Clinical Research Directory

Human Milk Oligosaccharides (HMOs) and Gut Microbiota, Immune System in Antarctica

Human milk oligosaccharides (HMOs) are the third-most abundant component in mothers' milk and are an important prebiotic factor for the development of the gut microbiota of infants, promoting the growth of certain beneficial bacterial strains and providing protection against many bacterial and viral infections. HMOs induce immunomodulatory activity by affecting immune cell populations and functions. In a simulator of the adult human intestinal microbial ecosystem, fermentation of HMOs led to an increase of bifidobacteria in parallel with an increase in short-chain fatty acids as well as a reduction in inflammation markers, supporting the potential of HMOs to provide health benefits also in adults. Long-term stay in microgravity induces many physiological responses, including diminished immune function and impaired glucose tolerance which may lead to rather severe consequences. Similarly, hypoxia conditions as in the Concordia station, affects the immune system and may lead to impaired glucose tolerance and insulin resistance. The hypothesis is that HMOs as a prebiotic supplement will mitigate changes in immune function, glucose tolerance, lipid homeostasis, and neurotransmitter production. It is expected that HMO supplementation will * Modulate gut microbiota composition and function * Improve inflammation status * Improve immune function * Improve glucose tolerance * Improve nutritional status * Prevent changes in neurotransmitters associated with anxiety and depression. During the stay in Antarctica an HMO blend will be supplemented to the verum group of volunteers. The control group will receive a placebo. Experiment days with blood drawing, an oral glucose tolerance test, saliva sampling, and feces samples are planned once before, about every second month in Concordia, and once after return.

Evaluation of Membrane Lung Function in High-altitude Regions

Over the last 20 years, extracorporeal membrane oxygenation (ECMO) has been used to support adult patients with respiratory or cardiac failure who are unlikely to survive conventional treatment methods. ECMO circuit, pump, and oxygenator technology improvements permit safer perfusion for extended periods. The prolonged use of an ECMO circuit increases the risk of membrane lung (ML) dysfunction. The ML is responsible for taking in oxygen and removing carbon dioxide. The non-biologic surface of the ML triggers inflammatory and coagulation pathways, resulting in the formation of blood clots, breakdown of fibrin, and activation of white blood cells, which ultimately leads to ML dysfunction. Coagulation and fibrinolysis activation can cause systemic coagulopathy or hemolysis, and the deposition of blood clots can block blood flow. Moreover, the accumulation of moisture in the gas phase and the buildup of protein and cellular debris in the blood phase may contribute to shunt and dead-space physiology, respectively, impairing the exchange of gases. These three categories-hematologic abnormalities, mechanical obstruction, and inadequate gas exchange-account for most ML exchanges. Worsening oxygenation during ECMO should prompt quantification of oxygen transfer. ML exchange is indicated when the ML can no longer meet the patient's oxygen demand. The partial pressure of Post-ML arterial oxygen less than 200 mmHg is the most important consideration in this decision. In some high-altitude regions of China, ECMO treatment is also routinely conducted. The experiences above are derived from low-altitude areas, and whether they apply in high-altitude regions is still being determined. This study aimed to explore the significantly lower membrane lung oxygen uptake in high-altitude regions compared to low-altitude areas.

HighCycle: Effect of Acetazolamide on Pulmonary Artery Pressure in Women Compared to Men

Randomized clinical trial evaluating the effect of acetazolamide on pulmonary artery pressure in women compared to men travelling to 3600 m.

The Study of Personalized Health Check-up Programs and Standards for High-altitude Migrant Populations

By using wearable devices to monitor and record the physiological data changes and health outcomes (incidence and severity of high-altitude illnesses) of high-altitude migrants at different stages (pre-entry, acute/chronic high-altitude phases, and de-acclimatization phase), and referencing previous cohort studies on high-altitude populations, the study aims to provide a basis for developing personalized health assessment protocols for high-altitude migrants. The formulated assessment protocols and standards will then be validated.

The Effect of Acute High Altitude Exposure on Rescuer Performance and Patient Care

Rescue services in mountainous regions are frequently called to missions at altitudes \>3000 m. Under the difficult conditions of acute exposure to altitude, the crews then have to undertake demanding medical and rescue measures. Previous studies in non-medical personnel, such as astronauts, aircraft pilots, and military helicopter pilots have found that the lack of oxygen associated with acute exposure to altitude may impair cognitive functions. No data exists on the effect this may have on the performance of medical staff in terms of patient examination, communication, decision-making, planning, and overall patient care. This study aims to close this knowledge gap. The investigators of this study aim to make rescue missions to high altitude safer for both the patients and the rescuers. To assess the effect of high altitude on patient care, the investigators recruit highly trained medical specialists who will perform patient care in simulated scenarios both at high altitude and at low altitude. These scenarios will be recorded and the performance of the medical specialists judged by independent reviewers. The medical specialists will also perform in simulated scenarios at high altitude two more times: once with supplementary oxygen, and once after spending a night at high altitude. the investigators do this to evaluate whether supplementary oxygen improves their performance, and whether symptoms of acute mountain sickness (which usually develop after spending the first night at high altitude) decreases their performance further.

Postoperative Complications of Orthopedic Surgery in Patients From High-altitude Regions

This study will focus on orthopedic surgery patients from high-altitude regions, utilizing smart wearables and monitoring tools to gather perioperative data, including heart rate, oxygen saturation, sleep quality, stress levels, and other relevant metrics. Regular follow-ups will assess recovery and complications, in addition to collecting medical records, lab results, imaging data, and other pertinent records. The ultimate goal is to establish a comprehensive follow-up cohort of orthopedic surgery patients from high-altitude areas.

Protocol for Evaluating Physiological and Psychological Adaptation Mechanisms in Tibetan Plateau Environments

This study is a single-center prospective observational study. It plans to use a series of physiological and medical instruments and international common physiological and psychological questionnaires. To dynamically detect the changes of physiological and psychological adaptability of doctors in Peking Union Medical College Hospital before leaving Beijing, 1-7 days after arriving at the plateau in Tibet during the acute phase of plateau hypoxic stress, 2 weeks, 3 months, 6 months, 12 months after staying in Tibet during the chronic phase of plateau hypoxic stress, and after returning to Beijing.