Degradation kinetics of sugars (glucose and xylose), amino acids (proline and aspartic acid) and their binary mixtures in subcritical water: Effect of Maillard reaction

A systematic kinetic study was conducted in subcritical water medium in the temperature range from 150 to 200 °C for pure glucose, xylose, proline and aspartic acid as well as binary mixtures of sugars + amino acids to understand the reaction kinetics and interactions among biomass components and to discern the influence of Maillard reaction (MR) on the overall reaction kinetics. The main degradation products identified for glucose and xylose were the respective dehydration products, hydroxymethyl furfural and furfural, yielding an increasing solid residue with temperature (15.9 wt% at 200 °C) with an augmented heating value. The degradation of sugars and amino acids in binary systems was faster compared to pure compounds due to MR and the production of dehydration products was delayed when considering total sugar conversion. Higher relative reactivity in MR was observed for xylose over glucose showing also higher antioxidant activity.

Microencapsulation of rice bran oil using pea protein and maltodextrin mixtures as wall material

In this work, the encapsulation of rice bran oil extracted using supercritical CO2 has been studied. In the first stage, the emulsification process by high pressure homogenization was studied and optimized. The effect of the working pressure (60-150 MPa), the composition of the carrier (mixtures of pea protein isolate (PPI) and maltodextrin (MD), from 50 to 90% of PPI) and the carrier to oil ratio (2-4) on the emulsion droplet size (EDS) was studied. To minimize the EDS, moderate pressures (114 MPa), a carrier composed mainly by PPI (64%) and carrier to oil ratios around 3.2 were required. The emulsion obtained in the optimal conditions (EDS = 189 ± 3nm) was dried using different technologies (spray-drying, PGSS-drying and freeze drying). The supercritical CO2 based drying process (PGSS) provided spherical particles that resulted in the smallest average size (but broader distribution) and lower encapsulation efficiency (53 ± 2%).

Exome sequencing identifies PEX6 mutations in three cases diagnosed with Retinitis Pigmentosa and hearing impairment

Purpose

The aim of the present work is the molecular diagnosis of three patients with deafness and retinal degeneration.

Methods

Three patients from two unrelated families were initially analyzed with custom gene panels for Usher genes, non-syndromic hearing loss, or inherited syndromic retinopathies and further investigated by means of clinical or whole exome sequencing.

Results

The study allowed us to detect likely pathogenic variants in PEX6, a gene typically involved in peroxisomal biogenesis disorders (PBDs). Beside deaf-blindness, both families showed additional features: Siblings from Family 1 showed enamel alteration and abnormal peroxisome. In addition, the brother had mild neurodevelopmental delay and nephrolithiasis. The case II:1 from Family 2 showed intellectual disability, enamel alteration, and dysmorphism.

Conclusions

We have reported three new cases with pathogenic variants in PEX6 presenting with milder forms of the Zellweger spectrum disorders (ZSD). The three cases showed distinct clinical features. Thus, expanding the phenotypic spectrum of PBDs and ascertaining exome sequencing is an effective strategy for an accurate diagnosis of clinically overlapping and genetically heterogeneous disorders such as deafness-blindness association.

The ethylene receptors CpETR1A and CpETR2B cooperate in the control of sex determination in Cucurbita pepo

High-throughput screening of an ethyl methanesulfonate-generated mutant collection of Cucurbita pepo using the ethylene triple-response test resulted in the identification of two semi-dominant ethylene-insensitive mutants: etr1a and etr2b. Both mutations altered sex determination mechanisms, promoting conversion of female into bisexual or hermaphrodite flowers, and monoecy into andromonoecy, thereby delaying the transition to female flowering and reducing the number of pistillate flowers per plant. The mutations also altered the growth rate and maturity of petals and carpels in pistillate flowers, lengthening the time required for flowers to reach anthesis, as well as stimulating the growth rate of ovaries and the parthenocarpic development of fruits. Whole-genome sequencing allowed identification of the causal mutation of the phenotypes as two missense mutations in the coding region of CpETR1A and CpETR2B, each one corresponding to one of the duplicates of ethylene receptor genes highly homologous to Arabidopsis ETR1 and ETR2. The phenotypes of homozygous and heterozygous single- and double-mutant plants indicated that the two ethylene receptors cooperate in the control of the ethylene response. The level of ethylene insensitivity, which was determined by the strength of each mutant allele and the dose of wild-type and mutant etr1a and etr2b alleles, correlated with the degree of phenotypic changes in the mutants.

Structural changes of a protein extract from apple with polyphenoloxidase activity obtained by cationic reversed micellar extraction induced by high-pressure carbon dioxide and thermosonication

Polyphenoloxidase from apple was extracted and further concentrated by cationic reversed micellar extraction. Previous to reversed micellar extraction a crude protein extract was obtained using AG2-X8 as adsorbent of phenolic compounds and the detergent Triton X-100. Forward and backward extraction conditions were optimized by using dodecyl trimethyl ammonium bromide as surfactant in the organic phase. Optimization was carried out to obtain the highest value of PPO activity recovery and the purification fold at the different experimental conditions. Under the optimum extraction conditions, PPO activity recovery was 99% and purification fold reached a value of 17, showing that reversed micellar extraction was a good technique as a first step to concentrate on a targeted enzyme. After removing some impurities by centrifuge ultrafiltration, the protein extract with PPO activity was treated by pressurized carbon dioxide and thermosonication achieving residual PPO activity values of 16 ± 3 and 9 ± 1%, respectively. Quenching experiments by iodide performed in the non-treated extract and in the treated extracts revealed conformational changes of this protein fraction reflected in the greater exposure of the fluorophore to the quencher.

Validation of a multi-phase plant-wide model for the description of the aeration process in a WWTP

This paper introduces a new mathematical model built under the PC-PWM methodology to describe the aeration process in a full-scale WWTP. This methodology enables a systematic and rigorous incorporation of chemical and physico-chemical transformations into biochemical process models, particularly for the description of liquid-gas transfer to describe the aeration process. The mathematical model constructed is able to reproduce biological COD and nitrogen removal, liquid-gas transfer and chemical reactions. The capability of the model to describe the liquid-gas mass transfer has been tested by comparing simulated and experimental results in a full-scale WWTP. Finally, an exploration by simulation has been undertaken to show the potential of the mathematical model.

Phenomic and Genomic Characterization of a Mutant Platform in Cucurbita pepo

The Cucurbita pepo genome comprises 263 Mb and 34,240 gene models organized in 20 different chromosomes. To improve our understanding of gene function we have generated an EMS mutant platform, consisting of 3,751 independent M2 families. The quality of the collection has been evaluated based on phenotyping and whole-genome re-sequencing (WGS) results. The phenotypic evaluation of the whole platform at seedling stage has demonstrated that the rate of variation for easily observable traits is more than 10%. The percentage of families with albino or chlorotic seedlings exceeded 3%, similar or higher to that found in other EMS collections of cucurbit crops. A rapid screening of the library for triple ethylene response in etiolated seedlings allowed the identification of four ethylene-insensitive mutants, that were found to be semidominant (ein1, ein2, and ein3) or dominant (EIN4). By evaluating 4 adult plants from 300 independent families more than 28% of apparent mutations were found for vegetative and reproductive traits, including plant vigor, leaf size and shape, sex expression and sex determination, and fruit set and development. Two pools of genomic DNA derived from 20 plants of two mutant families were subjected to WGS by using NGS methodology, estimating the density, spectrum, distribution and impact of EMS induced mutation. The number of EMS mutations in the genomes of families L1 and L2 was 1,704 and 859, respectively, which represents a density of 11.8 and 6 mutations per Mb, respectively. As expected, the predominant EMS induced mutations were C > T and G > A transitions (80.3% in L1, and 61% L2), that were found to be randomly distributed along the 20 chromosomes of C. pepo. The mutations were mostly affecting intergenic regions, but 7.9 and 6% of the identified EMS mutations in L1 and L2, respectively, were located in the exome, and 0.4 and 0.2% had a moderate and high putative impact on gene functions. These results provide information regarding the potential use of the obtained mutant platform in the discovery of novel alleles for both functional genomics and Cucurbita breeding by using direct- or reverse-genetic approaches.

Diagnosis and optimization of WWTPs using the PWM library: full-scale experiences

Given the shift in perception of wastewater treatment plants as water resource recovery facilities, conventional mathematical models need to be updated. The resource recovery perspective should be applied to new processes, technologies and plant layouts. The number and level of models proposed to date give an overview of the complexity of the new plant configurations and provides a wide range of possibilities and process combinations in order to construct plant layouts. This diversity makes the development of standard, modular and flexible tools and model libraries that allow the incorporation of new processes and components in a straightforward way a necessity. In this regard, the plant-wide modelling (PWM) library is a complete model library that includes conventional and advanced technologies and that allows economic and energetic analyses to be carried out in a holistic way. This paper shows the fundamentals of this PWM library that is built upon the above-mentioned premises and the application of the PWM library in three different full-scale case studies.

Growth phase-dependent control of R27 conjugation is mediated by the interplay between the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA and the cAMP regulon

Plasmids of the incompatibility group HI1 (IncHI1) have been isolated from several Gram-negative pathogens and are associated with the spread of multidrug resistance. Their conjugation is tightly regulated and it is inhibited at temperatures higher than 30°C, indicating that conjugation occurs outside warm-blooded hosts. Using R27, the prototype of IncHI1 plasmids, we report that plasmid transfer efficiency in E. coli strongly depends on the physiological state of the donor cells. Conjugation frequency is high when cells are actively growing, dropping sharply when cells enter the stationary phase of growth. Accordingly, our transcriptomic assays show significant downregulation of numerous R27 genes during the stationary phase, including several tra (transfer) genes. Growth phase-dependent regulation of tra genes transcription is independent of H-NS, a silencer of horizontal gene transfer, and ppGpp and RpoS, regulators of the stationary phase, but highly dependent on the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA. The metabolic sensor cAMP, whose synthesis is chromosomally encoded, is also involved in the growth phase regulation of R27 conjugation by modulating htdA expression. Our data suggest that the involvement of regulators encoded by both chromosome and plasmid are required for efficient physiological control of IncHI1 plasmid conjugation.

Exome Sequencing Reveals AMER1 as a Frequently Mutated Gene in Colorectal Cancer

PURPOSE

Somatic mutations occur at early stages of adenoma and accumulate throughout colorectal cancer progression. The aim of this study was to characterize the mutational landscape of stage II tumors and to search for novel recurrent mutations likely implicated in colorectal cancer tumorigenesis.

EXPERIMENTAL DESIGN

The exomic DNA of 42 stage II, microsatellite-stable colon tumors and their paired mucosae were sequenced. Other molecular data available in the discovery dataset [gene expression, methylation, and copy number variations (CNV)] were used to further characterize these tumors. Additional datasets comprising 553 colorectal cancer samples were used to validate the discovered mutations.

RESULTS

As a result, 4,886 somatic single-nucleotide variants (SNV) were found. Almost all SNVs were private changes, with few mutations shared by more than one tumor, thus revealing tumor-specific mutational landscapes. Nevertheless, these diverse mutations converged into common cellular pathways, such as cell cycle or apoptosis. Among this mutational heterogeneity, variants resulting in early stop codons in the AMER1 (also known as FAM123B or WTX) gene emerged as recurrent mutations in colorectal cancer. Losses of AMER1 by other mechanisms apart from mutations such as methylation and copy number aberrations were also found. Tumors lacking this tumor suppressor gene exhibited a mesenchymal phenotype characterized by inhibition of the canonical Wnt pathway.

CONCLUSIONS

In silico and experimental validation in independent datasets confirmed the existence of functional mutations in AMER1 in approximately 10% of analyzed colorectal cancer tumors. Moreover, these tumors exhibited a characteristic phenotype.

Colorectal adenomas contain multiple somatic mutations that do not coincide with synchronous adenocarcinoma specimens

We have performed a comparative ultrasequencing study of multiple colorectal lesions obtained simultaneously from four patients. Our data show that benign lesions (adenomatous or hyperplastic polyps) contain a high mutational load. Additionally multiple synchronous colorectal lesions show non overlapping mutational signatures highlighting the degree of heterogeneity between multiple specimens in the same patient. Observations in these cases imply that considering not only the number of mutations but an effective oncogenic combination of mutations can determine the malignant progression of colorectal lesions.

Lessons learnt from the application of a multi-variable controller for nitrogen removal in the Mekolalde wastewater treatment plant: good simulation practices in control

Although often perceived as tools for use by scientists, mathematical modelling and simulation become indispensable when control engineers have to design controllers for real-life wastewater treatment plants (WWTPs). Nonetheless, the design of effective controllers in the wastewater domain using simulations requires effects, such as the nonlinearity of actuators, the time response of sensors, plant model uncertainties, etc. to have been reproduced beforehand. Otherwise, control solutions verified by simulation can completely underperform under real conditions. This study demonstrates that, when all the above effects are included at the outset, a systematic use of simulations guarantees high quality controllers in a relatively short period of time. The above is exemplified through the Mekolalde WWTP, where a comprehensive simulation study was conducted in order to develop a control product for nitrogen removal. Since its activation in May 2011, the designed controller has been permanently working in the plant which, from this time onwards, has experienced significant improvements in the quality of water discharges combined with a lower utilization of electricity for wastewater treatment.

RNA polymerase II progression through H3K27me3-enriched gene bodies requires JMJD3 histone demethylase

JMJD3 H3K27me3 demethylase plays an important role in the transcriptional response to different signaling pathways; however, the mechanism by which it facilitates transcription is unclear. Genome-wide analysis shows that JMJD3 regulates TGFβ response by promoting RNA polymerase II progression along the gene bodies.

JMJD3 H3K27me3 demethylase plays an important role in the transcriptional response to different signaling pathways; however, the mechanism by which it facilitates transcription has been unclear. Here we show that JMJD3 regulates transcription of transforming growth factor β (TGFβ)–responsive genes by promoting RNA polymerase II (RNAPII) progression along the gene bodies. Using chromatin immunoprecipitation followed by sequencing experiments, we show that, upon TGFβ treatment, JMJD3 and elongating RNAPII colocalize extensively along the intragenic regions of TGFβ target genes. According to these data, genome-wide analysis shows that JMJD3-dependent TGFβ target genes are enriched in H3K27me3 before TGFβ signaling pathway activation. Further molecular analyses demonstrate that JMJD3 demethylates H3K27me3 along the gene bodies, paving the way for the RNAPII progression. Overall these findings uncover the mechanism by which JMJD3 facilitates transcriptional activation.

Genome-wide analysis reveals that Smad3 and JMJD3 HDM co-activate the neural developmental program

Neural development requires crosstalk between signaling pathways and chromatin. In this study, we demonstrate that neurogenesis is promoted by an interplay between the TGFβ pathway and the H3K27me3 histone demethylase (HDM) JMJD3. Genome-wide analysis showed that JMJD3 is targeted to gene promoters by Smad3 in neural stem cells (NSCs) and is essential to activate TGFβ-responsive genes. In vivo experiments in chick spinal cord revealed that the generation of neurons promoted by Smad3 is dependent on JMJD3 HDM activity. Overall, these findings indicate that JMJD3 function is required for the TGFβ developmental program to proceed.

Ambulatory blood pressure monitoring in renal transplant patients: should it be routinely performed?

INTRODUCTION

Arterial hypertension is common among kidney transplant patients. It increases cardiovascular risk and is a factor for progression of renal failure. Our objective was to perform ambulatory blood pressure monitoring (ABPM) in renal transplant patients with office hypertension.

METHODS

Patients were divided into 2 groups according to their mean ABPM blood pressures with treatment: well-controlled hypertension (blood pressure [BP] <130/85 mmHg), and poorly controlled hypertension (BP>130/85 mmHg). A "nondipper pattern" was defined as a decrease of <10% or an increase, and a "raiser pattern," in which mean blood pressure was greater during the nocturnal than the diurnal period. "White coat effect" was considered when the mean of 3 BP measurements in the clinic was >140/90 mmHg among well-controlled hypertensive patients as documented by ABPM.

RESULTS

ABPM was performed in 53 patients: 25 (47%) "well-controlled hypertensives" and 28 (53%) "poorly controlled hypertensives." Of the latter, 24 (85%) showed a nondipper or raiser pattern with only 4 revealing dipper patterns. We compared well-controlled with poorly controlled hypertensives. The latter cohort were older (54.4±9.3 vs 45.5±13.8 years; P=.009), received grafts from older donors (56.7±15.0 vs 45.8±17 years; P=.02); had worse renal function measured by serum creatinine (1.7±0.5 vs 1.4±0.4 mg/dL, P=.03) or the Modification of Diet in Renal Disease (MDRD)=4 formula (41.8±14.0 vs 55.4±20.5 mL/min/1.73 m2; P=.009), and displayed more proteinuria (0.30±0.33 vs 0.18±0.10 g/d, P=.08). Nondipper or raiser patients showed a higher mean body mass index (27.1 vs 21.7 kg/m2; P=.04). Among 25 well-controlled patients, 11 presented "white coat phenomenon."

CONCLUSION

We observed an important "white coat" effect, a large prevalence of uncontrolled nocturnal hypertension, and a small but important incident of "masked hypertension." Factors related to hypertension control were patient age, donor age, renal function, induction use, and proteinuria.

Automatic characterisation of primary, secondary and mixed sludge inflow in terms of the mathematical generalised sludge digester model

This paper presents the characterisation procedure of different types of sludge generated in a wastewater treatment plant to be reproduced in a mathematical model of the sludge digestion process. The automatic calibration method used is based on an optimisation problem and uses a set of mathematical equations related to the a priori knowledge of the sludge composition, the experimental measurements applied to the real sludge, and the definition of the model components. In this work, the potential of the characterisation methodology is shown by means of a real example, taking into account that sludge is a very complex matter to characterise and that the models for digestion also have a considerable number of model components. The results obtained suit both the previously reported characteristics of the primary, secondary and mixed sludge, and the experimental measurements specially done for this work. These three types of sludge have been successfully characterised to be used in complex mathematical models.

Renal allografts from donors older than 70 years are useful for single transplantation

Kidney transplantation has been related in elderly recipients to a greater longevity compared with dialysis. Due to the scarcity of donors, transplantation of older patients depends on the acceptance of older donors. We compared the characteristics and evolution of transplants from donors >or=70 years (n = 53) with those from donors >55-<70 years (n = 201). Group D >or=70 included older recipients (65.37 +/- 4.9 vs 55.92 +/- 9.66 years; P = .000) and more women (62.3% vs 45.3%; P = .02), with more peripheral arterial disease (10.9% vs 2.4%; P = .011). No differences in donor characteristics were observed. Induction treatment with thymoglobulin or basiliximab was more common in D >or=70 (81.1% vs 57.3%; P = .006), with no differences in other immunosuppressive drugs. The incidence of delayed graft function (DGF) was similar (P = .82), with a trend to a lower incidence of acute rejection episodes among D>or=70 (11.8% vs 22.5%; P = 0.09). Serum creatinine and proteinuria levels did not differ during follow-up (P > .05). Patients in D >or=70 displayed more episodes of urinary sepsis (19.1% vs 6.4%; P = .008), but no differences were observed in cytomegalovirus (CMV) infection (P = .629), neoplasia (P = .118), ischemic cardiopathy (P = .642), or hospital readmission due to infections (P = .567). Graft survivals at 5 years were 70% and 75% (P = .279) among groups D >or=70 and D>55-<70, respectively, and patient survivals at 5 years were 88% and 88% (P = .63), respectively. In conclusion, our study showed that selected kidneys from donors older than 70 years were followed with excellent graft and patient survivals, permitting older patients on renal replacement therapy to benefit from renal transplantation.

Histological findings of early graft biopsies in old donor renal transplant patients receiving induction therapy

Since recipients of transplants from elderly donors are exposed to an increased risk of delayed graft function (DGF) and acute rejection episodes, administration of induction treatment represents an alternative to preserve renal mass and improve graft survival. We compared the evolution and histological findings of early graft biopsies among 38 recipients treated with Thymoglobulim (33.6%) versus 75 (66.4%) with basiliximab. No differences were observes in the rate of DGF (P = .39). Forty kidneys were biopsed during the first 2 weeks after transplantation: 9 in the Thymoglobulin group (23.68%) and 31 in the basiliximab group (41.3%). Histological evaluation showed: acute tabular necrosis in 7 (78%) Thymoglobulin patients versus 14 (45%) basiliximab patients, with calcineurin nephrotoxicity in 2 (22%) and 1 (3.2%), respectively. An acute rejection episode was not diagnosed in the Thymoglobulin group, but 13 patients (17.3%) in the basiliximab group experienced this complication (P = .006). Banff classification showed: 6 grade IA (19.4%), 1 grade IB (3.2%), 3 grade IIA (9.7%), 1 grade IIB (3.2%), and 2 grade III (6.5%). Six of these patients required rescue treatment with Thymoglobulin. Serum creatinine and proteinuria levels between the 2 groups were not different (P > .05). There were no differences in cytomegalovirus (CMV) disease (P = .152), admission due to infection (P = .120), or neoplasia (P = .29). Graft and patient survivals at 3 years did not show a difference. The histological findings revealed that low doses of Thymoglobulin were much more effective to prevent renal inflammation and acute rejection episodes than basiliximab among renal transplant recipients, albiet without differences in survival at a mean of 3 years follow-up.

On-line estimation of suspended solids in biological reactors of WWTPs using a Kalman observer

The total amount of solids in Wastewater Treatment Plants (WWTPs) and their distribution among the different elements and lines play a crucial role in the stability, performance and operational costs of the process. However, an accurate prediction of the evolution of solids concentration in the different elements of a WWTP is not a straightforward task. This paper presents the design, development and validation of a generic Kalman observer for the on-line estimation of solids concentration in the tank reactors of WWTPs. The proposed observer is based on the fact that the information about the evolution of the total amount of solids in the plant can be supplied by the available on-line Suspended Solids (SS) analysers, while their distribution can be simultaneously estimated from the hydraulic pattern of the plant. The proposed observer has been applied to the on-line estimation of SS in the reactors of a pilot-scale Membrane Bio-Reactor (MBR). The results obtained have shown that the experimental information supplied by a sole on-line SS analyser located in the first reactor of the pilot plant, in combination with updated information about internal flow rates data, has been able to give a reasonable estimation of the evolution of the SS concentration in all the tanks.

Treatment of renal transplant failure

INTRODUCTION

Among graft failures beyond months, we performed progressive reduction and complete withdrawal of immunosuppressive drugs and steroids over a period of 6 months.

PATIENTS AND METHODS

We analyzed the treatment and complications associated with all late allograft failures in 34 patients (8.19%) out of 415 patients transplanted from November 1996 to November 2006.

RESULTS

In 21 patients (61.8%), the progressive reduction of immunosuppressive treatment was effective and well tolerated; however, in 13 patients (38.2%) there was rejection of the allograft at 10.74 +/- 8.95 months (0.77-34.80) after the failure. With the reintroduction of these drugs, the rejection was controlled in seven patients, but in the other six we had to embolize the allograft, which had to be repeated in one case. Embolization was well tolerated, but in one case there was migration of one coil to the femoral artery. One patient treated with drug withdrawal experienced emphysematous pyelonephritis after repeated urinary infections, requiring a nephrectomy. Thirteen (38.2%) of the patients with late failures have been admitted for a second transplant; five of them showed HLA sensitization.

CONCLUSIONS

Conservative treatment with progressive withdrawal of immunosuppression was effective and well tolerated in two-thirds of the patients with late renal allograft failure, but one-third of the patients rejected the graft and needed allograft embolization. Infection of the graft and HLA sensitization can complicate the course of these patients.

Effect of Overweight on Kidney Transplantation Outcome

INTRODUCTION

Obesity is a prevalent problem in renal transplant recipients that is followed by reduced graft and patient survivals. Because the prevalence of overweight (OW) is increasing in the renal transplant population, we studied the influence of OW on graft and recipient evolution.

PATIENTS AND METHODS

We analyzed a series of 337 patients with renal allografts having a mean follow-up of 53.4 +/- 30.6 months. We excluded 39 patients obese at transplantation. We compared the evolution of 134 OW patients (45.5%), and 160 patients (54.4%) with a body mass index <25 (NW group).

RESULTS

OW patients were older (P = .000) with a higher prevalence of hypertension (P = .028), left ventricular hypertrophy (P = .014), and dyslipidemia (P = .001). They had received kidneys from older donors (P = .019). OW patients showed a higher incidence of acute tubular necrosis (ATN) (P = .006), without a higher incidence of acute rejection episodes (P = .756). Postransplant diabetes mellitus was more frequent (P = .000), and systolic blood pressure (P < .05), total cholesterol (P < .05), and tryglicerides were higher (P < .05) in the OW group. Serum creatinine at 6 months (P = .007) and proteinuria >0.5 g/24 hours, (P = .023) were higher among the OW group. Graft survival was not different between groups, but patient survival was lower in the OW group (P = .002). A logistic regression analysis showed that the recipient age (RR: 5.243) and the presence of OW (RR: 1.100) were independent prognostic factors for patient death.

CONCLUSIONS

OW was a common situation among renal transplant candidates. It was associated with worse cardiovascular and metabolic profiles. OW patients showed worse allograft function and lower patient survival. A major effort must be exerted to avoid excessive weight gain, particularly among those OW at transplantation.

Benefits Derivated From Late Steroid Withdrawal in Renal Transplant Recipients

Because corticosteroids have adverse metabolic effects, inducing bone-mineral imbalance and contributing to infections among renal transplant recipients, many withdrawal trials have been attempted to reduce adverse events and improve quality of life. We retrospectively analyzed the safety and efficacy of late steroid withdrawal, after the first posttransplant year, among a selected group of kidney allograft recipients. In 42 low immunological risk allograft recipients, among 382 patients transplanted during a decade, corticosteroids were progressively reduced and completely withdrawn. The evolution of clinical and biochemical parameters after the withdrawal were analyzed. Corticosteroid withdrawal was performed as a mean of 52.16 +/- 28.41 months posttransplant, with subsequent follow-up without steroid treatment of 18.13 +/- 16.11 months. Comparing the most recent evaluation with the data previous to steroid withdrawal, patients showed a significant decreases in diastolic pressure (P = .039), total cholesterol (P = .000), and low-density lipoprotein cholesterol levels (P = .039), but not in triglyceride levels (P = .33). Body weight did not change (P = .77), but increased fasting glucose levels were noted (P = .03), in absence of new diagnosed diabetes mellitus. A significant reduction in cyclosporine Neoral (P = .01) or tacrolimus doses were detected (P = .01). At the last visit, serum creatinine in the whole group remained stable (P = .06). Only five patients showed an increase in serum creatinine more than 20% (from 1.44 +/- 0.41 to 1.94 +/- 0.45 mg/dL P = .04) and proteinuria did not increase (P = .94). No patient was diagnosed with a rejection episodes or required corticosteroid resumption. Graft and patient survivals were 100% at the end of follow-up. In conclusion, our data showed that late corticosteroid withdrawal in renal transplant recipients of low immunological risk is safe and is followed by an improvement in their metabolic profile and in blood pressure.

New mathematical procedure for the automatic estimation of influent characteristics in WWTPs

This paper proposes a new methodology for the automatic characterization of the influent wastewater in WWTP. With this methodology, model components are automatically estimated by means of optimization algorithms combining a-priori knowledge of the expected wastewater composition with experimental information from the available measurement data. The characterization is carried out based on an extended model components list in which components are described by means their elemental mass fractions. This allows an easy establishment of relationships between model components with experimental data and also, to obtain a general methodology applicable to any model used for wastewater biological treatments. The characterization of the wastewater influent of Galindo-Bilbao according this methodology has demonstrated its validity and the easy application to the ASM1 model influent characterization.

Erythropoietin treatment in the sixth posttransplant month as a prognostic factor for renal allograft survival

The purpose of this work was to assess the prognostic value of the need for erythropoietin (EPO) treatment at 6 months after transplantation. We retrospectively reviewed the outcomes of 143 consecutive cadaveric kidney transplants performed between January 2000 and April 2004, functioning at 6 months postransplantation. Patients were divided into two groups: group EPO6m (n = 24) received EPO treatment in the sixth month, and a control group (n = 119) did not receive EPO. Renal function deterioration (RFD) was considered to be a sustained decrease in creatinine clearance (CrCl) greater than 20% between the sixth month postransplant and the last visit. Mean follow-up was 38 +/- 16 months. The mean ages of the donor (57 +/- 9 vs 49 +/- 12 years; P = .001) and the recipient (59 +/- 12 vs 47 +/- 17 years; P = .000) were greater in the EPO6m group. Delayed graft function (83% vs 48%; P = .001) was more frequent in the EPO6m group. At 6 months after transplantation the EPO6m group showed lower hemoglobin (11.52 +/- 1.71 vs 13.32 +/- 1.69 g/dL; P = .000), higher serum creatinine (2.31 +/- 0.72 vs 1.65 +/- 0.53 mg/dL; P = .000), lower CrCl (33.53 +/- 10.83 vs 53.6 +/- 17.58 mL/min; P = .000), and similar proteinuria. RFD was more common in the EPO6m group (38% vs 10%; P = .026), with a different pattern of evolution of CrCl (-0.098 +/- 0.176 vs +0.093 +/- 0.396 mL/min/mo, P = .000). Multivariate analysis demonstrated that treatment with EPO at 6 months was the only predictor of RFD (RR 4.46; 1.58 to 12.58; P = .005). The need for EPO at 6 months postransplant was a good predictor of later renal allograft deterioration, more sensitive than serum creatinine or proteinuria.

Transplant Renal Artery Stenosis: Association With Acute Vascular Rejection

BACKGROUND

Transplant renal artery stenosis, the prevalence of which varies from 2% to 12%, is an important cause of hypertension and allograft dysfunction. We sought to determine the clinical characteristics of this disorder, assessing, predisposing factors, establishing treatment options, and examining patient outcomes.

PATIENTS AND METHODS

Among 321 renal allograft recipients between November 1996 and December 2004, six patients were identified with this finding. We analyzed their clinical data before and after treatment compared with the 315 recipients face of the disorder.

RESULTS

The six patients with the disorder were diagnosed within the first year (2 to 8 months; median 5.5 months). All patients displayed renal dysfunction, peripheral edema, and new-onset or uncontrolled hypertension at presentation. Abnormal Doppler findings were observed in 5 (83.3%) patients. The hemodynamically significant stenosis was successfully treated with percutaneous transluminal angioplasty (PTA) in all six. However, 3 (50%) patients displayed recurrent stenosis requiring a second PTA. The mean serum creatinine level decreased from a pre-PTA value of 4.4 +/- 1.8 mg/dL to a 1-month post-PTA value of 2.2 +/- 0.5 mg/dL (P = .027). Patients had no significant improvement in mean systolic and diastolic pressure. Vascular acute rejection episodes were more frequent among the affected than the control group (3/6; 50% vs 18/315; 5.7%; P < .001). No differences were found in age, sex, donor type, etiology of renal disease, immunosuppression, acute tubular necrosis, acute cellular rejection, cold ischemia time, or HLA matching.

CONCLUSION

Transplant renal artery stenosis is a common cause of hypertension and renal allograft dysfunction. Acute vascular rejection is associated with this disorder.

Extraction of natural complex phenols and tannins from grape seeds by using supercritical mixtures of carbon dioxide and alcohol

Proanthocyanidins are supposed to have some therapeutical properties as antioxidants and antineoplasics. Most of the proanthocyanidins, however, are not commercialized since their separation from natural sources is either very expensive or not well-known. In this work, the feasibility of application of mixtures of carbon dioxide and alcohol under supercritical conditions for selective extraction of some phenolic compounds from grape seeds has been studied, among them some low polymerized proanthocyanidins, their main monomer units, (+)-catechin and (-)-epicatechin, and some low molecular weight phenolic compounds, like gallic acid. An analytical-scale supercritical fluid extractor, whose operation was previously optimized, was used to carry out the experiments. A commercial concentrate of complex phenols and tannins from grape seeds was subjected to supercritical extraction in order to find the best operation conditions before directly extracting defatted milled grape seeds. The solvent capacity was found to increase with pressure and with the amount of alcohol used as cosolvent as expected. Such variation in solvent capacity could be used for design of a selective separation process where individual phenolic compounds or groups of them could be obtained. HPLC coupled with two types of detectors, diode array and mass spectrometry, was used for tentative identification and quantification of complex phenols and tannins in the extracts and in the raw materials used for extraction.

Various applications of liquid chromatography-mass spectrometry to the analysis of phenolic compounds

Different options of liquid chromatography-mass spectrometry were used to establish the most suitable ion source and conditions to analyse or detect some low-molecular mass phenols, flavan-3-ols, and apply such conditions to a complex sample (wine). Data presented in this work confirm the great utility of atmospheric pressure-ionisation electrospray mass spectrometry coupled to HPLC for analysis of phenolic compounds, under negative mode in the case of low-molecular mass phenols, and under both positive and negative modes in flavan-3-ol compounds. A fragmentor voltage of 60 V could be the most suitable for analysing the compounds under study.

[Chronic gastritis in children (author's transl)]

The gastric mucosa in 113 children from 6 months to 14 years old was studied from a histopathological point of view. Samples were obtained by means of a multiple biopsy technique during an endoscopic examination. The patients were divided into two groups. Group A was composed of 97 children with abdominal pain of an unknown etiology. Group B was formed of 16 patients with extragastric pathology in whom it was possible to take biopsies during an endoscopic exam. All of the biopsies were normal, and therefore were used as the control group. 49 patients from group A were histologically normal. In the other 48, lesions of chronic gastritis ranging in severity, were found in the antrum and/or in the gastric body. An analysis of the histopathological findings, and of the lesional sings of activity was done in accordance with Whitehead's criteria. Macroscopic objective features observed during the endoscopical examinations, were also evaluated and compared with the existence or nonexistence of chronic gastritis lesions. In the gastric body, the existence of endoscopic features such as enlarged folds, erosions or friable mucosa, were found to be coincident with the presence of histologic lesions of chronic gastritis. The same relationship was found in the antrum between the granular mucosa and/or irregular coloration and the lesions of chronic gastritis. In the same time, acid secretion studies (BAO, MAO and PAO) from 40 patients from group A were done using pentagastrin as a stimulant. It was demonstrated that both basal acid output and maximal acid were significantly lowered in cases of advanced lesions of chronic gastritis located in the gastric body. Finally the importance of this entity is emphasized in the gastrointestinal pathology in children.