Genome and clonal hematopoiesis stability contrasts with immune, cfDNA, mitochondrial, and telomere length changes during short duration spaceflight.

Background: The Inspiration4 (I4) mission, the first all-civilian orbital flight mission, investigated the physiological effects of short-duration spaceflight through a multi-omic approach. Despite advances, there remains much to learn about human adaptation to spaceflight's unique challenges, including microgravity, immune system perturbations, and radiation exposure. Methods: To provide a detailed genetics analysis of the mission, we collected dried blood spots pre-, during, and post-flight for DNA extraction. Telomere length was measured by quantitative PCR, while whole genome and cfDNA sequencing provided insight into genomic stability and immune adaptations. A robust bioinformatic pipeline was used for data analysis, including variant calling to assess mutational burden. Result: Telomere elongation occurred during spaceflight and shortened after return to Earth. Cell-free DNA analysis revealed increased immune cell signatures post-flight. No significant clonal hematopoiesis of indeterminate potential (CHIP) or whole-genome instability was observed. The long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months post-flight. Conclusion: Our findings provide valuable insights into the physiological consequences of short-duration spaceflight, with telomere dynamics and immune cell gene expression adapting to spaceflight and persisting after return to Earth. CHIP sequencing data will serve as a reference point for studying the early development of CHIP in astronauts, an understudied phenomenon as previous studies have focused on career astronauts. This study will serve as a reference point for future commercial and non-commercial spaceflight, low Earth orbit (LEO) missions, and deep-space exploration.

Layperson Physiological Tolerance and Operational Performance in Centrifuge-Simulated Spaceflight.

INTRODUCTION: Prior study has indicated that individuals of varied age, medical history, and limited-to-no experience tolerate spaceflight conditions. We sought to expand upon the understanding of layperson response to hypergravity conditions expected in commercial spaceflight by exposing subjects, following minimal training, to centrifuge-simulated, high-fidelity commercial spaceflight profiles. We further explored how these individuals perform in simulated operational activities during and following hypergravity.METHODS: Volunteer subjects participated in up to five centrifuge runs (maximum +4.0 Gz, +4.5 Gx, 6.1 G resultant; onset rate <0.5 Gz · s-1, ≤1 Gx · s-1). Profiles included two winged spacecraft simulations with sequential and combined +Gx/+Gz and two capsule simulations representing nominal +Gx launch and reentry. The final profile simulated a capsule launch abort, with a more dynamic cycling of +Gx exposures and oscillatory multi-axis exposures simulating parachutes and water motion. Touchscreen tablets were used to administer pattern-replication tasks during and after profiles.RESULTS: A total of 46 subjects participated, including 4 diabetics and 9 with cardiac disease. There was increased frequency of motion sickness, subjectively associated with capsule-type profiles, and increased termination of participation compared to prior studies. There was no association between medical history, age, sex, or motion sickness history and tolerance or noncompletion. Tablet test errors were common; accuracy and time to completion were associated with age. There was no association between any time metric or accuracy and sex.DISCUSSION: This study improves understanding of layperson tolerance in commercial spaceflight analog conditions, and the capsular profiles broaden the applicability of the findings. The frequency of task errors highlights the potential for mistakes in operational activities when performed by laypersons.Blue RS, Ong KM, Ray K, Menon A, Mateus J, Auñón-Chancellor S, Shah R, Powers W. Layperson physiological tolerance and operational performance in centrifuge-simulated spaceflight. Aerosp Med Hum Perform. 2023; 94(8):584-595.

Collection of Biospecimens from the Inspiration4 Mission Establishes the Standards for the Space Omics and Medical Atlas (SOMA).

The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from the crew at different stages of the mission, including before (L-92, L-44, L-3 days), during (FD1, FD2, FD3), and after (R+1, R+45, R+82, R+194 days) spaceflight, creating a longitudinal sample set. The collection process included samples such as venous blood, capillary dried blood spot cards, saliva, urine, stool, body swabs, capsule swabs, SpaceX Dragon capsule HEPA filter, and skin biopsies, which were processed to obtain aliquots of serum, plasma, extracellular vesicles, and peripheral blood mononuclear cells. All samples were then processed in clinical and research laboratories for optimal isolation and testing of DNA, RNA, proteins, metabolites, and other biomolecules. This paper describes the complete set of collected biospecimens, their processing steps, and long-term biobanking methods, which enable future molecular assays and testing. As such, this study details a robust framework for obtaining and preserving high-quality human, microbial, and environmental samples for aerospace medicine in the Space Omics and Medical Atlas (SOMA) initiative, which can also aid future experiments in human spaceflight and space biology.

Reporte de Caso Clínico y discusión de tema: Síndrome del opérculo Torßcico / Descrição do caso clínico e discussão do tema: síndrome do desfiladeiro torßcico / Report and discussion of a study case: Thoracic Outlet Syndrome

Introdución: El síndrome del Opérculo Torßcico (SOT) es un grupo heterogéneo y potencialmente disfuncional de síndromes relacionados con compresión extrínseca de estructuras neurovasculares a su paso, desde el cuello hacia el miembro superior, por diferentes estructuras anatómicas congénitas o adquiridas, siendo mßs frecuente la compresión neurológica, ocasionando una variedad de sintomatología que varía según grado de compresión y estructura afectada, que en algunos casos hacen difícil su diagnóstico. Es una entidad mal diagnosticada teniendo en cuenta que no hay criterios diagnósticos establecidos; por eso, el examen físico es primordial para su sospecha clínica. El tratamiento inicial es conservador, siendo el tratamiento quirúrgico, una opción con múltiples procedimientos personalizados para cada tipo de paciente, según etiología. Objetivo: El propósito del artículo es realizar una discusión del caso clínico basada en la evidencia, para permitir un conocimiento general de esta patología, y comprender que hace parte de las causas de dolor en miembro superior, para así orientar al profesional de la salud a realizar un diagnóstico oportuno y un tratamiento efectivo que disminuya el riesgo de complicaciones irreversibles.

Introduction: Thoracic Outlet Syndrome - TOS - is a heterogeneous and potentially dysfunctional group of syndromes related to extrinsic compression of neurovascular structures from the neck to the upper limb for different congenital or acquired anatomical structures, being more frequent the neurological compression, causing a variety of symptoms that vary according to the degree of compression and affected structure that in some cases make it difficult to diagnose. Due to the lack of established diagnostic criteria, the physical exam is the most important element used to formulate a diagnosis. The initial treatment is conservative. The surgical treatment becomes an option with multiple personalized procedures for each type of patient according to the etiology. Objective: The purpose of the article is to discuss the clinical case based on the evidence allowing general knowledge of that pathology, and understanding the causes of pain in the upper limb, to therefore guide medical staff to perform a timely diagnosis and effective treatment that decreases the risk of irreversible complications.

Introdução: A Síndrome do desfiladeiro Toraxico (SOT) é um grupo heterogéneo e potencialmente disfuncional de síndromes relacionadas à compressão extrínseca de estruturas neurovasculares da passagem do pescoço para o membro superior por diferentes estruturas anatômicas congênitas ou adquiridas, sendo a compressão neurológica mais frequente, sua varieda sintomatología depende do grau de compressão e da estrutura afectada, o que em alguns casos podem dificultar o seu diagnóstico. É uma doença mal diagnosticada porque não hß criterios estabelecidos para o diagnóstico; por esta razão o exame físico é fundamental na suspeita clínica. O tratamento inicial é conservador, sendo a opção cirúrgico uma intervenção com múltiplos procedimentos personalizados acordo com a etiologia do paciente. Objetivo: O objetivo deste artigo é realizar uma discussão do caso clínico com base em provas, que permita um conhecimento geral da doença, e entender que faz parte das causas de dor no membro superior permitindo orientar o profissional de saúde a fazer um diagnóstico oportuno e um tratamento eficaz a fim de reduzir o risco de complicações irreversíveis. (au)

Bone hemodynamic responses to changes in external pressure.

Adequate blood supply and circulation to the bones is required to maintain a healthy skeleton. Inadequate blood perfusion is associated with numerous bone pathologies and a decrease in bone mineral density, yet bone hemodynamics remains poorly understood. This study aims to 1) quantify bone hemodynamic responses to changes in external pressure, and 2) identify the predominant mechanisms regulating bone hemodynamic responses to pressure changes. Photoplethysmography was used to measure bone and skin perfusion in response to changes in external pressure. Single-limb pressure chamber experiments were performed over a pressure range of -50 to +50mmHg. Bone perfusion is decreased at all negative pressures, and larger decrements in perfusion are observed at the more extreme pressure differences. At positive pressures we observed an initial increase in perfusion followed by activation of intramuscular pressure receptors at +30mmHg, which overrides the initial response and results in decreased perfusion at the highest positive pressure levels. The myogenic effect is observed and is shown to be the predominant control mechanism in bone over a wide range of pressure exposures. Greater understanding of these hemodynamic mechanisms may be important in developing new drugs and therapies to treat various bone disorders.

Photoplethysmography for non-invasive in vivo measurement of bone hemodynamics.

Developments in photoplethysmography (PPG) hardware make this device a promising tool for non-invasive deep-tissue hemodynamic measurements. The aim of this study was to validate the use of PPG as a tool for non-invasive bone hemodynamic measurements. A new PPG device capable of measuring bone hemodynamic responses was designed, tested and validated. Validation experiments included cold exposure, arterial occlusion, skin occlusion and nitroglycerin exposure. Cold exposure resulted in a decrease in skin perfusion (p = 0.011) and bone perfusion (p = 0.005); arterial occlusion also resulted in decreased skin perfusion (p < 0.001) and bone perfusion (p = 0.008), with arterial occlusion resulting in a greater decrease in perfusion than cold exposure. The independence of the skin and bone PPG signals was demonstrated by the ability to independently increase (p = 0.003) and decrease (p = 0.005) the skin signal without significantly affecting the bone signal. Our experiments build upon and expand previous PPG developments and validation studies. Our custom-made PPG hardware represents a state-of-the-art tool for non-invasive monitoring of deep tissues, and our data support the use of PPG as a valid tool for measuring bone hemodynamic responses in vivo.

Toe blood pressure and leg muscle oxygenation with body posture.

INTRODUCTION: In 1980 Katkov and Chestukhin measured blood pressures and oxygenation invasively at various body tilt angles at different locations on the body, including the foot. To our knowledge, such measurements have not been performed noninvasively. Therefore, the purpose of this study was to measure toe blood pressure (TBP) and lower limb muscle oxygenation noninvasively at various body tilt angles, and to assess the use of a Finometer for noninvasive TBP measurements. Our noninvasive results are compared with those performed by Katkov and Chestukhin. We hypothesized that: 1) the Finometer provides a noninvasive measurement of TBP at different tilt angles; and 2) muscle oxygenation is highest with 0 and -6 degrees, and decreases with increased head-up tilt (HUT). METHODS: There were 10 subjects who were exposed to different body tilt angles (-6, 0, 10, 30, 70, and 90 degrees). At each angle we measured TBP noninvasively with a Finometer and muscle tissue oxygenation by near infrared spectroscopy. RESULTS: We found a strong correlation between TBP using the Finometer and TBP predicted by adding the hydrostatic component due to body tilt to the standard arm blood pressure measurement. At 10, 30, 70, and 90 degrees both TBP and tissue oxygenation were significantly different from the 0 degree (supine) level. Oxygenation decreased and TBP increased with higher HUT angles. No differences were observed in TBP or oxygenation between -6 and 0 degree. CONCLUSIONS: The Finometer accurately measures TBP noninvasively with body tilt. Also, muscle oxygenation is highest at small HUT angles and decreases with increased HUT.

Asymmetry in vestibular responses to cross-coupled stimulus.

Head turns performed while rotating about another axis result in a cross-coupled stimulus (CCS) to the vestibular system. The CCS causes a tumbling sensation, and the magnitude of the tumbling sensation is dependent on the type of head turn (HT) that is performed. Asymmetric CCS responses to different rotational directions are widely acknowledged, yet poorly understood. The objective of this study was to: 1) correctly describe the asymmetries in responses to different configurations of CCS stimulation and 2) test two previously proposed hypotheses for explaining the asymmetries, dominant direction, and dominant end position. The dominant direction hypothesis states that the tumbling sensations evoked by the CCS will be more intense for certain directions of the tumbling sensation than for others. The dominant end position hypothesis states that head turns ending in the nose-up position result in more intense sensations than those ending on the side positions. Subjects performed four types of 60-degree yaw head turns while lying horizontally on a centrifuge. Subjects were either supine or prone, while rotating clockwise or counterclockwise. Three experimental conditions were tested: clockwise supine (n = 33); counterclockwise supine (n = 10); and clockwise prone (n = 10). Subjective tumbling intensity scores were recorded for each head turn. Head turns to the left are dominant for clockwise supine centrifugation (P < 0.0001) and head turns to the right are dominant for counterclockwise supine centrifugation (P = 0.0020), matching what is expected from previous studies. However, for prone centrifugation, head turns to the left are more intense than head turns to the right (P = 0.0078), refuting the dominant direction hypothesis. The dominant end position effect is small in magnitude and cannot by itself explain the asymmetries. For every test condition, there is a dominant direction, but the dominant direction is not just a function of the HT and centrifuge rotation directions, instead it is also dependent on the subject's orientation on the centrifuge. An alternative perceived danger hypothesis that matches the data from all three experiments is proposed.

Use of short-radius centrifugation to augment ankle-brachial indices.

BACKGROUND: Peripheral arterial disease is mainly caused by atherosclerosis and is characterized by decreased circulation, lower blood pressure, and insufficient tissue perfusion in the lower extremities. The hemodynamics of standing and altered gravity environments have been well studied relative to arm blood pressures but are less well understood for ankle pressures. METHODS: Because regional blood pressure depends, in part, on the gravitational pressure gradient, we hypothesized that artificial gravity exposure on a short-arm centrifuge with the center of rotation above the head would increase blood pressure in the lower extremities. Cardiovascular parameters for 12 healthy subjects were measured during exposure to supine short-arm centrifugation at 20, 25, and 30 revolutions per minute (rpm), corresponding to centripetal accelerations of 0.94, 1.47, and 2.11 Gz at the foot level, respectively. RESULTS: Systolic ankle blood pressure significantly increased at all levels of centrifugation. Ankle-brachial indices (the ratio of systolic ankle to arm blood pressures) increased significantly from 1.17 +/- 0.03 to 1.58 +/- 0.03 at 0.94 Gz (P < 0.005), 1.74 +/- 0.02 at 1.47 Gz (P < 0.005), and 1.89 +/- 0.06 at 2.11 Gz (P < 0.005). Systolic arm blood pressure significantly increased at 2.11 Gz, but heart rate did not change significantly. All parameters returned to normal after cessation of centrifugation. CONCLUSIONS: We demonstrated that short-radius centrifugation leads to an increase in ankle-brachial indices. This could have potential implications for the treatment of peripheral arterial disease.

Medición del ión flúor presente en la sal producida y comercializada en Colombia / Measurement of ion-fluoride contents in the salt produced and marketed in Colombia

Con esta investigación de tipo descriptivo y no experimental se pretendió conocer la concentración de flúor en partes por millón (ppm) presente en la sal de consumo humano, producida y comercializada en Colombia. Mediante la compra directa, se realizó un muestreo de carácter intencional de 88 bolsas de sal de una población correspondiente a 189 marcas. La detección del ión flúor se realizó mediante el método del electrodo específico de flúor (Cat VWR No. 34-105-106. Orion, modelo 96-09-00). Los resultados fueron analizados mediante la prueba t de Student (p menor 0.025). El valor máximo del flúor en las muestras fue de 215.6 ppm y el valor mínimo de 3.3 ppm; sólo el 5.6 por ciento de los valores de las muestras se localió dentro del rango entre 180 y 220 ppm, en controversia con investigaciones similares que han encontrados concentraciones superiores a 220 ppm. Se encontraron diferencias de alta significancia entre los valores del análisis químico del empaque/decreto. El estudio mostró que no hay cumplimiento satisfactorio en cuanto al suministro de flúor para una fluorización sistémica en Colombia y que se debe continuar con la investigación en este tópico