Exploring the effect of sedentary behavior on increased adiposity in middle-aged adults.

BACKGROUND: Sedentary behavior is linked to excess fat mass; however, this association may be inconclusive due to potential measurement errors in self-reported sedentary behavior. OBJECTIVE: To assess the association between changes in sedentary behavior and fat mass in a Cohort of Health Workers (HWCS) from 2004 to 2010. METHODS: A total of 1,285 adults participating in the Cohort of Health Workers were evaluated in 2004 and 2010. Fat mass (kg) was measured by dual X-ray absorptiometry. A self-administered questionnaire was used to estimate the sedentary behavior. Sedentary behavior was also estimated using accelerometry in a sample of 142 health workers. Accelerometry data were used to correct self-reported sedentary behavior using a generalized linear model, which included values for sleeping time, age, sex, sedentary behavior, glucose, and triglycerides. Concordance between both methods was assessed using a kappa and Bland-Altman analysis. Once sedentary behavior was corrected, the values were used to evaluate the association between changes in sedentary behavior and body fat mass using a fixed effect model in the cohort, adjusting for confounders. RESULTS: Self-reported sedentary behavior was 2.8 ± 1.8 and 2.3 ± 1.6 h/day, and body fat mass was 24.9 ± 8.1 and 26.8 ± 8.5 kg in 2004 and 2010, respectively. After applying the correction model, the self-reported sedentary behavior was 7.6 ± 1.2 and 7.5 ± 1.2 h/day in 2004 and 2010, respectively. For every hour increase in corrected sedentary behavior, there was an observed increase of 0.847 (p > 0.001) kg in body fat mass during the 6.8 years in the Cohort of Health Workers from 2004 to 2010. Conversely, non-corrected self-reported sedentary behavior was associated with a non-significant reduction of 0.097 kg (p = 0.228) for every hour of sedentary behavior. CONCLUSIONS: Increased sedentary behavior was associated with increased body fat mass when corrected self-reported sedentary behavior was used. Implementing public health strategies to reduce sedentary behavior is imperative.

Evaluation and economic analysis of fermented fish viscera silage in diets for tambaqui (Colossoma macropomum) and its effects on the physical quality of pellets, growth performance, health parameters.

The production of silage using fish viscera can be carried out with straightforward methods and permits the exploitation of nutrients that are usually discarded. This process fosters the concept of circular aquaculture. The aim of this study was to evaluate the inclusion of increasing levels of fish viscera silage (VS) on the physical quality of the feed pellets and their effects on their growth performance, health parameters and on economic indices when the experimental extruded feed was offered to tambaqui. A fermented fish VS produced in-house was included in increasing levels on a wet-basis in the formulation of five experimental diets (VS 0%, VS 5%; VS 10%; VS 15% and VS 20%). Juvenile tambaqui (~22.6 g) were stocked in fibreglass tanks of 700 L (n = 4; 21 fish per tank) with a recirculation system and the five experimental diets were attributed in a completely randomized design. The fish were fed with the experimental diets (to apparent satiation) for 13 weeks. At the end of the trial, no significant differences were observed for production performance. Fish fed with the highest inclusion level of VS presented the highest concentration of plasma cholesterol, but this was still within acceptable values for this species. The inclusion of fish VS in diets for juvenile tambaqui reduced the activity of the plasma ALT enzyme, confirming normal liver function. Extruded feed containing fish VS had a production cost of US$ 0.95 per kg, which does not significantly impact the economic indices. Up to 20% of fish VS can be included in the extruded feed formulation for juvenile tambaqui without impairing growth performance or affecting health parameters.

Asymptotic behavior of mean fixation times in the Moran process with frequency-independent fitnesses.

We derive asymptotic formulae in the limit when population size N tends to infinity for mean fixation times (conditional and unconditional) in a population with two types of individuals, A and B, governed by the Moran process. We consider only the case in which the fitness of the two types do not depend on the population frequencies. Our results start with the important cases in which the initial condition is a single individual of any type, but we also consider the initial condition of a fraction [Formula: see text] of A individuals, where x is kept fixed and the total population size tends to infinity. In the cases covered by Antal and Scheuring (Bull Math Biol 68(8):1923-1944, 2006), i.e. conditional fixation times for a single individual of any type, it will turn out that our formulae are much more accurate than the ones they found. As quoted, our results include other situations not treated by them. An interesting and counterintuitive consequence of our results on mean conditional fixation times is the following. Suppose that a population consists initially of fitter individuals at fraction x and less fit individuals at a fraction [Formula: see text]. If population size N is large enough, then in the average the fixation of the less fit individuals is faster (provided it occurs) than fixation of the fitter individuals, even if x is close to 1, i.e. fitter individuals are the majority.

Systematic literature review of instruments that measure the healthfulness of food and beverages sold in informal food outlets.

BACKGROUND: Informal food outlets, defined as vendors who rarely have access to water and toilets, much less shelter and electricity, are a common component of the food environment, particularly in many non-Western countries. The purpose of this study was to review available instruments that measure the quality and particularly the healthfulness of food and beverages sold within informal food outlets. METHODS: PubMed, LILACS, Web of Science, and Scopus databases were used. Articles were included if they reported instruments that measured the availability or type of healthy and unhealthy foods and beverages by informal food outlets, were written in English or Spanish, and published between January 1, 2010, and July 31, 2020. Two trained researchers reviewed the title, abstract and full text of selected articles; discrepancies were solved by two independent researchers. In addition, the list of references for selected articles was reviewed for any additional articles of relevance. The quality of published articles and documents was evaluated using JBI Critical appraisal checklist for analytical cross-sectional studies. RESULTS: We identified 1078 articles of which 14 were included after applying the selection criteria. Three additional articles were considered after reviewing the references from the selected articles. From the final 17 articles, 13 measurement tools were identified. Most of the instruments were used in low- and middle-income countries (LMIC). Products were classified as healthy/unhealthy or produce/non-produce or processed/unprocessed based on availability and type. Six studies reported psychometric tests, whereas one was tested within the informal food sector. CONCLUSIONS: Few instruments can measure the healthfulness of food and beverages sold in informal food outlets, of which the most valid and reliable have been used to measure formal food outlets as well. Therefore, it is necessary to develop an instrument that manages to measure, specifically, the elements available within an informal one. These actions are extremely important to better understand the food environment that is a central contributor to poor diets that are increasingly associated with the obesity and Non-communicable disease (NCD) pandemic.

Recombinant Fasciola hepatica Fatty Acid Binding Protein as a Novel Anti-Inflammatory Biotherapeutic Drug in an Acute Gram-Negative Nonhuman Primate Sepsis Model.

Due to their phylogenetic proximity to humans, nonhuman primates (NHPs) are considered an adequate choice for a basic and preclinical model of sepsis. Gram-negative bacteria are the primary causative of sepsis. During infection, bacteria continuously release the potent toxin lipopolysaccharide (LPS) into the bloodstream, which triggers an uncontrolled systemic inflammatory response leading to death. Our previous research has demonstrated in vitro and in vivo using a mouse model of septic shock that Fh15, a recombinant variant of the Fasciola hepatica fatty acid binding protein, acts as an antagonist of Toll-like receptor 4 (TLR4) suppressing the LPS-induced proinflammatory cytokine storm. The present communication is a proof-of concept study aimed to demonstrate that a low-dose of Fh15 suppresses the cytokine storm and other inflammatory markers during the early phase of sepsis induced in rhesus macaques by intravenous (i.v.) infusion with lethal doses of live Escherichia coli. Fh15 was administered as an isotonic infusion 30 min prior to the bacterial infusion. Among the novel findings reported in this communication, Fh15 (i) significantly prevented bacteremia, suppressed LPS levels in plasma, and the production of C-reactive protein and procalcitonin, which are key signatures of inflammation and bacterial infection, respectively; (ii) reduced the production of proinflammatory cytokines; and (iii) increased innate immune cell populations in blood, which suggests a role in promoting a prolonged steady state in rhesus macaques even in the presence of inflammatory stimuli. This report is the first to demonstrate that a F. hepatica-derived molecule possesses potential as an anti-inflammatory drug against sepsis in an NHP model. IMPORTANCE Sepsis caused by Gram-negative bacteria affects 1.7 million adults annually in the United States and is one of the most important causes of death at intensive care units. Although the effective use of antibiotics has resulted in improved prognosis of sepsis, the pathological and deathly effects have been attributed to the persistent inflammatory cascade. There is a present need to develop anti-inflammatory agents that can suppress or neutralize the inflammatory responses and prevent the lethal consequences of sepsis. We demonstrated here that a small molecule of 14.5 kDa can suppress the bacteremia, endotoxemia, and many other inflammatory markers in an acute Gram-negative sepsis rhesus macaque model. These results reinforce the notion that Fh15 constitutes an excellent candidate for drug development against sepsis.

Robotic rectal surgery: Outcomes of the first 102 totally robotic cases handled using the single-docking technique in a reference institution.

BACKGROUND AND OBJECTIVE: Rectal cancer is often surgically treated, but it is still associated with morbidity rates. Minimally invasive techniques are increasingly being used to reduce complications, and the use of such techniques can be found in the literature. This study aims to report our experience in a reference oncology center. METHODS: A retrospective cohort study was performed on a prospective database of patients who underwent robotic surgery for rectal cancer using the single-docking technique from September 2014 to April 2018. Clinical and surgical variables, as well as morbidity and mortality rates, were analyzed. RESULTS: One hundred and two patients underwent robotic surgery. Intraoperative complications occurred in six patients (4.9%), and postoperative complications in 24 patients (23.5%), of which anastomotic fistula represented 3.9%. The conversion rate was 1.96%. Two cases (1.9%) faced death within 30 days. The median length of hospitalization was 3 days. The median number of lymph nodes dissected was 15. Clinical and surgical data were correlated with postoperative complications, and no statistically significant differences were found. CONCLUSION: Robotic surgery is a safe and feasible approach to manage rectal cancer. The method presents satisfactory results with regard to the rate of operative complications, conversion rate, oncologic outcomes, and length of hospitalization.

Overview and perspectives about the robotic surgical certification process in Brazil: the new statement and a national web-survey.

OBJECTIVE: to appraise the general profile of the Brazilian robotic surgeon and the acknowledgment of the new certification process for robotic surgery upon the Associação Médica Brasileira (AMB - Brazilian Medical Association) statement. According to the AMB statement, medical societies and proctors have to achieve leading roles in training and certification of surgeons, acting in partnership with industry. METHODS: a national web-based survey was promoted by the Colégio Brasileiro de Cirurgiões (CBC - Brazilian College of Surgeons) among their members. RESULTS: the 294 answers were split into two groups: 133 (45.3%) who had robotic console certification, and 161 (54.8%) who did not have it. The overall median age was 46, but the non-robotic group presented more surgeons with at least 30 years of experience than to the robotic group (32.3% versus 23.3%, p=0.033). Surgeons with robotic certification more frequently work in a city with at least one million inhabitants than surgeons who were not certified (85.7 versus 63.4%, p<0.001). The majority of surgeons in both groups have similar positioning for all main points of the statement. However, the agreement proportions for the preceptors responsibility during the procedures were higher among non-robotic surgeons that expected the preceptor to assume co-responsibility for the procedure (85% versus 60.9%, p<0.001), and intervene during the procedure as much as necessary (97.5% versus 91.7%, p=0.033). CONCLUSION: the overall agreement of the answers to the AMB statement seems to be a promising pathway to increase the participation of the medical entities into the robotic certification in Brazil.

Predicting the evolution of the COVID-19 epidemic with the A-SIR model: Lombardy, Italy and São Paulo state, Brazil.

The presence of a large number of infected individuals with few or no symptoms is an important epidemiological difficulty and the main mathematical feature of COVID-19. The A-SIR model, i.e. a SIR (Susceptible-Infected-Removed) model with a compartment for infected individuals with no symptoms or few symptoms was proposed by Gaeta (2020). In this paper we investigate a slightly generalized version of the same model and propose a scheme for fitting the parameters of the model to real data using the time series only of the deceased individuals. The scheme is applied to the concrete cases of Lombardy, Italy and São Paulo state, Brazil, showing different aspects of the epidemic. In both cases we see strong evidence that the adoption of social distancing measures contributed to a slower increase in the number of deceased individuals when compared to the baseline of no reduction in the infection rate. Both for Lombardy and São Paulo we show that we may have good fits to the data up to the present, but with very large differences in the future behavior. The reasons behind such disparate outcomes are the uncertainty on the value of a key parameter, the probability that an infected individual is fully symptomatic, and on the intensity of the social distancing measures adopted. This conclusion enforces the necessity of trying to determine the real number of infected individuals in a population, symptomatic or asymptomatic.

Fixation probabilities for the Moran process with three or more strategies: general and coupling results.

We study fixation probabilities for the Moran stochastic process for the evolution of a population with three or more types of individuals and frequency-dependent fitnesses. Contrary to the case of populations with two types of individuals, in which fixation probabilities may be calculated by an exact formula, here we must solve a large system of linear equations. We first show that this system always has a unique solution. Other results are upper and lower bounds for the fixation probabilities obtained by coupling the Moran process with three strategies with birth-death processes with only two strategies. We also apply our bounds to the problem of evolution of cooperation in a population with three types of individuals already studied in a deterministic setting by Núñez Rodríguez and Neves (J Math Biol 73:1665-1690, 2016). We argue that cooperators will be fixated in the population with probability arbitrarily close to 1 for a large region of initial conditions and large enough population sizes.

Overview and perspectives about the robotic surgical certification process in Brazil: the new statement and a national web-survey / Visão geral e perspectivas sobre o processo de certificação em cirurgia robótica no Brasil: o novo regimento e uma pesquisa nacional online

ABSTRACT Objective: to appraise the general profile of the Brazilian robotic surgeon and the acknowledgment of the new certification process for robotic surgery upon the Associação Médica Brasileira (AMB - Brazilian Medical Association) statement. According to the AMB statement, medical societies and proctors have to achieve leading roles in training and certification of surgeons, acting in partnership with industry. Methods: a national web-based survey was promoted by the Colégio Brasileiro de Cirurgiões (CBC - Brazilian College of Surgeons) among their members. Results: the 294 answers were split into two groups: 133 (45.3%) who had robotic console certification, and 161 (54.8%) who did not have it. The overall median age was 46, but the non-robotic group presented more surgeons with at least 30 years of experience than to the robotic group (32.3% versus 23.3%, p=0.033). Surgeons with robotic certification more frequently work in a city with at least one million inhabitants than surgeons who were not certified (85.7 versus 63.4%, p<0.001). The majority of surgeons in both groups have similar positioning for all main points of the statement. However, the agreement proportions for the preceptors responsibility during the procedures were higher among non-robotic surgeons that expected the preceptor to assume co-responsibility for the procedure (85% versus 60.9%, p<0.001), and intervene during the procedure as much as necessary (97.5% versus 91.7%, p=0.033). Conclusion: the overall agreement of the answers to the AMB statement seems to be a promising pathway to increase the participation of the medical entities into the robotic certification in Brazil.

RESUMO Objetivo: avaliar o perfil do cirurgião robótico brasileiro e seu reconhecimento sobre o novo processo de certificação para cirurgia robótica que consta na declaração da Associação Médica Brasileira (AMB). De acordo com a declaração da AMB, as sociedades médicas e os preceptores devem alcançar papéis de liderança no treinamento e certificação de cirurgiões, atuando em parceria com a indústria. Métodos: uma pesquisa nacional pela Internet foi promovida pelo Colégio Brasileiro de Cirurgiões com seus membros. Resultados: entre as 294 respostas, os cirurgiões foram divididas em dois grupos: 133 (45,3%) que possuíam certificação de console robótico e 161 (54,8%) que não possuíam. A média geral de idade foi de 46 anos, mas o grupo não robótico teve mais cirurgiões com pelo menos 30 anos de experiência (32,3% versus 23,3%, p = 0,033). Cirurgiões com certificação robótica trabalhavam mais frequentemente em cidades mais populosas, com pelo menos um milhão de habitantes (85,7 versus 63,4%, p <0,001). A maioria dos cirurgiões de ambos os grupos tem posicionamento semelhante para todos os pontos principais da declaração. No entanto, as proporções de concordância para a responsabilidade do preceptor durante os procedimentos foram maiores entre os cirurgiões não robóticos que esperavam que o preceptor assumisse corresponsabilidade pelo procedimento (85% versus 60,9%, p <0,001), e que intervenha , tanto quanto necessário (97,5% versus 91,7%, p = 0,033). Conclusão: a aceitação por parte da maioria dos profissionais em relação à declaraçãoda AMB parece ser caminho promissor para aumentar a participação das entidades médicas na certificação robótica no Brasil.

Fixation probabilities for the Moran process in evolutionary games with two strategies: graph shapes and large population asymptotics.

This paper is based on the complete classification of evolutionary scenarios for the Moran process with two strategies given by Taylor et al. (Bull Math Biol 66(6):1621-1644, 2004. https://doi.org/10.1016/j.bulm.2004.03.004 ). Their classification is based on whether each strategy is a Nash equilibrium and whether the fixation probability for a single individual of each strategy is larger or smaller than its value for neutral evolution. We improve on this analysis by showing that each evolutionary scenario is characterized by a definite graph shape for the fixation probability function. A second class of results deals with the behavior of the fixation probability when the population size tends to infinity. We develop asymptotic formulae that approximate the fixation probability in this limit and conclude that some of the evolutionary scenarios cannot exist when the population size is large.

Malformación vascular capilar y venosa en la mano. Reporte de caso de una extraña patología quirúrgica / Vascular capillary and venous malformation in the hand. Case report of a strange surgical pathology

Resumen Introducción: Las anomalías vasculares representan un amplio panorama de distintas lesiones donde los tumores son los más frecuentes. Las malformaciones vasculares suelen presentarse en etapas tardías de la vida secundarias al lento crecimiento y a los síntomas que padecen los pacientes. Debe de darse un manejo multidisciplinario donde el diagnóstico es la piedra angular. Los casos de malformaciones venosas o linfáticas suelen tratarse mediante la resección de la malformación en su totalidad. Presentación del caso clínico: Varón de 35 años de edad quién presenta aumento de volumen y dolor de 3 meses de evolución en la mano derecha. A la exploración física se observa una masa en la región tenar de dicha mano, con bordes bien definidos de aproximadamente 3 × 3 cm, no móvil, adherida a planos profundos, dolorosa a palpación, con hiperestesias en trayecto del nervio mediano. Se realizaron ultrasonido Doppler y resonancia magnética, los cuales sugirieron una lesión vascular. Se realizó exploración quirúrgica y se observó una lesión vascular adherida a las estructuras nerviosa y tendinosa, las cuales se liberaron y se extrajo la tumoración. Se envió la pieza quirúrgica a patología, que reportó hemangioma capilar y venoso. Conclusiones: Las malformaciones vasculares mixtas (venoso y capilar) en la mano son una entidad poco frecuente que requiere de un manejo quirúrgico preciso. Estas lesiones generan síntomas asociados al aumento de volumen, entre los que destacan: dolor, disminución del rango de movimientos. El tratamiento quirúrgico se asocia a una mejoría de los síntomas.

Abstract Introduction: Vascular anomalies in the hand represent a rare disease that needs an accurate diagnosis and prompt surgical treatment. One of the uncommon anomalies is the mixed vascular one. The diagnosis of these malformations is clinical but radiological studies such as magnetic resonance and Doppler ultrasound are mandatory. Once the diagnosis is made, surgery is the next and final step. Recurrence is rare when the entire tumor is resected. Clinical Case Study: A 35-year-old male presented with an increase in volume and pain of three months of evolution in the right hand. On physical examination, a mass in the righthand thenar region was observed, with well-defined edges of approximately 3 x 3 cm, not mobile, adhered to deep planes, painful to palpation, with hyperesthesias in the median nerve pathway. A magnetic resonance and a Doppler ultrasound were applied showing a well-circumscribed tumor. The patient underwent surgery and the whole vascular malformation was removed with no damage of neighbor structures. Pathology reported a venous and capillary hemangioma. Conclusions: Mixed vascular malformations in the hand are uncommon pathologies that require a correct diagnosis and a prompt surgical resolution. The most frequent symptoms associated with these tumors are: tenderness, pain and limitation in the movement of the hand. Surgical treatment is always recommended.

Reconstrucción auricular traumática con colgajo retroauricular. Una alternativa vigente y reproducible para los médicos residentes en formación / Traumatic auricular reconstruction with a retroauricular flap. A current and reproducible alternative for resident doctors in training

Resumen Introducción La reconstrucción auricular traumática es un reto para el cirujano plástico. Su objetivo es reproducir y recrear la forma y topografía de la región auricular, haciendo que los estigmas propios de la reconstrucción sean mínimos. Caso clínico Se presenta el caso de un paciente varón de 5 años de edad, con lesión por mordedura de perro en la oreja derecha, y lesión corto-contusa en pabellón auricular con pérdida de cobertura cutánea, pérdida parcial de cartílago auricular y exposición cartilaginosa a nivel de hélix y porción retroauricular. Se realizó reconstrucción auricular mediante reparación auricular y colgajo retroauricular. En un segundo tiempo quirúrgico, se realizó sección de la base del colgajo, y se logró un adecuado contorno auricular, así como cobertura cutánea definitiva Conclusiones Las lesiones auriculares, por su situación anatómica, son frecuentes en la práctica profesional de un cirujano plástico y reconstructivo. Existen múltiples técnicas quirúrgicas para la reconstrucción de defectos auriculares, sin embargo, el colgajo retroauricular ofrece una técnica sencilla y versátil.

Abstract Introduction Traumatic auricular reconstruction is a challenge for the plastic surgeon. The purpose of this reconstruction is to reproduce and recreate the shape and topography of the auricular region, diminishing the typical stigmas of a reconstruction. Clinical case The case of a 5-year-old male patient with right bite of a dog in a right ear presenting a short-contusional lesion in the auricular hall with loss of cutaneous cover, partial loss of atrial cartilage and cartilage exposure At the level of helix and retroauricular portion. Auricular reconstruction is performed by atrial repair and retroauricular flap. In a second surgical time, a section of the base of the flap is performed, achieving a suitable atrial contour and definitive skin coverage. Conclusions Auricular injuries, due to their anatomical situation, are frequent in the professional practice of a plastic and reconstructive surgeon. There are multiple surgical techniques for the reconstruction of atrial defects, however, the retroauricular flap offers a simple and versatile technique.

Enfermedad pulmonar obstructiva crónica en el primer nivel de atención: magnitud y características de los casos y de la atención / Chronic obstructive pulmonary disease in the first level of care: magnitude and characteristics of the cases and care

INTRODUCCIÓN Las enfermedades respiratorias crónicas tienen gran relevancia como problema de salud a nivel mundial por su carga de enfermedad y muerte, que es cada vez mayor. En particular, es cada vez más importante dentro de los problemas respiratorios. En Argentina, más del 13% de las muertes totales se deben a asma y enfermedad pulmonar obstructiva crónica (EPOC). OBJETIVOS Conocer las condiciones de los servicios de salud del primer nivel para la atención de EPOC y la carga de atención. OBJETIVOS Conocer las condiciones de los servicios de salud del primer nivel para la atención de EPOC y la carga de atención. MÉTODOS El estudio relevó información de 31 servicios de salud (sin atención de especialista en Neumonología) de 3 provincias. Para caracterizar las condiciones de atención de EPOC, se analizaron los siguientes aspectos, vinculados al funcionamiento y la disponibilidad de insumos y equipos: personal de salud y referencia, equipamiento, tratamiento y medicación, información, educación y comunicación (IEC) y atención de casos de EPOC. RESULTADOS Se encontraron falencias en todos los aspectos analizados. Se hallaron niveles bajos en capacitación del recurso humano en espirometría y atención de EPOC (6,5% espirometría y 25% atención). Uno de los 31 servicios contaba con espirómetro, y la mayoría tenía medicación de rescate (93,5% con broncodilatadores de acción corta y 87,1% de corticoides orales o inyectables), pero no disponían de medicación de control para estadios avanzados. El 12,9% de los servicios contaba con material de difusión sobre EPOC, y un 22,6% había realizado actividades de IEC al respecto. Un déficit similar se observó con las actividades de tabaquismo; 9,7% contaba con medicación, 29,0% tenía recursos para el tratamiento, 19,4% disponía de material de difusión y 16,1% indicó que realizaba actividades de IEC. La atención de casos de EPOC es baja; representa el 3,9% de la demanda por problemas respiratorios. DISCUSIÓN Es esencial conocer y solucionar los déficits en los establecimientos del primer nivel de atención para implementar las acciones de control de EPOC, que resultan necesarias para aumentar la cobertura.

Characterization of topoisomerase II α and minichromosome maintenance protein 2 expression in anal carcinoma.

The present study aimed to ascertain the significance of topoisomerase II α (TOP2A) and minichromosome maintenance protein (MCM) 2 expression in anal carcinoma. A total of 75 anal lesions were retrieved from the files of the Department of Pathology of Barretos Cancer Hospital (Barretos, Brazil) in order to verify the human papillomavirus (HPV) statuses of these lesions and characterize the immunohistochemical expression levels of TOP2A and MCM2 in anal carcinoma, as these are important markers for cervical HPV-induced lesions; their expression was also compared with respect to p16 and Ki-67. The vast majority of the cases tested positive for HPV16 (84%); 1 case tested positive for both HPV16 and HPV18. Positive HPV16 status was more frequent in early stages than in advanced stages (P=0.008). Positive immunohistochemical reactivity for MCM2 and TOP2A protein was observed in 71.6 and 100% of cases, respectively. Positive reactivity for p16 was significantly associated (P=0.001) with histological grade, and was more commonly expressed in squamous cell carcinoma than adenocarcinomas. HPV16 was strongly associated with positive p16 protein expression (76.6%). However, the high expression of Ki-67 combined with the high expression of p16 was predominantly observed in Stage III-IV cases. MCM2, TOP2A, p16 and Ki-67 exhibited intense positive staining in the anal lesions, indicating that these markers were significantly and constantly expressed in anal carcinoma.

Evolution of cooperation in a particular case of the infinitely repeated prisoner's dilemma with three strategies.

We study a population of individuals playing the infinitely repeated prisoner's dilemma under replicator dynamics. The population consists of three kinds of individuals adopting the following reactive strategies: ALLD (individuals which always defect), ATFT (almost tit-for-tat: individuals which almost always repeat the opponent's last move) and G (generous individuals, which always cooperate when the opponent cooperated in the last move and have a positive probability q of cooperating when their opponent has defected). Our aim is studying in a mathematically rigorous fashion the dynamics of a simplified version for the computer experiment in Nowak and Sigmund (Nature 355:250-253, 1992) involving 100 reactive strategies. We see that as the generosity degree of the G individuals varies, equilibria (rest points) of the dynamics appear or disappear, and the dynamics changes accordingly. Not only we prove that the results of the experiment are true in our simplified version, but we also have complete control on the existence or non-existence of the equilbria for the dynamics for all possible values of the parameters, given that ATFT individuals are close enough to TFT. For most values of the parameters the dynamics can be completely determined.

Video-assisted thoracoscopic surgery in swine: an animal model for thoracoscopic lobectomy training.

OBJECTIVES: Minimally invasive thoracic procedures have been increasingly used; however, only a small number of lobectomies are performed by videothoracoscopy, showing the need for training on this technique. The objective of this study is to demonstrate the technique of lobectomy using videothoracoscopy in swine, highlighting the steps to be taken during its use in surgical experimentation. METHODS: During the advanced course on video-assisted and thoracoscopic procedures carried out at IRCAD Latin America, Barretos, Brazil, 40 swine were used for the hands-on course on video-assisted upper left lobectomy. Monopulmonary ventilation was performed by blocking the left main bronchus. Surgical procedures were performed using three ports and the anterior dissection technique (fissureless approach). The pulmonary hilar structures were dissected using conventional open surgery and video-assisted surgical tools. The first structure treated in the approach of the hilar structures was the upper lobe vein, followed by the bronchus and the branches of the pulmonary artery. RESULTS: The mean time required to anaesthetize the animals was 3 h. Intraoperative hypoventilation was observed in 26 animals (65%) and 4 (10%) of them had a poor outcome and died in the last third part of the surgery. Eight (20%) animals had bradycardia, and six responded to the use of atropine. In two (5%), it was not possible to revert the bradycardia and the animals died at the end of the procedures. The surgical procedures had a mean duration of 3 h and the total time of anaesthesia was about 6 h. DISCUSSION: Swine have been frequently used for hands-on training in surgery but there are no reports in the literature describing the anatomical, anaesthetic and technical peculiarities that must be observed during videothoracoscopic lobectomy training in swine. Video-assisted thoracoscopic surgery lobectomy using swine is an adequate method to train thoracic surgeons. For surgeons to make the best use of minimally invasive technique training, it is essential that issues related to the anatomy, anaesthesia, monopulmonary ventilation and surgical technique described in this study are taken into account.

Extremely rare interbreeding events can explain neanderthal DNA in living humans.

Considering the recent experimental discovery of Green et al that present-day non-Africans have 1 to [Formula: see text] of their nuclear DNA of Neanderthal origin, we propose here a model which is able to quantify the genetic interbreeding between two subpopulations with equal fitness, living in the same geographic region. The model consists of a solvable system of deterministic ordinary differential equations containing as a stochastic ingredient a realization of the neutral Wright-Fisher process. By simulating the stochastic part of the model we are able to apply it to the interbreeding of the African ancestors of Eurasians and Middle Eastern Neanderthal subpopulations and estimate the only parameter of the model, which is the number of individuals per generation exchanged between subpopulations. Our results indicate that the amount of Neanderthal DNA in living non-Africans can be explained with maximum probability by the exchange of a single pair of individuals between the subpopulations at each 77 generations, but larger exchange frequencies are also allowed with sizeable probability. The results are compatible with a long coexistence time of 130,000 years, a total interbreeding population of order [Formula: see text] individuals, and with all living humans being descendants of Africans both for mitochondrial DNA and Y chromosome.

Laparoscopic mobilization for resection of the transverse colon for cancer: a simple, reproducible method.

Laparoscopic resection for colorectal cancer by appropriately skilled surgeons is now accepted as safe and oncologically sound. Much of the contemporary debate in this area is regarding appropriate training of surgeons, as there is a steep learning curve. Arguably, the most difficult aspect of laparoscopic colon resection is mobilization of the transverse colon, with division of the middle colic artery. Mobilizing the transverse colon is necessary for many colonic resections, including "introductory" procedures. Our department has a consistent, sequential method for mobilization of the transverse colon with proximal isolation and ligation of the middle colic artery as indicated. This involves using the head, or distal body, of the pancreas as a landmark, for right-sided and left-sided resections, respectively. We believe that this particular methodology is easy to learn and surgically efficient. We also discuss some particular intraoperative problems and scenarios, with suggested solutions.

Detailed analysis of an Eigen quasispecies model in a periodically moving sharp-peak landscape.

The Eigen quasispecies model in a periodically moving sharp-peak landscape considered in previous seminal works [M. Nilsson and N. Snoad, Phys. Rev. Lett. 84, 191 (2000)] and [C. Ronnewinkel, in, edited by L. Kallel, B. Naudts, and A. Rogers (Springer-Verlag, Heidelberg, 2001)] is analyzed in greater detail. We show here, through a more rigorous analysis, that results in those papers are qualitatively correct. In particular, we obtain a phase diagram for the existence of a quasispecies with the same shape as in the above cited paper by C. Ronnewinkel, with upper and lower thresholds for the mutation rate between which a quasispecies may survive. A difference is that the upper value is larger and the lower value is smaller than the previously reported ones, so that the range for quasispecies existence is always larger than thought before. The quantitative information provided might also be important in understanding genetic variability in virus populations and has possible applications in antiviral therapies. The results in the quoted papers were obtained by studying the populations only at some few genomes. As we will show, this amounts to diagonalizing a 3×3 matrix. Our work is based instead in a different division of the population allowing a finer control of the populations at various relevant genetic sequences. The existence of a quasispecies will be related to Perron-Frobenius eigenvalues. Although huge matrices of sizes 2(ℓ), where ℓ is the genome length, may seem necessary at a first look, we show that such large sizes are not necessary and easily obtain numerical and analytical results for their eigenvalues.