Neutrophil extracellular traps and thrombosis in COVID-19

Journal of Thrombosis and Thrombolysis - Studies of patients with COVID-19 have demonstrated markedly dysregulated coagulation and a high risk of morbid arterial and venous thrombotic events....     

Hantavirus pulmonary syndrome in the United States

Since the first outbreak of hantavirus pulmonary syndrome (HPS) in 1993, understanding of the vast distribution and potential impact of hantaviruses has grown. At least 277 cases of HPS have been documented in the United States. The full clinical spectrum has yet to be elucidated, and one outbreak suggested the possibility of person-to-person transmission. New research has identified the β-3 integrins as cellular receptors for hantaviruses and has determined the pivotal role of the immune system in pathogenesis. Rapid diagnosis has been facilitated by a new immunoblot assay to detect Sin Nombre virus infection. Treatment remains primarily supportive; however, a placebocontrolled trial of ribavirin is ongoing. Extracorporeal membrane oxygenation may be a potential therapy in severe cases; inhaled nitric oxide needs further study. Vaccines developed against hantaviruses associated with hemorrhagic fever and renal syndrome might be effective against HPS-associated strains.     

"You aren't going to get better by just sitting around": physical activity perceptions,motivations, and barriers in adults 75 years of age or older

Despite accumulating evidence of cardiovascular benefits associated with physical activity in older people, sedentary behavior increases with age. Few physical activity research studies focus on underactive adults 75 years and older. In-depth qualitative interviews using open-ended questions explored perceptions, motivations, and barriers to physical activity in 33 previously sedentary or underactive adults age ≥75. Data were analyzed using the NUD*IST (Non-numerical, Unstructured Data Indexing, Searching, and Theorizing) qualitative analysis program. Participants saw sedentary behavior as harmful, considered themselves relatively active, were unsure of amounts of physical activity to do, and welcomed more physical activity information from their doctors. Motivations included health, independence, family, and appearances. Barriers were poor health, lack of time, aging, and adverse environments. Results suggest that people continue to be interested in physical activity as they age, but some misperceptions about physical activity exist. Even with health problems and age, physical activity counseling by doctors is valued and considered helpful by this age group.     

K-RasG12D-induced T-cell lymphoblastic lymphoma/leukemias harbor Notch1 mutations and are sensitive to gamma-secretase inhibitors

To study the impact of oncogenic K-Ras on T-cell leukemia/lymphoma development and progression, we made use of a conditional K-Ras(G12D) murine knockin model, in which oncogenic K-Ras is expressed from its endogenous promoter. Transplantation of whole bone marrow cells that express oncogenic K-Ras into wild-type recipient mice resulted in a highly penetrant, aggressive T-cell leukemia/lymphoma. The lymphoblasts were composed of a CD4/CD8 double-positive population that aberrantly expressed CD44. Thymi of primary donor mice showed reduced cellularity, and immunophenotypic analysis demonstrated a block in differentiation at the double-negative 1 stage. With progression of disease, approximately 50% of mice acquired Notch1 mutations within the PEST domain. Of note, primary lymphoblasts were hypersensitive to gamma-secretase inhibitor treatment, which is known to impair Notch signaling. This inhibition was Notch-specific as assessed by down-regulation of Notch1 target genes and intracellular cleaved Notch. We also observed that the oncogenic K-Ras-induced T-cell disease was responsive to rapamycin and inhibitors of the RAS/MAPK pathway. These data indicate that patients with T-cell leukemia with K-Ras mutations may benefit from therapies that target the NOTCH pathway alone or in combination with inhibition of the PI3K/AKT/MTOR and RAS/MAPK pathways.