Progression of Amplitude-Integrated Electroencephalography and Neurological Outcomes in Neonates With Hypoxic-Ischemic Encephalopathy: A Single-Institution Cohort Study in Vietnam.

Background The characteristics of amplitude-integrated electroencephalography (aEEG) are associated with neurological outcomes in neonates with hypoxic-ischemic encephalopathy (HIE). We perform a longitudinal analysis of continuous monitoring of aEEG during therapeutic hypothermia and explore the association between aEEG interpretation and clinical neurological outcomes. Method We conducted a prospective cohort study on HIE neonates undergoing hypothermia with aEEG monitoring. Results A total of 37 HIE infants underwent hypothermia with improved aEEG background activity in 28 (75.7%) neonates, of which 18 (48.6%) neonates had background activity returned to a continuous pattern, and the median recovery time was 26.5 hours. Sleep-wake cycle (SWC) appeared in 14 (37.8%) cases, with a median onset time of 34.5 hours. Seizure activity on aEEG was present in 26 (70.3%) infants. Factors associated with poor outcomes at discharge included low voltage or flat trace background activity, a lack of improvement in background activity after hypothermia, and the absence of SWC. Neonates who took longer than 62 hours to return to continuous background activity (time to normal trace) or did not have SWC before the end of hypothermia were more likely to have unfavorable outcomes at discharge. Conclusions Longitudinal analysis of aEEG during hypothermia should be implemented in neonatal care units. The progression of these features on aEEG may predict neurological outcomes for HIE neonates.

Cardiac Tamponade Due to Pericardial Effusion Following Peripherally Inserted Central Catheter: A Single-Institution Case Series.

INTRODUCTION: Although the use of peripherally inserted central catheters (PICCs) has many advantages, misplacement can lead to serious life-threatening complications such as pericardial effusion (PCE) and cardiac tamponade (CT). This report aims to describe four cases of CT resulting from misplaced PICC, which were successfully managed. METHODS: Retrospective analysis of neonates who required PICC insertion and had PCE leading to CT in the Neonatal Intensive Care Unit (NICU) at The Children's Hospital 2, Ho Chi Minh City, Vietnam, during the year 2022. RESULTS: Four cases involved preterm infants at 28-30 weeks gestational age, weighing between 900-1,500 grams. The PCE/CT developed between 3 and 24 days following PICC insertion. The abrupt onset with clinical manifestations that showed hemodynamic instability included sudden deterioration, lethargy, apnea, bradycardia, pale skin, and cardiovascular collapse. We use cardiac point of care ultrasound (POCUS) to assess the condition of these patients and guide the pericardiocentesis procedure. The analysis of the aspirated fluid used for PCE/CT treatment is consistent with the component of parenteral nutrition. No deaths were encountered. CONCLUSION: Neonates presenting sudden deterioration following PICC insertion should undergo POCUS to prompt identifying PCE/CT. Timely diagnosis via POCUS, prompt pericardiocentesis, and prevention of misplaced PICC-associated serious complications are crucial. Monitoring of the PICC position twice a week is recommended to avoid life-threatening complications. Additionally, incorporating POCUS for identifying the tip of PICC rather than relying solely on X-ray should be considered in the current protocol.

Microglial inhibition alleviates alpha-synuclein propagation and neurodegeneration in Parkinson's disease mouse model.

The accumulation of alpha-synuclein (αSyn) is widely recognized as the main pathological process in Parkinson's disease (PD). Additionally, neuroinflammation is considered to be one of the contributing mechanisms in the development of PD. In light of this, it is hypothesized that the reactive microglia exacerbate the propagation of αSyn and neurodegeneration, while the inhibition of microglial activity may mitigate these effects. To test this hypothesis, αSyn preformed fibrils (PFF)-injected PD mouse model was employed. Co-injection of lipopolysaccharide (LPS) and PFF was performed to investigate if microglial reactivity intensified αSyn propagation and neurodegeneration. Additionally, oral administration of PLX5622, a microglial inhibitor that targets the colony-stimulating factor 1 receptor, was given for two weeks before and after PFF injection each to explore if microglial inhibition could prevent or reduce αSyn pathology. Intrastriatal co-injection of LPS and PFF resulted in increased microglial reactivity, αSyn accumulation, and neurodegeneration compared to PFF injection alone. However, treatment with PLX5622 significantly suppressed microglial reactivity, reduced αSyn pathology, and alleviated dopaminergic neuron degeneration in the PD mouse model injected with PFF. Based on these findings, it is evident that microglial reactivity plays a crucial role in the progression of αSyn pathology and neurodegeneration in PD. Furthermore, the results suggest that microglial inhibition may hold promise as a therapeutic strategy to delay the progression of αSyn pathology in PD.

A retrospective study of endogenous endophthalmitis-related pyogenic liver abscess: An increasing complication in North Vietnam.

Introduction: Endogenous endophthalmitis-related Klebsiella pyogenic liver abscess is a rare complication of metastatic infection. In most cases, visual acuity results are often impaired, even blind, and even with aggressive treatment with topical antibiotics, the final results are unsatisfactory. The objective of this study is to retrospectively based on medical records to describe clinical features, risk factors, and visual outcomes of patients with endogenous endophthalmitis-related pyogenic liver abscesses. Methods: We reported a case series of 12 endogenous endophthalmitis-related pyogenic liver abscess patients from March 2021 to 2023. All cases of endogenous endophthalmitis were diagnosed at admission or during the hospital stay. Results: From the medical records of 588 pyogenic liver abscess patients, we found 12 cases of endogenous endophthalmitis with 2.0%. The result showed a mean age of 61.5 ± 12.0 (41-78), diabetes mellitus (7 of 12), right lobe (7 of 12), single abscess (9 of 12), and the mean largest abscess diameter of 5.8 ± 1.7 cm (3.3-9). All patients had ocular symptoms such as eye pain (9 of 12), pus discharge (3 of 12), hypopyon (1 of 12), swollen eyelids (2 of 12), and corneal edema (2 of 12), pyogenic liver abscess before endogenous endophthalmitis (10 of 12), the median interval between endogenous endophthalmitis and pyogenic liver abscess 6.1 ± 1.9 days, ocular symptoms before diagnosis endogenous endophthalmitis 4.4 ± 2.3 days. All affected eyes were injected intravitreously with ceftazidime, amikacin, and vancomycin. Two patients underwent evisceration. Conclusions: Endogenous endophthalmitis has permanent morbidity, reducing visual acuity, poor quality of life, and lacks the warning signs, so it is essential for early detection of symptoms and referral to ophthalmologists.

Prophylaxis of Patent Ductus Arteriosus with Paracetamol in Extremely Low Gestational Age Newborns (ELGANs): A Single-Institution Observational Study in Vietnam.

INTRODUCTION: Prophylactic paracetamol for extremely low gestation age neonates (ELGAN, <27 weeks' gestation) with symptomatic patent ductus arteriosus (sPDA) in high-income countries (HIC) reduces medical and surgical interventions. Its effectiveness in low-to-middle-income countries (LMIC) remains uncertain. This study assesses prophylactic paracetamol's impact on sPDA interventions in ELGANs in an LMIC. METHODS: This is a retrospective cohort study that compared a historical cohort of ELGANs that were treated with oral ibuprofen or intravenous paracetamol after diagnosis of sPDA (n = 104) with infants (n = 76) treated with prophylactic paracetamol (20 mg/kg loading, 7.5 mg/kg qid for 4 days), in a tertiary neonatal intensive care unit (NICU) in Vietnam. Oral ibuprofen or intravenous therapeutic paracetamol were administered if prophylactic paracetamol failed to close sPDA. Surgical ligation was conducted if targeted medical intervention failed, or the infant deteriorated from conditions attributable to sPDA. RESULTS: In the historical cohort, 57 (55%) infants died within 7 days of life compared to 18 (24%) from the prophylactic cohort (p < 0.01). Of the survivors, 21 (45%) of the historical and 23 (39.7%) of the prophylactic cohort required surgical ligation (p = 0.6). Duration of hospitalization for survivors was lower in the prophylactic cohort (mean 74 vs. 97 days, p = 0.01). In the prophylactic cohort, 24 (41%) infants did not need further treatment while 34 (59%) required further treatment including ibuprofen and/or paracetamol 28 (48%) and surgical ligation 22 (38%). CONCLUSIONS: Prophylactic paracetamol for ELGAN in LMIC does not reduce the need for surgical ligation, sPDA rates, and other PDA-related morbidities in infants who survive beyond 7 days of age. It may reduce the risk of death and the duration of hospitalization but further study into the reasons behind this need to be determined with larger studies.

Assessment of technical and clinical utility of a bead-based flow cytometry platform for multiparametric phenotyping of CNS-derived extracellular vesicles.

BACKGROUND: Extracellular vesicles (EVs) originating from the central nervous system (CNS) can enter the blood stream and carry molecules characteristic of disease states. Therefore, circulating CNS-derived EVs have the potential to serve as liquid-biopsy markers for early diagnosis and follow-up of neurodegenerative diseases and brain tumors. Monitoring and profiling of CNS-derived EVs using multiparametric analysis would be a major advance for biomarker as well as basic research. Here, we explored the performance of a multiplex bead-based flow-cytometry assay (EV Neuro) for semi-quantitative detection of CNS-derived EVs in body fluids. METHODS: EVs were separated from culture of glioblastoma cell lines (LN18, LN229, NCH82) and primary human astrocytes and measured at different input amounts in the MACSPlex EV Kit Neuro, human. In addition, EVs were separated from blood samples of small cohorts of glioblastoma (GB), multiple sclerosis (MS) and Alzheimer's disease patients as well as healthy controls (HC) and subjected to the EV Neuro assay. To determine statistically significant differences between relative marker signal intensities, an unpaired samples t-test or Wilcoxon rank sum test were computed. Data were subjected to tSNE, heatmap clustering, and correlation analysis to further explore the relationships between disease state and EV Neuro data. RESULTS: Glioblastoma cell lines and primary human astrocytes showed distinct EV profiles. Signal intensities were increasing with higher EV input. Data normalization improved identification of markers that deviate from a common profile. Overall, patient blood-derived EV marker profiles were constant, but individual EV populations were significantly increased in disease compared to healthy controls, e.g. CD36+EVs in glioblastoma and GALC+EVs in multiple sclerosis. tSNE and heatmap clustering analysis separated GB patients from HC, but not MS patients from HC. Correlation analysis revealed a potential association of CD107a+EVs with neurofilament levels in blood of MS patients and HC. CONCLUSIONS: The semi-quantitative EV Neuro assay demonstrated its utility for EV profiling in complex samples. However, reliable statistical results in biomarker studies require large sample cohorts and high effect sizes. Nonetheless, this exploratory trial confirmed the feasibility of discovering EV-associated biomarkers and monitoring circulating EV profiles in CNS diseases using the EV Neuro assay. Video Abstract.

Extracellular vesicles (EVs) are tiny particles released by cells, carrying unique biomolecules specific to their cell of origin. EVs from the central nervous system (CNS) can reach the blood, where they could serve as liquid-biopsy markers for diagnosing brain diseases like neurodegenerative disorders and tumors. This study evaluated a flow cytometry platform (here termed EV Neuro assay), which can detect multiple EV-associated markers simultaneously, to assess its potential for identifying CNS-derived EVs and disease-specific markers in complex samples including the blood. The study compared different sample materials and methods for isolating EVs. We found distinct EV profiles in EVs derived from glioblastoma and human astrocytes, with signal intensities increasing as more EVs were present. Analyzing serum or plasma from patients with brain diseases and healthy individuals, we observed that EV marker intensities were varying between individuals. Importantly, data normalization improved the identification of disease-specific markers, such as CD36⁺EVs in glioblastoma and GALC⁺EVs in multiple sclerosis, which were significantly higher in disease compared to healthy controls. Advanced clustering analysis techniques effectively distinguished glioblastoma patients from controls. Furthermore, a potential correlation between CD107a⁺EVs and neurofilament levels in multiple sclerosis patients was discovered. Overall, the semi-quantitative EV Neuro assay proved useful for profiling EVs in complex samples. However, for more reliable results in biomarker studies, larger sample cohorts and higher effect sizes are necessary. Nonetheless, this initial trial confirmed the potential of the EV Neuro assay for discovering disease-associated EV markers and monitoring circulating EV profiles in CNS diseases.

The Aging Enteric Nervous System.

The gut and the brain communicate via the nervous system, hormones, microbiota-mediated substances, and the immune system. These intricate interactions have led to the term "gut-brain axis". Unlike the brain-which is somewhat protected-the gut is exposed to a variety of factors throughout life and, consequently, might be either more vulnerable or better adapted to respond to these challenges. Alterations in gut function are common in the elder population and associated with many human pathologies, including neurodegenerative diseases. Different studies suggest that changes in the nervous system of the gut, the enteric nervous system (ENS), during aging may result in gastrointestinal dysfunction and initiate human pathologies of the brain via its interconnection with the gut. This review aims at summarizing the contribution of normal cellular aging to the age-associated physiological changes of the ENS. Morphological alterations and degeneration of the aging ENS are observed in different animal models and humans, albeit with considerable variability. The aging phenotypes and pathophysiological mechanisms of the aging ENS have highlighted the involvement of enteric neurons in age-related diseases of the central nervous system such as Alzheimer's or Parkinson's disease. To further elucidate such mechanisms, the ENS constitutes a promising source of material for diagnosis and therapeutic predictions, as it is more accessible than the brain.

Thermocaproicibacter melissae gen. nov., sp. nov., a thermophilic chain-elongating bacterium, producing n-caproate from polymeric carbohydrates.

Strain MDTJ8T is a chain-elongating thermophilic bacterium isolated from a thermophilic acidogenic anaerobic digestor treating human waste while producing the high commodity chemical n-caproate. The strain grows and produces formate, acetate, n-butyrate, n-caproate and lactate from mono-, di- and polymeric saccharides at 37-60 °C (optimum, 50-55 °C) and at pH 5.0-7.0 (optimum, pH 6.5). The organism is an obligate anaerobe, is motile and its cells form rods (0.3-0.5×1.0-3.0 µm) that stain Gram-positive and occur primarily as chains. Phylogenetic analysis of both the 16S rRNA gene and full genome sequence shows that strain MDTJ8T belongs to a group that consists of mesophylic chain-elongating bacteria within the family Oscillospiraceae, being nearest to Caproicibacter fermentans EA1T (94.8 %) and Caproiciproducens galactitolivorans BS-1T (93.7 %). Its genome (1.96 Mbp) with a G+C content of 49.6 mol% is remarkably smaller than those of other chain-elongating bacteria of the family Oscillospiraceae. Pairwise average nucleotide identity and DNA-DNA hybridization values between strain MDJT8T and its mesophilic family members are less than 70 and 35 %, respectively, while pairwise average amino acid identity values are less than 68 %. In addition, strain MDJT8T uses far less carbohydrate and non-carbohydrate substrates compared to its nearest family members. The predominant cellular fatty acids of strain MDTJ8T are C14 : 0, C14 : 0 DMA (dimethyl acetal) and C16 : 0, while its polar lipid profile shows three unidentified glycophospholipids, 11 glycolipids, 13 phospholipids and six unidentified lipids. No respiratory quinones and polyamines are detected. Based on its phylogenetic, genotypic, morphological, physiological, biochemical and chemotaxonomic characteristics, strain MDTJ8T represents a novel species and novel genus of the family Oscillospiraceae and Thermocaproicibacter melissae gen. nov., sp. nov. is proposed as its name. The type strain is MDTJ8T (=DSM 114174T=LMG 32615T=NCCB 100883T).

Isolation and characterization of a thermophilic chain elongating bacterium that produces the high commodity chemical n-caproate from polymeric carbohydrates.

A thermophilic chain elongating bacterium, strain MDTJ8, was isolated from a thermophilic acidogenic anaerobic digestor producing n-caproate from human waste, growing optimally at 50-55 °C and pH 6.5. 16S rRNA gene analysis suggests that MDTJ8 represents a new species/genus within a group currently composed of mesophilic chain elongators of the Oscillospiraceae family. Genome analysis showed that strain MDTJ8 contains homologues of genes encoding for chain elongation and energy conservation but also indicated n-caproate production from carbohydrates including polymeric substances. This was confirmed by culturing experiments in which MDTJ8 converted, at pH 6.5 and 55 °C, mono-, di- and polymeric carbohydrates (starch and hemicellulose) to n-caproate reaching concentrations up to 283 mg/L and accounting for up to 10 % of the measured fermentation products. MDTJ8 is the first axenic organism that thermophilically performs chain elongation, opening doors to understand and intensify thermophilic bioprocesses targeting anaerobic digestion towards the production of the value-added chemical n-caproate.

Role of NLRP3 Inflammasome in Parkinson's Disease and Therapeutic Considerations.

Parkinson's disease (PD) is the second most common neurodegenerative disease, with two main pathological features: misfolded α-synuclein protein accumulation and neurodegeneration. Inflammation has recently been identified as a contributor to a cascade of events that may aggravate PD pathology. Inflammasomes, a group of intracellular protein complexes, play an important role in innate immune responses to various diseases, including infection. In PD research, accumulating evidence suggests that α-synuclein aggregations may activate inflammasomes, particularly the nucleotide-binding oligomerization domain-leucine-rich repeat-pyrin domain-containing 3 (NLRP3) type, which exacerbates inflammation in the central nervous system by secreting proinflammatory cytokines like interleukin (IL)-18 and IL-1ß. Afterward, activated NLRP3 triggers local microglia and astrocytes to release additional IL-1ß. In turn, the activated inflammatory process may contribute to additional α-synuclein aggregation and cell loss. This review summarizes current research evidence on how the NLRP3 inflammasome contributes to PD pathogenesis, as well as potential therapeutic strategies targeting the NLRP3 inflammasome in PD.

Multiple reassortment and interspecies transmission events contribute to the diversity of porcine-like human rotavirus C strains detected in South Korea.

Globally, rotavirus C (RVC) causes diarrhoeal outbreaks, mainly in swine, with sporadic incidents in human, bovine, and canine populations. In this study, two human RVC strains, RVC/Human-wt/KOR/CAU13-1-77/2013 and RVC/Human-wt/KOR/CAU14-1-242/2014, were isolated in South Korea, and their complete genome sequences were compared with those of other human- and animal-origin RVC strains found worldwide. Genetic analysis revealed that these viruses have a G4-P[2]-I2-R2-C2-M3-A2-N2-T2-E2-H2 genotype constellation. Phylogenetic analysis indicated that these Korean RVC strains belong to the M3 lineage of the VP3 gene in human RVC from Japan and China and porcine RVC from Japan. These results suggest that RVC circulates in northeast Asia in both the human and porcine populations. These results also provide evidence of interspecies RVC reassortment events.

A gene cluster with positive and negative elements controls bistability and hysteresis of the crippled versus normal growth in the fungus Podospora anserina.

The Crippled Growth (CG) cell degeneration of the model ascomycete Podospora anserina (strain S) is controlled by a prion-like element and has been linked to the self-activation of the PaMpk1 MAP kinase cascade. Here, we report on the identification of the "86-11" locus containing twelve genes, ten of which are involved either in setting up the self-activation loop of CG or in inhibiting this loop, as demonstrated by targeted gene deletion. Interestingly, deletion of the whole locus results only in the elimination of CG and in no detectable additional physiological defect. Sequence comparison shows that these ten genes belong to four different families, each one endowed with a specific activity: two encode factors activating the loop, a third one encodes a factor crucial for inhibition of the loop and the fourth one participates in inhibiting the loop in a pathway parallel to the one controlled by the previously described PDC1 gene. Intriguingly, a very distant homologue of this "86-11" locus is present at the syntenic position in Podospora comata (strain T) that do not present Crippled Growth. Introgression of the P. comata strain T locus in P. anserina strain S and the P. anserina strain S in P. comata strain T showed that both drive CG in the P. anserina strain S genetic background, but not in the genetic background of strain P. comata T, indicating that genetic determinants outside the twelve-gene locus are responsible for lack of CG in P. comata strain T. Our data question the role of this twelve-gene locus in the physiology of P. anserina.

PTEN-Induced Putative Kinase 1 Dysfunction Accelerates Synucleinopathy.

BACKGROUND: Mutations in PTEN-induced putative kinase 1 (PINK1) cause autosomal recessive Parkinson's disease (PD) and contribute to the risk of sporadic PD. However, the relationship between PD-related PINK1 mutations and alpha-synuclein (α-syn) aggregation-a main pathological component of PD-remains unexplored. OBJECTIVE: To investigate whether α-syn pathology is exacerbated in the absence of PINK1 after α-syn preformed fibril (PFF) injection in a PD mouse model and its effects on neurodegeneration. METHODS: In this study, 10-week-old Pink1 knockout (KO) and wildtype (WT) mice received stereotaxic unilateral striatal injection of recombinant mouse α-syn PFF. Then, α-syn pathology progression, inflammatory responses, and neurodegeneration were analyzed via immunohistochemistry, western blot analysis, and behavioral testing. RESULTS: After PFF injection, the total α-syn levels significantly increased, and pathological α-syn was markedly aggregated in Pink1 KO mice compared with Pink1 WT mice. Then, earlier and more severe neuronal loss and motor deficits occurred. Moreover, compared with WT mice, Pink1 KO mice had evident microglial/astrocytic immunoreactivity and prolonged astrocytic activation, and a higher rate of protein phosphatase 2A phosphorylation, which might explain the greater α-syn aggravation and neuronal death. CONCLUSION: The loss of Pink1 function accelerated α-syn aggregation, accumulation and glial activation, thereby leading to early and significant neurodegeneration and behavioral impairment in the PD mouse model. Therefore, our findings support the notion that PINK1 dysfunction increases the risk of synucleinopathy.

Inhibition of African swine fever virus replication by ß-glucan.

Background: African swine fever (ASF) is one of the most important diseases in pigs because of its effects on all ages and breeds. To date, commercial vaccines and drugs for the prevention of ASF are lacking in the market and the survival of African swine fever virus (ASFV) in various environmental, farm, and or feed matrices has allowed the virus to remain, causing new outbreaks in the pig population. Besides biosecurity and animal husbandry management practices, the improvement of the host immune responses is critical to control, managing, and preventing ASF. Aim: In this study, we investigated the protective role of ß-glucan against ASFV infection using a porcine alveolar macrophage (PAM) model. Methods: The effects of ß-glucan on cell proliferation were evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The potential effects of ß-glucan against a field ASFV strain isolated in Vietnam were further examined by real-time PCR and hemadsorption assays. The interferon (IFN)-α and interleukin (IL)-6 protein production induced by ß-glucan was determined using a sandwich enzyme-linked immunosorbent assay. Results: Our results demonstrated that the ß-glucan additive possessed an immune stimulus factor against ASFV. Specifically, protection of PAMs against ASFV infection in vitro was observed at 12 hours (p < 0.05) at the tested doses (30 and 50 µg/ml) as induced by incubation with ß-glucan for 2 hours. These effects remained until 24 hours after post-infection. Additionally, at a high dose (50 µg/ml), pre-treatment with the ß-glucan statistically increased the expression levels of IFNα and IL-6 when compared to untreated groups or only ASFV infection. Conclusion: Together, these findings indicated that the ß-glucan may protect the host against ASFV infection via the multiple cellular immune mechanisms.

Corrigendum: Retrospective Analysis of Heartworm (Dirofilia immitis) Prevention Medication Compliance and Economic Value in Dogs in Veterinary Practices in Australia.

[This corrects the article DOI: 10.3389/fvets.2020.602907.].

Temporal Evolution of Inflammation and Neurodegeneration With Alpha-Synuclein Propagation in Parkinson's Disease Mouse Model.

According to a few studies, α-synuclein (αSyn) propagation has been suggested to play a key role in the pathomechanism of Parkinson's disease (PD), but neurodegeneration and the involvement of inflammation in its pathologic progression are not well understood with regard to temporal relationship. In this study, with the help of the PD mouse model injected with intrastriatal αSyn preformed fibril (PFF), the temporal evolution of αSyn propagation, inflammation, and neurodegeneration was explored in the perspective of the striatum and the whole brain. In the PFF-injected striatum, inflammatory response cells, including microglia and astrocytes, were activated at the earliest stage and reduced with time, and the phosphorylated form of αSyn accumulation increased behind it. Afterward, the degeneration of striatal dopaminergic neurons became significant with the conspicuity of behavioral phenotype. Similar patterns of forefront eruption of inflammation and then followed by αSyn propagation were noted in the opposite striatum, which were not injured by PFF injection. In analyzing the whole brain, inflammatory responses were activated at the earliest stage, and the soluble αSyn expression increased concurrently. The inflammatory response decreased afterward, and the accumulation of the insoluble form of αSyn increased behind it. Our results suggested that the inflammatory response may precede the accumulation of the pathologic form of αSyn; thereafter, the neurodegeneration and motor dysfunction followed αSyn proliferation in the PD mouse model. From this model, recognizing the temporal relationship between inflammation, αSyn propagation, and neurodegeneration may be helpful in establishing the PD animal model and monitoring the effect of interventional therapy.

Oxygen for the delivery room respiratory support of moderate-to-late preterm infants. An international survey of clinical practice from 21 countries.

AIM: The aim of this study was to determine clinician opinion regarding oxygen management in moderate-late preterm resuscitation. METHODS: An anonymous online questionnaire was distributed through email/social messaging platforms to neonatologists in 21 countries (October 2020-March 2021) via REDCap. RESULTS: Of the 695 respondents, 69% had access to oxygen blenders and 90% had pulse oximeters. Respondents from high-income countries were more likely to have oxygen blenders than those from middle-income countries (72% vs. 66%). Most initiated respiratory support with FiO2 0.21 (43%) or 0.3 (36%) but only 45% titrated FiO2 to target SpO2 . Most (89%) considered heart rate as a more important indicator of response than SpO2 . Almost all (96%) supported the need for well-designed trials to examine oxygenation in moderate-late preterm resuscitation. CONCLUSION: Most clinicians resuscitated moderate-late preterm infants with lower initial FiO2 but some cannot/will not target SpO2 or titrate FiO2 . Most consider heart rate as a more important indicator of infant response than SpO2 .Large and robust clinical trials examining oxygen use for moderate-late preterm resuscitation, including long-term neurodevelopmental outcomes, are supported amongst clinicians.

Modulation of C-to-T mutation by recombination-independent pairing of closely positioned DNA repeats.

Repeat-induced point mutation is a genetic process that creates cytosine-to-thymine (C-to-T) transitions in duplicated genomic sequences in fungi. Repeat-induced point mutation detects duplications (irrespective of their origin, specific sequence, coding capacity, and genomic positions) by a recombination-independent mechanism that likely matches intact DNA double helices directly, without relying on the annealing of complementary single strands. In the fungus Neurospora crassa, closely positioned repeats can induce mutation of the adjoining nonrepetitive regions. This process is related to heterochromatin assembly and requires the cytosine methyltransferase DIM-2. Using DIM-2-dependent mutation as a readout of homologous pairing, we find that GC-rich repeats produce a much stronger response than AT-rich repeats, independently of their intrinsic propensity to become mutated. We also report that direct repeats trigger much stronger DIM-2-dependent mutation than inverted repeats. These results can be rationalized in the light of a recently proposed model of homologous DNA pairing, in which DNA double helices associate by forming sequence-specific quadruplex-based contacts with a concomitant release of supercoiling. A similar process featuring pairing-induced supercoiling may initiate epigenetic silencing of repetitive DNA in other organisms, including humans.

Recombination-independent recognition of DNA homology for meiotic silencing in Neurospora crassa.

The pairing of homologous chromosomes represents a critical step of meiosis in nearly all sexually reproducing species. In many organisms, pairing involves chromosomes that remain apparently intact. The mechanistic nature of homology recognition at the basis of such pairing is unknown. Using "meiotic silencing by unpaired DNA" (MSUD) as a model process, we demonstrate the existence of a cardinally different approach to DNA homology recognition in meiosis. The main advantage of MSUD over other experimental systems lies in its ability to identify any relatively short DNA fragment lacking a homologous allelic partner. Here, we show that MSUD does not rely on the canonical mechanism of meiotic recombination, yet it is promoted by REC8, a conserved component of the meiotic cohesion complex. We also show that certain patterns of interspersed homology are recognized as pairable during MSUD. Such patterns need to be colinear and must contain short tracts of sequence identity spaced apart at 21 or 22 base pairs. By using these periodicity values as a guiding parameter in all-atom molecular modeling, we discover that homologous DNA molecules can pair by forming quadruplex-based contacts with an interval of 2.5 helical turns. This process requires right-handed plectonemic coiling and additional conformational changes in the intervening double-helical segments. Our results 1) reconcile genetic and biophysical evidence for the existence of direct homologous double-stranded DNA (dsDNA)-dsDNA pairing, 2) identify a role for this process in initiating RNA interference, and 3) suggest that chromosomes can be cross-matched by a precise mechanism that operates on intact dsDNA molecules.

BES1/BZR1 Homolog 3 cooperates with E3 ligase AtRZF1 to regulate osmotic stress and brassinosteroid responses in Arabidopsis.

Proline (Pro) metabolism plays important roles in protein synthesis, redox balance, and abiotic stress response. However, it is not known if cross-talk occurs between proline and brassinosteroid (BR) signaling pathways. Here, an Arabidopsis intergenic enhancer double mutant, namely proline content alterative 41 (pca41), was generated by inserting a T-DNA tag in the Arabidopsis thaliana ring zinc finger 1 (atrzf1 ) mutant background. pca41 had a T-DNA inserted at the site of the gene encoding BES1/BZR1 Homolog 3 (BEH3). pca41 has a drought-insensitive phenotype that is stronger than atrzf1 under osmotic stress, including high Pro accumulation and decreased amounts of reactive oxygen species. Analysis of physiological, genetic, and molecular networks revealed that negative regulation of BEH3 during abiotic stress was linked to the BR signaling pathway. Our data also suggest that AtRZF1, an E3 ubiquitin ligase, might control osmotic stress, abscisic acid, and BR responses in a BEH3-dependent manner. Under darkness, pca41 displays a long hypocotyl phenotype, which is similar to atrzf1 and beh3, suggesting that BEH3 acts in the same pathway as AtRZF1. Overexpression of BEH3 results in an osmotic stress-sensitive phenotype, which is reversed by exogenous BR application. Taken together, our results indicate that AtRZF1 and BEH3 may play important roles in the osmotic stress response via ubiquitination and BR signaling.