Chemometric-assisted method development in reversed-phase liquid chromatography.

The computer-assisted development of separation procedures in liquid chromatography (LC), which has involved the adaptation of diverse chemometric techniques and the incorporation of successive advances in informatics and computing over a period of more than four decades, has provided chromatographers with commercial and academic tools of great utility. These tools enable the development, optimization (including robustness studies) and transfer of procedures that constitute one of the analytical activities most commonly used at present in laboratories and industries worldwide. Departing from a typical operational scheme of manually developed chromatographic procedures, this review describes some of the different tools and options that chemometrics provides to the chromatographer for the computer-assisted approach, and outlines the present status of this approach and possible reasons why it is still not considered fully satisfactory.

Determination of artificial sweeteners in water samples by solid-phase extraction and liquid chromatography-tandem mass spectrometry.

The development and performance evaluation of an analytical method for the determination of six artificial sweeteners in environmental waters using solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry are presented. To this end, different SPE alternatives have been evaluated: polymeric reversed-phase (Oasis HLB, Env+, Plexa and Strata X), and mixed-mode with either weak (Oasis WAX) or strong anionic-exchange (Oasis MAX and Plexa PAX) sorbents. Among them, reversed-phase sorbents, particularly Oasis HLB and Strata X, showed the best performance.

Antiplasmodial effect of the venom of Crotalus durissus cumanensis, crotoxin complex and Crotoxin B.

The antiplasmodial activity of phospholipases A(2) (PLA(2)) isolated from different animals has been studied. We explored the in vitro anti Plasmodium falciparum effect of a fraction containing crotoxin, Crotoxin B and whole venom of the rattlesnake Crotalus durissus cumanensis. Fraction II (crotoxin complex) was obtained by size exclusion chromatography, whereas Crotoxin B was purified by RP-HPLC.

Validity and reliability of the Spanish version of the Involvement Evaluation Questionnaire among caregivers of patients with eating disorders.

The Involvement Evaluation Questionnaire (IEQ) was developed to evaluate burden among caregivers of patients with schizophrenia. We aimed to examine its psychometric properties among caregivers of patients with eating disorders (ED). A prospective study was carried out, recruiting caregivers of patients with an ED attending two outpatient clinics in Bizkaia, Spain.

Cell death triggered by synthetic flavonoids in human leukemia cells is amplified by the inhibition of extracellular signal-regulated kinase signaling.

A new class of methyl esters of flavonoids, with different substituents on the B ring were synthesized and evaluated for their antiproliferative activity against the human leukemia cell line HL-60. The presence of either a methyl group (1f) or a chlorine atom (1o) at position 2' of the B ring played an important role in affecting antiproliferative activity. The cytotoxic effects of these compounds were accompanied by the concentration- and time-dependent appearance of DNA- and nuclear-fragmentation, increase in the percentage of sub-G(1) cells, and processing of multiple caspases and poly(ADP-ribose)polymerase cleavage.

Ion-pair sorptive extraction of perfluorinated compounds from water with low-cost polymeric materials: polyethersulfone vs polydimethylsiloxane.

A method for the determination of seven perfluorinated carboxylic acids and perfluorooctane sulphonate (PFOS) in aqueous samples using low-cost polymeric sorptive extraction as sample preparation technique, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination has been developed and validated. Simplicity of the analytical procedure, low volume of solvent and sample required, low global price and a good selectivity providing cleaner extracts are the main advantages of this extraction technique. Polydimethylsiloxane (PDMS) and polyethersulfone (PES) materials were evaluated and compared to achieve the best extraction efficiencies.

Comparing illicit drug use in 19 European cities through sewage analysis.

The analysis of sewage for urinary biomarkers of illicit drugs is a promising and complementary approach for estimating the use of these substances in the general population. For the first time, this approach was simultaneously applied in 19 European cities, making it possible to directly compare illicit drug loads in Europe over a 1-week period. An inter-laboratory comparison study was performed to evaluate the analytical performance of the participating laboratories.

Effectiveness of pandemic and seasonal influenza vaccines in preventing pandemic influenza-associated hospitalization.

Vaccines are leading pharmacological measures for limiting the impact of pandemic influenza in the community. The objective of this study was to investigate the effectiveness of influenza (pandemic and seasonal) vaccines in preventing pandemic influenza-associated hospitalization. We conducted a multicenter matched case-control study in 36 Spanish hospitals.

Impact of clinical and patient-reported outcomes on patient satisfaction with cataract extraction.

Background: To date, factors that influence satisfaction with cataract surgery have not been broadly explored.

Objective: To identify variables related to patient satisfaction after cataract extraction by phacoemulsification and to determine the relationship between satisfaction and visual acuity (VA) and visual function (VF).

Design: Prospective cohort study.

Burden of caregiving amongst family caregivers of patients with eating disorders.

Background: Eating disorders (EDs) in a close relative can be particularly stressful for family members.

Aims: To assess the perceived burden of caregivers of patients with EDs and to identify demographic and clinical variables that could predict this burden.

Method: We conducted a cross-sectional study involving 145 ED patients and 246 related caregivers.

Iliac bone Candida albicans osteomyelitis in a patient with iliac crest bone autograft: a case report and review of the literature.

Candida osteomyelitis is a well recognized but infrequent entity. We describe an interesting case of iliac bone C. albicans osteomyelitis as a result of a surgical trauma of an iliac bone for the auto-grafting of a fracture in the lumbar spine.

Etiology of community-acquired pneumonia in a population-based study: link between etiology and patients characteristics, process-of-care, clinical evolution and outcomes.

Background: The etiologic profile of community-acquired pneumonia (CAP) for each age group could be similar among inpatients and outpatients. This fact brings up the link between etiology of CAP and its clinical evolution and outcome. Furthermore, the majority of pneumonia etiologic studies are based on hospitalized patients, whereas there have been no recent population-based studies encompassing both inpatients and outpatients.

Determination of Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in water samples by solid-phase microextraction with on-fiber derivatization and gas chromatography-mass spectrometry.

A new method for the determination of two cannabinoids, Δ9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH), in wastewater samples is proposed using solid-phase microextraction (SPME) as extraction technique and gas chromatography coupled to mass spectrometry (GC-MS) as determination technique. Several parameters involved in SPME extraction were studied and optimized (time, temperature, volume, pH and ionic strength of sample, and type of fiber). Moreover two derivatization reagents, N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), were studied in depth, providing MSTFA the best results.

Gas chromatography/mass spectrometry comprehensive analysis of organophosphorus, brominated flame retardants, by-products and formulation intermediates in water.

A multiresidue method based on gas chromatography coupled to quadrupole mass spectrometry was developed to determine organophosphorus flame retardants, polybromodiphenyl ethers (BDEs 28, 47, 99, 100, 153, 154, 183 and 209), new brominated flame retardants, bromophenols, bromoanilines, bromotoluenes and bromoanisoles in water. Two ionization techniques (electron ionization--EI, and electron capture negative ionization--ECNI) and two acquisition modes (selected ion monitoring--SIM, and selected reaction monitoring--SRM) were compared as regards to mass spectral characterization, sensitivity and quantification capabilities. The highest sensitivity, at expenses of identification capacity, was obtained by GC-ECNI-MS/SIM for most of the compounds analyzed, mainly for PBDEs and decabromodiphenyl ethane while GC-EI-MS/MS in SRM was the most selective technique and permitted the identification of target compounds at the pg level, and identification capabilities increased when real samples were analyzed.

Effectiveness of hand hygiene and provision of information in preventing influenza cases requiring hospitalization.

Background: The objective of the study was to investigate the effectiveness of non-pharmacological interventions in preventing cases of influenza requiring hospitalization.

Methods: We performed a multicenter case-control study in 36 hospitals, in 2010 in Spain. Hospitalized influenza cases confirmed by reverse-transcription polymerase chain reaction and three matched controls (two hospital and one community control) per case were selected.

Synthetic menthyl α/β-(1→6)-diglucopyranosides-induced cell death in human leukemia cells is dependent on caspases.

A series of alkyl α/β-(1→6)-diglucopyranosides 1-12 were synthesized and assessed for cytotoxicity against HL-60, U937, Molt-3 and MCF-7 cancer cell lines. The menthyl derivatives displayed strong cytotoxic properties showing IC(50) values between 6 and 16 μM. Furthermore, we demonstrated that the selected synthetic (+)-menthyl β-(1→6)-diglucopyranoside 5 induces apoptotic cell death in human leukemia cells through a mechanism that involves activation of multiple caspases.

Boron neutron capture therapy (BNCT) for liver metastasis: therapeutic efficacy in an experimental model.

Boron neutron capture therapy (BNCT) was proposed for untreatable colorectal liver metastases. The present study evaluates tumor control and potential radiotoxicity of BNCT in an experimental model of liver metastasis. BDIX rats were inoculated with syngeneic colon cancer cells DHD/K12/TRb.

Score to identify the severity of adult patients with influenza A (H1N1) 2009 virus infection at hospital admission.

The objective of this paper was to develop a prognostic index for severe complications among hospitalized patients with influenza A (H1N1) 2009 virus infection. We conducted a prospective observational cohort study of 618 inpatients with 2009 H1N1 virus infection admitted to 36 Spanish hospitals between July 2009 and February 2010. Risk factors evaluated included host-related factors and clinical data at admission.

Prognosis of hospitalized patients with 2009 H1N1 influenza in Spain: influence of neuraminidase inhibitors.

Background: The H1N1 influenza pandemic strain has been associated with a poor prognosis in hospitalized patients. The present report evaluates the factors influencing prognosis.

Methods: A total of 813 patients hospitalized with H1N1 influenza in 36 hospitals (nationwide) in Spain were analysed.

Risk factors and effectiveness of preventive measures against influenza in the community.

Background: The role of different risk exposures and preventive measures against influenza has not been well established.

Objective: The aim of this study was to evaluate risk factors and measures to prevent influenza infection in the community.

Methods: We conducted a multicenter case-control study.

2009 H1N1: risk factors for hospitalization in a matched case-control study.

In order to compare sociodemographical data and preexisting risk medical conditions in patients requiring hospital admission for 2009 pandemic influenza A (H1N1) virus infection and those managed on an outpatient basis, a prospective observational, matched case-control study in 36 hospitals of the Spanish National Health Service was conducted from July 2009 to February 2010. Cases were patients aged 6 months to 18 years hospitalized for influenza syndrome, in whom 2009 influenza A (H1N1) virus infection was confirmed using real-time reverse-transcription polymerase chain reaction. Controls were patients aged 6 months to 18 years with confirmed 2009 influenza A (H1N1) infection managed on an outpatient basis.

Sociodemographic factors and clinical conditions associated to hospitalization in influenza A (H1N1) 2009 virus infected patients in Spain, 2009-2010.

The emergence and pandemic spread of a new strain of influenza A (H1N1) virus in 2009 resulted in a serious alarm in clinical and public health services all over the world. One distinguishing feature of this new influenza pandemic was the different profile of hospitalized patients compared to those from traditional seasonal influenza infections. Our goal was to analyze sociodemographic and clinical factors associated to hospitalization following infection by influenza A(H1N1) virus.

Predictors of change in perceived burden among caregivers of patients with eating disorders.

Background: Little is known about whether the perceived burden of caring for someone with an eating disorder (ED) changes over time or what may predict such change.

Methods: In this prospective study of ED patients and their caregivers, caregivers answered the Involvement Evaluation Questionnaire - EU Version (IEQ-EU), the Hospital Anxiety and Depression Scale (HADS), the SF-12, and the Anorectic Behaviour Observation Scale (ABOS) at baseline and after one and two years of follow-up. On the same schedule, patients answered the HADS and the SF-12, as well as the Eating Attitudes Test (EAT-26) and the Health-Related Quality of Life in ED - short form (HeRQoLED-s).

Transformation of phenazone-type drugs during chlorination.

Chlorination is one of the most popular disinfection steps for water treatment in Europe. However, chlorine can react with pharmaceuticals and other micropollutants leading to either their elimination or by-products being formed. These by-products are frequently not identified and therefore the consequences of chlorination can be underestimated.

A plastic miniature x-ray emission spectrometer based on the cylindrical von Hamos geometry.

We present a short working distance miniature x-ray emission spectrometer (miniXES) based on the cylindrical von Hamos geometry. We describe the general design principles for the spectrometer and detail a specific implementation that covers Kβ and valence level emission from Fe. Large spatial and angular access to the sample region provides compatibility with environmental chambers, microprobe, and pump/probe measurements.