More than a Feeling: Dermatological Changes Impacted by Spaceflight

Spaceflight poses a unique set of challenges to humans and the hostile Spaceflight environment can induce a wide range of increased health risks, including dermatological issues. The biology driving the frequency of skin issues in astronauts is currently not well understood. To address this issue, we used a systems biology approach utilizing NASA's Open Science Data Repository (OSDR) on spaceflown murine transcriptomic datasets focused on the skin, biomedical profiles from fifty NASA astronauts, and confirmation via transcriptomic data from JAXA astronauts, the NASA Twins Study, and the first civilian commercial mission, Inspiration4. Key biological changes related to skin health, DNA damage & repair, and mitochondrial dysregulation were determined to be involved with skin health risks during Spaceflight. Additionally, a machine learning model was utilized to determine key genes driving Spaceflight response in the skin. These results can be used for determining potential countermeasures to mitigate Spaceflight damage to the skin.

Accuracy of precordial percussion in detecting cardiomegaly

STUDY OBJECTIVE

To assess the value of precordial percussion in detecting cardiomegaly, and to compare it with palpation of the apical impulse.

DESIGN

Descriptive study.

SETTING

Hospitals and clinics of a university medical center.

PATIENTS

Light indirect percussion of the precordium was performed on 72 inpatients and 28 outpatients. All patients had a posteroanterior radiograph of the chest. Percussors were unaware of the clinical history and of chest roentgenogram results.

MEASUREMENTS AND MAIN RESULTS

Thirty-six patients (36%) had cardiomegaly, defined as a cardiothoracic ratio of greater than 0.5 on chest roentgenogram. The cardiothoracic ratio was significantly correlated with percussion distance from the midsternal line in the left fourth (r = 0.35, p less than 0.0006), fifth (r = 0.65, p less than 0.00001), and sixth (r = 0.40, p less than 0.0001) intercostal spaces. After adjustment for clinical symptoms and systolic and diastolic blood pressures, percussion distance in the left fifth intercostal space remained a significant independent predictor of the cardiothoracic ratio. Percussion distance in the left fifth interspace discriminated cardiomegaly with a receiver-operating characteristic (ROC) area of 0.95. Percussion dullness more than 10.5 cm from the midsternal line in the left fifth interspace had a sensitivity of 94.4% (95% confidence interval [CI], 79.9% to 99.0%) and a specificity of 67.2% (CI, 54.2% to 78.1%). Distance of the apical impulse from the midsternal line discriminated with an ROC area of 0.95, but an impulse was palpated in only 40% of cases.

CONCLUSIONS

Percussion in the left fifth intercostal space accurately discriminates patients with and without cardiomegaly, and adds information beyond that obtainable from the history and other parts of the physical examination.