Carcinoma papilar tiroideo con invasión locorregional: reporte de caso / Papillary thyroid crcinoma with locoregional invasion: case report

El cáncer diferenciado de tiroides incluye el tipo papilar y folicular que representan más del 80% de los casos y tienen un excelente pronóstico. Existen varios subtipos histológicos y las variantes foliculares son probablemente las más comunes. La incidencia de cáncer papilar variante folicular ha ido en aumento. En un reporte de un solo centro, cerca del 40% de los cánceres papilares eran variantes foliculares1. El subtipo infiltrativo de la variante folicular presenta sectores que invaden el parénquima tiroideo no neoplásico y carece de una cápsula tumoral bien definida. Tiene un comportamiento biológico y un perfil molecular que es más similar al tumor papilar clásico2. Existen características clínicas y patológicas asociadas con riesgo más alto de recurrencia tumoral y mortalidad; entre ellos se describen el tamaño del tumor primario y la presencia de invasión de tejidos blandos3. En la invasión de estructuras adyacentes, los sitios más comprometidos incluyen los músculos pretiroideos, el nervio laríngeo recurrente, el esófago, la faringe, laringe y la tráquea. Además, puede haber otras estructuras involucradas como: la vena yugular interna, la arteria carótida y los nervios vago, frénico y espinal4. El compromiso de los ganglios linfáticos y la incidencia de metástasis ganglionares en adultos depende de la extensión de la cirugía. Entre los que se realizan una disección radical modificada del cuello, hasta el 80% tienen metástasis en los ganglios linfáticos y el 50% de ellas son microscópicas5. Clínicamente los tumores localmente avanzados cursan con disfonía, disfagia, disnea, tos o hemoptisis, pero la ausencia de síntomas no descarta la invasión local. Según las guías de la American Thyroid Association6 son variables de mal pronóstico: la edad del paciente, el tamaño del tumor primario, la extensión extra tiroidea y la resección quirúrgica incompleta.

Differentiated thyroid cancer includes papillary and follicular types that represent more than 80% of cases and have an excellent prognosis. There are several histologic subtypes, and follicular variants are probably the most common. The incidence of papillary follicular variant cancer has been increasing. In a singlecenter report, about 40% of papillary cancers were follicular variants1. The infiltrative subtype of the follicular variant presents sectors that invade the non-neoplastic thyroid parenchyma and lacks a well-defined tumor capsule. It has a biological behavior and a molecular profile that is more similar to the classic papillary tumor2. There are clinical and pathological characteristics associated with a higher risk of tumor recurrence and mortality; These include the size of the primary tumor and the presence of soft tissue invasion3. In the invasion of adjacent structures, the most compromised sites include the pre-thyroid muscles, the recurrent laryngeal nerve, the esophagus, the pharynx, larynx and trachea. In addition, there may be other structures involved such as: the internal jugular vein, the carotid artery and the vagus, phrenic and spinal nerves4. The involvement of the lymph nodes and the incidence of lymph node metastases in adults depends on the extent of the surgery. Among those who undergo a modified radical neck dissection, up to 80% have lymph node metastases and 50% of them are microscopic5. Clinically locally advanced tumors present with dysphonia, dysphagia, dyspnea, cough, or hemoptysis, but the absence of symptoms does not rule out local invasion. According to the American Thyroid Association guidelines6, there are variables with a poor prognosis: the age of the patient, the size of the primary tumor, the extra-thyroid extension, and incomplete surgical resection.

Variante células altas de cáncer papilar de tiroides: reporte de casos / Tall cell variant of papillary thyroid cancer: case report

El cáncer papilar constituye aproximadamente el 80% de todos los casos de cáncer de tiroides y el 85% de los tumores diferenciados. La variante de células altas representa el 1,3 al 12% del cáncer papilar siendo la variante agresiva más común de estos tumores. Posee un comportamiento agresivo, con mayor incidencia de invasión extratiroidea, linfovascular y metástasis a distancia, responsables de tasas de recurrencia más altas y peor pronóstico. Los casos aquí reportados reflejan las características que hacen sospechar mayor agresividad tumoral, desde el diagnóstico. Describimos dos pacientes de sexo femenino, entre 40 y 50 años, con historia de corta evolución, cuya presentación fue con síntomas de compresión locorregional y adenopatías metastásicas en cuello. Con hallazgos ecográficos e intraoperatorios de relevancia en cuanto la agresividad tumoral que hicieron sospechar la presencia de una variante agresiva del cáncer papilar. La histopatología de la variante de células altas posee una base molecular diferente respecto al papilar clásico que le confiere mayor morbi-mortalidad, constituyendo un factor de pronóstico independiente para la recurrencia. El tratamiento quirúrgico es la tiroidectomía total con vaciamiento profiláctico de los ganglios linfáticos centrales y eventualmente vaciamiento lateral de cuello según valoración preoperatoria, con posterior ablación postoperatoria de restos tiroideos mediante yodo radiactivo.

Papillary cancer constitutes approximately 80% of all thyroid cancer cases and 85% of differentiated tumors. The tall cell variant represents 1.3 to 12% of papillary cancers, being the most common aggressive variant of these tumors. It has an aggressive behavior, showing a higher incidence of extrathyroid and lymphovascular invasion and distant metastasis, responsible for higher recurrence rates and a worse prognosis. The cases reported here reflect characteristics that make us suspect tumor aggressiveness. These are female patients, between 40 and 70 years old, with a history of short evolution. They present locoregional symptoms or metastatic adenopathies, with ultrasound and intraoperative findings of relevance in terms of tumor aggressiveness that led to the suspicion of the presence of an aggressive variant of papillary cancer. The histopathology of the tall cell variant has a different molecular basis that confers its own morbidity and mortality, being an independent prognostic factor for recurrence. Total thyroidectomy is recommended with prophylactic dissection of the central lymph nodes and eventually lateral neck dissection according to preoperative evaluation followed by postoperative ablation with radioactive iodine.

Trastornos del sueño en los pacientes críticos / Sleep disorders in critically ill patients

Sleep disorders are common in critically ill patients, and its consequences still insufficiently clarified. An environment with multiple noxious stimuli, light and hearing, admission for severe acute illness with multisystem disease, and the need for drugs that can disrupt sleep physiology, lead to this situation. We will review the epidemiology and risk factors for these disorders, and its possible consequences. Finally we discuss potential strategies for prevention of sleep disorders in this patient population.

Estrés oxidativo en el trastorno afectivo bipolar / Oxidative stress in bipolar disorder

The pathogenesis of psychiatric disorders have not been fully unravelled. Several theories have been proposed, from those focused on psychosocial aspects to those with a biological basis. Mood disorders are a group of psychiatric disorders with a chronic and recurrent fashion. Therefore these disorders could have molecular etiological basis prompted to be described and typified and currently there is a growing interest to unravel the role of oxidative damage in bipolar disorder and how it could be compensated by the enzymatic antioxidant system. The assessment of both oxidative damage and antioxidant enzyme system s allow us propose some theories that might explain a possible etiologic origin of this disease. Nevertheless, no consensus exists about this proposal. Published studies how an increased oxidative damage in cells from bipolar cases. It produces lipid and protein alterations that could potentially lead to DNA damage, and therefore their repair mechanisms.

La etiopatogenia de los diferentes trastornos psiquiátricos no está completamente dilucidada, se han propuesto diversas teorías que se basan en múltiples enfoques que van desde aquellos centrados en aspectos psicosociales hasta los netamente biologicistas. Los trastornos del ánimo no han estado ajenos a estos estudios, entre ellos el trastorno bipolar se muestra cómo uno de los cuadros que por su carácter crónico y recurrente podría tener su génesis a nivel de alteraciones moleculares posibles de ser definidas y tipificadas. En el último tiempo se ha prestado una importancia creciente a la determinación del rol del daño oxidativo en el trastorno bipolar y de cómo dichas alteraciones generan cambios compensatorios en los sistemas enzimáticos antioxidantes. Su cuantificación ha permitido formular algunas teorías para explicar un posible origen de éste cuadro, sin embargo, hasta la fecha aun no existe un consenso al respecto. Los estudios existentes demuestran categóricamente que existe en pacientes bipolares hay un claro aumento del daño oxidativo, provocando alteración en lípidos y proteínas, que pueden llevar potencialmente a una alteración sobre el ADN y sus mecanismos de reparación.

Adenitis mesentérica por Yersinia enterocolítica / Mesenteric adenitis due to Yersinia enterocolitic

Se presenta por primera vez en nuestro país un caso de adenitis mesentérica en una niña de 3 años asociado a infección por Yersinia enterocolítica. La cepa recuperada del coprocultivo correspondió al bioserotipo patogénico 4/O:3 y presentó además el plásmido de virulencia.

Comparación farmacocinética de Sinemet y Grifoparkin (levodopa/carbidopa 250/25 mg) en pacientes con enfermedad de Parkinson avanzada: un estudio con dosis única / Pharmacokinetic comparison of Sinemet and Grifoparkin (levodopa/carbidopa 250/25 mg) in Parkinson s disease: a single dose study

BACKGROUND: There are doubts wether generic medications have the same bioavailability and efficacy compared with the original drugs developed by pharmaceutical companies with research capabilities. AIM: To compare the pharmacokinetics and clinical (motor) responses of Sinemet and Grifoparkin (generic carbidopa/levodopa 250/25 mg) in patients with advanced Parkinson's disease. PATIENTS AND METHODS: Patients were randomly assigned to Sinemet (15 patients 62 +/- 12 years old; mean disease duration 11 +/- 7 years) or Grifoparkin (15 patients, 64 +/- 11 years old; mean disease duration 12 +/- 4 years) groups. Medication and food were withheld 12 h before the study. Fifteen blood samples were collected (starting 9 AM) immediately before (sample 1, t = 0 min) and after (samples 2-15, t = 20-360 min) oral administration of a single dose of Sinemet or Grifoparkin, and plasmatic L-DOPA was quantified using HPLC with electrochemical detection. Additionally, each patient was clinically evaluated every 20 minutes, using the tapping test and the unified Parkinson's disease scale Hoehn & Yarh. RESULTS: Tmax (time at which the maximal L-DOPA concentration was reached) were 69 +/- 12 min and 64 +/- 11 min for Sinemet and Grifoparkin respectively (NS). Cmax (maximal L-DOPA concentration reached) was 3161 +/- 345 ng/ml for Sinemet and 3274 +/- 520 ng/ml for Grifoparkin (NS). The t1/2 (half life time), CL (clearance) and volume of distribution (Vd) values calculated were 159 +/- 32 min, 51.7 +/- 5.1 1/h and 3.6 +/- 1.2 l/kg for Sinemet and 161 +/- 48 min, 58.7 +/- 8 l/h and 3.0 +/- 0.7 l/kg for Grifoparkin (NS). UPDRS-III value for the best on state and for the worst off state were 23 +/- 11 and 50 +/- 19 for Sinemet and 20 +/- 7 and 46 +/- 13 for Grifoparkin respectively (NS). CONCLUSION: The results obtained showed that both drugs are bioequivalent in patients with advanced Parkinson's disease.

A brain microdialysis study on 5-HT release in freely moving rat lines selectively bred for differential 5-HT1A receptor function

Breeding for high and low hypothermic responses to systemic administration of a serotonin1A (5-HT1A) receptor agonist (8-hydroxy-2-(di-n-propylamino)tetralin, 8-OH-DPAT) has resulted in high DPAT-sensitive (HDS) and low DPAT-sensitive (LDS) lines of rats, respectively. These lines also differ in several behavioral measures associated with stress. In the present microdialysis study we observed that basal 5-HT concentrations in the prefrontal cortex and dorsal hippocampus did not differ significantly between HDS and LDS rats. Thus, behavioral differences between the HDS and LDS lines might not be attributed to differences in basal 5-HT release. However, both lines had lower basal levels of 5-HT release than their randomly bred control group (random DPAT-sensitive, RDS) in the prefrontal cortex (mean ± SEM, pg/20 æl, was 3.0 ± 0.4 for LDS, 3.8 ± 0.3 for HDS and 6.4 ± 0.6 for RDS; F(2,59) = 5.8, P<0.005). The administration of (±)-fenfluramine (10 mg/kg) induced a greater increase in hippocampal 5-HT levels in HDS rats (500 percent) as compared with LDS (248 percent) or RDS (243 percent) rats (P<0.0001). There were no significant differences in the prefrontal cortex among lines, with a fenfluramine-induced 5-HT increase of about 900 percent in the three groups. This differential response to fenfluramine may be due to functional alterations of hippocampal 5-HT reuptake sites in the HDS line