to compare its accuracy with validated scores (MELD, D-MELD, DRI, P-SOFT, SOFT, and BAR) of graft survival. METHODS: 64 donor and recipient variables from a set of 1003 LTs from a multicenter study including 11 Spanish centres were included. For each D-R pair, common statistics (simple and multiple regression models) and ANN formulae for two non-complementary probability-models of 3-month graft-survival and -loss were calculated: a positive-survival (NN-CCR) and a negative-loss (NN-MS) model. The NN models were obtained by using the Neural Net Evolutionary Programming (NNEP) algorithm. Additionally, receiver-operating-curves (ROC) were performed to validate ANNs against other scores. RESULTS: Optimal results for NN-CCR and NN-MS models were obtained, with the best performance in predicting the probability of graft-survival (90.79%) and -loss (71.42%) for each D-R pair, significantly improving results from multiple regressions. ROC curves for 3-months graft-survival and -loss predictions were significantly more accurate for ANN than for other scores in both NN-CCR (AUROC-ANN=0.80 vs. -MELD=0.50; -D-MELD=0.54; -P-SOFT=0.54; -SOFT=0.55; -BAR=0.67 and -DRI=0.42) and NN-MS (AUROC-ANN=0.82 vs. -MELD=0.41; -D-MELD=0.47; -P-SOFT=0.43; -SOFT=0.57, -BAR=0.61 and -DRI=0.48). CONCLUSIONS: ANNs may be considered a powerful decision-making technology for this dataset, optimizing the principles of justice, efficiency and equity. This may be a useful tool for predicting the 3-month outcome and a potential research area for future D-R matching models.

Grado de homogeneidad de los grupos españoles de trasplante hepático en el tratamiento del hepatocarcinoma / Degree of uniformity in the treatment of hepatocellular carcinoma in the Spanish teams of liver transplantation

No disponible

Tacrolimus dose individualization in "de novo" patients after 10 years of experience in liver transplantation: pharmacokinetic considerations and patient pathophysiology.

AIM: To determine how changes in tacrolimus (TAC) immunosuppression clinical practice, in the first 15 days post liver transplantation (LT) and across a decade, impact a clinical covariate - pharmacokinetic (PK) model, developed in data from 1998, thus testing its utility in dose individualization across time. Patient cohorts from 1998 (Reference: R-1998) and 2007 (EVALUATION: E-2007) were compared. METHODS: Analysis of monitoring observations (Cmin and Cmin/dose) and the biochemical variables aspartate aminotransferase (AST), hematocrit (HCT), albumin (ALB) and serum creatinine (SCr) was done for 0 - 3 and 4 - 15 days post transplantation (PT). The population PK model developed for R-1998 [1] was re-evaluated for the two cohorts. RESULTS: Significant differences in R-1998 vs. E-2007 existed in Cmin and Cmin/dose and in covariates AST (as hepatic function marker) and SCr (as toxicity marker). E-2007 had lower levels of Cmin and Cmin/dose (1/CL), lower AST with faster recovery and lower variability in Cmin/dose for similar dose. AST was a covariate on CL/F in the 0 - 3 day PT period. In 4 - 15 days PT for E-2007, low levels of HCT and ALB as CL/F predictors confirmed a subgroup with higher CL/F (23.8 l/h vs. 19.3 l/h). The R-1998 model's original structure was confirmed. CONCLUSIONS: Ten years of use of TAC shows gain in therapeutic targeting efficiency, due to improvement in LT methods, knowledge of the drug and consideration of PK steady state. The remaining uncertainty with TAC monitoring in LT can be resolved with application of PK principles combined with patients' diosyncrasies in the model developed for TAC dose individualization in R-1998. The applicability of the model as nucleus in Bayes individualization remains intact across a decade.

Liver transplantation for neuroendocrine tumors in Europe-results and trends in patient selection: a 213-case European liver transplant registry study.

OBJECTIVE: The purpose of this study was to assess outcomes and indications in a large cohort of patients who underwent liver transplantation (LT) for liver metastases (LM) from neuroendocrine tumors (NET) over a 27-year period. BACKGROUND: LT for NET remains controversial due to the absence of clear selection criteria and the scarcity and heterogeneity of reported cases. METHODS: This retrospective multicentric study included 213 patients who underwent LT for NET performed in 35 centers in 11 European countries between 1982 and 2009. One hundred seven patients underwent transplantation before 2000 and 106 after 2000. Mean age at the time of LT was 46 years. Half of the patients presented hormone secretion and 55% had hepatomegaly. Before LT, 83% of patients had undergone surgical treatment of the primary tumor and/or LM and 76% had received chemotherapy. The median interval between diagnosis of LM and LT was 25 months (range, 1-149 months). In addition to LT, 24 patients underwent major resection procedures and 30 patients underwent minor resection procedures. RESULTS: Three-month postoperative mortality was 10%. At 5 years after LT, overall survival (OS) was 52% and disease-free survival was 30%. At 5 years from diagnosis of LM, OS was 73%. Multivariate analysis identified 3 predictors of poor outcome, that is, major resection in addition to LT, poor tumor differentiation, and hepatomegaly. Since 2000, 5-year OS has increased to 59% in relation with fewer patients presenting poor prognostic factors. Multivariate analysis of the 106 cases treated since 2000 identified the following predictors of poor outcome: hepatomegaly, age more than 45 years, and any amount of resection concurrent with LT. CONCLUSIONS: LT is an effective treatment of unresectable LM from NET. Patient selection based on the aforementioned predictors can achieve a 5-year OS between 60% and 80%. However, use of overly restrictive criteria may deny LT to some patients who could benefit. Optimal timing for LT in patients with stable versus progressive disease remains unclear.

Tacrolimus pharmacokinetics in the early post-liver transplantation period and clinical applicability via Bayesian prediction.

PURPOSE: To define and validate a pharmacokinetic (PK) model for tacrolimus (TAC) that includes patient pathophysiology and has clinical applicability in the first 2 weeks post-liver transplantation (PLT). METHODS: Routine monitoring records [dose, trough levels (C(min)), demographics, biochemistry] from 75 patients treated with TAC (Prograf®) PLT were used to develop a population PK model (employing NONMEM®) testing for predictors of oral clearance (CL/F) according to bedside evidence and primarily with aspartate aminotransferase (AST), albumin (ALB), and hematocrit (HCT). Patients were catergorized into subgroups with above and below "normal" thresholds for AST (500 U/L), ALB (2.5 g/dL), and HCT (28 %), respectively. The model was validated with ten patients from the same period and 15 more recent patients. An empirical Bayes method was developed and applied to the prediction of individual profiles serving as a dose adjustment tool. RESULTS: The number of days PLT (Days PLT) was a key variable during the first 2 weeks, with a dichotomy in the mono-compartmental parameters for 0-3 Days PLT and 4-15 Days PLT. During 0-3 Days PLT, AST levels, indicative of allograft functionality (and TAC metabolism), were crucial predictors of elimination. Three groups were identified with the following clearances: CL/F0₋3 = 8.93 L/h for AST ≥ 500 U/L and CL/F0₋3 = 11.0 L/h for AST <500 U/L. During 4-15 Day PLT, low values of ALB (<2.5 g/dL) and HCT (<28 %) combined were determinant of a patient subgroup with a tendency to underexposure and complexity in empirical dose adjustment. The CL/F4₋15 = 25.1 L/h for this subgroup compared to CL/F4₋15 = 17.1 L/h for the others in that period. The elimination half-life for individual patients varied over tenfold so that a large number of subjects were not at steady state, making the use of a PK model necessary to achieve rapidly and safely the target concentration for TAC in LT. Validation of the model demonstrated that both bias and precision were within acceptable limits. CONCLUSION: For TAC therapy, covariate models using mixed effects methods are most useful when combined with patient-specific biochemical assays as well as clinical evidence. In such cases, the observed C(min) and Bayes methods can provide the most likely individual PK parameters, hence the optimal next dose to reach individualized target levels for each patient.

Venous outflow obstruction after orthotopic liver transplantation: use of a breast implant to maintain graft position.

Hepatic venous outflow obstruction (HVOO) is a rare complication after orthotopic liver transplantation (OLT) usually related to technical issues or to malposition or kinking of the hepatic graft. When HVOO is diagnosed during the early post-transplant period, surgical options are technically very demanding and outcomes discouraging. Therefore, angioplasty and stent placement have been indicated to avoid a chronic lesion of the graft. Three cases of HVOO after OLT are reported. HVOO was diagnosed during the early post-transplant period and was due to graft malposition in two patients and kinking of the vena cava anastomosis in one. All patients were successfully treated with a 300-cc gel-filled breast implant surgically placed in the right hepatic fossa with the liver graft resting on it. Massive ascites in all three patients disappeared and renal impairment resolved within two wk post-implant placement. No prosthesis-related complications have been observed after a follow-up ranging from 30 to 58 months. We describe a simple and effective method of maintaining the liver graft in an adequate position to achieve prolonged relief of the outflow obstruction for the whole graft and discuss the advantages of a breast implant over stent placement or the use of different balloon catheters.