SEOM clinical guidelines for the prophylaxis of infectious diseases in cancer patients (2021).

Infections are still a major cause of morbi-mortality in patients with cancer. Some of these infections are preventable through specific measures, such as vaccination or prophylaxis. This guideline aims to summarize the evidence and recommendations for the prevention of infections in cancer patients, devoting special attention to the most prevalent preventable infectious disease. All the evidences will be graded according to The Infectious Diseases Society of America grading system.

Identification of single nucleotide polymorphisms (SNPs) for maize cell wall hydroxycinnamates using a multi-parent advanced generation intercross (MAGIC) population.

Higher hydroxycinnamate content makes maize tissues more recalcitrant to damage by insects, less digestible by ruminants, and less suitable for biofuel production. In a Genome Wide Association Analysis (GWAS) study carried out in a maize MAGIC population, we identified 24 SNPs associated with esterified cell wall-bound hydroxycinnamates, that represented 15 Quantitative Traic Loci (QTL). We identified new genomic regions associated to cell wall bound hydroxycinnamates in maize stover that could have an impact on their content across different genetic backgrounds. The high resolution QTL described in this study could be valuable for addressing positional mapping of genes involved in hydroxycinnamate biosynthesis and could uncover genes implicated in the esterification of hydroxycinnamic acids to the arabinoxylan chains that are poorly understood. However, we found that genetic correlation coefficients between hydroxycinnamate content and economical important traits such as saccharification efficiency, animal digestibility andi pest resistance were low to moderate, so modify specific hydroxycinnamates to indirectly improve cultivar performance will be unsuitable.

COVID-19 patients with increasing age experience differential time to initial medical care and severity of symptoms.

We conducted a retrospective observational study in patients with laboratory-confirmed coronavirus disease (COVID-19) who received medical care in 688 COVID-19 ambulatory units and hospitals in Mexico City between 24 February 2020 and 24 December 2020, to study if the elderly seek medical care later than younger patients and their severity of symptoms at initial medical evaluation. Patients were categorised into eight groups (<20, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79 and ≥80 years). Symptoms at initial evaluation were classified according to a previously validated classification into respiratory and non-respiratory symptoms. Comparisons between time from symptom onset to medical care for every age category were performed through variance analyses. Logistic regression models were applied to determine the risk of presenting symptoms of severity according to age, and mortality risk according to delays in medical care. In total, 286 020 patients were included (mean age: 42.8, s.d.: 16.8 years; 50.4% were women). Mean time from symptom onset to medical care was 4.04 (s.d.: 3.6) days and increased with older age categories (P < 0.0001). Mortality risk increased by 6.4% for each day of delay in medical care from symptom onset. The risk of presenting with the symptoms of severity was greater with increasing age categories. In conclusion, COVID-19 patients with increasing ages tend to seek medical care later, with higher rates of symptoms of severity at initial presentation in both ambulatory units and hospitals.

Obesity is a strong risk factor for short-term mortality and adverse outcomes in Mexican patients with COVID-19: a national observational study.

Conflicting results have been obtained through meta-analyses for the role of obesity as a risk factor for adverse outcomes in patients with coronavirus disease-2019 (COVID-19), possibly due to the inclusion of predominantly multimorbid patients with severe COVID-19. Here, we aimed to study obesity alone or in combination with other comorbidities as a risk factor for short-term all-cause mortality and other adverse outcomes in Mexican patients evaluated for suspected COVID-19 in ambulatory units and hospitals in Mexico. We performed a retrospective observational analysis in a national cohort of 71 103 patients from all 32 states of Mexico from the National COVID-19 Epidemiological Surveillance Study. Two statistical models were applied through Cox regression to create survival models and logistic regression models to determine risk of death, hospitalisation, invasive mechanical ventilation, pneumonia and admission to an intensive care unit, conferred by obesity and other comorbidities (diabetes mellitus (DM), chronic obstructive pulmonary disease, asthma, immunosuppression, hypertension, cardiovascular disease and chronic kidney disease). Models were adjusted for other risk factors. From 24 February to 26 April 2020, 71 103 patients were evaluated for suspected COVID-19; 15 529 (21.8%) had a positive test for SARS-CoV-2; 46 960 (66.1%), negative and 8614 (12.1%), pending results. Obesity alone increased adjusted mortality risk in positive patients (hazard ratio (HR) = 2.7, 95% confidence interval (CI) 2.04-2.98), but not in negative and pending-result patients. Obesity combined with other comorbidities further increased risk of death (DM: HR = 2.79, 95% CI 2.04-3.80; immunosuppression: HR = 5.06, 95% CI 2.26-11.41; hypertension: HR = 2.30, 95% CI 1.77-3.01) and other adverse outcomes. In conclusion, obesity is a strong risk factor for short-term mortality and critical illness in Mexican patients with COVID-19; risk increases when obesity is present with other comorbidities.

Development and validation of the patient history COVID-19 (PH-Covid19) scoring system: a multivariable prediction model of death in Mexican patients with COVID-19.

Most of the existing prediction models for COVID-19 lack validation, are inadequately reported or are at high risk of bias, a reason which has led to discourage their use. Few existing models have the potential to be extensively used by healthcare providers in low-resource settings since many require laboratory and imaging predictors. Therefore, we sought to develop and validate a multivariable prediction model of death in Mexican patients with COVID-19, by using demographic and patient history predictors. We conducted a national retrospective cohort study in two different sets of patients from the Mexican COVID-19 Epidemiologic Surveillance Study. Patients with a positive reverse transcription-polymerase chain reaction for SARS-CoV-2 and complete unduplicated data were eligible. In total, 83 779 patients were included to develop the scoring system through a multivariable Cox regression model; 100 000, to validate the model. Eight predictors (age, sex, diabetes, chronic obstructive pulmonary disease, immunosuppression, hypertension, obesity and chronic kidney disease) were included in the scoring system called PH-Covid19 (range of values: -2 to 25 points). The predictive model has a discrimination of death of 0.8 (95% confidence interval (CI) 0.796-0.804). The PH-Covid19 scoring system was developed and validated in Mexican patients to aid clinicians to stratify patients with COVID-19 at risk of fatal outcomes, allowing for better and efficient use of resources.

Prospective, multicenter study on the economic and clinical impact of gene-expression assays in early-stage breast cancer from a single region: the PREGECAM registry experience.

INTRODUCTION: The aim of this study is to evaluate the cost-effectiveness and impact of gene-expression assays (GEAs) on treatment decisions in a real-world setting of early-stage breast cancer (ESBC) patients. METHODS: This is a regional, prospective study promoted by the Council Health Authorities in Madrid. Enrolment was offered to women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, node-negative or micrometastatic, stage I or II breast cancer from 21 hospitals in Madrid. Treatment recommendations were recorded before and after knowledge of tests results. An economic model compared the cost-effectiveness of treatment, guided by GEAs or by common prognostic factors. RESULTS: 907 tests (440 Oncotype DX® and 467 MammaPrint®) were performed between February 2012 and November 2014. Treatment recommendation changed in 42.6% of patients. The shift was predominantly from chemohormonal (CHT) to hormonal therapy (HT) alone, in 30.5% of patients. GEAs increased patients' confidence in treatment decision making. Tumor grade, progesterone receptor positivity and Ki67 expression were associated with the likelihood of change from CHT to HT (P < 0.001) and from HT to CHT (P < 0.001). Compared with current clinical practice genomic testing increased quality-adjusted life years by 0.00787 per patient and was cost-saving from a national health care system (by 13.867€ per patient) and from a societal perspective (by 32.678€ per patient). CONCLUSION: Using GEAs to guide adjuvant therapy in ESBC is cost-effective in Spain and has a significant impact on treatment decisions.

Long-lasting, reversible and non-neurotoxic inactivation of hippocampus activity induced by neosaxitoxin.

BACKGROUND: Neosaxitoxin (NeoSTX) and related paralytics shellfish toxins has been successfully used as local anesthetic and muscle relaxants to treat a variety of ailments. The primary mechanism of action of these toxins occurs by blocking voltage-gated sodium channels with compounds such as TTX, lidocaine, or derivatives. However, most of these non-classical sodium channel blockers act with a reduced time effect as well as ensuing neurotoxicity. NEW METHOD: In this report, we show that the use of local NeoSTX injections inactivates the hippocampal neuronal activity reversibly with a by long-term dynamics, without neuronal damage. RESULTS: A single 10 ng/µl injection of NeoSTX in the dorsal CA1 region abolished for up to 48 h memory capacities and neuronal activity measured by the neuronal marker c-fos. After 72 h of toxin injection, the animals fully recover their memory capacities and hippocampal neuronal activity. The histological inspection of NeoSTX injected brain regions revealed no damage to the tissue or reactive gliosis, similar to vehicle injection. Acute electrophysiological recording in vivo shows, also, minimal spreading of the NeoSTX in the cerebral tissue. COMPARISON WITH EXISTING METHODS: Intracerebral NeoSTX injection showed longer effects than other voltage sodium channel blocker, with minimal spreading and no neuronal damage. CONCLUSION: NeoSTX is a new useful tool that reversibly inactivates different brains region for a long time, with minimal diffusion and without neuronal damage. Moreover, NeoSTX can be used as a valuable sodium channel blocker for many studies in vivo and with potential therapeutic uses.

Interpreting the genomic landscape of speciation: a road map for finding barriers to gene flow.

Speciation, the evolution of reproductive isolation among populations, is continuous, complex, and involves multiple, interacting barriers. Until it is complete, the effects of this process vary along the genome and can lead to a heterogeneous genomic landscape with peaks and troughs of differentiation and divergence. When gene flow occurs during speciation, barriers restricting gene flow locally in the genome lead to patterns of heterogeneity. However, genomic heterogeneity can also be produced or modified by variation in factors such as background selection and selective sweeps, recombination and mutation rate variation, and heterogeneous gene density. Extracting the effects of gene flow, divergent selection and reproductive isolation from such modifying factors presents a major challenge to speciation genomics. We argue one of the principal aims of the field is to identify the barrier loci involved in limiting gene flow. We first summarize the expected signatures of selection at barrier loci, at the genomic regions linked to them and across the entire genome. We then discuss the modifying factors that complicate the interpretation of the observed genomic landscape. Finally, we end with a road map for future speciation research: a proposal for how to account for these modifying factors and to progress towards understanding the nature of barrier loci. Despite the difficulties of interpreting empirical data, we argue that the availability of promising technical and analytical methods will shed further light on the important roles that gene flow and divergent selection have in shaping the genomic landscape of speciation.

Analysis of the kinematic variation of human gait under different walking conditions using computer visión / Análisis de la variación cinemática de la marcha humana bajo diversas condiciones de caminado usando visión por computadora

ABSTRACT: This paper presents the analysis of human gait of three young adults under several walking conditions similar to those in real life. The aim is to evaluate how the human gait varies when different walking conditions are considered. In order to evaluate the human gait variations under different walking conditions, first a 3D computer visión system to reconstruct human gaits is developed and presented. Then, a set of kinematic gait parameters is defined in order to analyse the different gait patterns. Finally, several experiments are conducted with three normal Young adults walking under different real-life conditions, such as ascending a slope walk, no arm-swing walk, carrying a front load walk, carrying a lateral load walk, fast walk and high-heel shoes walk. The results has shown that the human gait pattern vary according to the walking conditions, being the most common variation a slower walk with shorter steps than the normal walk. Since the aim of the paper is to identify and evaluate human gait variations under different walking conditions, only three subjects were considered in the study. However, in order to provide more precise and standard results the number of subjects must be increased considering different age, height, sex, weight, and health conditions of the participants. Human walking patterns are very important for medical diagnosis and orthopedics, pathological and aging evaluation, medical rehabilitation, and design of rehabilitation systems, human prosthesis and humanoid robots. However, most of the research work in the literature has been primarily focused on the analysis of gait patterns under normal walking conditions. This fact has led to a limited knowledge of the human gait patterns since real-life walking conditions are diverse, e.g. walking carrying a load. This paper presents the analysis of human gait of three young adults under walking conditions similar to those in real life. Human gait patterns vary with the walking conditions, which must be considered during the analysis, evaluation and diagnosis of gait performance, or during the design process of prostheses or rehabilitation systems.

RESUMEN: En este artículo se presenta el análisis del patrón de caminado de tres adultos jóvenes bajo diversas condiciones de caminado tal como se presentan en la vida real. El objetivo es determinar la variación del patrón de caminado cuando se tienen diferentes condiciones de caminado. Con el propósito de evaluar la variación del patrón de caminado bajo diversas condiciones de caminado, primero se desarrolla y presenta un sistema de visión por computadora para la reconstrucción 3D de las trayectorias del caminado humano. Posteriormente se define un conjunto de parámetros cinemáticos de caminado para analizar los diferentes patrones de caminado. Finalmente se realiza una serie de experimentos con tres adultos jóvenes a los cuales se les pidió caminar bajo diferentes condiciones como en la vida real, tales como caminar subiendo una pendiente, caminar sin braceo, caminar sosteniendo una carga la frente, caminar sosteniendo una carga lateral, caminar rápido y caminar con zapato de tacón alto. Los resultados han demostrado que el patrón de caminado humano varía de acuerdo a las condiciones del caminado, siendo una de las variaciones más comunes un caminado más lento con pasos más cortos que el caminado normal. Debido a que el objetivo del trabajo es identificar y evaluar variaciones del patrón de caminado bajo diversas condiciones, solamente se consideraron tres sujetos de estudio. Sin embargo, para proporcionar resultados más precisos y normalizados el tamaño de la muestra debe incrementarse considerando diferentes edades, estaturas, sexo, peso, y condiciones de salud de los participantes. Los patrones del caminado humano son muy importantes para el diagnóstico médico y ortopédico, las evaluaciones patológicas y de envejecimiento, la rehabilitación médica, y el diseño de sistemas de rehabilitación, prótesis humanas y robots humanoides. Sin embargo, la mayoría de los trabajos de investigación reportados en la literatura se han enfocado principalmente en el análisis del patrón de caminado humano bajo condiciones normales de caminado. Estos estudios del caminado humano han dado lugar a un conocimiento limitado debido a que las condiciones del caminado en la vida real son diversas, por ejemplo caminar con una carga. Este trabajo presenta el análisis del patrón de caminado de tres adultos jóvenes bajo diversas condiciones de caminado similares a la vida real. El patrón de caminado humano varía de acuerdo a las condiciones de caminado, lo cual debe ser considerado durante en análisis, evaluación y diagnóstico del desempeño de caminado, o durante el proceso de diseño de prótesis o sistemas de rehabilitación.

Long-term results and complications related to Crurasoft® mesh repair for paraesophageal hiatal hernias.

PURPOSE: The application of mesh-reinforced hiatal closure has resulted in a significant reduction in recurrence rates in comparison with primary suture repair. However, the use of meshes has not completely extended in all the cases of large paraesophageal hiatal hernias (LPHH) due to the complications related to them. The aim of this study is to present our long-term results and complications related to Crurasoft® mesh (Bard) for the treatment of LPHH. METHODS: From January 2004 to December 2014, 536 consecutive patients underwent open or laparoscopic fundoplication for gastroesophageal reflux disease or LPHH at Ramón y Cajal University Hospital. Primary simple suture of the crura and additional reinforcement with a Crurasoft® mesh (Bard) was performed in 93 patients (17.35 %). Radiologic hiatal hernia recurrence and mesh-related complications were investigated. RESULTS: Of the 93 patients undergoing mesh repair, there were 28 male and 65 female with a mean age of 67.27 years (range 22-87 years). Laparoscopic surgery was attended in 88.2 % of the cases, and open surgery in the rest 11.8 %. Mean operative time was 167.05 min (range 90-370 min). Median postoperative stay was 4.79 days (range 1-41 days). Conversion rate was 8.53 % (7 patients). Intraoperative complications were described in 10.75 % (10 patients), but all of them, except in one case, could be managed laparoscopically. Overall postoperative complications rate was 28 %. Early postoperative complications occurred in 11 patients (12 %), respectively, for grades 2 (6 cases), 3b (1 case) and 5 (4 cases) according to the Clavien-Dindo classification. Late postoperative complications occurred in 15 patients (16 %), respectively, for grades 1 (7 cases), 2 (2 cases), 3b (5 cases) and 5 (1 case) according to the Clavien-Dindo classification. Thirty day-mortality rate was 4.3 %. Mortality rate specific associated with the mesh was 1 %. Reoperation rate was 5.4 %. After a median follow-up of 76.33 months (range 3-130 months), 8 patients (9 %) developed a recurrent hiatal hernia. Mesh was removed in three cases (3.22 %). CONCLUSIONS: In our experience, the recurrence rate in patients with a Crurasoft® (Bard) is acceptable. However, the rate of postoperative complications and mortality is excessive. The use of meshes in the hiatus keeps on being controversial due to the severe complications related to them. It would be advisable to compare our results in the non-mesh group in terms of recurrences and complications, to determine if meshes in the hiatus should be given in these patients due to its high rate of complications.

Adenoma serrado de apéndice cecal en un caso de apendicitis aguda / Serrated appendix adenoma in an acute apendicitis case

En un paciente de diecinueve años de edad intervenido por apendicitis aguda se localizó un adenoma serrado con displasia de bajo grado en la pieza quirúrgica. Dichas lesiones son infrecuentes, pero pueden ir asociadas a cáncer colorrectal y síndromes de poliposis serrada, a través de la "vía serrada de la carcinogénesis". La evidencia actualmente disponible sugiere que los pólipos serrados apendiculares pueden tener ligeras diferencias con respecto a sus análogos colorrectales. Sin embargo, se mantienen las recomendaciones para dichos pólipos, que recomiendan su extirpación completa en caso de objetivarse displasia, y la realización de colonoscopia de seguimiento

A serrated adenoma with low grade dysplasia was founded in the appendectomy specimen of a nineteen year old male intervened due to acute appendicitis. These lesions are infrequent, but might be associated with colorectal cancer and a serrated polyposis syndrome thought the "serrated pathway of carcinogenesis". Actual evidence suggests that serrated polyps found in the appendix can differ from their colorrectal analogues. However, the same recommendations are regarded, and they should be completely removed when showing dysplasia, and be followed with routinely colonoscopy

Transmission dynamics of HIV-1 subtype B in the Basque Country, Spain.

This work was aimed to study the HIV-1 subtype B epidemics in the Basque Country, Spain. 1727 HIV-1 subtype B sequences comprising protease and reverse transcriptase (PR/RT) coding regions, sampled between 2001 and 2008, were analyzed. 156 transmission clusters were detected by means of phylogenetic analyses. Most of them comprised less than 4 individuals and, in total, they included 441 patients. Six clusters comprised 10 or more patients and were further analyzed in order to study their origin and diversification. Four clusters included men who had unprotected homosexual sex (MSM), one group was formed by intravenous drug users (IDUs), and another included both IDUs and people infected through unprotected heterosexual sex (HTs). Most of these clusters originated from the mid-1980s to the mid-1990s. Only one cluster, formed by MSM, originated after 2000. The time between infections was significantly lower in MSM groups than in those containing IDUs (P-value <0.0001). Nucleoside RT and non-nucleoside RT inhibitor (NRTI and NNRTI)-resistance mutations to antiretroviral treatment were found in these six clusters except the most recent MSM group, but only the IDU clusters presented protease inhibitor (PI)-resistance mutations. The most prevalent mutations for each inhibitor class were PI L90M, NRTI T215D/Y/F, and NNRTI K103N, which were also among the most prevalent resistant variants in the whole dataset. In conclusion, while most infections occur as isolated introductions into the population, the number of infections found to be epidemiologically related within the Basque Country is significant. Public health control measures should be reinforced to prevent the further expansion of transmission clusters and resistant mutations occurring within them.

Educational impact of a clinical anatomy workshop on 1st-year orthopedic and rheumatology fellows in Mexico City.

We aim to study the educational impact of a clinical anatomy workshop in 1st-year orthopedic and rheumatology fellows. First-year rheumatology fellows (N = 17) and a convenience sample of 1st-year orthopedic fellows (N = 14) from Mexico City in the 9th month of training participated in the study. The pre- and the post- workshop tests included the same 20 questions that had to be answered by identification or demonstration of relevant anatomical items. The questions, arranged by anatomical regions, were asked in five dynamic stations. Overall, the 31 participants showed an increase of correct answers, from a median of 6 (range 1 to 12) in the pre-workshop test, to a median of 14 (range 7 to 19) in the post-workshop test. In the pre-workshop test, the correct median answers were 7 (range 2 to 12) in the orthopedic fellows and 5 (range 1 to 10) in the rheumatology fellows (p = 0.297). Corresponding scores in the post-workshop were 15 (range 10 to 19) and 12 (range 7 to 18) (p = 0.026) showing a significant difference favoring the orthopedic group. Our clinical anatomy workshop was efficacious, in the short term, as a teaching instrument for 1st-year orthopedic and rheumatology fellows. The post-workshop scores, although significantly improved in both groups, particularly in the orthopedic fellows, were still suboptimal. Further refinements of our workshop might yield better results.

Reemplazo femoral total, reporte de tres casos con revisión de la literatura / Total femoral replacement. Three case reports and literature review

Introducción: En la actualidad, la cirugía de recambio articular de cadera y rodilla es un procedimiento común en centros ortopédicos. Sin embargo, sabemos que este tipo de cirugía tiene vigencia y requiere procedimientos de revisión. Estos últimos generalmente conllevan complicaciones importantes como la pérdida de hueso que puede llegar a comprometer la estabilidad de los implantes. Métodos: Se realizaron tres revisiones de artroplastía tanto de cadera como de rodilla que han requerido el reemplazo total del fémur y de las articulaciones involucradas en el período comprendido del 2006 al 2011. El objetivo del presente trabajo es presentar la experiencia con estos implantes en cirugía de revisión de artroplastía. Resultados: El protocolo de manejo del postoperatorio fue estandarizado para todos y cada uno de los pacientes, requirieron manejo mediante desbridamientos y antibioticoterapia específica. Evidenciaron mejora significativa en el puntaje de la escala visual análoga del dolor (8-2.3 puntos p < 0.05) y funcional con la escala de valoración de WOMAC (21.6 preoperatorio a 55 puntos p < 0.05). Conclusiones: El reemplazo femoral total es un procedimiento quirúrgico de salvamento poco frecuente, demandante y complejo, que representa una alternativa ante la desarticulación de la extremidad pélvica en la etapa final de la enfermedad protésica. Se trata de una opción factible de realizar para mejorar la funcionalidad del paciente y disminuir la discapacidad residual para la realización de actividades de manera independiente.

Introduction: Currently hip and knee joint replacement were performed frequently at orthopedic centers. However, these surgeries do not last forever and thus revision procedures are required. The latter usually involve complications like bone loss that may compromise implant stability. Methods: Three hip and knee arthroplasty revisions were performed from 2006 to 2011, which warranted the total replacement of the femur and the joints involved. The purpose of this paper is to describe our experience with these implants used in arthroplasty revision surgery. Results: A standardized postoperative management protocol was used in all patients. They required debridement and specific antibiotic therapy. They had a significant improvement in the pain visual analog scale (VAS) (the score went from 8 to 2.3, p < 0.05) and in function, measured with the WOMAC score (from a preoperative score of 21.6 to 55, p < 0.05). Conclusions: Total femoral replacement is an infrequent, demanding and complex salvage surgery that represents an alternative to the disarticulation of the pelvic limb at the end stage of prosthetic disease. This is a feasible option used to improve patient functionality and decrease residual capacity for performing activities independently.

Interethnic variation of the MMP-9 microsatellite in Amerindian and Mexican Mestizo populations: considerations for genetic association studies.

We studied the interethnic variation of the MMP-9 microsatellite in the Mestizo and Amerindian populations using blood samples collected from 435 healthy unrelated individuals from the Central Valley of Mexico. DNA samples were genotyped using the -90 (CA)12-27 repeat near the MMP transcriptional start site using capillary electrophoresis. Our data were compared with those from African, Asian, and European populations (N = 729). Both Mestizo and Amerindian populations were in Hardy-Weinberg equilibrium (P ≥ 0.05). However, strong genetic heterogeneity was found within the Mestizo population (94%, P ≤ 0.0001), which exhibited the highest frequency of Amerindian, African, and European alleles. Likewise, Amerindians showed 6.7% variation among populations (P ≤ 0.0001), suggesting a genetic substructure potentially associated with linguistic affiliations. These findings were corroborated with principal component and population differentiation analyses, which showed relative proximity among the Mestizos and their historical parental populations: Asian (FST ≥ 0.05), European (FST ≥ 0.09), and African (FST ≥ 0.02). Nevertheless, important differences were found between Mestizo and Nahuas (P ≤ 0.0001), and between Mestizo and Me'Phaas (P ≤ 0.0001). These findings highlight the importance of determining local-specific patterns to establish the population variability of MMP-9 and other polymorphic markers. Validation of candidate markers is critical to identifying risk factors; however, this depends on knowledge of population genetic variation, which increases the possibility of finding true causative variants. We also show that dissimilar ethnic backgrounds might lead to spurious associations. Our study provides useful considerations for greater accuracy and robustness in future genetic association studies.

Analysis of the genotypic diversity of strains of Helicobacter pylori isolated from pediatric patients in Mexico.

Genotypic differences in Helicobacter pylori play an important role in infection. We characterized the diversity of the cagA, cagE, babA2, and vacA genes in H. pylori strains isolated from pediatric patients and the relationship between these genes and clinical disease. Additionally, we employed the Neighbor-net algorithm to predict the behavior of the genotypes of the strains isolated from patients. Of 93 patients analyzed, 32 were positive for infection. A total of 160 H. pylori strains (five isolates per positive patient) were analyzed. A total of 91% and 83% of strains possessed the cagA and cagE genes, respectively. For the vacA gene, 84% of strains possessed the s1 allele, 15% the s2 allele, 81% the m1 allele and 13.8% the m2 allele. The babA2 gene was present in 79% of strains. Infection with H. pylori strains with the vacA (s1m1) genotype was associated with risk of esophagitis and gastritis (p=0.0001). The combination of cagA and vacA (s1m1) was significantly associated with abdominal pain (p=0.002); however, EPIYA type was not significantly associated with abdominal pain. A total of 16 different genotypes were identified; the most common genotype was vacAs1m1cagA+cagE+babA2+ (47.5%). A total of 84% of pediatric patients were infected by at least two and up to five different genotypes. The network recovered two genotype groups (A: strains with vacAs1 and B: strains with vacAs2). The presence of multiple paths in the network suggests that reticulate events, such as recombination or reinfection, have contributed to the observed genotypic diversity.

Selection on outlier loci and their association with adaptive phenotypes in Littorina saxatilis contact zones.

A fundamental issue in speciation research is to evaluate phenotypic variation and the genomics driving the evolution of reproductive isolation between sister taxa. Above all, hybrid zones are excellent study systems for researchers to examine the association of genetic differentiation, phenotypic variation and the strength of selection. We investigated two contact zones in the marine gastropod Littorina saxatilis and utilized landmark-based geometric morphometric analysis together with amplified fragment length polymorphism (AFLP) markers to assess phenotypic and genomic divergence between ecotypes under divergent selection. From genetic markers, we calculated the cline width, linkage disequilibrium and the average effective selection on a locus. Additionally, we conducted an association analysis linking the outlier loci and phenotypic variation between ecotypes and show that a proportion of outlier loci are associated with key adaptive phenotypic traits.

[Total femoral replacement. Three case reports and literature review]. / Reemplazo femoral total, reporte de tres casos con revisión de la literatura.

INTRODUCTION: Currently hip and knee joint replacement were performed frequently at orthopedic centers. However, these surgeries do not last forever and thus revision procedures are required. The latter usually involve complications like bone loss that may compromise implant stability. METHODS: Three hip and knee arthroplasty revisions were performed from 2006 to 2011, which warranted the total replacement of the femur and the joints involved. The purpose of this paper is to describe our experience with these implants used in arthroplasty revision surgery. RESULTS: A standardized postoperative management protocol was used in all patients. They required debridement and specific antibiotic therapy. They had a significant improvement in the pain visual analog scale (VAS) (the score went from 8 to 2.3, p < 0.05) and in function, measured with the WOMAC score (from a preoperative score of 21.6 to 55, p < 0.05). CONCLUSIONS: Total femoral replacement is an infrequent, demanding and complex salvage surgery that represents an alternative to the disarticulation of the pelvic limb at the end stage of prosthetic disease. This is a feasible option used to improve patient functionality and decrease residual capacity for performing activities independently.

INTRODUCCIÓN: En la actualidad, la cirugía de recambio articular de cadera y rodilla es un procedimiento común en centros ortopédicos. Sin embargo, sabemos que este tipo de cirugía tiene vigencia y requiere procedimientos de revisión. Estos últimos generalmente conllevan complicaciones importantes como la pérdida de hueso que puede llegar a comprometer la estabilidad de los implantes. MÉTODOS: Se realizaron tres revisiones de artroplastía tanto de cadera como de rodilla que han requerido el reemplazo total del fémur y de las articulaciones involucradas en el período comprendido del 2006 al 2011. El objetivo del presente trabajo es presentar la experiencia con estos implantes en cirugía de revisión de artroplastía. RESULTADOS: El protocolo de manejo del postoperatorio fue estandarizado para todos y cada uno de los pacientes, requirieron manejo mediante desbridamientos y antibioticoterapia específica. Evidenciaron mejora significativa en el puntaje de la escala visual análoga del dolor (8-2.3 puntos p < 0.05) y funcional con la escala de valoración de WOMAC (21.6 preoperatorio a 55 puntos p < 0.05). CONCLUSIONES: El reemplazo femoral total es un procedimiento quirúrgico de salvamento poco frecuente, demandante y complejo, que representa una alternativa ante la desarticulación de la extremidad pélvica en la etapa final de la enfermedad protésica. Se trata de una opción factible de realizar para mejorar la funcionalidad del paciente y disminuir la discapacidad residual para la realización de actividades de manera independiente.

¿Podría englobarse la fibromatosis agresiva dentro del espectro de los tumores del estroma gastrointestinal? / Could aggressive fibromatosis be considered whitin the spectrum of gstrointestinal stromal tumors?

Los tumores desmoides aparecen como resultado de la proliferación fibroblástica, sin signos histológicos de malignidad pero localmente muy agresivos. Se han descrito casos de fibromatosis tras extirpación de GIST. Presentamos el caso de un GIST gástrico operado, que a los 18 meses se realiza laparotomía exploradora por sospecha de recurrencia y tras hallazgos histológicos definitivos, se diagnostica de fibromatosis intra-abdominal agresiva. Se discute la valoración clínico-oncológica de la fibromatosis como forma de recurrencia local del GIST

Desmoid tumors appear as a result of fibroblastic proliferation without histological signs of malignancy but locally aggressive. Fibromatosis have been described after removing a gastrointestinal stromal tumor (GIST). We present a case of a resected gastric GIST and eigthteen months after surgery, a exploratory laparotomy was performed suspecting recurrence and after definitive histological findings, the diagnosis was aggressive intra-abdominal fibromatosis. Clinical-oncological assessment of fibromatosis is discussed as a form of GIST local recurrence