Effects of PM10 Airborne Particles from Different Regions of a Megacity on In Vitro Secretion of Cytokines by a Monocyte Line during Different Seasons.

Several epidemiological studies have demonstrated that particulate matter (PM) in air pollution can be involved in the genesis or aggravation of different cardiovascular, respiratory, perinatal, and cancer diseases. This study assessed the in vitro effects of PM10 on the secretion of cytokines by a human monocytic cell line (THP-1). We compared the chemotactic, pro-inflammatory, and anti-inflammatory cytokines induced by PM10 collected for two years during three different seasons in five different Mexico City locations. MIP-1α, IP-10, MCP-1, TNF-α, and VEGF were the main secretion products after stimulation with 80 µg/mL of PM10 for 24 h. The THP-1 cells showed a differential response to PM10 obtained in the different sites of Mexico City. The PM10 from the north and the central city areas induced a higher pro-inflammatory cytokine response than those from the south. Seasonal pro-inflammatory cytokine secretion always exceeded anti-inflammatory secretion. The rainy-season-derived particles caused the lowest pro-inflammatory effects. We concluded that toxicological assessment of airborne particles provides evidence supporting their potential role in the chronic exacerbation of local or systemic inflammatory responses that may worsen the evolution of some chronic diseases.

Effects of Cryopreservation on Cell Metabolic Activity and Function of Biofabricated Structures Laden with Osteoblasts.

Biofabrication and maturation of bone constructs is a long-term task that requires a high degree of specialization. This specialization falls onto the hierarchy complexity of the bone tissue that limits the transfer of this technology to the clinic. This work studied the effects of the short-term cryopreservation on biofabricated osteoblast-containing structures, with the final aim to make them steadily available in biobanks. The biological responses studied include the osteoblast post-thawing metabolic activity and the recovery of the osteoblastic function of 3D-bioprinted osteoblastic structures and beta tricalcium phosphate (ß-TCP) scaffolds infiltrated with osteoblasts encapsulated in a hydrogel. The obtained structures were cryopreserved at -80 °C for 7 days using dimethyl sulfoxide (DMSO) as cryoprotectant additive. After thawing the structures were cultured up to 14 days. The results revealed fundamental biological aspects for the successful cryopreservation of osteoblast constructs. In summary, immature osteoblasts take longer to recover than mature osteoblasts. The pre-cryopreservation culture period had an important effect on the metabolic activity and function maintain, faster recovering normal values when cryopreserved after longer-term culture (7 days). The use of ß-TCP scaffolds further improved the osteoblast survival after cryopreservation, resulting in similar levels of alkaline phosphatase activity in comparison with the non-preserved structures. These results contribute to the understanding of the biology of cryopreserved osteoblast constructs, approaching biofabrication to the clinical practice.

Histological Transformation to Small Cell Carcinoma of an Adenosquamous Carcinoma of the Lung With Epidermal Growth Factor Receptor Mutation in Exons 20 and 21 After Treatment With Erlotinib: Case Report.

Lung carcinoma currently represents 1 of the leading causes of death from cancer worldwide and regionally. The molecular identification of sensitive mutations of targeted treatment have changed the strategies of pharmacologic management in non-small cell lung carcinoma. However, mechanisms of resistance have been described, among them the change of histological type to small cell carcinoma. We present the case of a 46-year-old male patient, non-smoker, with a clinical history of a mass in the upper lobe of the right lung and an initial histological diagnosis of adenosquamous carcinoma of the lung, with the presence of mutations for epidermal growth factor receptor (EGFR) in exons 20 (S768I) and 21 (L858R). He received treatment with tyrosine kinase inhibitor (Erlotinib) with good clinical and radiological response. However, 1 year after the start of the medication, he consulted for a progressive onset of constitutional symptoms and respiratory symptoms, with radiographic worsening and new biopsy with a diagnosis of adenosquamous carcinoma with the adenocarcinoma component transformed to small cell carcinoma, with persistence of EGFR mutation. We describe the clinical, radiological, and laboratory characteristics as well as the outcome of this case. To conclude, among the mechanisms of resistance described to the treatment with tyrosine kinase inhibitors in patients with carcinomas with mutated EGFR, the transformation to small cell carcinoma besides being infrequent is particular, requiring a different diagnostic and therapeutic approach.

"My Partner Will Change": Cognitive Distortion in Battered Women in Bolivia.

This study examines the role of cognitive distortion in women's decision to stay with or leave their violent partner in a sample of Bolivian women. Our study is based on a consistency model: Cognitive distortion is assumed to play an important role in maintaining cognitive consistency under threatening conditions. Eighty victims of partner violence aged 18 to 62 years who sought help in a legal institution were longitudinally assessed three times over a time period of 6 months. Measures were taken from previous studies and culturally adapted through qualitative interviews. Nearly half of the participants decreased their intention to leave the violent partner in the time span of 1 month between the first and second interview. Women who had decreased their leaving intention had concurrently increased their cognitive distortion: They blamed their partner less, were more convinced that they could stop the violence themselves, and were more likely to believe that their partner would change. Cognitive distortion was not observed among women who remained stable in their intention to leave. Women whose intention of leaving decreased and who displayed more cognitive distortion after 1 month were more likely to live with the violent partner 6 months later than women whose leaving intention remained stable or increased. Socio-demographic variables were not related to cognitive distortion or stay-leave decisions in this study. We conclude that cognitive distortion plays a role for women's decision to stay, enhancing their risk of re-victimization.

Gene Therapy for Treatment of Chronic Hyperammonemia in a Rat Model of Hepatic Encephalopathy.

INTRODUCTION AND AIM: Hepatic encephalopathy (HE), caused by hyperammonemia resulting from liver disease, is a spectrum of neuropsychiatric and motor disorders that can lead to death. Existing therapies are deficient and alternative treatments are needed. We have shown that gene therapy with a baculovirus vector containing the glutamine synthetase (Bac-GS) gene is efficient for reducing ammonia levels in an acute hyperammonemia rat model. However, the most common condition resulting from liver disease is chronic hyperammonemia. In this work, Bac-GS was evaluated in bile-duct ligated rats, a chronic liver disease model with hyperammonemia and some characteristics of Type C HE. MATERIAL AND METHODS: Bac-GS was tested for mediating GS overexpression in HeLa cells and H9C2 myotubes. For determining the utility of Bac-GS for the reduction of ammonia levels in a chronic hyperammonemia animal model, four groups of rats were treated: control, sham, ligated with Bac-GS and ligated with Bac-GFP. Baculoviruses were injected i.m. 18 days post-surgery. Blood was drawn 2, 3 and 4 weeks post-surgery and plasma ammonia concentrations were quantified. RESULTS: In protein lysates of cells and myotubes transduced with Bac-GS, a 44 kDa band corresponding to GS was detected. Significant results were obtained in the hyperammonemic bile-duct ligated rat model, as plasma ammonia was reduced to normal levels 3 days after treatment with Bac-GS. Furthermore, a transitory effect of Bac-GS was observed. CONCLUSION: Our results show that gene therapy by delivering GS is a promising alternative for treatment of hyperammonemia in acute-on-chronic liver failure patients with HE.

Particulate matter promotes in vitro receptor-recognizable low-density lipoprotein oxidation and dysfunction of lipid receptors.

Particulate matter may promote cardiovascular disease, possibly as a consequence of its oxidative potential. Studies using susceptible animals indicate that particulate matter aggravates atherosclerosis by increasing lipid/macrophage content in plaques. Macrophage lipid uptake requires oxidized low-density lipoprotein and scavenger receptors; same receptors are involved in particulate matter uptake. We studied in vitro particulate matter potential to oxidize low-density lipoproteins and subsequent cell uptake through scavenger receptors. Particulate matter-induced low-density lipoproteins oxidation was evaluated by the thiobarbituric acid assay. Binding/internalization was tested in wild type and scavenger receptor-transfected Chinese hamster ovary cells, and in RAW264.7 cells using fluorescently labeled low-density lipoproteins. Dose-dependent binding/internalization only occurred in scavenger receptor-transfected Chinese hamster ovary cells and RAW264.7 cells. Competition binding/internalization using particles showed that particulate matter induced decreased binding (∼50%) and internalization (∼70%) of particle-oxidized low-density lipoproteins and native low-density lipoproteins. Results indicate that particulate matter was capable of oxidizing low-density lipoproteins, favoring macrophage internalization, and also altered scavenger and low-density lipoproteins receptor function.

Improved diagnosis of Strongyloides stercoralis using recombinant antigen-based serologies in a community-wide study in northern Argentina.

The serodiagnosis of Strongyloides stercoralis infection by enzyme-linked immunosorbent assays based on crude antigen (CrAg-ELISA), while useful, has been limited by the reliance on crude parasite extracts. Newer techniques such as the luciferase immunoprecipitation system assay (LIPS), based on a 31-kDa recombinant antigen (termed NIE) from S. stercoralis and/or the recombinant antigen S. stercoralis immunoreactive antigen (SsIR), or the NIE-ELISA have shown promise in controlled settings. We compared each of these serologic assays in individuals from both regions of the world in which S. stercoralis is endemic and those in which it is not. A comprehensive stool evaluation (sedimentation concentration, Baermann concentration with charcoal cultures, agar plate, and Harada-Mori) and four different serologic techniques using CrAg-ELISA or recombinant NIE-ELISA as well as LIPS using NIE alone or in combination with a second recombinant antigen (NIE/SsIR-LIPS) were compared among individuals with parasitologically proven infection (n = 251) and healthy controls from regions of the world in which the infection is nonendemic (n = 11). Accuracy was calculated for each assay. The prevalence of S. stercoralis infection was 29.4% among Argentinean stool samples (n = 228). Sedimentation concentration and Baermann were the most sensitive stool-based methods. NIE-LIPS showed the highest sensitivity (97.8%) and specificity (100%) of the serologic assays. The calculated negative predictive value was highest for both the NIE-LIPS and CrAg-ELISA (>97%) irrespective of disease prevalence. No cross-reactivity with soil-transmitted helminths was noted. NIE-LIPS compares favorably against the current CrAg-ELISA and stool evaluation, providing additional accuracy and ease of performance in the serodiagnosis of S. stercoralis infections irrespective of disease prevalence.

Calidad de red como variable moduladora de depresión en adolescentes estudiantes de nivel medio / Quality network as moderator variable of depression in teenagers high school students

En un estudio previo (Nava & Vega, 2008) quisimos probar si alguna alteración emocional (depresión) podía ser atribuida a la lejanía de la red familiar, los análisis mostraron que sí era posible encontrar diferencias entre jóvenes recluidos y estudiantes universitarios. Sin embargo, los resultados del estudio anterior dejaban una duda, ¿sería posible encontrar depresión aun cuando no hay ausencia de familia de origen? Y, ¿qué variables explicarían tal fenómeno, en caso de encontrar diferencias? Por lo anterior, decidimos realizar un estudio en el cual los participantes fueran adolescentes sin ninguna carencia de familia o alteración psicológica aparente. Evaluamos diferentes variables: apoyo social, estrés, calidad de red y depresión. Los resultados mostraron que sí fue posible replicar los resultados del primer estudio, a pesar de que no existieron alteraciones emocionales o de red graves. Las conclusiones son discutidas a la luz de los hallazgos empíricos y teóricos correspondientes.

In a previous study (Nava & Vega, 2008) we wanted to prove if some emotional alterations (depression) could be attributed to the remoteness of the family network, the analyses showed that it was possible to find differences between young adults to imprison and university students. Nevertheless, the results of the previous study left a doubt, would it be possible to find depression even though there is no absence of origin of family? And what variable would explain such phenomenon, in case of finding differences? By the previous thing, we decided to make a study where the participants were adolescents without deficiency of family or apparent psychological alteration. We evaluated different variables, social support, stress, quality of network and depression. The results showed that it was possible to talk back the results of the first study, although emotional alterations or of network did not exist seriously. The conclusions are discussed to the light of the empirical and theoretical findings.

Preconditioning stimuli that augment chromaffin cell secretion.

We have investigated here whether a preconditioned stimulation of nicotinic and muscarinic receptors augmented the catecholamine release responses elicited by supramaximal 3-s pulses of 100 muM acetylcholine (100ACh) or 100 mM K(+) (100K(+)) applied to fast-perifused bovine adrenal chromaffin cells. Threshold concentrations of nicotine (1-3 muM) that caused only a tiny secretion did, however, augment the responses elicited by 100ACh or 100K(+) by 2- to 3.5-fold. This effect was suppressed by mecamylamine and by Ca(2+) deprivation, was developed with a half-time (t(1/2)) of 1 min, and was reversible. The nicotine effect was mimicked by threshold concentrations of ACh, choline, epibatidine, and oxotremorine-M but not by methacholine. Threshold concentrations of K(+) caused lesser potentiation of secretion compared with that of threshold nicotine. The data are compatible with an hypothesis implying 1) that continuous low-frequency sympathetic discharge places chromaffin cells at the adrenal gland in a permanent "hypersensitive" state; and 2) this allows an explosive secretion of catecholamines by high-frequency sympathetic discharge during stress.

A low nicotine concentration augments vesicle motion and exocytosis triggered by K(+) depolarisation of chromaffin cells.

Tobacco smokers have an increased risk of cardiovascular disease; this is likely associated to an enhanced catecholamine release by circulating nicotine. Here, we have explored how low concentrations of nicotine in the range of those found in the blood of tobacco smokers, might affect the release of catecholamines in bovine chromaffin cells. We have combined patch-clamp and Ca(2+) imaging techniques to study cell excitability, cytosolic Ca(2+) transients, vesicle movement, and secretory responses. We found that low concentrations of nicotine (1.5-3 microM) did not enhance catecholamine release by themselves. However, they drastically augmented the catecholamine release response triggered by a supramaximal K(+) depolarising pulse. Furthermore, low nicotine concentrations caused slight depolarisation with superimposed action potentials, a transient elevation of [Ca(2+)](c) and augmented Ca(2+)-dependent vesicle motion underneath the plasmalemma. We suggest that low nicotine concentrations overload the secretory machinery with secretory vesicles, which cause chromaffin cells to respond with an exaggerated adrenaline release into the circulation during stress. This might contribute to the higher cardiovascular risk of tobacco smokers.

Enhancement of secretion by threshold nicotinic stimulation in bovine chromaffin cells.

Synaptic release of neurotransmitters displays activity-dependent changes such as enhancement (facilitation, augmentation, or potentiation) or diminution (depression), which have been studied widely because of their implication in synaptic efficacy, neuronal plasticity, and formation and consolidation of learning and memory. Some of these types of modulation of secretion displayed by neurons are also present in neuroendocrine chromaffin cells, for instance, facilitation or augmentation, which seem to be related to mild changes in the transients of cytosolic concentration of calcium ([Ca2+]i) and the degree of refilling of the primed vesicle pool (Zucker, 1996; Neher, 1998). Desensitized nicotinic acetylcholine receptors (nAChRs) and their possible role in this short-term synaptic plasticity was investigated in populations of bovine chromaffin cells.

Activation and blockade by choline of bovine alpha7 and alpha3beta4 nicotinic receptors expressed in oocytes.

Choline, the precursor and the metabolite of acetylcholine, is reputed as a selective alpha7 nicotinic receptor agonist. In this study, however, we have seen that choline exerted a dual effect on bovine nicotinic receptors expressed in Xenopus oocytes. On the one hand, choline behaved as a weak full agonist on bovine alpha7-mediated inward currents, with an EC50 of 0.43 mM. On the other, choline blocked bovine alpha3beta4 currents, with an IC50 of 0.97 mM. The blockade by choline was fast (tau(on), 0.36 s), fully reversible (tau(off), 1.23 s), exhibited voltage-dependence (60% blockade at -100 mV and 30% blockade at -40 mV), and was of a non-competitive nature, suggesting an open-channel type of alpha3beta4 receptor blockade. Thus, choline by activating alpha7 receptors and/or blocking alpha3beta4 receptors might play a physiological role in the control of neurotransmission at cholinergic synapses where alpha7 and alpha3beta4 receptor are expressed.

A choline-evoked [Ca2+]c signal causes catecholamine release and hyperpolarization of chromaffin cells.

In bovine chromaffin cells fast-superfused with Krebs-HEPES solution containing 1-2 mM Ca2+, 5 s pulses of choline (1-10 mM), elicited catecholamine secretory responses that were only approximately 10% of those evoked by ACh (0.01-0.1 mM). However, in high-Ca2+ solutions (10-20 mM) the size of the choline secretory responses approached those of ACh. The choline responses (10 mM choline in 20 mM Ca2+, 10Cho/20Ca2+) tended to decline upon repetitive pulsing, whereas those of ACh were well maintained. The confocal [Ca2+]c increases evoked by 10Cho/20Ca2+ were similar to those of ACh. Whereas 10Cho/20Ca2+ caused mostly hyperpolarization of chromaffin cells, 0.1ACh/20 Ca2+ caused first depolarization and then hyperpolarization; in regular solutions (2 mM Ca2+), the hyperpolarizing responses did not show up. In Xenopus oocytes injected with mRNA for bovine alpha7 nicotinic receptors (nAChRs), 10Cho/20 Ca2+ fully activated an inward current; in oocytes expressing alpha3beta4, however, the inward current elicited by choline amounted to only 4% of the size of alpha7 current. Our results suggest that choline activates the entry of Ca2+ through alpha7 nAChRs; this leads to a cytosolic concentration of calcium ([Ca2+]c) rise that causes the activation of nearby Ca2+-dependent K+ channels and the hyperpolarization of the chromaffin cell. This response, which could be unmasked provided that cells were stimulated with high-Ca2+ solutions, may be the underlying mechanism through which choline exerts a modulatory effect on the electrical activity of the chromaffin cell and on neurotransmitter release at cholinergic synapses.