Cirugía profiláctica en cáncer medular de tiroides hereditario / Prophylactic surgery in hereditary medullary thyroid cancer

Introducción: Se estima que del total de los cánceres, el 5-10% tendría una base genética. Actualmente es posible identificar a los individuos con predisposición genética en algunos cánceres como manera de intervenir precozmente en el desarrollo de esta enfermedad. Objetivos: Evaluar la utilidad de la cirugía profiláctica en el cáncer medular de tiroides hereditario. Material y métodos: Este trabajo es una revisión de literatura de diferentes estudios extraídos de bibliotecas electrónicas como Scientific Electronic Library Online (SciELO), MedLine-PubMed y UpToDate, mediante la construcción de preguntas clínicas y términos MeSH enfocados principalmente en la búsqueda específica de información sobre el cáncer medular de tiroides hereditario. Resultados: Los estudios revisados demuestran que la tiroidectomía profiláctica con resección linfática cervical representa el único tratamiento eficaz en el caso del cáncer medular de tiroides hereditario. Conclusiones: La cirugía profiláctica ha demostrado una importante disminución del riesgo de cáncer de tiroides y se considera una conducta de rigor en portadores del gen RET en el cáncer medular de tiroides.

Introduction: Approximately 5-10% of global cancer has a genetic base. Nowadays it is possible to identify those who have a genetic predisposition for some cancers, so they can be treated in short term. Objectives: Evaluate how useful is prophylactic surgery on hereditary Medullary Thyroid Cancer. Materials and methods: This investigation is a literature review of different research papers from electronic databases such as Scientific Electronic Library Online (SciELO), MedLine-PubMed and UpToDate. The research was made with clinical queries and MeSH terms, specially focused on hereditary Medullary Thyroid Cancer. Results: This research shows that prophylactic Thyroidectomy with cervical lymph node resection is the only effective and curative treatment for hereditary Medullary Thyroid Cancer. Conclusions: Prophylactic surgery has proof an important role decreasing the risk on Hereditary Thyroid cancer Syndrome and in RET carriers surgery is considered a must.

Daño hepático agudo inducido por claritromicina. A propósito de un caso / Acute liver injury induced by clarithromycin, case report

Introducción: El daño hepático por fármacos es una lesión secundaria al uso de medicamentos. Posee una baja incidencia, representando la causa más común de muerte por falla hepática aguda. Es importante el diagnóstico y tratamiento precoz para evitar resultados desfavorables. Presentación del caso: Mujer de 73 años, con antecedentes de Hipertensión arterial en tratamiento, colecistectomizada; cursó neumonía adquirida en la comunidad de presentación atípica en tratamiento con claritromicina 500mg/12 horas y al cuarto día de tratamiento presentó ictericia, coluria, hipocolia y astenia. Al examen físico presentó dolor a palpación en hemiabdomen derecho y hepatomegalia. Los exámenes en urgencias mostraron una marcada alteración de las pruebas hepáticas, con leucocitos de 9.020/mm3 y 8% de eosinófilos. Se solicitó ecotomografía abdominal que no evidenció obstrucción de vía biliar. Durante la hospitalización se descartó serología para Virus Hepatitis A, B, C, Epstein Barr, Citomegalovirus y Virus de la Inmunodeficiancia Humana (VIH), junto con un perfil inmunológico no patológico. Se complementó con colangioresonancia que no evidenció obstrucción de la vía biliar, por lo que se indicó biopsia hepática que concluyó "daño hepático secundario a fármacos''. Se suspendió claritromicina, evolucionando favorablemente dándose de alta al séptimo día. Discusión: La claritromicina es un antibiótico usado ampliamente para tratar las infecciones bacterianas, sin embargo, es capaz de inducir daño hepático. El diagnóstico del daño hepático por fármacos es difícil, requiriéndose alto índice de sospecha, en donde las manifestaciones clínicas, la eosinofilia y el descarte de otras patologías son fundamentales para plantear el diagnóstico.

Introduction: Drug induced liver injury (DILI), is a drug hepatotoxicity, with low incidence. However represents the most common cause of death secondary to acute liver failure. Assertive diagnosis and early treatment is important to avoid adverse results. Case report: A 73-year-old woman, with arterial hypertension and cholecystectomy, who suffered community acquired pneumonia with atypical presentation, was treated with clarithromycin 500 mg twice a day. She manifested jaundice, choluria, hipocholia and fatigue after the fourth day in treatment. Additional, physical examination: at palpation showed right and upper abdominal pain, and hepatomegaly. During the emergency room, laboratory tests showed significant alterations in liver function. Total leukocyte count 9020 with 8% eosinophils. Abdominal ultrasound was negative for biliary obstruction. During hospitalization, markers for autoimmune liver disease were non pathological, and viral serologies (Hepatitis A, B, C viruses, Epstein Barr, Cytomegalovirus and Human immunodeficiency virus) were negative. Biliary obstruction was negative according Magnetic resonance cholangiopancreatography. Liver biopsy showed "drug induced liver injury". Clarithromycin was suspended, and the patient achieved clinical improvement and she was discharge at the 7th day. Discussion: Clarithromycin is an antibiotic widely used for several bacterial infections, capable of induced hepatotoxicity. Diagnosis of DILI is difficult, that requires high index of clinical suspicion. Clinical manifestations, eosinophilia and diferential diagnoses are key for an assertive diagnosis

Effects of 7-O-demethylisothalicberine, a bisbenzylisoquinoline alkaloid of Berberis chilensis, on electrical activity of frog cardiac pacemaker cells.

1. In spontaneously beating preparations of sinus venosus of the chilean frog Caudiverbera caudiverbera, the electrophysiological effects of 7-O-demethylisothalicberine (7-O-DI) on transitional pacemaker cells were investigated. 2. 7-O-DI in concentration 1 x 10(-4) M blocked the action potential of transitional cells. This blockade was preceded by subthreshold oscillations and depolarization of membrane potential. 3. Lower concentration of the drug to induce complete blockade (5 x 10(-5) M), allowed to observe a great depression of bioelectric cell characteristics in transitional fibres. 4. 7-O-DI induced blockade of transitional cells action potential was preceded by the appearance of a notch in their upstroke and the persistence of a fast depolarizing activity that remained unblocked. This 7-O-DI resistant fast component of the upstroke was blocked by tetrodotoxin. 5. Transitional cells completely blocked by 7-O-DI were depolarized to about 40 mV. 6. The results indicate a close similarity between 7-O-DI and verapamil effects on action potential configuration.