Advances in experimental medicine and biology最新文献

Blood flow modifies oxygen availability and biomechanical forces within the vasculature of the embryo as the hematopoietic system develops. The aorta-gonad-mesonephros (AGM) envelops the largest artery in the body and is a critical site for the emergence of hematopoietic stem cells (HSCs). Herein, I discuss the role of hypoxia-inducible factors (HIFs) and force as determinants of metabolism and fate determination. To address the effects of blood flow on hematopoietic development, I employ mouse embryo models and biomimetic culture. Real-time cell metabolic analyses show that oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) are altered by flow in cultures of AGM cells. Additionally, mitochondrial permeability transition pore (mPTP) activity assays indicate that mPTP opening is regulated as precursors commit to a hematopoietic fate. Moreover, transcriptome data suggest that expression of Ppif, the gene that encodes the mPTP regulator Cyclophilin D, may be downregulated by fluid force. Together, these data implicate blood flow in regulation of metabolic activity in the AGM region, influencing bioenergetics and serving as a cue for HSC emergence. The broader significance of this research lies in its potential to accurately recapitulate the hematopoietic niche in vitro for study of blood disorders and improvement of cellular therapies.

The aim of the study was to evaluate changes in eye movement conjugation in healthy volunteers in response to transcranial photobiomodulation (tPBM).

Materials and methods: 54 healthy volunteers (23 men, 31 women; median age was 23.5 years) were included in this retrospective, non-randomized study. Eye tracking (ET) was performed using the iPad app EyeTracker with a sampling rate of 20 Hz before and after 10 min tPBM (810 nm). The tracker calculated angular velocities in the vertical and horizontal planes (AV; vertical and horizontal). Data are shown as a median [interquartile range]. Pearson's correlation coefficients were used to assess agreement between computed variables. This coefficient value was designated as the vergence reactivity index (VRx), which reflects the eye movement conjugation. The differences were determined using the Wilcoxon T-criterion. The level of significance was p < 0.05.

Results: Vertical and horizontal VRx after tPBM were significantly higher than before the procedure: 0.878 [0.843; 0.902] vs. 0.783 [0.702; 0.829], p < 0.001, respectively and 0.875 [0.834; 0.912] vs. 0.927 [0.921; 0.93], p < 0.001, respectively.

Conclusion: Transcranial PBM causes a significant increase in vertical and horizontal vergence indices, which indicates an improvement in eye movement conjugation in healthy volunteers.

The focus of this overview is on the use of EPR oximetry in biological systems with an emphasis on soluble probes. EPR oximetry measures oxygen concentrations based on changes in electron spin relaxation of probes such as trityl and nitroxide radicals. The experimental relaxation rates depend on the inherent relaxation of the probe, the effects of probe-probe collisions, and the relaxation enhancement caused by collisions of the probe with O₂. To extract the oxygen concentration requires an understanding of all three contributions. The inherent relaxation rates of the probe depend on the rates of tumbling and on microwave frequency. The effects of probe-probe collisions depend on concentration, and for charged trityl radicals depend on ionic strength of the solution. The interactions of O₂ with nitroxide and trityl radicals can be described in terms of exchange interactions and the dynamics of collisions in solution. The spatial volume elements that can typically be observed in EPR imaging experiments are large enough that the volume could contain a range of concentrations of radicals and of O₂, which may result in distributions of linewidths and relaxation times that need to be considered in analyzing data. When using EPR oximetry in living systems, it is also necessary to consider whether the oxygen concentration is changing on the timescale of the experiment.

Assessment of oxygen saturation for biological tissues is crucial in many medical applications. A non-contact oxygenation measurement is important in clinical scenarios, for example, emergency situations and imaging-guided surgery, because non-contact measurement will speed up the measurement preparation by eliminating the need for cleaning skin and sensor for hygrine and placement of sensor. Near-infrared spectroscopy stands out as a key technology for probing tissue oxygenation. Non-contact measurement requires precise estimation of the distance between the tissue and the probe. However, high precision light detection and ranging in the near-infrared region is challenging to achieve when targeting biological tissues due to the strong light scattering. This challenge limits the design of non-contact instruments for oxygenation assessment.

Aim: The aim is to utilize time-of-flight (ToF) sensors to accurately determine both oxygenation (optical properties (OP), i.e., absorption and scattering coefficients) of biological tissues and the distance to these tissues.

Methods: Model-based direct ToF (DToF) models were built with a focus on highly scattering objects. A simulation study was performed to determine the OPs and distances. Two simulation tests were performed for a scattering object placed at 30 cm and 62 cm away. To demonstrate that the ToF measurements are sensitive to the OPs of the scattering object, we placed a tissue-mimicking phantom at 62 cm from the measurement plane, formed by a pulsed laser coupled to a collimator and a pinhole, while a single photon avalanche camera next to the emission point captures the ToF signals at four different wavelengths.

Results: In both cases, the retrieved OPs and distances were very close to the reference parameters with <0.5% average error, showing the accuracy of the optimization process. The multi-spectral ToF measurements confirmed the simulation.

Conclusion: We developed a model-based DToF approach for precise oxygenation measurement at a distance. This method holds great potential for non-contact oxygenation measurements, offering valuable insights for various clinical scenarios.

Oximetry is used to quantify the presence of oxygen in human blood within soft tissues of the human body. Among multiple implementations of this technology, pulsatile oxygen saturation (SpO₂) is a core medical technology and is being rapidly adopted in consumer health. However, despite its long history of clinical use, recent findings indicate that the accuracy of pulse oximetry may be affected by various factors and biases. For example, the COVID-19 pandemic showed that pulse oximeters exhibited flaws in accuracy due to the skin pigmentation of patients with darker skin. Thus, the future of this technology, particularly in consumer health devices, needs to be built on foundations that account for such biases. This chapter reviews the principles of pulse oximetry, sources of its artifacts, calibration methods, and the factors that may cause inaccuracy in pulse oximeters, particularly pertinent to two-wavelength pulse oximetry. Drawing upon recent research and clinical insights, we review the multifaceted nature of pulse oximetry biases, including motion artifacts, skin pigmentation, body mass index, environmental variables, device calibration, and nail polish, among others.

This chapter is dedicated to analysing how biological nuclear magnetic resonance (NMR) has evolved in the more than 70 years from its discovery and to discussing some of the applications of this technique to biological systems. To restrict a vast field, we treat liquid-state NMR leaving out solid-state applications that, although very important, are less consolidated and still fast evolving. We focus in particular on studies in complex environments, such as in-cell and/or crowded environments, that is a subject in which NMR can give its very best. We provide examples of various applications and hopefully show how versatile the technique is. We also briefly discuss how NMR can be coupled with other techniques to expand its horizons, increasing the intrinsic potentialities of this powerful technique.

The diffraction limit of visible light governs the spatial resolution of optical microscopy to roughly half the wavelength of the light, typically around 200 nm in the lateral dimension and 500 nm in the axial dimension. However, many subcellular structures and processes occur on a much smaller length scale. Technological solutions beyond the optical diffraction limit are needed to study subcellular organizations of proteins and their related functions. Super-resolution microscopy (SRM) represents a family of techniques capable of resolving structures and objects below the optical diffraction limit. This chapter provides an overview of three super-resolution techniques, stimulated emission depletion (STED) microscopy, structured illumination microscopy (SIM), and single-molecule localization microscopy (SMLM), and their applications in investigating subcellular protein organizations and related functions in immune cells.

Introduction: The attitudes of healthcare providers towards people with mental illness have caused significant concern for the research community.

Aim: The purpose of this systematic review was to examine the literature on the attitudes of healthcare professionals working in primary care settings towards people with mental illness.

Methodology: A systematic search was conducted in the PubMed database, focusing on cross-sectional articles published between 2017 and 2024. The search used the concepts of 'healthcare professionals', 'primary health care', 'attitudes', 'stigma', and 'mental illness'. Articles that met the inclusion and exclusion criteria were summarized.

Results: A total of 214 studies were identified in the initial search, with 12 studies included in the final review. Eleven of the 12 studies were conducted in Asia, the Middle East, South America, and Africa, and one study in Europe. Negative attitudes towards people with mental illness were a common finding among primary healthcare professionals in these studies. Contributing factors included low educational levels, older age, cultural influences, personal contact with people with mental illness, and insufficient mental health training. Educational and training interventions were recommended in all studies to improve these attitudes.

Conclusions: Healthcare professionals working in primary care often hold negative attitudes towards people with mental illness. The need for further education and training for healthcare professionals should be comprehensively addressed in future research.

Purpose: This study investigates the rates and causes of treatment discontinuation in one of the two public residential inpatient therapeutic programs for alcohol use disorder in Greece. Both programs are managed by the Department for the Treatment of Alcohol Use Disorder at the Psychiatric Hospital of Attica. The program examined in this study lasts 3 months and is followed by a Comprehensive Community Reintegration phase.

Methods: The study analyzed reasons for treatment discontinuation among 402 consecutive admissions to the residential program. Data were collected from the Patient Registry and participants' Medical and Clinical Records.

Results: Of the 402 consecutive admissions, 156 participants (38.8%) discontinued the program during the residential phase. Among these, 37.82% left voluntarily against medical advice, 6.4% left due to physical health issues, and 3.84% left due to a relapse of comorbid psychiatric disorders. The remaining participants were discharged and referred to other care facilities for reasons including forming intimate relationships (13%), verbal abuse (5.12%), unauthorized use of benzodiazepines (11.5%), and testing positive for drugs or alcohol (7.68%).

Conclusions: A significant proportion of participants in the residential inpatient therapeutic program for alcohol use disorder discontinue treatment, with over a half leaving voluntarily despite thorough preadmission preparation. This highlights ongoing clinical challenges, including addressing emerging psychopathological issues within the program's structured environment and enhancing participants' motivation for treatment.

Patients with hemoglobinopathies have both acute and chronic complications of the disease, which negatively affect their quality of life. The assessment of quality of life and mental resilience in these patients is an important tool to document both the degree of their burden and the important role of mental resilience as a tool to improve quality of life. The aim of the study was to assess the quality of life of people with hemoglobinopathies in Greece, their mental resilience, and their satisfaction with life. A cross-sectional study involving 96 adult patients with hemoglobinopathies was conducted. The instruments used were the "Connor-Davidson Resilience Scale," the "Life Satisfaction Scale (Satisfaction With Life Scale)," and the "Quality of Life Scale (WHOQOL-BREF)." According to the results, increased mental resilience and good adaptation to the stress of the disease, fairly high life satisfaction, and a fairly good level of quality of life were recorded. Little difference in quality of life was observed between thalassemia patients and sickle cell anemia patients.