Belief That Caffeine Ingestion Improves Performance in a 6-Minute Time Trial Test without Affecting Pacing Strategy

This study aimed to analyze the placebo effect associated with caffeine ingestion on running performance.

METHODS

Thirteen recreationally trained males in long-distance running (age: 38.5 ± 11.9 years, 11.0 ± 8.8 years of running experience) performed a 6 min time trial test in each experimental condition (caffeine-informed/placebo ingested (placebo) and non-ingested (control)) separated by 7 days. The total distance covered was measured, and partial times of each 400 m were used to analyze the pacing strategy. Heart rate and kinematic variables were recorded for each split. In addition, the rate of perceived exertion and prevalence of caffeine side effects was measured using questionnaires.

RESULTS

Placebo ingestion improved running performance in the 6 min time trial test (1668 ± 139 m placebo vs. 1642 ± 158 m control, t = 2.49; p = 0.03; moderate ES = 0.69), while pacing, heart rate, RPE, and kinematic variables were similar between conditions (p > 0.05 in all cases). Minor side effects were reported.

CONCLUSIONS

Beliefs of caffeine ingestion can improve running performance at speeds around maximal aerobic speed in recreationally trained runners without affecting pacing strategy so this "nutritional" strategy could be useful in competition scenarios. As a practical application, recreationally trained runners could improve ≈5 s in 1500 m or mile competitions.

NOM fractionation by HPSEC-DAD-OCD for predicting trihalomethane disinfection by-product formation potential in full-scale drinking water treatment plants

Chlorination is a common method for water disinfection; however, it leads to the formation of disinfection by-products (DBPs), which are undesirable toxic pollutants. To prevent their formation, it is crucial to understand the reactivity of natural organic matter (NOM), which is considered a dominant precursor of DBPs. We propose a novel size exclusion chromatography (SEC) approach to evaluate NOM reactivity and the formation potential of total trihalomethanes-formation potentials (tTHMs-FP) and four regulated species (i.e. CHCl_3, CHBrCl_2, CHBr₂Cl, and CHBr₃). This method combines enhanced SEC separation with two analytical columns working in tandem and quantification of apparent molecular weight (AMW) NOM fractions using C content (organic carbon detector, OCD), 254-nm spectroscopic (diode-array detector, DAD) measurements, and spectral slopes at low (S_206-240) and high (S_350-380) wavelengths. Links between THMs-FP and NOM fractions from high performance size exclusion chromatography HPSEC-DAD-OCD were investigated using statistical modelling with multiple linear regressions for samples taken alongside conventional full-scale as well as full- and pilot-scale electrodialysis reversal and bench-scale ion exchange resins. The proposed models revealed promising correlations between the AMW NOM fractions and the THMs-FP. Methodological changes increased fractionated signal correlations relative to bulk regressions, especially in the proposed HPSEC-DAD-OCD method. Furthermore, spectroscopic models based on fractionated signals are presented, providing a promising approach to predict THMs-FP simultaneously considering the effect of the dominant THMs precursors, NOM and Br^-.

Screening of microplastics in water and sludge lines of a drinking water treatment plant in Catalonia, Spain

Microplastics (MPs) are emerging pollutants detected everywhere in the environment, with the potential to harm living organisms. The present study investigated the concentration, morphology, and composition of MPs, between 20 μm and 5 mm, in a drinking water treatment plant (DWTP) located close to Barcelona (Catalonia, NE Spain). The sampling included different units of the DWTP, from influent to effluent as well as sludge line. Sampling strategy, filtration, allows sampling of large volumes of water avoiding sample contamination, and during 8 h in order to increase the representativeness of MPs collected. The pre-treatment of the samples consisted of advanced oxidation with Fenton's reagent and hydrogen peroxide, followed by density separation of the particles with zinc chloride solution. Visual identification was performed with an optical and stereoscopic microscope with final Fourier-transform infrared spectroscopic (FTIR) confirmation. MPs were found in all DWTP samples, with concentrations from 4.23 ± 1.26 MPs/L to 0.075 ± 0.019 MPs/L in the influent and effluent of the plant, respectively. The overall removal efficiency of the plant was 98.3%. The most dominant morphology was fibers followed by fragments and films. Twenty-two different polymer types were identified and synthetic cellulose, polyester, polyamide, polypropylene, polyethylene, polyurethane, and polyacrylonitrile were the most common. Although MPs could be incorporated from the distribution network, MPs intake from drinking water from this DWTP was not an important route compared to fish and seafood ingestion.

Benchmarking empirical models for THMs formation in drinking water systems: An application for decision support in Barcelona, Spain

Drinking water treatment plants (DWTPs) face changes in raw water quality, which affect the formation of disinfection by-products. Several empirical modelling approaches have been reported in the literature, but most of them have been developed with lab-scale data, which may not be representative of real water systems. Therefore, the application of these models for real-time operation of DWTPs might be limited. At the present study, multiple linear regression (MLR) and multi-layer perceptrons (MLP) were benchmarked using field-scale data for predicting the THMs formation in a case-study DWTP in Barcelona, Spain. After fitting the studied models, MLR exhibited good fit with the validation data set (R² = 0.88 and MAE = 4.0 μg·L^-1) and described the most plausible input-output relationships with field-scale data. The MLR predictive model was incorporated into an environmental decision support system (EDSS) for assessing the THMs formation at two critical points of the distribution network. A Monte Carlo scheme was applied for quantifying uncertainty of model predictions at these points, considering low and high water quality scenarios and different degrees of treatment by an electrodialysis reversal process. The results show that the use of the proposed EDSS can help in real operation of complex drinking water systems, which face important changes in water quality throughout the year.

Assessment of dead-end ultrafiltration for the detection and quantification of microbial indicators and pathogens in the drinking water treatment processes

A safe water supply requires distinct treatments and monitoring to guarantee the absence of pathogens and substances potentially hazardous for human health. In this study we assessed the efficiency of the dead-end ultrafiltration (DEUF) method to concentrate faecal indicator organisms (FIO) and pathogens in water samples with different physicochemical characteristics. Water samples were collected at the treatment stages of two drinking water treatment plants to analyse the concentration of a variety of 7 FIO and 4 reference microbes which have some species that are pathogenic to humans: Campylobacter spp., enteroviruses, Cryptosporidium spp. and Giardia spp. The samples were analysed before and after concentration by DEUF, detecting FIO concentrations about 1 log₁₀ higher in non-concentrated samples from both catchments. Percent recoveries were highly variable with a mean of 43.8 ± 17.5%, depending on the FIO and inherent sample characteristics. However, DEUF enabled FIO concentration in high volumes of water (100-500 l), allowing a reduction in the detection limit compared to the non-concentrated samples due to the high volume processing capabilities of the method. As a consequence, the detection of FIO removal from water in the drinking water treatment process was 1.0-1.5 logarithms greater in DEUF-treated water compared to unfiltered samples. The DEUF method improved the detection of target indicators and allowed for the detection of pathogens in low concentrations in water after the treatment stages, confirming the suitability of DEUF to concentrate high volumes of different types of water. This method could be useful for microbial analysis in water treatment monitoring and risk assessment, allowing the identification of critical points during the water treatment process and potential hazards in water destined for several uses.

Implementation of an environmental decision support system for controlling the pre-oxidation step at a full-scale drinking water treatment plant

Drinking water treatment plants (DWTPs) face changes in raw water quality, and treatment needs to be adjusted to produce the best water quality at the minimum environmental cost. An environmental decision support system (EDSS) was developed for aiding DWTP operators in choosing the adequate permanganate dosing rate in the pre-oxidation step. To this end, multiple linear regression (MLR) and multi-layer perceptron (MLP) models are compared for choosing the best predictive model. Besides, a case-based reasoning (CBR) model was approached to provide the user with a distribution of solutions given similar operating conditions in the past. The predictive model consisted of an MLP and has been validated against historical data with sufficient good accuracy for the utility needs (R² = 0.76 and RSE = 0.13 mg·L^-1). The integration of the predictive and the CBR models in an EDSS gives the user an augmented decision-making capacity of the process and has great potential for both assisting experienced users and for training new personnel in deciding the operational set-point of the process.

Chemical characterization and relative toxicity assessment of disinfection byproduct mixtures in a large drinking water supply network

In order to reduce the formation of disinfection by-products (DBPs) during potabilization of water it is necessary to explore the potential of the source water and the applied treatment to generate these chemicals. This is actually more challenging in large drinking water networks that use different source waters to satisfy drinking water demand. In this regard, this work investigated the formation of DBPs in water matrices that are commonly supplied to the city of Barcelona and its metropolitan area. The regulated trihalomethanes and haloacetic acids were the most abundant DBP classes in these waters, followed by haloacetamides and haloacetonitriles or trihalogenated acetaldehydes (THALs). On the contrary, the formation potential of iodo-DBPs was minor. Mixing of drinking water treatment plant finished waters with desalinated water decreased the overall DBP formation potential of the water but resulted in the increased formation of brominated DBPs after long chlorine contact time. The formation of most DBPs was enhanced at high water temperatures (except for Br-THALs) and increasing residence times. Potential cytotoxicity and genotoxicity of the DBP mixtures were mainly attributed to the presence of nitrogen-containing DBPs and HAAs.

Biodiesel production from crude Jatropha oil catalyzed by non-commercial immobilized heterologous Rhizopus oryzae and Carica papaya lipases

The aim of this study was to evaluate the feasibility of biodiesel production by transesterification of Jatropha oil with methanol, catalyzed by non-commercial sn-1,3-regioselective lipases. Using these lipases, fatty acid methyl esters (FAME) and monoacylglycerols are produced, avoiding the formation of glycerol as byproduct. Heterologous Rhizopus oryzae lipase (rROL) immobilized on different synthetic resins and Carica papaya lipase (rCPL) immobilized on Lewatit VP OC 1600 were tested. Reactions were performed at 30°C, with seven stepwise methanol additions. For all biocatalysts, 51-65% FAME (theoretical maximum=67%, w/w) was obtained after 4h transesterification. Stability tests were performed in 8 or 10 successive 4h-batches, either with or without rehydration of the biocatalyst between each two consecutive batches. Activity loss was much faster when biocatalysts were rehydrated. For rROL, half-life times varied from 16 to 579h. rROL on Lewatit VPOC 1600 was more stable than for rCPL on the same support.

Evaluation of emerging contaminants in a drinking water treatment plant using electrodialysis reversal technology

Emerging contaminants (EC) have gained much attention with globally increasing consumption and detection in aquatic ecosystems during the last two decades from ng/L to lower ug/L. The aim of this study was to evaluate the occurrence and removal of pharmaceutically active compounds (PhACs), endocrine disrupting chemicals (EDCs) and related compounds in a Drinking Water Treatment Plant (DWTP) treating raw water from the Mediterranean Llobregat River. The DWTP combined conventional treatment steps with the world's largest electrodialysis reversal (EDR) facility. 49 different PhACs, EDCs and related compounds were found above their limit of quantification in the influent of the DWTP, summing up to a total concentration of ECs between 1600-4200 ng/L. As expected, oxidation using chlorine dioxide and granular activated carbon filters were the most efficient technologies for EC removal. However, despite the low concentration detected in the influent of the EDR process, it was also possible to demonstrate that this process partially removed ionized compounds, thereby constituting an additional barrier against EC pollution in the product. In the product of the EDR system, only 18 out of 49 compounds were quantifiable in at least one of the four experimental campaigns, showing in all cases removals higher than 65% and often beyond 90% for the overall DWTP process.

Molecular and flow cytometry characterization during the follow-up of three simultaneous lymphoproliferative disorders: hairy cell leukemia, monoclonal B-cell lymphocytosis, and CD4(++) /CD8(+/- dim) T-large granular lymphocytosis--a case report

The simultaneous diagnosis of hairy cell leukemia and monoclonal B-cell lymphocytosis with the characteristics of "indolent" chronic lymphocytic leukemia is rare but not unknown. However, an association with a third clonal lymphoproliferative disorder has not previously been described. We report the simultaneous presence of hairy cell leukemia, monoclonal B-cell lymphocytosis, and alpha beta CD4(++) /CD8(+) T-cell large granular lymphocytosis in a 63-year-old man. After the diagnosis, the three lymphoproliferative disorders (i.e., two of B-cell lineage and one of T-cell lineage) were characterized by analysis of multiple sequential bone marrow and peripheral blood samples using flow cytometry and molecular techniques. We discuss these findings in the context of chronic antigen stimulation, immunosuppression, and apoptotic pathway alterations, which might be implicated in the accumulation of these abnormal clones in the same patient. Because the phenotype of the three clones is compatible with fully differentiated B lymphocytes (consistent with a postgerminal origin) and T-CD4(++) cells, we favor the possibility of an antigen-driven mechanism and a dysregulation of homeostatic apoptosis in this patient.

Protection against anti-citrullinated protein antibody-positive rheumatoid arthritis is predominantly associated with HLA-DRB1*1301: a meta-analysis of HLA-DRB1 associations with anti-citrullinated protein antibody-positive and anti-citrullinated protein antibody-negative rheumatoid arthritis in four European populations

OBJECTIVE

The protective effect of HLA-DRB1 alleles on the development of rheumatoid arthritis (RA) is poorly understood. The aim of this study was to perform a meta-analysis of 4 European populations to investigate which HLA-DRB1 alleles are associated with protection in anti-citrullinated protein antibody (ACPA)-positive RA and ACPA-negative RA.

METHODS

Data for >2,800 patients and >3,000 control subjects for whom information on HLA-DRB1 typing and ACPA status was available were collected from 4 European countries: Norway, Sweden, The Netherlands, and Spain. The odds ratios (ORs) and 95% confidence intervals (95% CIs) associated with the different HLA-DRB1 alleles were analyzed in a combined meta-analysis focused on protective alleles and classifications. The analysis of ACPA-positive RA was stratified for the shared epitope (SE) alleles, to correct for skewing due to this association.

RESULTS

In ACPA-positive RA, the only alleles that conveyed protection after stratification for SE were HLA-DRB1*13 alleles (OR 0.54 [95% CI 0.38-0.77]). The protective effect of the allele classifications based on the DERAA and D70 sequences was no longer present after exclusion of DRB1*13 (for D70, OR 0.97 [95% CI 0.75-1.25]), indicating that DRB1*13, rather than the DERAA or D70 sequence as such, is associated with protection. Among the DRB1*13 alleles, only DRB1*1301 was associated with protection (OR 0.24 [95% CI 0.09-0.59]). Protection appeared to follow a north-to-south gradient, with the strongest association in northern European countries. In ACPA-negative RA, there were no robust associations with HLA-DRB1 alleles.

CONCLUSION

Our data do not support any of the classifications of protective alleles and indicate that protection against ACPA-positive RA is predominantly associated with HLA-DRB1*1301.

N-acetylcysteine exerts protective effects and prevents lung redox imbalance and peroxynitrite generation in endotoxemic rats

The aim of this study was to determine in endotoxemic rats the effects of N-acetylcysteine on lung redox imbalance and plasma peroxynitrite generation. Eighty male Wistar rats were divided in two sets of five experimental groups. Six hours after vehicle (Control group: isotonic NaCl sterile solution i.p.; n=7), lipopolysaccharide (LPS group: 1 mg/Kg i.p.; n=8), N-acetylcysteine plus LPS (NAC+LPS group, n=8), NAC plus the nitric oxide synthesis inhibitor N(w)-nitro-L-arginine methyl ester plus LPS (NAC+NAME+LPS group; n=8), or NAME plus LPS (NAME+LPS group; n=9), arterial blood and lung samples were taken from each animal under sodium pentobarbital anesthesia. In five additional groups treated as described above, in vivo plasma oxidation of dihydrorhodamine (DRH) 123 to rhodamine (RH)123 was measured as index of peroxynitrite formation. LPS treated rats presented increased plasma lactate, thrombocytopenia and both, decreased reduced thiols and increased lipid peroxidation in lung tissue. Moreover, LPS produced increments in plasma concentration of nitrites/nitrates and DRH 123 oxidation. Pretreatment with NAC prevented all these changes induced by LPS except the increment in plasma concentration of nitrites/nitrates. The protective effects seen in LPS rats pretreated with NAC were not observed in the NAC+NAME+LPS group. In conclusion, the results of this study show that in endotoxemia induced by LPS in rats, NAC produces protective effects on lung redox balance and prevents peroxynitrite anion generation.

Occurrence of Cryptosporidium spp. oocysts in raw and treated sewage and river water in north-eastern Spain

AIMS

To determine the occurrence and levels of Cryptosporidium parvum oocysts in wastewater and surface waters in north-eastern Spain.

METHODS AND RESULTS

Samples from five sewage treatment plants were taken monthly and quarterly during 2003. In addition, water was collected monthly from the River Llobregat (NE Spain) during the period from 2001 to 2003. All samples were analysed by filtration on cellulose acetate filters or through Envirocheck using EPA method 1623, followed by immunomagnetic separation and examination by laser scanning cytometry. All raw sewage, secondary effluent and river water samples tested were positive for Cryptosporidium oocysts. Of the tertiary sewage effluents tested, 71% were positive for Cryptosporidium oocysts. The proportion of viable oocysts varied according to the sample.

CONCLUSIONS

Two clear maxima were observed during spring and autumn in raw sewage, showing a seasonal distribution and a correlation with the number of cryptosporidiosis cases and rainfall events.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides the first data on the occurrence of Cryptosporidium oocysts in natural waters in north-eastern Spain.

Improving the monitoring of methanol concentration during high cell density fermentation of Pichia pastoris

The Pichia pastoris expression system is widely used for the production of recombinant proteins. A simple and efficient experimental set-up allowing on-line monitoring of the methanol concentration during the fermentation of P. pastoris based on the detection of the methanol vapor concentration in the exhaust air from fermenter by a tin dioxide (SnO2) semiconductor sensor is described. An experimental procedure to allow precise calibration of the system and to reduce methanol sensor's interferences (>95% reduction) are also presented and discussed. Accuracy and measurement error were estimated about 0.05 g x l(-1) and 6%, respectively. The efficient monitoring of methanol will help to advanced control of recombinant protein production and process optimization.

Acute renal hemodynamic effects of dimanganese decacarbonyl and cobalt protoporphyrin

BACKGROUND

Heme oxygenase (HO) products have a protective role in acute renal failure (ARF) that may be hemodynamically mediated because the HO-derived carbon monoxide (CO) is an important control system of arteriolar tone. The vascular effects of HO may be caused directly through changes in CO synthesis, and indirectly by alterations in nitric oxide (NO) release. The present study evaluated in vivo the renal effects of a heme oxygenase inhibitor, Co(III)Protoporphyrin (CoPP) alone or in combination with the CO donor dimanganese decacarbonyl (Mn2(CO)10).

METHODS

All drugs were administered into the renal artery of anesthetized rats. Changes in renal cortical nitric oxide concentration were measured in vivo electrochemically.

RESULTS

The intrarenal administration of the CO donor Mn2(CO)10 increased blood carboxyhemoglobin levels (+74%), renal blood flow (+54%), glomerular filtration (+38%), and urinary cGMP excretion (+128%). On the other hand, the inhibition of renal HO with CoPP progressively induced an ARF characterized by a drop in renal blood flow (-77%), glomerular filtration (-93%), and urinary cGMP excretion (-93%). These deleterious effects of HO inhibition on renal function were nearly abolished by supplementing CO with the coadministration of Mn2(CO)10+ CoPP, indicating that they may be caused by inhibition of CO synthesis and the resulting hemodynamic changes. In addition, CoPP lowered the renal cortical NO concentration (-21%) and also decreased the urinary excretion of nitrates/nitrites, while Mn2(CO)10 increased renal NO levels (+20%) and raised the excretion of nitrates/nitrites, suggesting that changes in NO release may contribute to the renal effects of the HO-CO system.

CONCLUSION

These results indicate that heme oxygenase-derived CO plays a cardinal role in the control of renal hemodynamics and glomerular filtration.

Assessment of drinking water quality using indicator bacteria and bacteriophages

Bacterial indicators and bacteriophages suggested as potential indicators of water quality were determined by public laboratories in water from springs, household water wells, and rural and metropolitan water supplies in north-eastern Spain. Indicator bacteria were detected more frequently than bacteriophages in springs, household water wells and rural water supplies. In contrast, positive bacteriophage detections were more numerous than those of bacteria in metropolitan water supplies. Most of the metropolitan water supply samples containing indicators had concentrations of chlorine below 0.1 mg l(-1), their indicator loads resembling more closely those of rural water supplies than any other samples taken from metropolitan water supplies. The number of samples from metropolitan water supplies containing more than 0.1 mg l(-1) of chlorine that contained phages clearly outnumbered those containing indicator bacteria. Some association was observed between rainfall and the presence of indicators. Sediments from service reservoirs and water from dead ends in the distribution network of one of the metropolitan water supplies were also tested. Bacterial indicators and phages were detected in a higher percentage than in samples of tap water from the same network. Additionally, indicator bacteria were detected more frequently than bacteriophages in sediments of service reservoirs and water from dead end samples. We conclude that naturally occurring indicator bacteria and bacteriophages respond differently to chlorination and behave differently in drinking water distribution networks. Moreover, this study has shown that testing for the three groups of phages in routine laboratories is easy to implement and feasible without the requirement for additional material resources for the laboratories.

On-line monitoring of the methanol concentration in Pichia pastoris cultures producing an heterologous lipase by sequential injection analysis

An automated sequential injection analysis (SIA) system using stop-flow technique was developed to determine methanol concentration by means of the enzymatic reactions of alcohol oxidase and peroxidase. Its application as an on-line device for monitoring Pichia pastoris fermentations producing an heterologous protein was demonstrated. Linear response, observed up to 2 g l(-1), was reached by including a dilution chamber in the SIA manifold. The sampling frequency was 7 analyses per hour with a relative standard deviation lower than 4%.

Vaginal misoprostol 800 μg every 12 h for second-trimester abortion

The objective of the study was to evaluate the efficacy and safety of 800 microg misoprostol every 12 h, up to three doses, for pharmacological second-trimester abortion. The misoprostol doses were always administered by doctors into the vagina. Two-hundred and sixty-nine women with gestations within 12 and 20 weeks were recruited into the study. The main outcomes measured were successful abortion (passage of fetus and placenta without surgery), side effects and mean drop in hemoglobin, vaginal bleeding and mean time of return of menstruation. Complete abortion occurred in 245/269 (91.1%, 95% confidence interval 87-94%) patients. Vaginal bleeding lasted 15.7 +/- 4.1 days. The mean drop in hemoglobin, calculated 24 h after abortion, were statistically significant (p = 0.0001), as also was the mean hemoglobin measured 14 days after abortion, but without clinical relevance. According to the results obtained, 800 microg of misoprostol administered every 12 h, up to a maximum of three doses, could be a valid method for abortion within 12 and 20 weeks of gestation.

Nuisance odours produced by benthic cyanobacteria in a Mediterranean river

Geosmin dynamics in the Llobregat waters were related to the waxing and waning of benthic cyanobacterial mats developing in the river. Geosmin concentration in the water during 2002 reached a maximum of 204 ng L(-1), and coincided with an abundance of cyanobacteria in the river. Cyanobacterial mats were favoured by the high nutrient content of the waters. The cyanobacterial mats experienced a process of growth in thickness (attached forms), until they became unattached and drifted downstream (free-floating forms), accumulating in shallow areas of the river. Geosmin in the biofilm ranged from 0.55 +/- 0.97 ng geosmin per mg DW(-1) in the attached biofilms and 5.25 +/- 4.96 ng geosmin per mg DW(-1) in the free-floating biofilms. While the attached mats could be responsible for the local occurrence of geosmin at a given site, the free-floating mats became a relevant agent for the dispersion of the metabolite downstream. This impression was reinforced by the extremely high correlation between the geosmin content in the free-floating biofilm and in the water (r = 0.917, p = 0.00001). In order to reduce the geosmin concentration and accumulation of the cyanobacterial mats in shallow river waters, the nutrient content should be controlled and the natural flow conditions restored, to prevent the growth and accumulation of the geosmin-producing cyanobacterial mats.

Spatial and seasonal variations of water quality in a Mediterranean catchment: the Llobregat River (NE Spain)

The Llobregat and Ter Rivers, typical Mediterranean catchments in Northeast Spain, supply water to more than 4.5 million inhabitants residing in the metropolitan area of Barcelona. The objective of this work is to study the factors that influence the surface water quality of Llobregat catchment. As such, spatial and temporal variations of more 50 water chemical parameters were monitored in 10 sampling sites for a period that extended from July 1996 to December 2000. The temperature, pH and conductivity were measured at sites, whereas metals were analysed using ICP-OES and ICP-MS instrumental techniques. The head waters of the Llobregat River catchment flow through detrital Mesozoic-Cenozoic sedimentary rocks resulting in calcium bicarbonate-type water with low mineral content. The high water quality of the waterhead is deteriorated in the upper-middle part of the catchment due to: occurrence of evaporite-bearing geological formations, and the mining and industrial activities related to potash exploitation. As a result, an obvious increase in Na, K, Mg, Cl-, Br, Rb, and Sr concentrations is reported leading to a sodium (potassium) chloride water type. This saline hydrochemical fingerprint persists downstream. This important feature renders the low water quality of the Llobregat River to be adequate for drinking supply purposes. In addition, the industrial and residential activities, specially at the lower part of the catchment, increases P, B, Mn, Fe, Pb, Al, Cr, Co, Ni, Cu, Zn, As and Sb water concentrations.

Role of superoxide in modulating the renal effects of angiotensin II

Angiotensin II is known to stimulate NADPH oxidase-dependent superoxide (O2-) generation, which may contribute to the acute renal vasoconstrictor and antinatriuretic actions of this peptide. To evaluate this hypothesis, the effects of a superoxide dismutase mimetic (tempol) or a NADPH inhibitor (apocynin) on the angiotensin renal actions were studied. Renal cortical nitric oxide (NO) was measured electrochemically in vivo. Tempol increased sodium excretion and NO levels. Apocynin raised renal blood flow, glomerular filtration rate, sodium excretion, and NO levels. These results indicate the presence of an endogenous NADPH oxidase-dependent O2- generation that may modulate renal function by scavenging NO. Angiotensin II infusion reduced renal blood flow, glomerular filtration, sodium excretion, and NO levels in a dose-dependent manner. The angiotensin receptor antagonist valsartan, tempol, or apocynin blunted the angiotensin effects on renal excretion and NO, suggesting that angiotensin receptors stimulation induces the NADPH oxidase-dependent O2- generation that might reduce NO bioavailability. This idea is supported by the finding that angiotensin increased O2- generation in renal homogenates, and this effect was prevented by valsartan, apocynin, or tempol. These results indicate that some of the acute renal effects of angiotensin II may be enhanced by an increased NADPH oxidase-derived O2- production that reduces renal NO bioavailability.

Oral and vaginal misoprostol 800 microg every 8 h for early abortion

The objective of the study was to evaluate the efficacy and safety of 800 microg misoprostol (Cytotec) every 8 h for 24 h for pharmacological abortion; the treatment was repeated if abortion did not occur in the first 24-h interval. The first misoprostol doses were always self-administered into the vagina; the second and third doses could be administered orally or vaginally depending on the amount of bleeding. Four-hundred and fifty-two women with gestations between 36 and 63 days were recruited into the study. The main outcomes assessed were: successful abortion (complete abortion without surgery), side effects, mean drop in hemoglobin, vaginal bleeding and mean time of return of menstruation. Complete abortion occurred in 409/452 (90.5%; 95% confidence interval [CI] 87%, 93%) patients. Medication to relieve symptoms was administered to all women before the first misoprostol dose. Vaginal bleeding lasted 15.9 +/- 4.4 days. The mean drop in hemoglobin, measured 14 days after abortion, was statistically significant (p = 0.0001) but without clinical relevance. According to the results obtained, 800 microg of misoprostol administered every 8 h for 24 h could be a valid method for abortion for up to 9 weeks of gestation.

Removal and inactivation of indicator bacteriophages in fresh waters

AIMS

The removal and inactivation of faecal coliform (FC) bacteria, enterococci (ENT), sulphite-reducing clostridia (SRC), somatic coliphages, F-specific RNA bacteriophages and bacteriophages infecting Bacteroides fragilis in fresh waters.

METHODS AND RESULTS

Removal was studied in two areas of a river. The results showed different removal of each group of microbes. Faecal coliform bacteria were removed faster than any other, whereas SRC and bacteriophages infecting Bact. fragilis were the most persistent. Inactivation was measured by 'in situ' experiments, which showed significant differences in survival of the different groups of bacterial and bacteriophage indicators. The SRC and bacteriophages were more resistant than faecal coliforms and enterococci, with the exception of F-specific RNA bacteriophages in the summer. Inactivation experiments with pure cultures of bacteriophages confirmed that phage B40-8 of Bact. fragilis was the most resistant.

CONCLUSIONS

Bacteria and bacteriophages show different resistance to natural inactivation. The use of phages allows information to be obtained in addition to that provided by bacterial indicators. Somatic coliphages and phages infecting Bact. fragilis might supply that indicator function.

SIGNIFICANCE AND IMPACT OF THE STUDY

Confirmation was obtained that bacteriophages provided additional information to that provided by bacterial indicators to monitor the natural inactivation of viruses and/or pathogens.

Continuous enantioselective esterification of trans-2-phenyl-1-cyclohexanol using a new Candida rugosa lipase in a packed bed bioreactor

Enantioselective resolution of trans-2-phenyl-1-cyclohexanol (TPCH) by a Candida rugosa lipase, obtained by fermentation in the laboratory, and immobilised on EP100 polypropylene powder has been carried out using isooctane as solvent and propionic acid as esterifying agent. The study have included the utilisation of this biocatalyst in a batch process and the optimisation of the esterification conditions by means of a Box-Hunter-based experimental design. The main variables controlling the process, concentration of acid and alcohol, have been numerically optimised using initial esterification rate as objective function. The optimal concentrations for the batch process were 50 mM for the alcohol and 71 mM for the acid. This esterification reaction kinetics corresponded to a reversible Michaelis-Menten kinetic law for the optimal conditions, which has permitted to select a plug-flow packed bed bioreactor as the most appropriate configuration to minimise the residence time and to avoid shear stress effect on the biocatalyst. The behaviour of the continuous packed bed bioreactor at two different residence times (302 and 582 min) was in accordance with predictions from batch experiments, with slightly deviations (less than 10%). Continuous experiments maintained high values of enantioselectivity (enantiomeric factor was practically 1) and conversion near equilibrium value (35%) when long-time operation was carried out. Besides, long-time stability of biocatalyst has permitted to scale-up the production of enantioenriched (1R,2S)-TPCH propionate to yield gram quantities.

Production of native and recombinant lipases by Candida rugosa: a review

The yeast Candida rugosa produces multiple lipase isoenzymes sharing high sequence homology but with some differences in their catalytic properties. The regulation of C. rugosa lipase (CRL) synthesis and secretion in C. rugosa obeys a complex pattern. Fermentation processes for both wild-type and mutant C. rugosa strains are available for lipase production. Native CRL preparations have been extensively used for biotransformations. However, their inherent mixture of isoforms with variable profiles complicates interpretation and brings into question the reproducibility achieved between preparations. Although heterologous CRLs gene expression had been hampered owing to a nonuniversal codon usage, recent advances have made heterologous CRLs available. This will expand and improve the industrial utility of CRLs even further. The purpose of this review is to provide a summary of the recent advances on the production of native and recombinant lipases by C. rugosa.

Oral versus vaginal misoprostol for cervical priming in first-trimester abortion: a randomized trial

The objective of this study was to compare the oral and vaginal administration of misoprostol for cervical priming before surgical abortion up to 63 days' gestation. A total of 900 pregnant women, with ages ranging from 18 to 42 years, who asked for pregnancy termination, were included in this study. Women were randomly allocated to one of the following groups: oral administration of 400 microg misoprostol, 8 h before aspiration; and vaginal self-administration of 400 microg misoprostol, 4 h before aspiration. During admission, all subjects were checked on a 15-min basis. The preoperative cervical dilatation achieved was the main outcome assessed. The cervix was dilated (Hegar > or = 8) in 348 (78%) subjects from the oral treatment group and in 391 (87%) women from the vaginal treatment group; this difference was statistically significant (p = 0.0004). The mean dilatation achieved in the oral treatment group was 8.1 mm (SD 1.6 mm) and it was 8.5 mm (SD 1.5 mm) in the vaginal treatment group; this difference was statistically significant (p = 0.0001). The frequencies of side-effects such as nausea, vomiting, diarrhea and chills reported by women from the vaginal misoprostol group were 10, 8, 18 and 4 times lower, respectively, than those reported by subjects from the oral misoprostol group. In conclusion, vaginal self-administration of misoprostol was the best administration route, as it obtained the same or greater priming effectiveness of the cervix in half the time with a much lower frequency of side-effects.

N-acetyl-L-cysteine improves renal medullary hypoperfusion in acute renal failure

This study evaluated the effects of N-acetyl-L-cysteine (NAC), a free radical scavenger, and N(omega)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthesis inhibitor, on the changes in renal function, intrarenal blood flow distribution (laser-Doppler flowmetry), and plasma peroxynitrite levels during the acute renal failure (ARF) produced by inferior vena cava occlusion (IVCO; 45 min) in anesthetized rats. Renal blood flow fell on reperfusion (whole kidney by -45.7%; cortex -58.7%, outer medulla -62.8%, and papilla -47.7%); glomerular filtration rate (GRF) also decreased (-68.6%), whereas fractional sodium excretion (FE(Na%)) and peroxynitrite and NO/NO plasma levels increased (189.5, 46.5, and 390%, respectively) after ischemia. Pretreatment with L-NAME (10 microg. kg(-1). min(-1)) aggravated the fall in renal blood flow seen during reperfusion (-60%). Pretreatment with NAC (150 mg/kg bolus + 715 microg. kg(-1). min(-1) iv) partially prevented those changes in renal function (GFR only fell by -29.2%, and FE(Na%) increased 119.4%) and laser-Doppler blood flow, especially in the outer medulla, where blood flow recovered to near control levels during reperfusion. These beneficial effects seen in rats given NAC seem to be dependent on the presence of NO, because they were abolished in rats pretreated with L-NAME. Also, the antioxidant effects of NAC prevented the increase in plasma peroxynitrite after ischemia. In conclusion, NAC ameliorates the renal failure and the outer medullary vasoconstriction induced by ICVO, effects that seem to be dependent on the presence of NO and the scavenging of peroxynitrite.

Optimization of the high-level production of Rhizopus oryzae lipase in Pichia pastoris

The lipases of the Rhizopus species family are important and versatile enzymes that are mainly used in fat and oil modification due to their strong 1,3-regiospecificity. Inexpensive synthetic medium was used for the production of Rhizopus oryzae lipase in the methylotrophic yeast Pichia pastoris. Methanol accumulation inside the bioreactor has previously been shown to negatively influence the production level. Three different methanol fed-batch strategies for maintaining the methanol concentration within optimal limits have been assayed in high-density cultures. One methanol feeding strategy, which is based on the monitoring of the methanol concentration by gas chromatography, resulted in a 2.5-fold higher productivity compared to an initial cultivation, where the feeding rate was adjusted according to the dissolved oxygen concentration (DO) in the supernatant. Finally, productivity could be further increased by introducing a transition phase that involved the simultaneous feeding of glycerol and methanol followed by a single methanol feed. This optimized strategy resulted in the highest productivity (12888 U l(-1) h(-1)), which is 13.6-fold higher than the DO-based strategy.

Misoprostol for abortion at 9-12 weeks' gestation in adolescents

The objectives of the present clinical study were to evaluate the safety and efficacy of misoprostol (Cytotec), self-administered into the vagina for medical abortion, in adolescents under 18 years ofage. A group of 150 adolescents with gestations between 63 and 84 days, with previous written consent from the patient and parents or guardians, received 800 microg of vaginal misoprostol every 24 h, up to a maximum of three main doses, for abortion. Outcomes assessed included successful abortion (complete abortion without surgery), side-effects, decrease in hemoglobin, mean time of vaginal bleeding, mean expulsion time and mean time for the return of menses. Complete abortion occurred in 126/150 (84.0%, 95% confidence interval 77-89) patients. The frequencies of nausea and vomiting were statistically significantly higher when compared to those obtained for adult females. Vaginal bleeding lasted for 13.2 +/- 3.8 days (median 13 days, range 1-22 days). The mean expulsion time was 8.0 +/- 3.4 h (median 8 h, range 1-14 h) for all subjects who aborted after the first misoprostol dose. The mean drop in hemoglobin was statistically significant (p = 0.001), but without clinical relevance. From the high abortion rate obtained, we concluded that misoprostol alone is a valid method for terminating unwanted pregnancies at 10-13 weeks' gestation in adolescents under 18 years of age in the absence of mifepristone.

Vaginal misoprostol 1000 μg for early abortion

The objective of this study was to evaluate the safety and efficacy of 1000 microg misoprostol vaginally (Cytotec) self-administered into the vagina for medical abortion. Three-hundred women with gestations between 42 and 63 days, with previous written consent, received vaginal misoprostol every 24 h up to a maximum of three doses for abortion. Outcome measures assessed included: successful abortion (complete abortion without surgery), side effects, decrease in hemoglobin, mean time of vaginal bleeding, mean expulsion time and mean time of returning of menses. Complete abortion occurred in 279/300 (93.0%, 95% CI 90, 96) patients. Medication to relieve symptoms was administered to all subjects after every misoprostol dose. Vaginal bleeding lasted 14.7 +/- 5.4 days. Mean expulsion time was 8.1 +/- 3.0 h for those who aborted after the first misoprostol dose. The mean drop in hemoglobin was statistically significant (p = 0.0001) but without clinical relevance. The frequencies of nausea and diarrhea were high. According to the observed outcomes, 1000-microg misoprostol vaginally could be a valid method to terminate pregnancies up to nine weeks gestation.

Misoprostol for abortion up to 9 weeks' gestation in adolescents

The objectives of the present clinical study were to evaluate the safety and efficacy of misoprostol (Cytotec) self-administered into the vagina for medical abortion in adolescents under the age of 18 years. After obtaining written consent from the patients and parents or guardians, a group of 150 adolescents with gestations between 35 and 63 days received 800 microg of vaginal misoprostol every 24 h, up to a maximum of three main doses, for abortion. Outcomes assessed included successful abortion (complete abortion without surgery), side-effects, decrease in hemoglobin, mean time of vaginal bleeding, mean expulsion time and mean time for the return of menses. Complete abortion occurred in 133/150 (88.7%, 95% confidence interval 82-93) patients. The frequencies of nausea, vomiting and diarrhea were statistically significantly higher when compared to those obtained for adult females. Vaginal bleeding lasted for 12.7 +/- 5.7 days (median 12 days, range 1-23 days). The mean expulsion time was 6.8 +/- 2.4 h (median 6 h, range 3-14 h) for those who aborted after the first misoprostol dose. The mean time for the return of menses, for those who aborted with misoprostol, was 34.7 +/- 3.4 days. The mean decrease in hemoglobin was statistically significant (p = 0.001), but had no clinical relevance. Taking into account the high abortion rate obtained, we could conclude that misoprostol alone is a valid method for terminating unwanted pregnancies in adolescents under the age of 18 years.

Highly enantioselective esterification of racemic ibuprofen in a packed bed reactor using immobilised Rhizomucor miehei lipase

A systematic study of the enantioselective resolution of ibuprofen by commercial Rhizomucor miehei lipase (Lipozyme(R) IM20) has been carried out using isooctane as solvent and butanol as esterificating agent. The main variables controlling the process (temperature, ibuprofen concentration, ratio butanol:ibuprofen) have been studied using an orthogonal full factorial experimental design, in which the selected objective function was enantioselectivity. This strategy has resulted in a polynomial function that describes the process. By optimizing this function, optimal conditions for carrying out the esterification of racemic ibuprofen have been determined. Under these conditions, enantiomeric excess and total conversion values were 93.8% and 49.9%, respectively, and the enantioselectivity was 113 after 112 h of reaction. These conditions have been considered in the design of a continuous reactor to scale up the process. The esterification of ibuprofen was properly described by pseudo first-order kinetics. Thus, a packed bed reactor operating as a plug-flow reactor (PFR) is the most appropriate in terms of minimizing the residence time compared with a continuous stirred tank reactor (CSTR) to achieve the same final conversion. This reactor shows a similar behavior in terms of enantioselectivity, enantiomeric excess, and conversion when compared with batch reactors. A residence-time distribution (RTD) shows that the flow model is essentially a plug flow with a slight nonsymmetrical axial dispersion (Peclet number = 43), which was also corroborated by the model of CSTR in series. The stability of the system (up to 100 h) and the possibility of reutilization of the enzyme (up to four times) lead to consider this reactor as a suitable configuration for scale up of the process.

Effect of Fermentation Conditions in the Enzymatic Activity and Stereoselectivity of Crude Lipase from Candida rugosa

Different fed-batch cultures of Candida rugosa were carried out using oleic acid as the only carbon source. The crude lipases obtained under several operational conditions and downstream processes showed different catalytic activity and isoenzymes ratio. This fact implied that the performance of the lipase produced could be modulated by using different operational fermentation conditions. These powders were compared with commercial lipase from Sigma (St. Louis, MO) in hydrolysis and synthesis reactions. Especially interesting was the fact that the enantioselectivity of a crude lipase was higher than that observed with commercial lipase in the resolution of racemic Ketoprofen. In addition, response of both lipases in the presence of water was different.

On-line determination of the total lipolytic activity in a four-phase system using a lipase adsorption law

Lipases have a very well known affinity for organic-aqueous interfaces. A previously developed on-line turbidimetric analyser can only analyse the lipase activity present in the aqueous phase of a culture broth. An adsorption law of Langmuir type has been derived to determine the lipolytic activity remaining in the organic-aqueous interface formed between oleic acid and culture broth in Candida rugosa lipase production fermentation. In the concentration range of oleic acid (0-8 g.l(-1)) and lipolytic activity (0-35 U.ml(-1)) tested, lipases were not adsorbed in a multilayer form and the Brunauer-Emmet-Teller (B.E.T.) law was not applicable. The Langmuir adsorption law has been shown to be the most suitable to describe the adsorption process involved. The methodology employed enables on-line determination of the total lipolytic activity produced by the microorganism, using the adsorption law determined. This finding, in combination with the on-line measurement of variables such as biomass, aqueous lipolytic activity, oleic acid concentration and specific growth rate, permits the development of control systems for ensuring improved throughput, quality and repeatability of the process.

Enhancement of Candida rugosa lipase production by using different control fed-batch operational strategies

Simulation studies have predicted that maximum lipase activity is reached with fed-batch operation strategies. In this work, two different fed-batch operational strategies have been studied: constant substrate feeding rate and specific growth rate control. A constant substrate feeding rate strategy showed that maximum aqueous lipolytic activity (55 U/mL) was reached at low substrate feeding rates, whereas lipase tends to accumulate inside the cell at higher rates of substrate addition. In the second fed-batch strategy studied, a feedback control strategy has been developed based on the estimation of state variables (X and mu) from the measurement of indirect variables such as CER by means of mass spectrometry techniques. An on-off controller was then used to maintain the specific growth rate at the desired value by adjusting the substrate feeding rate. A constant specific growth rate strategy gave higher final levels of aqueous lipolytic activity (117 U/mL) at low specific growth rates. At higher specific growth rates the enzyme remained accumulated inside the cell, as was observed with a constant feeding fed-batch strategy. With a constant specific growth rate strategy, lipase production by Candida rugosa was enhanced 10-fold compared to a batch operation. Purification studies have demonstrated that lipolytic and esterasic specific activity ratios of Candida rugosa isoenzymes can be modified by using different operational conditions. These studies have also showed that the isoenzymes obtained in a controlled growth rate strategy are around three- to four-fold more active than those obtained in a constant feeding rate strategy.

Improving lipase production from Candida rugosa by a biochemical engineering approach

It has been tested that the use of oleic acid as sole carbon source and as inducer of the production has an important effect in the lipase production by Candida rugosa under aerobic conditions. A simple structured mathematical model coupled with a methodology to estimate biomass, specific growth rate and substrate was developed and applied to the production of Candida rugosa lipase in batch, fed-batch and continuous operation to obtain a reproducible product. The best operation mode tested was a controlled specific growth rate fed-batch with a 10-fold increase in productivity related to batch operation. Downstream of the culture broth has demonstrated that the ratio between the different isoenzymes presented can be modulated by the selection of the operational strategy and this ratio is quite different comparing with commercial lipases. Thus, their catalytic properties in front of chiral reactions could be different.