Microbial Translocation and Perinatal Asphyxia/Hypoxia: A Systematic Review

The microbiome is vital for the proper function of the gastrointestinal tract (GIT) and the maintenance of overall wellbeing. Gut ischemia may lead to disruption of the intestinal mucosal barrier, resulting in bacterial translocation. In this systematic review, according to PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, we constructed a search query using the PICOT (Patient, Intervention, Comparison, Outcome, Time) framework. Eligible studies reported in PubMed, up to April 2021 were selected, from which, 57 publications’ data were included. According to these, escape of intraluminal potentially harmful factors into the systemic circulation and their transmission to distant organs and tissues, in utero, at birth, or immediately after, can be caused by reduced blood oxygenation. Various factors are involved in this situation. The GIT is a target organ, with high sensitivity to ischemia–hypoxia, and even short periods of ischemia may cause significant local tissue damage. Fetal hypoxia and perinatal asphyxia reduce bowel motility, especially in preterm neonates. Despite the fact that microbiome arouse the interest of scientists in recent decades, the pathophysiologic patterns which mediate in perinatal hypoxia/asphyxia conditions and gut function have not yet been well understood.

Membránové kontaktory a jejich aplikační potenciál

Nowadays, due to the scarcity of natural resources, there is more pressure on the reuse of materials and the application of circular economy principles. For this purpose, increasingly efficient and energy-saving technologies capable of extracting valuable raw materials from waste streams are needed, thus reducing energy and material dependence on primary resources. One such innovative technology is represented by membrane contactors, which enable mass sharing without the need for phase dispersion within each other, thus achieving lower operational and space requirements, as compared to conventional mass sharing devices (e.g. packed bed, tower column or stirred bed reactors). In addition, membrane contactors are very versatile and can be used not only for the recovery of valuable materials from waste streams in waste management processes (in particular recycling of metals or organics), but also as life-saving devices in biomedical applications (e.g. as extracorporeal blood oxygenation devices).

Disrupted White Matter Functional Connectivity With the Cerebral Cortex in Migraine Patients

Background: In attempts to understand the migraine patients’ overall brain functional architecture, blood oxygenation level-dependent (BOLD) signals in the white matter (WM) and gray matter (GM) were considered in the current study. Migraine, a severe and multiphasic brain condition, is characterized by recurrent attacks of headaches. BOLD fluctuations in a resting state exhibit similar temporal and spectral profiles in both WM and GM. It is feasible to explore the functional interactions between WM tracts and GM regions in migraine.Methods: Forty-eight migraineurs without aura (MWoA) and 48 healthy controls underwent resting-state functional magnetic resonance imaging. Pearson’s correlations between the mean time courses of 48 white matter (WM) bundles and 82 gray matter (GM) regions were computed for each subject. Two-sample t-tests were performed on the Pearson’s correlation coefficients (CC) to compare the differences between the MWoA and healthy controls in the GM-averaged CC of each bundle and the WM-averaged CC of each GM region.Results: The MWoAs exhibited an overall decreased average temporal CC between BOLD signals in 82 GM regions and 48 WM bundles compared with healthy controls, while little was increased. In particular, WM bundles such as left anterior corona radiata, left external capsule and bilateral superior longitudinal fasciculus had significantly decreased mean CCs with GM in MWoA. On the other hand, 16 GM regions had significantly decreased mean CCs with WM in MWoA, including some areas that are parts of the somatosensory regions, auditory cortex, temporal areas, frontal areas, cingulate cortex, and parietal cortex.Conclusion: Decreased functional connections between WM bundles and GM regions might contribute to disrupted functional connectivity between the parts of the pain processing pathway in MWoAs, which indicated that functional and connectivity abnormalities in cortical regions may not be limited to GM regions but are instead associated with functional abnormalities in WM tracts.

Photoacoustic imaging of 3D-printed vascular networks

Thrombosis in the circulation system can lead to major myocardial infarction and cardiovascular deaths. Understanding thrombosis formation is necessary for developing safe and effective treatments. In this work, using digital light processing (DLP)-based 3D printing, we fabricated sophisticated in vitro models of blood vessels with internal microchannels that can be used for thrombosis studies. In this regard, photoacoustic microscopy (PAM) offers a unique advantage for label-free visualization of the 3D-printed vessel models, with large penetration depth and functional sensitivity. We compared the imaging performances of two PAM implementations: optical-resolution PAM and acoustic-resolution PAM, and investigated 3D printed- vessel structures with different patterns of microchannels. Our results show that PAM can provide clear microchannel structures at depths up to 3.6 mm. We further quantified the blood oxygenation in the 3D-printed vascular models, showing that thrombi had lower oxygenation than the normal blood. We expect that PAM can find broad applications in 3D printing and bioprinting for in vitro studies of various vascular and other diseases.

Flow augmentation STA-MCA bypass evaluation for patients with acute stroke and unilateral large vessel occlusion: a proposal for an urgent bypass flowchart

OBJECTIVE Endovascular recanalization trials have shown a positive impact on the preservation of ischemic penumbra in patients with acute large vessel occlusion (LVO). The concept of penumbra salvation can be extended to surgical revascularization with bypass in highly selected patients. For selecting these patients, the authors propose a flowchart based on multimodal MRI. METHODS All patients with acute stroke and persisting internal carotid artery (ICA) or M1 occlusion after intravenous lysis or mechanical thrombectomy undergo advanced neuroimaging in a time window of 72 hours after stroke onset including perfusion MRI, blood oxygenation level–dependent functional MRI to evaluate cerebrovascular reactivity (BOLD-CVR), and noninvasive optimal vessel analysis (NOVA) quantitative MRA to assess collateral circulation. RESULTS Symptomatic patients exhibiting persistent hemodynamic impairment and insufficient collateral circulation could benefit from bypass surgery. According to the flowchart, a bypass is considered for patients 1) with low or moderate neurological impairment (National Institutes of Health Stroke Scale score 1–15, modified Rankin Scale score ≤ 3), 2) without large or malignant stroke, 3) without intracranial hemorrhage, 4) with MR perfusion/diffusion mismatch > 120%, 5) with paradoxical BOLD-CVR in the occluded vascular territory, and 6) with insufficient collateral circulation. CONCLUSIONS The proposed flowchart is based on the patient’s clinical condition and multimodal MR neuroimaging and aims to select patients with acute stroke due to LVO and persistent inadequate collateral flow, who could benefit from urgent bypass.

Strategic Modification of Gut Microbiota through Oral Bacteriotherapy Influences Hypoxia Inducible Factor-1α: Therapeutic Implication in Alzheimer’s Disease

Dysbiosis contributes to Alzheimer’s disease (AD) pathogenesis, and oral bacteriotherapy represents a promising preventative and therapeutic opportunity to remodel gut microbiota and to delay AD onset and progression by reducing neuroinflammation and amyloid and tau proteins aggregation. Specifically, SLAB51 multi-strain probiotic formulation positively influences multiple neuro-chemical pathways, but exact links between probiotics oral consumption and cerebral beneficial effects remain a gap of knowledge. Considering that cerebral blood oxygenation is particularly reduced in AD and that the decreased neurovascular function contributes to AD damages, hypoxia conditioning represents an encouraging strategy to cure diseases of the central nervous system. In this work, 8-week-old 3xTg-AD and wild-type mice were chronically supplemented with SLAB51 to evaluate effects on hypoxia-inducible factor-1α (HIF-1α), a key molecule regulating host-microbial crosstalk and a potential target in neurodegenerative pathologies. We report evidence that chronic supplementation with SLAB51 enhanced cerebral expression of HIF-1α and decreased levels of prolyl hydroxylase 2 (PHD2), an oxygen dependent regulator of HIF-1α degradation; moreover, it successfully counteracted the increase of inducible nitric oxide synthase (iNOS) brain expression and nitric oxide plasma levels in AD mice. Altogether, the results demonstrate an additional mechanism through which SLAB51 exerts neuroprotective and anti-inflammatory effects in this model of AD.

Evaluation of a Pneumatic Vest to Treat Symptoms of ARDS Caused by COVID-19

Critical care patients who experience symptoms of acute respiratory distress syndrome are commonly placed on mechanical ventilators to increase the oxygen provided to their pulmonary systems and monitor their condition. With the pulmonary inflammation typically accompanying ARDS, patients can experience lower ventilation-perfusion ratios resulting in lower blood oxygenation. In these cases, patients are typically rotated into a prone position to facilitate improved blood flow to portions of the lung that were not previously participating in the gas exchange process. However, proning a patient increases the risk of complications, requires up to seven hospital staff members to carry out, and does not guarantee an improvement in the patient's condition. The low-cost vest presented here was designed to reproduce the effects of proning while also requiring less hospital staff than the proning process. Additionally, the V/Q Vest helps hospital staff predict whether patients would respond well to a proning treatment. A pilot study was conducted on nine patients with ARDS from Coronavirus disease 2019 (COVID-19). The average increase in oxygenation with the V/Q Vest treatment for all patients was 19.7 ± 38.1%. Six of the nine patients responded positively to the V/Q Vest treatment, exhibiting increased oxygenation. The V/Q Vest also helped hospital staff predict that three of the five patients that were proned would experience an increase in oxygenation. An increase in oxygenation resulting from V/Q Vest treatment exceeded that of the proning treatment in two of these five proned patients.

Ultra-high-speed multi-parametric photoacoustic microscopy

Multi-parametric photoacoustic microscopy (PAM) is uniquely capable of simultaneous, high-resolution mapping of blood hemoglobin concentration, oxygenation, and flow in vivo. However, its speed has been limited by the dense sampling required for blood flow quantification. To overcome this limitation, we have developed an ultra-high-speed multi-parametric PAM system, which enables simultaneous acquisition of ~500 densely sampled B-scans by superposing the rapid laser scanning across the line-shaped focus of a cylindrically focused ultrasonic transducer over the conventional mechanical scan of the optical-acoustic dual foci. A novel optical-acoustic combiner is designed and implemented to accommodate the short working distance of the transducer, enabling convenient confocal alignment of the dual foci in the reflection mode. This new system enables continuous monitoring of microvascular hemoglobin concentration, blood oxygenation, and flow over a 4.5 x 3 mm2 area in the awake mouse brain with high spatial and temporal resolution (6.9 μm and 0.3 Hz, respectively).

Dynamics of the Third Wave of COVID-19 from the Perspective of the Emergency Department in a Large Regional Hospital—Single Center Observational Study

Background: The outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic has caused many significant social and economic changes. The consecutive waves of the epidemic in various countries have had dissimilar courses depending on the methods used to combat it. The aim of this study was to determine the dynamics of the third wave of COVID-19 from the perspective of emergency departments (ED). Methods: This was a retrospective review of medical records from ED. The authors have identified the most frequent symptoms. Prognostic factors have been chosen—prognostic scales, length of stay (LOS)—and a number of resources required have been calculated. Results: As the time passed, there were fewer patients and they presented mild symptoms. A statistically significant difference was observed in the median of blood oxygenation measurement (p = 0.00009), CRP level (p = 0.0016), and admission rate. Patients admitted to the hospital required more resources at ED. LOS was shorter in patients discharged home (p < 0.0001). Conclusions: The blood oxygen saturation (SPO2) and CPR levels can be helpful in decision-making regarding medical treatment. The fast-track for patients in good clinical condition may shorten the duration of stay in ED, and reduce the number of required resources.