Melanocitoma meníngeo del ángulo pontocerebeloso: claves imagenológicas para su abordaje / Cerebellopontine meningeal melanocytoma: keys for imaging diagnostic approach

Resumen: Las lesiones del ángulo pontocerebeloso (APC) representan el 6 al 10% de las neoplasias intracraneales, siendo los schwannomas vestibulares y meningiomas los más comunes. Sin embargo, hasta el 15% pueden ser otras lesiones, entre ellas las derivadas a partir de restos de células melanocíticas presentes en las leptomeninges. El diagnóstico diferencial de las patologías tumorales del APC es extenso, siempre teniendo en cuenta las lesiones más comunes. Sin embargo, cuando las características radiológicas no son las esperadas, el enfoque debe orientarse hacia las lesiones inusuales, poniendo en contexto las diferentes estirpes celulares que pueden dar origen a las neoplasias en esta localización, como las neoplasias melanocíticas. Se presenta el caso de un masculino de 74 años con síndrome cerebeloso de tórpida evolución, al cual se le realiza RM de cerebro contrastada, identificando una lesión de base dural en el APC izquierdo, con hiperintensidad de señal en T1 e hipointensidad en T2, atípico para las lesiones más comunes en esta región, que sugiere su contenido melanocítico.

Abstract: Cerebellopontine angle tumors (CPA) represent approximately 6 to 10% of intracranial tumors. Vestibular Schwannomas and meningiomas are the most common, however up to 15% can be of other origin, including from melanocytes derived from the neural crest. The differential diagnosis of CPA pathologies is extensive, always taking into account the most common ones. However, if the radiological characteristics are not the expected, the approach should be directed towards unusual lesions, putting into context the different cell lines that can give rise to the neoplasm at this location, such as melanotic neoplasms. We present a case of a 74-year-old male, who presented with a cerebellar syndrome. Due to an atypical clinical evolution, a contrast enhanced head MRI was performed, revealing a dural based tumor on the left CPA, which was hyperintense on T1 and hypointense on T2 weighted sequences, which is not expected from the common lesions at this region and suggested it's melanotic content.

Utilidad del índice de presión arterial tobillo-tobillo en pacientes con trauma en extremidad inferior y signos blandos de lesión vascular / Significance and utility of the ankle-ankle systolic pressure index in inferior limb trauma patients and soft signs of vascular injury

Objetivos: Establecer la utilidad del índice de presión arterial tobillo-tobillo (ITT) en los pacientes con trauma de extremidades inferiores y signos blandos de lesión vascular en términos de sensibilidad, especificidad y valores predictivos según el mejor punto de corte detectado. Material y método: Se incluyeron 120 pacientes con trauma en extremidades inferiores y signos blandos de lesión vascular que ingresaron al Hospital Universitario de Santander (Bucaramanga, Colombia) durante los años 2012 a 2015, a los cuales se les calculó el índice tobillo-brazo (ITB) e ITT. Resultados: Un total de 21 (17,5%) pacientes tuvieron ITB menor a 0,9 al ingreso, los cuales fueron llevados a intervención quirúrgica inmediata, encontrando lesión vascular; 2 (1,6%) pacientes tuvieron ITB menor a 0,9 en el control realizado a las 6 h, los cuales también fueron llevados a intervención quirúrgica, encontrando lesión vascular. Por tanto, se encontraron 23 pacientes con lesión vascular. Las curvas ROC tanto de ITB como de ITT señalan que ambas tienen un muy buen desempeño para diagnosticar las lesiones vasculares en pacientes con signos blandos cuando se emplean una única vez. En ambos casos, el punto de corte propuesto tradicionalmente de 0,90 tiene una capacidad discriminatoria adecuada, con sensibilidad de 91% (IC 95%: 0,71-0,98), especificidad de 100% (IC 95%: 0,96-1,0), valor predictivo positivo de 100% (IC 95%: 0,83-1,0) y valor predictivo negativo de 97% (IC 95%: 0,92-0,99). Conclusión. El índice tobillo-tobillo (ITT) permite descartar lesión vascular en el paciente con trauma en extremidades inferiores y signos blandos.

Objectives: We pretend to establish the utility of the ankle-ankle systolic pressure index (AAI) in patients with trauma in the inferior limbs and soft signs of vascular injury describing its sensitivity, specificity and predictive values according to the best cut-off point. Material and method: The cohort included 120 patients with trauma in the inferior limbs and soft signs of vascular injury who attended the University Hospital of Santander (Bucaramanga, Colombia) over a period of 4 years (2012-2015). Results: 21 (17.5%) patients had an ankle brachial pressure index (ABI) < .9 at the admission and they received immediately surgical management, finding vascular injury in the operating room; 2 (1.6%) patients had an ABI < .9 in the 6 h monitoring control and they also received surgical management finding vascular injury. Therefore, we found 23 patients with vascular injury. The ROC curves for the ABI and AAI show that they both have a good achievement for the diagnosis of vascular injury in patients with soft signs when they were used one time. In both cases, the traditionally point of .90 has a good discriminatory capacity with a sensitivity of 91% (95% CI: .71-.98), specificity of 100% (95% CI: .96-1.0), positive predictive value of 100% (95% CI: .83-1.0) and negative predictive value of 97% (95% CI: .92-.99). Conclusion. The ankle-ankle systolic pressure index (AAI) allows to rule out vascular injury in the patient with trauma in the inferior limbs and soft signs.

Moluscos asociados a las raices sumergidas del mangle rojo Rhizophora mangle, en el Golfo de Santa Fe, Estado Sucre, Venezuela / Mollusks associated to the submerged roots of the red mangrove, Rhizophora mangle (L. ), in the Gulf of Santa Fe, Sucre State, Venezuela

A qualitative and quantitative monthly study of the mollusks community associated to the submerged roots of the red mangrove, Rhizophora mangle (L.), between October of 1998 and September of 1999, in six stations of the Gulf of Santa Fe, (Sucre State, Venezuela). Were collected 4,704 specimens, 45 species of mollusks were identified (22 gastropods, 15 bivalves and 8 chitons). The most abundant species were: Crassostrea rhizophorae, Isognomon bicolar, I. alatus and Brachidontes exustus. The highest values in diversity and evenness, and the smallest dominant values, were in the stations three and four, while the opposed happened in the stations one and two. The analysis of likeness showed that in the first five stations the space variations in the composition of the community are bigger than the temporary variations, while in the station six the temporary differences prevail. They were factors that could be important to determine the structure of the community, as vicinity to other ecosystems and/or specific biological aspects of the species like adaptations to fluctuating conditions, nutritious habits and migration in search of shady and protected atmospheres

Disponibilidad de juveniles por captación natural de la ostra Pteria colymbus (Bivalvia: Pteriidae) en el Golfo de Cariaco, Venezuela / Availabilty of juveniles from natural sources of the Pteria colymbus oyster (Bivalvia: Mytilidae), in the Gulf of Cariaco, Venezuela

We examined the spat availability the oyster Pteria colymbus at 6-8 and 19-21 m depths for 15 months (March 1993-June 1994) in Turpialito, Golfo de Cariaco, Venezuela. Spats were trapped using artificial collectors (plastic filaments in bags, 30 x 60 mm), suspended from a long line. Each collector was replaced by a replica monthly to analyse abundance, shell dimension and mass of P. colymbus. Intraweekly, the temperature, salinity, oxygen and food availability (Chlorophyll a, total seston, organic and inorganic seston) were determinated. There is juvenile recruitment all year, suggesting continuous reproduction. Spat counts were higher at 6-8 m (generally 50-230 juveniles per collector) with peaks in August and December 1993 (April and June 93 at 19-21 m). The length-weigh mass relation was higher at 19-21 m, suggesting greater food availability because of lower organism density (including P. colymbus) and a greater water flux. Phytoplanktonic abundance and temperature were correlated (r2=0.38) with juvenile abundanc; this relationship and the association of juvenile abundance with higher temperature and Chlorophyll a levels, suggest that spat abundance was higher at the beginning of the water stratification period, when phytoplankton biomass is high.

Gastritis hipertrófica gigante (enfermedad de Menetrier) y cáncer de colon: asociación casual? / Hypertrophic gastritis large (Menetrier's disease) and colon cancer: casual association?

La gastritis hipertrófica gigante o enfermedad de Menetrier es una patología caracterizada por la presencia de plieges largos y gruesos de aspectos cerebriforme que envuelven parte o la totalidad del estómago. Los pacientes frecuentemente tienen síntomas del tracto gastrointestinal, pérdida de peso y edema por hipoproteinemia. Los estudios radiológicos y de laboratorio son claramente diagnósticos. Su degeneración maligna, así como su asociación con otras neoplasias del tubo digestivo, debe ser motivo de alarma e investigación. Se presenta un caso y se hace revisión de la literatura