« Go Back

Research Containing: Human Research

Men and women in space: bone loss and kidney stone risk after long-duration spaceflight

by on 9 June 2015in Biology & Biotechnology No comment

Bone loss, a key concern for long-duration space travelers, is typically considered a female issue. The number of women who have flown long-duration space missions is now great enough to allow a quantitative comparison of changes in bone and renal stone risk by sex. Participants were 42 astronauts (33 men and 9 women) on long-duration missions to the International Space Station. Bone mineral density (by dual-energy X-ray absorptiometry) and biochemical markers of bone metabolism (from blood and urine samples) were evaluated before and after flight. Data were analyzed in two groups, based on available resistance exercise equipment. Missions were 49 to 215 days in duration, flown between 2000 and 2012. The bone density response to spaceflight was the same for men and women in both exercise groups. The bone mineral density response to flight was the same for men and women, and the typical decrease in bone mineral density (whole body and/or regional) after flight was not observed for either sex for those using an advanced resistive exercise device. Biochemical markers of bone formation and resorption responded similarly in male and female astronauts. The response of urinary supersaturation risk to spaceflight was not significantly different between men and women, although risks were typically increased after flight in both groups, and risks were greater in men than in women before and after flight. The responses of men and women to spaceflight with respect to these measures of bone health were not different.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/24470067

Recovery of spaceflight-induced bone loss: Bone mineral density after long-duration missions as fitted with an exponential function

by on 9 June 2015in Biology & Biotechnology No comment

The loss of bone mineral in NASA astronauts during spaceflight has been investigated throughout the more than 40 years of space travel. Consequently, it is a medical requirement at NASA Johnson Space Center (JSC) that changes in bone mass be monitored in crew members by measuring bone mineral density (BMD), with dual-energy X-ray absorptiometry (DXA) before and after flight, of astronauts who serve on long-duration missions (4?6 months). We evaluated this repository of medical data to track whether there is recovery of bone mineral that was lost during spaceflight.Our analysis was supplemented by BMD data from cosmonauts (by convention, a space traveler formally employed by the Russia Aviation and Space Agency or by the previous Soviet Union) who had also flown on long-duration missions. Data from a total of 45 individual crew members a small number of whom flew on more than one mission were used in this analysis. Changes in BMD (between 56 different sets of pre- and postflight measurements) were plotted as a function of time (days after landing). Plotted BMD changes were fitted to an exponential mathematical function that estimated: (i) BMD change on landing day (day 0) and (ii) the number of days after landing when 50% of the lost bone would be recovered (50% recovery time) in the lumbar spine, trochanter, pelvis, femoral neck and calcaneus. In sum, averaged losses of bone mineral after long-duration spaceflight ranged between 2% and 9% across all sites with our recovery model predicting a 50% restoration of bone loss for all sites to be within 9 months.

Related URLs:
http://dx.doi.org/10.1016/j.bone.2007.08.022

Musculoskeletal injuries and minor trauma in space: incidence and injury mechanisms in U.S. astronauts

by on 9 June 2015in Biology & Biotechnology No comment

INTRODUCTION: Astronauts have sustained musculoskeletal injuries and minor trauma in space, but our knowledge of these injuries is based mainly on anecdotal reports. The purpose of our study was to catalog and analyze all in-flight musculoskeletal injuries occurring throughout the U.S. space program to date. METHODS: A database on in-flight musculoskeletal injuries among U.S. astronauts was generated from records at the Johnson Space Center. RESULTS: A total of 219 in-flight musculoskeletal injuries were identified, 198 occurring in men and 21 in women. Incidence over the course of the space program was 0.021 per flight day for men and 0.015 for women. Hand injuries represented the most common location of injuries, with abrasions and small lacerations representing common manifestations of these injuries. Crew activity in the spacecraft cabin such as translating between modules, aerobic and resistive exercise, and injuries caused by the extravehicular activity (EVA) suit components were the leading causes of musculoskeletal injuries. Exercise-related injuries accounted for an incidence of 0.003 per day and exercise is the most frequent source of injuries in astronauts living aboard the International Space Station (ISS). Interaction with EVA suit components accounted for an incidence of 0.26 injuries per EVA. DISCUSSION: Hand injuries were among the most common events occurring in U.S. astronauts during spaceflight. Identifying the incidence and mechanism of in-flight injuries will allow flight surgeons to quantify the amount of medical supplies needed in the design of next-generation spacecraft. Engineers can use in-flight injury data to further refine the EVA suit and vehicle components.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/19198198

Application of equipment Sonocard for functional reserves evaluation during extravehicular activity

by on 9 June 2015in Biology & Biotechnology No comment

Introduction. Extravehicular activity (EVA) and working on ISS (International space station) is a very strong physical and psychoemotional activity for a human organism. At the same time it is important to know functional reserves of the organism before and after EVA. It is necessary to know cosmonaut’s fatigue and there’s expenditure of energy for working in space, and determination cosmonaut’s ability for further EVA. For solution these problems was used the device SONOCARD. This device has been using already for three years of the same name experiment and there is wide experience at monitoring and valuation recovery of crewmember’s functional reserves during the sleep. Methods. Study before working in the open space was performed for 5-10 days. Retest was performed at the first night after EVA. The device SONOCARD is to be carried in the T-shirt upper left pocket. Sensor of the device responds to breast microoscillations produced by cardiac beats and breathing. After waking-up, cosmonaut connects the device to intended PC for copying the night record into PC memory for ensuing downloading via the communication channels for the further exploration. Experimental sessions were performed during three EVA by two Russian cosmonauts. One of them participated in all EVA, another – only in two EVA. Results. All the cosmonauts hadn’t deviation at the parameters of autonomic regulation before and after EVA, sleep quality was good and effective. Established that each successive EVA requires a higher tension regulation systems. The cosmonaut, made three EVA, has index of tension of regulatory systems were 121, 124 and 213 current units respectively and pNN50 index was equal to 17,7%, 7,0% and 3,9%. It is also shown that the degree of tension of regulatory systems in the ISS, is higher the longer the stay in space. Conclusion. Using the device SONOCARD is a promising method for evaluating the functional reserves of the cosmonauts organism and the efficient planning of operations responsible EVA.

Related URLs:

"PULS" and "PNEUMOCARD" Autmoated Medical Control Syqstems Onboard the International Space Station

by on 9 June 2015in Biology & Biotechnology No comment

In the paper we shall consider the prospects for development of a computerized medical monitoring system the staple units of which are space modifications of devices Pulse and Pneumocard. Experiment Pulse is aimed at studying the autonomous cardiorespiratory system regulation during space flight. It was held during ISS increment 5 and 6. Method of heart rate variability (HRV) was used. Investigations during ISS-5 brought to light difference in the amount of functional reserve of the regulatory systems attested by low orthostatic endurance one of cosmonaut on return to Earth. Investigations during ISS-6 also produced valuable diagnostic and prognostic information. Scientific experiment Pulse is the first step towards integration of tis prognostics function into the current diagnostics-oriented medical monitoring system. Next step will be improvement and enhancement of Pneumocard procedures developed jointly by Russian and German partners. Development of an automated system for operative medical monitoring capable to process, analyze and evaluate medical information with an orbital computer is requirement of the times. We cannot linger with starting construction of the next generation of medical information systems. These systems will be in demand in near future for piloted missions to Mars.

Related URLs:
http://dx.doi.org/10.2514/6.IAC-03-G.2.04

[Immune system in Russian cosmonauts after orbital space flights]

by on 9 June 2015in Biology & Biotechnology No comment

The article is an overview of the results of studies of the immune systems of cosmonauts. The use of a system approach to the evaluation of the various components of the immune system made it possible to identify a number of characteristics of adaptive change, including the quantitative and functional changes of the innate and adaptive immunity. Among them the most important are: changes in in the system of Toll like receptors (TLRs) manifested as a decrease in the content of circulating monocytes and granulocytes expressing TLR2, TLR4, and TLR6, and LPS-induced cytokine production; inhibition of the functional potential of natural killer (NK)- and T-cells. The article discusses possible factors and mechanisms of the identified changes.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/25509881

Ultrasonic evaluation of pupillary light reflex

by on 9 June 2015in Biology & Biotechnology No comment

Background Evaluation of pupillary light reflex (PLR) is an important neurological test with a variety of clinical applications. Obstacles such as severe soft tissue damage or hyphema may obstruct the visual access to the pupil, thus rendering direct PLR observation difficult or impossible. Multipurpose ultrasonic systems, however, can overcome this problem. Methods Using ultrasound imaging, a coronal view of the iris and pupil allowed visualization of PLR upon contralateral stimulation with a penlight. The technique was tested in ten healthy volunteers and a trauma case study. Results Satisfactory visualization of the iris was achieved in all subjects, in an average time of 1 min 10 s. Temporal parameters of pupillary constriction, oscillations (hippos) and relaxation could also be measured on M-mode displays. Conclusions Real-time coronal imaging of the iris using multipurpose ultrasound imaging is found to be a practical, fast and recordable method that can be used for evaluating PLR.

Related URLs:
http://dx.doi.org/10.1007/s13089-009-0012-9

FAST at MACH 20: clinical ultrasound aboard the International Space Station

by on 9 June 2015in Biology & Biotechnology No comment

BACKGROUND: Focused assessment with sonography for trauma (FAST) examination has been proved accurate for diagnosing trauma when performed by nonradiologist physicians. Recent reports have suggested that nonphysicians also may be able to perform the FAST examination reliably. A multipurpose ultrasound system is installed on the International Space Station as a component of the Human Research Facility. Nonphysician crew members aboard the International Space Station receive modest training in hardware operation, sonographic techniques, and remotely guided scanning. This report documents the first FAST examination conducted in space, as part of the sustained effort to maintain the highest possible level of available medical care during long-duration space flight. METHODS: An International Space Station crew member with minimal sonography training was remotely guided through a FAST examination by an ultrasound imaging expert from Mission Control Center using private real-time two-way audio and a private space-to-ground video downlink (7.5 frames/second). There was a 2-second satellite delay for both video and audio. To facilitate the real-time telemedical ultrasound examination, identical reference cards showing topologic reference points and hardware controls were available to both the crew member and the ground-based expert. RESULTS: A FAST examination, including four standard abdominal windows, was completed in approximately 5.5 minutes. Following commands from the Mission Control Center-based expert, the crew member acquired all target images without difficulty. The anatomic content and fidelity of the ultrasound video were excellent and would allow clinical decision making. CONCLUSIONS: It is possible to conduct a remotely guided FAST examination with excellent clinical results and speed, even with a significantly reduced video frame rate and a 2-second communication latency. A wider application of trauma ultrasound applications for remote medicine on earth appears to be possible and warranted.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/15674147

Applicability of particle and heavy ion transport code PHITS to the shielding design of spacecrafts

by on 9 June 2015in Biology & Biotechnology No comment

Development of HZE particle transport codes is severely required for the shielding design of spacecrafts. One-dimensional deterministic codes are generally adopted in the shielding calculation because of their reasonable computational time, but three-dimensional Monte Carlo codes are also to be employed especially in the final step of the design with fully optimized geometries. We are therefore developing a general-purpose Monte Carlo code PHITS, which can deal with the transports of all kinds of hadrons and heavy ions with energies up to 200 GeV / n . For the purpose of examining the applicability of PHITS to the shielding design, neutron and charged particle spectra inside the Space Shuttle were calculated for an imaginary vessel whose shielding distribution is fitted to that of the real shuttle. Absorbed doses and dose equivalents were estimated from the spectra by applying fluence to dose conversion coefficients. The agreements between the calculated spectra or doses and the corresponding experimental data were generally satisfactory, especially for the neutron spectra, which have been barely reproduced by other studies. We therefore concluded that PHITS has a great possibility of playing an important role in the design study of spacecrafts.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S1350448706001430

Lung function is unchanged in the 1 G environment following 6-months exposure to microgravity

by on 9 June 2015in Biology & Biotechnology No comment

Many organ systems adapt in response to the removal of gravity, such as that occurring during spaceflight. Such adaptation occurs over varying time periods depending on the organ system being considered, but the effect is that upon a return to the normal 1 G environment, the organ system is ill-adapted to that environment. As a consequence, either countermeasures to the adaptive process in flight, or rehabilitation upon return to 1 G is required. To determine whether the lung changed in response to a long period without gravity, we studied numerous aspects of lung function on ten subjects (one female) before and after they were exposed to 4-6 months of microgravity (microG, weightlessness) in the normobaric normoxic environment of the International Space Station. With the exception of small (and likely physiologically inconsequential) changes in expiratory reserve volume, one index of peripheral gas mixing in the periphery of the lung, and a possible slight reduction in D(L)CO in the early postflight period despite an unchanged cardiac output, lung function was unaltered by 4-6 months in microG. These results suggest that unlike many other organ systems in the human body, lung function returns to normal after long term exposure to the removal of gravity. We conclude that that in a normoxic, normobaric environment, lung function is not a concern following long-duration future spaceflight exploration missions of up to 6 months.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/18481079