Serum vitamin D levels and the severity and clinical course of COVID-19.

Low vitamin D levels are associated with different pulmonary diseases, such as chronic obstructive pulmonary disease, bronchial asthma, and obstructive sleep apnea. In this study, we aimed to assess the relation between vitamin D levels and COVID-19 severity. Positive COVID-19 patients were subjected to clinical examination, computed tomography of the chest, and laboratory investigations.

Transbronchial lymph node forceps biopsy as a novel tool in diagnosis of mediastinal lymphadenopathy: a pilot study.

Background: Differential diagnosis of mediastinal lymphadenopathy is an issue of debate. Lymph nodes may be enlarged due to a variety of inflammatory, infectious, or malignant reasons. Therefore, obtaining samples from the affected nodes is crucial for the diagnosis.