Management dilemma in Thoracoamniotic Shunt Migrations.

Shunt migration is a rare but significant complication of thoracoamniotic shunting, an intervention widely used for fetal pleural effusion. We describe a case of a term infant noted antenatally to have fetal hydrothorax that was managed with thoracoamniotic shunting but complicated by shunt migration. We also present the current literature on risk factors, complications and management of intrathoracic shunt migration. The majority of shunt migration cases are managed conservatively with no untoward postnatal sequelae, but surgical removal of the migrated shunt has been used for associated clinical complications, if visceral damage is suspected or if postnatal thoracic surgery is indicated for other reasons. We advocate an approach of conservative management for asymptomatic infants, where possible, to avoid unnecessary surgical and anaesthetic risks to very young, often already compromised children. However, further studies are still required to determine optimal management after shunt migration has occurred to ensure the best outcome.

Selective binding of retrotransposons by ZFP352 facilitates the timely dissolution of totipotency network.

Acquisition of new stem cell fates relies on the dissolution of the prior regulatory network sustaining the existing cell fates. Currently, extensive insights have been revealed for the totipotency regulatory network around the zygotic genome activation (ZGA) period. However, how the dissolution of the totipotency network is triggered to ensure the timely embryonic development following ZGA is largely unknown. In this study, we identify the unexpected role of a highly expressed 2-cell (2C) embryo specific transcription factor, ZFP352, in facilitating the dissolution of the totipotency network. We find that ZFP352 has selective binding towards two different retrotransposon sub-families. ZFP352 coordinates with DUX to bind the 2C specific MT2_Mm sub-family. On the other hand, without DUX, ZFP352 switches affinity to bind extensively onto SINE_B1/Alu sub-family. This leads to the activation of later developmental programs like ubiquitination pathways, to facilitate the dissolution of the 2C state. Correspondingly, depleting ZFP352 in mouse embryos delays the 2C to morula transition process. Thus, through a shift of binding from MT2_Mm to SINE_B1/Alu, ZFP352 can trigger spontaneous dissolution of the totipotency network. Our study highlights the importance of different retrotransposons sub-families in facilitating the timely and programmed cell fates transition during early embryogenesis.

Contemporary Trends in Global Mortality of Sepsis Among Young Infants Less Than 90 Days: A Systematic Review and Meta-Analysis.

Objective: Current knowledge on the global burden of infant sepsis is limited to population-level data. We aimed to summarize global case fatality rates (CFRs) of young infants with sepsis, stratified by gross national income (GNI) status and patient-level risk factors. Methods: We performed a systematic review and meta-analysis on CFRs among young infants < 90 days with sepsis. We searched PubMed, Cochrane Central, Embase, and Web of Science for studies published between January 2010 and September 2019. We obtained pooled CFRs estimates using the random effects model. We performed a univariate analysis at patient-level and a meta-regression to study the associations of gestational age, birth weight, onset of sepsis, GNI, age group and culture-proven sepsis with CFRs. Results: The search yielded 6314 publications, of which 240 studies (N = 437,796 patients) from 77 countries were included. Of 240 studies, 99 were conducted in high-income countries, 44 in upper-middle-income countries, 82 in lower-middle-income countries, 6 in low-income countries and 9 in multiple income-level countries. Overall pooled CFR was 18% (95% CI, 17-19%). The CFR was highest for low-income countries [25% (95% CI, 7-43%)], followed by lower-middle [25% (95% CI, 7-43%)], upper-middle [21% (95% CI, 18-24%)] and lowest for high-income countries [12% (95% CI, 11-13%)]. Factors associated with high CFRs included prematurity, low birth weight, age less than 28 days, early onset sepsis, hospital acquired infections and sepsis in middle- and low-income countries. Study setting in middle-income countries was an independent predictor of high CFRs. We found a widening disparity in CFRs between countries of different GNI over time. Conclusion: Young infant sepsis remains a major global health challenge. The widening disparity in young infant sepsis CFRs between GNI groups underscore the need to channel greater resources especially to the lower income regions. Systematic Review Registration: [www.crd.york.ac.uk/prospero], identifier [CRD42020164321].

Contemporary trends in global mortality of sepsis among young infants less than 90 days old: protocol for a systematic review and meta-analysis.

INTRODUCTION: Neonatal sepsis has a high mortality rate that varies across different populations. We aim to perform a contemporary global evidence synthesis to determine the case fatality rates of neonatal sepsis, in order to better delineate this public health urgency and inform strategies to reduce fatality in this high-risk population. METHODS AND ANALYSIS: We will search PubMed, Cochrane Central, Embase and Web of Science for articles in English language published between January 2010 and December 2019. All clinical trials and observational studies involving infants less than 90 days old with a clinical diagnosis of sepsis and reported case fatality rate will be included. Two independent reviewers will screen the studies and extract data on study variables chosen a priori. Quality of evidence and risk of bias will be assessed using Cochrane Collaboration's tool and ROBINS-I. Results will be synthesised qualitatively and pooled for meta-analysis. ETHICS AND DISSEMINATION: No formal ethical approval is required as there is no collection of primary data. This systematic review and meta-analysis will be disseminated through conference meetings and peer-reviewed publications. PROSPERO REGISTRATION NUMBER: CRD42020164321.

Neurocognitive impairment after neonatal sepsis: protocol for a systematic review and meta-analysis.

INTRODUCTION: The effect of neonatal sepsis on the developing brain is not well documented. We aim to perform evidence synthesis to determine the outcome of neurodevelopmental impairment and intellectual disability among survivors of neonatal sepsis. The data gathered will inform on the long-term neurocognitive outcomes of neonates with sepsis and the measures used to document their developmental disability. METHODS AND ANALYSIS: We will perform a search based on the following parameters: neonates and infants less than 90 days old diagnosed with sepsis who had neurocognitive outcomes or measures of developmental disability reported. We will search PubMed, Cochrane Central, Embase and Web of Science for articles in English language published between January 2010 and December 2019. Clinical trials and observational studies will be included. Two independent reviewers will screen studies for eligibility. Data extraction will then be performed using a standardised form. The quality of evidence and risk of bias will be assessed using Cochrane Collaboration's tool and Risk of Bias in Non-randomised Studies of Intervention (ROBINS-I). The results will be synthesised qualitatively and pooled for meta-analysis. ETHICS AND DISSEMINATION: No formal ethical approval is required as there is no collection of primary data. This systematic review and meta-analysis will be disseminated through conference meetings and peer-reviewed publications. PROSPERO REGISTRATION NUMBER: Registration submitted CRD42020164334.

Global Case-Fatality Rates in Pediatric Severe Sepsis and Septic Shock: A Systematic Review and Meta-analysis.

Importance: The global patterns and distribution of case-fatality rates (CFRs) in pediatric severe sepsis and septic shock remain poorly described. Objective: We performed a systematic review and meta-analysis of studies of children with severe sepsis and septic shock to elucidate the patterns of CFRs in developing and developed countries over time. We also described factors associated with CFRs. Data Sources: We searched PubMed, Web of Science, Excerpta Medica database, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Cochrane Central systematically for randomized clinical trials and prospective observational studies from earliest publication until January 2017, using the keywords "pediatric," "sepsis," "septic shock," and "mortality." Study Selection: Studies involving children with severe sepsis and septic shock that reported CFRs were included. Retrospective studies and studies including only neonates were excluded. Data Extraction and Synthesis: We conducted our systematic review and meta-analysis in close accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled case-fatality estimates were obtained using random-effects meta-analysis. The associations of study period, study design, sepsis severity, age, and continents in which studies occurred were assessed with meta-regression. Main Outcomes and Measures: Meta-analyses to provide pooled estimates of CFR of pediatric severe sepsis and septic shock over time. Results: Ninety-four studies that included 7561 patients were included. Pooled CFRs were higher in developing countries (31.7% [95% CI, 27.3%-36.4%]) than in developed countries (19.3% [95% CI, 16.4%-22.7%]; P < .001). Meta-analysis of CFRs also showed significant heterogeneity across studies. Continents that include mainly developing countries reported higher CFRs (adjusted odds ratios: Africa, 7.89 [95% CI, 6.02-10.32]; P < .001; Asia, 3.81 [95% CI, 3.60-4.03]; P < .001; South America, 2.91 [95% CI, 2.71-3.12]; P < .001) than North America. Septic shock was associated with higher CFRs than severe sepsis (adjusted odds ratios, 1.47 [95% CI, 1.41-1.54]). Younger age was also a risk factor (adjusted odds ratio, 0.95 [95% CI, 0.94-0.96] per year of increase in age). Earlier study eras were associated with higher CFRs (adjusted odds ratios for 1991-2000, 1.24 [95% CI, 1.13-1.37]; P < .001) compared with 2011 to 2016. Time-trend analysis showed higher CFRs over time in developing countries than developed countries. Conclusions and Relevance: Despite the declining trend of pediatric severe sepsis and septic shock CFRs, the disparity between developing and developed countries persists. Further characterizations of vulnerable populations and collaborations between developed and developing countries are warranted to reduce the burden of pediatric sepsis globally.

A Chemically Well-Defined, Self-Assembling 3D Substrate for Long-Term Culture of Human Pluripotent Stem Cells.

Clinical applications of human pluripotent stem cells (PSCs) are limited by the lack of chemically well-defined scaffolds for cell expansion, differentiation, and implantation. In this study, we systematically screened various self-assembling hexapeptides to identify the best matrix for long-term 3D PSC culture. Lysine-containing Ac-ILVAGK-NH2 hydrogels maintained best the pluripotency of human embryonic and induced PSCs even after 30 passages. This peptide matrix is also compatible with the use of xeno-free and defined differentiation media. By exploiting its stimuli-responsive sol-gel transition, arrays of encapsulated PSCs can be bioprinted for large-scale cell expansion and derivation of miniaturized organoid cultures for high-throughput screening.

S-Nitrosylation of Divalent Metal Transporter 1 Enhances Iron Uptake to Mediate Loss of Dopaminergic Neurons and Motoric Deficit.

Elevated iron deposition has been reported in Parkinson's disease (PD). However, the route of iron uptake leading to high deposition in the substantia nigra is unresolved. Here, we show a mechanism in enhanced Fe2+ uptake via S-nitrosylation of divalent metal transporter 1 (DMT1). While DMT1 could be S-nitrosylated by exogenous nitric oxide donors, in human PD brains, endogenously S-nitrosylated DMT1 was detected in postmortem substantia nigra. Patch-clamp electrophysiological recordings and iron uptake assays confirmed increased Mn2+ or Fe2+ uptake through S-nitrosylated DMT1. We identified two major S-nitrosylation sites, C23 and C540, by mass spectrometry, and DMT1 C23A or C540A substitutions abolished nitric oxide (NO)-mediated DMT1 current increase. To evaluate in vivo significance, lipopolysaccharide (LPS) was stereotaxically injected into the substantia nigra of female and male mice to induce inflammation and production of NO. The intranigral LPS injection resulted in corresponding increase in Fe2+ deposition, JNK activation, dopaminergic neuronal loss and deficit in motoric activity, and these were rescued by the NO synthase inhibitor l-NAME or by the DMT1-selective blocker ebselen. Lentiviral knockdown of DMT1 abolished LPS-induced dopaminergic neuron loss.SIGNIFICANCE STATEMENT Neuroinflammation and high cytoplasmic Fe2+ levels have been implicated in the initiation and progression of neurodegenerative diseases. Here, we report the unexpected enhancement of the functional activity of transmembrane divalent metal transporter 1 (DMT1) by S-nitrosylation. We demonstrated that S-nitrosylation increased DMT1-mediated Fe2+ uptake, and two cysteines were identified by mass spectrometry to be the sites for S-nitrosylation and for enhanced iron uptake. One conceptual advance is that while DMT1 activity could be increased by external acidification because the gating of the DMT1 transporter is proton motive, we discovered that DMT1 activity could also be enhanced by S-nitrosylation. Significantly, lipopolysaccharide-induced nitric oxide (NO)-mediated neuronal death in the substantia nigra could be ameliorated by using l-NAME, a NO synthase inhibitor, or by ebselen, a DMT1-selective blocker.

The dosage of Patz1 modulates reprogramming process.

The acquisition of pluripotent cells can be achieved by combined overexpression of transcription factors Oct4, Klf4, Sox2 and c-Myc in somatic cells. This cellular reprogramming process overcomes various barriers to re-activate pluripotency genes and re-acquire the highly dynamic pluripotent chromatin status. Many genetic and epigenetic factors are essentially involved in the reprogramming process. We previously reported that Patz1 is required for maintenance of ES cell identity. Here we report that Patz1 plays an inhibitory role in OKSM-induced reprogramming process since more iPS colonies can be induced from Patz1(+/-) MEFs than wild type MEFs; while the addition of Patz1 significantly repressed reprogramming efficiency. Patz1(+/-) MEFs can surpass the senescence barrier of Ink4a/Arf locus, thus enhancing iPS colonies formation. Moreover, Patz1(+/-) MEFs displayed higher levels of acetylated histone H3, H3K4me2, H3K4me3, H3K36me3 and lower levels of histone H3K9me3 and HP1α, indicating that heterozygous knockout of Patz1 results in a globally open chromatin which is more accessible for transcriptional activation. However, Patz1(-/-) MEFs gave the lowest reprogramming efficiency which may result from cell senescence trigged by up-regulated Ink4a/Arf locus. Together, we have demonstrated that the dosage of Patz1 modulates reprogramming process via significantly influencing cell senescence, proliferation and chromatin structure.

Manipulation of microglial activity as a therapy for Alzheimer's disease.

The review aims to elucidate the potential of microglia as a therapeutic target in alleviating Alzheimer's Disease (AD). Microglia are the resident immune cells in the brain which respond to the presence of the hallmarks of AD, amyloid-beta (A beta) plaques and neurofibrillary tangles (NFT). Activated microglia are able to phagocytose and secrete pro-inflammatory and anti-inflammatory cytokines. However, the eventual accumulation of excess A beta peptides and NFT in AD means that microglial clearance of pathogens has been impaired. Pro-inflammatory cytokines may also contribute to the neurodegeneration. Based on the amyloid cascade hypothesis, A beta-activated microglia can produce pro-inflammatory cytokines which may exacerbate the hyperphosporylation of tau proteins that forms NFT in AD pathology. Microglial activation can thus be manipulated to prevent neurodegeneration and promote neuroprotection through several therapeutic agents and methods. Further studies regarding comprehensive microglial response towards A beta and NFT are required to develop an effective treatment of AD involving microglia.