Search Results (57)

The Sarco Endoplasmic Reticulum Ca²⁺-ATPase (SERCA) pumps cytosolic Ca²⁺ into the endoplasmic reticulum lumen (ER) to maintain cytosolic and ER Ca²⁺ levels under physiological conditions. Previous reports suggest that cellular Ca²⁺ homeostasis is compromised in Alzheimer’s Disease (AD) and that SERCA activity can modulate the phenotype of AD mouse models. Here, we used a C. elegans strain that overexpresses the most toxic human ß-amyloid peptide (Aß_(1-42)) in body-wall muscle cells to study the effects of SERCA (sca-1) silencing on Aß_(1-42)-induced body-wall muscle dysfunction. sca-1 knockdown reduced the percentage of paralyzed worms, improved locomotion in free-mobility assays, and restored pharynx pumping in Aß_(1-42)-overexpressing worms. At the cellular level, sca-1 silencing partially prevented Aß_(1-42)-induced exacerbated mitochondrial respiration and mitochondrial ROS production and restored mitochondrial organization around sarcomeres. sca-1 knockdown reduced the number and size of Aß_(1-42) aggregates in body–wall muscle cells and prevented the formation of Aß_(1-42) oligomers. Aß_(1-42) expression induced a slower kinetics of spontaneous cytosolic Ca²⁺ transients in muscle cells and sca-1 partially restored these changes. We propose that partial sca-1 loss of function prevents the toxicity associated with beta-amyloid accumulation by reducing the formation of Aß_(1-42) oligomers and improving mitochondrial function, in a mechanism that requires remodeling of cytosolic Ca²⁺ dynamics and partial ER Ca²⁺ depletion. Full article

Background/Objectives: Abnormal differentiation of human skin fibroblasts into myofibroblasts contributes to fibrotic skin disorders such as hypertrophic scars, keloids, and Dupuytren’s disease. This process is characterized by increased fibroblast proliferation, enhanced differentiation into myofibroblasts, and reduced programmed cell death (apoptosis). We previously demonstrated that blue light irradiation (λ = 453 nm) significantly and dose-dependently inhibits both spontaneous and TGF-β-induced fibroblast differentiation. Methods: Because fibroblast differentiation depends on cellular energy metabolism, we investigated whether the inhibitory effect of blue light is linked to changes in the cells’ energy balance. Results: We found that blue light reduced TGF-β-induced differentiation, as shown by decreased levels of α-SMA and EDA-fibronectin, key markers of myofibroblast formation. This effect was strongly associated with almost complete inhibition of mitochondrial respiration, reduced glycolysis, a lower NAD⁺/NADH ratio, and decreased ATP production. ATP-dependent processes, including endocytosis and lysosomal activity, both essential parameters of fibroblast differentiation, were also strongly suppressed. Importantly, all these changes were fully reversible within 24 h after the last irradiation. Conclusions: Mechanistically, we propose that blue light triggers photochemical reduction in flavins in proteins of the respiratory chain and possibly the Krebs cycle, which temporarily alters cellular energy metabolism. These findings suggest that non-toxic blue light therapy (80 J/cm²) can effectively prevent factor-induced fibroblast differentiation and may serve as a standalone or supportive treatment to reduce fibrotic events such as scarring and keloid formation. Furthermore, our results indicate that targeting cellular energy metabolism, whether physically or pharmacologically, could be a promising strategy to prevent sclerotic skin disorders. Full article

This study investigates the feasibility of a dry electrode cap design for neonatal electroencephalogram (EEG) recordings. Recordings on a phantom and a real infant are compared between a novel dry electrode cap and a clinically used gel-based electrode cap. The phantom recordings included measuring both the electrode contact force and the signal quality during still and respiration-like head motion. The real infant recordings were assessed for the EEG signals’ spectral characteristics, including powerline interference. Compared to gel-based caps, the dry caps showed a largely comparable skin force, an expectedly greater sensitivity to motion-induced artifacts, and a slightly lower powerline interference. Recordings on the real infant showed no significant skin marks after using the dry electrode, and the spectral compositions were comparable between dry- and gel-based electrode caps. These findings suggest that neonatal EEG recordings with a dry electrode cap are technically feasible, but movement-related artifacts, such as respiration in a supine lying infant, may challenge long-term recordings of spontaneous EEG activity. Yet, the ease of use of dry electrode caps calls for future studies to define the optimal use case in neonatal recordings. Full article

Limited research exists on the carbon sequestration potential of spontaneously developing post-coal-mining sites in the mid-stage of primary succession. Therefore, in 2023, net ecosystem exchange (NEE) was quantified in Czechia using an eddy covariance (EC) tower to assess carbon fluxes in a spontaneously developing ecosystem dominated by pioneer tree species such as willow, along with aspen and birch, growing on a wave-like microtopography. The ecosystem functioned as a strong carbon sink, with an annual NEE of −415 g C m⁻² yr⁻¹, ~39 years after coal mining. This NEE was derived by gross ecosystem exchange (GEE) of −1423 g C m⁻² yr⁻¹ and ecosystem respiration (Reco) of 1008 g C m⁻² yr⁻¹. Seasonal variation was driven by higher GEE in summer rather than by Reco. Consequently, Reco accounted for ca. 51% of GEE in summer, compared to 56% in spring. In addition, temperature was an important climatic factor in spring, whereas vapor pressure deficit (VPD) and global radiation (Rg) were more critical in summer. Overall, our results highlight the robust carbon sequestration capacity of naturally developing pioneer forests, suggesting their potential role in restoring mined areas in Central Europe and other regions without water limitations following coal mining. Full article

Background and Objectives: Neuromuscular blocking agents are essential to ensure optimal surgical conditions during general anesthesia. Sugammadex, a selective binding agent, is widely used to reverse neuromuscular blockade. While weight-based dosing (2 mg/kg for moderate blockade) is recommended, many clinicians administer a fixed dose of 200 mg in clinical practice, potentially leading to overdosing. This study aimed to compare the efficacy and recovery profiles of weight-based and fixed-dose sugammadex in patients undergoing general anesthesia. Materials and Methods: In this randomized controlled trial, 20 patients were divided into two groups: the recommended dose group (R group, 2 mg/kg) and the fixed dose group (F group, 200 mg). Primary outcomes included time to achieve a normalized train-of-four (TOF) ratio of 0.9. Secondary outcomes included recovery time, time to spontaneous respiration, response to verbal commands and extubation, and adverse events. Results: The median time to achieve a normalized TOF ratio of 0.9 was 2.3 min in the R group and 2.0 min in the F group (p = 0.529). Secondary outcomes, including recovery time and time to extubation showed no significant differences. Adverse events were minimal and comparable between groups. Conclusions: The fixed-dose sugammadex (200 mg) demonstrated similar efficacy and safety to weight-based dosing (2 mg/kg) in reversing moderate neuromuscular blockade. These findings do not allow abandoning the recommendation of adjustment for body weight, particularly in patients with low body weight or comorbidities. Full article

Although the mitochondrial genome is an attribute of all eukaryotes, some yeast species (called petite-positive) can replicate without mitochondrial DNA (mtDNA). Strains without mtDNA (known as rho⁻ mutants or petite mutants) are respiration-deficient and require fermentable carbon sources (such as glucose) for their metabolism. However, they are compromised in many aspects of fitness and competitiveness. Nevertheless, a few research groups have reported that some petite mutants of Candida glabrata and Saccharomyces cerevisiae manifested higher levels of tolerance to the antifungal fluconazole than their wild-type (WT) counterparts. In this study, we show that elevated tolerance to two or three out of four tested antifungals is a generic feature of at least five petite-positive species of yeasts including C. glabrata (higher tolerance of petites to clotrimazole and miconazole), S. bayanus (tolerance to clotrimazole, fluconazole, and miconazole), S. cerevisiae (tolerance to clotrimazole and fluconazole), S. paradoxus (tolerance to clotrimazole, fluconazole, and miconazole), and S. pastorianus (tolerance to clotrimazole and fluconazole). Comparing the levels of tolerance to the antifungals in WT and petite mutants was based on measuring the diameters of the zones of inhibition (ZOIs) using disc diffusion assays. The mode of inhibition in the majority of WT strains by all antifungals was fungicidal; most of the rho⁻ mutants manifested fungistatic inhibition. We observed partial (not complete) inhibition in WT, with four different types of ZOI patterns that were species- and antifungal-specific. The partial inhibition was characterised by the presence of antifungal-tolerant colonies within ZOI areas. The inability of these colonies selected from ZOIs to grow on glycerol, as a single source of carbon, proved that they were rho⁻ mutants spontaneously generated in the WT populations. The results on the elevated tolerance of petite strains to antifungals are discussed in terms of the prospective positive selection of respiratory-deficient mutants and the various implications of such selection. Full article

Flashes of superoxide anion (O₂⁻) in mitochondria are generated spontaneously or during the opening of the permeability transition pore (mPTP) and a sudden change in the metabolic state of a cell. Under certain conditions, O₂⁻ can leave the mitochondrial matrix and perform signaling functions beyond mitochondria. In this work, we studied the kinetics of the release of O₂⁻ and H₂O₂ from isolated mitochondria upon mPTP opening and the modulation of the metabolic state of mitochondria by the substrates of respiration and oxidative phosphorylation. It was found that mPTP opening leads to suppression of H₂O₂ emission and activation of the O₂⁻ burst. When the induction of mPTP was blocked by its antagonists (cyclosporine A, ruthenium red, EGTA), the level of substrates of respiration and oxidative phosphorylation and the selective inhibitors of complexes I and V determined the type of reactive oxygen species (ROS) emitted by mitochondria. It was concluded that upon complete and partial reduction and complete oxidation of redox centers of the respiratory chain, mitochondria emit H₂O₂, O₂⁻, and nothing, respectively. The results indicate that the mPTP- and substrate-dependent switching of the type of ROS leaving mitochondria may be the basis for O₂⁻- and H₂O₂-selective redox signaling in a cell. Full article

The diaphragm is the primary muscle of respiration. Here, we disclose a fascinating patient’s perspective that led, by clinical reasoning alone, to a novel mechanism of spontaneous respiratory arrests termed diaphragm cramp-contracture (DCC). Although the 7-year-old boy survived its paroxysmal nocturnal “bearhug pain apnea” episodes, essentially by breathing out to breathe in, DCC could cause sudden unexpected deaths in children, especially infants. Diaphragm fatigue is central to the DCC hypothesis in SIDS. Most, if not all, SIDS risk factors contribute to it, such as male sex, young infancy, rebreathing, nicotine, overheating and viral infections. A workload surge by a roll to prone position or REM-sleep inactivation of airway dilator or respiratory accessory muscles can trigger pathological diaphragm excitation (e.g., spasms, flutter, cramp). Electromyography studies in preterm infants already show that diaphragm fatigue and sudden temporary failure by transient spasms induce apneas, hypopneas and forced expirations, all leading to hypoxemic episodes. By extension, prolonged spasm as a diaphragm cramp would induce sustained apnea with severe hypoxemia and cardiac arrest if not quickly aborted. This would cause a sudden, rapid, silent death consistent with SIDS. Moreover, a unique airway obstruction could develop where the hypercontracted diaphragm resists terminal inspiratory efforts by the accessory muscles. It would disappear postmortem. SIDS autopsy evidence consistent with DCC includes disrupted myofibers and contraction band necrosis as well as signs of agonal breathing from obstruction. Screening for diaphragm injury from hypoxemia, hyperthermia, viral myositis and excitation include serum CK-MM and skeletal troponin-I. Active excitation could be visualized on ultrasound or fluoroscopy and monitored by respiratory inductive plethysmography or electromyography. Full article

Marginal lands have been proposed to produce non-food crop biomass for energy or green materials. For this purpose, the selection, implementation, and growth optimization of plant species on such lands are key elements to investigate to achieve relevant plant yields. Stinging nettle (Urtica dioica) is a herbaceous perennial that grows spontaneously on contaminated lands and was described as suitable to produce fibers for material applications. Two mercury-contaminated soils from industrial wastelands with different properties (grassland soil and sediment landfill) were used in this study to assess the potential growth of stinging nettle in a greenhouse mesocosm experiment. Two organic amendments were studied for their impact on nettle growth. The solid digestate from organic food wastes significantly doubled plant biomass whereas the compost from green wastes had a lower impact. The highest doses of organic amendments significantly increased the number of fibers, which doubled following digestate application, while reducing leaf Hg concentration. Both amendments significantly improved soil respiration and enzymatic activities linked to the microbial biomass in the soil from the sediment landfill by the end of the experiment. In the context of a phytomanagement scenario, solid digestate would be a preferred amendment resource to improve nettle production on industrial wastelands. Full article

The way of disposing of rock mineral material has a significant impact on subsequent spontaneous vegetation succession, soil properties, and respiration. We compared seven spontaneously vegetated samples from a large (2 km²) borrow pit used to dispose of the byproducts of a hard coal mine with seven plots from four coal mine spoil heap piles. We used BIOLOG EcoPlates to assess the microbial catabolic activity of the substrate. The substrate in the borrow pit was characterized by higher water content and lower temperature compared to the heap pile substrate. The borrow pit had a more diverse plant community structure. Higher Rao’s quadratic entropy, functional richness, and functional divergence were also calculated from plant functional traits in borrow pit samples. Although borrow pit samples showed higher total microbial biomass, bacteria/fungi ratio, and gram+/gram− ratio, and heap pile samples showed higher soil enzymatic activity, microbial functional diversity, and catabolic activity, these differences were not significant. Soil respiration from the borrow pit substrate was two folds higher. The borrow pit method of disposing of rock mineral material can be suggested to speed up spontaneous vegetation succession. This research provides new insights into the effects of burying hard coal byproducts in borrow pits and offers guidance for the management of hard coal mining. Full article

In this study, we propose a low-cost piezoelectric flexible pressure sensor fabricated on Kapton^® (Kapton™ Dupont) substrate by using aluminum nitride (AlN) thin film, designed for the monitoring of the respiration rate for a fast detection of respiratory anomalies. The device was characterized in the range of 15–30 breaths per minute (bpm), to simulate moderate difficult breathing, borderline normal breathing, and normal spontaneous breathing. These three breathing typologies were artificially reproduced by setting the expiratory to inspiratory ratios (E:I) at 1:1, 2:1, 3:1. The prototype was able to accurately recognize the breath states with a low response time (~35 ms), excellent linearity (R² = 0.997) and low hysteresis. The piezoelectric device was also characterized by placing it in an activated carbon filter mask to evaluate the pressure generated by exhaled air through breathing acts. The results indicate suitability also for the monitoring of very weak breath, exhibiting good linearity, accuracy, and reproducibility, in very low breath pressures, ranging from 0.09 to 0.16 kPa. These preliminary results are very promising for the future development of smart wearable devices able to monitor different patients breathing patterns, also related to breathing diseases, providing a suitable real-time diagnosis in a non-invasive and fast way. Full article

Background: Due to a lack of randomised controlled trials and guidelines, and only case reports being available in the literature, there is no consensus on how to approach anaesthetic management in patients with giant intraabdominal tumours. Methods: This study aimed to evaluate the literature and explore the current status of evidence, by undertaking an observational research design with a descriptive account of characteristics observed in a case series referring to patients with giant intraabdominal tumours who underwent anaesthesia. Results: Twenty patients diagnosed with giant intraabdominal tumours were included in the study, most of them women, with the overall pathology being ovarian-related and sarcomas. Most of the patients were unable to lie supine and assumed a lateral decubitus position. Pulmonary function tests, chest X-rays, and thoracoabdominal CT were the most often performed preoperative evaluation methods, with the overall findings that there was no atelectasis or pleural effusion present, but there was bilateral diaphragm elevation. The removal of the intraabdominal tumour was performed under general anaesthesia in all cases. Awake fiberoptic intubation or awake videolaryngoscopy was performed in five cases, while the rest were performed with general anaesthesia with rapid sequence induction. Only one patient was ventilated with pressure support ventilation while maintaining spontaneous ventilation, while the rest were ventilated with controlled ventilation. Hypoxemia was the most reported respiratory complication during surgery. In more than 50% of cases, there was hypotension present during surgery, especially after the induction of anaesthesia and after tumour removal, which required vasopressor support. Most cases involved blood loss with subsequent transfusion requirements. The removal of the tumor requires prolonged surgical and anaesthesia times. Fluid drainage from cystic tumour ranged from 15.7 L to 107 L, with a fluid extraction rate of 0.5–2.5 L/min, and there was no re-expansion pulmonary oedema reported. Following surgery, all the patients required intensive care unit admission. One patient died during hospitalization. Conclusions: This study contributes to the creation of a certain standard of care when dealing with patients presenting with giant intraabdominal tumour. More research is needed to define the proper way to administer anaesthesia and create practice guidelines. Full article

Dorsal penile nerve block stands out as one of the commonly employed regional anesthetic techniques in children. Despite the large body of experience, failure rates are still significant. We included 20 children (median (SD) age of 73 (31) months) scheduled for circumcision without general anesthesia and secondary airway manipulation in a consecutive case series. Under ultrasound guidance and utilizing an in-plane needle guidance technique, the dorsal penile nerve block was administered with slight sedation, and spontaneous respiration was maintained in all cases. To investigate the underlying anatomy for dorsal penile nerve blockade, we dissected three cadavers. The primary study endpoint was the success rate of surgical blockade, meaning that the surgical procedure could be performed without additional general anesthesia and invasive airway management. The secondary endpoint was the requirement of analgesics until discharge from the post-anesthesia care unit. The primary endpoint was successfully met in all patients according to our strict definition without additional general anesthesia or airway manipulation. In addition, no child received analgesics until discharge from the recovery room. The anatomical investigation clarified the specific anatomy as baseline knowledge for an ultrasound-guided dorsal penile nerve blockade and enabled successful performance in 20 consecutive children where penile surgery was possible in light sedation without additional airway manipulation. Full article

Background and Objectives: Minimally invasive spine surgery (MISS) under monitored anesthesia care (MAC) has emerged as a treatment modality for spinal radiculopathy. It is essential to secure the airway and guarantee spontaneous respiration without endotracheal intubation during MISS in a prone position. Materials and Methods: To evaluate the feasibility and safety of MAC with dexmedetomidine during MISS, we retrospectively reviewed clinical cases. A retrospective review of medical records was conducted between September 2015 and June 2016. A total of 17 patients undergoing MISS were included. Vital signs were analyzed every 15 min. The depth of sedation was assessed using the bispectral index (BIS) and the frequency of rescue sedatives. Adverse events during anesthesia, including bradycardia, hypotension, respiratory depression, postoperative nausea, and vomiting, were evaluated. Results: All cases were completed without the occurrence of airway-related complications. None of the patients needed conversion to general anesthesia. The median maintenance dosage of dexmedetomidine for adequate sedation was 0.40 (IQR 0.40–0.60) mcg/kg/hr with a median loading dose of 0.70 (IQR 0.67–0.82) mcg/kg. The mean BIS during the main procedure was 76.46 ± 10.75. Rescue sedatives were administered in four cases (23.6%) with a mean of 1.5 mg intravenous midazolam. After dexmedetomidine administration, hypotension and bradycardia developed in six (35.3%) and three (17.6%) of the seventeen patients, respectively. Conclusions: MAC using dexmedetomidine is a feasible anesthetic method for MISS in a prone position. Hypotension and bradycardia should be monitored carefully during dexmedetomidine administration. Full article

Na/K-ATPase (NKA)-mediated regulation of Src kinase, which involves defined amino acid sequences of the NKA α1 polypeptide, has emerged as a novel regulatory mechanism of mitochondrial function in metazoans. Mitochondrial metabolism ensures adequate myocardial performance and adaptation to physiological demand. It is also a critical cellular determinant of cardiac repair and remodeling. To assess the impact of the proposed NKA/Src regulatory axis on cardiac mitochondrial metabolic function, we used a gene targeting approach in human cardiac myocytes. Human induced pluripotent stem cells (hiPSC) expressing an Src-signaling null mutant (A420P) form of the NKA α1 polypeptide were generated using CRISPR/Cas9-mediated genome editing. Total cellular Na/K-ATPase activity remained unchanged in A420P compared to the wild type (WT) hiPSC, but baseline phosphorylation levels of Src and ERK1/2 were drastically reduced. Both WT and A420P mutant hiPSC readily differentiated into cardiac myocytes (iCM), as evidenced by marker gene expression, spontaneous cell contraction, and subcellular striations. Total NKA α1-3 protein expression was comparable in WT and A420P iCM. However, live cell metabolism assessed functionally by Seahorse extracellular flux analysis revealed significant reductions in both basal and maximal rates of mitochondrial respiration, spare respiratory capacity, ATP production, and coupling efficiency. A significant reduction in ROS production was detected by fluorescence imaging in live cells, and confirmed by decreased cellular protein carbonylation levels in A420P iCM. Taken together, these data provide genetic evidence for a role of NKA α1/Src in the tonic stimulation of basal mitochondrial metabolism and ROS production in human cardiac myocytes. This signaling axis in cardiac myocytes may provide a new approach to counteract mitochondrial dysfunction in cardiometabolic diseases. Full article