Seasonal dietary changes relate to gut microbiota composition depending on the host species but do not correlate with gut microbiota diversity in arthropod-eating lizards.

The animal gut microbiota is strongly influenced by environmental factors that shape their temporal dynamics. Although diet is recognized as a major driver of gut microbiota variation, dietary patterns have seldom been linked to gut microbiota dynamics in wild animals. Here, we analysed the gut microbiota variation between dry and rainy seasons across four Sceloporus species (S. aeneus, S. bicanthalis, S. grammicus and S. spinosus) from central Mexico in light of temporal changes in diet composition. The lizard microbiota was dominated by Firmicutes (now Bacillota) and Bacteroidota, and the closely related species S. aeneus and S. bicanthalis shared a great number of core bacterial taxa. We report species-specific seasonal changes in gut microbiota diversity and composition: greater alpha diversity during the dry compared to the rainy season in S. bicanthalis, the opposite pattern in S. aeneus, and no seasonal differences in S. grammicus and S. spinosus. Our findings indicated a positive association between gut bacterial composition and dietary composition for S. bicanthalis and S. grammicus, but bacterial diversity did not increase linearly with dietary richness in any lizard species. In addition, seasonality affected bacterial composition, and microbial community similarity increased between S. aeneus and S. bicanthalis, as well as between S. grammicus and S. spinosus. Together, our results illustrate that seasonal variation and dietary composition play a role in shaping gut microbiota in lizard populations, but this is not a rule and other ecological factors influence microbiota variation.

Proteomic characterization of Tenacibaculum dicentrarchi under iron limitation reveals an upregulation of proteins related to iron oxidation and reduction metabolism, iron uptake systems and gliding motility.

A strategy for vaccine design involves identifying proteins that could be involved in pathogen-host interactions. The aim of this proteomic study was to determine how iron limitation affects the protein expression of Tenacibaculum dicentrarchi, with a primary focus on virulence factors and proteins associated with iron uptake. The proteomic analysis was carried out using two strains of T. dicentrarchi grown under normal (control) and iron-limited conditions, mimicking the host environment. Our findings revealed differences in the proteins expressed by the type strain CECT 7612T and the Chilean strain TdCh05 of T. dicentrarchi. Nonetheless, both share a common response to iron deprivation, with an increased expression of proteins associated with iron oxidation and reduction metabolism (e.g., SufA, YpmQ, SufD), siderophore transport (e.g., ExbD, TonB-dependent receptor, HbpA), heme compound biosynthesis, and iron transporters under iron limitation. Proteins involved in gliding motility, such as GldL and SprE, were also upregulated in both strains. A negative differential regulation of metabolic proteins, particularly those associated with amino acid biosynthesis, was observed under iron limitation, reflecting the impact of iron availability on bacterial metabolism. Additionally, the TdCh05 strain exhibited unique proteins associated with gliding motility machinery and phage infection control compared to the type strain. These groups of proteins have been identified as virulence factors within the Flavobacteriaceae family, including the genus Tenacibaculum. These results build upon our previous report on iron acquisition mechanisms and could lay the groundwork for future studies aimed at elucidating the role of some of the described proteins in the infectious process of tenacibaculosis, as well as in the development of potential vaccines.

MRI-based radiomic features for identifying recurrent prostate cancer after proton radiation therapy.

PURPOSE: Magnetic Resonance Imaging (MRI) evaluation of recurrent prostate cancer (PCa) following proton beam therapy is challenging due to radiation-induced tissue changes. This study aimed to evaluate MRI-based radiomic features so as to identify the recurrent PCa after proton therapy. METHODS: We retrospectively studied 12 patients with biochemical recurrence (BCR) following proton therapy. Two experienced radiologists identified prostate lesions from multi-parametric MRI (mpMRI) images post-proton therapy and marked control regions of interest (ROIs) on the contralateral side of the prostate gland. A total of 210 radiomic features were extracted from lesions and control regions on the T2-weighted (T2WI) and Apparent Diffusion Coefficient (ADC) image series. Recursive Feature Elimination with Cross-Validation method (RFE-CV) was used for feature selection. A Multilayer Perceptron (MLP) neural network was developed to classify three classes: cancerous, benign, and healthy tissue. The 12-core biopsy results were used as the gold standard for the segmentations. The classifier performance was measured using specificity, sensitivity, the area under receiver operating characteristic curve (AUC), and other statistical indicators. RESULTS: Based on biopsy results, 10 lesions were identified as PCa recurrence while eight lesions were confirmed to be benign. Ten radiomic features (10/210) were selected to build the multi-class classifier. The radiomics classifier gave an accuracy of 0.83 in identifying cancerous, benign, and healthy tissue with a sensitivity of 0.80 and specificity of 0.85. The model yielded an AUC of 0.87, 95% CI [0.72-1.00] in differentiating cancer from the benign and healthy tissues. CONCLUSIONS: Our proof-of-concept study demonstrates the potential of using radiomic features as part of the differential diagnosis of PCa on mpMRI following proton therapy. The results need to be validated in a larger cohort.

Discovery and Characterization of the ddx41 Gene in Atlantic Salmon: Evolutionary Implications, Structural Functions, and Innate Immune Responses to Piscirickettsia salmonis and Renibacterium salmoninarum Infections.

The innate immune response in Salmo salar, mediated by pattern recognition receptors (PRRs), is crucial for defending against pathogens. This study examined DDX41 protein functions as a cytosolic/nuclear sensor for cyclic dinucleotides, RNA, and DNA from invasive intracellular bacteria. The investigation determined the existence, conservation, and functional expression of the ddx41 gene in S. salar. In silico predictions and experimental validations identified a single ddx41 gene on chromosome 5 in S. salar, showing 83.92% homology with its human counterpart. Transcriptomic analysis in salmon head kidney confirmed gene transcriptional integrity. Proteomic identification through mass spectrometry characterized three unique peptides with 99.99% statistical confidence. Phylogenetic analysis demonstrated significant evolutionary conservation across species. Functional gene expression analysis in SHK-1 cells infected by Piscirickettsia salmonis and Renibacterium salmoninarum indicated significant upregulation of DDX41, correlated with increased proinflammatory cytokine levels and activation of irf3 and interferon signaling pathways. In vivo studies corroborated DDX41 activation in immune responses, particularly when S. salar was challenged with P. salmonis, underscoring its potential in enhancing disease resistance. This is the first study to identify the DDX41 pathway as a key component in S. salar innate immune response to invading pathogens, establishing a basis for future research in salmonid disease resistance.

Is Contrast-Enhanced Computed Tomography Redundant for Suspected Intracranial Infection in the Emergency Setting?

OBJECTIVE: There are currently no guidelines for when to use intravenous contrast with head computed tomography (CT) when there is suspected acute intracranial infection. The purpose of our study was to determine the proportion of cases with enhancing findings on CT that also have conspicuous correlating associated findings on noncontrast CT, which would have on their own merited further evaluation with magnetic resonance imaging, the criterion standard for evaluating central nervous system pathology. METHODS: A retrospective keyword search of the history and clinical information fields in radiology reports for CT examinations of the head without and with contrast from the period January 1, 2004, to October 31, 2021 was performed. Patients with prior head surgery or a history of cancer were excluded. For remaining patients, the noncontrast CT was reviewed for vasogenic edema or mass effect as markers of a possible acute infection, and the presence of background hypodense white matter changes was noted and graded as either absent, mild/scattered, or confluent. Subsequently, the companion contrast-enhanced CT was reviewed for an enhancing abnormality. Chart review was performed to confirm that an infectious process was the ultimate clinical diagnosis in patients with enhancing abnormalities. RESULTS: Of 343 patients meeting study inclusion/exclusion criteria, 39 had acute infections with an enhancing abnormality on CT (prevalence 11.3%). Thirty-two of these 39 patients also had correlative findings on the noncontrast CT. Noncontrast CT had a positive predictive value of 100%, negative predictive value of 97.7%, sensitivity of 82.1%, specificity of 100%, and accuracy of 98.0% for detecting markers (vasogenic edema and/or mass effect) associated with an enhancing abnormality. Vasogenic edema was the most common noncontrast CT finding in patients who had an infectious enhancing lesion (32 of 39), followed by mass effect (22 of 39). The 7 cases where the acute infection was occult on noncontrast CT were due to leptomeningitis (n = 3), confluent background white matter changes masking the vasogenic edema surrounding intra-axial lesions (n = 3), and a small 0.5 cm extra-axial abscess. CONCLUSIONS: Most acute intracranial infections with an enhancing CT finding also have a correlative conspicuous noncontrast finding that on its own would merit further evaluation with magnetic resonance imaging, the criterion standard for investigating central nervous system disease, and therefore, in the setting of suspected intracranial infection, contrast-enhanced CT is redundant in most cases. Contrast-enhanced CT primarily provides diagnostic benefit in patients with confluent background white matter changes that may mask vasogenic edema on noncontrast CT.

Can Anterior Osteophyte Fractures Be Distinguished From Fracture Mimics in the Subaxial Cervical Spine? A Retrospective Analysis Evaluating Reported Fractures With Clinical Management Correlation.

OBJECTIVE: This study aimed to retrospectively distinguish true- from false-positive fractures of anterior subaxial cervical osteophytes, which were reported on noncontrast computed tomography reports, and to correlate the imaging findings with patient symptoms and analyze the downstream impact on management of both true and false positive fractures. METHODS: A total of 127 patients had computed tomography reports of anterior osteophyte fractures. Radiology reports and imaging studies were evaluated to distinguish true fractures from fracture mimics. We analyzed imaging features including rigid spine (RS), prevertebral soft tissue swelling (PVSTS), and instability. We categorized symptoms and examination findings into 3 groups (0, asymptomatic; 1, neck pain; 2, neurological symptoms). Management was categorized into 3 groups (0, no treatment; 1, external bracing; 2, surgery). Associations between imaging features, fracture classification, clinical symptoms, magnetic resonance imaging utilization, and management were calculated using χ2 with Cramer V test to determine effect size. RESULTS: Eighty patients had false-positive fractures, and 47 were true positive. There were significant associations between magnetic resonance imaging utilization and fracture classification (P ≤ 0.001), PVSTS (P ≤ 0.005), patient symptoms (P ≤ 0.001), and patient management (P ≤ 0.001). There were significant associations between patient management and fracture classification (P ≤ 0.001), patient symptoms (P ≤ 0.001), PVSTS (P ≤ 0.001), imaging findings of instability (P ≤ 0.001), and RS (P ≤ 0.021). There were significant associations between fracture classification and patient symptoms (P ≤ 0.045), and RS (P ≤ 0.006). CONCLUSIONS: Subaxial isolated anterior osteophyte fractures fell into 3 major categories. By our methodology, if a suspected fracture was determined to be a fracture mimic in an asymptomatic patient, it was unlikely to be clinically significant. Isolated anterior osteophyte fractures without neurological symptoms or more concerning imaging findings can be treated conservatively. Finally, fractures that demonstrate indirect signs of instability or are associated with RS are more associated with surgical management.

Improved ß2-Microglobulin and Phosphorous Removal with Expanded Hemodialysis and Online Hemodiafiltration versus High-Flux Hemodialysis: A Cross-Over Randomized Clinical Trial.

INTRODUCTION: Expanded hemodialysis (HDx) is expected to provide enhanced permeability of medium-sized molecules, selective solute retention, and better internal retrofiltration. The primary objective of this study was to compare the efficiency for removal of ß2-microglobulin with 3 different extracorporeal therapies (ETs): high-flux hemodialysis (HF), online hemodiafiltration (OL-HDF), and HDx. The secondary objective was to evaluate the efficiency of removal of other uremic toxins, including urea, phosphate, CRP, IL-6, IL-10, TNF-⍺, indoxyl sulfate, and p-cresol. METHODS: This single-center, randomized, and cross-over study was performed. Patients were randomized to determine the initial modality of treatment, each period lasted 4 weeks and between one modality and another, there was a washout period of 1 week. Reduction ratios (RRs) of different-size molecules and albumin were calculated for the different ET. RESULTS: Twenty-two patients were included, ß2-microglobulin RR was greater during both OL-HDF and HDx as compared to HF (RR 62% vs. 73% vs. 27%, respectively, p = <0.0001), and there was no significant difference between HDx and OL-HDF (p = 0.09). A decrease in serum phosphate levels was observed in the HDx and OL-HDF periods, contrary to an increase in HF (-0.79 mg/dL vs. -1.02 mg/dL vs. + 0.11 mg/dL, respectively, p = <0.0001). There was no difference in RRs of other molecules (BUN, CRP, IL-6, IL-10, TNF-⍺, indoxyl sulfate, and p-Cresol). There was no decrease in serum albumin in any ET. CONCLUSION: HDx provides enhanced removal of ß2-microglobulin and phosphate as compared to HF, and similar efficacy as with OL-HDF. HDx should be considered an alternative to chronic convective therapies.

Are medium cut-off membranes the future, or the promising reality for chronic hemodialysis patients?

The development of hemodialysis (HD) membranes has substantially advanced in the last decade. This has resulted in the manufacturing of medium cut-off membranes (MCO) whose internal architecture is based on greater pore size and a smaller diameter, thus promoting the clearance of particles of greater size as well as retrofiltration. Multiple studies have proven their efficacy in the clearance of uremic mid-sized molecules such as ß2-microglobulin, free light chains, and some interleukins; this clearance is far superior with MCO membranes when compared with high-flux HD, and similar to that obtained with online hemodiafiltration. This review summarizes the results of the most relevant clinical studies of this membrane in terms of uremic toxin clearance, as well as the features of some clinical outcomes such as quality of life and hospitalizations.

Proteomic analysis reveals Renibacterium salmoninarum grown under iron-limited conditions induces iron uptake mechanisms and overproduction of the 57-kDa protein.

Renibacterium salmoninarum, a slow-growing facultative intracellular pathogen, is the causative agent of bacterial kidney disease, a chronic, progressive and granulomatous infection that threatens farmed and wild salmonids worldwide. Pathogenic R. salmoninarum colonizes tissues and invades the host through cell surface-associated and secreted proteins. While correlations between iron acquisition genes and virulence have been demonstrated in vitro, these mechanisms have not undergone proteomic characterization. The present study applied a proteomic approach to elucidate the differences between the virulent Chilean R. salmoninarum H-2 strain and the type strain ATCC 33209T . Analyses were conducted under normal (control) and iron-limited conditions (DIP) emulating the host environment. Interestingly, strain H-2 apparently responded better to the iron-limited condition-for example, only this strain presented a significantly enriched iron ion homeostasis pathway. Furthermore, key virulence factors related to an iron-limited environment were more abundant in strain H-2. Importantly, the lack of iron favoured the expression of the 57-kDa protein in strain H-2, the principal virulence factor for R. salmoninarum. Our findings can be employed in the design and development of treatments targeted to iron uptake mechanisms (e.g. siderophore synthesis or haem uptake), which represents a promising therapeutic approach for treating this persistent fastidious bacterium.

Imaging of dental infections.

Dental infections are a common presentation in the emergency department (ED). To help guide clinical management for these infections, the radiologist must be familiar with the anatomy of the oral cavity and neighboring structures, the range of appearance of dental infections, and the routes along which they may spread. Computed tomography (CT) is often performed when severe dental infections are suspected. This pictorial essay reviews the anatomy pertinent to the imaging evaluation of dental infections and depicts a spectrum of pathology that may be encountered, ranging from simple dentoalveolar infections to complex multispatial infections.

Analysis of Tumor-Infiltrating T-Cell Transcriptomes Reveal a Unique Genetic Signature across Different Types of Cancer.

CD8+ and CD4+ T-cells play a key role in cellular immune responses against cancer by cytotoxic responses and effector lineages differentiation, respectively. These subsets have been found in different types of cancer; however, it is unclear whether tumor-infiltrating T-cell subsets exhibit similar transcriptome profiling across different types of cancer in comparison with healthy tissue-resident T-cells. Thus, we analyzed the single cell transcriptome of five tumor-infiltrating CD4-T, CD8-T and Treg cells obtained from different types of cancer to identify specific pathways for each subset in malignant environments. An in silico analysis was performed from single-cell RNA-sequencing data available in public repositories (Gene Expression Omnibus) including breast cancer, melanoma, colorectal cancer, lung cancer and head and neck cancer. After dimensionality reduction, clustering and selection of the different subpopulations from malignant and nonmalignant datasets, common genes across different types of cancer were identified and compared to nonmalignant genes for each T-cell subset to identify specific pathways. Exclusive pathways in CD4+ cells, CD8+ cells and Tregs, and common pathways for the tumor-infiltrating T-cell subsets were identified. Finally, the identified pathways were compared with RNAseq and proteomic data obtained from T-cell subsets cultured under malignant environments and we observed that cytokine signaling, especially Th2-type cytokine, was the top overrepresented pathway in Tregs from malignant samples.

What did we learn about coronavirus disease-19-associated acute kidney injury during the pandemic?

Initial reports suggested that kidney involvement after coronavirus disease 19 (COVID-19) infection was uncommon, but this premise appears to be incorrect. Acute kidney injury can occur through various mechanisms and complicate the course of up to 25% of patients with COVID-19 hospitalized in our Institution, and of over 50% of those on invasive mechanical ventilation. Mechanisms of injury include direct kidney injury and predominantly tubular, although glomerular injury has been reported, and resulting from severe hypoxic respiratory failure, secondary infection, and exposure to nephrotoxic drugs. The mainstay of treatment remains the prevention of progressive kidney damage and, in some cases, the use of renal replacement therapy. Although the use of blood purification techniques has been proposed as a potential treatment, results to date have not been conclusive. In this manuscript, the mechanisms of kidney injury by COVID-19, risk factors, and the mainstays of treatment are reviewed.

Importance of Confirmatory Tests for Sars-Cov-2 Infection in Hemodialysis Patients: A Multicenter Mexican Registry.

Background: Since the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, patients with chronic kidney disease vulnerable to suffering more severe COVID-19 disease and worse outcomes have been identified. Objectives: Our study's aim was to determine the incidence, characteristics, and outcomes of SARS-CoV-2 infection in patients of hemodialysis (HD) units in Mexico and to describe the availability of confirmatory testing. Methods: This study was multicentric study of 19 HD units, conducted between March 2020 and March 2021. Results: From a total of 5779 patients, 955 (16.5%) cases of suspicious COVID-19 were detected; a SARS-CoV-2 reverse transcription polymerase chain reaction test was done in only 50.6% of patients. Forty-five percentages were hospitalized and 6% required invasive mechanical ventilation (IMV). There was no significant difference in mortality between confirmed (131/483) and suspicious (124/472) cases (p = 0.74). The percentage of patients in need of hospitalization, IMV, and deceased was greater than in the rest of the study population. Conclusions: The study revealed that 49.4% of the cases were not confirmed, a worrisome observation given that this is a highly vulnerable population (higher probability of contagion and worse outcomes), in which 100% of patients should have a confirmatory test.

Prolonged Intermittent Renal Replacement Therapy for Acute Kidney Injury in COVID-19 Patients with Acute Respiratory Distress Syndrome.

INTRODUCTION: Patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19 frequently develop severe acute kidney injury (AKI). Although continuous renal replacement therapy is the standard of care for critically ill patients, prolonged intermittent renal replacement therapy (PIRRT) may be a feasible option. We aimed to describe the tolerability and security of PIRRT treatments in COVID-19 patients with ARDS who required mechanical ventilation and developed severe AKI. METHODS: We prospectively analyzed patients who underwent PIRRT treatments at a COVID-19 reference hospital in Mexico City. Intradialytic hypotension was defined as a systolic blood pressure decrease of ≥20 mm Hg or an increase of 100% in vasopressor dose. RESULTS: We identified 136 AKI cases (60.7%) in 224 patients admitted to the intensive care unit. Among them, 21 (15%) underwent PIRRT (130 sessions) due to stage 3 AKI. The median age of the cohort was 49 (range 36-73) years, 17 (81%) were male, 7 (33%) had diabetes, and the median time between symptoms onset and PIRRT initiation was 12 (interquartile range [IQR] 7-14) days. The median of PIRRT procedures for each patient was 5 (IQR 4-9) sessions. In 108 (83%) PIRRT sessions, the total ultrafiltration goal was achieved. In 84 (65%) PIRRT procedures, there was a median increase in norepinephrine dose of +0.031 mcg/kg/min during PIRRT (IQR 0.00 to +0.07). Intradialytic hypotensive events occurred in 56 (43%) procedures. Fifteen (12%) PIRRT treatments were discontinued due to severe hypotension. Vasopressor treatment at PIRRT session onset (OR 6.2, 95% CI 1.4-28.0, p: 0.02) and a pre-PIRRT lactate ≥3.0 mmol/L (OR 4.63, 95% CI 1.3-12.8, p: 0.003) were independently and significantly associated with the risk of hypotension during PIRRT. During follow-up, 11 patients (52%) recovered from AKI and respiratory failure and 9 (43%) died. Several adaptations to our PIRRT protocol during the COVID-19 outbreak are presented. CONCLUSIONS: PIRRT was feasible in the majority of COVID-19 patients with ARDS and severe AKI, despite frequent transitory intradialytic hypotensive episodes. PIRRT may represent an acceptable alternative of renal replacement therapy during the COVID-19 outbreak.

Community- and Hospital-Acquired Acute Kidney Injury in COVID-19: Different Phenotypes and Dismal Prognosis.

INTRODUCTION: Acute kidney injury (AKI) is common in coronavirus disease 2019 (COVID-19). It is unknown if hospital-acquired AKI (HA-AKI) and community-acquired AKI (CA-AKI) convey a distinct prognosis. METHODS: The study aim was to evaluate the incidence and risk factors associated with both CA-AKI and HA-AKI. Consecutive patients hospitalized at a reference center for COVID-19 were included in this prospective cohort study. RESULTS: We registered 349 (30%) AKI episodes in 1,170 hospitalized patients, 224 (19%) corresponded to CA-AKI, and 125 (11%) to HA-AKI. Compared to patients with HA-AKI, subjects with CA-AKI were older (61 years [IQR 49-70] vs. 50 years [IQR 43-61]), had more comorbidities (hypertension [44 vs. 26%], CKD [10 vs. 3%]), higher Charlson Comorbidity Index (2 points [IQR 1-4] vs. 1 point [IQR 0-2]), and presented to the emergency department with more severe disease. Mortality rates were not different between CA-AKI and HA-AKI (119 [53%] vs. 63 [50%], p = 0.66). In multivariate analysis, CA-AKI was strongly associated to a history of CKD (OR 4.17, 95% CI 1.53-11.3), hypertension (OR 1.55, 95% CI 1.01-2.36), Charlson Comorbidity Index (OR 1.16, 95% CI 1.02-1.32), and SOFA score (OR 2.19, 95% CI 1.87-2.57). HA-AKI was associated with the requirement for mechanical ventilation (OR 68.2, 95% CI 37.1-126), elevated troponin I (OR 1.95, 95% CI 1.01-3.83), and glucose levels at admission (OR 1.05, 95% CI 1.02-1.08). DISCUSSION/CONCLUSIONS: CA-AKI and HA-AKI portend an adverse prognosis in CO-VID-19. Nevertheless, CA-AKI was associated with a higher comorbidity burden (including CKD and hypertension), while HA-AKI occurred in younger patients by the time severe multiorgan disease developed.

[Prevention and control of SARS-CoV-2 (Covid-19) coronavirus infection in hemodialysis units.] / Prevención y control de la infección por coronavirus SARS-CoV-2 (Covid-19) en unidades de hemodiálisis.

The SARS-CoV-2 pandemic is of hich risk for patients on chronic hemodialysis due to their immunosuppressed state, advanced age, and the coexistence of significant comorbidities, in particular cardiovascular disease, diabetes mellitus, and others. Additionally, they constitute a closed conglomerate since they come to treatment regularly, spending hours in the treatment places, exposed to a possible acquisition of the infection. Finally, going to their treatment regularly prevents them from remaining in home isolation and with potential exposure. These recommendations summarize the interventions proposed by three international organizations and add some suggested by national experts, with the aim to early identify the patients and health personnel at risk and reducing the risk of infection.

La pandemia del SARS-CoV-2 representa un riesgo especial para los pacientes en hemodiálisis crónica por su estado de inmunosupresión, edad avanzada y coexistencia de comorbilidades importantes, en particular patología cardiovascular, diabetes mellitus y otras. Adicionalmente, esta población constituye un conglomerado cerrado ya que los pacientes acuden a tratamiento con regularidad y permanecen horas en los lugares de tratamiento, expuestos a una posible adquisición de la infección. El hecho de acudir necesaria y regularmente a su tratamiento impide que permanezcan en aislamiento domiciliario y con exposición potencial en el traslado. Las presentes recomendaciones resumen las intervenciones propuestas por tres organizaciones internacionales, a las que se agregan algunas sugeridas por expertos nacionales, con el objetivo de identificar precozmente a los pacientes y personal de la salud en riesgo para disminuir el riesgo de infección.

In vitro expression of Sec-dependent pathway and type 4B secretion system in Piscirickettsia salmonis.

Piscirickettsia salmonis is an intracellular bacterium and the causative agent of Piscirickettsiosis, a disease responsible for considerable mortalities in the Chilean salmon farming industry. Currently, P. salmonis protein translocation across the membrane and the mechanisms by which virulence factors are delivered to host cells are poorly understood. However, it is known that Gram-negative bacteria possess several mechanisms that transport proteins to the periplasmic and extracellular compartments. The aim of this study was to evaluate the expressional changes of several genes in the P. salmonis Sec-dependent pathway and type 4B secretion system during in vitro infection. Genes homologous and the main proteins belonging to Sec-dependent pathway and Type 4 Dot/Icm secretion system were found in the genome and proteome of P. salmonis AUSTRAL-005 strain. Additionally, several genes of these protein transport mechanisms were overexpressed during in vitro P. salmonis infection in SHK-1 cell line. The obtained data indicate that the Sec-dependent pathway and Type 4B secretion system are biologically active during P. salmonis infection. These mechanisms could contribute to the recycling of proteins into the inner and outer bacterial membrane and in translocate virulence factors to infected cell, which would favor the structural integrity and virulence of this bacterium.

Incidence of Guillain-Barré syndrome in Chile: a population-based study.

The Guillain-Barré syndrome (GBS) incidence rate (IR) varies between 0.16 and 3.00 cases per 100,000 inhabitants. Little data exist on the epidemiology of GBS in Latin American countries. Our objective was to describe GBS epidemiology based on a national database in a Latin American country and to contribute to the global map of GBS epidemiology. This was a retrospective study that included all reported GBS cases in Chile between 2001 and 2012. Gender, age, seasonal occurrence, and geographical distribution were analyzed. A total of 4,158 GBS cases were identified from 19,513,655 registries. The mean age was 37 ± 24 years, and 59% of patients were male (male to female ratio of 1.5 : 1). Gender IR was 2.53/100,000 for males and 1.68/100,000 for females. The overall standardized IR was 2.1/100,000, although this varied between 1.61/100,000 (2001) and 2.35/100,000 (2010). The seasonal distribution was as follows: autumn 22%; winter 25%; spring 27%; and summer 26%. The geographical IR were as follows: far North 1.49/100,000; North 1.94/100,000; Central 1.97/100,000; South 3.18/100,000; and far South 2.78/100,000. The reported IR of GBS in Chile was similar to other studies based on national databases. In Chile, IR was greater in men and in the south.

[Methodological bases and implementation results of Mexico's National Survey of Children and Women 2015]. / Bases metodológicas y resultados de la implementación de la Encuesta Nacional de Niños, Niñas y Mujeres en México 2015.

OBJECTIVE:: To describe the methodology and the implementation survey results from National Survey of Children and Women Mexico's (ENIM 2015). MATERIALS AND METHODS:: The ENIM 2015 is a probability survey with multistage, stratified and cluster sample, with regional, rural and urban strata, and indigenous population representation.We applied questionnaires to get information from the household, women aged 15 to 49 years, children under five years and children and adolescents aged 5-17 years. RESULTS:: The response rate for households and women was 94%, obtaining information from 10 760 households and 12 110 women; while for children and adolescents and children under five years was 98%, 11 607 and 8 066, respectively. CONCLUSION:: The ENIM 2015 probabilistic design allows generate indicators that can be stratified into five regions, rural and urban strata and from indigenous population, as well as a baseline for 15 indicators of the ODS.

Specimen self-collection and HPV DNA screening in a pilot study of 100,242 women.

Since cervical cancer remains common in Mexico despite an established cytology screening program, the Ministry of Health recently introduced pilot front-line HPV testing into the Mexican cervical cancer screening program (CCSP). Here, we present the key field performance metrics of this population-based study. High-risk HPV DNA (hrHPV) testing was conducted on self-collected vaginal specimens from 100,242 women aged 25-75 years residing in Morelos State. All hrHPV positive women and a random sample of 3.2% (n = 2,864) of hrHPV negative participants were referred for colposcopic examination. The main disease endpoint of interest was cervical intraepithelial neoplasia grade 2 or higher (CIN2+). We calculated relative risk, positive predictive value and negative predictive value adjusted for screening test verification bias. The overall prevalence of hrHPV was 10.8% (95% CI 10.6-11.0). Women positive for hrHPV had a relative risk of 15.7 for histologically detectable CIN2+. The adjusted positive predictive value of the hrHPV test was 2.4% (95% CI 2.1-2.7); whereas the adjusted negative predictive value was 99.8% (95% CI 99.8-99.9). These findings suggest that large-scale vaginal hrHPV testing in a middle-income country can identify women at greater risk of advanced cervical abnormalities in a programmatically meaningful way but care is warranted to ensure that disease not detectable at colposcopy is kept to a minimum. PASS shows areas that need improvement and sets the stage for wider use of hrHPV screening of self-collected vaginal specimens in Mexico.