Célula Adentro (Jogos educativos)

O Célula Adentro é um jogo de tabuleiro onde os jogadores são desafiados a resolver diferentes casos a respeito da célula. Como investigadores, cada equipe deverá juntar evidências, usar sua capacidade de raciocínio e dedução, e desvendar alguns dos mistérios da célula.

Caracterización del accidente con riesgo biológico en estudiantes de pregrado en facultades de salud en una institución de educación superior de Bogotá 2009-2010 / Characterization of the accident with biohazard risk in undergraduate students in health schools and in institutions of higher education of Bogotá 2009-2010

Objetivo: caracterizar el accidente por exposición al riesgo biológico en los estudiantes de las facultades de enfermería, medicina y odontología de la Institución de Educación Superior (IES) 2009-2010. Metodología: estudio descriptivo mixto y retrospectivo. Para identificar estudiantes accidentados, se aplicó por conveniencia una encuesta cerrada y autodiligenciada a estudiantes de pregrado, matriculados en las facultades participantes entre junio de 2009 y junio de 2010. Para la descripción del accidente, se empleó una entrevista semiestructurada, de participación voluntaria, mediante búsqueda activa de casos, aplicada a los estudiantes identificados como siniestrados a través de la estadística reportada por la póliza estudiantil de accidentes. Resultados: en la caracterización de la accidentalidad con exposición al riesgo biológico en el estudiante de pregrado de las facultades de salud, se encontró un porcentaje de reporte del evento por debajo de lo encontrado en otros estudios (1, 2). De los estudiantes que refirieron haber sufrido algún accidente con exposición a riesgo biológico, entre el 50% y el 72% solicitó atención de urgencias mientras que entre el 56% y el 79% refirieron haber reportado el caso a Bienestar Universitario; en lo referente al mecanismo de transmisión, entre el 56% y el 94% de los eventos referidos fueron ocasionados con material cortopunzante afectando principalmente miembro superior; el segundo mecanismo de exposición reportado fue la exposición de mucosas oculares con sangre o fluidos corporales con un 44% de eventos referidos por los estudiantes de medicina, mientras que para los estudiantes de las facultades de enfermería y odontología fue alrededor del 5%. En cuanto al sitio de ubicación del evento, los estudiantes de las facultades de enfermería y odontología refirieron una mayor proporción de ocurrencia en los centros de práctica formativa extramurales a la IES, mientras que los estudiantes de odontología refirieron una mayor frecuencia de ocurrencia en las clínicas odontológicas, ubicadas en las instalaciones de la Universidad; lo anterior se explica en virtud de la distribución geográfica de los centros de práctica formativa para cada programa académico. En el abordaje cualitativo de la descripción del accidente con riesgo biológico, se establecieron como categorías de análisis: el acompañamiento, las técnicas de procedimiento, la solicitud de atención en urgencias, el seguimiento y las lecciones aprendidas. El estudio permitió identificar que la presencia del docente en el campo de práctica facilita la atención del estudiante en el momento del evento; así mismo que los estudiantes identifican que la falta de adherencia a las normas o estándares de bioseguridad es un factor que incide en la ocurrencia del evento. Los participantes manifestaron que para ser atendidos en el servicio de urgencias, debieron desplazarse con las muestras sanguíneas del individuo fuente desde el sitio de ocurrencia del evento al de atención; el transporte de las muestras fue realizado por el estudiante, sin el debido cumplimiento del protocolo de transporte de muestras sanguíneas y ya en el servicio de urgencias, la atención tardó en promedio tres horas. El seguimiento del caso por Bienestar Universitario no es claro para los participantes del estudio y el principal temor se relaciona con la posibilidad de desarrollar en el largo plazo una enfermedad por virus de transmisión hemática y fluidos corporales. Se resalta que los estudiantes identifican la necesidad de modificar la práctica de medidas de bioseguridad y comprometerse con la adherencia a las normas o estándares de bioseguridad como una estrategia efectiva para evitar el accidente con riesgo biológico. Conclusiones: la IES debe fortalecer las estrategias de prevención del accidente con riesgo biológico en el marco del los convenios docencia servicio, para promover el bienestar del estudiante de las facultades de salud en el desarrollo de las prácticas formativas, de manera que se minimice el riesgo inherente a estas. Debe establecer mecanismos para asegurar el reporte de los eventos y en la misma medida favorecer la calidad en la atención al estudiante de pregrado. Se deben reforzar las estrategias que permitan a los estudiantes ser responsables de su autocuidado y a la vez permitan su adherencia a las normas de bioseguridad; ampliar el conocimiento del uso de elementos de protección y los procedimientos a seguir de presentarse el accidente.

Prognostic value of the detection of lymph node micrometastases in colon cancer

INTRODUCTION AND OBJECTIVES: A study is made of the clinical repercussions of occult metastases-micrometastases (MMs+)-or isolated tumour cells (ITCs+) in the lymph nodes of patients with stage IIA and IIB colon adenocarcinoma initially considered as corresponding to N0. MATERIAL AND METHODS: A retrospective study of 39 patients with stage IIA and IIB (T3-T4 N0 M0) colon adenocarcinoma, subjected to similar surgical and adjuvant chemotherapy treatment, with long and careful follow-up (minimum: 5 years, mean: 81.7 months) was performed on their previously resected lymph nodes, with the aid of new histological and immunohistochemical (cytokeratin) sections, in order to detect MMs or ITCs. Disease-free survival (DFS) and global survival (GS) in the two groups (patients with MMs+ or ITCs+ vs. patients without MMs or ITCs) were compared at 5 years based on the corresponding Kaplan-Meier survival curves, with the Breslow test. RESULTS: A total of 382 lymph nodes from the 39 patients (mean: 9.8; standard deviation: 6.09) were revised. MMs+ were detected in 2 cases and ITCs+ in 2 more cases on the Cytokeratin study. GS of the whole series at 5 years was 89.74% (35 patients alive) with a DFS at 5 years of 79.49% (31 patients free of disease), but the 2 cases with MMs+ were dead at 5 years, with high statistical differences between both groups (MMs+/MMs-) (p<0.0001). When comparing the group of MMs+/ITCs+ patients and the group of MM-/ITCs- patients, the DFS and GS times at 5 years were higher in the MMs-/ITCs- group (p=0.0692 and p=0.006 respectively). CONCLUSIONS: Although the incidence of MMs+ or ITCs+ in the examined lymph nodes was low, the presence of MMs is related to a dramatic reduction in GS and DFS at 5 years. We encourage a detailed histological study of lymph nodes resected in patients with deep penetrating colon tumours in order to assure a pN0 status (AU)

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Diagnóstico de leptospirosis mediante la PCR en pacientes con síndrome febril icterohemorrágico / PCR leptospirosis diagnosis in patients with ictohaemorrhagic fever syndrome

El objetivo del estudio fue evaluar la utilidad de la PCR en el diagnóstico de la leptospirosis humana, utilizando dos pares de iniciadores específicos para las leptospiras patógenas. Se examinaron por la prueba serológica MAT y la PCR muestras de orina y suero de 73 pacientes con SFIH y epidemiología compatible con leptospirosis. Muestras de 10 pacientes (55,5%) con diagnóstico confirmado de leptospirosis por MAT resultaron positivas por PCR. El 28% de los sueros de pacientes clasificados por serología como casos no confirmados resultó PCR positivo, lo que demuestra el valor de la PCR en el diagnóstico temprano de la leptospirosis humana. La comparación de los resultados de PCR en muestras de orina y suero determinó una mayor sensibilidad de esta técnica en muestras de orina. Considerando las diferentes fases de la leptospirosis en el análisis de los resultados de la PCR, se demostró la utilidad de las muestras de orina en el diagnóstico precoz de la enfermedad. Se concluye que la PCR es un método sensible y específico que aplicado en muestras clínicas y de manera complementaria a las pruebas serológicas sirve para detectar casos de leptospirosis, especialmente en pacientes graves en los que es necesario hacer diagnóstico diferencial.

The purpose of this study was to evaluate the usefulness of PCR for the diagnosis of human leptospirosis using two pairs of specific pathogenic Leptospira initiators. Urine and serum samples from 73 patients with ictohaemorrhagic fever syndrome (IHFS) epidemiologically compatible for leptospirosis were examined by the MAT serologic test and by PCR. Ten (55.5%) samples from patients with MAT confirmed leptospirosis were also PCR positive. Sera from 28% of patients classified as non serologically confirmed cases were PCR positive, which shows the importance of PCR for the early diagnosis of human leptospirosis. A comparison of the PCR results in urine and serum samples determined the greater sensibility of this technique in urine samples. The usefulness of urine samples for the early diagnosis of leptospirosis was demonstrated by considering the different leptospirosis phases in the analysis of the PCR results. It is concluded that PCR is a sensitive and specific method which, applied to clinical samples and as complement to serological tests, if useful to detect leptospirosis cases, especially in patients with severe symptoms, when it is necessary to reach a differential diagnosis.

Carcinomatosis peritoneal mucinosa tratada con cisplatino (CDDP) intraperitoneal y 5-FU endovenoso / Mucinous peritoneal carcinomatosis treated with intraperitoneal cisplatin (CDDP) and intravenous 5-FU

• Propósito: describir el tratamiento de una entidad clínica poco frecuente de curso clínico variable.• Material y método: se presenta el caso de un paciente con carcinomatosis peritoneal mucinosa, varianteintermedia.• Resultados y conclusiones: una cirugía de citoreducción adecuada, seguida de quimioterapia conCDDP Intraperitoneal (IP) y 5FU ev, puede lograr una larga supervivencia en pacientes afectos de carcinomatosisperitoneal, con buena tolerancia al tratamiento

• Purpose: To describe the treatment of a slightly frequent clinical entity of variable clinical course.• Material and methods: We present the case of a patient with mucinous peritoneal carcinomatosis,intermediate variant.• Results and conclusion: A suitable cytoreductive surgery, followed by chemotherapy withintraperitoneal CDDP and intravenous 5-FU, can achieve a long survival of patients with peritonealcarcinomatosis, with good tolerance for the treatment

[Technical quality control of chest x-rays for the health surveillance of workers exposed to the risk of pneumoconiosis: proposal for a qualitative screening method]. / Controllo di qualità tecnica sui radiogrammi del torace effettuati per la sorveglianza sanitaria dei lavoratori esposti al rischio di pneumoconiosi: proposta di un metodo di screening qualitativo.

BACKGROUND: The necessity of a qualitative screening has arisen from the fact that good technical quality is of fundamental importance for evaluating initial pneumoconiosis, for reducing inter- and intra-reader variability, for effective secondary prevention and for forensic medicine purposes. OBJECTIVES: The authors report experience in use of a method to evaluate the quality of chest radiographs performed in health surveillance programs for workers at risk for development of pneumoconiosis. METHODS: 747 postero-anterior chest radiographs concerning employees of 21 ceramic factories in the Province of Viterbo were examined. A standardized pattern was created for this evaluation. The pattern considers the main factors that can influence the quality of chest radiographs and assigns points for each of them. That factors are: 1) reproduced image of the lung's vascular structure, chiefly in the peripheral portions; 2) reproduced image of heart border, aorta, diaphragm; 3) deep inspiration; 4) symmetric image of the chest; 5) position of the scapulae; 6) visualization of the costal-phrenic angles; 7) technical impairments. RESULTS: The application of the method revealed that half of the chest radiographs examined had poor image quality for a suitable reading, in conformity with the ILO 1980 guidelines. The critical points are poor visualization of the lung's vascular structure due to overexposure or underexposure, technical impairments, non-correct scapulae position. CONCLUSIONS: The authors believe that the suggested method can be a useful instrument for self-testing the quality of chest radiographs performed in radiology centers and for the National Health Service to test the quality of chest radiographs performed in health surveillance programs.

[Growing skull fracture in childhood. Presentation of 12 cases]. / Fractura evolutiva de cráneo en la infacia. Presentación de 12 casos.

Growing skull fractures (GSF) are rare complications of head injury (HI) in childhood. This entity consists of a skull fracture with an underlying dural tear that courses with a progressive enlargement of the fracture to produce a cranial defect. The pathophysiology and some aspects of its management are still controversial. In this review we present 12 patients diagnosedd and treated for a GSF at our institution between 1980 and 2002. 11 patients were under the age of 3 years and one patient was 5 years old at the moment of HI. The most common cause of injury was a fall from height. In the initial plain x-rayfilms, 11 patients showed a diastatic skull fracture and one patient only had a linear fracture. At this time, CT scan showed cortical contussion underlying the fracture in every case. The mean time between injury and presentation of GSF was 11.6 weeks. Diagnosis was made by palpation of the cranial defect and confirmed with skull x-rayfilms. The most frecuent location of GSF was in the parietal region. Associated lesions like hydrocephalus, encephalomalacia, lepto-menigeal cysts, brain tissue herniation and ipsilateral ventricular dilatation, were found in the preoperative CT or MRI. All patients underwent a dural repair with pericranium or fascia lata. The cranial defect was covered with local calvarial bone fragments in every case. Only one patient needed a cranioplasty with titanium mesh. Every child with a skull fracture must be followed until the fracture heals. Patients under the age of 3 years with a diastatic fracture and a dural tear, demostrated by TC or MRI, are more prone to develop GSF. In these cases, early repair must be adviced in order to prevent progressive brain damage.

Fractura evolutiva de cráneo en la infancia. Presentación de 12 casos / Growing skull fracture in childhood. Presentation of 12 cases

La fractura evolutiva de cráneo (FEC) es una complicación poco frecuente del traumatismo craneoencefálico (TCE) en la infancia. Consiste en una fractura con un desgarro dural subyacente, que se ensancha progresivamente hasta constituir un defecto craneal. Su fisiopatología, así como algunos aspectos del manejo terapéutico, son todavía controvertidos. Se presenta una revisión retrospectiva de 12 casos diagnosticados y tratados entre los años 1980 y 2002 en nuestra institución. Once pacientes eran menores de 3 años y uno tenía 5 años en el momento del traumatismo. La causa más frecuente de TCE fue la caída. En la radiografía inicial, 11 pacientes tenían fracturas con diastasis y solamente un paciente tenía fractura lineal. El hallazgo tomográfico común a todos los casos fue contusión cortical subyacente a la fractura. El intervalo promedio entre traumatismo y presentación de las FEC fue de 11,6 semanas. La localización preferente de las FEC fue en la región parietal. El diagnóstico se hizo por palpación de un defecto craneal y se confirmó con radiografía. Se encontraron lesiones asociadas en la TAC y RMN preoperatoria, como hidrocefalia, encefalomalacia, quistes leptomeníngeos, herniatión de tejido encefálico y dilatación ventricular ipsilateral. Todos los pacientes fueron sometidos a reparación plástica de la duramadre y el defecto craneal se cubrió con fragmentos óseos. Sólo un paciente precisó craneoplastia con malla de titanio. Todas las fracturas de cráneo en edad pediátrica deben controlarse hasta constatar su reparación. Los pacientes menores de 3 años con fracturas inicialmente diastasadas y con evidencia en la TAC o RMN de laceración dural, tienen mayor probabilidad de desarrollar una FEC. En estos casos se recomienda el tratamiento precoz para evitar un daño cerebral progresivo (AU)

[Unusual abdominal complication of ventriculoperitoneal shunt]. / Complicación abdominal poco frecuente de las derivaciones ventrículoperitoneales. Caso clínico.

The most common complications after CSF shunting to treat hydrocephalus are shunt infection and obstruction. Although ventriculoperitoneal (VP) diversion of the CSF using artificial shunt devices is an accepted method for the management of hydrocephalus, high rates of various complications have been reported, ranging from 24% to 47%. Among these, abdominal complications account for approximately 25%. The incidence of bowel perforation by shunt-catheter is known to be as low as 0.1-0.7%. We describe a case of migration af a peritoneal catheter through a congenital hernia of Morgagni.

Complicación abdominal poco frecuente de las derivaciones ventrículoperitoneales. Caso clínico / Unusual abdominal complication of ventrículoperitoneal shunt

Las complicaciones más frecuentes de las derivaciones ventrículoperitoneales en el tratamiento de la hidrocefalia son la infección y la obstrucción, oscilando estas últimas entre 24 y 47 por ciento, y dentro de ellas, las complicaciones abdominales representan aproximadamente un 25 por ciento. La incidencia de perforación diafragmática es relativamente escasa, aceptándose entre un 0,1-0,7 por ciento La migración del catéter peritoneal a través de hernias inguinales es relativamente frecuente dada su mayor incidencia, mientras que en las hernias de Morgagni la frecuencia es mucho menor (aproximadamente 1/4000-5000).Presentamos un caso de migración del extremo distal del catéter peritoneal a través de una hernia congénita de Morgagni (AU)

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Mapping of calmodulin and Gbetagamma binding domains within the C-terminal region of the metabotropic glutamate receptor 7A.

Ca(2+)/calmodulin (Ca(2+)/CaM) and the betagamma subunits of heterotrimeric G-proteins (Gbetagamma) have recently been shown to interact in a mutually exclusive fashion with the intracellular C terminus of the presynaptic metabotropic glutamate receptor 7 (mGluR 7). Here, we further characterized the core CaM and Gbetagamma binding sequences. In contrast to a previous report, we find that the CaM binding motif localized in the N-terminal region of the cytoplasmic tail domain of mGluR 7 is conserved in the related group III mGluRs 4A and 8 and allows these receptors to also bind Ca(2+)/CaM. Mutational analysis of the Ca(2+)/CaM binding motif is consistent with group III receptors containing a conventional CaM binding site formed by an amphipathic alpha-helix. Substitutions adjacent to the core CaM target sequence selectively prevent Gbetagamma binding, suggesting that the CaM-dependent regulation of signal transduction involves determinants that overlap with but are different from those mediating Gbetagamma recruitment. In addition, we present evidence that Gbetagamma uses distinct nonoverlapping interfaces for interaction with the mGluR 7 C-terminal tail and the effector enzyme adenylyl cyclase II, respectively. Although Gbetagamma-mediated signaling is abolished in receptors lacking the core CaM binding sequence, alpha subunit activation, as assayed by agonist-dependent GTPgammaS binding, was not affected. This suggests that Ca(2+)/CaM may alter the mode of group III mGluR signaling from mono- (alpha) to bidirectional (alpha and betagamma) activation of downstream effector cascades.

Pott's puffy tumour: still not an eradicated entity.

Pott's puffy tumour is an infrequent entity characterised by one or more subperiosteal abscesses associated with frontal bone osteomyelitis. Although cases in patients of all ages have been reported, teenagers are the most frequently affected. Early diagnosis and aggressive treatment are essential because of the high risk of severe neurological complications, such as epidural abscess, subdural empyema, and secondary septic thrombosis of the dural sinuses. This paper describes the case of a patient with a subperiosteal abscess resulting from sinusitis, with orbital and intracranial extension, and subsequent neurological complications. Despite modern methods of diagnosis and treatment, 13 new cases have been published in the last 5 years; in at least 3 (23%) of these cases there were serious neurological complications. Upper respiratory infections and sinusitis are leading causes of visits to the emergency department in the paediatric age group; however, no risk factors for poor outcome have so far been identified in any of these patients.

Suramin and the suramin analogue NF307 discriminate among calmodulin-binding sites.

Calmodulin-binding sites on target proteins show considerable variation in primary sequence; hence compounds that block the access of calmodulin to these binding sites may be more selective than compounds that inactivate calmodulin. Suramin and its analogue NF307 inhibit the interaction of calmodulin with the ryanodine receptor. We have investigated whether inhibition of calmodulin binding to target proteins is a general property of these compounds. Suramin inhibited binding of [(125)I]calmodulin to porcine brain membranes and to sarcoplasmic reticulum from skeletal muscle (IC(50)=4.9+/-1.2 microM and 19.9+/-1.8 microM, respectively) and blocked the cross-linking of [(125)I]calmodulin to some, but not all, target proteins in brain membranes by [(125)I]calmodulin. Four calmodulin-binding proteins were purified [ryanodine receptor-1 (RyR1) from rabbit skeletal muscle, neuronal NO synthase (nNOS) from Sf9 cells, G-protein betagamma dimers (Gbetagamma) from porcine brain and a glutathione S-transferase-fusion protein comprising the C-terminal calmodulin-binding domain of the metabotropic glutamate receptor 7A (GST-CmGluR7A) from bacterial lysates]. Three of the proteins employed (Gbetagamma, GST-CmGluR7A and RyR1) display a comparable affinity for calmodulin (in the range of 50-70 nM). Nevertheless, suramin and NF307 only blocked the binding of Gbetagamma and RyR1 to calmodulin-Sepharose. In contrast, the association of GST-CmGluR7A and nNOS was not impaired, whereas excess calmodulin uniformly displaced all proteins from the matrix. Thus suramin and NF307 are prototypes of a new class of calmodulin antagonists that do not interact directly with calmodulin but with calmodulin-recognition sites. In addition, these compounds discriminate among calmodulin-binding motifs.

Isolation and microsequencing of a novel cotinine receptor.

1. Nicotine and its main derivative. cotinine, are reported to have distinct central activities in mammals. In this study, the cotinine receptor was separated by biochemical procedures including radio receptor, affinity-chromatography, SDS-PAGE, and N-terminal sequencing assays. 2. Consistently, the results showed that distinctive cotinine receptors exist in different tissues of mammals. In rat brain, the affinity chromatography and [125I]cotinine receptor essays were used to isolate a 40-kDa protein (p40) with higher affinity for cotinine than alpha-bungarotoxin and nicotine. The N-terminus amino acid sequences of the p40 and its internal tryptic peptides showed no identity to recently described protein sequences, with the exception of homology to the human p205 synovial fluid protein. 3. These results, in agreement with other behavioral studies, are the first molecular evidence for distinctive nicotine and cotinine receptors in mammals.

Binding of calmodulin to the D2-dopamine receptor reduces receptor signaling by arresting the G protein activation switch.

Signaling by D(2)-dopamine receptors in neurons likely proceeds in the presence of Ca(2+) oscillations. We describe here the biochemical basis for a cross-talk between intracellular Ca(2+) and the D(2) receptor. By activation of calmodulin (CaM), Ca(2+) directly inhibits the D(2) receptor; this conclusion is based on the following observations: (i) The receptor contains a CaM-binding motif in the NH(2)-terminal end of the third loop, a domain involved in activating G(i/o). A peptide fragment encompassing this domain (D2N) bound dansylated CaM in a Ca(2+)-dependent manner (K(D) approximately 0.1 micrometer). (ii) Activation of purified Galpha(i1) by D2N, and D(2) receptor-promoted GTPgammaS (guanosine 5'-(3-O-thio)triphosphate) binding in membranes was suppressed by Ca(2+)/CaM (IC(50) approximately 0.1 micrometer). (iii) If Ca(2+) influx was elicited in D(2) receptor-expressing HEK293 cells, agonist-dependent inhibition of cAMP formation decreased. This effect was not seen with other G(i)-coupled receptors (A(1)-adenosine and Mel(1A)-melatonin receptor). (iv) The D(2) receptor was retained by immobilized CaM and radiolabeled CaM was co-immunoprecipitated with the receptor. Specifically, inhibition by CaM does not result from uncoupling the D(2) receptor from its cognate G protein(s); rather, CaM directly targets the D(2) receptor to block the receptor-operated G protein activation switch.

Two different signaling mechanisms involved in the excitation of rat sympathetic neurons by uridine nucleotides.

UTP stimulates transmitter release and inhibits M-type K(+) channels in rat superior cervical ganglion neurons via G protein-coupled P2Y receptors. To investigate the underlying signaling mechanisms, we treated the neurons with either pertussis or cholera toxin; neither treatment altered the inhibition of M-type K(+) channels by 10 microM UTP. However, pertussis toxin reduced UTP-evoked [(3)H]noradrenaline release by 66%. UTP, UDP, ATP, and ADP caused accumulation of inositol trisphosphate in a pertussis toxin-insensitive manner. Pharmacological inhibition of inositol trisphosphate-induced Ca(2+) release (by inhibition of phospholipase C, of inositol trisphosphate receptors, and of the endoplasmic Ca(2+)-ATPase) prevented the UTP-dependent inhibition of M currents but failed to alter UTP-evoked [(3)H]noradrenaline release. Chelation of intracellular Ca(2+) by 1,2-bis(2-aminophenoxy)ethane-N, N,N',N'-tetraacetic acid also reduced the inhibition of M currents by UTP. In addition, all these manipulations attenuated the inhibition of M currents by bradykinin, but hardly affected the inhibitory action of oxotremorine M. These results demonstrate that UTP inhibits M-type K(+) channels via an inositol trisphosphate-dependent signaling cascade that is also used by bradykinin but not by muscarinic acetylcholine receptors. In contrast, the secretagogue action of UTP is largely independent of this signaling cascade but involves pertussis toxin-sensitive G proteins. Thus, UTP-sensitive P2Y receptors excite sympathetic neurons via at least two different signal transduction mechanisms.

Tratamiento del cáncer colorrectal: encuesta de la Sociedad Valenciana de Cirugía / Management of colorectal cancer: a survey by the Surgical Society of Valencia

Introducción. Motivados por conocer la situación actual del tratamiento del cáncer colorrectal en los hospitales de la Comunidad Valenciana, y por encargo de la Sociedad Valenciana de Cirugía, se elaboró una encuesta dirigida a todos los Servicios de Cirugía General y Aparato Digestivo de estos centros, cuyo resultado exponemos. Material y método. Se realizó un análisis retrospectivo mediante encuesta, y se obtuvieron los datos desde el año 1997 hacia atrás, agrupándolos por años naturales. La encuesta abordó siete apartados del tratamiento del cáncer colorrectal (diagnóstico, cirugía programada, cirugía de urgencias, terapéutica adyuvante, enfermedad avanzada, seguimiento y anatomía patológica), y se estudiaron tanto parámetros de estructura como de proceso, así como los resultados de los mismos. Resultados. Se remitieron un total de 20 cuestionarios obteniéndose 17 respuestas (85 por ciento). Sólo 2 hospitales (11,7 por ciento) disponen de ecografía endorrectal. Ninguno realiza por sistema enema de doble contraste. Únicamente en 3 hospitales (17,64 por ciento), el cáncer rectal es tratado por un grupo determinado de cirujanos. Cinco hospitales (29,4 por ciento) realizan con asiduidad el lavado colónico intraoperatorio en la cirugía del cáncer obstructivo. Siete centros (41,1 por ciento) llevan a cabo algún tipo de terapéutica adyuvante preoperatoria en el cáncer rectal, siendo la cifra total de recidivas locales del 11,58 por ciento a los 2 años de seguimiento. No existe ningún protocolo establecido de seguimiento postoperatorio de estos pacientes en 3 hospitales (17,64 por ciento). El número medio de ganglios aislados por pieza quirúrgica es de nueve, y sólo 2 centros (11,7 por ciento) reflejan en sus informes anatomopatológicos la afectación del margen circunferencial. Conclusiones. De los resultados obtenidos en esta encuesta y su posterior comparación con la bibliografía concluimos: a) en el aspecto diagnóstico, se debe mejorar el porcentaje de colonoscopias completas; los enemas opacos, cuando se realicen, deberían llevarse a cabo sistemáticamente mediante la técnica de doble contraste; sería aconsejable implantar la ecografía endorrectal como exploración de rutina para la correcta estadificación del cáncer rectal con el fin de realizar una correcta selección de los pacientes candidatos a terapéutica adyuvante preoperatoria; b) en la cirugía electiva, dado que la cirugía del cáncer rectal depende del cirujano, creemos que debería ser realizada por personal especialmente entrenado; c) respecto a la cirugía del cáncer colorrectal obstructivo, si las condiciones del paciente lo permiten, debería tratarse de aumentar el porcentaje de resecciones con anastomosis primaria, entrenando al equipo quirúrgico en la realización del lavado intraoperatorio; d) se necesitan estudios prospectivos para valorar el régimen terapéutico adyuvante preoperatorio más adecuado; e) es recomendable que los distintos hospitales dispongan de protocolos de seguimiento postoperatorio homogéneos, con la finalidad de uniformizar el control de estos pacientes, además de prestarles un apoyo psicológico y servir de auditoría de sus propios resultados, y f) debe tratarse de que en los informes anatomopatológicos se especifique el margen circunferencial, así como intensificar el aislamiento de ganglios linfáticos a fin de evitar la infraestadificación tumoral (AU)

Calmodulin dependence of presynaptic metabotropic glutamate receptor signaling.

Glutamatergic neurotransmission is controlled by presynaptic metabotropic glutamate receptors (mGluRs). A subdomain in the intracellular carboxyl-terminal tail of group III mGluRs binds calmodulin and heterotrimeric guanosine triphosphate-binding protein (G protein) betagamma subunits in a mutually exclusive manner. Mutations interfering with calmodulin binding and calmodulin antagonists inhibit G protein-mediated modulation of ionic currents by mGluR 7. Calmodulin antagonists also prevent inhibition of excitatory neurotransmission via presynaptic mGluRs. These results reveal a novel mechanism of presynaptic modulation in which Ca(2+)-calmodulin is required to release G protein betagamma subunits from the C-tail of group III mGluRs in order to mediate glutamatergic autoinhibition.

G protein antagonists.

Heterotrimeric G proteins couple membrane-bound heptahelical receptors to their cellular effector systems (ion channels or enzymes generating a second messenger). In current pharmacotherapy, the input to G protein-regulated signalling is typically manipulated by targeting the receptor with appropriate agonists or antagonists and, to a lesser extent, by altering second messenger levels, most notably by inhibiting phosphodiesterases that hydrolyse cyclic nucleotides. When stimulated, G proteins undergo a cycle of activation and deactivation in which the alpha-subunits and the betagamma-dimers sequentially expose binding sites for their reaction partners (receptors, guanine nucleotides and effectors, as well as regulatory proteins). These domains can be blocked by inhibitors and this produces effects that cannot be achieved by receptor antagonists. Here, the structural and mechanistic information on G protein antagonists is summarized and an outline of the arguments supporting the hypothesis that G proteins per se are also potential drug targets is provided.

Laparoscopic reconstruction of intestinal continuity following Hartmann's procedure.

Laparoscopy-guided reversal of Hartmann's procedure was performed in eleven patients who had been treated surgically for inflammatory disease or cancer of the colon. Restoration of intestinal continuity was achieved in ten of them. There were no postoperative complications. The mean surgical time was 144 minutes and the mean duration of postoperative ileus was 48 hours (range: 30 to 60 hours). The mean hospital stay was 7 days. Our results suggest that laparoscopic reversal of Hartmann's procedure is safer than and as effective as open surgery.