HMGB1 decreases CCR-2 expression and migration of M2 macrophages under hypoxia

OBJECTIVE

The hypoxic milieu at tumor microenvironment is able to drive the behavior of infiltrating tumor cells. Considering that hypoxia-mediated HMGB1 release is known to promote tumor growth, as well to enhance the pro-tumoral profile of M2 macrophages by a RAGE-dependent mechanism, it is tempting to evaluate the potential contribution of HMGB1 under hypoxia to restrain M2 macrophages mobility.

METHODS

CCR-2 expression was evaluated in M2 polarized macrophages by western blotting and immunocytochemistry. The secreted levels of CCL-2 and the migration capability were evaluated using an ELISA and a chemotaxis assay, respectively.

RESULTS

HMGB1, under hypoxic conditions, markedly reduce both the production of CCL-2 and the expression of its receptor CCR-2; and reduced the migration capacity of M2 macrophages.

CONCLUSIONS

These results provided new insights into the mechanisms that regulate M2 macrophages mobility at the tumor microenvironment.

Detection of Intraspinal Spirocerca lupi in Canine Cerebrospinal Fluid by Polymerase Chain Reaction

Aberrant migration of Spirocerca lupi into the spinal cord is an important cause of severe progressive neurological dysfunction in dogs. Although early diagnosis is essential to prevent deterioration, ante-mortem diagnosis of this condition remains challenging. The aim of this study was to evaluate the detection of the 18S ribosomal DNA (rDNA) S. lupi gene in the cerebrospinal fluid (CSF) of presumptively-affected dogs using polymerase chain reaction (PCR). Dogs with a non-compressive spinal cord lesion, pleocytosis with presence of eosinophils in the CSF and a characteristic clinical presentation were included. CSF samples from eight dogs were available for the study, of which seven were definitively diagnosed with intraspinal spirocercosis by PCR of either the CSF samples (6/7) or tissue samples obtained at necropsy examination (3/7), or both (2/7). Of these seven positive cases, only one dog had a negative CSF PCR, indicating a sensitivity of 86% for detecting nematode DNA in the CSF of infected dogs using this PCR protocol. The nematode DNA sequences obtained from the CSF of six dogs and the spinal cord tissue of three dogs were 98-100% identical to the publicly available sequences of S. lupi, confirming the diagnosis. These findings indicate that PCR targeting the 18S rDNA of S. lupi in CSF is useful for the ante-mortem diagnosis of canine intraspinal spirocercosis.

Meta-analysis of routine calcium/vitamin D3 supplementation versus serum calcium level-based strategy to prevent postoperative hypocalcaemia after thyroidectomy

BACKGROUND

The aim was to assess the effectiveness of routine administration of calcium +/- vitamin D3 compared with a serum calcium level-based strategy to prevent symptomatic hypocalcaemia after thyroidectomy.

METHODS

RCTs comparing routine supplementation of calcium +/- vitamin D3 with treatment based on serum calcium levels measured after total thyroidectomy, published between 1980 and 2017, were identified in MEDLINE, Embase, LILACS and Google Scholar databases. Risk of bias was evaluated using the Cochrane Collaboration tool. Risk differences were calculated by random-effects meta-analysis. Meta-regression and cumulative meta-analysis were used to explore the best therapeutic approach.

RESULTS

Fifteen studies with 3037 patients were included, and seven treatment comparisons were made. Routine supplementation with calcium + vitamin D3 offered a lower risk of symptomatic (risk difference (RD) -0·25, 95 per cent c.i. -0·32 to -0·18) and biochemical (RD -0·24, -0·31 to -0·17) hypocalcaemia than treatment based on measurement of calcium levels. The number needed to treat was 4 (95 per cent c.i. 3 to 6) for symptomatic hypocalcaemia. No publication bias was found; although heterogeneity was high for some comparisons, sensitivity analysis did not change the main results.

CONCLUSION

Routine postoperative administration of calcium + vitamin D3 is effective in decreasing the rate of symptomatic and biochemical hypocalcaemia.

Pathogenic potential of Helicobacter pylori strains can explain differences in H. pylori associated diseases rates from Chile and Cuba

Background: The prevalence of Helicobacter pylori-related diseases varies geographically and it is partially determined by the virulence of the circulating strains. Cuba and Chile exhibit different gastric cancer rates, on despite of very similar H. pylori infection rates. We determined if differences in the pathogenic potential of H. pylori isolates from Chile and Cuba could explain the disease outcome in each population. Methods: H. pylori isolates from 78 Chilean and 71 Cuban patients were analyzed using PCR for the presence of cagA, babA2, vacA alleles and the pattern of EPIYA motifs. Results: cagA was detected in 94.9 % of Chilean and 64.7 % of Cuban isolates (P < 0.001) and was significantly associated with duodenal ulcer (DU) in Cuba (P < 0.01) but not in Chile. The presence of cagA with multiple EPIYA-C motifs was 18.2 % higher in Chile than in Cuba (P < 0.05). Also, an association was observed between GU (P ≤ 0.05) and premalignant lesions (P < 0.001) with the multiple EPIYA-C motif status of the strains in Chile, but not in Cuba. The prevalence of vacA s2m2 genotype was predominant in Chile (66.7 %), while in Cuba was prevalent the s1m1 genotype (56.8 %); and the last one was significantly associated with the presence of DU in Cuban patients. Conclusions: The cagA status and the EPIYA pattern found in Chilean and Cuban H. pylori clinical isolates partially explain the differences in disease prevalence between both countries. The high proportion of vacA s2m2 genotype in Chile was an unexpected result, needing further studies. Bangladesh Journal of Medical Science Vol.18(3) 2019 p.577-585

Treatment, outcomes and costs of asthma exacerbations in Chilean children: a prospective multicenter observational study

OBJECTIVE

To describe potential regional variations in therapies for severe asthma exacerbations in Chilean children and estimate the associated health expenditures.

METHODS

Observational prospective cohort study in 14 hospitals over a one-year period. Children five years of age or older were eligible for inclusion. Days with oxygen supply and pharmacological treatments received were recorded from the clinical chart. A basic asthma hospitalization basket was defined in order to estimate the average hospitalization cost for a single patient. Six months after discharge, new visits to the Emergency Room (ER), use of systemic corticosteroids and adherence to the controller treatment were evaluated.

RESULTS

396 patients were enrolled. Patients from the public health system and from the north zone received significantly more days of oxygen, systemic corticosteroids and antibiotics. Great heterogeneity in antibiotic use among the participating hospitals was found, from 0 to 92.3% (ICC 0.34, 95% CI 0.16-0.52). The use of aminophylline, magnesium sulfate and ketamine varied from 0 to 36.4% between the different Pediatric Intensive Care Units (ICC 0.353, 95% CI 0.010-0.608). The average cost per inpatient was of $1910 USD. 290 patients (73.2%) completed the follow-up six months after discharge. 76 patients (26.2%) were not receiving any controller treatment and nearly a fourth had new ER visits and use of systemic corticosteroids due to new asthma exacerbations.

CONCLUSIONS

Considerable practice variation in asthma exacerbations treatment was found among the participating hospitals, highlighting the poor outcome of many patients after hospital discharge, with an important health cost.

Rates, predictors and mortality of community-onset bloodstream infections due to Pseudomonas aeruginosa: systematic review and meta-analysis

BACKGROUND

Pseudomonas aeruginosa is mostly a nosocomial pathogen affecting predisposed patients. However, community-onset bloodstream infections (CO-BSI) caused by this organism are not exceptional.

OBJECTIVES

To assess the predisposing factors for CO-BSI due to P. aeruginosa (CO-BSI-PA) and the impact in mortality of inappropriate empirical antimicrobial therapy.

DATA SOURCE

A systematic literature search was performed in the Medline, Embase, Cochrane Library, Scopus and Web of Science databases. Study eligibility criteria and participants: Articles published between 1 January 2002 and 31 January 2018 reporting at least of 20 adult patients with CO-BSI due to P. aeruginosa were considered.

INTERVENTION

Empiric antimicrobial therapy for CO-BSI-PA.

METHODS

A systematic review and a meta-analysis were conducted for risk factors and to evaluate if inappropriate empiric antimicrobial therapy increased mortality in CO-BSI-PA using a Mantel-Haenszel effects model.

RESULTS

Twelve studies assessing data of 1120 patients were included in the systematic review. Solid tumour (33.1%), haematologic malignancy (26.4%), neutropenia (31.7%) and previous antibiotic use (44.8%) were the most prevalent predisposing factors. Septic shock was present in 42.3% of cases, and 30-day crude mortality was 33.8%. Mortality in meta-analysis (four studies) was associated with septic shock at presentation (odds ratio, 22.31; 95% confidence interval, 3.52-141.35; p 0.001) and with inappropriate empiric antibiotic therapy (odds ratio, 1.83; 95% confidence interval, 1.12-2.98l p 0.02).

CONCLUSIONS

CO-BSI-PA mostly occurred in patients with predisposing factors and had a 30-day mortality comparable to hospital-acquired cases. Inappropriate empirical antibiotic therapy was associated with increased mortality. Appropriate identification of patients at risk for CO-BSI-PA is needed for empirical treatment decisions.

Inhibition of RAGE Axis Signaling: A Pharmacological Challenge

The Receptor for Advanced Glycation End Products (RAGE) is an important cell surface receptor, which belongs to the IgG super family and is now considered as a pattern recognition receptor. Because of its relevance in many human clinical settings, it is now pursued as a very attractive therapeutic target. However, particular features of this receptor such as a wide repertoire of ligands with different binding domains, the existence of many RAGE variants as well as the presence of cytoplasmatic adaptors leading a diverse signaling, are important limitations in the search for successful pharmacological approaches to inhibit RAGE signaling. Therefore, the present review aimed to display the most promising approaches to inhibit RAGE signaling, and provide an up to date review of progress in this area.

Skewed Signaling through the Receptor for Advanced Glycation End-Products Alters the Proinflammatory Profile of Tumor-Associated Macrophages

Tumors are complex tissues composed of variable amounts of both non-cellular components (matrix proteins) and a multitude of stromal cell types, which are under an active cross-talk with tumor cells. Tumor-associated macrophages (TAMs) are the major leukocyte population among the tumor-infiltrating immune cells. Once they are infiltrated into tumor stroma they undergo a polarized activation, where the M1 and M2 phenotypes represent the two extreme of the polarization heterogeneity spectrum. It is known that TAMs acquire a specific phenotype (M2), oriented toward tumor growth, angiogenesis and immune-suppression. A growing body of evidences supports the presence of tuning mechanisms in order to skew or restraint the inflammatory response of TAMs and thus forces them to function as active tumor-promoting immune cells. The receptor of advanced glycation end-products (RAGE) is a member of the immunoglobulin protein family of cell surface molecules, being activated by several danger signals and thus signaling to promote the production of many pro-inflammatory molecules. Interestingly, this receptor is paradoxically expressed in both M1 and M2 macrophages phenotypes. This review addresses how RAGE signaling has been drifted away in M2 macrophages, and thus taking advantage of the abundance of RAGE ligands at tumor microenvironment, particularly HMGB1, to reinforce the supportive M2 macrophages strategy to support tumor growth.

Hospitalizations for asthma exacerbation in Chilean children: A multicenter observational study

BACKGROUND

Asthma hospitalization rates in Chilean children have increased in the last 14 years, but little is known about the factors associated with this.

OBJECTIVE

Describe clinical characteristics of children hospitalized for asthma exacerbation.

METHODS

Observational prospective cohort study in 14 hospitals. Over a one-year period, children five years of age or older hospitalized with asthma exacerbation were eligible for inclusion. Parents completed an online questionnaire with questions on demographic information, about asthma, indoor environmental contaminant exposure, comorbidities and beliefs about disease and treatment. Disease control was assessed by the Asthma Control Test. Inhalation technique was observed using a checklist.

RESULTS

396 patients were enrolled. 168 children did not have an established diagnosis of asthma. Only 188 used at least one controller treatment at the time of hospitalization. 208 parents said they believed their child had asthma only when they had an exacerbation and 97 correctly identified inhaled corticosteroids as anti-inflammatory treatment. 342 patients used the wrong spacer and 73 correctly performed all steps of the checklist.

CONCLUSIONS

Almost half of the patients were not diagnosed with asthma at the time of hospitalization despite having a medical history suggestive of the disease. In the remaining patients with an established diagnosis of asthma potentially modifiable factors like bad adherence to treatment and poor inhalation technique were found. Implementing a nationwide asthma program including continued medical education for the correct diagnosis and follow up of these patients and asthma education for patients and caregivers is needed to reduce asthma hospitalization rates in Chilean children.

Extracellular matrix glycation and receptor for advanced glycation end-products activation: a missing piece in the puzzle of the association between diabetes and cancer

A growing body of epidemiologic evidence suggests that people with diabetes are at a significantly higher risk of many forms of cancer. However, the molecular mechanisms underlying this association are not fully understood. Cancer cells are surrounded by a complex milieu, also known as tumor microenvironment, which contributes to the development and metastasis of tumors. Of note, one of the major components of this niche is the extracellular matrix (ECM), which becomes highly disorganized during neoplastic progression, thereby stimulating cancer cell transformation, growth and spread. One of the consequences of chronic hyperglycemia, the most frequently observed sign of diabetes and the etiological source of diabetes complications, is the irreversible glycation and oxidation of proteins and lipids leading to the formation of the advanced glycation end-products (AGEs). These compounds may covalently crosslink and biochemically modify structure and functions of many proteins, and AGEs accumulation is particularly high in long-living proteins with low biological turnover, features that are shared by most, if not all, ECM proteins. AGEs-modified proteins are recognized by AGE-binding proteins, and thus glycated ECM components have the potential to trigger Receptor for advanced glycation end-products-dependent mechanisms. The biological consequence of receptor for advanced glycation end-products activation mechanisms seems to be connected, in different ways, to drive some hallmarks of cancer onset and tumor growth. The present review intends to highlight the potential impact of ECM glycation on tumor progression by triggering receptor for advanced glycation end-products-mediated mechanisms.

Dermal Collagen Stabilization by Polyphenols and Spray Drying as an Encapsulation Strategy

Collagen, the most abundant component in mammalian tissues, has a crucial impact at skin level. Both promotion and maintenance of cross-linked collagen at the skin are critical to sustain the functionality and appearance of that tissue. Lysyl oxidases, also known as LOX enzymes, are the major collagen cross-linking enzymes that play a pivotal role in homeostasis. This minireview summarizes evidence that describes an amino oxidase-like activity, which could be attributed to polyphenols, or where polyphenols could be required. We also discuss some available collagen formulations and the scientific evidence that describes the impact on dermal extracellular matrix. In addition, information about encapsulation strategies to carry polyphenols, and some examples are also provided.

Pathogenicity and Virulence of Soilborne Oomycetes on Phaseolus vulgaris

Dry bean (Phaseolus vulgaris L.) is a globally important leguminous food crop. Yields can be reduced by high incidence of soilborne oomycetes that cause seedling disease. Breeders have attempted to develop Pythium root rot-resistant bean varieties; however, relationships between dry bean and most soilborne oomycete species remain uncharacterized. Oomycete species (n = 28), including Pythium spp. and Phytopythium spp., were tested in a growth chamber seedling assay at 20°C and an in vitro seed assay at 20°C and 26°C to evaluate their pathogenicity and virulence on 'Red Hawk' dark red kidney bean and 'Zorro' black bean. Root size or disease severity was significantly impacted by 14 oomycete species, though results varied by bean variety, temperature, and assay. Of these 14 pathogenic oomycete species, 11 species exhibited significant differences in DSI due to temperature on at least one bean variety. Pythium aphanidermatum, P. myriotylum, P. ultimum, P. ultimum var. sporangiiferium, and P. ultimum var. ultimum were the most virulent species in both assays, causing seed rot and pre-emergence damping-off of dry bean. Oomycete species were clustered into three groups based on symptom development: seed rot pathogens, root rot pathogens, or nonpathogens. Intraspecific variability in virulence was observed for eight of the 14 pathogenic oomycete species. Improved understanding of Pythium and Phytopythium interactions with dry bean may enable breeders and pathologists to more effectively evaluate strategies for oomycete seedling disease management.

Nuclear Force Imprints Revealed on the Elastic Scattering of Protons with ^{10}C

How does nature hold together protons and neutrons to form the wide variety of complex nuclei in the Universe? Describing many-nucleon systems from the fundamental theory of quantum chromodynamics has been the greatest challenge in answering this question. The chiral effective field theory description of the nuclear force now makes this possible but requires certain parameters that are not uniquely determined. Defining the nuclear force needs identification of observables sensitive to the different parametrizations. From a measurement of proton elastic scattering on ^{10}C at TRIUMF and ab initio nuclear reaction calculations, we show that the shape and magnitude of the measured differential cross section is strongly sensitive to the nuclear force prescription.

M2 macrophages do not fly into a "RAGE"

Tumor-associated macrophages (TAMs) are key elements in orchestrating host responses inside tumor stroma. This population may undergo a polarized activation process, thus rendering a heterogeneous spectrum of phenotypes, where the classically activated type 1 macrophages (M1) and the alternative activated type 2 macrophages (M2) represent two extreme phenotypes. In this commentary, based on very recent research findings, we intend to highlight how complex could be the crosstalk among all components of tumor stroma, where the coexistence of non-natural partners may even skew the canonical responses that we can expect.