Analysis of cholesterol-recognition motifs of the plasma membrane Ca2+-ATPase.

The plasma membrane Ca2+-ATPase (PMCA) is crucial for the fine tuning of intracellular calcium levels in eukaryotic cells. In this study, we show the presence of CARC sequences in all human and rat PMCA isoforms and we performed further analysis by molecular dynamics simulations. This analysis focuses on PMCA1, containing three CARC motifs, and PMCA4, with four CARC domains. In PMCA1, two CARC motifs reside within transmembrane domains, while the third is situated at the intracellular interface. The simulations depict more stable RMSD values and lower RMSF fluctuations in the presence of cholesterol, emphasizing its potential stabilizing effect. In PMCA4, a distinct dynamic was found. Notably, the total energy differences between simulations with cholesterol and phospholipids are pronounced in PMCA4 compared to PMCA1. RMSD values for PMCA4 indicate a more energetically favorable conformation in the presence of cholesterol, suggesting a robust interaction between CARCs and this lipid in the membranes. Furthermore, RMSF analysis for CARCs in both PMCA isoforms exhibit lower values in the presence of cholesterol compared to POPC alone. The analysis of H-bond occupancy and total energy values strongly suggests the potential interaction of CARCs with cholesterol. Given the crucial role of PMCAs in physiological calcium regulation and their involvement in diverse pathological processes, this study underscores the significance of CARC motifs and their interaction with cholesterol in elucidating PMCA function. These insights into the energetic preferences associated with CARC-cholesterol interactions offer valuable implications for understanding PMCA function in maintaining calcium homeostasis and addressing potential associated pathologies.

ATR1 A1166C (rs5186), FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016) and MTHFR A1298C (rs1801131) polymorphisms and the risk of ST-elevation myocardial infarction in young Mexican individuals.

BACKGROUND: Previous studies had identified genetic variants associated with Myocardial Infarction, but results are inconclusive. We examined the association between FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016), ATR1 A1166C (rs5186) and MTHFR A1298C (rs1801131) polymorphisms and ST elevation Myocardial Infarction in young Mexican individuals. METHODS: We included a total of 350 patients with Myocardial Infarction <45 years old and 350 controls matched by age and gender. The polymorphisms were analyzed by PCR-RFLP using specific restriction enzymes. DNA fragments were separated by electrophoresis in 2% gel of agarose and visualized using SYBR green. RESULTS: The A1166C (p = 0.004) but not FXIII 97G > T (p = 0.19), G20210A (p = 0.32), G1691A (p = No significant) and A1298C (p = 0.21) polymorphisms were associated with increased risk for ST elevation Myocardial Infarction. Moreover, dyslipidemia, hypertension, smoking and family history of atherothrombotic disease were associated. CONCLUSIONS: We found that A1166C represented increased risk for ST elevation Myocardial Infarction. However, G20210A, G1691A, 97G > T, and A1298C were not associated. In addition, we had determined that Glu298Asp, PLA1/A2, TAFI Thr325Ile, ACE I/D, AGT M235T and PAI-1 4G/5G polymorphisms represented increased risk in the same group of patients. However, MTHFR C677T, AGT T174M, FV G1691A, TSP-1 N700S, MTHFR C677T and TAFI 174 M polymorphisms were no associated. Our results suggest that in young patients with ST Myocardial Infarction, those polymorphisms could contribute to premature endothelial dysfunction, atherothrombosis, vasoconstriction, increased platelet aggregation, muscle cell migration and proliferation. Further studies are required to try to better assess gene-gene and gene-modifiable factors interaction.

The cholesteryl-ester transfer protein isoform (CETPI) and derived peptides: new targets in the study of Gram-negative sepsis.

BACKGROUND: Sepsis is a syndrome where the dysregulated host response to infection threatens the life of the patient. The isoform of the cholesteryl-ester transfer protein (CETPI) is synthesized in the small intestine, and it is present in human plasma. CETPI and peptides derived from its C-terminal sequence present the ability to bind and deactivate bacterial lipopolysaccharides (LPS). The present study establishes the relationship between the plasma levels of CETPI and disease severity of sepsis due to Gram-negative bacteria. METHODS: Plasma samples from healthy subjects and patients with positive blood culture for Gram-negative bacteria were collected at the Intensive Care Unit (ICU) of INCMNSZ (Mexico City). 47 healthy subjects, 50 patients with infection, and 55 patients with sepsis and septic shock, were enrolled in this study. CETPI plasma levels were measured by an enzyme-linked immunosorbent assay and its expression confirmed by Western Blot analysis. Plasma cytokines (IL-1ß, TNFα, IL-6, IL-8, IL-12p70, IFNγ, and IL-10) were measured in both, healthy subjects, and patients, and directly correlated with their CETPI plasma levels and severity of clinical parameters. Sequential Organ Failure Assessment (SOFA) scores were evaluated at ICU admission and within 24 h of admission. Plasma LPS and CETPI levels were also measured and studied in patients  with liver dysfunction. RESULTS: The level of CETPI in plasma was found to be higher in patients with positive blood culture for Gram-negative bacteria that in control subjects, showing a direct correlation with their SOFA values. Accordingly, septic shock patients showing a high CETPI plasma concentration, presented a negative correlation with cytokines IL-8, IL-1ß, and IL-10. Also, in patients  with liver dysfunction, since higher CETPI levels correlated with a high plasma LPS concentration, LPS neutralization carried out by CETPI might be considered a physiological response that will have to be studied in detail. CONCLUSIONS: Elevated levels of plasma CETPI were associated with disease severity and organ failure in patients  with Gram-negative bacteraemia, defining CETPI as a protein implicated in the systemic response to LPS.

Soluble Endoglin and Uterine Artery Flow Doppler Ultrasonography as Markers of Progression to Preeclampsia in Women with Gestational Hypertension.

INTRODUCTION: Gestational hypertension (GH) pregnancies are at a high risk of developing adverse outcomes, including progression to preeclampsia. Prediction of GH-related adverse outcomes is challenging because there are no available clinical tests that may predict their occurrence. OBJECTIVE: The aim of the study was to determine the clinical usefulness of the soluble endoglin (sEng) and parameters of uterine artery flow (UtAF) measured by Doppler ultrasonography as markers of progression to preeclampsia in women with GH. SETTING: Mexico City, Mexico. MATERIAL AND METHODS: We included 77 singleton pregnant women with GH in a nested case-control study. Cases were women who progressed to preeclampsia (n = 36), and controls were those who did not (n = 41). Serum sEng and UtAF measurements were performed at enrollment. The main outcomes measured were progression to preeclampsia and occurrence of preterm delivery (PD) <37 and <34 weeks of gestation, small for gestational age infant (SGA), and fetal growth restriction (FGR). RESULTS: Women with sEng values in the highest tertile had higher risk of progression to preeclampsia, preterm delivery <34 weeks of gestation, and fetal growth restriction, odds ratios (ORs) ≥3.7. Patients with abnormal UtAF Dopp-ler-pulsatility index had higher risk of progression to preeclampsia, preterm delivery <34 weeks of gestation, small for gestational age infant, and fetal growth restriction (ORs ≥3.3). The presence of notch was associated with higher risk of progression to preeclampsia, preterm delivery <37 and <34 weeks of gestation, SGA infant, and fetal growth restriction (ORs ≥2.9). However, logistic regression analysis revealed that only serum sEng was a significant and independent risk factor for progression of GH to preeclampsia, preterm delivery <34 weeks of gestation, and fetal growth restriction (ORs ≥3.1). CONCLUSIONS: In GH pregnancies, UtAF Doppler ultrasonography is associated with increased risk of adverse outcomes and progression to preeclampsia. However, serum sEng concentration appears to be a better predictor to assess the risk of adverse maternal and perinatal outcomes and progression to preeclampsia.

Interleukin-6 in Amniotic Fluid: A Reliable Marker for Adverse Outcomes in Women in Preterm Labor and Intact Membranes.

INTRODUCTION: Amniotic fluid (AF) interleukin-6 (IL-6) concentration has been associated to preterm delivery and perinatal morbidity and mortality in women with preterm labor and intact membranes. Nevertheless, the clinical significance of this biomarker of intra-amniotic inflammation (IAI) is still unclear due in part to the paucity of large studies. METHODS: AF IL-6 concentrations were determined in 452 consecutive women with preterm labor and intact membranes, categorized into 3 groups: 302 without IAI (IL-6 of <2.6 ng/mL), 64 with mild IAI (IL-6 of 2.6-11.2 ng/mL), and 86 with severe IAI (IL-6 of ≥11.3 ng/mL). RESULTS: The severe IAI group had a short pregnancy duration from amniocentesis to delivery (median 3 days) than in without IAI group (median 45 days); meanwhile, the mild IAI group had a latency that was intermediate to the severe and without IAI groups (median 9.5 days). As compared to women without IAI, women with mild and severe IAI had higher rates of preterm delivery at both <34 and <37 weeks of gestation and perinatal morbidity and mortality. Furthermore, the risk of various individual adverse outcomes (short latency from amniocentesis to delivery [at ≤3 days, ≤7 days, and ≤14 days], preterm delivery at both <34 and <37 weeks of gestation, histologic chorioamnionitis, respiratory distress syndrome, and congenital sepsis) was higher in women with severe IAI (OR ≥ 2.8), compared with women without IAI. CONCLUSIONS: AF IL-6 concentrations appear to be suitable marker to assess the degree of IAI and are associated with increased risk of adverse outcomes.

Factors related to changes in the asthma male: female ratio by age in 403 Mexican counties.

BACKGROUND: Asthma is more frequent in males during childhood and in females after adolescence, which has been attributed to changes in sexual hormones levels. OBJECTIVE: We explored changes of the asthma male: female ratio (AMFR) by age group in a large population (nationwide), and its ecological association (at county level) with some medical, geographical, or sociodemographic factors. METHODS: Registries of the largest medical institution in Mexico (∼37.5 million subjects assigned to a family physician) were analyzed and the AMFR calculated using asthma incidences. RESULTS: In boys, asthma incidence peaked at 0 to 4 years and progressively decreased, reaching a plateau in adulthood. In girls, asthma incidence showed a bimodal pattern, with maximal rates at 0 to 4 years old, and again at 50 to 54 years old. In the ecological analysis performed in more than 400 counties, the AMFR in adults (≥15 years old) inversely correlated with population density (r = -0.256) and altitude (r = -0.144), and directly correlated with acute respiratory tract infections (ARTI, r = 0.215), diabetes (r = 0.186), marginalization (r = 0.179), pneumonias (r = 0.166), and mean maximal temperature (r = 0.142), all with P < .01. In the multiple linear regression, only population density (P < .001) and ARTI (P = .006) remained statistically significant in the final model. CONCLUSION: Asthma incidence in males and females did not match the expected sexual hormones variations, and other factors such as population density and ARTI also influenced the AMFR. These findings challenge the traditional belief that sexual hormones are major determinants of the AMFR.

CETP-derived Peptide Seq-1, the Key Component of HB-ATV-8 Vaccine Prevents Stress Responses, and Promotes Downregulation of Pro-Fibrotic Genes in Hepatocytes and Stellate Cells.

BACKGROUND: The nasal vaccine HB-ATV-8 has emerged as a promising approach for NAFLD (non-alcoholic fatty liver disease) and atherosclerosis prevention. HB-ATV-8 contains peptide seq-1 derived from the carboxy-end of the Cholesteryl Ester Transfer Protein (CETP), shown to reduce liver fibrosis, inflammation, and atherosclerotic plaque formation in animal models. Beyond the fact that this vaccine induces B-cell lymphocytes to code for antibodies against the seq-1 sequence, inhibiting CETP's cholesterol transfer activity, we have hypothesized that beyond the modulation of CETP activity carried out by neutralizing antibodies, the observed molecular effects may also correspond to the direct action of peptide seq-1 on diverse cellular systems and molecular features involved in the development of liver fibrosis. METHODS: The HepG2 hepatoma-derived cell line was employed to establish an in vitro steatosis model. To obtain a conditioned cell medium to be used with hepatic stellate cell (HSC) cultures, HepG2 cells were exposed to fatty acids or fatty acids plus peptide seq-1, and the culture medium was collected. Gene regulation of COL1A1, ACTA2, TGF-ß, and the expression of proteins COL1A1, MMP-2, and TIMP-2 were studied. AIM: To establish an in vitro steatosis model employing HepG2 cells that mimics molecular processes observed in vivo during the onset of liver fibrosis. To evaluate the effect of peptide Seq-1 on lipid accumulation and pro-fibrotic responses. To study the effect of Seq-1-treated steatotic HepG2 cell supernatants on lipid accumulation, oxidative stress, and pro-fibrotic responses in HSC. RESULTS AND CONCLUSION: Peptide seq-1-treated HepG2 cells show a downregulation of COLIA1, ACTA2, and TGF-ß genes, and a decreased expression of proteins such as COL1A1, MMP-2, and TIMP-2, associated with the remodeling of extracellular matrix components. The same results are observed when HSCs are incubated with peptide Seq-1-treated steatotic HepG2 cell supernatants. The present study consolidates the nasal vaccine HB-ATV-8 as a new prospect in the treatment of NASH directly associated with the development of cardiovascular disease.

Trends (2007-2019) of major atopic diseases throughout the life span in a large Mexican population.

Background: Major atopic diseases such as atopic dermatitis (AD), allergic rhinitis (AR), and asthma share the same atopic background, but they often show differences in their epidemiological behavior. Objective: We aimed to report the profile of these atopic diseases in a large Mexican population, including their age-related incidences, male:female (M:F) ratios, recent time trends, and association with altitude. Methods: Registries from the largest, nationwide health institution in Mexico (more than 34 million insured subjects), were reviewed. New cases of AD, AR, and asthma diagnosed each year by family physicians from 2007 to 2019 were adjusted by the corresponding insured population to estimate incidence rates. Results: Incidences of the 3 atopic diseases were highest in the 0-4 years age-group and progressively decreased thereafter until adolescence. Asthma and AR, but not AD, were more frequent in males during childhood (M:F ratios of 1.5, 1.3, and 0.95, respectively), but predominated in females during adulthood (M:F ratios of 0.52, 0.68, and 0.73, respectively). Time trends showed an initial increasing trend of annual incidences, with a peak around 2009-2011, and a downward trend afterward. This decreasing trend was seen in all age-groups and was more evident for AD (∼50% drop) and asthma (∼40% drop) than for AR (∼20% drop). Geographical distribution suggested that incidences of asthma and AR, but not of AD, had an inverse association with altitude. Conclusion: Annual incidences of the 3 major atopic diseases have declined in recent years in almost all age groups, and their epidemiological profile during the life span showed contrasting differences according to age, sex, and ecological association with altitude, mainly regarding AD.

Arachidonate 5 lipoxygenase expression in papillary thyroid carcinoma promotes invasion via MMP-9 induction.

Arachidonate 5-lipoxygenase (ALOX5) expression and activity has been implicated in tumor pathogenesis, yet its role in papillary thyroid carcinoma (PTC) has not been characterized. ALOX5 protein and mRNA were upregulated in PTC compared to matched, normal thyroid tissue, and ALOX5 expression correlated with invasive tumor histopathology. Evidence suggests that PTC invasion is mediated through the induction of matrix metalloproteinases (MMPs) that can degrade and remodel the extracellular matrix (ECM). A correlation between MMP-9 and ALOX5 protein expression was established by immunohistochemical analysis of PTC and normal thyroid tissues using a tissue array. Transfection of ALOX5 into a PTC cell line (BCPAP) increased MMP-9 secretion and cell invasion across an ECM barrier. The ALOX5 product, 5(S)-hydroxyeicosatetraenoic acid also increased MMP-9 protein expression by BCPAP in a dose-dependent manner. Inhibitors of MMP-9 and ALOX5 reversed ALOX5-enhanced invasion. Here we describe a new role for ALOX5 as a mediator of invasion via MMP-9 induction; this ALOX5/MMP9 pathway represents a new avenue in the search for functional biomarkers and/or potential therapeutic targets for aggressive PTC.

Clinical usefulness of angiogenic factors in women with chronic kidney disease and suspected superimposed preeclampsia.

BACKGROUND: Preeclampsia is a condition often superimposed to CKD. OBJECTIVE: The purpose of this study was to evaluate the clinical characteristics and outcomes of pregnant women with chronic kidney disease (CKD) with suspected superimposed preeclampsia, stratified according to the degree of their angiogenic imbalance, as assessed by the soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio. METHODS: Using a cross-sectional design, we studied 171 pregnancies in patients with CKD and with suspected superimposed preeclampsia, admitted to a teaching hospital. Patients were divided into three groups based on their degree of angiogenic imbalance, evaluated by the sFlt-1/PlGF ratio: no angiogenic imbalance (sFlt-1/PlGF ratio≤ 38), mild angiogenic imbalance (sFlt-1/PlGF ratio> 38 to < 85), and severe angiogenic imbalance (sFlt-1/PlGF ratio≥ 85). Superimposed preeclampsia and preeclampsia-related adverse outcomes were defined according to The American College of Obstetricians and Gynecology criteria.  Measurements of sFlt-1 and PlGF were performed on single serum samples using the Elecsys sFlt-1 and PlGF assays (Roche Diagnostics). Serum soluble endoglin (sEng) levels were also determined (ELISA R&D Systems, Minneapolis, MN). Glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, whenever possible on pre-prengancy data. RESULTS: Patients with severe angiogenic imbalance had higher rates of confirmed superimposed preeclampsia and preeclampsia-related adverse maternal and perinatal outcomes (p < 0.001) when compared to patients with no or mild angiogenic imbalance. A significant trend towards higher serum sEng levels was observed as the degree of angiogenic imbalance increased. Interestingly, the rate of progression to superimposed preeclampsia increased progressively as the degree of angiogenic imbalance increased (no 11.8%, mild 60.0%, and severe 100%). CONCLUSION: In women with CKD and suspected superimposed preeclampsia, severe angiogenic imbalance was associated with confirmed superimposed preeclampsia or progression to superimposed preeclampsia. Patients with no angiogenic imbalance displayed lower rates of progression to superimposed preeclampsia, whereas outcomes were intermediate, supporting a systematic use of sFlt-1/PlGF ratio, and other biomarkers in the clinical management of CKD pregnacies.

[Early alert of COVID-19 outbreaks to plan the response in the IMSS]. / Alerta temprana de brotes COVID-19 para planear la respuesta en el IMSS.

The Instituto Mexicano del Seguro Social (IMSS) developed and implemented epidemic monitoring and modeling tools to support the organization and planning of an adequate and timely response to the COVID-19 health emergency. The aim of this article is to describe the methodology and results of the early outbreak detection tool called COVID-19 Alert. An early warning traffic light was developed that uses time series analysis and a Bayesian method of early detection of outbreaks from electronic records on COVID-19 for suspected cases, confirmed cases, disabilities, hospitalizations, and deaths. Through Alerta COVID-19, the beginning of the fifth wave of COVID-19 in the IMSS was detected in a timely manner, three weeks before the official declaration. The proposed method is aimed at generating early warnings before the start of a new wave of COVID-19, monitoring the serious phase of the epidemic, and supporting decision-making within the institution; unlike other tools that have an approach aimed at communicating risks to the community. We can conclude that the Alerta COVID-19 is an agile tool that incorporates robust methods for the early detection of outbreaks.

El Instituto Mexicano del Seguro Social (IMSS) desarrolló e implementó herramientas de monitoreo y modelación de la epidemia para apoyar la organización y planeación de la respuesta adecuada y oportuna a la emergencia sanitaria por COVID-19. El objetivo de este trabajo es describir la metodología y los resultados de la herramienta de detección temprana de brotes denominada Alerta COVID-19. Se desarrolló un semáforo de alertamiento temprano que utiliza análisis de series temporales, así como un método bayesiano de detección temprana de brotes a partir de los registros electrónicos sobre COVID-19 para casos sospechosos, confirmados, incapacidades, hospitalizaciones y defunciones. A través de la Alerta COVID-19 se detectó oportunamente, con tres semanas de anticipación a la declaratoria oficial, el inicio de la quinta ola de COVID-19 en el IMSS. El método propuesto está orientado a generar alertas tempranas ante el inicio de una nueva ola de COVID-19, monitorear la fase grave de la epidemia y apoyar la toma de decisiones al interior de la institución; a diferencia de otras herramientas que tienen un enfoque dirigido a la comunicación de riesgos a la comunidad. Podemos concluir que la Alerta COVID-19 es una herramienta ágil que incorpora métodos robustos para la detección temprana de brotes.

New insights into lipopolysaccharide inactivation mechanisms in sepsis.

The complex pathophysiology of sepsis makes it a syndrome with limited therapeutic options and a high mortality rate. Gram-negative bacteria containing lipopolysaccharides (LPS) in their outer membrane correspond to the most common cause of sepsis. Since the gut is considered an important source of LPS, intestinal damage has been considered a cause and a consequence of sepsis. Although important in the maintenance of the intestinal epithelial cell homeostasis, the microbiota has been considered a source of LPS. Recent studies have started to shed light on how sepsis is triggered by dysbiosis, and an increased inflammatory state of the intestinal epithelial cells, expanding the understanding of the gut-liver axis in sepsis. Here, we review the gut-liver interaction in Gram-negative sepsis, exploring the mechanisms of LPS inactivation, including the recently described contribution of an isoform of the cholesteryl-ester transfer protein (CETPI). Although several key questions remain to be answered when the pathophysiology of sepsis is reviewed, new contributions coming to light exploring the way LPS might be inactivated in vivo, suggest that new applications might soon reach the clinical setting.

Peptides as Therapeutic Molecules to Neutralize Gram-negative Bacterial Lipopolysaccharides in Sepsis and Septic Shock.

During the last years, infections have become a global health emergency, where the appearance of bacteria highly resistant to traditional antibiotics have set off an alarm worldwide. Moreover, the increased incidence and mortality resulting from its aggravated states, sepsis, and septic shock, have been observed with growing concern. In this context, knowing the need for a new concept for treatment, peptides such as antimicrobial peptides (AMP) and host defense peptides (HDP), have started to show interesting properties in the development of new antimicrobial agents and host response modulatory therapies. Nevertheless, since it is a well-known fact that a peptide-based drug development is a long process that consumes a significant number of resources, recent approaches that tend to mitigate these obstacles, have included the implementation of novel in silico strategies for the optimization of naturally occurring AMP and HDP. In this review, we analyze these strategies that seek to improve not only peptide design, but also production, by including the incorporation of computational biology techniques such as molecular dynamics.

Peptide VSAK maintains tissue glucose uptake and attenuates pro-inflammatory responses caused by LPS in an experimental model of the systemic inflammatory response syndrome: a PET study.

The present investigation using Positron Emission Tomography shows how peptide VSAK can reduce the detrimental effects produced by lipopolysaccharides in Dutch dwarf rabbits, used to develop the Systemic Inflammatory Response Syndrome (SIRS). Animals concomitantly treated with lipopolysaccharides (LPS) and peptide VSAK show important protection in the loss of radiolabeled-glucose uptake observed in diverse organs when animals are exclusively treated with LPS. Treatment with peptide VSAK prevented the onset of changes in serum levels of glucose and insulin associated with the establishment of SIRS and the insulin resistance-like syndrome. Treatment with peptide VSAK also allowed an important attenuation in the circulating levels of pro-inflammatory molecules in LPS-treated animals. As a whole, our data suggest that peptide VSAK might be considered as a candidate in the development of new therapeutic possibilities focused on mitigating the harmful effects produced by lipopolysaccharides during the course of SIRS.

Lipid Modulation in the Formation of ß-Sheet Structures. Implications for De Novo Design of Human Islet Amyloid Polypeptide and the Impact on ß-Cell Homeostasis.

Human islet amyloid polypeptide (hIAPP) corresponds to a 37-residue hormone present in insulin granules that maintains a high propensity to form ß-sheet structures during co-secretion with insulin. Previously, employing a biomimetic approach, we proposed a panel of optimized IAPP sequences with only one residue substitution that shows the capability to reduce amyloidogenesis. Taking into account that specific membrane lipids have been considered as a key factor in the induction of cytotoxicity, in this study, following the same design strategy, we characterize the effect of a series of lipids upon several polypeptide domains that show the highest aggregation propensity. The characterization of the C-native segment of hIAPP (residues F23-Y37), together with novel variants F23R and I26A allowed us to demonstrate an effect upon the formation of ß-sheet structures. Our results suggest that zwitterionic phospholipids promote adsorption of the C-native segments at the lipid-interface and ß-sheet formation with the exception of the F23R variant. Moreover, the presence of cholesterol did not modify this behavior, and the ß-sheet structural transitions were not registered when the N-terminal domain of hIAPP (K1-S20) was characterized. Considering that insulin granules are enriched in phosphatidylserine (PS), the property of lipid vesicles containing negatively charged lipids was also evaluated. We found that these types of lipids promote ß-sheet conformational transitions in both the C-native segment and the new variants. Furthermore, these PS/peptides arrangements are internalized in Langerhans islet ß-cells, localized in the endoplasmic reticulum, and trigger critical pathways such as unfolded protein response (UPR), affecting insulin secretion. Since this phenomenon was associated with the presence of cytotoxicity on Langerhans islet ß-cells, it can be concluded that the anionic lipid environment and degree of solvation are critical conditions for the stability of segments with the propensity to form ß-sheet structures, a situation that will eventually affect the structural characteristics and stability of IAPP within insulin granules, thus modifying the insulin secretion.

Gene expression profiling identifies potential molecular markers of papillary thyroid carcinoma.

BACKGROUND: Thyroid cancer is the most common endocrine malignancy worldwide, with the predominant form papillary thyroid carcinoma (PTC) representing approximately 80% of cases. OBJECTIVE: This study was addressed to identify potential genes and pathways involved in the pathogenesis of PTC and potential novel biomarkers for this disease. METHODS: Gene expression profiling was carried out by DNA microarray technology. Validation of microarray data by qRT-PCR, western blot, and enzyme linked immunosorbent assay was also performed in a selected set of genes and gene products, with the potential to be used as diagnostic or prognostic biomarkers, such as those associated with cell adhesion, extracellular matrix (ECM) remodeling and immune/inflammatory response. RESULTS: In this study we found that upregulation of extracellular activities, such as proteoglycans, ECM-receptor interaction, and cell adhesion molecules, were the most prominent feature of PTC. Significantly over-expressed genes included SDC1 (syndecan 1), SDC4 (syndecan 4), KLK7 (kallikrein-related peptidase 7), KLK10 (kallikrein-related peptidase 10), SLPI (secretory leukocyte peptidase inhibitor), GDF15 (growth/differentiation factor-15), ALOX5 (arachidonate 5-lipoxygenase), SFRP2 (secreted Frizzled-related protein 2), among others. Further, elevated KLK10 levels were detected in patients with PTC. Many of these genes belong to KEGG pathway "Proteoglycans in cancer". CONCLUSIONS: Using DNA microarray analysis allowed the identification of genes and pathways with known important roles in malignant transformation, and also the discovery of novel genes that may be potential biomarkers for PTC.

Mortality from type 2 diabetes and implementation of the PREVENIMSS program: a time series study in Mexico, 1998-2015. / Mortalidad por diabetes tipo 2 y la implementación del programa PREVENIMSS: un estudio de series de tiempo en México, 1998-2015.

Type 2 diabetes is the leading cause of morbidity and mortality in the world. In Mexico it is the first cause of mortality, disability, and potential years of life lost due to premature death. The Mexican Institute of Social Security (IMSS) implemented the PREVENIMSS strategy. The aim of the current study was to estimate the program's effect on the mortality trend from type 2 diabetes, based on an interrupted time series analysis. At the beginning of the target period, the diabetes mortality rate was higher in IMSS beneficiaries than in the control population. After the program's implementation, there was a slight reduction in the mortality trend, while the control group showed an upward trend. Differences in the trends between the two groups suggest that they are not the exclusive result of institutional interventions. Living and work conditions could explain these differences.

La diabetes tipo 2 es la principal causa de mortalidad y morbilidad en el mundo. En México es la primera causa de mortalidad, discapacidad, años perdidos por muerte prematura. El Instituto Mexicano del Seguro Social (IMSS) implementó la estrategia PREVENIMSS. El objetivo del presente estudio es determinar el efecto de dicho programa en la tendencia de la mortalidad por diabetes tipo 2, realizando un análisis de series de tiempo interrumpidas. Al inicio del periodo de tiempo analizado, la tasa de mortalidad de diabetes en los derechohabientes era mayor, en comparación con la población control. Posterior a la implementación del programa, se presentó una discreta reducción en la tendencia de la mortalidad, mientras que en el grupo control la tendencia fue ascendente. Las diferencias encontradas en las tendencias entre las poblaciones comparadas sugieren que no son resultado exclusivo de las intervenciones institucionales. Las condiciones de vida y de trabajo podrían explicar dichas diferencias.

O diabetes tipo 2 é a primeira causa de morbi-mortalidade no mundo. No México, é a primeira causa de mortalidade, incapacidade e anos de vida perdidos. O Instituto Mexicano de Seguridade Social (IMSS) implementou a estratégia conhecida como PREVENIMSS. O estudo atual teve como objetivo estimar o efeito do programa sobre a tendência na mortalidade por diabetes tipo 2, com base em uma análise de série temporal ininterrupta. No início do período de estudo, a taxa de mortalidade por diabetes era mais alta entre segurados do IMSS do que na população controle. Depois da implementação do programa, houve uma pequena redução na mortalidade, enquanto o grupo controle mostrava uma tendência crescente. Diferenças nas tendências entre os dois grupos sugerem que não resultam exclusivamente de intervenções institucionais. As condições de vida e de trabalho podem ajudar a explicar essas diferenças.

Altitude above 1500 m is a major determinant of asthma incidence. An ecological study.

BACKGROUND: Previous studies suggest an inverse correlation between asthma and altitude. In the present work, we performed an in-depth analysis of asthma incidence in the 758 Mexican counties covered by the largest medical institution in the country (∼37.5 million insured subjects), and evaluated its relationships with altitude and other factors. METHODS: Asthma incidence in each county was calculated from new cases diagnosed by family physicians. Other variables in the same counties, including selected diseases, geographical variables, and socioeconomic factors, were also obtained and their association with asthma was evaluated through bivariate and multivariate analyses. RESULTS: Median asthma incidence was 296.2 × 100,000 insured subjects, but tended to be higher in those counties located on or near the coast. When asthma incidence was plotted against altitude, a two-stage pattern was evident: asthma rates were relatively stable in counties located below an altitude of ∼1500 m, while these rates progressively decreased as altitude increased beyond this level (rS = -0.51, p < .001). Multivariate analysis showed that, once each variable was adjusted by the potential influence of the others, asthma incidence was inversely correlated with altitude (standardized ß coefficient, -0.577), helminthiasis (-0.173), pulmonary tuberculosis (-0.130), and latitude (-0.126), and was positively correlated with acute respiratory tract infection (0.382), pneumonia (0.289), type 2 diabetes (0.138), population (0.108), and pharyngotonsillitis (0.088), all with a p ≤ .001. CONCLUSION: Our study showed that altitude higher than ∼1500 m comprises a major factor in determining asthma incidence, with the risk of new-onset asthma decreasing as altitude increases. Other less influential conditions were also identified.

[Cytotoxicity of the herbicide glyphosate in human peripheral blood mononuclear cells]. / Citotoxicidad del glifosato en células mononucleares de sangre periférica humana.

INTRODUCTION: Glyphosate is a broad-spectrum, non-selective herbicide and commonly used to eliminate weeds in agricultural and forest settings. Studies evaluating glyphosate toxicity in animals and environment show that commercial formulations of glyphosate are more toxic than the active component itself. OBJECTIVES: Technical grade glyphosate was compared with the commercial formulation Roundup in their respective toxicities on human peripheral blood mononuclear cells. MATERIALS AND METHODS: Human peripheral blood mononuclear cells were exposed to different concentrations of glyphosate, either technical grade or in the form of Roundup for 24 h, 48 h, 72 h, and 96 h. Cytotoxicity was assayed by trypan blue dye exclusion method and reduction of (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2Htetrazolium-5-carboxyanilide inner salt)XTT reagent. RESULTS: Both technical grade glyphosate and Roundup formulation were toxic to human peripheral blood mononuclear cells. Cytotoxicity of Roundup was higher than cytotoxicity of glyphosate, since the LC50 (50% lethal concentration) determined by the trypan blue exclusion method at 24 h was the equivalent of 56.4 microg/ml of glyphosate in the form of Roundup and 1,640 microg/ml (1.64 mg/ml) for technical grade glyphosate. CONCLUSIONS: This in vitro study confirmed the toxic effects on human cells by glyphosate and its commercial preparations. Commercial formulations were more cytotoxic than the active component alone, supporting the concept that additives in commercial formulations play a role in the toxicity attributed to glyphosate-based herbicides.

Prevalence of Brucella abortus antibodies in equines of a tropical region of Mexico.

A cross-sectional study was conducted to determinate the seroprevalence rate of equine brucellosis in the state of Tamaulipas, Mexico. Serum samples from 420 equines were analyzed with the Rose Bengal test at cell concentrations of 3% (RBT-3%) and 8% (RBT-8%), and positive results were confirmed with the Rivanol test (RT). Risk factors were determined with the prevalence ratio (PR) and the use of variables generated from a questionnaire administered to the animals' owners. Serum from 1 stallion had positive results with both the RBT-8% and the RT, for a seroprevalence rate of 0.238%. Drinking of water from a pond that was also used by cattle and dogs was the only associated risk factor for this animal (PR = 0.25). However, the results were considered false-positive, because the results for other horses in the same environmental conditions were negative. Although brucellosis is considered endemic in ruminants in the study area, the results obtained suggest that equines are not a reservoir of brucellosis and do not play an important role in the epidemiologic patterns of this disease in northeastern Mexico.