Unveiling Genetic Diversity Among Bacterial Isolates Using SCoT Markers.

This study aimed to unveil the genetic diversity among 47 bacterial isolates from various species using start codon targeted (SCoT) markers. Six SCoT primers yielded 219 reproducible bands, with 89.04% exhibiting polymorphism. The amplification process generated 28 to 50 fragments per primer, with an average of 36.50. Genetic diversity was quantified using polymorphic information content (PIC) values ranging from 0.11 to 0.14, with SCoT32 showing the highest PIC (0.14) and SCoT23 the lowest (0.11). The resolving power (RP) index, used to assess primer discriminatory power, varied significantly, with SCoT23 demonstrating the highest RP (6.00) and SCoT29 the lowest (4.51). Comparative analysis with conventional markers like M13 and (GTG)5 revealed that certain SCoT primers exhibited superior PIC values, which indicates enhanced utility for interspecies differentiation. The high discrimination level achieved by SCoT primers underscores their effectiveness in genetic differentiation and biodiversity assessment within bacterial populations. This research highlights SCoT markers as powerful tools for microbial genetic studies, which offers valuable insights into bacterial diversity and provides a robust methodological framework for future investigations aimed at elucidating genetic variation and improving species identification. The application of SCoT markers represents a significant advancement in molecular techniques for bacterial characterization and phylogenetic analysis, demonstrating their potential to enhance our understanding of microbial genetics and evolution.

Comparison of mouse models of heart failure with reduced ejection fraction.

AIMS: Heart failure with reduced ejection fraction (HFrEF) is a leading cause of death worldwide; thus, therapeutic improvements are needed. In vivo preclinical models are essential to identify molecular drug targets for future therapies. Transverse aortic constriction (TAC) is a well-established model of HFrEF; however, highly experienced personnel are needed for the surgery, and several weeks of follow-up are necessary to develop HFrEF. To this end, we aimed (i) to develop an easy-to-perform mouse model of HFrEF by treating Balb/c mice with angiotensin-II (Ang-II) for 2 weeks by minipump and (ii) to compare its cardiac phenotype and transcriptome to the well-established TAC model of HFrEF in C57BL/6J mice. METHODS: Mortality and gross pathological data, cardiac structural and functional characteristics assessed by echocardiography and immunohistochemistry and differential gene expression obtained by RNA-sequencing and gene-ontology analyses were used to characterize and compare the two models. To achieve statistical comparability between the two models, changes in treatment groups related to the corresponding control were compared (ΔTAC vs. ΔAng-II). RESULTS: Compared with the well-established TAC model, chronic Ang-II treatment of Balb/c mice shares similarities in cardiac systolic functional decline (left ventricular ejection fraction: -57.25 ± 7.17% vs. -43.68 ± 5.31% in ΔTAC vs. ΔAng-II; P = 0.1794) but shows a lesser degree of left ventricular dilation (left ventricular end-systolic volume: 190.81 ± 44.13 vs. 57.37 ± 10.18 mL in ΔTAC vs. ΔAng-II; P = 0.0252) and hypertrophy (cell surface area: 58.44 ± 6.1 vs. 10.24 ± 2.87 µm2 in ΔTAC vs. ΔAng-II; P < 0.001); nevertheless, transcriptomic changes in the two HFrEF models show strong correlation (Spearman's r = 0.727; P < 0.001). In return, Ang-II treatment in Balb/c mice needs significantly less procedural time [38 min, interquartile range (IQR): 31-46 min in TAC vs. 6 min, IQR: 6-7 min in Ang-II; P < 0.001] and surgical expertise, is less of an object for peri-procedural mortality (15.8% in TAC vs. 0% in Ang-II; P = 0.105) and needs significantly shorter follow-up for developing HFrEF. CONCLUSIONS: Here, we demonstrate for the first time that chronic Ang-II treatment of Balb/c mice is also a relevant, reliable but significantly easier-to-perform preclinical model to identify novel pathomechanisms and targets in future HFrEF research.

Methanogenesis coupled hydrocarbon biodegradation enhanced by ferric and sulphate ions.

Bioremediation provides an environmentally sound solution for hydrocarbon removal. Although bioremediation under anoxic conditions is slow, it can be coupled with methanogenesis and is suitable for energy recovery. By altering conditions and supplementing alternative terminal electron acceptors to the system to induce syntrophic partners of the methanogens, this process can be enhanced. In this study, we investigated a hydrocarbon-degrading microbial community derived from chronically contaminated soil. Various hydrocarbon mixtures were used during our experiments in the presence of different electron acceptors. In addition, we performed whole metagenome sequencing to identify the main actors of hydrocarbon biodegradation in the samples. Our results showed that the addition of ferric ions or sulphate increased the methane yield. Furthermore, the addition of CO2, ferric ion or sulphate enhanced the biodegradation of alkanes. A significant increase in biodegradation was observed in the presence of ferric ions or sulphate in the case of all aromatic components, while naphthalene and phenanthrene degradation was also enhanced by CO2. Metagenome analysis revealed that Cellulomonas sp. is the most abundant in the presence of alkanes, while Ruminococcus and Faecalibacterium spp. are prevalent in aromatics-supplemented samples. From the recovery of 25 genomes, it was concluded that the main pathway of hydrocarbon activation was fumarate addition in both Cellulomonas, Ruminococcus and Faecalibacterium. Chloroflexota bacteria can utilise the central metabolites of aromatics biodegradation via ATP-independent benzoyl-CoA reduction. KEY POINTS: • Methanogenesis and hydrocarbon biodegradation were enhanced by Fe3+ or SO42- • Cellulomonas, Ruminococcus and Faecalibacterium can be candidates for the main hydrocarbon degraders • Chloroflexota bacteria can utilise the central metabolites of aromatics degradation.

Antibacterial efficacy interference of the photocatalytic TiO2 nanoparticle and the lytic bacteriophage vb_EcoS_bov25_1D on the Enterohaemorragic Escherichia coli strain Sakai.

Post-antibiotic era requires the use of alternative pesticides against bacterial infections. One potential application field is agriculture, where pesticides are routinely applied in combinations. In this study we tested the interference of antibacterial effects of two alternative antimicrobials with basically different mode of actions if applied together in vitro by using the Enterohemorrhagic E. coli strain Sakai as a modelorganism, one strain of a pathotype that is frequently associated with meat and plant derived infections. TiO2 is a photocatalytically active nanomaterial, which can generate reactive oxygen species (ROS), exerting destructive effects on macromolecules, while the vb_EcoS_bov25_1D bacteriophage has a specific lytic action. Both, bacteriophages and Sakai were sensitive against ROS if tested separately, during that PFUs of bacteriophages dropped from 5 × 105 to 0 in 4 h, while in case of Sakai CFUs decreased with 5 and 2 logs of magnitude in the presence of 0,05 % and 0,025 % of TiO2 respectively. In Sakai by the sixth minute of ROS exposition the expressions of superoxide dismutases and catalases were boosted, as revealed by whole transcriptomic analyses, but the elevated levels rclC and bshA support some roles of these genes under this stress situation. Combined application of phages and TiO2 under UV-A exposure have revealed that beside the inner enzymatic defence mechanisms presenting phage particles served as shields and spoiled the antimicrobial effect of TiO2 (0,0125 %). As a consequence, phages became sacrificed as during exposition a 3-log drop (5 × 105→5 × 102) in their PFUs was revealed. Survived bacteriophages however in the system remained active and under the subsequent dark phase the 3-log drop in the PFU was compensated in 24 h. Our results show that joint application of the two alternative antimicrobial agents TiO2 and a bacteriophage can have two consequences depending on the circumstances they were used. From one side they complement each other's effects in that TiO2 can exert its effect on UV-A or sunlight exposed areas, whereas the bacteriophage on non-exposed surfaces. On the other hand, they also can spoil each others effect as phages can bind generated ROS and by that protect target bacteria, but bacteria themselves can serve as shields and by that protect phages from the destroying effect of ROS, phages however can exert their antibacterial effects on bacteria.

Novel insights into the modulation of the voltage-gated potassium channel KV1.3 activation gating by membrane ceramides.

Membrane lipids extensively modulate the activation gating of voltage-gated potassium channels (KV), however, much less is known about the mechanisms of ceramide and glucosylceramide actions including which structural element is the main intramolecular target and whether there is any contribution of indirect, membrane biophysics-related mechanisms to their actions. We used two-electrode voltage-clamp fluorometry capable of recording currents and fluorescence signals to simultaneously monitor movements of the pore domain (PD) and the voltage sensor domain (VSD) of the KV1.3 ion channel after attaching an MTS-TAMRA fluorophore to a cysteine introduced into the extracellular S3-S4 loop of the VSD. We observed rightward shifts in the conductance-voltage (G-V) relationship, slower current activation kinetics, and reduced current amplitudes in response to loading the membrane with C16-ceramide (Cer) or C16-glucosylceramide (GlcCer). When analyzing VSD movements, only Cer induced a rightward shift in the fluorescence signal-voltage (F-V) relationship and slowed fluorescence activation kinetics, whereas GlcCer exerted no such effects. These results point at a distinctive mechanism of action with Cer primarily targeting the VSD, while GlcCer only the PD of KV1.3. Using environment-sensitive probes and fluorescence-based approaches, we show that Cer and GlcCer similarly increase molecular order in the inner, hydrophobic regions of bilayers, however, Cer induces a robust molecular reorganization at the membrane-water interface. We propose that this unique ordering effect in the outermost membrane layer in which the main VSD rearrangement involving an outward sliding of the top of S4 occurs can explain the VSD targeting mechanism of Cer, which is unavailable for GlcCer.

Management of Pediatric Superficial Partial-Thickness Burns with Polyhexamethylene Biguanide: Outcomes and Influencing Factors.

Background: In burn care, achieving swift healing with minimal complications remains paramount. This investigation assesses the role of polyhexamethylene biguanide (PHMB) in managing pediatric superficial partial-thickness burns, focusing on the effects of various patient-specific factors on recovery. Methods: Through a retrospective analysis of 27 pediatric cases treated with PHMB, we evaluated the impact of age, burn size, dressing frequency, treatment delay, cold therapy application, and analgesic usage on the time until reepithelialization (TTRE). Results: The majority of patients benefited from early cold therapy, yet only 1 in 3 patients received analgesics. A mean healing time of 8.78 (SD: 2.64) days was observed, with the extent of the burn showing a strong correlation (r: 0.63) to TTRE. Most treatments were managed outpatient, evidenced by a negligible average hospital stay (0.96 days), with recorded no complications. Conclusions: Our findings endorse PHMB as a promising treatment for superficial second-degree burns in young patients, due to the observed stable and rapid wound closure without the association of increased risks. Continued exploration into the optimal application of prehospital interventions and the comprehensive benefits of PHMB in pediatric burn management is necessary. Future research should assess long-term outcomes, including functionality, scar quality, and patient satisfaction.

Treatment options for immune-related adverse events associated with immune checkpoint inhibitors.

The immunotherapy revolution with the use of immune checkpoint inhibitors (ICIs) started with the clinical use of the first ICI, ipilimumab, in 2011. Since then, the field of ICI therapy has rapidly expanded - with the FDA approval of 10 different ICI drugs so far and their incorporation into the therapeutic regimens of a range of malignancies. While ICIs have shown high anti-cancer efficacy, they also have characteristic side effects, termed immune-related adverse events (irAEs). These side effects hinder the therapeutic potential of ICIs and, therefore, finding ways to prevent and treat them is of paramount importance. The current protocols to manage irAEs follow an empirical route of steroid administration and, in more severe cases, ICI withdrawal. However, this approach is not optimal in many cases, as there are often steroid-refractory irAEs, and there is a potential for corticosteroid use to promote tumour progression. This review surveys the current alternative approaches to the treatments for irAEs, with the goal of summarizing and highlighting the best attempts to treat irAEs, without compromising anti-tumour immunity and allowing for rechallenge with ICIs after resolution of the irAEs.

NASH triggers cardiometabolic HFpEF in aging mice.

Both heart failure with preserved ejection fraction (HFpEF) and non-alcoholic fatty liver disease (NAFLD) develop due to metabolic dysregulation, has similar risk factors (e.g., insulin resistance, systemic inflammation) and are unresolved clinical challenges. Therefore, the potential link between the two disease is important to study. We aimed to evaluate whether NASH is an independent factor of cardiac dysfunction and to investigate the age dependent effects of NASH on cardiac function. C57Bl/6 J middle aged (10 months old) and aged mice (24 months old) were fed either control or choline deficient (CDAA) diet for 8 weeks. Before termination, echocardiography was performed. Upon termination, organ samples were isolated for histological and molecular analysis. CDAA diet led to the development of NASH in both age groups, without inducing weight gain, allowing to study the direct effect of NASH on cardiac function. Mice with NASH developed hepatomegaly, fibrosis, and inflammation. Aged animals had increased heart weight. Conventional echocardiography revealed normal systolic function in all cohorts, while increased left ventricular volumes in aged mice. Two-dimensional speckle tracking echocardiography showed subtle systolic and diastolic deterioration in aged mice with NASH. Histologic analyses of cardiac samples showed increased cross-sectional area, pronounced fibrosis and Col1a1 gene expression, and elevated intracardiac CD68+ macrophage count with increased Il1b expression. Conventional echocardiography failed to reveal subtle change in myocardial function; however, 2D speckle tracking echocardiography was able to identify diastolic deterioration. NASH had greater impact on aged animals resulting in cardiac hypertrophy, fibrosis, and inflammation.

Fate of Chiral Symmetries in the Quark-Gluon Plasma from an Instanton-Based Random Matrix Model of QCD.

We propose a new way of understanding how chiral symmetry is realized in the high temperature phase of QCD. Based on the finding that a simple free instanton gas precisely describes the details of the lowest part of the spectrum of the lattice overlap Dirac operator, we propose an instanton-based random matrix model of QCD with dynamical quarks. Simulations of this model reveal that even for small quark mass the Dirac spectral density has a singularity at the origin, caused by a dilute gas of free instantons. Even though the interaction, mediated by light dynamical quarks, creates small instanton-anti-instanton molecules, those do not influence the singular part of the spectrum, and this singular part is shown to dominate Banks-Casher type sums in the chiral limit. By generalizing the Banks-Casher formula for the singular spectrum, we show that in the chiral limit the chiral condensate vanishes if there are at least two massless flavors. Our model also indicates a possible way of resolving a long-standing debate, as it suggests that for two massless quark flavors the U(1)_{A} symmetry is likely to remain broken up to arbitrarily high finite temperatures.

A synthetic flavonoid derivate in the plasma membrane transforms the voltage-clamp fluorometry signal of CiHv1.

Voltage-clamp fluorometry (VCF) enables the study of voltage-sensitive proteins through fluorescent labeling accompanied by ionic current measurements for voltage-gated ion channels. The heterogeneity of the fluorescent signal represents a significant challenge in VCF. The VCF signal depends on where the cysteine mutation is incorporated, making it difficult to compare data among different mutations and different studies and standardize their interpretation. We have recently shown that the VCF signal originates from quenching amino acids in the vicinity of the attached fluorophores, together with the effect of the lipid microenvironment. Based on these, we performed experiments to test the hypothesis that the VCF signal could be altered by amphiphilic quenching molecules in the cell membrane. Here we show that a phenylalanine-conjugated flavonoid (4-oxo-2-phenyl-4H-chromene-7-yl)-phenylalanine, (later Oxophench) has potent effects on the VCF signals of the Ciona intestinalis HV1 (CiHv1) proton channel. Using spectrofluorimetry, we showed that Oxophench quenches TAMRA (5(6)-carboxytetramethylrhodamine-(methane thiosulfonate)) fluorescence. Moreover, Oxophench reduces the baseline fluorescence in oocytes and incorporates into the cell membrane while reducing the membrane fluidity of HEK293 cells. Our model calculations confirmed that Oxophench, a potent membrane-bound quencher, modifies the VCF signal during conformational changes. These results support our previously published model of VCF signal generation and point out that a change in the VCF signal may not necessarily indicate an altered conformational transition of the investigated protein.

Comparative study of the inhalation parameters of COPD patients through NEXThaler® and Ellipta® dry powder inhalers.

The deposition of dry powder aerosol drugs depends on the inhalation parameters of the patients through the inhaler. These data are not directly measured in clinical practice. Their prediction based on the routinely measured spirometric data could help in choosing the appropriate device and optimizing the therapy. The aim of this study was to perform inhalation experiments to find correlations between inhalation parameters of COPD patients through two DPI devices and their native spirometric data, gender, age and disease severity. Another goal was to establish relationships between peak inspiratory flows through NEXThaler® and Ellipta® inhalers and their statistical determinants. Breathing parameters of 113 COPD patients were measured by normal spirometry and while inhaling through the two DPIs. Statistical analysis of the measured data was performed. The average values of peak inspiratory flow through the devices (PIFdev) were 68.4 L/min and 78.0 L/min for NEXThaler® and Ellipta®, respectively. PIFdev values were significantly higher for males than for females, but differences upon age, BMI and disease severity group were not significant. PIFdev values correlated best with their native spirometric counterparts (PIF) and linear relationships between them were revealed. Current results may be used in the future to predict the success of inhalation of COPD patients through DPI devices, which may help in the inhaler choice. By choosing the appropriate device-drug pair for each patient the lung dose can be increased and the efficiency of the therapy improved. Further results of the clinical study will be the subject of a next publication.

Depletion of muscularis macrophages ameliorates inflammation-driven dysmotility in murine colitis model.

Previously, the presence of a blood-myenteric plexus barrier and its disruption was reported in experimentally induced colitis via a macrophage-dependent process. The aim of this study is to reveal how myenteric barrier disruption and subsequent neuronal injury affects gut motility in vivo in a murine colitis model. We induced colitis with dextran sulfate sodium (DSS), with the co-administration of liposome-encapsulated clodronate (L-clodronate) to simultaneously deplete blood monocytes contributing to macrophage infiltration in the inflamed muscularis of experimental mice. DSS-treated animals receiving concurrent L-clodronate injection showed significantly decreased blood monocyte numbers and colon muscularis macrophage (MM) density compared to DSS-treated control (DSS-vehicle). DSS-clodronate-treated mice exhibited significantly slower whole gut transit time than DSS-vehicle-treated animals and comparable to that of controls. Experiments with oral gavage-fed Evans-blue dye showed similar whole gut transit times in DSS-clodronate-treated mice as in control animals. Furthermore, qPCR-analysis and immunofluorescence on colon muscularis samples revealed that factors associated with neuroinflammation and neurodegeneration, including Bax1, Hdac4, IL-18, Casp8 and Hif1a are overexpressed after DSS-treatment, but not in the case of concurrent L-clodronate administration. Our findings highlight that MM-infiltration in the muscularis layer is responsible for colitis-associated dysmotility and enteric neuronal dysfunction along with the release of mediators associated with neurodegeneration in a murine experimental model.

Essential Role of BMP4 Signaling in the Avian Ceca in Colorectal Enteric Nervous System Development.

The enteric nervous system (ENS) is principally derived from vagal neural crest cells that migrate caudally along the entire length of the gastrointestinal tract, giving rise to neurons and glial cells in two ganglionated plexuses. Incomplete migration of enteric neural crest-derived cells (ENCDC) leads to Hirschsprung disease, a congenital disorder characterized by the absence of enteric ganglia along variable lengths of the colorectum. Our previous work strongly supported the essential role of the avian ceca, present at the junction of the midgut and hindgut, in hindgut ENS development, since ablation of the cecal buds led to incomplete ENCDC colonization of the hindgut. In situ hybridization shows bone morphogenetic protein-4 (BMP4) is highly expressed in the cecal mesenchyme, leading us to hypothesize that cecal BMP4 is required for hindgut ENS development. To test this, we modulated BMP4 activity using embryonic intestinal organ culture techniques and retroviral infection. We show that overexpression or inhibition of BMP4 in the ceca disrupts hindgut ENS development, with GDNF playing an important regulatory role. Our results suggest that these two important signaling pathways are required for normal ENCDC migration and enteric ganglion formation in the developing hindgut ENS.

Effect of the Lipid Landscape on the Efficacy of Cell-Penetrating Peptides.

Every cell biological textbook teaches us that the main role of the plasma membrane is to separate cells from their neighborhood to allow for a controlled composition of the intracellular space. The mostly hydrophobic nature of the cell membrane presents an impenetrable barrier for most hydrophilic molecules larger than 1 kDa. On the other hand, cell-penetrating peptides (CPPs) are capable of traversing this barrier without compromising membrane integrity, and they can do so on their own or coupled to cargos. Coupling biologically and medically relevant cargos to CPPs holds great promise of delivering membrane-impermeable drugs into cells. If the cargo is able to interact with certain cell types, uptake of the CPP-drug complex can be tailored to be cell-type-specific. Besides outlining the major membrane penetration pathways of CPPs, this review is aimed at deciphering how properties of the membrane influence the uptake mechanisms of CPPs. By summarizing an extensive body of experimental evidence, we argue that a more ordered, less flexible membrane structure, often present in the very diseases planned to be treated with CPPs, decreases their cellular uptake. These correlations are not only relevant for understanding the cellular biology of CPPs, but also for rationally improving their value in translational or clinical applications.

Non-small cell lung cancer patients treated with Anti-PD1 immunotherapy show distinct microbial signatures and metabolic pathways according to progression-free survival and PD-L1 status.

Due to the high variance in response rates concerning anti-PD1 immunotherapy (IT), there is an unmet need to discover innovative biomarkers to predict immune checkpoint inhibitor (ICI)-efficacy. Our study included 62 Caucasian advanced-stage non-small cell lung cancer (NSCLC) patients treated with anti-PD1 ICI. Gut bacterial signatures were evaluated by metagenomic sequencing and correlated with progression-free survival (PFS), PD-L1 expression and other clinicopathological parameters. We confirmed the predictive role of PFS-related key bacteria with multivariate statistical models (Lasso- and Cox-regression) and validated on an additional patient cohort (n = 60). We find that alpha-diversity showed no significant difference in any comparison. However, there was a significant difference in beta-diversity between patients with long- (>6 months) vs. short (≤6 months) PFS and between chemotherapy (CHT)-treated vs. CHT-naive cases. Short PFS was associated with increased abundance of Firmicutes (F) and Actinobacteria phyla, whereas elevated abundance of Euryarchaeota was specific for low PD-L1 expression. F/Bacteroides (F/B) ratio was significantly increased in patients with short PFS. Multivariate analysis revealed an association between Alistipes shahii, Alistipes finegoldii, Barnesiella visceriola, and long PFS. In contrast, Streptococcus salivarius, Streptococcus vestibularis, and Bifidobacterium breve were associated with short PFS. Using Random Forest machine learning approach, we find that taxonomic profiles performed superiorly in predicting PFS (AUC = 0.74), while metabolic pathways including Amino Acid Synthesis and Fermentation were better predictors of PD-L1 expression (AUC = 0.87). We conclude that specific metagenomic features of the gut microbiome, including bacterial taxonomy and metabolic pathways might be suggestive of ICI efficacy and PD-L1 expression in NSCLC patients.

Medium-Term Results of Staged Laparoscopic Traction Orchiopexy for Intra-abdominal Testes: A Multicenter Analysis.

BACKGROUND: Staged laparoscopic traction orchiopexy (SLTO) is a novel technique for the intra-abdominal testis (IAT) based on elongation of the testicular vessels without separating them. This multicenter study evaluated the medium-term results of this technique. METHODS: Data of SLTO performed in three pediatric surgical centers between 2013 and 2020 were analyzed retrospectively. In 2021, physical and Doppler ultrasound examinations were performed to determine the position and viability of testes. Success was defined as an intra-scrotal testicle without atrophy. RESULTS: SLTO was performed on 48 cases (55 testes, 7 bilateral). Mean age at first stage was 2.9 (0.8-12.6) years. High intra-abdominal testes were found in 16.4% and in 60% morphological abnormalities were observed. To fix the testes to the abdominal wall monofilament suture was used in 67.3%, braided in 29.1%. Mean time between the two stages was 16.4 weeks; three testes required redo traction. Perioperative complications occurred in 21 patients (38.2%) including insufficient fixation (11), testicular atrophy (4), wound complications (4), adhesion of the spermatic cords (1) and hydrocele (1). In case of insufficient fixation monofilament sutures were used in 90.9%. In 2021 38 patients (43 testes) had physical and 36 patients (41 testes) had ultrasound examinations. Mean follow-up was 2.7 (0.34-7.9) years. Altogether five atrophies were identified, and three testicular ascents (7.0%) occurred. The overall success rate was 82.2%. CONCLUSIONS: SLTO may be a feasible alternative to conventional treatments of IATs. Additionally, braided suture seems to be a better option to fix the testicle to the abdominal wall. LEVEL OF EVIDENCE: LEVEL IV.

Comparison of flexible nasogastric tube and semi-rigid catheter during less invasive surfactant administration.

BACKGROUND: Various flexible and semi-rigid catheter techniques have been reported for surfactant delivery during less invasive surfactant administration (LISA) in preterm infants. Data on the effect of catheter selection on procedural success rates and adverse events are limited. Our objective was to compare the rates of success and adverse events of LISA performed with nasogastric tube and semi-rigid catheter. METHODS: This was a post-hoc analysis of data from a quality improvement project. LISA was performed according to the standardized local protocol. Baseline characteristics, data on performance of LISA, degree of difficulty in laryngoscopy and vital parameters after the initiation of LISA were collected and outcomes were compared between groups. RESULTS: Fifty-six infants were included (21 with nasogastric tube, and 35 with semi-rigid catheter). Procedure success rate (defined as a single LISA attempt resulting in intratracheal administration of the planned dose of surfactant), incidence of adverse events, heart rate and oxygen saturation values and outcomes did not differ significantly between the two groups. When using a nasogastric tube for LISA, a significantly higher fraction of inspired oxygen was needed in the 3rd (0.62 vs. 0.48, P=0.024), 4th (0.61 vs. 0.37, P<0.001) and 5th minute (0.48 vs. 0.37, P=0.001) to maintain normal oxygen saturations. CONCLUSIONS: Use of the semi-rigid catheter was associated with better oxygenation during and shortly after the procedure. Our results may help neonatal units to develop local guidelines.

CXCR4 and CXCL12 signaling regulates the development of extrinsic innervation to the colorectum.

The gastrointestinal tract is innervated by an intrinsic neuronal network, known as the enteric nervous system (ENS), and by extrinsic axons arising from peripheral ganglia. The nerve of Remak (NoR) is an avian-specific sacral neural crest-derived ganglionated structure that extends from the cloaca to the proximal midgut and, similar to the pelvic plexus, provides extrinsic innervation to the distal intestine. The molecular mechanisms controlling extrinsic nerve fiber growth into the gut is unknown. In vertebrates, CXCR4, a cell-surface receptor for the CXCL12 chemokine, regulates migration of neural crest cells and axon pathfinding. We have employed chimeric tissue recombinations and organ culture assays to study the role of CXCR4 and CXCL12 molecules in the development of colorectal innervation. CXCR4 is specifically expressed in nerve fibers arising from the NoR and pelvic plexus, while CXCL12 is localized to the hindgut mesenchyme and enteric ganglia. Overexpression of CXCL12 results in significantly enhanced axonal projections to the gut from the NoR, while CXCR4 inhibition disrupts nerve fiber extension, supporting a previously unreported role for CXCR4 and CXCL12 signaling in extrinsic innervation of the colorectum.

Maximum likelihood-based estimation of diffusion coefficient is quick and reliable method for analyzing estradiol actions on surface receptor movements.

The rapid effects of estradiol on membrane receptors are in the focus of the estradiol research field, however, the molecular mechanisms of these non-classical estradiol actions are poorly understood. Since the lateral diffusion of membrane receptors is an important indicator of their function, a deeper understanding of the underlying mechanisms of non-classical estradiol actions can be achieved by investigating receptor dynamics. Diffusion coefficient is a crucial and widely used parameter to characterize the movement of receptors in the cell membrane. The aim of this study was to investigate the differences between maximum likelihood-based estimation (MLE) and mean square displacement (MSD) based calculation of diffusion coefficients. In this work we applied both MSD and MLE to calculate diffusion coefficients. Single particle trajectories were extracted from simulation as well as from α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor tracking in live estradiol-treated differentiated PC12 (dPC12) cells. The comparison of the obtained diffusion coefficients revealed the superiority of MLE over the generally used MSD analysis. Our results suggest the use of the MLE of diffusion coefficients because as it has a better performance, especially for large localization errors or slow receptor movements.