Perioperative and oncologic outcomes of interval colectomy performed by acute care surgeons after stenting as a bridge to surgery for left-sided malignant colonic obstruction are non-inferior to the outcomes of colorectal surgeons in the elective setting: single center experience.

PURPOSE: To analyze if perioperative and oncologic outcomes with stenting as a bridge to surgery (SEMS-BS) and interval colectomy performed by acute care surgeons for left-sided occlusive colonic neoplasms (LSCON) are non-inferior to those obtained by colorectal surgeons for non-occlusive tumors of the same location in the full-elective context. METHODS: From January 2011 to January 2021, patients with LSCON at University Regional Hospital in Málaga (Spain) were directed to a SEMS-BS strategy with an interval colectomy performed by acute care surgeons and included in the study group (SEMS-BS). The control group was formed with patients from the Colorectal Division elective surgical activity dataset, matching by ASA, stage, location and year of surgery on a ratio 1:2. Stages IV or palliative stenting were excluded. Software SPSS 23.0 was used to analyze perioperative and oncologic (defined by overall -OS- and disease free -DFS-survival) outcomes. RESULTS: SEMS-BS and control group included 56 and 98 patients, respectively. In SEMS-BS group, rates of technical/clinical failure and perforation were 5.35% (3/56), 3.57% (2/56) and 3.57% (2/56). Surgery was performed with a median interval time of 11 days (9-16). No differences between groups were observed in perioperative outcomes (laparoscopic approach, primary anastomosis rate, morbidity or mortality). As well, no statistically significant differences were observed in OS and DFS between groups, both compared globally (OS:p < 0.94; DFS:p < 0.67, respectively) or by stages I-II (OS:p < 0.78; DFS:p < 0.17) and III (OS:p < 0.86; DFS:p < 0.70). CONCLUSION: Perioperative and oncologic outcomes of a strategy with SEMS-BS for LSCON are non-inferior to those obtained in the elective setting for non-occlusive neoplasms in the same location. Technical and oncologic safety of interval colectomy performed on a semi-scheduled situation by acute care surgeons is absolutely warranted.

Microalgae community shifts during the biogas upgrading in an alkaline open photobioreactor.

AIMS: To achieve the functional specialization of a microalgae community through operational tuning of an open photobioreactor used for biogas upgrading under alkaline conditions. METHODS AND RESULTS: An open photobioreactor was inoculated with an indigenous microalgae sample from the Texcoco Soda Lake. A microalgae community was adapted to fix CO2 from synthetic biogas through different culture conditions reaching a maximum of 220 mg CO2  l-1 per day. Picochlorum sp. and Scenedesmus sp. were identified as the prominent microalgae genera by molecular fingerprinting (partial sequencing of 16S rRNA and 18S rRNA genes) but only the first was detected by microscopy screening. Changes in the microalgae community profile were monitored by a range-weighted richness index, reaching the lowest value when biogas was upgraded. CONCLUSIONS: A robust microalgae community in the open photobioreactor was obtained after different culture conditions. The specialization of microalgae community for CO2 fixation under H2 S presence was driven by biogas upgrading conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: The alkaline conditions enhance the CO2 absorption from biogas and could optimize specialized microalgae communities in the open photobioreactor. Denaturing gradient gel electrophoresis fingerprinting and richness index comparison are useful methods for the evaluation of microalgae community shifts and photosynthetic activity performance, particularly in systems intended for CO2 removal from biogas where the CO2 assimilation potential can be related to the microbial richness.

Lima de permeabilidad: capacidad de centrado y deformación. Estudio in vitro / Patency File: Centring ability and deformation. An in vitro study

Objetivo. Evaluar el transporte y la capacidad de centrado del foramen mayor, después de utilizar las limas K#10 de acero inoxidable y las limas C-Pilot como limas de permeabilidad. Material y métodos. Se emplearon veintiocho conductos mesiovestibulares de primeros molares mandibulares y maxilares, que fueron divididos en dos grupos de 14 muestras cada uno. Las limas K#10 de acero inoxidable y C-Pilot#10 se utilizaron como instrumentos de permeabilidad en los grupos A y B respectivamente. El foramen mayor fue fotografiado antes y después de realizar la permeabilización de cada conducto. Las imágenes fueron superpuestas con el programa Photoshop y analizadas con el programa Autocad. Los parámetros que se evaluaron fueron la cantidad de transporte, la capacidad de centrado, el área y el perímetro. La capacidad de centrado y el transporte fueron calculados en dos direcciones: dirección de máxima curvatura (MC) y dirección vertical a máxima curvatura (VC). El análisis estadístico se realizó con el test de Anova. Resultados. No encontramos diferencias significativas entre ambos instrumentos en la capacidad de centrado y la cantidad de deformación en cada una de las direcciones evaluadas (MC y VC) (p > 0,05). Encontramos diferencias significativas en el área entre los grupos A y B (p = 0,03) y en el perímetro entre ambos grupos (p = 0,029). Conclusiones. No encontramos diferencias significativas en la cantidad de deformación y la capacidad de centrado de las limas K#10 de acero inoxidable y las limas C-Pilot cuando fueron utilizadas como instrumentos de permeabilidad (AU)

Objective. The aim of this study was to evaluate root canal transportation and centring ability at the major foramen through the use of stainless steel size 10 K-Flex files and size 10 C-pilot files when used as patency files. Matherials and Methods. Twenty-eight mesiobuccal Canals of maxillary and mandibular first molars were divided into two groups of 14 canals each. Size 10 stainless steel K-Flex files and size 10 C-Pilot files were used as patency instruments in groups A and B respectively. The major foramen was photographed before and after instrumentation. The images were superimposed and then evaluated using Adobe Photoshop and Autocad. The parameters evaluated were canal transportation, centring ability perimeter and area. Transportation and centring ability were calculated in two directions: the direction of maximum curvature (MC) and a direction vertical to the maximum curvature (VC). The statistical analysis was perfomed using Anova test. Results. No significant differences were observed amongst the different instruments with respect to centring ability and transportation in either direction (P >0,05). Significant differences were observed in the area between groups A and B (P = 0.03) and in the perimeter between groups A and B (P = 0.029). Conclusions. No statistical differences were found in transportation and centring ability when size 10 K-file and size 10 C-Pilot file were used as patency file (AU)

Liver transplantation without abdominal drainage.

This observational cohort compared 70 consecutive liver transplantations (OLT) with no intra-abdominal drain and 70 control subjects C with an intra-abdominal drain who were operated immediately prior to them. We sought to assess the impact of abdominal drainage on the diagnosis and prevention of early postoperative complications of hemoperitoneum, reinterventions, biliary leaks or percutaneous drainage. We assessed variables related to the recipient (age, indication, pretransplant ascites, body mass index, Model for End-stage Liver Disease score, and rejection episodes, to the donor (age, steatosis and, ischemia time) as well as intra- and postoperative factors (surgery time, blood product use, and coagulopathy). The endpoint was defined as the need for a reintervention, postoperative paracentesis, appearance/drainage of collections, as well as lengths of hospital and intensive care unit (ICU) stays. Postoperative ICU and in-hospital stay were similar between the groups (3.6 versus 3.7 days and 12 versus 14 days respectively). Six patients in the drainage group were reoperated due to hemoperitoneum, whereas it was one in the cohort without drainage. Three patients presented a biliary fistula, two in the group without drainage, and one in the drainage group. One patient in the drainage group required percutaneous drainage of an intra-abdominal collection. The need for postoperative paracentesis was greater among the group without drainage (30% versus 6%; P < .008) and among those with a preoperative ascites > 1000 mL (38%). Patients with drainage displayed a greater incidence of perihepatic hematomas upon ultrasound (50% versus 22%, P < .008) and required more postoperative blood products, especially plasma (P < .01). In conclusion, OLT without intra- abdominal drainage is safe and does not increase morbidity. It seems likely that drainage may be responsible for intra-abdominal hematomas and greater consumption of blood products.

Impact of blood amylase peak over vascular graft thrombosis in pancreas transplantation.

BACKGROUND: Vascular graft thrombosis (VGT) is still the achuilles heel in pancreas transplantation (PT); it is the main cause of nonimmunologic graft loss. Early diagnosis is essential to avoid transplantectomy. The aim of our study was to analyze the peak amylase during the first 3 days after PT as risk factor for VGT. METHODS: This retrospective study included 58 pancreas transplants in 55 patients from January 2007 to November 2011. They underwent an anticoagulation protocol based on unfractionated heparin and low-molecular-weight heparin. The technique consisted of enteric drainage and systemic venous drainage. The primary endpoint was VGT with consideration of multiple relevant variables. The maximum amylase level was determined during the first 3 days after transplantation. A receiver operating characteristic analysis was performed to establish a cutoff point as (mean plus one standard deviation; 745 mg/dL), calculating the sensitivity, specificity, and predictive values. RESULTS: Recipient characteristics were 71% males with an overall mean age of 39 years (range, 23-55) and body mass index 24 (range, 19-36). The donor sex was similar. Mean donor age was 32 years with occurrences of hypotension in 9%, cerebrovascular brain death in 46%. Mean ischemia time was 10 hours and 45 minutes. Mean blood amylase peak was 395 mg/dL. Seven VGT cases were diagnosed during the postoperative period including six with complete thrombosis requring transplantectomy. Bivariate analysis showed the group of subjects with amylase levels above 745 mg/dL to display on eight-fold greater risk for VGT (odds ratio = 8.6; P = .032). The area under the curve of blood amylase peak during the first 3 days to detect VGT was 0.630 (95% confidence interval 0.41-0.84). CONCLUSIONS: A blood amylase peak above 745 mg/dL in the first 3 days after transplantation was associated with risk for VGT.

Removal of odorant dimethyl disulfide under alkaline and neutral conditions in biotrickling filters.

The aim of this paper was to evaluate the performance of biotrickling filters (BTFs) for treating low concentrations of dimethyl disulfide (DMDS), using different bacterial consortia adapted to consume reduced sulfur compounds under alkaline (pH ≈ 10) or neutral (pH ≈ 7) conditions. Solubility experiments indicated that the partition of DMDS in neutral and alkaline mineral media was similar to the value with distilled water. Respirometric assays showed that oxygen consumption was around ten times faster in the neutrophilic as compared with the alkaliphilic consortium. Batch experiments demonstrated that sulfate was the main product of the DMDS degradation. Two laboratory-scale BTFs were implemented for the continuous treatment of DMDS in both neutral and alkaline conditions. Elimination capacities of up to 17 and 24 g(DMDS) m(-3) h(-1) were achieved for the alkaliphilic and neutrophilic reactors with 100% removal efficiency after an initial adaptation and biomass build-up.

Effect of VOCs and methane in the biological oxidation of the ferrous ion by an acidophilic consortium.

During the elimination of H2S from biogas in an aqueous ferric sulphate solution, volatile organic compounds (VOCs) and methane are absorbed and may have an effect on the subsequent biological regeneration of ferric ion. This study was conducted to investigate the effect of maximum concentrations of methane and some VOCs found in biogas on the ferrous oxidation of an acidophilic microbial consortium (FO consortium). The presence and impact of heterotrophic microorganisms on the activity of the acidophilic consortium was also evaluated. No effect on the ferrous oxidation rate was found with gas concentrations of 1500 mg toluene m(-3), 1400 mg 2-butanol m(-3) or 1250 mg 1,2-dichloroethane m(-3), nor with methane at gas concentrations ranging from 15-25% (v/v). A tenfold increase in VOCs concentrations totally inhibited the microbial activity of the FO consortium and the heterotrophs. The presence of a heterotrophic fungus may promote the autotrophic growth of the FO consortium.

Conservative approach versus urgent appendectomy in surgical management of acute appendicitis with abscess or phlegmon.

BACKGROUND: Surgical management of acute appendicitis with appendiceal abscess or phlegmon remains controversial. We studied the results of initial conservative treatment (antibiotics and percutaneous drainage if necessary, with or without interval appendectomy) compared with immediate surgery. METHODS: We undertook an observational, retrospective cohort study of patients with a clinical and radiological diagnosis of acute appendicitis with an abscess or phlegmon, treated in our hospital between January 1997 and March 2009. Patients younger than 14, with severe sepsis or with diffuse peritonitis were excluded. A study group of 15 patients with acute appendicitis complicated with an abscess or phlegmon underwent conservative treatment. A control group was composed of the other patients, who all underwent urgent appendectomy, matched for age and later randomized 1:1. The infectious risk stratification was established with the National Nosocomial Infections Surveillance System (NNIS) index. Dependent variables were hospital stay and surgical site infection. Analysis was with SPSS, with p < 0.05 considered significant. RESULTS: Interval appendectomy was performed in 7 study group patients. Surgical site infection episodes were more frequent in the control group (6 vs. 0, p < 0.001). A greater percentage of high risk patients (NNIS ≥ 2) was identified in the control group (80 vs. 28.7%, p < 0.03), mostly related with contaminated or dirty procedures in this group (p < 0.001). No significant difference between groups was found in hospital stay. CONCLUSION: Initial conservative treatment should be considered the best therapeutic choice for acute appendicitis with abscess or phlegmon.

Resultados del tratamiento conservador inicial y de la cirugía urgente en la apendicitis aguda evolucionada / No disponible

Introducción: Existe controversia acerca del tratamiento idóneo de la apendicitis aguda evolucionada en forma de absceso o flemón. Realizamos un estudio para la evaluación de resultados del tratamiento conservador inicial (antibiótico y drenaje percutáneo si se precisa, con/sin apendicectomía diferida) y del tratamiento quirúrgico urgente. Método: Estudio observacional analítico de cohortes retrospectivas. Criterios de inclusión: pacientes con diagnóstico clínico y radiológico de apendicitis aguda evolucionada en forma de absceso o flemón, tratados en nuestro hospital entre enero 1997 y marzo 2009, excluyendo pacientes pediátricos, con sepsis grave o peritonitis difusa. En 15 pacientes con apendicitis complicada con absceso o flemón (cohorte de estudio) se indicó tratamiento conservador inicial. El grupo control se obtuvo del resto de pacientes (en todos ellos se indicó apendicectomía urgente) mediante un matching por edad y asignación aleatoria posterior (1:1). La estratificación del riesgo infeccioso se determinó mediante el índice National Nosocomial Infections Surveillance System (NNIS). Variables resultado: estancia global e infección de sitio quirúrgico. Se consideraron de relevancia estadística niveles de significación < 0,05. Resultados: En 7 pacientes del grupo de estudio se indicó apendicectomía diferida. La incidencia de episodios de infección de sitio quirúrgico fue significativamente mayor en el grupo control (6 vs. 0, p < 0,001). Un mayor porcentaje de pacientes con NNIS de alto riesgo (>= 2) se objetivó en el grupo control (80% vs. 28,7%, p < 0,03). El item determinante fue el carácter contaminado o sucio de las apendicectomías urgentes (p < 0,001). La estancia global no mostró diferencias significativas entre grupos. Conclusión: El tratamiento conservador inicial constituye la mejor alternativa terapéutica para la apendicitis aguda evolucionada(AU)

Background: Surgical management of acute appendicitis with appendiceal abscess or phlegmon remains controversial. We studied the results of initial conservative treatment (antibiotics and percutaneous drainage if necessary, with or without interval appendectomy) compared with immediate surgery. Methods: We undertook an observational, retrospective cohort study of patients with a clinical and radiological diagnosis of acute appendicitis with an abscess or phlegmon, treated in our hospital between January 1997 and March 2009. Patients younger than 14, with severe sepsis or with diffuse peritonitis were excluded. A study group of 15 patients with acute appendicitis complicated with an abscess or phlegmon underwent conservative treatment. A control group was composed of the other patients, who all underwent urgent appendectomy, matched for age and later randomized 1:1. The infectious risk stratification was established with the National Nosocomial Infections Surveillance System (NNIS) index. Dependent variables were hospital stay and surgical site infection. Analysis was with SPSS, with p < 0.05 considered significant. Results: Interval appendectomy was performed in 7 study group patients. Surgical site infection episodes were more frequent in the control group (6 vs. 0, p < 0.001). A greater percentage of high risk patients (NNIS >= 2) was identified in the control group (80 vs. 28.7%, p < 0.03), mostly related with contaminated or dirty procedures in this group (p < 0.001). No significant difference between groups was found in hospital stay. Conclusion: Initial conservative treatment should be considered the best therapeutic choice for acute appendicitis with abscess or phlegmon(AU)

Is liver transplantation without abdominal drainage safe?

UNLABELLED: This observational, analytical cohort consisted of 35 consecutive liver transplant (OLT) patients with no intra-abdominal drain and a control cohort of 35 subjects operated immediately before the former who had placement of an intra-abdominal drain. We sought to assess the impact of abdominal drainage on the diagnosis and prevention of early postoperative complications: hemoperitoneum, reinterventions, biliary leaks, or percutaneous drainage. We assessed variables related to the recipient (age, indication, pretransplant ascites, body mass index, Model for End-Stage Liver Disease score and rejection), the donor (age, steatosis, ischemia time) and intra- and postoperative factors (surgery time, blood product use, and coagulopathy). The end point was defined as the need for a reintervention, paracentesis, appearance, and drainage of collections as well as lengths of hospital and intensive care unit (ICU) stays. The postoperative ICU and in-hospital stays were similar between groups (3.7 vs 3.9 days and 12 vs 14 days, respectively). Two patients in the group with drainage were reoperated due to hemoperitoneum, whereas we did not reoperate any patients in the group without drainage. No patient from either group developed a biliary fistula or required drainage of an intra-abdominal collections. The need for paracentesis was greater among the group without drainage (23% vs 5.7%; P < .04) and among those with a prior history of severe ascites. Patients with drainage displayed a greater incidence of perihepatic hematomas by ultrasound (53% vs 21%; P < .08) and required more postoperative blood products, especially platelets (P > .04) and plasma (P < .01). CONCLUSION: OLT without intra-abdominal drainage is safe, not increasing morbidity. It seems likely that drainage may be responsible for intra-abdominal hematomas and greater consumption of blood products.

Epidemiology of appendectomy and appendicitis in the Valencian community (Spain), 1998-2007.

BACKGROUND/AIMS: Our purpose was to study the incidence of appendectomy and appendicitis in the Valencian community (Spain) during a period of 10 years (1998-2007). METHODS: Data on discharge diagnoses of appendectomy and appendicitis were downloaded from all public hospitals in the Valencian community. RESULTS: We identified 44,683 cases of appendectomies and 42,742 cases of appendicitis (95.7%) during the study period. The age-standardized incidence rates among men ranked between 132.1 cases per 100,000 population in 2003 and 117.46 cases per 100,000 population in 2000 without a clear trend through the study period. The appendiceal perforation rate was 12.1% and the negative appendectomy rate 4.3%. The global mortality was 0.38%. CONCLUSIONS: The incidence of appendectomy in our community presents a slight descending trend. This decline is more intense in females. The appendix perforation rate is lower than in other studies. The death rate is similar to other studies; however, it is very low in patients of younger age.

Biological sulfide removal under alkaline and aerobic conditions in a packed recycling reactor.

The biological sulfide removal from wastewater caustic streams can be achieved without significant dilution by alkaliphilic microorganisms which usually show lower growth and oxidation rates as compared with acidic and neutral bacteria. To improve volumetric removal rates under alkaline condition (pH 10), an Alkaliphilic Sulfide-oxidizing Bacteria Consortium (ASBC) was studied in a Packed Recycling Reactor (PRR). A commercial Nylon fiber resulted to be a convenient packing support for biofilm development as it has high specific area and similar hydrophobic propertie. The PRR reached a maximum sulfide oxidation rate of 100 mmol L(-1) d(-1) with efficiency close to 100%, representing an enhancement of 56% from the maximum sulfide oxidation rate reached for a free cell continuous culture. Higher sulfide loading rates induced oxygen limiting conditions reducing the biological activity despite the considerable biofilm attached on the nylon fiber.

Adverse effects on the lipid profile of immunosuppressive regimens: tacrolimus versus cyclosporin measured using C2 levels.

Immunosuppression has improved graft and recipient survival in transplantation but is accompanied by several adverse effects like dyslipidemia and cardiovascular disease. Herein, we performed an observational, descriptive study to analyze the relationship of dyslipemia (hypercholesterolemia [hypercho] and hypertriglyceridemia [hypertg]) and cardiovascular disease with two different immunosuppressive regimens in liver transplantation: cyclosporine treatment based upon C2 levels (CsA2) and tacrolimus (Tac), both in combination with steroids. Seventy-four liver transplantation patients were included during a 2-year period: 35 with CsA2 and 39 with Tac. The mean follow-up was 40 months. There were no significant differences between the groups in terms of age, gender, Model for End-stage Liver Disease Score, Child stage, and indication for transplantation. The distribution of patients with HyperCho and HyperTg was independent of the immunosuppressive agent (P = NS), both in a global and in a stratified analysis at 6, 12, 24, and 60 months. The analysis of cardiovascular events revealed no differences between the groups (CsA2 14.3%; Tac 18.9%; P = NS). We suggest that CsA monitoring using C2 levels shows a safety profile similar to that of Tac with regard to the development of dyslipidemia and cardiovascular events.

Impact of donor age on the results of liver transplantation in hepatitis C virus-positive recipients.

OBJECTIVE: Hepatitis C virus (HCV)-cirrhosis is the most frequent indication for orthotopic liver transplantation (OLT) among adults in most European and American transplant centers. The aim of this study was to analyze the impact of donor age on graft survival among HCV-positive cirrhotic transplant patients. MATERIALS AND METHODS: We performed an observational, retrospective study between March 1997 and December 2004, analyzing 340 liver transplantations. The patients were divided into 4 groups, considering whether the HCV infection was the indication for OLT and whether the age of the donor was older or younger than 48 years: group 1 (HCV, <48 years); group 2 (HCV, >48 years); group 3 (non-HCV, <48 years); and group 4 (non-HCV, >48 years). RESULTS: A univariate analysis showed that posttransplantation graft survival was clearly influenced by recipient HCV serologic status (P = .018). However, no graft survival differences were found when the analysis variable was age (>48 or <48 years). When both variables were studied, a positive HCV serology did not modify graft survival when the donor age was <48 years (P = .32), but had a statistically significant negative impact when the age was >48 years (P = .02). CONCLUSIONS: The use of older donors for HCV recipients resulted in worse graft and patient survivals in our study. This difference in survival was not present in non-HCV recipients or when grafts for HCV recipients were procured from younger donors. Donor age <30 years was a protective factor for graft survival among HCV recipients.

Influence of immunosuppression and effect of hepatitis C virus on new onset of diabetes mellitus in liver transplant recipients.

INTRODUCTION: New-onset posttransplantation diabetes mellitus (PTDM), with an incidence of 10% to 30%, increased graft and patient morbidity and mortality. Such causal factors as age, obesity, therapy, immunosuppression, and hepatitis C virus (HCV) contribute to this disease. OBJECTIVE: We sought to determine the incidence of PTDM and impaired fasting glucose (IFG) concentration in transplant recipients to define the causal variables. MATERIAL AND METHODS: The study included 127 patients. Patients with pretransplantation diabetes and those with less than 6 months of follow-up were excluded. A descriptive observational study to assess the association between PTDM and IFG and the immunosuppression therapy used was performed by monitoring the potential confounding variables of age, obesity, and HCV. RESULTS: During mean follow-up of 73.7 months (range, 7-120 mo), 93 patients received cyclosporine A (CyA) and 34 received tacrolimus (Tac) therapy. Thirty patients (23.6%) developed PTDM or IFG including 15 (16%; PTDM, six IFG, nine) in the CyA group and 15 (PTDM, seven; IFG, eight) in the Tacrolimus group (P = .001; odds ratio [OR], 4.1). They were homogeneous with respect to confounding variables except for HCV (P = .01). Of the 55 patients with HCV infection, 12 developed PTDM or IFG, including three in the CyA group and nine in the tacrolimus group (P = .03; OR, 7.7), whereas in the 72 patients without HCV infection, the CyA or tacrolimus association with PTDM or IFG was significant (P = .05), Mantel-Haenszel test; OR, 4.9). The interaction between HCV and immunosuppression therapy was primarily produced in the IFG group (HCV-positive; P = .008; OR, 8). CONCLUSION: We observed an association between the use of tacrolimus and the development of PTDM or IFG. There is greater risk in HCV-positive patients, in particular in relation to IFG. The choice of immunosuppressive treatment might be decided on the basis of the patient's pretransplantation status.

Sulfur formation and recovery in a thiosulfate-oxidizing bioreactor.

This work describes the design and performance of a thiosulfate-oxidizing bioreactor that allowed high elemental sulfur production and recovery efficiency. The reactor system, referred to as a Supernatant-Recycling Settler Bioreactor (SRSB), consisted of a cylindrical upflow reactor and a separate aeration vessel. The reactor was equipped with an internal settler and packing material (structured corrugated PVC sheets) to facilitate both cell retention and the settling of the formed elemental sulfur. The supernatant from the reactor was continuously recirculated through the aerator. An inlet thiosulfate concentration of 100 mmol l(-1) was used. The reactor system was fed with 89 mmol l(-1) d(-1) thiosulfate reaching 98 to 100% thiosulfate conversion with an elemental sulfur yield of 77%. Ninety-three percent of the produced sulfur was harvested from the bottom of the reactor as sulfur sludge. The dry sulfur sludge contained 87% elemental sulfur. The inclusion of an internal settler and packing material in the reactor system resulted in an effective retention of sulfur and biomass inside the bioreactor, preventing the oxidation of thiosulfate and elemental sulfur to sulfate in the aerator and, therefore, improving the efficiency of elemental sulfur formation and recovery.

True impact of the indication of cirrhosis and the MELD on the results of liver transplantation.

UNLABELLED: Our Aim was to determine the impact of cirrhosis and the preoperative MELD score on the immediate postoperative mortality and hospital stay as well as survival at 1, 5, and 8 years in liver transplantation. MATERIALS AND METHODS: Transplanted cirrhotic patients were selected who did not display some of the main known risk factors affecting recipient. Donor and surgical technique were included in this analysis. These exclusion criteria for recipient factors were emergency transplants and retransplants; for donor factors, age over 60 years, ischemia time over 10 hours, and moderate or severe steatosis on back-bench biopsy; and for surgery, prior complex upper abdominal surgery (mainly derivative and gastroduodenal surgery). Among 340 total liver transplants including 16 retransplants performed from March 1997 to December 2005, 197 patients met the selection criteria. The mean age of the recipients was 52 years (17-67) and the donors, 39 years (11-60). The transplant indication was cirrhosis in all cases: HCV in 69 cases (35%); alcohol in 55 (28%); hepatocarcinoma in 38 (19%); HBV in 19 (10%); PBC in 8 (4%), and other etiologies in 8 cases (4%). The MELD scores were divided as group 1, <10 points (33 cases = 17%); group 2, 10 to 18 points (136 cases = 69%); and group 3, >18 points (28 cases = 14%). The statistical analysis was performed with SPSS 11.0. RESULTS: Postoperative mortality (up to 3 months) was 16 cases (8%). The median ICU and hospital stays were 3 and 13.5 days, respectively. Overall survivals at 1, 5, and 8 years were 89%, 80%, and 77%, respectively. The survival for the same periods according to MELD group was 97%, 97%, and 97% for group 1; 87%, 76%, and 72% for group 2; and 85%, 81%, and 81% for group 3 (P = NS). The survival according to the three main indications at 1, 5, and 8 years was: HCV, 91%, 80%, and 80%; alcohol, 87%, 80%, and 71%; and hepatocarcinoma, 84%, 80%, and 80% (P = NS). No significant differences were observed among early deaths between MELD groups or transplant indications. CONCLUSIONS: In a favorable liver transplant setting including acceptable donors, absence of prior complex abdominal surgery in the recipient, and nonemergency transplants, neither the cause of the cirrhosis nor its severity, as measured preoperatively by the MELD, were predictive of early postoperative death or long-term survival.

Oxygen transfer and consumption in a thiosulfate oxidizing bioreactor with sulfur production.

AIMS: To evaluate the contribution of oxygen transfer and consumption in a sulfoxidizing system to increase the elemental sulfur yield from thiosulfate oxidation. METHODS AND RESULTS: A 10 l thiosulfate oxidizing bioreactor with suspended cells operating under microaerophilic conditions and a separated aerator with a variable volume of 0.8--1.7 l were operated with a consortium containing mainly Thiobacillus sp. that oxidizes several sulfide species to elemental sulfur and sulfate. From the gas-liquid oxygen balance, the k(L)a was estimated under different operation conditions. A k(L)a of around 200 h(-1) favoured elemental sulfur production and can serve as scale-up criterion. It was further shown that more than 50% of the oxygen fed to the system was consumed in the aerator. CONCLUSIONS: The performance of the sulfoxidizing system can be improved by controlling oxygen transfer. SIGNIFICANCE AND IMPACT OF THE STUDY: The proposed method for the k(L)a determination was based on the oxygen balance, which incorporates the oxygen concentrations measured in the liquid in steady state, reducing the interference of the response time in the traditional non-steady state methods. This approach can be used to optimize reactors where microaerophilic conditions are desirable.

Liver transplant results for hepatocellular carcinoma applying strict preoperative selection criteria.

INTRODUCTION: Liver transplantation is currently the best therapeutic option for small hepatocellular carcinoma (HC) in selected cirrhotic patients. The main aim of this study was to analyze the results of a recent series of liver transplant cirrhotic patients with small HC applying strict preoperative selection criteria. PATIENTS AND METHODS: During a period of 6 years we performed 53 liver transplants with a final diagnosis of HC on cirrhosis. The selection criteria for liver transplantation (LT) by modern imaging techniques were the Milan criteria (TNM I and II of the modified classification). RESULTS: Of the 53 patients, 44 (83%) were transplanted with preoperatively known HC, and 9 (17%) with incidental HC. The mean time on the waiting list was 74 +/- 62 days. Despite using strict selection criteria, 23 patients (43%) exceeded the Milan criteria in the specimen and 17 (32%) even exceeded the extended criteria of the UCSF. With a mean follow-up of 2 years, only two patients have developed recurrences. The overall survival at 1, 3, and 5 years was 80%, 70%, and 70%, respectively. The survival of patients that exceeded the Milan or USF criteria at 1, 3, and 5 years was 72% and 76%; 67% and 69%; 67% and 69%, respectively. CONCLUSIONS: The results of liver transplantation for HC are excellent when applying strict preoperative selection criteria. The current imaging methods lead to a considerable infrastaging percentage (30% to 40%), extending the indications for liver transplant due to HC beyond the scope that clinical reports would justify.

Preoperative factors and models predicting mortality in liver transplantation.

We analyzed preoperative factors related to postoperative mortality after liver transplantation among a cohort of 268 consecutive liver transplant patients over 6 years. We studied the impact of 10 recipient variables, 14 donor features, and three operative aspects. We also studied the correlation with death and survival using various predictive scores (Child, Cordoba Score, MELD, and UCLA). Univariate analysis showed that the factors with a significant association with postoperative mortality were the use of noradrenaline in the donor, total ischemia time (>12 hours), and transplant indication (hepatitis C virus versus the rest). Multivariate analysis of mortality showed the impact of female donor sex, recipients over >60 years, recipient albumin less than 2.8, and total graft ischemia time more than 12 hours. Univariate analysis of 1-year survival showed a statistically significant relation with D/R gender similarity, as well as donor GOT (>170) and GPT (>140) values. Multivariate analysis of 1-year survival showed donor GOT (>170) and donor/recipient gender similarity to be significant. Concerning the prediction models, Child-Pugh (AB versus C) best determined postoperative mortality (P < .006), MELD was predictive of 1-year survival (P < .03). The most important variables related to postoperative mortality were total ischemia time over 12 hours, recipient albumin less than 2.8, and age above 60 years. The variable with most impact on 1-year survival was the degree of graft hepatocyte lesion as determined by GOT. The Child-Pugh system is still the best indicator of postoperative mortality, although MELD may also be a good predictor of survival.