EPDR1 up-regulation in human colorectal cancer is related to staging and favours cell proliferation and invasiveness.

The finding of novel molecular markers for prediction or prognosis of invasiveness in colorectal cancer (CRC) constitutes an appealing challenge. Here we show the up-regulation of EPDR1 in a prospective cohort of 101 CRC patients, in a cDNA array of 43 patients and in in silico analyses. EPDR1 encodes a protein related to ependymins, a family of glycoproteins involved in intercellular contacts. A thorough statistical model allowed us to conclude that the gene is significantly up-regulated in tumour tissues when compared with normal mucosa. These results agree with those obtained by the analysis of three publicly available databases. EPDR1 up-regulation correlates with the TNM staging parameters, especially T and M. Studies with CRC cell lines revealed that the methylation of a CpG island controls EPDR1 expression. siRNA knocking-down and overexpression of the gene following transient plasmid transfection, showed that EPDR1 favours cell proliferation, migration, invasiveness and adhesion to type I collagen fibres, suggesting a role in epithelial to mesenchymal transition. Both statistical and functional analysis correlated EPDR1 overexpression with invasiveness and dissemination of tumour cells, supporting the inclusion of EPDR1 in panels of genes used to improve molecular subtyping of CRC. Eventually, EPDR1 may be an actionable target.

A New Surgical Model of Skeletal Muscle Injuries in Rats Reproduces Human Sports Lesions.

Skeletal muscle injuries are the most common sports-related injuries in sports medicine. In this work, we have generated a new surgically-induced skeletal muscle injury in rats, by using a biopsy needle, which could be easily reproduced and highly mimics skeletal muscle lesions detected in human athletes. By means of histology, immunofluorescence and MRI imaging, we corroborated that our model reproduced the necrosis, inflammation and regeneration processes observed in dystrophic mdx-mice, a model of spontaneous muscle injury, and realistically mimicked the muscle lesions observed in professional athletes. Surgically-injured rat skeletal muscles demonstrated the longitudinal process of muscle regeneration and fibrogenesis as stated by Myosin Heavy Chain developmental (MHCd) and collagen-I protein expression. MRI imaging analysis demonstrated that our muscle injury model reproduces the grade I-II type lesions detected in professional soccer players, including edema around the central tendon and the typically high signal feather shape along muscle fibers. A significant reduction of 30% in maximum tetanus force was also registered after 2 weeks of muscle injury. This new model represents an excellent approach to the study of the mechanisms of muscle injury and repair, and could open new avenues for developing innovative therapeutic approaches to skeletal muscle regeneration in sports medicine.

Can local corticosteroid injection in the retrocalcaneal bursa lead to rupture of the Achilles tendon and the medial head of the gastrocnemius muscle?

PURPOSE: The purpose of the study is to explain the cause-effect relationship in three patients who reported combined ruptures of the Achilles tendon and the gastrosoleus complex 6 months after they had received corticosteroids injections for the management of retrocalcaneal bursitis. METHODS: Three cryopreserved cadavers (three men, three left legs) were examined to assess the anatomic connection between the retrocalcaneal bursa and the Achilles tendon (distal and anterior fibers). Blue triptan medium contrast was injected. RESULTS: An unexpected connection between the retrocalcaneal bursa and the anterior fibers of the Achilles tendon was found in all instances. CONCLUSIONS: Local corticosteroid injection of the retrocalcaneal bursa may help the symptoms of retrocalcanear bursitis, but pose a risk of Achilles tendon rupture. This risk-benefit has to be taken into account when corticosteroid injections are prescribed to professional and high-level athletes.

Estudio seroepidemiológico del virus respiratorio sincitial bovino en el municipio de Montería, Colombia / Seroepidemiological study of the bovine respiratory sincitial virus in the municipality of Monteria, Colombia

Objetivo. El propósito de esta investigación fue realizar un estudio seroepidemiológico para detectar anticuerpos específicos contra el Virus Respiratorio Sincitial Bovino (BRSV) mediante la técnica comercial de ELISA (Bio-X ® BRSV Elisa Kit, Bruselas, Bélgica), con el fin de demostrar de manera indirecta, la presencia y circulación del VRSB en el municipio de Montería, Colombia. Materiales y métodos. Se recolectaron 163 muestras de sangre (137 de hembras y 26 de toros) de animales con antecedentes de infertilidad, pertenecientes a 28 fincas, los cuales provenían de 4 diferentes zonas equidistantes dentro del municipio. Todas las muestras fueron seleccionadas al azar. Se realizó un análisis descriptivo con los datos serológicos obtenidos de cada animal e interpretándolos con las variables: raza, edad, zona, tipo de explotación, sexo y alteraciones reproductivas. Para determinar la asociación entre seropositividad y cada una de las variables se utilizó la prueba de c2. No hubo diferencias significativas para ninguna de las variables analizadas. Resultados. Se detectaron anticuerpos en 22 de los animales seleccionados, lo que correspondió al 13% del total muestreado. Conclusiones. Este hallazgo constituye la demostración indirecta de la presencia del VRSB en el municipio de Montería, lo que sugiere la necesidad de estudios adicionales para determinar su participación en síndromes respiratorios y problemas reproductivos; de comprobarse sus implicaciones clínicas en hatos bovinos de esta región, sería necesario implementar medidas adecuadas para su control y prevención.

Caracterización biológica dedos aislados de Leptospiraspp procedentes de pacientes colombianos con síndrome de Weil

Leptospirosis en el humano o síndrome de Weil se caracteriza por ictericia progresiva, hemorragias de curso variable, insuficienciarenal o compromiso pulmonar (1). A pesar de los estudios realizados en algunos modelos animales sobre patogenicidad y virulencia de aislados de Leptospira, procedentes de casos humanos (2,3),se desconoce la virulencia y patogenicidad deaislados procedentes de pacientes colombianos.

Contextualización de las zoonosis bacterianas y virales transmitidas por roedores / Contextualization of bacterial and viral zoonoses transmitted by rodents

Hace un poco más de 3 años, registramos dentro del postgrado de biología de la Universidad de Antioquia, la línea de investigación en zoonosis emergentes y reemergentes; motivados por los, en aquel entonces, recientes eventos, que aparentemente involucraban la transmisión de Hantavirus desde roedores (1,2), e inspirado por la experiencia recién adquirida (finales del 2004), en investigación de Arenavirus y otros virus asociados con fiebres hemorrágica en laboratorios de Estados Unidos (Universidad de Wisconsin e Instituto de Virología Humana en Baltimore, Maryland (3), nos vimos estimulados a formular y proponer, en convenio con el Instituto Colombiano de Medicina Tropical (ICMT-CES), uno de los primeros estudios de Leptospirosis en roedores urbanos en Medellín (4), y más tarde, también con el ICMT y el laboratorio de Inmuno-virología, el estudio de Hantavirus, Arenavirus y Leptospira en roedores urbanos y silvestres y en humanos de la región de Urabá en Antioquia.

Ordered transcriptional factor recruitment and epigenetic regulation of tnf-alpha in necrotizing acute pancreatitis.

Tauhe expression of the critical initiator cytokine TNF-alpha was strongly upregulated in vivo in acute necrotic pancreatitis (AP) in rodents and in vitro in TNF-alpha activated acinar AR42J cells. Upregulation of tnf-alpha, inos, icam-1 and il-6 occurred both in TNF-alpha receptor 1 and 2 knock-out mice, but not in TNF-alpha knock-out mice, in cerulein-induced acute pancreatitis. Chromatin immunoprecipitation analysis showed that transcriptional factors (ELK-1, SP1, NF-kappaB and EGR-1) and chromatin modification complexes (HDAC1, HDAC2, GCN5, PCAF and CBP) were recruited and/or released from the promoter in a strictly ordered mechanism. Activation of tnf-alpha gene was also accompanied by an ordered increased level of histone H3K9, H3K14 and H3K18-acetylation and H3K4 methylation, as well as H4K5 acetylation. A better knowledge of the molecular mechanisms that control tnf-alpha gene regulation will provide deeper understanding of the initiation and development of the inflammatory processes occurring in acute pancreatitis triggered by TNF-alpha cytokine.

PAP1 signaling involves MAPK signal transduction.

Pancreatitis-associated protein 1 (PAP1) belongs to the Reg family of secretory proteins. Several important biological roles have been attributed to PAP1 but the signaling pathways activated by this protein remain only partially understood. Here, we describe the intracellular pathways triggered by PAP1 in a pancreatic acinar cell line. Taking advantage of the fact that PAP1 induces its own transcription, we performed ChIP assays to analyze the recruitment of transcriptional factors on its promoter. Our results show that PAP1 increased the transactivation activity of pap1 and the binding on its promoter of the nuclear factors C/EBPbeta, P-CREB, P-ELK1, EGR1, STAT3, and ETS2, which are downstream targets of MAPK signaling. p44/42, p38, and JNK MAPKs activity increased after PAP1 treatment. In addition, pharmacological inhibition of these kinases markedly inhibited the induction of pap1 mRNA. Taken together, these results indicated that the mechanism of PAP1 action involves the activation of the MAPK superfamily.

Asociación entre la presencia de Helicobacter pylori y patología gástrica detectadas por endoscopía / Association between the presence of Helicobacter pylori and gastric pathology detected by endoscopy

Con el objetivo de determinar la relación que existe entre la presencia de Helicobacter pylori en biopsia con las patologías gásticas detectadas por endoscopias, se realizó la presente investigación. Para ello se recopilaron datos de 1468 pacientes que se sometieron a este procedimiento y a quienes se les realizó biopsia gástrica en busca de la bacteria. La recolección de datos se efectuó por consulta de los registros médicos de los pacientes evaluados por los gastroenterólogos que colaboraron con el presente estudio y se obtuvo información acerca: edad, género, diagnóstico y presencia o ausencia de Helicobacter pilory en la biopsia realizada. Del total de 1468 pacientes, se encontró que 536 (36.5%) fueron hombres y 932 (63.5%) mujeres.

Seroprevalencia del virus de la Leucosis viral bovina en animales con trastornos reproductivos de Montería / Seroprevalencia of bovine leukemia virus in animals with reproductive problems in Monteria

Objetivo. Determinar la seroprevalencia de Leucosis Viral Bovina (LVB) en animales contrastornos reproductivos. Materiales y métodos. Se recolectaron 137 muestras de sangrede hembras con antecedentes de infertilidad, pertenecientes a 28 fincas distribuidas en elmunicipio de Montería; adicionalmente, se obtuvieron muestras al azar de 26 torospertenecientes a las mismas fincas que fueron analizadas para anticuerpos contra LVB. Latécnica serológica empleada fue la prueba de ELISA. Se realizó un análisis descriptivo tabulandola información con datos de seropositividad y seronegatividad obtenidos de cada animal; losresultados se interpretaron de acuerdo a las variables: raza, edad, sexo, zona, tipo deexplotación y evento o problema reproductivo detectado. Para determinar la asociaciónentre seropositividad y cada una de las variables se utilizó la prueba de χ2. Resultados. Laspruebas arrojaron una seroprevalencia del 21% para LVB. No se encontraron diferenciassignificativas de prevalencia asociadas a las variables raza, edad o estado reproductivo delos animales (p≥0.05), pero si entre la presencia de anticuerpos contra LVB y las variableszona, tipo de explotación y sexo. Conclusiones. Se demuestra la circulación del virus de laLVB en Montería, (Colombia). Se confirma la importancia de implementar un programa decontrol y prevención de la diseminación de la infección, con el fin de evitar las pérdidaseconómicas asociadas, y dentro de lo posible, la eliminación de los especímenes seropositivospara lograr la erradicación de la infección en esta zona del país.

Fast and slow myosins as markers of muscle injury.

OBJECTIVE: The diagnosis of muscular lesions suffered by athletes is usually made by clinical criteria combined with imaging of the lesion (ultrasonography and/or magnetic resonance) and blood tests to detect the presence of non-specific muscle markers. This study was undertaken to evaluate injury to fast and slow-twitch fibres using specific muscle markers for these fibres. METHODS: Blood samples were obtained from 51 non-sports people and 38 sportsmen with skeletal muscle injury. Western blood analysis was performed to determine fast and slow myosin and creatine kinase (CK) levels. Skeletal muscle damage was diagnosed by physical examination, ultrasonography and magnetic resonance and biochemical markers. RESULTS: The imaging tests were found to be excellent for detecting and confirming grade II and III lesions. However, grade I lesions were often unconfirmed by these techniques. Grade I lesions have higher levels of fast myosin than slow myosin with a very small increase in CK levels. Grade II and III lesions have high values of both fast and slow myosin. CONCLUSIONS: The evaluation of fast and slow myosin in the blood 48 h after the lesion occurs is a useful aid for the detection of type I lesions in particular, since fast myosin is an exclusive skeletal muscle marker. The correct diagnosis of grade I lesions can prevent progression of the injury in athletes undergoing continual training sessions and competitions, thus aiding sports physicians in their decision making.

Vacunas antivirales de última generación / Antiviral vaccines of last generation

Una muestra de lo que ha representado la vacunología desde la "explosión" de técnicas moleculares disponibles para la manipulación de los ácidos nucleicos y las proteinas, un campo promisorio con visos de ciencia ficción que aún no da los frutos esperados.

A short training programme for the rapid improvement of both aerobic and anaerobic metabolism.

The aim of this study was to evaluate the changes in aerobic and anaerobic metabolism produced by a newly devised short training programme. Five young male volunteers trained daily for 2 weeks on a cycle ergometer. Sessions consisted of 15-s all-out repetitions with 45-s rest periods, plus 30-s all-out repetitions with 12-min rest periods. The number of repetitions was gradually increased up to a maximum of seven. Biopsy samples of the vastus lateralis muscle were taken before and after training. Performance changes were evaluated by two tests, a 30-s all-out test and a maximal progressive test. Significant increases in phosphocreatine (31%) and glycogen (32%) were found at the end of training. In addition, a significant increase was observed in the muscle activity of creatine kinase (44%), phosphofructokinase (106%), lactate dehydrogenase (45%), 3-hydroxy-acyl-CoA dehydrogenase (60%) and citrate synthase (38%). After training, performance of the 30-s all-out test did not increase significantly, while in the maximal progressive test, the maximum oxygen consumption increased from mean (SD) 57.3 (2.6) ml x min(-1) x kg(-1) to 63.8 (3.0) ml min(-1) x kg(-1), and the maximum load from 300 (11) W to 330 (21) W; all changes were significant. In conclusion, this new protocol, which utilises short durations, high loads and long recovery periods, seems to be an effective programme for improving the enzymatic activities of the energetic pathways in a short period of time.

The distribution of rest periods affects performance and adaptations of energy metabolism induced by high-intensity training in human muscle.

The effect of the distribution of rest periods on the efficacy of interval sprint training is analysed. Ten male subjects, divided at random into two groups, performed distinct incremental sprint training protocols, in which the muscle load was the same (14 sessions), but the distribution of rest periods was varied. The 'short programme' group (SP) trained every day for 2 weeks, while the 'long programme' group (LP) trained over a 6-week period with a 2-day rest period following each training session. The volunteers performed a 30-s supramaximal cycling test on a cycle ergometer before and after training. Muscle biopsies were obtained from the vastus lateralis before and after each test to examine metabolites and enzyme activities. Both training programmes led to a marked increase (all significant, P < 0.05) in enzymatic activities related to glycolysis (phosphofructokinase - SP 107%, LP 68% and aldolase - SP 46%, LP 28%) and aerobic metabolism (citrate synthase - SP 38%, LP 28.4% and 3-hydroxyacyl-CoA dehydrogenase - SP 60%, LP 38.7%). However, the activity of creatine kinase (44%), pyruvate kinase (35%) and lactate dehydrogenase (45%) rose significantly (P < 0.05) only in SP. At the end of the training programme, SP had suffered a significant decrease in anaerobic ATP consumption per gram muscle (P < 0.05) and glycogen degradation (P < 0.05) during the post-training test, and failed to improve performance. In contrast, LP showed a marked improvement in performance (P < 0.05) although without a significant increase in anaerobic ATP consumption, glycolysis or glycogenolysis rate. These results indicate that high-intensity cycling training in 14 sessions improves enzyme activities of anaerobic and aerobic metabolism. These changes are affected by the distribution of rest periods, hence shorter rest periods produce larger increase in pyruvate kinase, creatine kinase and lactate dehydrogenase. However, performance did not improve in a short training programme that did not include days for recovery, which suggests that muscle fibres suffer fatigue or injury.

DNA methylation and histone acetylation of rat methionine adenosyltransferase 1A and 2A genes is tissue-specific.

Methionine adenosyltransferase (MAT) catalyzes the biosynthesis of S-adenosylmethionine (AdoMet). In mammals MAT activity derives from two separate genes which display a tissue-specific pattern of expression. While MAT1A is expressed only in the adult liver, MAT2A is expressed in non-hepatic tissues. The mechanisms behind the selective expression of these two genes are not fully understood. In the present report we have evaluated MAT1A and MAT2A methylation in liver and in other tissues, such as kidney, by methylation-sensitive restriction enzyme digestion of genomic DNA. Our data indicate that MAT1A is hypomethylated in liver and hypermethylated in non-expressing tissues. The opposite situation is found for MAT2A. Additionally, histones associated to MAT1A and MAT2A genes showed enhanced levels of acetylation in expressing tissues (two-fold for MAT1A and 3.5-fold for MAT2A liver and kidney respectively). These observations support a role for chromatin structure and its modification in the tissue-specific expression of both MAT genes.

Liver-specific methionine adenosyltransferase MAT1A gene expression is associated with a specific pattern of promoter methylation and histone acetylation: implications for MAT1A silencing during transformation.

Methionine adenosyltransferase (MAT) is the enzyme that catalyzes the synthesis of S-adenosylmethionine (AdoMet), the main donor of methyl groups in the cell. In mammals MAT is the product of two genes, MAT1A and MAT2A. MAT1A is expressed only in the mature liver whereas fetal hepatocytes, extrahepatic tissues and liver cancer cells express MAT2A. The mechanisms behind the tissue and differentiation state specific MAT1A expression are not known. In the present work we examined MAT1A promoter methylation status by means of methylation sensitive restriction enzyme analysis. Our data indicate that MAT1A promoter is hypomethylated in liver and hypermethylated in kidney and fetal rat hepatocytes, indicating that this modification is tissue specific and developmentally regulated. Immunoprecipitation of mononucleosomes from liver and kidney tissues with antibodies mainly specific to acetylated histone H4 and subsequent Southern blot analysis with a MAT1A promoter probe demonstrated that MAT1A expression is linked to elevated levels of chromatin acetylation. Early changes in MAT1A methylation are already observed in the precancerous cirrhotic livers from rats, which show reduced MAT1A expression. Human hepatoma cell lines in which MAT1A is not expressed were also hypermethylated at this locus. Finally we demonstrate that MAT1A expression is reactivated in the human hepatoma cell line HepG2 treated with 5-aza-2'-deoxycytidine or the histone deacetylase inhibitor trichostatin, suggesting a role for DNA hypermethylation and histone deacetylation in MAT1A silencing.

Histone deacetylase. A key enzyme for the binding of regulatory proteins to chromatin.

Core histones can be modified by reversible, posttranslational acetylation of specific lysine residues within the N-terminal protein domains. The dynamic equilibrium of acetylation is maintained by two enzyme activities, histone acetyltransferase and histone deacetylase. Recent data on histone deacetylases and on anionic motifs in chromatin- or DNA-binding regulatory proteins (e.g. transcription factors, nuclear proto-oncogenes) are summarized and united into a hypothesis which attributes a key function to histone deacetylation for the binding of regulatory proteins to chromatin by a transient, specific local increase of the positive charge in the N-terminal domains of nucleosomal core histones. According to our model, the rapid deacetylation of distinct lysines in especially H2A and H2B would facilitate the association of anionic protein domains of regulatory proteins to specific nucleosomes. Therefore histone deacetylation (histone deacetylases) may represent a unique regulatory mechanism in the early steps of gene activation, in contrast to the more structural role of histone acetylation (histone acetyltransferases) for nucleosomal transitions during the actual transcription process.