25 research outputs found
A compilation of field surveys on gaseous elemental mercury (GEM) from contrasting environmental settings in Europe, South America, South Africa and China: separating fads from facts
Mercury is transported globally in the atmosphere
mostly in gaseous elemental form (GEM, Hg0
gas),
but still few worldwide studies taking into account
different and contrasted environmental settings are
available in a single publication. This work presents
and discusses data from Argentina, Bolivia, Bosnia
and Herzegovina, Brazil, Chile, China, Croatia, Finland,
Italy, Russia, South Africa, Spain, Slovenia and
Venezuela. We classified the information in four
groups: (1) mining districts where this contaminant
poses or has posed a risk for human populations and/or
ecosystems; (2) cities, where the concentration ofatmospheric mercury could be higher than normal due
to the burning of fossil fuels and industrial activities;
(3) areas with natural emissions from volcanoes; and
(4) pristine areas where no anthropogenic influence
was apparent. All the surveys were performed using
portable LUMEX RA-915 series atomic absorption
spectrometers. The results for cities fall within a low
GEM concentration range that rarely exceeds 30 ng m-3,
that is, 6.6 times lower than the restrictive ATSDR
threshold (200 ng m-3) for chronic exposure to this
pollutant. We also observed this behavior in the former
mercury mining districts, where few data were above
200 ng m-3.We noted that high concentrations of GEM
are localized phenomena that fade away in short
distances. However, this does not imply that they do not
pose a risk for those working in close proximity to the
source. This is the case of the artisanal gold miners that
heat the Au–Hg amalgam to vaporize mercury. In this
respect, while GEM can be truly regarded as a hazard,
because of possible physical–chemical transformations
into other species, it is only under these localized
conditions, implying exposure to high GEM concentrations,
which it becomes a direct risk for humans.Grants
CGL2009-13171 and CTM2012-33918 from the Spanish
Ministry of Economy and Competitiveness and PII1I09-0142-
4389 from theCastilla-LaMancha (Spain)RegionalGovernment.Published713-7346A. Monitoraggio ambientale, sicurezza e territorioJCR Journalrestricte
Author Correction: The messy death of a multiple star system and the resulting planetary nebula as observed by JWST
Stars and planetary system
Plasmodium vivax malaria at households: spatial clustering and risk factors in a low endemicity urban area of the northwestern Peruvian coast
Radiosinovectomía de muñeca guiada por ultrasonido: Experiencia de un caso clínico y revisión del tema Ultrasound-guided wrist radiosynovectomy: Case report and topic review
La radiosinovectomía es una forma local de radioterapia utilizada como tratamiento de segunda línea en el manejo de artropatías inflamatorias y no inflamatorias con respuesta insatisfactoria a la terapia sistémica o local con corticoesteroides. Tiene una eficacia similar a la sinovectomía quirúrgica, con las ventajas de ser un tratamiento de menor costo, menos cruento y con menor tiempo de convalecencia. Su eficacia es mayor en artropatías inflamatorias caracterizadas por sinovitis, como la artritis reumatoide y artritis crónica juvenil, con compromiso mono u oligoarticular y en articulaciones de extremidades superiores. Existen múltiples isótopos que se pueden utilizar en suspensiones coloidales, siendo el sulfuro coloidal de renio-186 el utilizado para la articulación radiocarpiana. Una técnica de administración adecuada es fundamental para el éxito del tratamiento, siendo la inyección con guía ultrasonográfica adecuada para articulaciones de volumen pequeño, instancia en la que la colaboración del médico radiólogo entrenado es fundamental.<br>Radiosynovectomy is a local form of radiotherapy used as second-line treatment in the management of inflammatory and non-inflammatory arthropathies with unsatisfactory response to local or systemic corticosteroid therapy. Its efficacy is similar to that of surgical synovectomy, with the advantages of being a low-cost and minimally- invasive treatment that requires a shorter recovery time. Its efficacy is greater in the treatment of inflammatory arthritis characterized by synovitis, such as rheumatoid arthritis and juvenile chronic arthritis with mono/ oligoarticular involvement, especially in upper extremity joints. A number of isotopes can be used in colloidal suspensions. Rhenium-186-sulphide colloid is currently indicated for the treatment of medium-sized joints. The ultrasound-guided injection is suitable for small joints, such as wrist. For proper and safe use and administration of this technique the collaboration of a trained and experienced radiologist is critical to successful treatment
Proapoptotic effect of endocannabinoids in prostate cancer cells
Artículo de publicación ISIIn the early stages, prostate cancer is androgendependent;
therefore, medical castration has shown significant
results during the initial stages of this pathology. Despite this
early effect, advanced prostate cancer is resilient to such treatment.
Recent evidence shows that derivatives of Cannabis
sativa and its analogs may exert a protective effect against
different types of oncologic pathologies. The purpose of the
present study was to detect the presence of cannabinoid receptors
(CB1 and CB2) on cancer cells with a prostatic origin and
to evaluate the effect of the in vitro use of synthetic analogs. In
order to do this, we used a commercial cell line and primary
cultures derived from prostate cancer and benign prostatic
hyperplasia. The presence of the CB1 and CB2 receptors
was determined by immunohistochemistry where we showed
a higher expression of these receptors in later stages of the
disease (samples with a high Gleason score). Later, treatments
were conducted using anandamide, 2-arachidonoyl
glycerol and a synthetic analog of anandamide, methanandamide.
Using the MTT assay, we proved that the treatments
produced a cell growth inhibitory effect on all the different
prostate cancer cultures. This effect was demonstrated to be
dose-dependent. The use of a specific CB1 receptor blocker
(SR141716) confirmed that this effect was produced primarily
from the activation of the CB1 receptor. In order to understand
the MTT assay results, we determined cell cycle distribution by
flow cytometry, which showed no variation at the different cell
cycle stages in all the cultures after treatment. Treatment with
endocannabinoids resulted in an increase in the percentage of
apoptotic cells as determined by Annexin V assays and caused
an increase in the levels of activated caspase-3 and a reduction
in the levels of Bcl-2 confirming that the reduction in cell
viability noted in the MTT assay was caused by the activation
of the apoptotic pathway. Finally, we observed that endocannabinoid
treatment activated the Erk pathway and at the same
time, produced a decrease in the activation levels of the Akt
pathway. Based on these results, we suggest that endocannabinoids
may be a beneficial option for the treatment of prostate
cancer that has become nonresponsive to common therapies.Vicerrectoria de Investigacion y Desarrrollo of Universidad de Chile (VID)
DI MULT 05/36-2
FONDECYT
1060500
1110269
1140417
Grant DI MULT 05/36-2. Grants FONDECYT, 1060500 (H.C.),
1110269 (H.C.) and 1140417 (E.C.)
Socioemotional wealth, entrepreneurial orientation and international performance of family firms
This paper analyses the relationships between the socioemotional
wealth, entrepreneurial orientation and international performance
of family firms. This research is pioneering in that it seeks to
explain the international performance of family firms from the
non-economic perspective of entrepreneurial orientation determined
by socioemotional wealth. Second generation structural
equation modelling (PLS-SEM) using SmartPLS 3.2.8 software was
applied to data from 106 Spanish family firms. The study shows
that considering socioemotional wealth substantially improves the
capacity of entrepreneurial orientation to explain variation in the
international performance of family firms. When only entrepreneurial
orientation is included in the model, the explained
variance of international performance is 34.2%. However, when
socioemotional wealth is included in the model as an antecedent
of international performance, the explained variance increases
to 42.6%
Socioemotional wealth, entrepreneurial orientation and international performance of family firms
Assessing malaria transmission in a low endemicity area of north-western Peru
Abstract
Background
Where malaria endemicity is low, control programmes need increasingly sensitive tools for monitoring malaria transmission intensity (MTI) and to better define health priorities. A cross-sectional survey was conducted in a low endemicity area of the Peruvian north-western coast to assess the MTI using both molecular and serological tools.
Methods
Epidemiological, parasitological and serological data were collected from 2,667 individuals in three settlements of Bellavista district, in May 2010. Parasite infection was detected using microscopy and polymerase chain reaction (PCR). Antibodies to Plasmodium vivax merozoite surface protein-119 (PvMSP119) and to Plasmodium falciparum glutamate-rich protein (PfGLURP) were detected by ELISA. Risk factors for exposure to malaria (seropositivity) were assessed by multivariate survey logistic regression models. Age-specific antibody prevalence of both P. falciparum and P. vivax were analysed using a previously published catalytic conversion model based on maximum likelihood for generating seroconversion rates (SCR).
Results
The overall parasite prevalence by microscopy and PCR were extremely low: 0.3 and 0.9%, respectively for P. vivax, and 0 and 0.04%, respectively for P. falciparum, while seroprevalence was much higher, 13.6% for P. vivax and 9.8% for P. falciparum. Settlement, age and occupation as moto-taxi driver during previous year were significantly associated with P. falciparum exposure, while age and distance to the water drain were associated with P. vivax exposure. Likelihood ratio tests supported age seroprevalence curves with two SCR for both P. vivax and P. falciparum indicating significant changes in the MTI over time. The SCR for PfGLURP was 19-fold lower after 2002 as compared to before (λ1 = 0.022 versus λ2 = 0.431), and the SCR for PvMSP119 was four-fold higher after 2006 as compared to before (λ1 = 0.024 versus λ2 = 0.006).
Conclusion
Combining molecular and serological tools considerably enhanced the capacity of detecting current and past exposure to malaria infections and related risks factors in this very low endemicity area. This allowed for an improved characterization of the current human reservoir of infections, largely hidden and heterogeneous, as well as providing insights into recent changes in species specific MTIs. This approach will be of key importance for evaluating and monitoring future malaria elimination strategies