SARS-CoV-2 seroprevalence in workers from a Colombian University Hospital.

BACKGROUND: Antibody (Ab) tests for SARS-CoV-2 virus allows for the estimation of incidence, level of exposure and duration of immunity acquired by a previous infection. In health workers, the hospital setting might convey a greater risk of infection. AIMS: To describe the frequency of immunoglobulin G (IgG) Abs (IgG-Abs) to the SARS-CoV-2 virus among workers at a third-level university hospital in Colombia. METHODS: In this cross-sectional study, we included medical and non-medical personnel with at least one real-time polymerase chain reaction (RT-PCR)/antigen test between March 2020 and March 2021. In April 2021, an IgG-Ab test against SARS-CoV-2 was conducted for all participants and replicated 2 weeks later in a random sample (10%). The frequency of IgG-Abs is presented based on status (positive/negative) and time elapsed since RT-PCR/antigen test (<3 months, 3-6 months, >6 months). RESULTS: We included 1021 workers (80% women, median age 34 years (interquartile range 28-42), 73% medical personnel, 23% with previous positive RT-PCR/antigen). The overall seroprevalence was 35% (95% CI 31.6-37.4, 35% in medical and 33% in non-medical personnel). For those with a previous positive RT-PCR/antigen test, the seroprevalence was 90% (<3 months), 82% (3-6 months) and 48% (>6 months). In participants with a previous negative RT-PCR/antigen test, the seroprevalence was 17% (<3 months), 21% (3-6 months) and 29% (>6 months). CONCLUSIONS: High IgG-Ab positivity was found in hospital personnel, regardless of work activities. The prevalence of detectable Abs differed by previous RT-PCR/antigen status and time elapsed since the diagnostic test.

Severity and duration of allergic conjunctivitis: are they associated with severity and duration of allergic rhinitis and asthma?

Summary: Objective. The association of allergic conjunctivitis (AC) with rhinitis and/or asthma is poorly understood. The objective of this study was to apply the Consensus Document for Allergic Conjunctivitis (DECA) criteria for the classification of AC to a population of patients with AC to assess the association between the severity and duration of AC and rhinitis and/or asthma. Methods. Patients with ocular symptoms of AC who participated in the 'Alergológica 2015' study were included. The demographics, classification according to the DECA criteria, etiology, and comorbidities were evaluated by age groups (less or equal than 14 and greater than 14 years). Results. A total of 2,914 patients (age range, 1-90 years) were included in the "Alergológica 2015" study. Of these, 965 patients (33.1%) were diagnosed with AC (77.5% > 14 years). AC was classified as severe, moderate, or mild in 1.8%, 46.4%, and 51.8%, respectively; and as intermittent or persistent in 51.6% and 48.4% of the patients. AC alone occurred in 4% of patients. AC was mainly associated with rhinitis (88.4%), asthma (38.2%), food allergy (8.3%) and atopic dermatitis (3.5%). In allergic respiratory disease rhinitis preceded AC and asthma developed later. The severity and duration of AC was significantly associated with severity and duration of rhinitis (p less than 0.001 for both age groups) and asthma (p less than 0.001 only in adults). Conclusions. The application of the new DECA classification for AC reveals a direct relationship between AC, rhinitis and asthma respect to severity and duration. These relationships suggest that AC should be considered an integral part of the "one airway, one disease" hypothesis.

[Analysis of mammograms performed in a public imaging center in Santiago, Metropolitan Region Chile 2008-2018]. / Estudios mamográficos en un centro metropolitano de referencia en imágenes mamarias: Chile 2008-2018 ¿Vamos por el camino correcto?

BACKGROUND: Mammograms are one of the most effective preventive means for the early detection of breast cancer. OBJECTIVE: To describe the features of patients and results of mammograms performed at a public breast imaging service of the Santiago Metropolitan Area. MATERIAL AND METHODS: We reviewed the reports of mammograms performed on 174,017 women and 18 men, between 2008 and 2018 in an Imaging Center. The BI-RADS classification was used in the reports. RESULTS: Forty-six percent of mammograms (75,781) were reported as BI-RADS 2. The high proportion of BI-RADS 4 reports (674 reports) was seen in patients aged 40 to 49 years, corresponding to 30% of reports in this age range. Among patients aged 50 to 59 years, there were 779 BI-RADS 4 reports (35%). BI-RADS 5 reports were more common among patients aged 50 to 59 years (50 reports, 30%) and among patients aged 70 years or older (83 reports, 28%). CONCLUSIONS: The presence of a significant number of women between 40 and 49 years of age with a BI-RADS 4 mammography result stands out; being an opportunity to develop new clinical research and public health strategies within the framework of the Universal Health Care policy for breast cancer in Chile.

EGFR mutation subtypes and response to immune checkpoint blockade treatment in non-small-cell lung cancer.

BACKGROUND: Although EGFR mutant tumors exhibit low response rates to immune checkpoint blockade overall, some EGFR mutant tumors do respond to these therapies; however, there is a lack of understanding of the characteristics of EGFR mutant lung tumors responsive to immune checkpoint blockade. PATIENTS AND METHODS: We retrospectively analyzed de-identified clinical and molecular data on 171 cases of EGFR mutant lung tumors treated with immune checkpoint inhibitors from the Yale Cancer Center, Memorial Sloan Kettering Cancer Center, University of California Los Angeles, and Dana Farber Cancer Institute. A separate cohort of 383 EGFR mutant lung cancer cases with sequencing data available from the Yale Cancer Center, Memorial Sloan Kettering Cancer Center, and The Cancer Genome Atlas was compiled to assess the relationship between tumor mutation burden and specific EGFR alterations. RESULTS: Compared with 212 EGFR wild-type lung cancers, outcomes with programmed cell death 1 or programmed death-ligand 1 (PD-(L)1) blockade were worse in patients with lung tumors harboring alterations in exon 19 of EGFR (EGFRΔ19) but similar for EGFRL858R lung tumors. EGFRT790M status and PD-L1 expression did not impact response or survival outcomes to immune checkpoint blockade. PD-L1 expression was similar across EGFR alleles. Lung tumors with EGFRΔ19 alterations harbored a lower tumor mutation burden compared with EGFRL858R lung tumors despite similar smoking history. CONCLUSIONS: EGFR mutant tumors have generally low response to immune checkpoint inhibitors, but outcomes vary by allele. Understanding the heterogeneity of EGFR mutant tumors may be informative for establishing the benefits and uses of PD-(L)1 therapies for patients with this disease.

Strong and frequent T-cell responses to the minor allergen Phl p 12 in Spanish patients IgE-sensitized to Profilins.

BACKGROUND: Profilins are dominant pan-allergens known to cause cross-sensitization, leading to clinical symptoms such as pollen-food syndrome. This study aimed to determine the T-cell response to Phl p 12 in profilin-sensitized patients, by measuring the prevalence, strength and cross-reactivity to clinically relevant profilins. METHODS: The release of Phl p allergens from pollen was determined by mass spectrometry and immunochemistry. T-cell responses, epitope mapping and cross-reactivity to profilins (Phl p 12, Ole e 2, Bet v 2 and Mal d 4) were measured in vitro using PBMCs from 26 Spanish grass-allergic donors IgE-sensitized to profilin. Cross-reactivity was addressed in vivo using 2 different mouse strains (BALB/c and C3H). RESULTS: Phl p 12 and Phl p 1 are released from pollen simultaneously and in similar amounts. Both T-cell response frequency (17/26 donors) and strength were comparable between Phl p 12 and Phl p 1. T-cell cross-reactivity to other profilins correlated with overall sequence homology, and 2 immunodominant epitope regions of Phl p 12 were identified. Data from mice immunized with Phl p 12 showed that cross-reactivity to Bet v 2 was mediated by conserved epitopes and further influenced by additional genetic factors, likely to be MHC II. CONCLUSION: The strength, prevalence and cross-reactivity of T-cell responses towards Phl p 12 are comparable to the major allergen Phl p 1, which supports the hypothesis that T cells to Phl p 12 can play an important role in development of allergic symptoms, such as those associated with pollen-food syndrome.

Position paper on nasal obstruction: evaluation and treatment.

Nasal obstruction (NO) is defined as the subjective perception of discomfort or difficulty in the passage of air through the nostrils. It is a common reason for consultation in primary and specialized care and may affect up to 30%-40% of the population. It affects quality of life (especially sleep) and lowers work efficiency. The aim of this document is to agree on how to treat NO, establish a methodology for evaluating and diagnosing it, and define an individualized approach to its treatment. NO can be unilateral or bilateral, intermittent or persistent and may be caused by local or systemic factors, which may be anatomical, inflammatory, neurological, hormonal, functional, environmental, or pharmacological in origin. Directed study of the medical history and physical examination are key for diagnosing the specific cause. NO may be evaluated using subjective assessment tools (visual analog scale, symptom score, standardized questionnaires) or by objective estimation (active anterior rhinomanometry, acoustic rhinometry, peak nasal inspiratory flow). Although there is little correlation between the results, they may be considered complementary and not exclusive. Assessing the impact on quality of life through questionnaires standardized according to the underlying disease is also advisable. NO is treated according to its cause. Treatment is fundamentally pharmacological (topical and/or systemic) when the etiology is inflammatory or functional. Surgery may be necessary when medical treatment fails to complement or improve medical treatment or when other therapeutic approaches are not possible. Combinations of surgical techniques and medical treatment may be necessary.

Relationship between respiratory and food allergy and evaluation of preventive measures.

Food allergy and respiratory allergy are two frequently associated diseases and with an increasing prevalence. Several reports show the presence of respiratory symptoms in patients with food allergy, while certain foods may be related to the development or exacerbation of allergic rhinitis and asthma. The present update focuses on this relationship, revealing a pathogenic and clinical association between food and respiratory allergy. This association is even more intense when the food hypersensitivity is persistent or starts in the early years of life. Food allergy usually precedes respiratory allergy and may be a risk factor for allergic rhinitis and asthma, becoming a relevant clinical marker for severe atopic asthma. Furthermore, the presence of co-existing asthma may enhance life-threatening symptoms occurring during a food allergic reaction. Recommendations for dietary restrictions during pregnancy and breastfeeding to prevent the development of respiratory allergy are controversial and not supported by consistent scientific data. Current recommendations from medical societies propose exclusive breastfeeding during the first four months of life, with the introduction of solid food in the fourth to the seventh month period of life. A delayed introduction of solid food after this period may increase the risk of developing subsequent allergic conditions. Further studies are encouraged to avoid unjustified recommendations involving useless dietary restrictions.

Nasal Hyperreactivity: Nonspecific Nasal Provocation Tests. Review by the Rhinoconjunctivitis Committee of the Spanish Society of Allergy and Clinical Immunology.

Nasal hyperreactivity is the abnormal reaction of nasal tissue to a stimulus that is innocuous to most people. This response is caused by dysregulation of the autonomic nervous system at various levels of the nasal autonomic reflex arc. Various stimuli (methacholine, histamine, adenosine 5'-monophosphate, cold air, mannitol, rapsaicin, phentolamine, and distilled water) have been used in an attempt to find the test that most reliably differentiates between healthy individuals and patients and also between different types of rhinitis. Despite the small number of publications available, in the present review, we provide an update on current nonspecific nasal provocation techniques. The studies published to date are not comparable: the stimuli applied act through different mechanisms and are used to assess different pathways, and the methodologies differ in terms of selection of participants, concentrations used, and assessment of response (criteria for positivity). Given the limited use of nonspecific nasal provocation tests in routine clinical practice, we believe that more studies are warranted to address the research issues we present at the end of the present review, for example, the need to standardize the methodology for each test or even the clinical benefits of knowing whether or not a patient has nasal hyperreactivity.

Consensus document on allergic conjunctivitis (DECA).

Allergic conjunctivitis (AC) is an inflammatory disease of the conjunctiva caused mainly by an IgE-mediated mechanism. It is the most common type of ocular allergy. Despite being the most benign form of conjunctivitis, AC has a considerable effect on patient quality of life, reduces work productivity, and increases health care costs. No consensus has been reached on its classification, diagnosis, or treatment. Consequently, the literature provides little information on its natural history, epidemiological data are scarce, and it is often difficult to ascertain its true morbidity. The main objective of the Consensus Document on Allergic Conjunctivitis (Documento dE Consenso sobre Conjuntivitis Alérgica [DECA]), which was drafted by an expert panel from the Spanish Society of Allergology and Spanish Society of Ophthalmology, was to reach agreement on basic criteria that could prove useful for both specialists and primary care physicians and facilitate the diagnosis, classification, and treatment of AC. This document is the first of its kind to describe and analyze aspects of AC that could make it possible to control symptoms.

[Study of the expression of neural stem cell markers in neuroblastoma tumor samples and correlation with prognostic factors]. / Estudio de expresión de marcadores de células madre neurales en neuroblastoma y correlación con factores pronóstico.

INTRODUCTION: The existence of cancer stem cells (CSC) in neuroblastoma (NB) has been associated with the development of metastasis, resistance to chemotherapy and recurrence. Our objective is to analyze the expression of proliferation and differentiation markers of neural progenitor cells in NB samples, and to correlate this expression with clinical variables such as histology, genetics and response to conventional therapy. MATERIAL AND METHODS: We performed a retrospective-experimental study with neuroblastoma samples obtained from biopsies or tumor resections between 2010-2012 in our Hospital. Fluorescence immunohistochemistry was used to analyze the expression of the different markers: CD44, CD74, CD133, tyrosine hydroxylase, endothelin receptors type A (ETA) and B (ETB), p75, nestina y and Phox2b, all of them related to neural stem cell biology. The level of expression of the markers was then correlated with clinical variables. RESULTS: Nestin expression was positive in 72.2% of samples and ETA in 66.7%. PHOX2B and CD74 expression were lower, being positive in less than 30%. The markers CD44, ETB and PHOX2B were expressed in more aggressive tumors. ETA expression correlated significantly with unfavorable histology tumors (p= 0.01), N-myc amplification (p= 0.05) and recurrence/progression (p= 0.05). CONCLUSION: The expression of CD44, ETB and ETA was associated with more aggressive tumors and poor prognostic factors. These markers are in the membrane of neural stem cells and may be useful to identify and isolate by flow cytometry CSCs of NB for the study of new therapeutic targets.

Progressive plasticity during colorectal cancer metastasis.

Metastasis is the principal cause of cancer death, yet we lack an understanding of metastatic cell states, their relationship to primary tumor states, and the mechanisms by which they transition. In a cohort of biospecimen trios from same-patient normal colon, primary and metastatic colorectal cancer, we show that while primary tumors largely adopt LGR5 + intestinal stem-like states, metastases display progressive plasticity. Loss of intestinal cell states is accompanied by reprogramming into a highly conserved fetal progenitor state, followed by non-canonical differentiation into divergent squamous and neuroendocrine-like states, which is exacerbated by chemotherapy and associated with poor patient survival. Using matched patient-derived organoids, we demonstrate that metastatic cancer cells exhibit greater cell-autonomous multilineage differentiation potential in response to microenvironment cues than their intestinal lineage-restricted primary tumor counterparts. We identify PROX1 as a stabilizer of intestinal lineage in the fetal progenitor state, whose downregulation licenses non-canonical reprogramming.

Erlotinib and chemoradiation in patients with surgically resected locally advanced squamous cell carcinoma of the head and neck: a GICOR phase I trial.

BACKGROUND: Standard treatment of advanced squamous cell carcinoma of the head and neck (SCCHN) is concurrent chemoradiation. Erlotinib is an oral tyrosine kinase inhibitor of epidermal growth factor receptor, which has shown activity in SCCHN. Phase I study aims to determine the maximum tolerated dose and dose-limiting toxicity (DLT) of adding erlotinib to chemoradiation therapy in patients with surgically resected locally advanced SCCHN. PATIENTS AND METHODS: Inclusion criteria--SCCHN patients with T3 or T4 primary lesion (except T3N0 with negative resection margins); pathologic N2-N3 disease; poor prognostic findings; age 18-70 years; Eastern Cooperative Oncology Group performance status of zero to one; no evidence of metastasis; adequate organic function and written informed consent. Study design--dose-escalating phase I study with three cohorts of three to six patients each that received increasing doses of erlotinib (100-150 mg/day p.o.) and cisplatin (30-40 mg/m(2) i.v., day 1) for 7 weeks. Radiotherapy--standard regimen of 1.8 Gy daily (5 fractions/week) to a maximum total dose of 63 Gy in 7 weeks. RESULTS: Thirteen male (median age: 57 years) were enrolled. Overall, the regimen was well tolerated. Two of three patients treated at dose level III (erlotinib: 150 mg/day; cisplatin: 40 mg/m(2)) developed DLT consisting of grade 3 infection and grade 3 mucositis. Other toxic effects included diarrhea, asthenia, and rash. Recommended dose for additional studies: erlotinib 150 mg/day p.o.; cisplatin 30 mg/m(2)/week i.v. CONCLUSION: Erlotinib can be safely combined with chemoradiation without requiring dose reduction of chemo- or radiotherapy in this postsurgical population.

Chitosan/poly(DL,lactide-co-glycolide) scaffolds for tissue engineering.

Chitosan/poly(DL-lactide-co-glycolide) (Ch/DL PLG) composite scaffolds were fabricated by freeze-drying lyophilization, and were evaluated and compared for use as a bone regeneration scaffold through measurements of the compression mechanical properties of the porous scaffolds. Also, In vitro cell culture of Sprague-Dawley rat's osteoblasts were used to evaluate the phenotype expression of cells in the scaffolds, characterizing the cellular adhesion, proliferation and alkaline phosphatase activity. The gene expression of osteocalcin, sialoprotein, alkaline phosphatase, Type I collagen and TGFß1 were confirmed in the samples; moreover, it was confirmed, the mineralization by IR spectra and EDS analysis. Our results thus show that Ch/DL PLG scaffolds are suitable for biological applications.

Resveratrol inhibits proliferation of primary rat hepatocytes in G0/G1 by inhibiting DNA synthesis.

Resveratrol is a phytoalexin that has been shown to inhibit cell proliferation of several cancer cell lines. In some cases this inhibition was specific for the transformed cells when compared with normal cells of the same tissue. To test whether this was the case in rat hepatocytes, we exposed primary rat hepatocytes in culture and transformed rat hepatic cells to this compound and studied its effect on cell proliferation, measuring deoxy-bromouridine incorporation and total DNA. We also studied the effect of resveratrol on the cell cycle of normal and transformed rat hepatocytes. We observed that resveratrol inhibited proliferation in a dose-dependent manner in both cases, with no differential action in the transformed cells compared to the normal ones. This compound arrested the cell cycle in G0/G1 in primary hepatocytes, while it arrested the cell cycle in G2/M in transformed cells. Transformed hepatocytes showed accumulation of cells in the S phase of the cell cycle.

Cost-utility analysis of ceftazidime-avibactam versus colistin-meropenem in the treatment of infections due to Carbapenem-resistant Klebsiella pneumoniae in Colombia.

BACKGROUND: Ceftazidime-Avibactam (CAZ-AVI) is a new antimicrobial against carbapenem-resistant Klebsiella pneumoniae. The aim of the study is to examine the cost-effectiveness of CAZ-AVI compared to colistin-meropenem (COL+MEM) in Colombia. METHODS: A decision tree model was developed from health-care system perspective assuming a 30-day time horizon. The clinical course was simulated based on treatment response between 48 and 72 hours, and the duration of the treatment was 7-14 days. Cost inputs were extracted from a published Colombian manual tariffs and official databases, expressed in 2019 dollars (USD). RESULTS: In the base case analysis, CAZ-AVI was associated with reduced mortality, length of hospital stay and fewer add-on antibiotics, resulting in an increase of 1.76 QALYs per patient versus COL+MEM and incremental costs associated in CAZ-AVI were $2,521 higher per patient compared to COL+MEM ($755 versus $3,276). The incremental costs were partially increased due to the lower mortality rate observed with CAZ-AVI. The incremental cost-effectiveness ratio was estimated to be $3,317 per QALY. In the probabilistic sensitivity analysis, with a willingness to pay above $2,438, CAZ-AVI has higher probability of being cost-effective. CONCLUSION: CAZ-AVI demonstrates cost-effectiveness as a treatment for Carbapenem-resistant Klepsiella pneumoniae infections by reducing the number of deaths and increasing QALYs. EXPERT COMMENTARY: Previous studies and surveillance programs from Colombia have reported prevalence of pathogens and the antimicrobial susceptibility of infections caused by multidrug-resistant Gram-negative bacteria. The health authorities have to consider and plan adequate surveillance systems in order to predict the resistance type and in choose the optimal antibiotics when infections occur.