Evaluation of the dispersion properties of graphene oxide/cetyltrimethylammonium bromide for application in nanocomposite materials

The properties of thermal diffusivity and Z potential of the GONPs/CTAB nanofluid were studied as a function of GO concentration (in the range between 4 and 12% w/v), temperature (35 and 50 °C) and time (30 and 60 min) under ultrasound. In turn, the structural properties of GONPs/CTAB were measured by XRD, Raman, SEM and TEM. The GO previously modified with CTAB was used to obtain a PLA/GO nanocomposite. It was found that the behavior of thermal diffusivity provides information in situ on the dispersion properties of the nanofluid, finding values from 0.0013 to 0.0024 cm2 s-1. The hydrodynamic diameter of the GONP dispersions was also determined to range from 75.83 to 360.3 nm with an increase in Z potential from 17 to 30 mV. The most stable GONPs/CTAB dispersion conditions were 6% w/v GO, 50 °C and 30 min. Under these conditions, the GONPs/CTAB materials present an increase in the spacing between GO layers, associated with a greater multilayer stacking of the GO and CTAB layers. The Raman spectrum allowed us to demonstrate that the modification with CTAB did not affect the crystallinity of GO, which was verified by the intensity ratio of the D band and the G band (ID/IG) for the GO/CTAB samples, with the exception of the GO 6% sample, where an increase in the ID/IG ratio (0.9) was observed compared to GO (0.82), associated with greater intercalation of CTAB between the GO sheets. Finally, an SEM analysis of the PLA/GO nanocomposite was carried out and the homogeneous distribution of GO in PLA was demonstrated when it is used as a filler in proportions of 0.1%. This treatment, in turn, contributed to improving the mechanical flexural properties of the nanocomposite materials.

Elizabethkingia miricola: an opportunistic pathogen in ICU

Background

The Elizabethkingia genus is formed by a group of bacteria which are widely distributed in nature. Elizabethkingia is not part of human microbiota, therefore is considered to be an opportunistic pathogen. In the last years, it has become a cause of potentially fatal disease, becoming an emerging bacteria of increasing relevance. The objective of this study is to describe the impact of Elizabethkingia bacteria in infected patients in the ICU of a hospital in Granada.

Methods

Descriptive study. Patients who have been isolated in a biological sample of Elizabethkingia miricola throughout the year 2.021 in the ICU of San Cecilio University Hospital in Granada. Date and place of isolation were registered. Other variables registered were sex, age, length of ICU stay, days between ICU admission and bacterium isolation, days between bacterium isolation and death, infection, cause of admission or cause of death.

Results

Bacterium was isolated in 15 patients. Cause of admission was COVID-19 in 73.3% of patients. 73.3% were men and 26.6% women.The average age was 56.9 years. The average length of ICU stay was 43.8 days. 4 patients were diagnosed with ventilator-associated pneumonia and 5 patients were diagnosed with tracheobronchitis.The average days between ICU admission and bacterium isolation was 26,4 days. The average days between mechanical ventilation and bacterium isolation was 25.9 days. 53.3% of patients died. The average days between bacteria isolation and death was 18.2 days.

Conclusions

Elizabethkingia miricola is an emerging bacterium under special vigilance due to its capacity to cause major morbidity and mortality in admitted patients in ICU. The rapid identification and the study of the antibiotic susceptibility is considered of special relevance so they can be correctly managed to avoid infections and complications resulting from this microorganism.

Key messages

• Elizabethkingia is a special surveillance bacterie due to its morbidity and mortality effects.

• Elizabethkingia could be a severity indicator in admitted patients to the ICU.

Physical characteristics of nano-Hydroxyapatite Pickering-emulsions and their adjuvant activity on the antibody response towards the Bothros asper snake venom

Emulsions are crucial in the treatment of snake bites to bust the antibody response of the inmunogen. The widely used Freund's emulsion typically combines 50/50 water-oil (W/O) phase. However, its use is limited because it is associated with tissue damage. We formulated and characterized a Pickering Emulsion 70/30 (W/O) that uses a chemically modified hydrophobic hydroxyapatite as surfactant. This Pickering emulsion has similar rheologic behavior to Freund's emulsion 50/50, but with lower oil and surfactant concentration. Evaluation of cell recruitment, antibody response and adhering tissue in mice immunized with B. asper of Pacific venom and treated with Freund's and Pickering 70/30 emulsions resulted in similar adjuvant activity (only 18% lower in Pickering 70/30 emulsion). However, Pickering 70/30 emulsions minimized negative side effects in the host animals and showed better ease of flow that favors injection of the host. Our results open up room for optimization and improvement of Pickering emulsion based on modified nanoparticles for medical applications.

Application of thermal lens microscopy (TLM) for measurement of Cr(VI) traces in wastewater

In this work, we demonstrate for the first time that Thermal Lens Microscopy technique (TLM) can be applied to monitor the dynamics of a photocatalytic process in-situ. The photocatalytic reduction of hexavalent chromium -Cr(VI)- in aqueous solution using CdS and irradiated with visible light is monitored by TLM. Since the values of Cr(VI) concentration obtained after the photocatalytic process were close to those imposed by the international regulations for drinking water, the use of TLM allowed its measurement with a better reliability than with UV spectroscopy, usually used in this kind of analysis.

Thermal diffusivity measurement in thin metallic filaments using the mirage method with multiple probe beams and a digital camera

Photothermal beam deflection is a well-established technique for measuring thermal diffusivity. In this technique, a pump laser beam generates temperature variations on the surface of the sample to be studied. These variations transfer heat to the surrounding medium, which may be air or any other fluid. The medium in turn experiences a change in the refractive index, which will be proportional to the temperature field on the sample surface when the distance to this surface is small. A probe laser beam will suffer a deflection due to the refractive index periodical changes, which is usually monitored by means of a quadrant photodetector or a similar device aided by lock-in amplification. A linear relationship that arises in this technique is that given by the phase lag of the thermal wave as a function of the distance to a punctual heat source when unidimensional heat diffusion can be guaranteed. This relationship is useful in the calculation of the sample's thermal diffusivity, which can be obtained straightforwardly by the so-called slope method, if the pump beam modulation frequency is well-known. The measurement procedure requires the experimenter to displace the probe beam at a given distance from the heat source, measure the phase lag at that offset, and repeat this for as many points as desired. This process can be quite lengthy in dependence of the number points. In this paper, we propose a detection scheme, which overcomes this limitation and simplifies the experimental setup using a digital camera that substitutes all detection hardware utilizing motion detection techniques and software digital signal lock-in post-processing. In this work, the method is demonstrated using thin metallic filaments as samples.

Note: Photopyroelectric measurement of thermal effusivity of transparent liquids by a method free of fitting procedures

In a recent paper published in this journal [R. Ivanov et al., Rev. Sci. Instrum. 86, 064902 (2015)], a methodology free of fitting procedures for determining the thermal effusivity of liquids using the electropyroelectric technique was reported. Here the same measurement principle is extended to the well-known photopyroelectric technique. The theoretical basis and experimental basis of the method are presented and its usefulness is demonstrated with measurements on test samples.

A method for thermal diffusivity measurement in fluids

A technique is proposed for thermal diffusivity measurement in fluids. It is based on the Angstrom method, but with excitation of thermal waves by electromagnetic energy absorption and pyroelectric detection. The good agreement between measured thermal diffusivity of air and some test liquids with literature values shows the validity of the method. It is free of some limitations of conventional photopyroelectric technique with length scanning because it is free of moving parts inside the sample and because it avoids problems associated with the non-parallelism between thermal wave generator surface and sensor. It does not require any data normalization procedure or special sample preparation.

An alternative differential method of femtosecond pump-probe examination of materials

We describe an alternative method for femtosecond pump-probe beam examination of energy transport properties of materials. All already reported techniques have several drawbacks which limit precise measurements of reflection coefficient as function of time. A typical problem is present when rough samples are being studied. In this case the pump-beam polarization changes randomly which may produce a spurious signal, drastically reducing the signal to noise ratio. Some proposals to alleviate such problem have been reported, however, they have not been totally satisfactory. The method presented here consists on measuring the difference between the two delays' signals of the probe-beam. As will be explained, our proposal is free of typical drawbacks. We also propose a numerical method to recover the ΔR(t)/R curve from the measured data. Numerical simulations show that our proposal is a viable alternative.

Haematological values of post-laying Arrau turtle (Podocnemis expansa) in the Orinoco River, Venezuela

The Arrau turtle (Podocnemis expansa) is an endangered species, as a result of long-lasting, unsustainable exploitation. To obtain reference haematological values from the wild Podocnemis expansa during post-laying, 20 turtles were captured in the Orinoco River. Blood was obtained from the dorsal cervical sinus in lithium heparin tubes. Red blood cells (RBC), white blood cells (WBC), thrombocytes (TC), packed cell volume (PCV), plasmatic protein (PP), haemoglobin (Hgb), mean corpuscular volume (MCV) and differential leukocyte count were determined. Haematological values were: RBC 0.9×10(9)/L, WBC 5.7×10(9)/L, TC 5.4×10(9)/L, PCV 35.6%, PP 4.2g/dL, Hgb 11.8g/dL, MCV 411fL. The differential leukocyte count comprised: 71% heterophils, 23% lymphocytes, 3% eosinophils, 1.6% basophils, and 1% monocytes. The reports of reference haematology values for the wild P. expansa are limited; therefore, the results presented herein contrast with those values obtained in captivity. This study represents a contribution to the referential haematological values of the wild P. expansa.

Thermal characterization of ZnO-DMSO (dimethyl sulfoxide) colloidal dispersions using the inverse photopyroelectric technique

Nanofluids, i.e., colloidal dispersions of nanoparticles in a base liquid (solvent), have received considerable attention in the last years due to their potential applications. One attractive feature of these systems is that their thermal conductivity can exceed the corresponding values of the base fluid and of the fluid with large particles of the same chemical composition. However, there is a lack of agreement between published results and the suggested mechanisms which explain the thermal conductivity enhancement. Here we show the possibilities of the inverse photopyroelectric method for the determination of the effective thermal effusivity of the system constituted by small ZnO nanoparticles dispersed in dimethyl sulfoxide, as a function of the nanoparticles volumetric fraction. Using a phenomenological model we estimated the thermal conductivity of these colloidal samples without observing any significant enhancement of this parameter above effective medium predictions.

Photo-induced charge transfer in Prussian blue analogues as detected by photoacoustic spectroscopy

The photo-induced charge transfer in four series of Prussian blue (PB) analogues was studied from photoacoustic spectra. In cobalticyanides the observed signals were assigned to a metal-to-ligand charge transfer, which appears as a shoulder below 450 nm, and to d-d transitions for Co(II), Ni(II) and Cu(II) complex salts. No evidence of metal-to-metal charge transfer was observed for this series, which is probably due to the high stability of low spin cobalt(III) in the hexacyanide complex. Photoacoustic spectra for ferricyanides are broad bands, which result particularly intense up to 750 nm. Such features were attributed to the overlapping of contributions from metal-to-ligand (<600 nm) and metal-to-metal charge transfer transitions, with probably also a minor contribution from d-d transitions in the outer metal. The spectra for the ferrocyanides series are dominated by the metal-to-ligand charge transfer band below 550 nm, approximately 100 nm above this transition in cobalticyanides. Within the studied solids, the most intense and broad metal-to-metal charge transfer bands were found for a series of low spin Co(III) high spin Co(II) hexacyanoferrates(II,III) and with similar features also for ferric ferrocyanide (Prussian blue), assigned to Fe(II)-->Co(III) and Fe(II)-->Fe(III) photo-induced transition, respectively. The first of these transitions requires of more energetic photons to be observed, its maximum falls at 580 nm while for Prussian blue it is found at 670 nm. Prussian blue analogues are usually obtained as nanometric size particles and many of them have a microporous structure. The role of surface atoms on the observed charge transfer bands in the studied series of compounds is also discussed.

Activity of taraxasteryl acetate on inflammation and heat shock protein synthesis

Pluchea sagittalis whole plant dichloromethane extract showed inhibitory activity in several inflammatory models: rat hind paw-edema, mice ear edema, and air-pouch rat granuloma. The extract inhibited the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in stimulated human neutrophils. It also showed inhibitory effect on heat shock protein 72 (hsp72) synthesis in stimulated neutrophils, while it had opposite effects on unstimulated cells. The triterpene taraxasteryl acetate was obtained from the dichloromethane extract by bioassay directed isolation, being active against induced ROS and RNS production in human neutrophils. In mice ear edema (induced by phorbol-12-mirystate-13-acetate, croton oil and arachidonic acid), taraxasteryl acetate showed a topical anti-inflammatory activity similar to the extract, but at 1/20 of the dose. The same ratio was observed for the inhibition of hsp72 production in stimulated human neutrophils. In unstimulated monocytes and neutrophils, taraxasteryl acetate showed a higher stimulating activity of hsp72 production than the extract, involving different mechanisms in each cell type. To our knowledge, taraxasteryl acetate is the first natural product for which a dual effect on the hsp response is reported.

Septic arthritis due to Streptococcus bovis in a patient with cirrhosis of enolic etiology

We present a case of bacteremia and septic arthritis due to Streptococcus bovis biotype I after shock, in a patient with liver cirrhosis of enolic etiology. Diagnosis was made based on a clinical setting of fever and a painful shoulder. The presence of colonic neoplasia was ruled out in this patient and the bacteremia developed without endocarditis.

Photoacoustic determination of iron in corn meal

We report here on the use of the photoacoustic technique for the determination of low concentrations of total iron in corn meal samples. The determination of this element in food is of considerable interest because several foods are currently enriched with it at proper levels in order to increase the resistance of people, after consumation, to several diseases, such as anemia. The proposed technique is based on an open photoacoustic cell configuration in conjunction with a suitable colorimetric method. We applied it to a measurement of the total iron concentration in corn meal samples. The results agree very well with those obtained using a conventional spectrophotometric method, showing the possibilities of new experimental methodologies based on photothermal methods to perform this kind of study, with the advantage of a higher sensitivity and increment of the range of appreciable absorbance.

The evolution of the pH in Europe (1986-1997) using panel data

The temporal evolution of pH values in precipitation over Europe during the period 1986-1997 is examined using panel data. The use of panel data techniques allows us to determine the temporal evolution of groups of stations rather than analyzing the temporal behavior of each of them. The analysis reveals three different temporal patterns: Peripheral, Central and French. We find a significant increasing trend (P < 0.00001) in both Peripheral and Central patterns. The annual increases are +0.057 pH-units yr(-1) and +0.022 pH-units yr(-1) respectively. However the French pattern is characterized by a significant decreasing trend (P < 0.004) and the annual decrease is -0.022 pH-units yr(-1). The standard errors of panel data estimates are around 47% smaller than those of classical pooling and 32% smaller than aggregate time-series regression. The use of panel data produces higher R2 values than classical pooling and aggregate data. This technique takes into account the individual heterogeneity, allows a larger number of data points and improves the efficiency of the estimates. In general, the policies of governments to reduce pollutant emissions seem to be effective.

Multivariate space analysis of the major precipitation ions over Europe, 1986-1997

The annual average concentrations (1986-1997) of the major ions SO4(2-), NO3-, Cl-, NH4+, Na+, Mg2+, Ca2+, and K+ in precipitation are analyzed for selected EMEP stations. The objective is to determine the ion patterns or typologies in precipitation by principal component analysis (PCA) combined with a cluster analysis. SO4(2-) and NO3- ions are predominant in central and eastern Europe. This area corresponds to high emissions of SO2 and NO2. Sea spray ions are predominant in coastal sites. The soil components show an important contribution in southern Europe, possibly due to the soil dust transported from northern Africa.

How effective has been the reduction of SO2 emissions on the effect of acid rain on ecosystems?

The paper attempts to assess the effectiveness of the reduction of SO2 emissions over recent years for protection of ecosystems in both Europe and eastern USA by analysis of temporal changes in the acidifying potential (AP) of wet deposition defined as [SO4(2-)] - ([Ca2+] + [Mg2+]). Spatial and temporal patterns of acidifying potential were studied. The main result is that there is no statistical evidence for a trend towards improvement in the acidifying potential, because there have been declines in Ca precipitation. This suggests that the reduction of SO2 emissions has not been effective as an abatement strategy.

Activity of plant extracts on the respiratory burst and the stress protein synthesis

Aqueous, methanol and dichloromethane extracts from Artemisia copa, Baccharis grisebachii, Baccharis incarum, Baccharis latifolia, Mutisia kurtzii and Pluchea sagittalis, plants used in the Traditional Medicine of South America, are studied for activity on the respiratory burst and the inducible heat shock protein of 72 kD (hsp72) synthesis. Activity on the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), as well as on hsp72 synthesis was measured by flow cytometry in human neutrophils. Cells were stimulated using hydrogen peroxide, phorbol-12-myristate-13-acetate (PMA) or formyl-methionyl-leucyl-phenylalanine (FMLP) for ROS generation, and sodium nitroprusside (SNP) or PMA in the presence of calmodulin inhibitor W-13 for RNS. The production of hsp72 was induced by heat, PMA, H2O2 and SNP. The best inhibitory activity was shown by the dichloromethane extracts of Baccharis grisebachii and Pluchea sagittalis that were active in all the assays. The aqueous extract of Pluchea sagittalis was also active in most assays. The aqueous extract from Mutisia kurtzii caused a clear increase of the hsp72 production and showed prooxidant activity.

Mechanisms involved in the hemodynamic alterations in congestive heart failure as a basis for a rational pharmacological treatment

Congestive heart failure is a complex syndrome and one of the major cardiological problems of our time. It is characterized by an important neurohumoral activation to compensate for the reduction of cardiac output and blood pressure, that worsens the prognosis with time. The aim of the treatment is focused on how to improve the quality of life and how to prolong survival. Usually, treatment, either symptomatic or directed to control the neuroendocrine compensatory changes, is necessary. The drugs currently used are angiotensin-converting enzyme inhibitors, diuretics, digoxin, and beta-adrenoceptor agonists. In addition, new drugs, such as angiotensin II receptor antagonists, beta-adrenoceptor antagonists, ibopamine, Ca(2+) antagonists, neutral endopeptidase inhibitors, vasopressin antagonists, Ca(2+)-sensitizers with cyclic AMP-dependent or -independent mechanisms, and endothelin antagonists, are also being used.

[Guidelines of the Spanish Society of Cardiology for clinical practice in exercise testing]

Most exercise testing is performed in adults with known or suspected ischemic heart disease. In the last few years cardiac imaging techniques have been applied in this field, improving the information obtained with the procedure. However, the exceptions to this rule are emerging rapidly not only in healthy people (asymptomatic individuals, athletes, handicapped people) but also in cardiac patients (advanced congestive heart failure, hypertension, rhythm disorders, congenital heart disease, etc.). All the-se issues justify the need for a multidisciplinary consensus document in Spain. This paper reviews and updates the methodological aspects of the stress test, including those related to oxygen consumption measurements. The main aim of this review was to determine the role of exercise testing in the evaluation of ischemic heart disease as well as the applications of imaging stress testing. The usefulness of this test in other non-ischemic cardiac disorders and in selected subsets of healthy people is also reviewed.

Changes in plasma oxidative state with age and their influence on contractions elicited by noradrenaline in the rat tail artery

The present study analyzes the changes in plasma oxidative state with age and their influence on the contractions induced by noradrenaline (NA) in endothelium-denuded segments from the tail artery of 6- (young), 24- (old) and 30- (very old) month-old Sprague Dawley rats. The sensitivity (-log EC50) to NA increased with age, this increase being higher in old than in very old animals. Moreover, the maximum response (Emax) to NA did not change in old rats, whereas decreased in very old animals. We also found a progressive increase in the plasma oxidative state with age, measured as malondialdehyde (MDA) levels, that was accompanied by a decrease in the plasma antioxidative state, measured as glutathione peroxidase activity. In addition, MDA (0.5, 1 and 10 microM) potentiated the NA responses in 6-, 24- and 30-month-old rats, respectively, without affecting Emax. In young animals, catalase (1000 U/ml) or dimethylsulfoxide (7 mM), scavengers of hydrogen peroxide or hydroxyl radicals, respectively, did not modify either the contractions induced by NA in control situation or the potentiation of these responses caused by MDA. However, the superoxide anion scavenger, superoxide dismutase (SOD, 150 U/ml), completely reversed the increase in sensitivity to NA caused by MDA, without affecting NA responses in control situation. These results suggest that the increase in NA sensitivity with age could be due, at least in part, to the enhancement of plasma oxidative state during aging. In addition, in this alteration of the responses to NA caused by MDA, the generation of superoxide anions appears to be involved. This study supports the hypothesis that the enhancement of plasma oxidative state could play an important role in the increase of vascular resistance with age.

Anti-inflammatory action of Pluchea sagittalis: involvement of an antioxidant mechanism

Pluchea sagittalis, (Lam.) Cabr., a popular medicinal herb grown in South America, was studied for anti-inflammatory and antioxidant activities. The anti-edema action of P. sagittalis aqueous extract was assayed in different models of inflammation: 1) the mouse ear edema test induced by arachidonic acid and croton oil; 2) the rat hind-paw edema test produced by several inflammatory inductors: carrageenan, dextran, zymosan, platelet-activating factor (PAF) and arachidonic acid; 3) a subacute model based on the rat carrageenan air-pouch granuloma test. Blood leukocyte free radical production was measured by flow cytometry with 2',7'-dichlorofluorescin diacetate (DCFH-DA) in vivo, in rats with induced air-pouch granuloma, and in a model in vitro. stimulating leukocytes with hydrogen peroxide. The aqueous extract of P. sagittalis showed a marked anti-inflammatory effect in both ear edema tests, dextran and carrageenan hind-paw edemas and carrageenan air-pouch model. It also had a potent antioxidant activity in blood leukocytes, both in vivo and in vitro. Our results correlate the reduction of free radical production with the anti-inflammatory effect of this plant.

Anti-inflammatory and analgesic activity of Baccharis trimera: identification of its active constituents

The butanolic fraction (BT-II) derived from the aqueous crude extract was prepared from aerial parts of Baccharis trimera and assessed in anti-inflammatory, analgesia, and ulcerogenesis models. Intraperitoneal pretreatment with lyophilized BT-II, at doses ranging from 40 to 100 mg/kg, markedly inhibited carrageenan- and dextran-induced inflammation (70.4-90.8% and 25.7-71.3%, respectively) and weakly decreased C16-paf- and arachidonic acid-induced swelling (24.9-36.7% and 0-30.6%, respectively). No effect was observed, at the same doses, on zymosan-induced edema. The intraperitoneal examination indicates that the anti-phlogistic action of BT-II was not due to an irritating effect at the injection site. Besides, BT-II reduced abdominal constrictions in mice following injection of acetic acid: at 50 mg/kg, it gave 67.4% inhibition and, at 100 mg/kg, 95.1%. The ulcerogenic assay showed that the incidence of ulcers after BT-II i.p. treatment was 2/6 at 50 mg/kg and 6/6 at 100 mg/kg. Ulcerogenic indices were 1.3 +/- 0.5 and 2.7 +/- 0.8, respectively. These results indicate that B.trimera shows strong anti-inflammatory and analgesic properties which seem to be due, at least partly, to the inhibition of prostaglandin biosynthesis. The chromatographic separation of BT-II monitored by bio-assay (carrageenan-induced edema test in mice) was carried out. The active constituents were found to be mainly saponins in which echinocystic acid (or its enantiomer) is the major aglycone, and also rutin.

Heart rate variability and inappropriate sinus tachycardia after catheter ablation of supraventricular tachycardia

Sinus tachycardia has been reported after radiofrequency catheter ablation of supraventricular tachycardia. Frequently, these patients require beta-blocking agents for symptomatic control. The purpose of this study was to evaluate prospectively the incidence of inappropriate sinus tachycardia and heart rate variability after ablation of atrioventricular nodal reentrant tachycardia and accessory pathways. Patients undergoing ablation had 24-h ambulatory monitoring ECG (Holter) performed before the procedure, on the day of the ablation, and 3 months afterwards. There were 170 patients, mean age 48 +/- 23 years; 93 were female. A complete study of the 24-h Holter with analysis of heart rate variability: SD, rMSSD, pNN50, high and low frequency was obtained. There was a low prevalence of inappropriate sinus tachycardia after the ablation procedure (10 of 170 patients: five with four atrioventricular nodal reentry, with posteroseptal accessory pathways and one of the latter following ablation of the left accessory pathway). There was no modification of time and frequency domain parameters of heart rate variability in the remaining patients who underwent radiofrequency ablation. Holter monitoring 3 months after ablation showed that parameters of heart rate and heart rate variability had normalized in patients who had developed inappropriate sinus tachycardia. Inappropriate sinus tachycardia may be initiated by both radiofrequency ablation of atrioventricular nodal reentrant tachycardia and radiofrequency ablation of posteroseptal accessory pathways. Specific damage to the posteroseptal region is responsible for these changes, which usually recover spontaneously after 3 months.

[An analysis of research projects on primary care presented to the Fondo de Investigación Sanitaria during 1991]

DESIGN

Observational cross-sectional study.

SETTING

Proposals on primary health care (domain, functions and activities) identified among a total of the 1412, belonging to all topics, submitted to the Fondo de Investigación Sanitaria during the 1991 exercise.

INTERVENTIONS

Proposals were classified according the degree of quality in the methodological fulfillment, pointed out those accepted for grant by the Technical Evaluation Committees.

MEASUREMENTS AND RESULTS

55 proposals about Primary Health Care were identified which account for 3.8% of the all proposals submitted. The degree of topic pertinence was very high with hypothesis and objectives well set out. There was a poor fulfillment of the methods and plan of action. Those projects with a very good fulfillment were accepted in a 90% of the cases.

CONCLUSIONS

The reviewed proposals shaw a good pertinence in the research on primary health care. We could notice a growing portion of researchers well trained with exigent methodological criteria. However, it remains a majority of proposals with poor methodological fulfillment which could easily be improved by increasing research training and expert support. Some advices are offered for the elaboration of research projects.

[Evaluation of the results of the research funded by the Health Research Fund in 1988]

BACKGROUND

To analyse the scientific product of research projects funded by Fondo de Investigación Sanitaria in 1988 emphasizing its relation to money granted.

METHODS

270 out of 610 projects were evaluated in relation to the amount granted. The number of papers published to each project and the impact factor assigned to the journals where these papers were published; we also assessed the mean cost of papers and impact factor units. These projects were coded following UNESCO classifications, and papers as per ISI standards.

RESULTS

A total of 95 projects out of the 270 analysed produced no papers; the other 175 projects yielded 471 articles (2.7 per project); the mean cost of each article was 1.1 million pesetas, or 0.8 million if only the productive projects were considered. These papers reached a total of 818,709 impact factor units; the mean cost of the impact factor unit is 660,796 pesetas, or 459,626 pesetas if only productive projects are considered.

CONCLUSIONS

Non productive projects were those that received less funding. 33% of projects produced papers published in journals with an assigned impact factor equal or inferior to one. There are evident differences among areas of knowledge in terms of impact factor. This study must be completed with a statistical analysis of reported data.

Common arterial trunk with absence of the left pulmonary artery in a 32-year-old man

We report a case of common arterial trunk with absence of the left pulmonary artery who was diagnosed at the age of 32 years. Pulmonary vascular disease made the condition inoperable. He does well with medical management after a follow-up of 20 months.

Fibrinolytic parameters and lipoprotein (a) levels in plasma of patients with coronary artery disease

Fibrinolysis and lipid disturbances have been considered as independent risk factors for coronary artery disease. Besides this, lipoprotein(a), which is characterized by its homology with plasminogen may interfere with the fibrinolytic function. To evaluate the eventual correlation between fibrinolytic parameters, lipoprotein (a) and other risk factors, 46 patients with coronary artery disease (34 with chronic angina pectoris and 12 with myocardial infarction) were studied. Increased basal values of t-PA antigen (8.2 and 6.6 vs. 4.2 ng/ml) but decreased response after stimulus (2.2 and 1.8 vs. 3.8 ng/ml) and increased levels of lipoprotein(a) (24.7 and 35.9 vs. 10.5 mg/dl) were the most relevant differences between coronary artery disease patients and controls. No correlation between lipoprotein(a) and fibrinolytic parameters was found. Therefore plasma concentration of the main plasma fibrinolytic parameters and lipoprotein(a) seem to be unrelated though the relevance of this interaction at a local level needs to be studied.

[The recurrence of duodenal ulcer in patients undergoing treatment with ranitidine and placebo. A multicenter study]

This randomised, double-blind multicenter study was conducted in order to evaluate the long-term effect (one year) of 150 mg ranitidine vs placebo in 51 patients with healed duodenal ulcer. Seventeen patients had ulcer recurrence at the end of follow-up, one among the 24 patients that received ranitidine and 16 among the 27 patients that received placebo (p = 0.00009). No side effects was detected. Our results support the usefulness of a one-year maintenance therapy with 150 mg ranitidine.

Treatment of portal systemic encephalopathy: standard and new treatments

The management of hepatic encephalopathy should be considered accordingly with the precipitating factor and the type of encephalopathy. Ideally the therapeutic approach must be useful for both acute and chronic forms of encephalopathy. Current treatment of hepatic encephalopathy consists of certain well-established measures attempting to identify and treat the precipitating factors, and to reduce the intestinal nitrogenous compounds formation and absorption by dietary restriction or bowel-cleansing with catartics or antibiotics such as neomycin, metronidazol, etc. This review describes briefly several therapeutic modalities.

[Sodium benzoate in portal-systemic-encephalopathy-induced blood ammonia normalization and clinical improvement. Interim report of a double-blind multicenter trial]

To investigate the therapeutic efficacy of sodium benzoate (SB) in a cirrotic population with chronic portal systemic encepalopathy (PSE), we performed a double blind, randomised, multicentric, clinical trial, comparing SB versus a standard therapy of lactitol (LA). To perform the study blind, syrups containing the two drugs were prepared. To date 27 patients have been studied. Of these, 12 received SB (5.6 g/day) and 15 received LA (29 g/day). Standard PSE parameters were assessed and hippurate urinary excretion was measured before and after the trial. For the SB group, basal and final PSE index were 0.39 +/- 0.16 and 0.17 +/- 0.1 respectively (p < 0.001). The Group on LA had a PSE index of 0.40 + 0.1 and 0.23 +/- 0.18 (basal and final respectively) (p < 0.001). The final hippurate excretion for SB group was 2498.9 mg/24 h. The hippurate excretion for the LA group suffer no changes (traces). No serious side effects were observed with either therapy. We suggested that SB is a safe, efficacious and comfortable alternate treatment for PSE.

[The tobacco habit in patients using home oxygen therapy]

The persistence of smoking habits results in a worse prognosis of patients with chronic airflow limitation. Some authors consider that oxygen therapy at home (OTH) is meaningless if the patient does not give up smoking. To assess the number of smokers in a group of 65 patients on OTH, a questionnaire on smoking habits was administered and the CO concentration in the expired air was measured. 27.7% of the study patients smoked; 12.3% admitted that they smoked on being questioned and the remaining 15.4% were identified by CO concentrations in the expired air equal to or higher than 10 ppm. There were no significant differences between the groups of smokers and nonsmokers regarding age and pulmonary function, but the rate of those declaring a poor compliance with OTH was higher among smokers.

Effects of protein-modifying reagents on an isoenzyme of potato apyrase

Treatment of an isoenzyme of potato apyrase of high adenosine triphosphatase/adenosine diphosphatase (ATPase/ADPase) ratio with iodine, N-acetylimidazole or tetranitromethane inactivates the ATPase activity of this enzyme faster than its ADPase activity. There was protection by substrates with the two last-named substances. This and the appearance of nitrotyrosine suggests the participation of tyrosyl residues in both enzymic activities of potato apyrase. The participation of thiol groups is excluded by the insensitivity of apyrase to p-chloromercuribenzoate. Also, 2-hydroxy-5-nitrobenzyl bromide or carboxymethylation produce the same rate of inactivation of ATPase and ADPase activities. Substrates protect both activities from inactivation. Hydrogen peroxide and photo-oxidation inactivate ATPase activity faster than ADPase activity. There is no protection by substrates. Analysis of pH effects on V(max.) and K(m) suggest different pK values for the amino acid residues at the ATP and ADP sites.