Development of a Fluorescent Assay to Search New Drugs Using Stable tdTomato-Leishmania, and the Selection of Galangin as a Candidate With Anti-Leishmanial Activity.

Antimonials continue to be considered the first-line treatment for leishmaniases, but its use entails a wide range of side effects and serious reactions. The search of new drugs requires the development of methods more sensitive and faster than the conventional ones. We developed and validated a fluorescence assay based in the expression of tdTomato protein by Leishmania, and we applied this method to evaluate the activity in vitro of flavonoids and reference drugs. The pIR1SAT/tdTomato was constructed and integrated into the genome of Leishmania (Leishmania) amazonensis. Parasites were selected with nourseothricin (NTC). The relation of L. amaz/tc3 fluorescence and the number of parasites was determined; then the growth in vitro and infectivity in BALB/c mice was characterized. To validate the fluorescence assay, the efficacy of miltefosine and meglumine antimoniate was compared with the conventional methods. After that, the method was used to assess in vitro the activity of flavonoids; and the mechanism of action of the most active compound was evaluated by transmission electron microscopy and ELISA. A linear correlation was observed between the emission of fluorescence of L. amaz/tc3 and the number of parasites (r2 = 0.98), and the fluorescence was stable in the absence of NTC. No differences were observed in terms of infectivity between L. amaz/tc3 and wild strain. The efficacy of miltefosine and meglumine antimoniate determined by the fluorescence assay and the microscopic test showed no differences, however, in vivo the fluorescence assay was more sensitive than limiting dilution assay. Screening assay revealed that the flavonoid galangin (GAL) was the most active compound with IC50 values of 53.09 µM and 20.59 µM in promastigotes and intracellular amastigotes, respectively. Furthermore, GAL induced mitochondrial swelling, lipid inclusion bodies and vacuolization in promastigotes; and up-modulated the production of IL-12 p70 in infected macrophages. The fluorescence assay is a useful tool to assess the anti-leishmanial activity of new compounds. However, the assay has some limitations in the macrophage-amastigote model that might be related with an interfere of flavanol aglycones with the fluorescence readout of tdTomato. Finally, GAL is a promising candidate for the development of new treatment against the leishmaniasis.

Pathologic features and clinical course of a non-functioning primary pulmonary paraganglioma: A case report.

INTRODUCTION: Paragangliomas (PGGL) are rare neuroendocrine tumors arising from non-epithelial extra-adrenal chromaffin cells. They have been described in different sites: abdomen, pelvis, head, neck and thorax. Incidence is very low, occurring in less than 2-8/million per year. PGGL's of the lung are extremely rare, they have a slow growth and present as painless lesions. Biopsy is the method of choice for diagnosis and prognosis. PRESENTATION OF CASE: This is a 70-year-old woman with chronic cough, with a CT-scan showing a 3.3-cm mass in the left lower lobe. After video-assisted thoracic surgery, histologic findings confirmed a non-functioning pulmonary paraganglioma. We present the clinical, radiological, pathological findings and clinical course. DISCUSSION: Primary pulmonary PGGL's are extremely rare neuroendocrine tumors with low-grade malignancy, difficult to distinguish from other pulmonary tumors relying only on imaging techniques. In this case, PGGL presented as an incidentaloma during the evaluation of chronic cough. After histological diagnosis, genetic testing are ideally performed to identify somatic or germline mutations that may condition a higher risk of malignancy and metastasis. CONCLUSION: PGGL's must be considered when other diagnoses are unlikely due to immunohistochemistry findings. Larger studies in this field are needed to determine the risk factors for its development and to determine which populations have the greatest potential for malignant transformation.

Giant Intrathoracic Goiter of Atypical Presentation: A Case Report.

BACKGROUND: The term goiter is used to describe any abnormal growth of the thyroid gland, which can be diffuse or nodular, and can be associated with normal, diminished, or increased thyroid function. Multinodular goiter is a common disease whose prevalence increases at age 50. Clinical manifestations can be due to thyroid function impairment or related to size and location of the gland with compressive symptoms. Intrathoracic location is less frequent, can be mistaken with pulmonary lesions and usually implies a difficult surgical approach. CASE PRESENTATION: A 66-year-old woman with a history of subtotal thyroidectomy presented with 7-month dyspnea, dry cough. There was no evidence of neck masses, or jugular engorgement. Physical examination was normal. Chest x-ray showed an 11 cm mass in the upper right hemithorax. Computed tomography (CT)-scan, showed calcifications, and compression of the superior vena cava without infiltration, the right subclavian vein and left displacement of the trachea. Distinction between intrapulmonary or mediastinal location was not clear. Biopsy showed thyroid origin, and bilateral thoracotomy was performed with confirmation of a giant multinodular goiter. CONCLUSIONS: Intrathoracic goiter should undergo surgical or ablative management if compressive symptoms of the airway and cervical or thoracic vessels are present. The large size of the tumor along with the presentation after thyroidectomy and the seeming location in the right upper lobe made this particular case striking. Specially in the elderly, multidisciplinary perioperative management is key for a successful recovery.

Clinical and Mutational Aspects of Non-small Cell Lung Cancer in a Latin American Reference Center / Aspectos clínicos y mutacionales del cáncer de pulmón de célula no pequeña en un Centro de Referencia de Latinoamerica

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