Left ventricular assist device (LVAD) program in Chile: first successful experience in South America

Background

The need to have a variety of tools to deal with end-stage heart failure (ES-HF), along with the limited heart transplantation availability encouraged us to create a pilot Left ventricular assist device (LVAD) program in a public health care system hospital in Chile.

Methods

A retrospective analysis of the first nine patients of an ongoing LVAD program initiated on August 2013 was performed, completing an average of 30 months of follow-up. The most important events regarding to morbidity and mortality are described.

Results

Nine patients with ES-HF underwent LVAD implantation surgery; one of them died 23 days after surgery and another died after 11 months. One patient successfully underwent heart transplantation after 16 months of HeartWare ventricular assist device (HVAD) support; the other six patients remain in the program and have an average follow-up of 846 days at the time of this study (range, 23-1,481 days). The survival rate at 6, 12 and 18 months follow-up was 89%, 78% and 78% respectively.

Conclusions

This new pioneering LVAD program in Chile has been successful and now constitutes a vital adjunct to all who work in heart transplantation and ES-HF programs. It offers an effective therapeutic alternative when there is a severe donor shortage, in cases of atypical blood types, emergencies, exceptional cases with contraindication for heart transplantation or when there is important donor-receiver size mismatch.

Thermally Driven Electronic Topological Transition in FeTi

Ab initio molecular dynamics, supported by inelastic neutron scattering and nuclear resonant inelastic x-ray scattering, showed an anomalous thermal softening of the M_{5}^{-} phonon mode in B2-ordered FeTi that could not be explained by phonon-phonon interactions or electron-phonon interactions calculated at low temperatures. A computational investigation showed that the Fermi surface undergoes a novel thermally driven electronic topological transition, in which new features of the Fermi surface arise at elevated temperatures. The thermally induced electronic topological transition causes an increased electronic screening for the atom displacements in the M_{5}^{-} phonon mode and an adiabatic electron-phonon interaction with an unusual temperature dependence.

Successful Visna/maedi control in a highly infected ovine dairy flock using serologic segregation and management strategies

A control system for Visna/maedi virus (VMV) infection based on serologic segregation and management strategies was applied in an infected Spanish dairy Manchega breed sheep flock (n=670) that was affected by a severe respiratory process associated to VMV. The control started in 2004 and consisted on the serological study of animals, segregation in two different flocks (seropositive and seronegative), separate management of flocks, selection of young female lambs for replacement only from seronegative ewes offspring, immediate removal of seropositive animals detected in the seronegative flock and a management tending toward the reduction and final culling of the seropositive flock. The serological control was repeated yearly or twice a year, approximately. Initial VMV seroprevalence of the undivided flock was 66.4% (January 2004) that descended to 47.3%, 12.8%, 2.2% and 0.2% between July 2004 and May 2006. Residual seroprevalence fluctuated slightly thereafter with a peak of 2.2% in April 2008. After segregation, number of animals in the seronegative flock was 378 that descended to 323 in October 2005. Since then, this number has increased steadily reaching 650 sheep in December 2011. The seropositive flock was progressively reduced by culling until its total disappearance in June 2010. This work presents the detailed results obtained in the control strategy against VMV in a single dairy sheep flock by implementing a segregation system based on serologic testing. The system is highly successful, as it reduces to residual levels VMV infection in about two years without the need of culling a high number of animals, as required by other methods. Moreover, the original size flock was been recovered within 8 years and has led to a subjective improvement of animal health and welfare in the flock. The residual seroprevalence could be eliminated at this stage by applying more sensitive molecular or other serological techniques to reach eradication.

Histological and immunohistochemical assessment of liver biopsies in morbidly obese patients

AIMS

To study liver lesions in morbidly obese patients who underwent liver biopsy at the time of bariatric surgery to define histological lesions, especially inflammatory infiltrate, diagnostic categories and the possible influence of gender in this respect.

METHODS AND RESULTS

110 biopsies (36 males-M- and 76 females -F-) were evaluated and categorised, according to the NAS (NAFLD -non alcoholic fatty liver disease- Activity Score) system and other criteria, as non-NAFLD (15.5%, F predominance), non-alcoholic steatohepatitis (NASH) (16.5%, M predominance), non-alcoholic hepatosteatosis (NAHS) (21%, F predominance) and, the most numerous group, NASH-borderline (NASH-BORD) (47%), with three subgroups, characterised by centrozonal lesions, portal area preferential involvement or affecting both areas. The predominant form of hepatocytesteatosis was mixed with a multivesicular component that was present in most cases with fibroinflammatory portal involvement. Nuclear glycogenosomes were found in greater number of biopsies in patients in the third and sixth decades. Portal inflammation was present in a large number of cases (M predominance); the application of immunohistochemical techniques (myeloperoxidase and CD68 antibodies) to evaluate lobular inflammation revealed "surgical hepatitis" in one third of the cases, and the presence of microgranulomas (CD68+) (M predominance), which were more abundant with increasing lesion severity.

CONCLUSIONS

Portal inflammation and multivesicular hepatocytesteatosis are highly prevalent in morbidly obese patients. This study identifies a new subtype of NASH-BORD characterized by centrizonal and porto-periportal area involvement and the existence of liver biopsies without steatosis. CD68+ microgranulomas constitute an unequivocal marker of lobular inflammation in surgical biopsies and of lesion severity, which is gender-related.

Structural relationship between negative thermal expansion and quartic anharmonicity of cubic ScF3

Cubic scandium trifluoride (ScF3) has a large negative thermal expansion over a wide range of temperatures. Inelastic neutron scattering experiments were performed to study the temperature dependence of the lattice dynamics of ScF3 from 7 to 750 K. The measured phonon densities of states show a large anharmonic contribution with a thermal stiffening of modes around 25 meV. Phonon calculations with first-principles methods identified the individual modes in the densities of states, and frozen phonon calculations showed that some of the modes with motions of F atoms transverse to their bond direction behave as quantum quartic oscillators. The quartic potential originates from harmonic interatomic forces in the DO9 structure of ScF3, and accounts for phonon stiffening with the temperature and a significant part of the negative thermal expansion.

Improving anaphylaxis management in a pediatric emergency department

BACKGROUND

The management of anaphylaxis in pediatric emergency units (PEU) is sometimes deficient in terms of diagnosis, treatment, and subsequent follow-up. The aims of this study were to assess the efficiency of an updated protocol to improve medical performance, and to describe the incidence of anaphylaxis and the safety of epinephrine use in a PEU in a tertiary hospital.

METHODS

We performed a before-after comparative study with independent samples through review of the clinical histories of children aged <14 years old diagnosed with anaphylaxis in the PEU according to the criteria of the European Academy of Allergy and Clinical Immunology (EAACI). Two allergists and a pediatrician reviewed the discharge summaries codified according to the International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) as urticaria, acute urticaria, angioedema, angioneurotic edema, unspecified allergy, and anaphylactic shock. Patients were divided into two groups according to the date of implantation of the protocol (2008): group A (2006-2007; the period before the introduction of the protocol) and group B (2008-2009; after the introduction of the protocol). We evaluated the incidence of anaphylaxis, epinephrine administration, prescription of self-injecting epinephrine (SIE), other drugs administered, the percentage of admissions and length of stay in the pediatric emergency observation area (PEOA), referrals to the allergy department, and the safety of epinephrine use.

RESULTS

During the 4 years of the study, 133,591 children were attended in the PEU, 1673 discharge summaries were reviewed, and 64 cases of anaphylaxis were identified. The incidence of anaphylaxis was 4.8 per 10,000 cases/year. After the introduction of the protocol, significant increases were observed in epinephrine administration (27% in group A and 57.6% in group B) (p = 0.012), in prescription of SIE (6.7% in group A and 54.5% in group B) (p = 0.005) and in the number of admissions to the PEOA (p = 0.003) and their duration (p = 0.005). Reductions were observed in the use of corticosteroid monotherapy (29% in group A, 3% in group B) (p = 0.005), and in patients discharged without follow-up instructions (69% in group A, 22% in group B) (p = 0.001). Thirty-three epinephrine doses were administered. Precordial palpitations were observed in one patient.

CONCLUSION

The application of the anaphylaxis protocol substantially improved the physicians' skills to manage this emergency in the PEU. Epinephrine administration showed no significant adverse effects.

Sorption and desorption of Cd, Cu and Pb using biomass from an eutrophized habitat in monometallic and bimetallic systems

This work examines the sorption capacity of a natural biomass collected from an irrigation pond. The biomass mainly consisted of a mixture of chlorophyte algae with caducipholic plants. Biosorption experiments were performed in monometallic and bimetallic solutions containing different metals commonly found in industrial effluents (Cd, Cu and Pb). The biosorption process was slightly slower in the binary system comparing with monometallic system which was related to competition phenomena between metal cations in solution. The biosorbent behaviour was quantified by the sorption isotherms fitting the experimental data to mathematical models. In monometallic systems, the Langmuir model showed a better fit with the following sorption order: Cu ~ Pb > Cd; and biomass-metal affinity order: Pb > Cd ~ Cu. In bimetallic systems, the binary-type Langmuir model was used and the sorption order obtained was: Pb ~ Cu > Cd. In addition, the effectiveness of the biomass was investigated in several sorption-desorption cycles using HCl and NaHCO(3). The recovery of metal was higher with HCl than with NaHCO(3), though the sorption uptake of the biomass was sensitively affected by the former desorption agent in subsequent sorption cycles.

Positive vibrational entropy of chemical ordering in FeV

Inelastic neutron scattering and nuclear resonant inelastic x-ray scattering were used to measure phonon spectra of FeV as a B2 ordered compound and as a bcc solid solution. The two data sets were combined to give an accurate phonon density of states, and the phonon partial densities of states for V and Fe atoms. Contrary to the behavior of ordering alloys studied to date, the phonons in the B2 ordered phase are softer than in the solid solution. Ordering increases the vibrational entropy by +0.22±0.03 kB/atom, which stabilizes the ordered phase to higher temperatures. First-principles calculations show that the number of electronic states at the Fermi level increases upon ordering, enhancing the screening between ions, and reducing the interatomic force constants. The effect of screening is larger at the V atomic sites than at the Fe atomic sites.

Mechanism of adsorption of ferric iron by extracellular polymeric substances (EPS) from a bacterium Acidiphilium sp

The aim of this study was to assess the sorption of Fe(III) by extracellular polymeric substances (EPS) of the Acidiphilium 3.2Sup(5) bacterium, which has promising properties for use in microbial fuel cells (MFC). The EPS of A. 3.2Sup(5) was extracted using EDTA. The sorption isotherms were determined using aliquots of purified EPS. The exosubstances loaded with metal were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopy (FTIR). The sorption uptake approaches to 536.1 +/- 26.6 mg Fe(III) (g EPS)(-1) at an initial ferric concentration of 2.0 g l(-1). The sorption of Fe(III) by EPS can be fitted to the Freundlich model. The sorption process produces hydrated iron (III) oxalate [Fe(OH)(C2O4) x 2H2O] by a reversible reaction (log K = 1.06 +/- 0.16), indicating that a shift in the sorption of the cation can be easily achieved. Know the magnitude and form of iron sorption by EPS in MFC can foresee the potential impact on the metabolism of iron-reducing and iron-oxidazing bacteria and, therefore, on the feasibility of the system.

Bio-reduction of Fe(III) ores using three pure strains of Aeromonas hydrophila, Serratia fonticola and Clostridium celerecrescens and a natural consortium

The present work describes a research approach to the anaerobic bioleaching of Fe(III) ores. Three strains (Serratia fonticola, Aeromonas hydrophila and Clostridium celerecrescens) isolated from an acidic abandoned mine were selected to test their ability to reduce dissimilatory Fe(III). Total iron bio-reduction was achieved after 48 h using either the consortium or the Aeromonas cultures. In the latter case, there was no evidence of precipitates and Fe(II) remained in solution at neutral pH through complex formation with citrate. None of the other cultures tested (mixed culture and the two isolates) exhibited this behaviour. Biotechnologically, this is a very promising result since it obviates the problem associated with undesirable precipitation of iron compounds in Fe(III)-reducing bacterial cultures. The performance of the Aeromonas culture was improved progressively by adaptation to moderately acidic pH values (up to 4.5) and to three different Fe(III)-oxyhydroxides as the sole source of iron: ferrihydrite, hematite and jarosite, commonly found as weathering compounds at mine sites. Dissimilatory Fe(III)-reducers for iron extraction from ores is therefore especially attractive in that acidification of the surrounding area can be minimized.

Studies on sorption, desorption, regeneration and reuse of sugar-beet pectin gels for heavy metal removal

This work reports the effectiveness of sugar-beet pectin xerogels for the removal of heavy metals (cadmium, lead and copper) after multiple batch sorption-desorption cycles, with and without a gels regeneration step. Metals were recovered from xerogel beads without destroying their sorption capability and the beads were successfully reused (nine cycles) without significant loss in both biosorption capacity and biosorbent mass. Metals uptake levelled off or increased after using a 1M CaCl(2) regeneration step after each desorption. Calcium, as a regenerating agent, increased the stability and reusability of the gels repairing the damage caused by the acid and removing the excess protons after each elution providing new binding sites. Because of their excellent reusability, pectin xerogels are suitable for metal remediation technologies.

Minimum handling method for the analysis of phosphorous inhibitors of urolithiasis (pyrophosphate and phytic acid) in urine by SPE-ICP techniques

Pyrophosphate (PPi) and phytic acid (IP6) are natural phosphorous compounds with growing interest in the biomedical field due to their ability as potential inhibitors of urolithiasis among others. Existing methodologies for their evaluation show inconveniences mainly associated with sample treatment, matrix interferences and lack of resolution. The objective of the present work is the validation of a new method to determine both inhibitors in urine samples selectively and its application to the diagnosis of lithiasic patients. After urine purification by an off-line anion exchange solid phase extraction (SPE), based in an appropriate acidic elution gradient, the phosphorous compounds were analyzed by (31)P measurements by inductively coupled plasma mass spectrometry (ICP-MS) in the purified urine extracts. Linear range and limit of detection obtained were adequate for the analysis of the physiological amounts of the compounds in urine. The method was successfully applied to human urine samples, resulting in adequate accuracy and precision and allowing for the analysis of phosphorus inhibitors of urolithiasis in urine. The method simplicity and high sample throughput leads to a clear alternative to current determinations of the mentioned species in urine. Moreover, PPi and IP6 concentrations found in patients suffering from oxalocalcic urolithiasic were significantly lower than those for healthy controls, supporting the fact that the risk for oxalocalcic urolithiasis increases when urinary phosphorus inhibitors decrease. Thus, speciation of phosphorus inhibitors of urolithiasis in urine of stone formers can be performed, which is of unquestionable value in diagnostic, treatment and monitoring of urolithiasis.

Gold(III) biosorption and bioreduction with the brown alga Fucus vesiculosus

In this paper, the bioreduction of Au(III) to Au(0) using biomass of the brown alga Fucus vesiculosus was investigated. The recovery and reduction process took place in two stages with an optimum pH range of 4-9 with a maximum uptake obtained at pH 7. In the first stage, an induction period previous to gold reduction, the variation of pH, redox potential and gold concentration in solution was practically negligible and no color change was observed. In the second stage, the gold reduction was followed by a sharp decrease of gold concentration, pH and redox potential of solution and a color change from yellow to reddish purple. Hydroxyl groups present in the algal polysaccharides were involved in the gold bioreduction. Metallic gold was detected as microprecipitates on the biomass surface and in colloidal form as nanoparticles in the solution. Bioreduction with F. vesiculosus could be an alternative and environmentally friendly process that can be used for recovering gold from dilute hydrometallurgical solutions and leachates of electronic scraps, and for the synthesis of gold nanoparticles of different size and shape.

Markers that predict serious bacterial infection in infants under 3 months of age presenting with fever of unknown origin

OBJECTIVE

To evaluate potential markers of serious bacterial infection (SBI) in infants under 3 months of age presenting with fever of unknown origin.

MATERIAL AND METHODS

We retrospectively studied all infants under 3 months of age seen in the emergency department between January 2004 and December 2006 for a febrile syndrome with no identifiable focus. Clinical data, procalcitonin (PCT), C reactive protein (CRP) and leucocyte count were evaluated for their ability to discriminate between SBI and non-SBI; receiver operating characteristic (ROC) curves were constructed for the laboratory markers and analysis was performed by multivariate logistic regression.

RESULTS

The sample comprised 347 patients (23.63% with SBI). Mean PCT, CRP, leucocyte and neutrophil count were significantly higher in the group with SBI unlike the other criteria studied. The area under the ROC curve (AUC) for PCT was 0.77 (95% CI 0.72 to 0.81) and 0.79 for CRP (95% CI 0.75 to 0.84); both these variables were stronger predictors than leucocyte count (0.67, 95% CI 0.63 to 0.73). In the 15 infants with more invasive bacterial infections (sepsis, bacteraemia, bacterial meningitis), the diagnostic value of PCT (AUC 0.84, 95% CI 0.79 to 0.88) was higher than CRP (AUC 0.68, 95% CI 0.63 to 0.73). In infants who had been febrile for under 12 h, the differences between PCT, CRP and leucocyte count were statistically significant in both SBI and non-SBI groups, with increasing predictive value of PCT and decreasing value of CRP.

CONCLUSIONS

PCT, CRP, and leucocyte count have intrinsic predictive value for SBI in febrile infants under 3 months of age. The diagnostic value of PCT is greater than CRP for more invasive bacterial infections and for fever of short duration.

Pressure-Induced Invar Behavior in Pd3Fe

Synchrotron x-ray diffraction (XRD) measurements, nuclear forward scattering (NFS) measurements, and density functional theory (DFT) calculations were performed on L1_{2}-ordered Pd3Fe. Measurements were performed at 300 K at pressures up to 33 GPa, and at 7 GPa at temperatures up to 650 K. The NFS revealed a collapse of the 57Fe magnetic moment between 8.9 and 12.3 GPa at 300 K, coinciding with a transition in bulk modulus found by XRD. Heating the sample under a pressure of 7 GPa showed negligible thermal expansion from 300 to 523 K, demonstrating Invar behavior. Zero-temperature DFT calculations identified a ferromagnetic ground state and showed several antiferromagnetic states had comparable energies at pressures above 20 GPa.

Biosorption of cadmium, lead and copper with calcium alginate xerogels and immobilized Fucus vesiculosus

This paper determines the effect of immobilized brown alga Fucus vesiculosus in the biosorption of heavy metals with alginate xerogels. Immobilization increased the kinetic uptakes and intraparticle diffusion rates of the three metals. The Langmuir maximum biosorption capacity increased twofold for cadmium, 10 times for lead, and decreased by half for copper. According to this model, the affinity of the metals for the biomass was as follows: Cu>Pb>Cd without alga and Pb>Cu>Cd with alga. FITR confirmed that carboxyl groups were the main groups involved in the metal uptake. Calcium in the gels was displaced by heavy metals from solution according to the "egg-box" model. The restructured gel matrix became more uniform and organized as shown by scanning electron microscopy (SEM) characterization. F. vesiculosus immobilized in alginate xerogels constitutes an excellent biosorbent for cadmium, lead and copper, sometimes surpassing the biosorption performance of alginate alone and even the free alga.

Optimization of the continuous biosorption of copper with sugar-beet pectin gels

Sugar-beet pectin xerogels obtained from residues of the sugar industry are an adequate material for metal recovery from effluents in continuous systems. The xerogels were used as a biosorbent for copper removal in a fixed-bed column. The performance of the system was evaluated in different experimental conditions: flow rate, bed height, inlet metal concentration and feeding system (drop and reverse). The effect on the biosorption parameters (saturation time, amount of adsorbed and treated metal, column performance and metal uptake) and the shape of the breakthrough curves was determined. The saturation time increased with increasing bed height but decreased with increasing feed flow rate and inlet metal concentration. Preferential flow channels greatly influenced the metal uptake and column performance. Copper was completely desorbed with 0.1M HNO(3). Additionally, the column data fitted both the linear and nonlinear expressions of the Thomas model.

Extraction of extracellular polymeric substances from the acidophilic bacterium Acidiphilium 3.2Sup(5)

Extraction of extracellular polymeric substances (EPS) from Acidiphilium 3.2Sup(5) was investigated using five methods: EDTA, NaOH, ion exchange resin, heating and centrifugation. The bacterium studied presents promising application in microbial fuel cells (MFCs). The degree of cellular lysis provoked by each method was determined by UV-visible spectroscopy of cultures before and after EPS extraction. In addition, two electron microscopy techniques (TEM and SEM) were employed to determine the degree of attachment and the growth of the biofilm overtime on two solid supports: carbon fibre cloth and graphite rods. The main constituents of the EPS extracted by all methods were proteins and carbohydrates, as confirmed by FT-IR analysis, showing the major presence of carboxylic, hydroxylic and amino groups. The greater extractions of EPS were obtained using EDTA. This method also produced a less degree of cellular lysis. Furthermore, both the amount and the chemical composition of EPS strongly depended on the extraction method used.

Study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method

The biosorption of several metals (Cd2+, Zn2+ and Pb2+) by orange wastes has been investigated in binary systems. Multicomponent sorption isotherms were obtained using an original procedure, similar to that proposed by Pagnanelli et al. [Pagnanelli, F., Petrangeli, M.P., Toro, L., Trifoni, M., Veglio, F., 2001a. Biosorption of metal ions on Arthrobacter sp.: biomass characterization and biosorption modelling. Environ. Sci. Technol. 34, 2773-2778] for monoelement systems, known as subsequent addition method (SAM). Experimental sorption data were analysed using an extended multicomponent Langmuir equation. The maximum sorption uptake was approximately 0.25mmol/g for the three binary systems studied. The reliability of the proposed procedure for obtaining the equilibrium data in binary systems was verified by means of a statistical F-test.

Characterization of the biosorption of cadmium, lead and copper with the brown alga Fucus vesiculosus

The recovery of cadmium, lead and copper with the brown alga Fucus vesiculosus was characterized and quantified. The biosorption data fitted the pseudo-second order and Langmuir isotherm models, but did not adjust to the intraparticle diffusion model. The metal uptakes deduced from the pseudo-second order kinetic model and the Langmuir isotherm model followed a similar sequence: Cu>Cd approximately Pb. The Langmuir maximum metal uptakes were: 0.9626 mmol/g, Pb 1.02 mmol/g, and Cu 1.66 mmol/g. According to the equilibrium constants of this isotherm model, the affinity of metals for the biomass followed this order: Pb>Cu>Cd. Biosorption was accomplished by ion exchange between metals in solution and algal protons, calcium and other light metals, and by complexation of the adsorbed metals with algal carboxyl groups. FTIR spectra showed a shift in the bands of carboxyl, hydroxyl and sulfonate groups.

Biosorption with Algae: A Statistical Review

The state of the art in the field of biosorption using algae as biomass is reviewed. The available data of maximum sorption uptake (qmax) and biomass-metal affinity (b) for Cd2 +, Cu2 +, Ni2 +, Pb2 + and Zn2 + were statistically analyzed using 37 different algae (20 brown algae, 9 red algae and 8 green algae). Metal biosorption research with algae has used mainly brown algae in pursuit of treatments, which improve its sorption uptake. The information available in connection with multimetallic systems is very poor. Values of qmax were close to 1 mmol/g for copper and lead and smaller for the other metals. Metal recovery performance was worse for nickel and zinc, but the number of samples for zinc was very small. All the metals except lead present a similar affinity for brown algae. The difference in the behavior of lead may be due to a different uptake mechanism. Brown algae stand out as very good biosorbents of heavy metals. The best performer for metal biosorption is lead.

Adiabatic electron-phonon interaction and high-temperature thermodynamics of A15 compounds

Inelastic neutron scattering was used to measure the phonon densities of states of the A15 compounds V3Si, V3Ge, and V3Co at temperatures from 10 to 1,273 K. It was found that phonons in V3Si and V3Ge, which are superconducting at low temperatures, exhibit an anomalous stiffening with increasing temperature, whereas phonons in V3Co have a normal softening behavior. First-principles calculations show that this anomalous increase in phonon frequencies at high temperatures originates with an adiabatic electron-phonon coupling mechanism. The anomaly is caused by the thermally induced broadening of sharp peaks in the electronic density of states of V3Si and V3Ge, which tends to decrease the electronic density at the Fermi level. These results show that the adiabatic electron-phonon coupling can influence the phonon thermodynamics at temperatures exceeding 1,000 K.

Biosorption of heavy metals by Fucus spiralis

The sorption uptake of cadmium, nickel, zinc, copper and lead by marine brown alga Fucus spiralis was investigated in bimetallic, trimetallic and multimetallic solutions. The experimental data fitted very well to Langmuir model. In bimetallic systems, the affinity of biomass for lead and copper increased and the sorption uptake of these metals was not affected by increasing concentrations of cadmium, nickel or zinc. However, in solutions with both metals there was a significant mutual decrease of their sorption levels at high concentrations of the other metal. The sorption uptake of cadmium, nickel and copper was investigated in trimetallic aqueous systems. Based on the kinetic parameter b, the affinity of F. spiralis for copper was considerably higher than for cadmium or nickel: bCd=6.39, bNi=1.82 and bCu=17.89. In all tests, the maximum sorption uptake remained practically constant around 1 mmol/g, indicating that the number of active sites on the biomass was limited. Tests with four and five metals showed that copper was preferentially adsorbed. The differences between the experimental sorption data and those given by the chemical speciation program PHREEQCI were negligible. In general, the software used provided satisfactory estimated data for each metal and hence can be a useful tool to predict or simulate the real process.

Comparative study of biosorption of heavy metals using different types of algae

Sorption capacity of six different algae (green, red and brown) was evaluated in the recovery of cadmium, nickel, zinc, copper and lead from aqueous solutions. The optimum sorption conditions were studied for each monometallic system. The optimum pH was 6 for the recovery of Cd, Ni and Zn, and less than 5 for Cu and Pb. The best results were obtained with the lowest biomass concentration used (0.5 g/L). Experimental data fitted a Langmuir model very well according to the following sequence of the sorption values: Pb>Cd> or =Cu>Zn>Ni. The brown algae achieved the lowest metal concentration levels in solution; the best results were obtained with Fucus spiralis. Finally, a software computer program was used to simulate the process by comparison of theoretical with experimental results and show minimum differences between both types of data.

Biosorption of heavy metals by activated sludge and their desorption characteristics

The biosorption of different metals (Cu2+, Cd2+, Zn2+, Ni2+ and Pb2+) was investigated using activated sludge. The optimum pH was 4 for Cd, Cu and Pb sorption and 5 for Ni and Zn. Biomass metal uptake clearly competed with protons present in the aqueous medium, making pH an important variable in the process. Protons consumed by biomass in control tests versus protons exchange in biosorption tests confirmed a maximum exchange between metal cations and protons at pH 2. The study of the influence of biomass concentration revealed that the amount of protons released from biomass increased with biomass concentration. This would confirm the hypothesis of ion exchange between both types of ions. The application of the Langmuir and Freundlich models showed a better fitting of experimental data to the first model. The maximum sorption uptake of the studied metals by the activated sludge showed the following decreasing order: Pb>Cu>CdZn>Ni. Desorption experiments showed that HCl was a good eluent for the five metals tested, particularly at low pH values (1 and 2). At pH 3 or 4 the desorption yield was significantly lower. However, its use did not allow the reuse of biomass in subsequent loading and unloading cycles. EDTA was also a good desorption agent, achieving the total recovery for the five metals tested at a concentration of 1mM, with the advantage that biomass could be reused for three sorption-desorption cycles.

Influence of Concomitant Food Intake on the Excretion of Orally Administeredmyo-Inositol Hexaphosphate in Humans

myo-Inositol hexaphosphate (InsP6) widely occurs in plant seeds. At present, some important benefits of InsP6 for human health have been described. The purpose of this study was to find the best condition for the optimum absorption of orally administered InsP6, evaluated by InsP6 urinary excretion. The influence of different stomach conditions (empty, empty with an alkalinizing agent, and full stomach) on the effects of oral administration of InsP6 and its urinary excretion was investigated in six healthy subjects on an InsP6-poor diet, given 400 mg of calcium/magnesium salt of InsP6 as a single dose. The basal urinary excretion of InsP6 on an InsP6-poor diet (50.91 +/- 15.09 microg) was significantly lower than that found when an InsP6-normal diet was consumed (100.09 +/- 26.42 microg) (P < .05). No differences were observed in the areas under the curve of accumulated excretion at 8 hours among the three different stomach conditions studied, suggesting that the overall InsP6 absorption took place independently of the stomach state (full or fasted) and indicating that the InsP6 absorption also takes place during the intestinal transit. Thus, if InsP6 supplements of vegetal origin are consumed to maintain the optimum InsP6 levels needed for a healthy status, these supplements can be consumed either during or between meals with the same efficacy.

Gold and silver uptake and nanoprecipitation on calcium alginate beads

Calcium alginate beads were investigated for their biosorption performance in the removal of gold and silver from aqueous solutions. It was found that uptake capacities were significantly affected by the solution pH, with optimum pH values of 2 and 4 for gold and silver, respectively. Kinetic and isotherm experiments were carried out at the optimum pH. The maximum uptake capacities were 290 mg/g for Au and 52 mg/g for Ag. FTIR analysis indicated that both carboxylic and hydroxylic functional groups in alginate beads are involved in the metal binding and later reduction of gold (+3) and silver (+1) to gold (0) and silver (0). SEM and X-ray diffraction confirmed the formation of gold and silver nanoparticles.

Effects of trace metals on the inhibition of calcium oxalate crystallization

The aim of this study was to examine the possible effects of some trace metals on the inhibition of calcium oxalate crystallization. A test of urinary lithogenic risk was used to follow the crystallization of calcium oxalate from artificial urine in the presence of several metal ions assayed in their physiological concentrations. Interactions of these metal ions with known inhibitors of such crystallization (phytate, pyrophosphate, citrate and chondroitin sulphate) were also investigated. None of the metals affected the inhibition of calcium oxalate crystallization at concentrations approximating those found in normal urine, with the exception of the Fe3+ ions. Interactions of Fe3+ with some urinary components produced both synergic (phytate and pyrophosphate) and negative (citrate) effects on preventing crystallization. These effects are explained in terms of the affinity of the inhibitors for the calcium oxalate crystal surface and their ability to form stable complexes in urine. Because of the minimal concentrations, we conclude that physiological concentrations of trace elements in urine have no significant influence on calcium oxalate crystallization. In this sense, ferric ions, which exhibit an intrinsic high inhibitory capacity of calcium oxalate crystallization at physiological concentrations, even increased by the concomitant presence of phytate and pyrophosphate, are probably unable to act as powerful inhibitors in the presence of physiological urinary concentrations of citrate, due to the formation of highly stable complexes in solution without inhibitory activity.

[Metabolic imaging by positron emission tomography using [18F] fluorodeoxiglucose in developmental disorders]

INTRODUCTION

Developmental disorders are a common pathological condition in Neuropaediatrics and do not usually present characteristic anatomical alterations in the different neuroanatomical imaging tests that can be employed, such as computerised axial tomography or magnetic resonance (MR). Positron emission tomography (PET) using [18F] fluorodeoxiglucose (PET FDG), one of the battery of imaging tests currently available, enables us to obtain data about brain activity in a non invasive manner.

PATIENTS AND METHODS

A group of 39 patients with developmental disorders from the Hospital del Mar was analysed. They were submitted to PET FDG brain metabolism tests and in some cases hybrid PET MR images were also obtained; findings were then correlated against the clinical progression of the patients.

RESULTS AND CONCLUSIONS

The alterations that were observed showed predominantly bilateral thalamic, mesial temporal and orbital frontal hypometabolism. This alteration of the limbic system, which has no correlation with anatomical damage, can be a predictor of the clinical progression and of the confirmation of the presence of alterations in the brain functions in this type of patients.

Determination of Phytic Acid in Urine by Inductively Coupled Plasma Mass Spectrometry

An ICPMS method for the determination of phytic acid in human urine based on the total phosphorus measurement of purified extracts of phytic acid is described. Pretreatment of the sample is required to avoid interference in the ICPMS detection from other phosphorus compounds accompanying phytic acid in urine such as phosphate or pyrophosphate. This treatment consists of a simple filtration of the urine sample followed by complete separation of phytic acid from the mentioned phosphorus components using an anion-exchange solid-phase extraction. Separation/recovery conditions, optimized for standards of phytic acid prepared in water and artificial urine, were successfully applied to natural urine samples, resulting in adequate accuracy and precision. Linear range (0.02-0.6 mg of phytic acid L(-)(1)) and limit of detection (5 microg L(-)(1) phytic acid) are adequate for analysis of the usual amounts of phytic acid present in urine. Phosphate, pyrophosphate, and pH of urine samples at concentrations exceeding their normal physiological ranges do not affect the determination of phytic acid. Because of the simplicity, low sample requirement, and relatively high sample throughput (10 to 6 min per sample for runs between 50 and 100 samples, respectively), the present method presents the best alternative to current methods for phytic acid determination in urine. Results also show that the method is adequate for the differentiation of levels of phytic acid excretion from patients suffering from oxalocalcic urolithiasis and healthy controls, suggesting that low phytic acid concentrations in urine lead to elevated risk of oxalocalcic urolithiasis.

Health information on the Internet: accessibility, quality, and readability in English and Spanish

CONTEXT

Despite the substantial amount of health-related information available on the Internet, little is known about the accessibility, quality, and reading grade level of that health information.

OBJECTIVE

To evaluate health information on breast cancer, depression, obesity, and childhood asthma available through English- and Spanish-language search engines and Web sites.

DESIGN AND SETTING

Three unique studies were performed from July 2000 through December 2000. Accessibility of 14 search engines was assessed using a structured search experiment. Quality of 25 health Web sites and content provided by 1 search engine was evaluated by 34 physicians using structured implicit review (interrater reliability >0.90). The reading grade level of text selected for structured implicit review was established using the Fry Readability Graph method.

MAIN OUTCOME MEASURES

For the accessibility study, proportion of links leading to relevant content; for quality, coverage and accuracy of key clinical elements; and grade level reading formulas.

RESULTS

Less than one quarter of the search engine's first pages of links led to relevant content (20% of English and 12% of Spanish). On average, 45% of the clinical elements on English- and 22% on Spanish-language Web sites were more than minimally covered and completely accurate and 24% of the clinical elements on English- and 53% on Spanish-language Web sites were not covered at all. All English and 86% of Spanish Web sites required high school level or greater reading ability.

CONCLUSION

Accessing health information using search engines and simple search terms is not efficient. Coverage of key information on English- and Spanish-language Web sites is poor and inconsistent, although the accuracy of the information provided is generally good. High reading levels are required to comprehend Web-based health information.

Comparative study on the selective chalcopyrite bioleaching of a molybdenite concentrate with mesophilic and thermophilic bacteria

This study evaluates different bioleaching treatments of a molybdenite concentrate using mesophilic and thermophilic bacterial cultures. Further studies on the chemical leaching and the electrochemical behavior of the MoS(2) concentrate were carried out. Bioleaching tests showed a progressive removal of chalcopyrite from the molybdenite concentrate with an increase in temperature. Chemical leaching tests support the idea of an indirect attack of the concentrate. Electrochemical tests indicate that chalcopyrite dissolution is favored when molybdenite is present. Therefore, this type of bioleaching treatment could be applied to purify molybdenite flotation concentrates by selectively dissolving chalcopyrite.

Growth of moderately halophilic bacteria isolated from sea water using phenol as the sole carbon source

Moderately halophilic bacteria utilizing phenol as the sole carbon source were isolated by selective enrichment from sea water. The isolate (Gram-negative motile rods) was identified as Deleya venusta. It grew well in the presence of up to 1600 mg/L of phenol and 8% NaCl under aerobic conditions. When the cells were treated with chloramphenicol prior to the addition of phenol they did not utilize added phenol, even after prolonged incubation. Thus, the enzymes necessary for phenol metabolism appeared to be inducible.

Effect of electron beam irradiation on color and microbial bioburden of red paprika

The effect of irradiation with electron beams on the microbiological quality and color properties of red paprika was examined. The irradiation doses ranged from 0 to 12.5 kGy. The counts performed were total mesophilic aerobic microorganisms, Enterobacteriaceae, coliforms, sulfite-reducing clostridia, molds, and yeasts. It was concluded that molds, yeasts, and sulfite-reducing clostridia were the most resistant species, although a 10-kGy dose of irradiation leads to optimum sanitation. Extractable color and apparent color were analyzed to appraise the incidence of the irradiation treatments in the color properties of red paprika. Extractable color was determined according to the American Spice Trade Association method, and apparent color was analyzed by reflectance using the CIELab color space. Data showed no significant differences between the color properties of irradiated and nonirradiated samples. Irradiation was a suitable procedure to minimize the bioburden of red paprika with small modifications of its color properties.

Photoacoustic determination of the luminescent quantum efficiency of yb(3+) ions in lithium niobate

The luminescent quantum efficiency of Yb(3+) ions in lithium niobate (LiNbO(3)) is obtained by use of a method based on the simultaneous and multiwavelength measurement of photoacoustic and luminescent signals after modulated continuous laser excitation. The experimental results give a high value for the luminescence quantum efficiency (? = 0.90 ? 0.05), coincident with the predictions by the comparison between experimental and estimated radiative lifetimes.

Effect of cationic micelles on the formation of the complex oxalate-Alizarin Red S-Zr(IV) Application to the sensitive fluorescence determination of oxalate ion

The effect of several surfactants on the formation of the fluorescent ternary complex oxalate-Alizarin Red S-zirconium(IV) has been studied. In weakly acidic medium and in the presence of cationic surfactants, such as cetylpyridinium chloride, total complex formation is achieved, whereas in aqueous medium or in the presence of non-cationic micelles no significant changes are obtained in comparison with the formation of the non-fluorescent binary complex Alizarin Red S-zirconium(IV). The fluorescence characteristics of this system allowed the establishment of a simple and very sensitive method for the spectrofluorimetric determination of oxalate. The ternary complex formed exhibits its highest fluorescence signal at 605 nm with excitation at 490 nm. In these conditions, the method presents a IUPAC detection limit of 4.4 ng ml(-1). The procedure has been satisfactorily applied to a biological fluid and a vegetal tissue.

MsPG3, a Medicago sativa polygalacturonase gene expressed during the alfalfa-Rhizobium meliloti interaction

Polygalacturonase (PG) is one of the most important enzymes associated with plant cell wall degradation. It has been proposed to participate in the early steps of the Rhizobium-legume interaction. We have identified two classes of cDNA fragments corresponding to two classes of PG genes in the Medicago genome. One of this class, represented by E2 in M. truncatula and Pl1 in M. sativa, seems to be related to previously characterized plant PG genes expressed in pollen. We have isolated the genomic clone containing the entire gene corresponding to the second class (E3). We showed that MsPG3 is a single gene in the Medicago genome coding for PG. By reverse transcription-PCR, MsPG3 expression was detected in roots 1 day after Rhizobium inoculation. The early induction of the MsPG3, as also seen by in situ hybridization experiments, supports its involvement in the early stages of the Rhizobium-legume infection process. In addition, by analyzing the expression of a MsPG3 promoter-gus construct in Vicia hirsuta-transgenic root nodules, we showed that MsPG3 was expressed in all cells of nodule primordia and in the cells of the invasion zone. By Northern blot, MsPG3 transcripts are not detected in various Medicago tissues, indicating that the function of this gene is related closely to symbiosis. Thus, our results strongly suggest the involvement of MsPG3 gene during meristem formation and/or in the infection process, probably by facilitating cell wall rearrangement, penetration of the bacteria through the root hair wall, or infection thread formation and release of bacteria in plant cells. MsPG3 represents a class of PG genes, distinct from the pollen-specific genes, and it is the first pectic encoded enzyme demonstrated to be involved in Rhizobium-legume symbiosis.

Red blood cell phenotypes in alpha-thalassemias in the Spanish population

BACKGROUND AND OBJECTIVE

alpha-thalassemia is very common on all thalassemic geographical regions. The present work aimed at analyzing the relationship between the degree of microcytosis and hematological parameters and the type of alpha-thalassemic mutation.

DESIGN AND METHODS

Five hundred and thirty-six subjects with 4 kinds of alpha-thalassemia were examined using established techniques that determined all hematological parameters, and globin synthesis and molecular biological techniques to study the DNA of globin genes by Southern blotting.

RESULTS

Adult carriers of alpha (+)-thalassemia (-alpha/alpha alpha) present very few hematological alterations. In a statistical comparison with normal individuals (alpha alpha/alpha alpha), significant differences were found between the hemocytometric data and the MCV and MCH of heterozygous alpha + thalassemia and the heterozygous alpha zero or homozygous alpha + genotype. Hb H disease was detected in 15 patients, presenting a severe degree of anemia, a significant increase in RDW and globin chain synthesis with an alpha/beta ratio of 0.5 +/- 0.1.

INTERPRETATION AND CONCLUSIONS

These data provide reference values for geographical areas where alpha + thalassemia is common. These hematocytometric data, together with hemoglobin analysis, could be useful as a future reference data for new patients diagnosed with alpha-thalassemia.

[Iron deficiency and pica]

PURPOSE

To study the relationship between pica and iron-lack anaemia in a series of iron-deficiency patients in order to establish the pathogenesis of such relationship.

PATIENTS AND METHODS

Four-hundred and thirty-three patients were analysed. Pica was studied by introducing certain diet queries into the clinical history. All patients received oral iron and were periodically controlled with the usual clinico-haematological procedures.

RESULTS

Pica was present in 23 patients (5.3%). Eight nourishing (namely, coffee grains, almonds, chocolate, ice, lettuce, carrots, sunflower seeds and bread) and 2 non-nourishing (clay and paper) substances were involved. A second episode of pica appeared in 9 cases upon relapsing of iron deficiency. Both anaemia and pica were cured by etiologic and substitutive therapy in all instances. No clear correlation was found with either socio-economic status or pathogenetic causes of iron deficiency and pica, and no haematological differences were seen between patients with pica and those without this alteration.

CONCLUSIONS

(1) The pathogenesis of pica is unclear, although it appears unrelated to the degree of iron deficiency. (2) According to the findings in this series, pica seems a consequence of iron deficiency rather than its cause. (3) Adequate therapy can cure both conditions, although pica may reappear upon relapse of iron deficiency.

[Association of alpha and beta thalassemia with alpha gene triplication in one family]

We describe the haematological data and molecular results of a native family from Cádiz in that one is produced the a within heterozygous beta 0 thalassaemia (IVS-1, nt 1-G-->A), heterozygous alpha+ thalassaemia (-alpha 3.7) and alpha gene triplication (alpha alpha alpha 3.7). PATIENTS AND METHODS) We are studied 7 members to a family composed by father (I1), mother (I2) and five children (II1, II2, II3, II4, II5). The molecular biology study of the alpha gene was realized by Southern blot method using the restriction enzymes Bam HI, Bgl II and Eco RI and hybridized with alpha probe of the plasmid PRB 1 (fragment of 1.5 Kb digested with the enzyme Pst I). The genes were studied by the technique of the polymerase chain reaction (PCR), modified according to designated method "Amplification Refractory Mutation System" (ARMS).

RESULTS

The father (I1) presents an interaction of therozygous beta 0 thalassaemia with heterozygous alpha + thalassaemia (beta 0/beta 1;alpha alpha/-alpha 3). The mother (I2) shows an alpha gene triplication (beta A/beta A: alpha alpha alpha 3.7/alpha alpha). Finally the children are expressed 5 possibilities: II4 he is normal (beta A/beta A; alpha alpha/alpha alpha), II2 he has alpha gene triplication (beta A/beta A; alpha alpha/alpha alpha alpha 3.7), II3 he has heterozygous beta 0 thalassaemia (beta 0/beta A; alpha alpha/alpha alpha), II5 he has interaction between heterozygous beta 0 thalassaemia and heterozygous alpha gene triplication (beta 0/beta A; alpha alpha alpha 3.7/alpha alpha) and II1 presents an interaction between a heterozygous beta 0 thalassaemia and together with the lost of one alpha gene in one chromosome he also presents a alpha gene triplication in other one (beta o/beta A; alpha alpha/alpha alpha). The hematological data of II5 corresponds to a intermediate thalassemia with not transfusion dependent feature an opposite to II1 that presents a heterozygous thalassemic trait features with 4 alpha genes.

DISCUSSION

The phenotypical expression of the different interactions of these mutations in this family, points out, the relevant role that the unbalance globins chains plays in the pathogenesis and development of the clinical manifestations of the patients with the thalassaemia syndromes.

[Effects of several methods of thoracic drainage on respiratory function]

The object of this study was to verify the influence on the pulmonary function of the pleural space ampliation with pleural drainage tube underwater seal, with several volumes or with variables negative pressures. We performed 42 New Zealand white rabbits of both sexes with an average age of 57 +/- 9.31 days and an average weight of 1720 +/- 181 g. The experimental protocol consisted of study group: P1 (n = 14) was performed a unilateral thoracostomy at the 5th. Intercostal space and P2 (n = 14) with bilateral pleural drainage. The pleural drainage tube (drain trocart ORX Vygon number 8) connected at small bottle (Fp), with 35 ml of extrapleural volume and at big bottle (FG) with 3940 ml of extrapleural volume and vacuum suction of various negative pressures (-5, -10, -15 and -20 cm H2O).

CONTROL GROUP

C1 (n = 7) with unilateral pleural drainage clamped and C2 (n = 7) with bilateral pleural drainage clamped. Anesthesia was induced with ketamine hydrochloride (7.5 ml/Kg) and propionilpromazyne (1.5 ml/Kg) intramuscular cocktail and after maintained with bolus injection of 1/4 induction dose. We studied the mortality, the the fluctuations of drain hydrostatic column, heart rate (FC), respiratory rate (FR) and blood gas tensions, after cannulation of right jugular vein and during the different phases of experimental design. Venous blood samples were obtained for pO2, pCO2 and pH measurements were repeated at 5' in both groups. The 50% of animals died in the P2 group during the drainage pleural of FG. The fluctuation of column of Fp was similar in both groups: P1 = 6.39 +/- 1.0, with a decrease of 0.64 +/- 0.23 and P2 = 6.37 +/- 1.29, with a decrease of 0.63 +/- 0.28, respectively. The vacuum suction of pleural cavity may produce a FR fall which recovery fast. The bilateral pleural drainage with negative pressures produced decreases of pCO2 and pO2. There is not modifications of Acid Base Balance in the experimental groups. We concluded that during bilateral pleural underwater seal connected a FG, because the increase of extrapleural space may produce a high mortality and a fall of respiratory rate with fast recovery. Also the pleural suction improved the CO2 diffusion into the alveolus. There is not modifications of pO2 in P1 group or decrease in the P2 group.