Standardised packs and larger health warnings: visual attention and perceptions among Colombian smokers and non-smokers.

AIMS: To measure how cigarette packaging (standardised packaging and branded packaging) and health warning size affect visual attention and pack preferences among Colombian smokers and non-smokers. DESIGN: To explore visual attention, we used an eye-tracking experiment where non-smokers, weekly smokers and daily smokers were shown cigarette packs varying in warning size (30%-pictorial on top of the text, 30%-pictorial and text side-by-side, 50%, 70%) and packaging (standardised packaging, branded packaging). We used a discrete choice experiment (DCE) to examine the impact of warning size, packaging and brand name on preferences to try, taste perceptions and perceptions of harm. SETTING: Eye-tracking laboratory, Universidad Nacional de Colombia, Bogotá, Colombia. PARTICIPANTS: Participants (n = 175) were 18 to 40 years old. MEASUREMENTS: For the eye-tracking experiment, our primary outcome measure was the number of fixations toward the health warning compared with the branding. For the DCE, outcome measures were preferences to try, taste perceptions and harm perceptions. FINDINGS: We observed greater visual attention to warning labels on standardised versus branded packages (F[3,167] = 22.87, P < 0.001) and when warnings were larger (F[9,161] = 147.17, P < 0.001); as warning size increased, the difference in visual attention to warnings between standardised and branded packaging decreased (F[9,161] = 4.44, P < 0.001). Non-smokers visually attended toward the warnings more than smokers, but as warning size increased these differences decreased (F[6,334] = 2.92, P = 0.009). For the DCE, conditional trials showed that increasing the warning size from 30% to 70% reduced preferences to try (odds ratio [OR] = 0.48, 95% CI = [0.42,0.54], P < 0.001), taste perceptions (OR = 0.61, 95% CI = [0.54,0.68], P < 0.001); and increased harm perceptions (OR = 0.78, 95% CI = [0.76,0.80], P < 0.001). Compared with branded packaging, standardised packaging reduced our DCE outcome measures with ORs ranging from OR = 0.25 (95% CI = [0.17,0.38], P < 0.001) to OR = 0.79 (95% CI = [0.67,0.93], P < 0.001) across two brands. These effects were more pronounced among non-smokers, males and younger participants. Unconditional trials showed similar results. CONCLUSIONS: Standardised cigarette packaging and larger health warnings appear to decrease positive pack perceptions and have the potential to reduce the demand for cigarette products in Colombia.

Iron status in late pregnancy is inversely associated with birth weight in Colombia.

OBJECTIVE: Gestational anaemia (GA) is common in developing countries. This study assessed the relationship of late GA and negative perinatal outcomes in participants recruited in a reference maternity unit of the Caribbean region of Colombia. DESIGN: Prospective analytical birth cohort study. Maternal Hb and serum ferritin (SF) levels were measured. GA was defined as Hb levels <6·82 mmol/l (<11 g/dl), SF depletion as SF levels <12 µg/l. Birth outcomes such as low birth weight (LBW), preterm birth (PB) and small for gestational age (SGA) were examined. SETTING: Mothers in the first stage of labour, living in urban or rural areas of Bolívar, were enrolled in an obstetrical centre located in Cartagena, Colombia. Blood and stool samples were taken prior delivery. Maternal blood count, SF levels and infant anthropometric data were recorded for analysis. PARTICIPANTS: 1218 pregnant women aged 18-42 years and their newborns. RESULTS: Prevalence of GA and SF depletion was 41·6 % and 41·1 %, respectively. GA was positively associated with poverty-related sociodemographic conditions. Prenatal care attendance lowered the risk of PB, LBW and SGA. Birth weight was inversely associated with Hb levels, observing a -36·8 g decrease in newborn weight per 0·62 mmol/l (or 1 g/dl) of maternal Hb. SF depletion, but not anaemia, was associated with PB. SGA outcome showed a significant association with anaemia, but not a significant relationship with SF depletion. CONCLUSIONS: Birth weight and other-related perinatal outcomes are negatively associated with Hb and SF depletion. Prenatal care attendance reduced the risk of negative birth outcomes.

Urinary bladder agenesis and renal hypoplasia potentially related to in utero Zika virus infection.

This case report describes the clinical findings of a 22-year-old pregnant woman with confirmed Zika virus infection, at 16 weeks of gestation, in Sucre, Colombia. Her ultrasound revealed severe oligohydramnios, intrauterine growth restriction, and a complete absence of the urinary bladder of the fetus. The poor prognosis led to the decision to terminate the pregnancy. Autopsy of the fetus revealed severe bilateral renal hypoplasia.

Neighborhood Violence Impacts Disease Control and Surveillance: Case Study of Cali, Colombia from 2014 to 2016.

Arboviruses are responsible for a large burden of disease globally and are thus subject to intense epidemiological scrutiny. However, a variable notably absent from most epidemiological analyses has been the impact of violence on arboviral transmission and surveillance. Violence impedes surveillance and delivery of health and preventative services and affects an individual's health-related behaviors when survival takes priority. Moreover, low and middle-income countries bear a disproportionately high burden of violence and related health outcomes, including vector borne diseases. To better understand the epidemiology of arboviral outbreaks in Cali, Colombia, we georeferenced chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viral cases from The National System of Surveillance in Public Health between October 2014 and April 2016. We extracted homicide data from the municipal monthly reports and kernel density of homicide distribution from IdeasPaz. Crucially, an overall higher risk of homicide is associated with increased risk of reported DENV, lower rates of acute testing, and higher rates of lab versus clinical discordance. In the context of high violence as a potential barrier to access to preventive health services, a community approach to improve health and peace should be considered.

αVß3 Integrin regulates astrocyte reactivity.

BACKGROUND: Neuroinflammation involves cytokine release, astrocyte reactivity and migration. Neuronal Thy-1 promotes DITNC1 astrocyte migration by engaging αVß3 Integrin and Syndecan-4. Primary astrocytes express low levels of these receptors and are unresponsive to Thy-1; thus, inflammation and astrocyte reactivity might be necessary for Thy-1-induced responses. METHODS: Wild-type rat astrocytes (TNF-activated) or from human SOD1G93A transgenic mice (a neurodegenerative disease model) were used to evaluate cell migration, Thy-1 receptor levels, signaling molecules, and reactivity markers. RESULTS: Thy-1 induced astrocyte migration only after TNF priming. Increased expression of αVß3 Integrin, Syndecan-4, P2X7R, Pannexin-1, Connexin-43, GFAP, and iNOS were observed in TNF-treated astrocytes. Silencing of ß3 Integrin prior to TNF treatment prevented Thy-1-induced migration, while ß3 Integrin over-expression was sufficient to induce astrocyte reactivity and allow Thy-1-induced migration. Finally, hSOD1G93A astrocytes behave as TNF-treated astrocytes since they were reactive and responsive to Thy-1. CONCLUSIONS: Therefore, inflammation induces expression of αVß3 Integrin and other proteins, astrocyte reactivity, and Thy-1 responsiveness. Importantly, ectopic control of ß3 Integrin levels modulates these responses regardless of inflammation.

Malaria epidemiology in low-endemicity areas of the northern coast of Ecuador: high prevalence of asymptomatic infections.

BACKGROUND: The recent scale-up in malaria control measures in Latin America has resulted in a significant decrease in the number of reported cases in several countries including Ecuador, where it presented a low malaria incidence in recent years (558 reported cases in 2015) with occasional outbreaks of both Plasmodium falciparum and Plasmodium vivax in the coastal and Amazonian regions. This success in malaria control in recent years has led Ecuador to transition its malaria policy from control to elimination. RESULTS: This study evaluated the general knowledge, attitude and practices (KAP) about malaria, as well as its prevalence in four communities of an endemic area in northwest Ecuador. A total of 258 interviews to assess KAP in the community indicated that most people in the study area have a basic knowledge about the disease but did not use to contribute to its control. Six hundred and forty-eight blood samples were collected and analysed by thick blood smear and real-time PCR. In addition, the distribution of the infections was mapped in the study communities. Although, no parasites were found by microscopy, by PCR the total malaria prevalence was 7.5% (6.9% P. vivax and 0.6% P. falciparum), much higher than expected and comparable to that reported in endemic areas of neighbouring countries with higher malaria transmission. Serology using ELISA and immunofluorescence indicated 27% respondents for P. vivax and 22% respondents for P. falciparum. CONCLUSIONS: Results suggest that despite a great malaria reduction in Ecuador, transition from control to elimination would demand further improvement in malaria diagnostics, including active case detection to identify and treat parasite asymptomatic carriers, as well as community participation in its elimination.

Malaria elimination challenges in Mesoamerica: evidence of submicroscopic malaria reservoirs in Guatemala.

BACKGROUND: Even though malaria incidence has decreased substantially in Guatemala since 2000, Guatemala remains one of the countries with the highest malaria transmission in Mesoamerica. Guatemala is committed to eliminating malaria as part of the initiative 'Elimination of Malaria in Mesoamerica and the Island of Hispaniola' (EMMIE); however, it is still in the control phase. During the past decade, the government strengthened malaria control activities including mass distribution of long-lasting insecticide-impregnated bed nets, early diagnosis and prompt treatment. This study aimed to determine the prevalence of malaria, including gametocytes, in three areas of Guatemala using active case detection (ACD) and quantitative polymerase chain reaction (qPCR). METHODS: Cross-sectional surveys were conducted in three departments with varying transmission intensities: Escuintla, Alta Verapaz and Zacapa. Blood samples from 706 volunteers were screened for malaria using microscopy and qPCR which was also used to determine the prevalence of gametocytes among infected individuals. Results were collected and analysed using REDCap and R Project, respectively. RESULTS: Malaria was diagnosed by microscopy in only 2.8 % (4/141) of the volunteers from Escuintla. By contrast, qPCR detected a prevalence of 7.1 % (10/141) in the same volunteers, 8.4 % (36/429) in Alta Verapaz, and 5.9 % (8/136) in Zacapa. Overall, 7.6 % (54/706) of the screened individuals were positive, with an average parasitaemia level of 40.2 parasites/µL (range 1-1133 parasites/µL) and 27.8 % carried mature gametocytes. Fifty-seven percent (31/54) of qPCR positive volunteers were asymptomatic and out of the 42.6 % of symptomatic individuals, only one had a positive microscopy result. CONCLUSIONS: This study found a considerable number of asymptomatic P. vivax infections that were mostly submicroscopic, of which, approximately one-quarter harboured mature gametocytes. This pattern is likely to contribute to maintaining transmission across the region. Robust surveillance systems, molecular diagnostic tests and tailored malaria detection activities for each endemic site may prove to be imperative in accelerating malaria elimination in Guatemala and possibly across all of Mesoamerica.

Integrin-mediated transactivation of P2X7R via hemichannel-dependent ATP release stimulates astrocyte migration.

Our previous reports indicate that ligand-induced αVß3 integrin and Syndecan-4 engagement increases focal adhesion formation and migration of astrocytes. Additionally, ligated integrins trigger ATP release through unknown mechanisms, activating P2X7 receptors (P2X7R), and the uptake of Ca(2+) to promote cell adhesion. However, whether the activation of P2X7R and ATP release are required for astrocyte migration and whether αVß3 integrin and Syndecan-4 receptors communicate with P2X7R via ATP remains unknown. Here, cells were stimulated with Thy-1, a reported αVß3 integrin and Syndecan-4 ligand. Results obtained indicate that ATP was released by Thy-1 upon integrin engagement and required the participation of phosphatidylinositol-3-kinase (PI3K), phospholipase-C gamma (PLCγ) and inositol trisphosphate (IP3) receptors (IP3R). IP3R activation leads to increased intracellular Ca(2+), hemichannel (Connexin-43 and Pannexin-1) opening, and ATP release. Moreover, silencing of the P2X7R or addition of hemichannel blockers precluded Thy-1-induced astrocyte migration. Finally, Thy-1 lacking the integrin-binding site did not stimulate ATP release, whereas Thy-1 mutated in the Syndecan-4-binding domain increased ATP release, albeit to a lesser extent and with delayed kinetics compared to wild-type Thy-1. Thus, hemichannels activated downstream of an αVß3 integrin-PI3K-PLCγ-IP3R pathway are responsible for Thy-1-induced, hemichannel-mediated and Syndecan-4-modulated ATP release that transactivates P2X7Rs to induce Ca(2+) entry. These findings uncover a hitherto unrecognized role for hemichannels in the regulation of astrocyte migration via P2X7R transactivation induced by integrin-mediated ATP release.

Características moleculares y susceptibilidada antibióticos de cepas de Staphylococcusaureus colonizantes de pacientes conpatologías nasales procedentes de Cartagena(Colombia), 2015: estudio observacional / Molecular characterization and antibiotic susceptibility of Staphylococcus aureus strains colonizing patients with nasal pathology from Cartagena (Colombia), 2015: observational study

Staphylococcus aureus es uno de los principales patógenos causantes deinfecciones tanto a nivel hospitalario como comunitario. El objetivo de este estudio fuedeterminar características moleculares y los perfiles de resistencia a antibióticos deaislamientos de Staphylococcus aureus colonizantes de pacientes con patología nasalatendidos en el servicio de Otorrinolaringología del Hospital Universitario del Caribede la ciudad de Cartagena, Colombia. Métodos: los aislamientos de Staphylococcusaureus obtenidos de pacientes colonizados fueron sometidos a extracción de ADNy ensayos de PCR para determinar la presencia de los genes mecA y lukS/F-PV.Se determinó la pertenencia de las cepas a los complejos clonales CC5 y CC8, y sedeterminaron las relaciones clonales de los aislamientos mediante análisis de PFGE.A las cepas SARM se les tipificó y sub-tipificó el casete cromosomal estafilocócicoSCCmec mediante PCR múltiple. Resultados: la prevalencia de colonización encontradapara Staphylococcus aureus fue 22.8% y 5.26% para SARM. Del total de aislamientosSARM, 33.3% estuvieron relacionados con el clon CC8-SARM-IVc y 22.28%con CC8-SARM-IVa. Los genes para la leucocidina PVL se identificaron en 66.7% deaislamientos SARM y 40% de aislamientos sensibles a meticilina (SASM)...

High prevalence of sub-microscopic infections in Colombia.

BACKGROUND: Malaria transmission in Latin America is typically characterized as hypo-endemic and unstable with ~170 million inhabitants at risk of malaria infection. Although Colombia has witnessed an important decrease in malaria transmission, the disease remains a public health problem with an estimated ~10 million people currently living in areas with malaria risk and ~61,000 cases reported in 2012. This study aimed to establish the malaria prevalence in three endemic regions of Colombia to aid in designing new interventions for malaria elimination. METHODS: A cross-sectional survey was conducted in three regions of Colombia with different malaria epidemiological profiles: Tierralta (Ta), Tumaco (Tu) and Buenaventura (Bv). The Annual Parasite Index (API) was 10.7, 6.9 and 3.1, respectively. Participants were asked to respond to a sociodemographic questionnaire and then were bled to determine the Duffy genotype and the prevalence of malaria infection by microscopy and quantitative real-time PCR (qPCR). RESULTS: The study was conducted between October 2011 and January 2012. Eight sentinel sites with 1,169 subjects from 267 households were included. The overall prevalence of sub-microscopic infections measured by thick blood smear (TBS) was 0.3% (n=4) whereas by qPCR it was 9.7% (n=113), with a greater proportion (13%) in 40-50 years old individuals. Furthermore, different regions displayed different prevalence of sub-microscopic infections: Bv 12%, Ta 15%, and Tu 4%. From these 113 samples (qPCR), 74% were positive for P. vivax and 22% for P. falciparum, and 4% were mixed infections, which correlates to the overall parasite prevalence in Colombia. This study showed that in the southern Pacific coast of Colombia (Bv and Tu), around 56% of the population have a Duffy-negative genotype, compared to the northern region (Ta) where the percentage of Duffy-negative genotype is around 3%. CONCLUSIONS: Sub-microscopic infections are prevalent across different regions in Colombia, particularly in areas with relatively low transmission intensity. The poor microscopy results suggest the need for more sensitive diagnostic tools for detection of sub-microscopic infections. This study underscores the importance of conducting active case surveillance to more accurately determine malaria incidence, and highlights the need for updating the malaria guidelines to track and treat sub-microscopic malaria infections.

The IgE response to Ascaris molecular components is associated with clinical indicators of asthma severity.

BACKGROUND: Asthma is a common chronic disease worldwide and Ascaris lumbricoides infection (ascariasis) is frequent in tropical regions. However, the effect of ascariasis on asthma severity has not been sufficiently explored. We sought to evaluate the influence of the IgE immune response to Ascaris extract and purified house dust mites (HDM) and Ascaris allergens on indicators of asthma severity in patients living in the tropics. METHODS: Asthmatic patients from Cartagena, Colombia were recruited. Clinical assessment included questionnaires, physical examination, allergy skin tests, spirometry, parasite stool examination and IgE antibody measurements. Asthma was diagnosed by a physician according to validated criteria. Indicators of severity were occurrence of severe dyspnea episodes, night awakenings events, > 4 emergency room (ER) visits and hospitalizations during the last year. Specific IgE to Der p 2, Ascaris spp., Blomia tropicalis and Dermatophagoides pteronyssinus extracts was determined by ImmunoCap. IgE to tropomyosins (Asc l 3, Blo t 10 and Der p 10), Blo t 5 and Asc s 1 was detected by ELISA. Logistic regression analyses were used to explore the relationships between sensitization and indicators of asthma severity. RESULTS: After adjustment for HDM sensitization, Ascaris sensitization remained associated with severe dyspnea (aOR: 1.90, 95% CI: 1.08 - 3.34, p = 0.03) and > 4 ER visits (aOR: 2.23, 95% CI: 1.15 - 4.30, p = 0.02). We also found that sensitization to the species specific markers Blo t 5 and Asc s 1, as well as the cross-reactive tropomyosins of D. pteronyssinus and Ascaris were associated with > 4 ER visits. Der p 2 sensitization was associated with bronchodilator responsiveness (aOR: 2.24: 1.25-4.02, p = 0.01). Remarkably, significantly higher IgE levels to HDM species specific allergens were found in Ascaris sensitized patients. CONCLUSIONS: In this tropical population, IgE sensitization to Ascaris and the cross-reactive tropomyosins was frequent and associated with clinical indicators of asthma severity. The significant relationship between sensitization to the nematode-specific marker Asc s 1 and ER attendance supports these findings. Moreover, ascariasis increases the human IgE responses to HDM specific allergens.

Malaria-related anemia in patients from unstable transmission areas in Colombia.

Information about the prevalence of malarial anemia in areas of low-malaria transmission intensity, like Latin America, is scarce. To characterize the malaria-related anemia, we evaluated 929 malaria patients from three sites in Colombia during 2011-2013. Plasmodium vivax was found to be the most prevalent species in Tierralta (92%), whereas P. falciparum was predominant in Tumaco (84%) and Quibdó (70%). Although severe anemia (hemoglobin < 7 g/dL) was almost absent (0.3%), variable degrees of non-severe anemia were observed in 36.9% of patients. In Tierralta, hemoglobin levels were negatively associated with days of illness. Moreover, in Tierralta and Quibdó, the number of previous malaria episodes and hemoglobin levels were positively associated. Both Plasmodium species seem to have similar potential to induce malarial anemia with distinct cofactors at each endemic setting. The target age in these low-transmission settings seems shifting toward adolescents and young adults. In addition, previous malaria experience seems to induce protection against anemia development. Altogether, these data suggest that early diagnosis and prompt treatment are likely preventing more frequent and serious malaria-related anemia in Colombia.

Anti-leishmanial evaluation of C2-aryl quinolines: mechanistic insight on bioenergetics and sterol biosynthetic pathway of Leishmania braziliensis.

A series of diverse simple C2-aryl quinolines was synthesized de novo via a straightforward synthesis based on the acid-catalyzed multicomponent imino Diels-Alder reactions. Seven selected quinolines were evaluated at different stages of Leishmania braziliensis parasite. Among them, the 6-ethyl-2-phenylquinoline 5f was able to inhibit the growth of promastigotes of this parasite without affecting the mammalian cells viability and decreasing the number of intracellular L. braziliensis amastigotes on BMDM macrophages. The mechanism of action studied for the selected compound consisted in: (1) alteration of parasite bioenergetics, by disrupting mitochondrial electrochemical potential and alkalinization of acidocalcisomes, and (2) inhibition of ergosterol biosynthetic pathway in promastigote forms. These results validate the efficiency of quinoline molecules as leishmanicide compounds.

Thy-1-mediated cell-cell contact induces astrocyte migration through the engagement of αVß3 integrin and syndecan-4.

Cell adhesion to the extracellular matrix proteins occurs through interactions with integrins that bind to Arg-Gly-Asp (RGD) tripeptides, and syndecan-4, which recognizes the heparin-binding domain of other proteins. Both receptors trigger signaling pathways, including those that activate RhoGTPases such as RhoA and Rac1. This sequence of events modulates cell adhesion to the ECM and cell migration. Using a neuron-astrocyte model, we have reported that the neuronal protein Thy-1 engages αVß3 integrin and syndecan-4 to induce RhoA activation and strong astrocyte adhesion to their underlying substrate. Thus, because cell-cell interactions and strong cell attachment to the matrix are considered antagonistic to cell migration, we hypothesized that Thy-1 stimulation of astrocytes should preclude cell migration. Here, we studied the effect of Thy-1 expressing neurons on astrocyte polarization and migration using a wound-healing assay and immunofluorescence analysis. Signaling molecules involved were studied by affinity precipitation, western blotting and the usage of specific antibodies. Intriguingly, Thy-1 interaction with its two receptors was found to increase astrocyte polarization and migration. The latter events required interactions of these receptors with both the RGD-like sequence and the heparin-binding domain of Thy-1. Additionally, prolonged Thy-1-receptor interactions inhibited RhoA activation while activating FAK, PI3K and Rac1. Therefore, sustained engagement of integrin and syndecan-4 with the neuronal surface protein Thy-1 induces astrocyte migration. Interestingly we identify here, a cell-cell interaction that despite initially inducing strong cell attachment, favors cell migration upon persistent stimulation by engaging the same signaling receptors and molecules as those utilized by the extracellular matrix proteins to stimulate cell movement.

Particular characteristics of allergic symptoms in tropical environments: follow up to 24 months in the FRAAT birth cohort study.

BACKGROUND: Early wheezing and asthma are relevant health problems in the tropics. Mite sensitization is an important risk factor, but the roles of others, inherent in poverty, are unknown. We designed a birth-cohort study in Cartagena (Colombia) to investigate genetic and environmental risk factors for asthma and atopy, considering as particular features perennial exposure to mites, parasite infections and poor living conditions. METHODS: Pregnant women representative of the low-income suburbs of the city were randomly screened for eligibility at delivery; 326 mother-infant pairs were included at baseline and biological samples were collected from birth to 24 months for immunological testing, molecular genetics and gene expression analysis. Pre and post-natal information was collected using questionnaires. RESULTS: 94% of families were from the poorest communes of the city, 40% lacked sewage and 11% tap-water. Intestinal parasites were found as early as 3 months; by the second year, 37.9% of children have had parasites and 5.22% detectable eggs of Ascaris lumbricoides in stools (Median 3458 epg, IQR 975-9256). The prevalence of "wheezing ever" was 17.5% at 6 months, 31.1% at 12 months and 38.3% at 24 months; and recurrent wheezing (3 or more episodes) 7.1% at 12 months and 14.2% at 24 months. Maternal rhinitis [aOR 3.03 (95%CI 1.60-5.74), p = 0.001] and male gender [aOR 2.09 (95%CI 1.09 - 4.01), p = 0.026], increased risk for wheezing at 6 months. At 24 months, maternal asthma was the main predisposing factor for wheezing [aOR 3.65 (95%CI 1.23-10.8), p = 0.01]. Clinical symptoms of milk/egg allergy or other food-induced allergies were scarce (1.8%) and no case of atopic eczema was observed. CONCLUSIONS: Wheezing is the most frequent phenotype during the first 24 months of life and is strongly associated with maternal asthma. At 24 months, the natural history of allergic symptoms is different to the "atopic march" described in some industrialized countries. This cohort is representative of socially deprived urban areas of underdeveloped tropical countries. The collection of biological samples, data on exposure and defined phenotypes, will contribute to understand the gene/environment interactions leading to allergy inception and evolution.

ATP release due to Thy-1-integrin binding induces P2X7-mediated calcium entry required for focal adhesion formation.

Thy-1, an abundant mammalian glycoprotein, interacts with αvß3 integrin and syndecan-4 in astrocytes and thus triggers signaling events that involve RhoA and its effector p160ROCK, thereby increasing astrocyte adhesion to the extracellular matrix. The signaling cascade includes calcium-dependent activation of protein kinase Cα upstream of Rho; however, what causes the intracellular calcium transients required to promote adhesion remains unclear. Purinergic P2X7 receptors are important for astrocyte function and form large non-selective cation pores upon binding to their ligand, ATP. Thus, we evaluated whether the intracellular calcium required for Thy-1-induced cell adhesion stems from influx mediated by ATP-activated P2X7 receptors. Results show that adhesion induced by the fusion protein Thy-1-Fc was preceded by both ATP release and sustained intracellular calcium elevation. Elimination of extracellular ATP with Apyrase, chelation of extracellular calcium with EGTA, or inhibition of P2X7 with oxidized ATP, all individually blocked intracellular calcium increase and Thy-1-stimulated adhesion. Moreover, Thy-1 mutated in the integrin-binding site did not trigger ATP release, and silencing of P2X7 with specific siRNA blocked Thy-1-induced adhesion. This study is the first to demonstrate a functional link between αvß3 integrin and P2X7 receptors, and to reveal an important, hitherto unanticipated, role for P2X7 in calcium-dependent signaling required for Thy-1-stimulated astrocyte adhesion.

High-frequency field stimulation of primary neurons enhances ryanodine receptor-mediated Ca2+ release and generates hydrogen peroxide, which jointly stimulate NF-κB activity.

Neuronal electrical activity increases intracellular Ca(2+) concentration and generates reactive oxygen species. Here, we show that high frequency field stimulation of primary hippocampal neurons generated Ca(2+) signals with an early and a late component, and promoted hydrogen peroxide generation via a neuronal NADPH oxidase. Hydrogen peroxide generation required both Ca(2+) entry through N-methyl-D-aspartate receptors and Ca(2+) release mediated by ryanodine receptors (RyR). Field stimulation also enhanced nuclear translocation of the NF-κB p65 protein and NF-κB -dependent transcription, and increased c-fos mRNA and type-2 RyR protein content. Preincubation with inhibitory ryanodine or with the antioxidant N-acetyl L-cysteine abolished the increase in hydrogen peroxide generation and the late Ca(2+) signal component induced by electrical stimulation. Primary cortical cells behaved similarly as primary hippocampal cells. Exogenous hydrogen peroxide also activated NF-κB-dependent transcription in hippocampal neurons; inhibitory ryanodine prevented this effect. Selective inhibition of the NADPH oxidase or N-acetyl L-cysteine also prevented the enhanced translocation of p65 in hippocampal cells, while N-acetyl L-cysteine abolished the increase in RyR2 protein content induced by high frequency stimulation. In conclusion, the present results show that electrical stimulation induced reciprocal activation of ryanodine receptor-mediated Ca(2+) signals and hydrogen peroxide generation, which stimulated jointly NF-κB activity.

Repercusión del miembro fantasma en la rehabilitación de pacientes amputados de miembros inferiores / Repercussion of the ghost extremity in the rehabilitation of lower limb amputees

Se realizó un estudio observacional descriptivo transversal sobre los fenómenos del miembro fantasma en pacientes amputados de miembros inferiores en el Hospital Docente Clínico-Quirúrgico Provincial Amalia Simoni de Camagüey, desde enero 2004 hasta diciembre 2008 para determinar la repercusión del mismo en su rehabilitación integral. El universo-muestra quedó constituido por 81 pacientes, mayores de 15 años, ambos sexos, por criterios de inclusión, exclusión y salida. Se utilizó encuesta de variables. Resultados: predominó el sexo masculino con 50 (61,7 por ciento) y la mayor frecuencia en el grupo de edad de 45 a 59 años: 28 (34,5 por ciento); prevaleció la sensación fantasma con 52 casos (64,2 por ciento); la causa traumática la más frecuente con 31 (38,3 por ciento); las mayores frecuencias estuvieron dadas por los horarios vespertinos y nocturnos con 32 (39,5 por ciento) y 25 (30,9 por ciento) respectivamente; se empleó la radiación infrarroja y los ejercicios en todos los pacientes; fue predominante la sensación fantasma con 41 casos, parte integrante de 63 pacientes (77,8 por ciento) del total que obtuvo su rehabilitación. Se logró evitar una desfavorable repercusión del fenómeno fantasma como complicación en los amputados de miembros inferiores al obtenerse una rehabilitación integral superior al 77 por ciento(AU)

A cross-sectional descriptive observational study was carried out on the phenomena of the ghost extremity of lower limb amputees in Amalia Simoni Clinical and Surgical Teaching Hospital, Camagüey, from January 2004 to December 2008 to determine its repercussion in the integral rehabilitation. The universe of study was made up of the patients older than 15 years, both sex, with confirmed main diagnosis and complication. Inclusion/exclusion and exit criteria were applied to 81 patients (sample). A survey, which considered the variables: age; sex; type of sensation, etiology and level of amputation; occurrence schedule and beginning of the phenomenon; physiotherapeutic techniques used; and integral rehabilitation, was carried out to collect data. Results: masculine sex was the most prominent with 50 (61.7 percent) and the greatest frequency was in the age group from 45 to 59 years: 28 (34.5 percent); the ghost sensation predominated with 52 cases (64.2 percent); the traumatic cause with 31 (38.3 percent)was the most frequent; the highest frequencies were in the afternoon and night schedules with 32 (39.5 percent) and 25 (30.9 percent) respectively; the infrared radiation and the exercises were applied to all the patients; the ghost sensation with 41 cases was predominant, integral part of 63 patients (77.8 percent) of the total who obtained their rehabilitation. It is concluded that the avoidance of the unfavorable repercussion of the ghost phenomenon, as a complication of the lower limb amputees, was achieved, obtaining a higher- to-77 percent integral rehabilitation(AU)

Repercusión del miembro fantasma en la rehabilitación de pacientes amputados de miembros inferiores / Repercussion of the ghost extremity in the rehabilitation of lower limb amputees

Se realizó un estudio observacional descriptivo transversal sobre los fenómenos del miembro fantasma en pacientes amputados de miembros inferiores en el Hospital Docente Clínico-Quirúrgico Provincial Amalia Simoni de Camagüey, desde enero 2004 hasta diciembre 2008 para determinar la repercusión del mismo en su rehabilitación integral. El universo-muestra quedó constituido por 81 pacientes, mayores de 15 años, ambos sexos, por criterios de inclusión, exclusión y salida. Se utilizó encuesta de variables. Resultados: predominó el sexo masculino con 50 (61,7 por ciento) y la mayor frecuencia en el grupo de edad de 45 a 59 años: 28 (34,5 por ciento); prevaleció la sensación fantasma con 52 casos (64,2 por ciento); la causa traumática la más frecuente con 31 (38,3 por ciento); las mayores frecuencias estuvieron dadas por los horarios vespertinos y nocturnos con 32 (39,5 por ciento) y 25 (30,9 por ciento) respectivamente; se empleó la radiación infrarroja y los ejercicios en todos los pacientes; fue predominante la sensación fantasma con 41 casos, parte integrante de 63 pacientes (77,8 por ciento) del total que obtuvo su rehabilitación. Se logró evitar una desfavorable repercusión del fenómeno fantasma como complicación en los amputados de miembros inferiores al obtenerse una rehabilitación integral superior al 77 por ciento.

A cross-sectional descriptive observational study was carried out on the phenomena of the ghost extremity of lower limb amputees in Amalia Simoni Clinical and Surgical Teaching Hospital, Camagüey, from January 2004 to December 2008 to determine its repercussion in the integral rehabilitation. The universe of study was made up of the patients older than 15 years, both sex, with confirmed main diagnosis and complication. Inclusion/exclusion and exit criteria were applied to 81 patients (sample). A survey, which considered the variables: age; sex; type of sensation, etiology and level of amputation; occurrence schedule and beginning of the phenomenon; physiotherapeutic techniques used; and integral rehabilitation, was carried out to collect data. Results: masculine sex was the most prominent with 50 (61.7 percent) and the greatest frequency was in the age group from 45 to 59 years: 28 (34.5 percent); the ghost sensation predominated with 52 cases (64.2 percent); the traumatic cause with 31 (38.3 percent)was the most frequent; the highest frequencies were in the afternoon and night schedules with 32 (39.5 percent) and 25 (30.9 percent) respectively; the infrared radiation and the exercises were applied to all the patients; the ghost sensation with 41 cases was predominant, integral part of 63 patients (77.8 percent) of the total who obtained their rehabilitation. It is concluded that the avoidance of the unfavorable repercussion of the ghost phenomenon, as a complication of the lower limb amputees, was achieved, obtaining a higher- to-77 percent integral rehabilitation.

Increased hippocampal expression of the divalent metal transporter 1 (DMT1) mRNA variants 1B and +IRE and DMT1 protein after NMDA-receptor stimulation or spatial memory training.

Iron is essential for crucial neuronal functions but is also highly toxic in excess. Neurons acquire iron through transferrin receptor-mediated endocytosis and via the divalent metal transporter 1 (DMT1). The N-terminus (1A, 1B) and C-terminus (+IRE, -IRE) splice variants of DMT1 originate four protein isoforms, all of which supply iron to cells. Diverse physiological or pathological conditions induce differential DMT1 variant expression, which are cell-type dependent. Hence, it becomes relevant to ascertain if activation of neuronal plasticity processes that require functional N-methyl D: -aspartate (NMDA) receptors, including in vitro stimulation of NMDA receptor-mediated signaling and spatial memory training, selectively modify DMT1 variant expression. Here, we report for the first time that brief (5 min) exposure of primary hippocampal cultures to NMDA (50 muM) increased 24 h later the expression of DMT1-1B and DMT1+IRE, but not of DMT1-IRE mRNA. In contrast, endogenous DMT1 mRNA levels remained unaffected following 6 h incubation with brain-derived nerve factor. NMDA (25-50 muM) also enhanced DMT1 protein expression 24-48 h later; this enhancement was abolished by the transcription inhibitor actinomycin D and by the NMDA receptor antagonist MK-801, implicating NMDA receptors in de novo DMT1 expression. Additionally, spatial memory training enhanced DMT1-1B and DMT1+IRE expression and increased DMT1 protein content in rat hippocampus, where the exon1A variant was not found. These results suggest that NMDA receptor-dependent plasticity processes stimulate expression of the iron transporter DMT1-1B+IRE isoform, which presumably plays a significant role in hippocampal spatial memory formation.