Aerosol sources in subway environments.

Millions of people use rail subway public transport around the world, despite the relatively high particulate matter (PM) concentrations in these underground environments, requiring the identification and quantification of the aerosol source contributions to improve the air quality. An extensive aerosol monitoring campaign was carried out in eleven subway stations in the Barcelona metro system, belonging to seven subway lines. PM2.5 samples were collected during the metro operating hours and chemically analysed to determine major and trace elements, inorganic ions, and total carbon. The chemical compositions of subway components such as brake pads, rail tracks and pantographs were also determined. The mean PM2.5 concentrations varied widely among stations, ranging from 26 µg m-3 to 86 µg m-3. Subway PM2.5 was mainly constituted by Fe2O3 (30-66%), followed by carbonaceous matter (18-37%) for the old stations, while for new stations equipped with Platform Screen Doors (PSD) these percentages go down to 21-44% and 15-30%, respectively. Both the absolute concentrations and the relative abundance of key species differed for each subway station, although with common patterns within a given subway line. This is a result of the different emission chemical profiles in different subway lines (using diverse types of brakes and/or pantographs). The co-emission of different sources poses a problem for their separation by receptor models. Nevertheless, receptor modelling (Positive Matrix Factorization) was applied resulting in ten sources, five of them subway-specific: RailWheel, RailWheel+Brake, Brake_A, Brake_B, Pb. The sum of their contributions accounted for 43-91% of bulk PM2.5 for the old stations and 21-52% for the stations with PSD. The decrease of the activity during the weekends resulted in a decrease (up to 56%) in the subway-specific sources contribution to the -already lower- bulk PM2.5 concentrations compared to weekdays. The health-related elements are mainly apportioned (> 60%) by subway sources.

Developmental maturation of presynaptic ribbon numbers in chicken basilar-papilla hair cells and its perturbation by long-term overexpression of Wnt9a.

The avian basilar papilla is a valuable model system for exploring the developmental determination and differentiation of sensory hair cells and their innervation. In the mature basilar papilla, hair cells form a well-known continuum between two extreme types-tall and short hair cells-that differ strikingly in their innervation. Previous work identified Wnt9a as a crucial factor in this differentiation. Here, we quantified the number and volume of immunolabelled presynaptic ribbons in tall and short hair cells of chickens, from developmental stages shortly after ribbons first appear to the mature posthatching condition. Two longitudinal locations were sampled, responding to best frequencies of approximately 1 kHz and approximately 5.5 kHz when mature. We found significant reductions of ribbon number during normal development in the tall-hair-cell domains, but stable, low numbers in the short-hair-cell domains. Exposing developing hair cells to continuous, excessive Wnt9a levels (through virus-mediated overexpression) led to transiently abnormal high numbers of ribbons and a delayed reduction of ribbon numbers at all sampled locations. Thus, (normally) short-hair-cell domains also showed tall-hair-cell like behaviour, confirming previous findings (Munnamalai et al., 2017). However, at 3 weeks posthatching, ribbon numbers had decreased to the location-specific typical values of control hair cells at all sampled locations. Furthermore, as shown previously, mature hair cells at the basal, high-frequency location harboured larger ribbons than more apically located hair cells. This was true for both normal and Wnt9a-overexposed basilar papillae.

Benefits of EEG-Neurofeedback on the Modulation of Impulsivity in a Sample of Cocaine and Heroin Long-Term Abstinent Inmates: A Pilot Study.

The aim of this pilot study was to assess whether neurofeedback (NFB) can be useful in the treatment of impulsive behavior in long-term abstinent cocaine and heroin addicts. A single-blind sham-controlled NFB protocol was carried out to assess the effects of NFB on impulsivity in 20 (10 + 10) cocaine and heroin long-term abstinent addicts (Diagnostic and Statistical Manual of Mental Disorders [4th ed., text rev.; DSM-IV-TR]). Psychotic and neurologic diseases were excluded. Participants underwent 40 NFB sessions based on the very slow cortical potential range. Inhibitory deficits were specifically addressed through right and left prefrontal training. Clinical improvement was measured with Likert-type scales, the Hamilton Depression Rating Scale, and the State-Trait Anxiety Inventory, and impulsivity was assessed using the Barratt Impulsiveness Scale and the Continuous Performance Test. Although the results are preliminary due to the small sample size, the NFB-treated group showed a significant clinical improvement, including symptoms of anxiety and depression, with two differentiated time periods. No significant clinical improvement was found in the control group. A significant decrease in the post- versus pre-treatment measures of global impulsivity, nonplanning impulsivity, and error commission measures was found in the NFB-treated group; effect size (dKorr) in the pre-post control design was moderate. No significant change was found in the control group. Despite the limitations of this study, the results suggest that NFB is better than placebo in improving impulsivity and clinical symptoms of anxiety and depression in long-term abstinent cocaine- and heroin-dependent individuals.

[The laryngeal tube]. / El tubo laríngeo.

The laryngeal tube (VBM Medizintechnic GmbH, Sulz, Germany) is a supraglottic device designed for airway management in spontaneous or positive-pressure ventilation during anesthesia or in cardiopulmonary resuscitation. Currently, the tube is available in 4 versions: the standard laryngeal tube, the disposable tube (LT-D), the dual-lumen tube (with a tube for suction) (LTS II), and the disposable LTS (LTS-D). The design of the tube has been modified several times. It is easy to insert and the airway seal is more effective than that of the laryngeal mask. The incidence of complications is similar for both devices, though use of the laryngeal tube requires more adjustments. The standard tube is somewhat less effective than the ProSeal laryngeal mask, though the new LTS II has been improved considerably. The laryngeal tube is effective as an aid to management of the difficult airway. We reviewed the literature indexed on MEDLINE through December 2006 using the search terms laryngeal tube, anesthesia, equipment, and airway.

Formation and alteration of airborne particles in the subway environment.

Most particles in the rail subway environment are sub-micron sized ferruginous flakes and splinters generated mechanically by frictional wear of brake pads, wheels and rails. To better understand the mechanisms of formation and the alteration processes affecting inhalable particles in subways, PM samples (1-2.5 µm and 2.5-10 µm) were collected in the Barcelona Metro and then studied under a scanning electron microscope. Most particles in these samples are hematitic (up to 88%), with relatively minor amounts of mineral matter (up to 9%) and sulphates (up to 5%). Detailed microscopy (using back scattered and TEM-DRX imaging) reveals how many of the metallic particles comprise the metallic Fe nucleus surrounded by hematite (Fe2O3) and a coating of sulphate and chloride salts mixed with mineral matter (including Ca-carbonates, clay minerals and quartz). These observations record the emission of fine to ultrafine FePM by frictional wear at elevated temperatures that promote rapid partial (or complete) oxidation of the native metal. Water condensing on the PM surface during cooling leads to the adsorption of inorganic mineral particles that coat the iron oxide. The distinctively layered polymineralic structure that results from these processes is peculiar to particles generated in the subway environment and very different from PM typically inhaled outdoors.

Cell proliferation patterns in the wing imaginal disc of Drosophila.

Morphogenetic processes, based on the temporal and spatial control of cell proliferation, are involved in determining the size and shape of an organism. We have used clonal analysis, employing X-ray-induced mitotic recombination, to study cell proliferation and differentiation processes in the developing wing imaginal disc of Drosophila. Our results show a non-uniform distribution of mitotic activities during different stages of wing development. This may reflect waves of cell proliferation which derive from distinct centers of cell proliferation within the growing wing imaginal disc. These proliferation centers are located within the major wing compartments (i.e. the anterior, posterior, dorsal and ventral compartments) and they are restricted to the areas which give rise to the intervein regions of the adult wing. The mitotic recombination analysis, combined with the study of Minute and gynandromorph mosaics, show that the presumptive vein regions of the wing represent distinct boundaries which delimit the proliferation centers to the intervein regions. We present a generative model of wing morphogenesis that is consistent with our results.

The efficiency of potassium removal during bicarbonate hemodialysis.

Patients on chronic hemodialysis often portray high serum [K+]. Although dietary excesses are evident in many cases, in others, the cause of hyperkalemia cannot be identified. In such cases, hyperkalemia could result from decreased potassium removal during dialysis. This situation could occur if alkalinization of body fluids during dialysis would drive potassium into the cell, thus decreasing the potassium gradient across the dialysis membrane. In 35 chronic hemodialysis patients, we compared two dialysis sessions performed 7 days apart. Bicarbonate or acetate as dialysate buffers were randomly assigned for the first dialysis. The buffer was switched for the second dialysis. Serum [K+], [HCO3-], and pH were measured in samples drawn before dialysis; 60, 120, 180, and 240 min into dialysis; and 60 and 90 min after dialysis. The potassium removed was measured in the dialysate. During the first 2 hr, serum [K+] decreased equally with both types of dialysates but declined more during the last 2 hr with bicarbonate dialysis. After dialysis, the serum [K+] rebounded higher with bicarbonate bringing the serum [K+] up to par with acetate. The lower serum [K+] through the second half of bicarbonate dialysis did not impair potassium removal (295.9 +/- 9.6 mmol with bicarbonate and 299.0 +/- 14.4 mmol with acetate). The measured serum K+ concentrations correlated with serum [HCO3-] and blood pH during bicarbonate dialysis but not during acetate dialysis. Alkalinization induced by bicarbonate administration may cause redistribution of K during bicarbonate dialysis but this does not impair its removal. The more marked lowering of potassium during bicarbonate dialysis occurs late in dialysis, when exchange is negligible because of a low gradient.

Sunflower metallothionein family characterisation. Study of the Zn(II)- and Cd(II)-binding abilities of the HaMT1 and HaMT2 isoforms.

Plant metallothioneins (MTs) constitute a family of small Cys-rich proteins capable of coordinating metal ions, significantly differing from microbial and animal MTs. They are divided into four subfamilies depending on the Cys pattern in their sequence. In this work, the MT system of the sunflower plant (Helianthus annuus) has been defined, with ten genes coding for MTs (HaMT) belonging to the four plant MT subfamilies; three HaMT1, four HaMT2, one HaMT3 and two HaMT4 isoforms. The gene expression pattern and capacity to confer metal resistance to yeast cells have been analysed for at least one member of each subfamily. The divalent metal ion-binding abilities of HaMT1-2 and HaMT2-1 (the isoforms encoded by the most abundantly expressed HaMT1 and HaMT2 isogenes) have been characterised, as HaMT3 and HaMT4 were previously studied. Those isoforms constitute an optimum material to study the effect of Cys number variability on their coordination abilities, as they exhibit additional Cys residues regarding the canonical Cys pattern of each subfamily. Our results show that the variation in the number of Cys does not drastically modify their M(II)-binding abilities, but instead modulates the degree of heterogeneity of the corresponding recombinant syntheses. Significantly, the Zn(II)-HaMT1 complexes were highly susceptible to proteolytic cleavage. The recombinant Cd-MT preparations of both isoforms exhibit significant acid-labile sulphide content-Cd6S8 or Cd7S7 species. Overall results suggest that HaMT2-1 is probably associated with Cd(II) detoxification, in contrast to HaMT1-2, which may be more related to physiological functions, such as metal ion transport and delivery.

MTO: the second member of a Drosophila dual copper-thionein system.

Drosophila MTO metal binding features were analyzed for comparison with MTN, the paralogous Drosophila metallothionein, and to classify MTO as either zinc- or copper-thionein. This was achieved by a combination of in vivo, in vitro and in silico methodologies. All the results unambiguously classified MTO as a second Drosophila copper-thionein, putting Drosophila forward as the only metazoan in which any zinc-thionein has still to be reported. Interestingly, experimental data only showed minor differences in the coordinative behavior of both MTs, but provided a characteristic spectroscopic fingerprint, revealing the possible binding of chloride anions in certain metal-MTO aggregates.

Drosophila MTN: a metazoan copper-thionein related to fungal forms.

Two Drosophila metallothioneins (MT) have been reported: MTN, a 40 residue peptide including 10 Cys, and MTO, a 43 residue peptide including 12 Cys. However, neither functional nor evolutionary analyses for either of the Drosophila MT are available. Here, heterologous expression of Mtn in Escherichia coli is reported. The metal binding abilities of the Cu- and Zn-MTN complexes conformed in vivo, as well as the features of the Cd- and Cu-aggregates produced by metal replacement in vitro, have been determined by atomic emission spectrometry, circular dichroism and electrospray ionization mass spectrometry. Primary structure relationships with other MT have been examined. The results indicate a close resemblance of MTN to fungal copper-thioneins.

A new insight into the Ag+ and Cu+ binding sites in the metallothionein beta domain.

The copper(I) and silver(I) binding properties of the beta fragment of recombinant mouse metallothionein I have been studied by electronic absorption and circular dichroism spectroscopy. When possible, the stoichiometry of the species formed was confirmed by electrospray mass spectrometry. The behaviour observed differs from that reported for the native protein. Titration of either Zn3-beta MT at pH 7 or apo-beta MT at pH 3 with Cu+ leads to the formation of species having the same stoichiometry and structure: Cu6-beta MT, Cu7-beta MT and Cu10-beta MT. In the first stage of the titration of Zn3-beta MT with Cu+ at pH 7 one additional species of formula Cu4Zn1-beta MT was detected. In contrast, the titration of Zn3-beta MT at pH 7.5 and of apo-beta MT at pH 2.5 with Ag+ proceeds through different reaction pathways, affording ZnxAg3-beta MT, Ag6-beta MT and Ag9-beta MT or Ag3-beta MT, Ag6-beta MT and Ag9-beta MT, respectively. The CD envelope corresponding to species with the same stoichiometric ratio, Ag6-beta MT and Ag9-beta MT, indicates that they have a different structure at each pH value. On the basis of the differences observed, the postulated similarity between copper and silver binding to metallothionein may be questioned.

Binding of excess cadmium(II) to Cd7-metallothionein from recombinant mouse Zn7-metallothionein 1. UV-VIS absorption and circular dichroism studies and theoretical location approach by surface accessibility analysis.

A mouse metallotbionein (MT) 1 expression system has been constructed that renders recombinant MT as a high purity Zn-coordinated protein. Spectral changes in absorption and circular dichroism following the addition of up to 7 mol equivalents of Cd2+ to recombinant Zn7-MT showed that it behaves like the native protein. Exposure of Cd7-MT to Cd2+ resulted in further binding of these ions to the protein, although saturation was not achieved on the addition of up to 22 mol equivalents of Cd2+ to Zn7-MT. Spectral data are compatible with a model in which the first four additional Cd2+ ions are bound to Cd7-MT via sulfur atoms, and indicate that no further thiol groups are involved in the binding of the excess Cd(II) over 11. Cd2+ ions bound in excess to Cd7-MT appear to have lower binding constants as exposure of Cdn-MT (n > 7) species to Cbelex-100 retrieved Cd7-MT. Based on the X-ray data, the accessible surface areas of sulfur atoms in Cd5,Zn2-MT 2 were calculated. This led us to propose that the coordination of the first three additional Cd(II) ions to Cd7-MT proceeds by means of S-Met1-O-Met1, S-Cys7-S-Cys13 and S-Cys5-S-Cys26 pairs. Finally, comparison of the behavior of the entire MT with that of the recombinant alpha MT and beta MT subunits indicates that mutual influences may not be negligible.

[Adverse effects of dobutamine stress echocardiography]. / Efectos secundarios de la ecocardiografía de estrés con dobutamina.

OBJECTIVES: To study the side effects of dobutamine echocardiography and to define the protocol with less side effects. PATIENTS AND METHODS: Since June 1992 to November 1994 dobutamine echocardiography was performed on two different groups of patients. In the first, the test was preoperatively done to evaluate the surgical risk. The remaining were patients with angina. Dobutamine was started at a dose of 5 micrograms/kg/min and increased up to a total dose of 40 micrograms/kg/min. Since March 1993 atropine was added if the heart rate was under 90 beats/min. RESULTS: One hundred and forty one patients were included (76 for a preoperatory appraisal and 65 with angina). Echocardiography test was not performed on 3 patients (2 with pulmonary disease and 1 with a therapeutic neumothorax). Among the remaining 138 patients, side effects appeared in 53 patients (38%) and test had to be prematurely interrupted in 11 (8%) of them. Side effects presented during the test in 9 (7%) although it could be finished and at the end of the test in 33 (24%). The most frequent side effects were arrhythmias that appeared in 28 patients (20%) and were considered significant in 17: 7 with supraventricular tachycardia, 7 with more than 6 ventricular premature systoles per minute, 2 with ventricular tachycardia and 1 with multifocal supraventricular premature systoles. These arrhythmias were observed when the dose of dobutamine was 20 micrograms/kg/min or more (p < 0.05). Hypotension developed in 11 patients (8%) and noncardiac effects in 13 (9%). The dobutamine test was interrupted for arrhythmias in 4% of cases, noncardiac side effects in 2% and poor image quality in 3%. A steady increment of heart rate 5 minutes after infusion of atropine was detected in 12 patients (maximal: 93 +/- 23 beats per minute; after five minutes: 94 +/- 19) and side effects were encountered in only one of these patients (hypotension). CONCLUSIONS: Intravenous administration of dobutamine during echocardiography can be finished in the majority of patients with good tolerance in spite of its side effects. Arrhythmias with dose over 20 micrograms/kg/min, poor image quality and chronotropic insufficiency are the most frequently encountered limitations.

[Association between ischemic heart disease and peptic ulcer. A case-control study]. / Asociación entre cardiopatía isquémica y ulcus péptico. Estudio de casos y controles.

AIM: To determine whether patients with ischemic heart disease (IHD) are at higher risk for peptic ulcer (PU). MATERIAL AND METHODS: We performed a case-control study. The patients were selected by simple random sampling of clinical histories. CASES: 310 patients with IHD (angina pectoris, myocardial infarct or both). CONTROLS: 310 patients without IHD, paired by age, sex and tobacco consumption. Data were obtained by review of the patients' clinical histories. Response variable: diagnosis of peptic ulcer by endoscopy, esophagogastroduodenal transit or surgery. The odds ratio (OR) was determined by logistic regression, adjusting for the effect of confounding variables and risk for PU. RESULTS: The mean age of the patients was 72.7 years (SD 8.6) and 70% were men. PU was found in 18.7% of the patients and in 12.3% of the controls with an adjusted OR of 1.77 (95% CI: 1.12-2.77; p = 0.01). This effect was produced at the expense of duodenal ulcer with an adjusted OR of 2.22 (95% CI: 1.29-3.74; p = 0.003). The adjusted OR of gastric ulcer was 1.13 (95% CI: 0.45-2.82; p = 0.8). CONCLUSIONS: After adjusting for the effect of confounding variables and risk factors for the development of PU, this disease was more frequent in the group of patients with IHD.

[Cutaneous pigmentation, only manifestation of porphyria cutanea tarda in a HIV-1 positive patient]. / Pigmentation cutanée, seule manifestation d'une porphyrie cutanée tardive chez un malade séropositif pour le VIH1.

INTRODUCTION: Porphyria cutanea tarda (PCT) is an unfrequent disorder in patients with acquired immunodeficiency syndrome (AIDS) due to deficiency in uroporphyrinogen decarboxilase. The more frequent cutaneous manifestations are skin fragility and hypertrichosis. CASE REPORT: A 44-years-old man with AIDS presented an intense cutaneous hyperpigmentation, preferently involving sun-exposed areas. Histopathologic studies showed perivascular PAS-positive deposits. Biochemical studies confirmed the diagnosis of PCT. DISCUSSION: PCT should be included in the differential diagnosis of cutaneous hyperpigmentation in patients infected by human immunodeficiency virus (HIV).

[Solitary adrenal gland hydatid cyst]. / Quiste hidatídico suprarenal solitario.

Presentation of one case of solitary suprarenal hydatid cyst. Clinical diagnosis was made from a right lumbar pain, achieving identification of the parasitic disease by radiological and biological means. Treatment combined mebendazole and surgery. Both therapeutical options are discussed.

[Duodenal duplication]. / Duplicación duodenal.

Cystic duplication of the duodenum is a rare anomaly of the gastrointestinal tract. This is a report of a newborn with a cystic duplication of duodenum diagnosed prenatally. It's relevant the few clinical symptoms of a such big mass. The surgical procedure was excision of the cyst, with a good post operative curse.

[Silastic catheters: pinpointing the end tip of the catheter by means of electrocardiographic monitoring]. / Catéteres de silastic. Localización del extremo distal mediante monitorización electrocardiográfica.

The placement of catheters with a silastic center has been a common procedure in neonatal intensive care units for several years. Nonetheless, this procedure, like many others, bears its risks and complications if not properly carried out. The majority of complications, which are described in medical journals, include arrhythmias, myocardiac perforations, thrombosis, hemorrhage in the pleura, etc., and these are related with the catheter and its possible movement inside the blood vessel where it was originally inserted. The usual exploratory procedure to pinpoint the end tip of the catheter has been an ordinary x-ray, but often this x-ray does not allow one to see precisely where the catheter tip is located. This problem is caused by the tiny catheter calibre which does not allow for all the necessary contrast; because of this, it is frequently necessary to administer a radiopaque contrasting sub-stance and then repeat the x-ray in order to ensure that the catheter tip is located exactly where it should be. By means of electrocardiographic monitoring, a three-pronged key with an electrode and a 5.85% sodium chloride solution, it is possible to pinpoint the end tip of the catheter without resorting to an x-ray nor administering a contrasting solution.

Attempted and completed suicide: not what we expected?

BACKGROUND: Suicide attempters and suicide completers are two overlapping but distinct suicide populations. This study aims to present a more accurate characterization by comparing populations of suicide attempters and completers from the same geographical area. METHODS: Samples and procedure: All cases of attempted suicide treated at the emergency room of the Corporacio Sanitària i Universitària Tauli Parc de Sabadell in 2008 (n=312) were compared with all completed suicides recorded in the same geographical area from 2008 to 2011 (n=86). Hospital and primary care records were reviewed for sociodemographic and clinical variables. STATISTICAL ANALYSIS: Chi-square, ANOVA, and Mann-Whitney U tests were used to identify characteristics related to suicide completion. RESULTS: Compared to suicide attempters, suicide completers were more likely to be male (73.3% vs. 37.8%; p<0.001), pensioners (73.7% vs. 23.4%; p<0.001), and people living alone (31.8% vs. 11.4%; p=0.006). Suicide completers more frequently presented somatic problems (71.7 vs. 15.7; p<0.001), Major Depressive Disorder (54.7% vs. 27.9%; p<0.001), and made use of more lethal methods (74.1 vs. 1.9; p<0.001). Suicide completers were more likely to have been followed by a primary care provider (50.0% vs. 16.0%; p<0.001). 92.3% of the suicides committed were completed during the first or second attempt. LIMITATIONS: Suicide completers were not evaluated using the psychological autopsy method. CONCLUSIONS: Despite presenting a profile of greater social and clinical severity, suicide completers are less likely to be followed by Mental Health Services than suicide attempters. Current prevention programs should be tailored to the specific profile of suicide completers.

The response of the different soybean metallothionein isoforms to cadmium intoxication.

Cadmium is a highly toxic heavy metal for both plants and animals. The presence of Cd in agricultural soils is of major concern regarding its entry into the food chain, since Cd compounds are readily taken up by plants, and accumulated in edible parts due to their high solubility. In this study, we first demonstrate the high capacity for Cd concentration of soybean grains. Consequently, we considered the study and characterization of the molecular determinants of Cd accumulation -such as metallothioneins (MT)- to be of major practical importance. We report here the first characterization of the soybean MT system, with the identification of nine genes (one of which is a truncated pseudogene), belonging to the four plant MT types. The most highly expressed of each type was chosen for further function analysis. All of them are expressed at high levels in soybean tissues: GmMT1, GmMT2 and GmMT3 in roots, shoots and seeds, and GmMT4 only in seeds. The corresponding recombinant soybean MTs, synthesized in Escherichia coli cells cultured in metal supplemented media, exhibit greater cadmium than zinc binding capacity. These results suggest a definite role of GmMTs in Cd(II) accumulation as one of the main responses of soybean to an overload of this metal.