Hemangioma cavernoso de mediastino anterior : Presentación de un caso

Los hemangiomas son tumores poco frecuentes dentro de las patologías mediastinales. Debido a sus características macroscópicas (tumores sólidos, infiltrativos, con adherencias a tejidos vecinos) y en estudios por imágenes, suelen ser confundidos con neoplasias malignas. La tomografía computada es el estudio de elección para la evaluación preoperatoria de los mismos, siendo hallazgos frecuentes las calcificaciones (21%). No se aconsejan las biopsias por punción o mediastinoscopía por su alto riesgo de sangrado. Menos de la mitad de los pacientes presentan síntomas al momento del diagnóstico, y cuando existieran, tienen relación con el compromiso y compresión de estructuras vecinas: disnea, tos o dolor torácico son los más frecuentes. En casos sintomáticos o con compromiso de estructuras vitales, la resección quirúrgica es el tratamiento de elección y, la mayoría de las veces, resulta curativa.Facultad de Ciencias Médica

Hemangioma cavernoso de mediastino anterior : Presentación de un caso

Los hemangiomas son tumores poco frecuentes dentro de las patologías mediastinales. Debido a sus características macroscópicas (tumores sólidos, infiltrativos, con adherencias a tejidos vecinos) y en estudios por imágenes, suelen ser confundidos con neoplasias malignas. La tomografía computada es el estudio de elección para la evaluación preoperatoria de los mismos, siendo hallazgos frecuentes las calcificaciones (21%). No se aconsejan las biopsias por punción o mediastinoscopía por su alto riesgo de sangrado. Menos de la mitad de los pacientes presentan síntomas al momento del diagnóstico, y cuando existieran, tienen relación con el compromiso y compresión de estructuras vecinas: disnea, tos o dolor torácico son los más frecuentes. En casos sintomáticos o con compromiso de estructuras vitales, la resección quirúrgica es el tratamiento de elección y, la mayoría de las veces, resulta curativa.Facultad de Ciencias Médica

Hemangioma cavernoso de mediastino anterior : Presentación de un caso

Los hemangiomas son tumores poco frecuentes dentro de las patologías mediastinales. Debido a sus características macroscópicas (tumores sólidos, infiltrativos, con adherencias a tejidos vecinos) y en estudios por imágenes, suelen ser confundidos con neoplasias malignas. La tomografía computada es el estudio de elección para la evaluación preoperatoria de los mismos, siendo hallazgos frecuentes las calcificaciones (21%). No se aconsejan las biopsias por punción o mediastinoscopía por su alto riesgo de sangrado. Menos de la mitad de los pacientes presentan síntomas al momento del diagnóstico, y cuando existieran, tienen relación con el compromiso y compresión de estructuras vecinas: disnea, tos o dolor torácico son los más frecuentes. En casos sintomáticos o con compromiso de estructuras vitales, la resección quirúrgica es el tratamiento de elección y, la mayoría de las veces, resulta curativa.Facultad de Ciencias Médica

HIV-1 Tat protein directly induces mitochondrial membrane permeabilization and inactivates cytochrome c oxidase

The Trans-activator protein (Tat) of human immunodeficiency virus (HIV) is a pleiotropic protein involved in different aspects of AIDS pathogenesis. As a number of viral proteins Tat is suspected to disturb mitochondrial function. We prepared pure synthetic full-length Tat by native chemical ligation (NCL), and Tat peptides, to evaluate their direct effects on isolated mitochondria. Submicromolar doses of synthetic Tat cause a rapid dissipation of the mitochondrial transmembrane potential (ΔΨm) as well as cytochrome c release in mitochondria isolated from mouse liver, heart, and brain. Accordingly, Tat decreases substrate oxidation by mitochondria isolated from these tissues, with oxygen uptake being initially restored by adding cytochrome c. The anion-channel inhibitor 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) protects isolated mitochondria against Tat-induced mitochondrial membrane permeabilization (MMP), whereas ruthenium red, a ryanodine receptor blocker, does not. Pharmacologic inhibitors of the permeability transition pore, Bax/Bak inhibitors, and recombinant Bcl-2 and Bcl-XL proteins do not reduce Tat-induced MMP. We finally observed that Tat inhibits cytochrome c oxidase (COX) activity in disrupted mitochondria isolated from liver, heart, and brain of both mouse and human samples, making it the first described viral protein to be a potential COX inhibitor

HIV-1 Tat Promotes Kaposi's Sarcoma-Associated Herpesvirus (KSHV) vIL-6-Induced Angiogenesis and Tumorigenesis by Regulating PI3K/PTEN/AKT/GSK-3β Signaling Pathway

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is etiologically associated with KS, the most common AIDS-related malignancy. KS is characterized by vast angiogenesis and hyperproliferative spindle cells. We have previously reported that HIV-1 Tat can trigger KSHV reactivation and accelerate Kaposin A-induced tumorigenesis. Here, we explored Tat promotion of KSHV vIL-6-induced angiogenesis and tumorigenesis. Tat promotes vIL-6-induced cell proliferation, cellular transformation, vascular tube formation and VEGF production in culture. Tat enhances vIL-6-induced angiogenesis and tumorigenesis of fibroblasts and human endothelial cells in a chicken chorioallantoic membrane (CAM) model. In an allograft model, Tat promotes vIL-6-induced tumorigenesis and expression of CD31, CD34, SMA, VEGF, b-FGF, and cyclin D1. Mechanistic studies indicated Tat activates PI3K and AKT, and inactivates PTEN and GSK-3β in vIL-6 expressing cells. LY294002, a specific inhibitor of PI3K, effectively impaired Tat's promotion of vIL-6-induced tumorigenesis. Together, these results provide the first evidence that Tat might contribute to KS pathogenesis by synergizing with vIL-6, and identify PI3K/AKT pathway as a potential therapeutic target in AIDS-related KS patients. © 2013 Zhou et al

Septic AKI in ICU patients. diagnosis, pathophysiology, and treatment type, dosing, and timing: a comprehensive review of recent and future developments

Evidence is accumulating showing that septic acute kidney injury (AKI) is different from non-septic AKI. Specifically, a large body of research points to apoptotic processes underlying septic AKI. Unravelling the complex and intertwined apoptotic and immuno-inflammatory pathways at the cellular level will undoubtedly create new and exciting perspectives for the future development (e.g., caspase inhibition) or refinement (specific vasopressor use) of therapeutic strategies. Shock complicating sepsis may cause more AKI but also will render treatment of this condition in an hemodynamically unstable patient more difficult. Expert opinion, along with the aggregated results of two recent large randomized trials, favors continuous renal replacement therapy (CRRT) as preferential treatment for septic AKI (hemodynamically unstable). It is suggested that this approach might decrease the need for subsequent chronic dialysis. Large-scale introduction of citrate as an anticoagulant most likely will change CRRT management in intensive care units (ICU), because it not only significantly increases filter lifespan but also better preserves filter porosity. A possible role of citrate in reducing mortality and morbidity, mainly in surgical ICU patients, remains to be proven. Also, citrate administration in the predilution mode appears to be safe and exempt of relevant side effects, yet still requires rigorous monitoring. Current consensus exists about using a CRRT dose of 25 ml/kg/h in non-septic AKI. However, because patients should not be undertreated, this implies that doses as high as 30 to 35 ml/kg/h must be prescribed to account for eventual treatment interruptions. Awaiting results from large, ongoing trials, 35 ml/kg/h should remain the standard dose in septic AKI, particularly when shock is present. To date, exact timing of CRRT is not well defined. A widely accepted composite definition of timing is needed before an appropriate study challenging this major issue can be launched

The Use of Biomaterials in Islet Transplantation

Pancreatic islet transplantation is a therapeutic option to replace destroyed β cells in autoimmune diabetes. Islets are transplanted into the liver via the portal vein; however, inflammation, the required immunosuppression, and lack of vasculature decrease early islet viability and function. Therefore, the use of accessory therapy and biomaterials to protect islets and improve islet function has definite therapeutic potential. Here we review the application of niche accessory cells and factors, as well as the use of biomaterials as carriers or capsules, for pancreatic islet transplantation

Circulating microparticles: square the circle

Background: The present review summarizes current knowledge about microparticles (MPs) and provides a systematic overview of last 20 years of research on circulating MPs, with particular focus on their clinical relevance. Results: MPs are a heterogeneous population of cell-derived vesicles, with sizes ranging between 50 and 1000 nm. MPs are capable of transferring peptides, proteins, lipid components, microRNA, mRNA, and DNA from one cell to another without direct cell-to-cell contact. Growing evidence suggests that MPs present in peripheral blood and body fluids contribute to the development and progression of cancer, and are of pathophysiological relevance for autoimmune, inflammatory, infectious, cardiovascular, hematological, and other diseases. MPs have large diagnostic potential as biomarkers; however, due to current technological limitations in purification of MPs and an absence of standardized methods of MP detection, challenges remain in validating the potential of MPs as a non-invasive and early diagnostic platform. Conclusions: Improvements in the effective deciphering of MP molecular signatures will be critical not only for diagnostics, but also for the evaluation of treatment regimens and predicting disease outcomes