How DNA is folded and packaged in nucleosomes is an essential regulator of gene expression. Abnormal patterns of chromatin folding are implicated in a wide range of diseases and disorders, including epilepsy and autism spectrum disorder (ASD). These disorders are thought to have a shared pathogenesis involving an imbalance in the number of excitatory-inhibitory neurons formed during neurodevelopment; however, the underlying pathological mechanism behind this imbalance is poorly understood. Studies are increasingly implicating abnormal chromatin folding in neural stem cells as one of the candidate pathological mechanisms, but no review has yet attempted to summarise the knowledge in this field. This meta-synthesis is a systematic search of all the articles on epilepsy, ASD, and chromatin folding. Its two main objectives were to determine to what extent abnormal chromatin folding is implicated in the pathogenesis of epilepsy and ASD, and secondly how abnormal chromatin folding leads to pathological disease processes. This search produced 22 relevant articles, which together strongly implicate abnormal chromatin folding in the pathogenesis of epilepsy and ASD. A range of mutations and chromosomal structural abnormalities lead to this effect, including single nucleotide polymorphisms, copy number variants, translocations and mutations in chromatin modifying. However, knowledge is much more limited into how abnormal chromatin organisation subsequently causes pathological disease processes, not yet showing, for example, whether it leads to abnormal excitation-inhibitory neuron imbalance in human brain organoids.The online version contains supplementary material available at 10.1007/s12035-022-03106-9. Atypical neurodevelopment is increasingly being shown to play a role in the pathogenesis of neurodevelopmental and neurological disorders. Epilepsy and autism spectrum disorder (ASD) provide prototypical examples of this; studies suggest they have a shared pathological aetiology in the form of atypical specification of neural progenitor cells (NPC), which leads to an imbalance in the number of excitatory and inhibitory neurons to form in the adult cortex . HoweverChromatin folding is controlled at multiple scales Fig. , each ofAbnormal patterns of chromatin topology are implicated in the pathogenesis of several diseases. Deletions, duplications and translocations can disrupt normal TAD architecture, causing fusions, shuffling, loss or new TADs to form. This subsequently re-organises regulatory elements into TADs they would not normally be within, which can cause abnormal enhancer-promoter interactions and subsequent ectopic gene expression patterns, a process known as “enhancer hijacking” . Single Question 1: Is abnormal chromatin topology implicated in the pathogenesis of epilepsy or ASD?Question 2: If implicated, how does abnormal chromatin topology contribute to epilepsy or ASD pathogenesis?Abnormalities in chromosome topology are increasingly implicated in ASD and epilepsy; however, no review has yet attempted to synthesise the findings of the literature. Here, we present a meta-synthesis with systematic searching of studies on the role of abnormal chromatin topology in the aetiology of epilepsy and ASD. We seek to answer two primary questions:Where relevant, this review has followed PRISMA guidelines whilst systematically searching for articles, which was performed using the following databases: Web of Science, Medline, Scopus and Embase. The same search criteria (below) were used for each database: AND ("epilepsy" OR "epileptic" OR "seizure" OR "convulsion" OR "autism").Inclusion: primary biological studies (lab-based), peer-reviewed, specific techniques used in study [chromatin confirmation capture (CCC) OR assay for transposable accessibility sequencing (ATAC-seq) OR bulk/single cell RNA sequencing OR super-resolution microscopy], specific results Exclusion: non peer-reviewed, reviews, non-English language, unpublished, no focus on chromatin folding , not open accessThe results were screened by one reviewer using the following inclusion and exclusion criteria:The search identified 274 studies  and large-scale (translocations and copy number variation) mutations of the structural elements themselves. The second concerns mutations of genes that encode proteins with roles in setting up or maintaining the architecture of chromatin topology, or its regulation, such as by epigenetic modifications and action potential cell–cell signalling.Common genetic variants in ASD, identified by genome-wide association studies (GWAS) of cases and controls, have been computationally studied in several papers. In one study, the SNP were mapped either directly to genes or, in those arising in non-coding DNA, their partner genes, which were identified based on chromatin interaction profiles and expression quantitative trait loci . Mapped SLC6A1 due to two de novo point mutations at an intronic enhancer in a neuroblastoma cell line. Interestingly, SLC6A1 is a high-risk gene for both ASD and epilepsy, suggesting its dysregulation by perturbed enhancer function could contribute to epilepsy pathogenesis as well as ASD [DRD2) upon monoallelic, CRISPR-mediated deletion of a downstream, intergenic, promoter-interacting region in iPSC-derived excitatory neurons [Evidence of an association between ASD pathogenesis and perturbed enhancer-promoter interactions has been provided from studies of de novo mutations. In one study, de novo mutations were enriched at distal promoter sites, where transcription factors bind and interactions with enhancers are mediated . More rel as ASD , 3. Thes neurons .Having identified that enhancer dysfunction is a plausible candidate for understanding ASD pathogenesis, a question arises about whether and how commonly non-coding DNA mutations arise at these sites. However, computational analyses indicate they are not very common at these sites. In one study, only two ASD-associated SNP mapped out of 86) to active enhancer regions present in cells of the adult brain . Further6 to actiTogether, these studies show a clear association between ASD-associated single nucleotide polymorphisms and pathological enhancer-promoter interactions. Initial work has helped to provide a pathological link, but further research is needed to show the effect of these mutations and variations on the cellular context, such as whether dysregulated gene expression from perturbed enhancer-promoter dynamics leads to abnormal cell type specification. Further work is also needed to understand if there is a strong association between epilepsy-associated SNP and perturbed enhancer function.cis and trans regulatory elements are a consequence of CNV and a driver of the widespread transcriptomic change. Similar findings come from studies of people with duplication or deletion of the 16p11.2 BP2-BP3 interval, which is associated with an ASD diagnosis, and reduced or increased head circumference size [Duplications and deletions of genomic areas can lead to changes in a gene copy number with local and widespread effects on gene expression and regulation. Several studies of syndromes in which ASD is common have shown this. For example, duplications and deletions of 16p11.2, a common cause of ASD, have been shown to cause widespread transcriptomic changes in lymphoblastoid cells . These tnce size .AUTS2 expression, a high-risk gene for ASD [KCTD7 gene, which is high risk for epilepsy [Although evidence has shown CNV has widespread effects on genome folding, studies suggest the largest effects can occur in the local genomic area of the mutation. Research on 22q11 deletion, which causes DiGeorge syndrome (in which ASD is very common), show prominent changes in the regions flanking the deletion site, affecting CTCF binding patterns and topological domain organisation, as well as the pattern of histone modifications, including for H3K27 acetylation . One con for ASD . Interesepilepsy . It alsoSome of the effects described above, of local and widespread changes in chromosome topology, have been ascribed to the DNA regions targeted by CNV. A computational analysis by Fudenberg showed that structural deletions associated with ASD were enriched at strongly active transcriptional start sites and CTCF binding sites . DeletioIn conclusion, these studies show a clear association between CNV and dysregulated gene expression through altered chromatin topology. However, these were conducted on tissues not pathologically implicated in ASD (lymphoblastoid cells) and do not provide mechanistic proof. Further work is required to show the associations in human neurological tissues, more strongly demonstrate an association for patients with epilepsy, and provide molecular proof of an aetiological mechanism.FOXG1 expression [Translocations leading to changes in chromatin topology have been implicated in ASD and epilepsy pathogenesis. Their presence can cause a loss of normal regulatory elements, which data suggests is one cause of dysregulated pression . This gepression , and abnpression .MEF2C gene are predicted to disrupt TAD boundaries and the activity of its enhancers. This is predicted to cause reduced expression of MEF2C in lymphoblastoid cells of patients with this aberration, as suggested by a change in chromosomal contact data [MEF2C expression is caused in and a main driver of 5q14.3 microdeletion syndrome, in whom epilepsy and ASD-like features are characteristic. In another study of a patient with epilepsy and neurodevelopmental delay, a translocation of chromosomes 15 and 16 juxtaposed heterochromatic and euchromatic areas, which led to a change in the expression of the genes flanking the deletion sites [Reorganisation of local chromatin topology is another effect of translocations that can cause dysregulated gene expression. Balanced translocations of 5q14.3 in regulatory regions of the act data . Decreason sites ; the norLRFN5 gene locus that was not present in the female siblings [LRFN5 is a high risk-of-pathology ASD gene that is located in the middle of a gene desert and large TAD [Sex-specific regulation of chromosome topology is a recent mechanism implicated in ASD pathogenesis. A study of a family with high-functioning ASD males identified a maternally inherited topological haplotype at the siblings . LRFN5 iarge TAD . It was arge TAD .The combined findings of these studies show abnormal chromatin topology due to translocations and sex-specific gene expression regulation are associated with ASD and epilepsy pathogenesis. However, no mechanistic investigation of these associations has been conducted and so the association have not yet been shown to be causal.The previous studies have focused on studying the impact of mutations and alterations of structural elements. However, other mechanisms have also been identified that alter chromatin folding and may contribute to the pathogenesis of epilepsy or ASD.Folding topology of the genome is strongly influenced and controlled by the actions of chromatin regulators. These regulators encompass a wide range of proteins, including transcription factors and chromatin regulators . StudiesPOGZ, a high-risk gene for ASD, showed important roles during mouse neurodevelopment in controlling gene expression patterns, including an enrichment for high-risk ASD genes [POGZ homozygous-deletion mutants showed low levels of ADNP and HP1γ binding in wild-type neurons (compared to upregulated or unchanged genes). Interestingly, POGZ expression-regulated target genes were also enriched for binding by the chromatin regulator CHD8, another high-risk ASD gene [Transcription factors have important roles in regulating chromatin topology, for example, through their effects on chromatin accessibility and enhancer activity . In a stSD genes , 37. TheASD gene . These rMeCP2, which when mutated causes Rett syndrome , plays an essential role in this process [MeCP2 mutations.Another way in which transcription factors control chromosome topology is by mediating the formation of liquid-like phase condensates, for example, in structures like heterochromatin.  process . In mous process . This suResearch has shown that altered epigenetic modifications occur in ASD over genomic areas important for the structural organisation of chromatin. In a post-mortem study of ASD patient brain tissue, it was shown that the DNA 5-hydroxymethylcytosine mark, which controls gene expression patterns, differs across the genome . Most diCHD8 and KDM6B [Many genes mapped as high risk for epilepsy have broad enhancer-like domains (BELD), for which most of their gene body exhibits open chromatin and bears the H3K27 acetylation and H3K4 mono-methylation histone modifications . These gnd KDM6B .Recent data has shown that action potentials received by cortical neurons can rapidly alter the chromosome topology of rapidly transcribed genes as well as induce longer-lasting changes in chromatin loop formation . In a stNPTX2.Neuronal activation in a model of status epilepticus in mice has also shown that synaptic activity leads to acute and chronic topological changes in chromatin folding. In a study by Fernandez-Albert et al., changes were seen over hours and days in neuronal transcriptomes and chromatin accessibility at genes and regulatory elements (including enhancers) . These cThese results show that chromatin topology is altered following seizure-induced activity. It would be interesting to see how the changes in chromosome topology due to seizure activity influence the future patterns of electrical activity in affected brains. Similarly, it would be interesting to see how the chromosome topology of a brain with excitatory-inhibitory imbalance responds to electrical activity as in these experiments, as well as whether mutations in high-risk epilepsy genes alter the normal response in topological re-arrangement following seizure activity.Beyond the focus of this review, the chromatin-based mechanisms discussed in this paper provide numerous therapeutic targets to investigate. This is especially relevant given current anti-epileptic drugs (AED) are known to have wide-spread epigenetic effects . For exaIn addition to therapeutics, further consideration needs be given to environmental influences that are implicated in pathologies with a neurodevelopmental basis and have been shown to alter gene expression patterns . For exaThis review provides strong evidence implicating abnormal chromatin folding in the pathogenesis of epilepsy and ASD. This can be due to small or large scale genetic alterations, or less direct mechanisms like mutations of transcription factors. These pathological processes converge on general mechanisms whose common output is to perturb normal enhancer-promoter contact formation and lead to abnormal gene expression patterns Fig. .Fig. 3AbMuch less mechanistic research has been done to study the pathological consequences and causality of abnormal promoter-enhancer contacts. Initial work has shown that disease-associated SNPs at enhancers can reduce transcription at target genes, whilst other studies have identified that action potentials regulate epigenetic modifications at enhancers in pre-formed chromatin loops . Much more work is required to go beyond these initial insights. For example, what pathological cellular processes arise from the abnormal enhancer-promoter contacts and the aberrant transcription patterns they cause? Answers to these and other questions, using patient-derived brain organoids, are needed to provide new insights into the pathogenesis of epilepsy and ASD. This, in turn, will lead to new insights into how to diagnose and treat these conditions.Supplementary file1 (XLSX 61 KB)Supplementary file2 (DOCX 34 KB)Below is the link to the electronic supplementary material.


Klebsiella pneumoniae, frequently manifesting in hospital-acquired pneumonia with a mortality rate of ~50% even with antimicrobial intervention. We performed transcriptomic analysis of data collected previously from in vitro characterization of both laboratory and clinical isolates which revealed shifts in expression of multiple master metabolic regulators across isolate types. Metabolism has been previously shown to be an effective target for antibacterial therapy, and genome-scale metabolic network reconstructions (GENREs) have provided a powerful means to accelerate identification of potential targets in silico. Combining these techniques with the transcriptome meta-analysis, we generated context-specific models of metabolism utilizing a well-curated GENRE of K. pneumoniae (iYL1228) to identify novel therapeutic targets. Functional metabolic analyses revealed that both composition and metabolic activity of clinical isolate-associated context-specific models significantly differs from laboratory isolate-associated models of the bacterium. Additionally, we identified increased catabolism of L-valine in clinical isolate-specific growth simulations. These findings warrant future studies for potential efficacy of valine transaminase inhibition as a target against K. pneumoniae infection.Infections due to carbapenem-resistant Enterobacteriaceae have recently emerged as one of the most urgent threats to hospitalized patients within the United States and Europe. By far the most common etiological agent of these infections is  This recent surge in CRE-associated infections has been driven primarily by the emergence and dissemination of carbapenemases, a specific type of β-lactamase that has the ability to hydrolyze carbapenems, rendering even carbapenem-class antibiotics ineffective2. A large proportion of these CRE-related infections are due to the Gram-negative bacterium Klebsiella pneumoniae3, with over 50% of K. pneumoniae infections now being resistant to carbapenems in parts of the Eastern Mediterranean and Europe3. As K. pneumoniae has been rapidly acquiring antibiotic resistance and rendering almost all available treatments ineffective, the discovery of new treatment strategies for this bacterial pathogen are critical3.Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as a growing and urgent issue in healthcare facilities around the world, posing a significant threat to public health. Carbapenem antibiotics, currently considered to be the most potent and highly effective class of antimicrobial agents, are often considered a last-resort, reserved specifically for the treatment of severe multidrug-resistant (MDR) bacterial infections4. By identifying those characteristics lost during evolution toward sustained laboratory culture, while remaining conserved across infections, it becomes possible to gain insight into important phenotypes that contribute to successful infection. Furthermore, it has been shown that clinical and laboratory isolates of other bacterial pathogens may also be easily differentiated by distinct metabolic capacities5. Employing this approach for K. pneumoniae, we may highlight “core” metabolic pathways in clinical isolates that may present ideal therapeutic target candidates. Consistent with this strategy, certain elements of metabolism have already been successfully identified as drug targets in bacterial pathogens including other Enterobacteriaceae9.One strategy that has emerged recently is the targeting of elements of virulence or core metabolism that may be too costly for the organism to accumulate mutations in or diminish the ability to manifest disease10. While RNA-seq has become a relatively standard method for characterizing transcription, technical variability, small sample sizes, and sample heterogeneity still exist and may influence study-specific results12. Additional differences in data processing criteria also introduce variability into downstream interpretations14. To account for these factors, meta-analyses of transcriptomic datasets across multiple studies can be performed using a unified curation and analysis pipeline. As such, we assembled 56 publicly available transcriptomes of K. pneumoniae isolates from both the laboratory and clinical profiles during growth in similar media conditions at multiple institutions18. Overall, certain transcriptional patterns varied consistently between clinical and laboratory isolates, and differential expression analysis revealed increased transcription of aminoglycoside degradation and key regulators for histidine utilization among clinical isolates.Changes in bacterial transcription have been used to assess differences in active metabolism with higher resolution than metabolomics screens, as shifts can be traced to specific pathways and gene productsK. pneumoniae (iYL1228)19. GENREs are computational formalisms of the biochemical reactions encoded for in an organism’s genome21. Previously, GENRE-based growth simulations in other pathogens have successfully highlighted novel enzyme targets which were subsequently validated in the laboratory, effectively accelerating research efforts21. Additionally, GENREs can also be utilized to provide improved context for omics data as the network architecture can reveal additive effects of small changes in activity across interconnected pathways22. These network-based analyses enable greater insight into metabolic patterns that correspond with growth under specific conditions, such as during active infection21. We continued the transcriptomic meta-analysis through integration with metabolic network-based investigation which allowed us to discern novel conserved components of K. pneumoniae’s metabolic strategy specific to active infection. Most prominent among these predictions was significantly elevated uptake and utilization of environmental L-valine through the increased activity of an Enterobacteriaceae-specific valine transaminase. This elevated uptake of L-valine was observed across >89% of clinical isolate context-specific models, while nearly entirely absent from models of laboratory strains, supporting the hypothesis of increased importance for survival in vivo. These results also agreed with previous findings that macrophages respond to high concentrations of exogenous valine in order to upregulate phagocytosis and the killing of K. pneumoniae during infection23. Our study highlights the utility of well-curated GENREs integrated with transcriptomic data to accelerate molecular target identification.To further explore possible targets within infection-associated metabolic pathways, we integrated our transcriptomic meta-analysis with a previously published genome-scale metabolic network reconstruction (GENRE) of 24 characterizing either laboratory or clinical isolates of K. pneumoniae. Datasets were considered for meta-analysis if isolates were grown to exponential phase in vitro using LB growth medium at 37 °C, at which point transcriptomic samples were collected and sequenced. This selected standard for transcriptomic samples was still anticipated to be reflective of emergent properties within both laboratory strains and clinical isolates25. Strains that undergo serial passaging, including strains that originated from the clinic, are understood to have many different characteristics when compared to strains which were more recently isolated from a clinical setting27. Therefore, the strains represented throughout this study were classified as laboratory strains if they had undergone serial passaging (defined within this study as having undergone greater than four passages29), whereas strains were classified as clinical isolates if they were recently isolated (having undergone a maximum of four passages) from a clinical setting. As properties characteristic of laboratory strains versus clinical isolates are typically understood to be developed over an extended period of time30. These criteria resulted in 56 total RNA-Seq datasets across four distinct studies; of these datasets, 17 represented laboratory strains17 and 39 represented clinical isolates18 37. Briefly, the transcriptomic data integration method identifies the most cost-effective usage of metabolism to achieve growth that best reflects the cell’s investments into transcription and further prunes inactive reactions36. Using this approach, we generated unique isolate-type-specific models of K. pneumoniae metabolism in rich medium for each of the 56 collected transcriptomes, and assessed the emergent differences in active metabolism , indicating that clinical isolates have a higher potential ability to grow more rapidly. This observation may be explained by the fact that colonizing a host organism presents substantial environmental pressure and encourages rapid growth to ensure the highest probability of colonization. Though it was observed that laboratory strains had potentially evolved metabolic machinery towards faster growth in culture medium, the growth simulations performed here demonstrated that clinical isolates may be able to grow more effectively due to their optimization around environmental pressures.After observing consistent differences conserved across the metabolic models with individually integrated transcriptomes, we then performed a unified analysis within each group  to incorporate all possible strain-level variation into single models of metabolism for each isolate type. We first specified the objective function as biomass for the subsequent analysis. We then iterated through a wide range of minimum objective flux values, assessing the correlation between the transcript abundances and the median reaction flux values during each iteration. From this analysis, the optimum biomass flux threshold value corresponding to the highest transcript-to-model correlation value was selected for both conditions. The two resultant models, being one laboratory strain model and one clinical isolate model, are able to account for the variation captured within each isolate type and the optimal flux distributions that most fit with the transcriptomic investments made by the bacterium. From the corresponding flux distributions, we first measured differences in sampled biomass reaction flux, which is analogous to the growth rate and accounts for biosynthesis of major cellular components Fig. . Strikinp-value = 0.001). This finding was intriguing as it indicated the strain groups are likely adapted for growth in distinct metabolic environments despite simulated growth in the same media conditions. Within-group variation was also significantly greater in clinical isolates . To accomplish this goal, flux sampling of the optimal metabolic solution space was performed exhaustively which resulted in possible activity levels for all reactions in the network that satisfies not only robust growth but also the integrated transcriptome. To focus specifically on differential patterns of core metabolism, we temporarily excluded biomass synthesis reaction components as they remained largely consistent across conditions. Using the reaction flux distributions from this subset of the overall metabolic networks, we performed unsupervised machine learning through non-metric multidimensional scaling (NMDS) of Bray–Curtis dissimilarities Fig. , which ip-value ≪ 0.001). Closer investigation revealed the increased L-valine consumption was due to activity of valine transaminase, which mediates the conversion of L-valine to L-alanine and results in the downstream production and export of acetate  is more highly transcribed in laboratory isolates, downstream enzymes in the valine degradation pathway are more highly transcribed in clinical isolates  was curated using K. pneumoniae strain MGH 78578, the diversity of strains the transcriptomic datasets were gathered from may result in a differing ability for the selected model to fully represent the metabolic activity of each of these strains. Furthermore, while the discordant relationship with higher valine transaminase transcription in laboratory strains yet lower reaction activity is most likely due to increased transcription of functionally related enzymes in clinical isolates, inaccuracies in construction of the GENRE may also be a contributing factor that requires additional curation. Despite these considerations, our analyses demonstrate the strength of systems biology approaches to identify potential metabolic targets against bacterial pathogens.While this study presents several novel insights into the relationship between the metabolism of K. pneumoniae. Future studies may build on the targets identified in this study to investigate the role of L-valine in K. pneumoniae colonization and virulence or amino acid release and utilization by immune cells. Finally, the methods described here may be applied to other recalcitrant bacterial pathogens in the future as a platform for accelerated drug target discovery.Our results indicate that increased valine catabolism is a metabolic phenotype more closely associated with clinical isolates of 45 to ≥Q25, a tool that uses quality and length thresholds to determine the appropriate location to trim the 5’- and 3’- end of reads (Supplementary Table K. pneumoniae MGH 78578 genes (GenBank accession number: CP000647.1) using Bowtie246, a tool for aligning sequencing reads to a designated reference sequence, and screened for optical/PCR duplicate reads with Picard MarkDuplicates47, an algorithm for locating and tagging duplicate reads originating from a single fragment of DNA. Mapping files were converted to human-readable format using SAMtools48, a tool designed to facilitate alignment manipulation in the common Sequence Alignment/Map (SAM) format. Transcript abundances were normalized to both read and target gene lengths then evenly subsampled for equal comparison across conditions.All transcriptomic datasets were obtained from the Sequence Read Archive (SRA) in FASTQ format using the SRA Toolkit. Raw reads were quality trimmed using SickleKlebsiella pneumoniae strain MGH 78578, iYL122837, was obtained from the BiGG Model database49 on 5/21/20. Flux analyses performed in this study utilized cobrapy (v0.22.1)50. Growth simulations were performed using a previously published rich medium in silico formulation51. Gene and reaction essentiality screens were both performed with a minimum objective flux threshold of 1.0% of the optimal value, the commonly accepted threshold for these simulations39. Replicate GENRE transcriptome integration was performed with RIPTiDe (v3.2.3)36 with 0.75 minimum objective flux fraction. RIPTiDe is a tool developed to use both transcriptomic abundances and overall flux parsimony to identify the most cost-effective usage of metabolism while still accurately reflecting the inputted transcriptomic data. To prune the model so that it represents the most focused and biologically feasible metabolic solution space possible, RIPTiDe first sets the objective function to carry near optimal flux. Transcriptomic abundance values are then used to assign linear coefficients to each reaction, prior to performing an optimization of the minimum sum of fluxes. Flux balance analysis is then used to identify the reactions that no longer carry flux, and these reactions are subsequently pruned from the model. Maximum fit RIPTiDe analysis, where all minimum objective flux fractions are iteratively tested to return the model with the best correlation between the context-specific flux reactions and the inputted transcriptomic values, was performed with all transcriptome replicates on the default settings.The GENRE of 52.Statistical analyses were performed in R (v3.2.0). Ordination analysis was accomplished using the vegan package (v2.5.7)Supplemental MaterialSupplementary Table 1Supplementary Table 2Supplementary Table 3Supplementary Table 4Supplementary Table 5Supplementary Table 6


As the COVID-19 pandemic evolves, infection with the Omicron variants has become a serious risk to global public health. Anesthesia providers are often called upon for endotracheal intubations for COVID patients. Expedite and safe intubation can save patient’s life, while minimizing the virus exposure to the anesthesia provider and personnel involved during airway intervention is very important to protect healthcare workers and conserve the medical work force. In this paper, we share clinical experience of using a video-assisted intubating stylet technique combined with a simple plastic sheet barrier placed over the patients’ mouth for tracheal intubation during the Omicron crisis in Taiwan. We demonstrated that the use of an intubating stylet combined with plastic sheet barrier is swift, safe, and accurate in securing the airway in patients with COVID-19. The spread of COVID-19 was temporarily contained by the end of 2021 in Taiwan after many lives were lost since the pandemic started in December 2019 .2 in size) was prepared. Two separate holes were made to accommodate the intubating stylet and suction, respectively, on the drape shown in From 1 April to 30 April 2022, due to hospital-wide Omicron infection, all in-hospital medical routine and elective surgical operations were suspended at our institution, with only emergency and urgent surgical procedures being performed. The surgery volume decreased by 90%. The tracheal intubators were recommended to use optimal barriers against any saliva/mucus spread or spill from patients’ mouths and airways during induction of anesthesia in addition to wearing PPE. All of the following 20 cases in this report were performed by the senior anesthesiologist using the video-assisted intubating stylet technique and plastic drape . A techn2) scheduled to undergo DaVinci robotic-assisted laparoscopic myomectomy and ovarian cystectomy  for emergency laparoscopic appendectomy (The second patient (case B in ndectomy . Anesthendectomy .2) with lung abscess and pulmonary empyema was scheduled to receive video-assisted thoracic surgery (VATS). The patient had suffered from tongue squamous cell carcinoma  and was to receive combined surgical treatment with concurrent chemo-radiation therapy. The pre-operative airway evaluation predicted difficult airway management due to limited mouth-opening (<3 cm), upper lip overbite , and stiff neck secondary to radiation therapy. Copious and thick mucus secretions were seen during airway examination (mination . An 8.0 mination . The int2) with pulmonary empyema (right-side lung) was scheduled for VATS. He also suffered lung adenocarcinoma (cT4N2M1c stage IVB) with brain and bone metastases. The transparent plastic sheet barrier was applied as shown in 2) who had deep cutting injuries over extremities and massive bleeding. Emergency plastic surgery was scheduled under general anesthesia. A piece of plastic sheet barrier was put on before starting tracheal intubation using the Shikani technique. The intubation procedure was smooth, swift, and accurate  to very hesitant (n = 10). Hence, it is recommended that the junior practitioners practice first their airway management skills in a medical simulation center (cadaver-based learning) and a clinical skill training center (mannequin-based learning), and then move to routine anesthesia cases prior to handling patients who may be infected with COVID. Even though the plastic sheet barrier is a good and sensible enclosure to prevent further contaminations from intubation , its true safety and effectiveness is difficult to validate. This same problem has also been brought up for the box-barrier enclosure design [In this article, we present 20 clinical cases in which the video-assisted intubating technique and plastic sheet barrier were used for airway intubation during the April 2022 Omicron surge in Taiwan , HIV, hepatitis, Ebola and others.In conclusion, we demonstrate that the Shikani video-assisted intubating stylet technique with a plastic sheet barrier (together with proper PPE) is a safe and effective method for tracheal intubation during the Omicron and other COVID-19 variants pandemic. We also recommend this method of intubation for all AGMPs where the operator might be exposed to potentially infectious airborne germs, including influenza, tuberculosis, methicillin-resistant


Yellow nail syndrome (YNS) is a rare disorder characterized by the triad of yellow nails, lymphedema and chronic respiratory manifestations. Lymphatic abnormalities are a characteristic finding of YNS. Nevertheless, proof of lymphatic vessel abnormality by direct needle puncture for contrast agent injection is technically challenging because the lymphatic vessels in YNS are dysplastic. Thus, we opted for contrast-enhanced magnetic resonance (MR) lymphangiography with subcutaneous injection in patients suspected of YNS to facilitate easier comprehensive lymphatic vessel visualization. The lymphatic vessels of the thighs were few and barely recognizable, indicating weak flow cranially and lymphatic vessel hypoplasia. These findings were suggestive of dysplasia of the lymphatic vessels. Therefore, MR lymphangiography may be a useful novel diagnostic modality for YNS. Yellow nail syndrome (YNS) is a rare disorder characterized by the triad of yellow nails, lymphedema and chronic respiratory manifestations, which include pleural effusion . Its diaA 70-year-old male was admitted to our hospital because of a cough that persisted for several months and fluid accumulation in the right pleural cavity. He had no previous medical history of malignant disease and supplement or medication use. All nails showed yellow discoloration with delayed growth . He had High-resolution chest-computed tomography showed right pleural effusion and bronchiectasis. In addition, 18-Fluorodeoxyglucose positron emission tomography revealed no uptake within the pleura .He underwent pleuroscopy under local anesthesia to evaluate the pleural lesions and rule out malignant disease. A patchy white pleural thickness was revealed using pleuroscopic findings . The pleLymphatic vessel irregularities have been reported in YNS, and so we first attempted ultrasound-guided intranodal lymphangiography via direct puncture of the inguinal lymph nodes. However, puncturing was technically difficult because of atypical lymph node atrophy. Next, we attempted puncturing the lymphatic vessels from the dorsum of the foot via a skin incision but the vessels were too small. Alternatively, we performed contrast-enhanced MR lymphangiography with subcutaneous injection of 1 ml of a mixture of gadolinium-based contrast medium (Gadoteridol) and 1% lidocaine (Gadoteridol and 1% lidocaine are mixed in a ratio of 9:1) into the dorsum of the foot. We performed four dynamic phase acquisitions at 5, 15, 25 and 35 min after subcutaneous injection. The lymphatic vessels of the thighs were few and barely identifiable, indicating poor flow cranially and lymphatic vessel hypoplasia at 35 min after subcutaneous injection . There wThe patient was treated for YNS with 200 mg per day of clarithromycin and oral vitamin E preparation, but with no therapeutic effect. Eventually, he rapidly became emaciated and developed recurrent aspiration pneumonia. The patient died of respiratory failure 6 months after the diagnosis of YNS.YNS is associated with structural and functional lymphatic system abnormalities . HoweverProof of lymphatic vessel abnormality has been based on a diagnostic technique involving direct puncture of the inguinal lymph nodes or lymphatic vessels of the dorsum of the foot and contrast medium injection , 6. HoweThe examination of contrast-enhanced MR lymphangiography was simple, needing only a subcutaneous injection of MR imaging (MRI) contrast medium into the dorsum of the foot, followed by an MRI scan. The major advantage of contrast-enhanced MR lymphangiography compared with non-enhanced MR lymphangiography is the ability to clearly delineate abnormal lymphatic vessels due to the high spatial and temporal resolution. The pre-contrast sequence was performed in our patient, but lymphatic vessels could not be delineated with a low signal on T1-weighted images. Moreover, MR lymphangiography is preferable to lymphatic scintigraphy as it better depicts lymphatic vessel morphology that gives a more comprehensive picture of vessel abnormalities . RegardiThus, our patient’s lymphatic vessels had various abnormalities, including dilatation and stenosis. There were fewer lymphatic vessels than in healthy subjects, suggesting lymphatic hypoplasia. Only mild edema of the lower extremities was revealed in the physical examination, although lymphangiography exhibited abnormal manifestations. Contrast-enhanced MR lymphangiography can be useful in lymphedema cases that are challenging to diagnose based on clinical findings alone, as in our patient.Definitive diagnosis and treatment of YNS are often challenging, and it is likely underdiagnosed. Lymphatic abnormalities are considered a characteristic finding, and MR lymphangiography may be a useful novel diagnostic modality for YNS. However, further accumulation of cases is needed.The authors declare that they have no conflict of interest.None declared.No ethical approval was needed for this case report.We obtained written informed consent from the wife of the patient after he passed away.None declared.


Ovarian cancer is an aggressive tumor that remains to be the most lethal gynecological malignancy in women. Metabolic adaptation is an emerging hallmark of tumors. It is important to exploit metabolic vulnerabilities of tumors as promising strategies to develop more effective anti-tumor regimens. Tumor cells reprogram the metabolic pathways to meet the bioenergetic, biosynthetic, and mitigate oxidative stress required for tumor cell proliferation and survival. Oxidative phosphorylation has been found to be altered in ovarian cancer, and oxidative phosphorylation is proposed as a therapeutic target for management of ovarian cancer. Herein, we initially introduced the overview of oxidative phosphorylation in cancer. Furthermore, we discussed the role of oxidative phosphorylation and chemotherapeutic resistance of ovarian cancer. The role of oxidative phosphorylation in other components of tumor microenvironment of ovarian cancer has also been discussed. Ovarian cancer is an aggressive tumor that remains to be the most lethal gynecological malignancy in women . ResistaDysregulated cellular energetics are emerging hallmarks of tumors. Tumor occurrence and development requires metabolic reprogramming of tumor cells. Tumor cells reprogram the metabolic pathways to meet the bioenergetic and biosynthetic demands required for tumor cell proliferation and survival . Additiovia four mitochondrial protein complexes, namely NADH-Q oxidoreductase (complex I), succinate-Q reductase (complex II), Q-cytochrome c oxidoreductase (complex III), and cytochrome c oxidase (complex IV), protons are pumped from the mitochondrial matrix into the intermembrane space, which sets up the proton gradient. Complex V (ATP synthase) depends on the gradient to drive ATP generation via via  in tumor cells has remained controversial. As electrons pass through the ETC  via via .  exhibit a spectrum of metabolic and functional profiles in response to environmental stimuli, ranging from a pro-inflammatory and tumor-inhibiting M1-like state to a regulatory and tumor-promoting M2-like state . Metabolvia metabolic shift towards OXPHOS through the mitochondrial pyruvate carrier. This metabolic adaptation by enhancing OXPHOS can reverse terminally exhausted T cells and improve the efficacy to immunotherapy, indicating IL-10/Fc can synergize with other cancer immunotherapies for better clinical outcome , an immunosuppressive subset of CD4+ T cells, maintain immunological homeostasis by enhancing self-tolerance and inhibiting autoimmune responses. Transcription factor Foxp3 is specifically expressed in Treg cells, and its expression is critical for differentiation and suppressive function of Tregs . PreciouTherefore, the dysregulated oxidative energetics of tumor cells represent a metabolic vulnerability that could be exploited to enhance anti-tumor immunity. Metformin alone brings limited therapeutic benefit in highly aggressive tumors, whereas combination of metformin with PD-1 blockade improves anti-tumor effect of T cells . MetformAdipocytes are one of the main stromal cell types in multiple tissues, and thereby regarded as a key player in the TME. The adipocyte-tumor interaction results in metabolic and functional alteration within these cells, thereby promoting tumor development , 44. MorCancer-associated fibroblasts (CAFs) are an essential component of the TME and exhibit diverse functions to regulate tumor growth and metastasis. As such, CAFs are regarded as a promising target for optimizing therapeutic strategies against ovarian cancer. Numerous evidence has proposed that CAFs function as main regulators in shaping tumor metabolism especially through the dysregulation of several metabolic pathways. Thus, it is essential to uncover the mechanism of the CAFs-mediated metabolic shift to character metabolic vulnerabilities of ovarian tumors. ITGB2 promoted glycolysis through PI3K/AKT/mTOR pathways in CAFs and secreted lactate to promote OSCC proliferation by enhancing OXPHOS capacities. Using metformin to target the respiratory complex I could effectively inhibit the pro-proliferative effects of ITGB2-expressing CAFs. Lactate from ITGB2-expressing CAFs was absorbed and metabolized in oral squamous cell carcinoma to generate NADH to fuel tumor proliferation. Targeting respiratory complex I effectively inhibited the pro-proliferative effects of ITGB2 expressing CAFs, further supporting lactate oxidation in oral squamous cell carcinoma .The underlying mechanism of resistance to mitochondrial metabolic targeting agents is complex and dynamic. For instance, it has been demonstrated that BRCA1 deficiency upregulates N-nicotinamide methyltransferase (NNMT), which mediates metabolic reprogramming and sensitizes ovarian tumor cells to mitochondrial metabolic targeting agents. Mechanistically, BRCA1 depletion leads to metabolic adaptation of ovarian tumor cells by reducing mitochondrial respiration and ATP production . Loss ofExploring promising biomarkers for predicting therapeutic response to mitochondrial metabolic targeting agents is essential for precision treatment of ovarian cancer patients. Hig expression of PGC1α and β have been identified as biomarkers to select ovarian cancer patients that are more likely to benefit from metformin monotherapy. . MetformTargeting components of OXPHOS could open new avenues for cancer management. NDUFS1 is a nuclear encoded subunit of respiratory complex I. Xenografts established by CRISPR-Cas9 from NDUFS1−/− cells exhibit inhibited growth rates compared with control groups, making NDUFS1 a suitable target for therapeutic intervention. IACS-10759 inhibits OXPHOS by binding to mitochondrial respiratory complex 1 adjacent to the entrance of the ubiquinone channel to impair ubiquinone function, and is currently in phase I clinical development. Targeting OXPHOS with IACS-10759 inhibits growth of multiple tumor models with high antitumor efficacy .Numerous studies have revealed that OXPHOS is upregulated in some tumors, potentially rendering these tumors more sensitive to OXPHOS inhibition. Targeting OXPHOS has become a great potential option for anti-tumor treatment, and there are multiple studies indicating that OXPHOS inhibition is effective in some specific cancer types. However, specifically targeting one subpopulation may eventually fail and lead to a drug-resistant tumor. Inhibiting OXPHOS may result in selecting highly aggressive glycolytic subpopulations. Therefore, it is necessary to explore synergy between OXPHOS inhibitors and drugs blocking glycolysis. OXPHOS inhibition has been tested effectively in a series of tumor types. Identification of specific cancer types and/or molecular characteristics likely to respond to OXPHOS inhibition is required to enable stratification of patients most likely to benefit from this approach. Finally, combinations with other therapies should be further explored to improve the effect of anti-OXPHOS therapy.YW: Conceptualization and Writing of the first draft. XZ, ZW, HC: Review and Editing. WS: Conceptualization and Review. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The end-stage of the clinical combination of heart failure and kidney disease has become known as cardiorenal syndrome. Adverse consequences related to diabetes, hyperlipidemia, obesity, hypertension and renal impairment on cardiovascular function, morbidity and mortality are well known. Guidelines for the treatment of these risk factors have led to the improved prognosis of patients with coronary artery disease and reduced ejection fraction. Heart failure hospital admissions and readmission often occur, however, in the presence of metabolic, renal dysfunction and relatively preserved systolic function. In this domain, few advances have been described. Diabetes, kidney and cardiac dysfunction act synergistically to magnify healthcare costs. Current therapy relies on improving hemodynamic factors destructive to both the heart and kidney. We consider that additional hemodynamic solutions may be limited without the use of animal models focusing on the cardiomyocyte, nephron and extracellular matrices. We review herein potential common pathophysiologic targets for treatment to prevent and ameliorate this syndrome. In the latter stages of heart failure or kidney disease, the interdependence of these two organ systems has become known as cardiorenal syndrome. Although some mechanisms of the kidney  and heart muscle  dysfunction may be independent of each other, others are dependent. Understanding mechanisms common to injuries of both organ systems has led to critical advances. A review of commonalities, linking renal and myocardial cellular and organ dysfunction will be helpful. We examine mechanisms that contribute to the pathogenesis of myocardial dysfunction with pathophysiologic contributions of obesity, diabetes and kidney disease. Mechanisms of hemodynamic overload, ischemia-related dysfunction, ventricular remodeling, excessive neuro-humoral stimulation, abnormal myocyte calcium cycling, cytokine-induced proliferation of extracellular matrix and accelerated apoptosis are within the scope of this review.Heart failure in patients with diabetic kidney disease is associated with interstitial fibrosis and cross-linking of advanced glycated end products (AGE) between myocardial fibrils and within the glomerular filtration apparatus. There may be an intermediate stage of normal systolic function with abnormal diastolic function that may be associated with an increase in myocardial and renal interstitial matrix collagen as well as the binding of AGE to myofibrils and nephrons. Cardiomyopathy in diabetic patients with diminished kidney function may be present for years before the detection of fibrosis by noninvasive testing , such thVentricular diastole refers to the time between aortic valve closure and mitral valve closure, and in descriptive terms has previously been described as divided into four phases . AttemptCardiomyopathy has been described in type 1 diabetes (DM1) ,6,7,8, h2 of body surface area [Current 10-year risk calculators for cardiovascular disease may not provide measurements of renal function for risk estimation nor do they consider heart failure a defined clinical cardiovascular event . Among 1ace area .Both DM1 and DM2 may be complicated by capillary albumin leakage with sympathetic nervous system activation due to relative hypovolemia. Autonomic neuropathy with unopposed sympathetic nerve stimulation as part of the DM1 cardiorenal complex has been the focus of prior studies ,18,19,20A mouse model, genetically altered to reproduce disruption of the glomerular basement membrane, has been used to study left ventricular diastolic dysfunction . Two intEvidence for ventricular dysfunction increases as renal function decreases even with normal coronary anatomy. Increased pulse pressure associated with left ventricular dysfunction  results Uremic toxin removal by isovolemic hemodialysis improves ejection fraction and fiber shortening without blood pressure or diastolic volume change, demonstrating that these toxins impair myocardial function . Two ureAt each stage of renal dysfunction, the prevalence of cardiac arrhythmias and heart failure increases. In the pre-dialysis phase, fewer arrhythmias were noted among patients with advanced CKD on ambulatory EKG than among hemodialysis patients . Among dLong-term echocardiographic observations of dialysis populations have noted a survival advantage when ejection fractions were greater than 45%  with higPatients with heart failure due to myocardial infarction exhibit diminished utilization of fatty acids until ventricular dysfunction has stabilized. Both myocardium  and injuA previously under-appreciated dysfunction of cardiac muscle calcium signaling involving the tricarboxylic acid cycle is being studied in both humans  and the In kidney failure accumulating strands of collagen with or without cross-linking by AGE cause resistance to relaxation following contraction . Over exInhibition of the renin/angiotensin/aldosterone pathway by ACE inhibitors results in increased expression of bradykinin (BK), which promotes the degradation of collagen b. CollagAlthough the sodium glucose transporter-2 inhibitor (SGLT2i) empagliflozin may be beneficial in the reduction of HFrEF, it was not found to alter the accumulation of collagen in an experimental non-diabetic mouse model . Drugs tObesity and hypertension are closely linked through autonomic centers in the midbrain. The satiety hormone leptin controls appetite in the normal population; leptin resistance is present among obese adults. The center for autonomic nervous system activation, which is hyper-stimulated during cycles of weight gain and under-stimulated during weight loss , is locap = 0.028) [Even among normotensive populations, obesity is associated with excess aldosterone, which stimulates cardiomegaly . Outcome= 0.028) . ACE inh= 0.028) . The res= 0.028) .A high-sucrose or high-fat diet impairs systolic and diastolic function  by reducThe human heart normally generates up to 5 kg of ATP/day, amounting to an expenditure of its complete supply of ATP four times/minute. Fatty acid oxidation accounts for 70% of ATP production; glucose/lactate accounts for 30%. Since oxidation of glucose is more efficient than that of fatty acids, glucose oxidation may be recruited up to 40% of the total in times of cardiac stress. Among numerous steps in insulin post-receptor signaling, the Akt-1 position has a direct inhibitory effect on fatty acid oxidation. Down-regulation of fatty acid oxidation includes inhibition of the effect of carnitine palmitoyl transferase to convey palmitate into mitochondria and increased expression of uncoupling protein, both of which result in the diminution of ATP generation .The chemistry of adipose tissue includes systems for the synthesis of several active participants in hypertension. Excess mineralocorticoid synthesis and excretion appear to accompany obese hypertensive patients in chronic kidney disease stages 2–4 and aging ,95. InhiObesity is characterized by elevated levels of leptin and diminished adiponectin. Following weight loss after bariatric surgery ,104 leveRestriction of movement of misfolded proteins in association with ubiquitin from the cytosol into the endoplasmic reticulum of cardiomyocytes in the process of autophagy may lead to toxic accumulation of proteins in dilated cardiomyopathy with heart failure . Toxic aA recent review illustrates correlations between diabetes and HFpEF, describing a heterogeneous group of phenotypes driven in part by comorbidities . IrrespeWhile leakage of albumin into retinal macula has clinical significance, leakage through microvasculature in the heart and kidney may remain undetected until a more advanced state of disease  at whichAccumulation of advanced glycosylation end products (AGE) occurs with chronic insulin resistance and is associated with impaired ventricular relaxation (stiff ventricle). Simultaneously, renal glomerular filtration may be equally impaired through the same cross-linking of collagen molecules . AttemptHeart failure admissions have been associated with a marker for collagen cross-linking: a low ratio of carboxy-terminal telopeptide to matrix metalloproteinase indicates resistance to collagen degradation by matrix metalloproteinase, resulting in ventricular stiffness . Two AGEp < 0.001) and systole (p < 0.05), suggesting chamber stiffness. The higher A1c group demonstrated an increased incidence of LV hypertrophy, associated with higher blood pressure and increased carotid-femoral pulse wave velocity.Increases in tissue collagen or circulating procollagen result in resistance to cardiac chamber filling or “diastolic stiffness”. Production of AGE resulting from hyperglycemia leads to cross-binding from one collagen branch to another with resistance in diastolic filling and arterial distension. In addition to binding across branches of peptide chains, AGE also attaches to lipids, which can be deposited in the myocardium with toxic effects. Among 125 DM2 study subjects with normal ejection fraction and no cardiovascular disease, matched for age and gender, non-invasive measurements revealed significant differences in cardiac diastolic function and peripheral vascular stiffness . When suIn a nondiabetic left anterior descending artery occlusion porcine model, empagliflozin was compared to control over two months. Empagliflozin caused loss of glucose in the urine, forcing the failing heart to resume preferential oxidation of free fatty acids, ketone bodies, and branched-chain amino acids. Indices of heart failure included increased left ventricular mass, increased LV diastolic volume and increased LV end-systolic volume, decreased ejection volume and contractile reserve with dobutamine, as well as increased circulating levels of normetanephrine, B-natriuretic peptide, and troponin. Myocardial metabolism was monitored by cannulation of the coronary artery and coronary sinus. As glucose uptake decreased with empagliflozin, uptake of free fatty acids, ketone bodies (beta-hydroxy-butyrate), lactate, and branched-chain amino acids increased. Control animals demonstrated increased expression of lactate and pyruvate dehydrogenase, consistent with decreased glucose utilization. Empagliflozin treatment was associated with increased activity of succinyl CoA-oxoacid CoA transferase (key enzyme in ketone body oxidation); adenosine monophosphate kinase (regulator of cell metabolism), and carnitine palmitoyl transferase  .Myocardial energy depletion in diabetes is related to limited microvascular uptake of the substrate and to dysfunction in its utilization . MicrovaAnother area where mechanisms of heart muscle dysfunction may differ for persons with or without a diagnosis of insulin resistance looks at calcium flow following ventricular contraction. Passive ventricular filling requires a resetting of myocyte electrical potential through calcium flow out of the reservoir (sarcoplasmic reticulum). Cardiomyopathy in diabetes is associated with decreased movement of calcium in diastole as demonstrated by studies in the obese Zucker rat model of type 2 diabetes and heart tissue samples of type 2 diabetes patients with preserved ejection fraction congestive heart failure .Given the insidious development and progression of cardiomyopathy, indirect noninvasive quantitation of myocardial contraction and relaxation offers benefit, but requires a better understanding of cardiac physicochemical properties. Compliance measures how well tissue can conform to pressure and is measured as a change in volume/change in pressure. Elasticity, the reciprocal of compliance, describes how well tissue returns to its original shape when pressure is removed. Plasticity refers to the ability of living cardiac tissue to change its state in response to stimuli, depending upon the size, thickness, composition and perfusion of the heart muscle. Not all properties are measurable by available non-invasive testing. Early identification of pathologic changes in these physical properties may lead to early interventions to improve clinical outcomes. Ventricular compliance and elasticity indirectly can be measured noninvasively. Indirect measurement of plasticity, however, remains elusive as it depends upon constituents of wall composition . Attempts to define plasticity through deformation imaging radioisotope scan, magnetic resonance imaging, or positron emission tomography have been only partially successful.Elasticity and contractility were studied in juvenile rats after banding of the pulmonary artery. Female rats survived longer, demonstrating lower levels of right ventricular fibrosis, and lower degrees of expression of the calcium/calcineurin cascade .Diabetes-associated cardiomyopathy likely involves two large proteins, collagen and titin. Collagen, located within the interstitial matrix, can be cross-linked between chains of amino acids by AGE , resulting in resistance to both contractions in systole and relaxation in diastole. Titin, located in the cardiomyocyte sarcolemma, has an I region, capable of extension during ventricular diastolic filling, a property that limits resistance to the rhythm of relaxation/contraction. Energy for diastolic extension of the I band of titin derives from the insulin signaling pathway, involving phosphorylation via phosphatidyl-3-kinase. Decreased phosphorylation of titin through reduced activity of protein kinase G has been attributed to hyperglycemia . InsulinAn important study connects cardiac function in women to diabetic kidney disease . CardiacMineralocorticoid receptor antagonists may also improve cardiac contractility by ATP energy generation within muscle . Female An increase in matrix glycoprotein associated with collagen precedes interstitial fibrosis . During Allopurinol has been reported to improve arterial blood flow through a nitric oxide-dependent endothelial system activated by acetylcholine . This vaThe non-steroidal mineralocorticoid receptor agonist finerinone and SGLT2 inhibitors have shown positive effects on renal and cardiac outcomes in patients with DM2. Investigators now looking at the combination of the two drugs. Investigators studied the effects of a low dose combination of fenerinone and empagliflozin on cardiorenal outcomes in hypertensive and proteinuric transgenic rats (mRen)27Rats2. Endothelial dysfunction was induced by including nitrogen monoxide synthase inhibitor N (ω)-nitro-L-arginine methyl ester in drinking water . All ratA retrospective analysis of 232,656 patients (Get With the Guidelines-Heart Failure) demonstrated that persons with diabetes treated for heart failure remained in hospital longer, were directed to a rehabilitation center more often or were more likely to be readmitted for heart failure within 30 days ,180. A rStudies evaluating cardiovascular safety and efficacy of sodium-glucose transport inhibitors have revealed a lower incidence of cardiovascular events with empagliflozin (EMPA-REG)  and canaRenal proximal tubule losses of glucose, sodium, and fluid with empagliflozin  and dapaThe PARADIGM HF study of DM2 , using tResearchers have examined the effects on preservation of heart muscle anatomy and function by use of GLP-1 receptor agonists versus dpp4 inhibitors in a mouse model of cardiomyopathy in type 2 diabetes. Older mice fed a high-fat diet and subjected to constriction of the aorta develop an increase in ventricular mass/volume by echocardiography as well as increased end-diastolic pressure, eventually cardiac interstitial fibrosis. A very specific inhibitor of dipeptidyl peptidase was associated with all of these outcomes to a modest degree. By contrast, liraglutide produced no such changes . A prosp2 [Investigation into the relationships between left ventricular structure/function and hypertension with or without fluid overload is ongoing. For patients with both hypertension and kidney disease, increased ventricular mass due to obstructive arterial disease is associated with decreased survival . Reducti2 , that is2 ,205. The2  concentr2 . Inhibit2 ,28,29, c2 . A uniqu2 . This is2  with ass2 is associated with better outcomes than a BMI of 20 kg/m2 in the cohort [Diastolic dysfunction by clinical examination, chest x-ray, and transthoracic echocardiography was diagnosed in 11 of 190 (5.8%) candidates for live-donor kidney transplantation . Removale cohort .There is an interest in biomarkers for heart failure in the cardiomyopathy population which usually involved obesity, hypertension, and diabetes. Biomarkers for cell proliferation are associated with HFrEF fraction while biomarkers for HFpEF are associated with inflammation . Patient2, associated with diminished reflex constriction of the pulmonary artery [Cardiac autonomic dysfunction is associated with a more rapid progression of kidney dysfunction ,215. Obey artery .Attempts to reduce systolic blood pressure with interruption of sympathetic nerve signaling either above or below the diaphragm have been reported. Renal sympathetic denervation via renal artery catheter has at times been an effective treatment for selected individuals . CardiacCardiac autonomic function correlates with glomerular filtration rate. The normal balance of parasympathetic/sympathetic innervation accounts for increased heart rate  with increased intrathoracic pressure during inspiration versus decreased heart rate  with decreased intrathoracic pressure during expiration. Increased intrathoracic pressure is associated with decreased venous return to the right ventricle with a reflex increase in rate to sustain blood flow to the brain. Persons with diabetes mellitus (DM) may have loss of parasympathetic innervation resulting in a loss of variation in the length of the R-R interval during the respiratory cycle ,225. DurJust as kidney failure may affect cardiac hemodynamics, failure of the heart to provide adequate flow to the kidney will impair kidney function. Efforts have been made to develop a pathophysiologic taxonomy to classify various types of cardio-renal failure to provide a scaffolding for future research ,229. MetThe ongoing COVID pandemic is associated with a new form of cardiomyopathy not entirely reversible for individuals recovering from infection, usually demonstrating additional complications in the pulmonary or renal systems. Elevated troponin levels at the time of COVID infection may be associated with higher mortality . High ti2 or with acute kidney injury [More work needs to be done to understand this connection. The DARE-19 trial, an investigator-initiated trial, looked at whether dapagliflozin can reduce the incidence of cardiovascular, renal, respiratory complications, all-cause mortality, or improve recovery in 1250 patients hospitalized with COVID-19 but not critically ill on admission. Patients were included if they had one or more cardiometabolic risk factors for complications of COVID-19 and were randomized to dapagliflozin 10 mg or placebo . The risy injury .The pathologic interplay between heart and kidney dysfunction now classified as the cardio-renal syndrome demands a more nuanced understanding of the underlying disruption of common cellular pathways in the myocyte and the kidney . A bette


People who use drugs (PWUD) are at high risk of experiencing indirect harms of measures implemented to curb the spread of COVID-19, given high reliance on services and social networks. This study aimed to document short-term changes in behaviours and health-related indicators among PWUD in Montreal, Canada following declaration of a provincial health emergency in Quebec.We administered a structured rapid assessment questionnaire to members of an existing cohort of PWUD and individuals reporting past-year illicit drug use recruited via community services. Telephone and in-person interviews were conducted in May–June and September–December 2020. Participants were asked to report on events and changes since the start of the health emergency . Descriptive analyses were performed.A total of 227 participants were included . 83% and 41% reported past six-month illicit drug use and injection drug use, respectively. 70% of unstably housed participants reported increased difficulty finding shelter since the start of the health emergency. 48% of opioid agonist treatment recipients had discussed strategies to avoid treatment disruptions with providers; 22% had missed at least one dose. Many participants perceived increased difficulty accessing non-addiction health care services. Adverse changes were also noted in indicators pertaining to income, drug markets, drug use frequency, and exposure to violence; however, many participants reported no changes in these areas. Among persons reporting past six-month injection drug use, 79% tried to access needle-syringe programmes during the health emergency; 93% of those obtained services. 45% tried to access supervised injection sites, of whom 71% gained entry.This snapshot suggests mixed impacts of the COVID-19 pandemic on PWUD in Montreal in the months following declaration of a provincial health emergency. There were signals of increased exposure to high-risk environments as well as deteriorations in access to health services. Pandemic-related measures may have lasting impacts among vulnerable subgroups; continued monitoring is warranted.The online version contains supplementary material is available at 10.1186/s12954-022-00620-w. People who use illicit drugs (PWUD) are particularly vulnerable to experiencing direct and indirect harms of the COVID-19 pandemic , 3. PWUDTo mitigate some of the anticipated consequences of the COVID-19 pandemic on PWUD, Canadian health authorities facilitated adaptations to existing services  and implemented emergency measures (e.g. makeshift shelters) following health emergency declarations in the provinces and territories –9. NeverPrior research suggests that events causing widespread disruption (“Big Events”)  carry acDuring that same period, we initiated a rapid assessment study to document short-term impacts of the pandemic on the health and well-being of PWUD in Montreal. Specific aims were to characterize (1) COVID-19 knowledge, concerns, and potential exposure; (2) changes in ability to meet health- and survival-related needs; (3) changes to drug use patterns and risk environments including drug markets; (4) adverse health events and drug-related risk behaviours during the pandemic. We report findings on the latter three aims relating to indirect impacts.The rapid assessment study was initiated in May 2020. We contacted current members of a long-standing cohort study of people who inject drugs (PWID) in Montreal (HEPCO)  and addiA structured questionnaire was developed with reference to a systematic review of health needs assessments in disaster contexts . Unless Institutional review board approval was obtained at the Centre Hospitalier de l’Université de Montréal (CHUM). Study staff were experienced in interviewing members of this population, as they were implicated in other projects within the research team. The rapid design of the study precluded extensive piloting and revision of the questionnaire; however, a short training period allowed interviewers to practise questionnaire administration and understand how to code responses. Interviews were conducted in compliance with sanitary measures in effect at the time. Given lockdown restrictions, data collection in May–June 2020 was limited to telephone interviews with HEPCO participants; verbal informed consent was required. Interviews conducted from September to December 2020 could take place remotely or on-site at the CHUM or within community services. Participants in the latter setting had the option to borrow a study phone to communicate with interviewers. Participants received 20$ CAD as compensation for their time.Descriptive statistics were computed, restricting to relevant subgroups where indicated to aid interpretation .Of 405 HEPCO participants with available contact information, 129 completed the rapid assessment questionnaire . An additional 99 participants were recruited via community services. The current analytic sample excludes one participant who terminated the interview soon after starting, and duplicate data from a participant mistakenly interviewed twice. Table One-third of the sample had experienced a change in living situation since the start of the health emergency. While 36% qualified this as a change for the worse, almost half reported an improvement. Almost one-fifth of the overall sample said they had become homeless because of the pandemic. A majority of participants reporting recent unstable housing  had become harder to access. Of 69 participants receiving opioid agonist treatment (OAT) at the time of their study interview, approximately half had discussed strategies to maintain treatment continuity with their provider(s)  tried to access drug/alcohol treatment during the health emergency, and just half of these were able to receive services. Among people reporting past six-month injection drug use (N = 94), 79% tried to access needle-syringe programmes, the majority of whom (93%) were able to obtain services/materials. 45% tried to access SIS, of whom 71% were able to gain entry. 18% and 23% tried to access naloxone and drug checking, respectively, of whom over 90% were able to obtain services.Few participants (Many participants reported increased frequencies of witnessing (41%) or experiencing (29%) physical violence and experiencing police harassment (21%) since the start of the health emergency, with smaller numbers reporting decreases across these indicators (6–8%). 38% of the sample perceived an increased presence of fentanyl in the drug supply, while 19% had heard of substances newly available on the market. 42% and 70% reported no change in their overall use of non-injection and injection drugs, respectively. Increases and decreases in injection drug use were reported with similar frequency, whereas slightly more participants increased versus decreased their non-injection drug use.Among participants reporting an illicit drug as their most frequently used substance during the last six months, approximately half reported no change in the availability, price, or quality of that drug, while 33–42% perceived negative impacts in these areas. One-quarter reported increased difficulty obtaining credit from dealers. Of those perceiving any such change(s) in the drug market, over one-third reported that these had influenced which drugs they consumed and/or how they consumed them (further details in table).Almost half the sample reported having bought drugs from a new dealer since the start of the health emergency. Frequency of injecting drugs alone, injecting drugs in public, and experiencing withdrawal remained largely unchanged, while 59% reported increases in feelings of depression/anxiety.This rapid assessment study documented short-term impacts of the COVID-19 pandemic on PWUD in Montreal, Canada, focusing on perceptions and experiences following the declaration of a public health emergency in Quebec in March 2020. The study, which collected data up to December 2020, has relevance for pandemic response planning given the paucity of literature examining the impacts of such crises on PWUD through primary data collection .Previous studies assessing outcomes of other events causing widespread disruption  have identified important adverse impacts on drug markets, service provision, drug use patterns, and drug-related risk behaviours and harms . ImpactsWe discuss specific findings with reference to our previously developed conceptual model outlining hypothesized consequences of the COVID-19 pandemic on PWUD, based on evidence from other “Big Events” . Access to supervised injection sites, naloxone, and drug checking appeared sub-optimal. In contrast, participants on OAT were generally able to access their treatment, and needle-syringe programme access appeared high. Anecdotal evidence suggests, however, that the provision side was heavily affected, particularly in the immediate aftermath of the declaration, with certain harm reduction sites temporarily closing or severely limiting operations. Furthermore, although access among OAT enrollees appeared adequate, we did not estimate changes in the rate of OAT initiation in individuals with opioid use disorder, an important outcome for future longitudinal research. Service side administrative data may shed further light on these trends.The study questionnaire only assessed harm reduction service access during the health emergency  appeared minimal when participants were asked to compare the time since the start of the health emergency to their usual situation.The Big Events conceptual model developed for COVID-19 did not outline possible impacts on non-addiction health care services (e.g. emergency departments), which are nevertheless frequently utilized by PWUD , and werA key takeaway from the study is that the COVID-19 pandemic has had variable impacts on PWUD in Montreal. Though we documented adverse effects on housing, income, drug markets and perceived access to health services, many respondents also reported experiencing little to no change in these areas. It is important to note that this perceived lack of change does not necessarily signify a lack of need for support during this and other Big Events; rather, it may signify that PWUD are often navigating difficult circumstances, including precarious housing and income, as well as environments where their physical presence is not welcome. The COVID-19 pandemic may not have been as strongly disruptive among PWUD as it has been for the general population. Instead, as suggested in recent qualitative work , it may Given the negative outcomes documented among certain subgroups, it is crucial that the diversity of drug-using populations be considered during disaster responses, and that adaptations to services be rapid and guided by detailed response plans. Approaches should be tailored to reach the most vulnerable, who may not have the social or financial capital  to acceA critical area of vulnerability that requires greater consideration in such plans is housing instability, which is common among PWUD. In the case of respiratory infection pandemics such as COVID-19, reduced capacity in shelters due to crowding concerns, and reduced opportunities for informal arrangements due to social distancing measures, may lead to increased exposure to street-based environments consistently associated with high-risk behaviours and harms. Housing action plans which consider substance use, and novel Housing First approaches which co-situate mental and physical health supports, are urgently needed, as they directly modify the underlying risk environments known to drive harms among PWUD . InitiatSocioeconomic instability due to decreased income generation opportunities, and shifting drug markets due to changes in global drug trafficking , may alsFinally, health care service disruptions and reorganizations, including longer-term shifts towards telehealth, may disproportionally threaten the overall health of PWUD by setting back efforts to screen for, treat and eliminate hepatitis C virus in this population , 44, in PWUD constitute a “hidden” group; no sampling frame is available to recruit members of this population. Our convenience sample may therefore not represent all PWUD in Montreal, nor PWUD from other urban settings with different drug use and sociodemographic profiles. Samples sizes for some subgroups of PWUD (e.g. OAT recipients) were small. Findings may reflect subjective perceptions or secular trends in events. The study was conducted against an ever-evolving backdrop of public health restrictions. As such, findings constitute a snapshot of experiences in the months following the declaration of a health emergency in Quebec and may underestimate acute impacts felt in its immediate aftermath. Furthermore, the impacts of curfew measures implemented after our study (from January to May 2021) are unclear. Service access during peak (post-curfew) hours and the policing of service seekers were major concerns during that period , 46.The current snapshot suggests mixed impacts of the COVID-19 pandemic on PWUD in Montreal, with signals of increased exposure to high-risk environments and deteriorations in access to health services and housing. Changes were not experienced uniformly by all PWUD. Continuity of low-threshold service provision and in-person interactions may be critical to ensure survival among the most vulnerable. Measures to curb COVID-19 spread may have lasting drug-related harms even once they are lifted; continued monitoring, and greater consideration of the structural drivers of these harms, is warranted.Additional file 1. PDF document containing the following supplementary figures & tables: Figure S1. Satisfaction with adaptations made by pharmacy/medical team to deliver OAT during the health emergency; Figure S2. Anticipated outcomes of the COVID-19 pandemic based on a rapid review of select "Big Events", as reported in Zolopa et al 2021; Table S1. Changes in income sources; Table S2. Access to drug/alcohol treatment and harm reduction during the health emergency.


Glioblastoma (GBM) is the most common and fatal primary malignant brain neoplasm in adults . The curradiomics” has the potential to change the ways in which advanced MR imaging techniques can be utilized more efficiently  imaging sequences provide valuable information about the anatomic details and blood-brain-barrier (BBB) integrity, they lack specificity in characterizing gliomas as these neoplasms are highly heterogeneous both in spatial and temporal dimensions. Continuous developments in metabolic and physiologic MR imaging techniques have provided new insights into understanding underlying tumor biology and tumor microenvironment –9. Takeniciently . This Re1 values of tissue water within the EES, thereby increasing MR signal results in an underestimation of cerebral blood volume (CBV). Conversely, T2*-effects caused by changes in susceptibility differences between EES and intravascular compartments reduce the MR signal, which does not recover to baseline during the DSC scan. This effect causes an overestimation of CBV. When the contrast agent extravasation is especially fast , CBV can be calculated as a negative estimate because the signal increase caused by T1 effects is greater than the signal reduction due to T2* effects. To address this problem of contrast leakage in gliomas, Arzanforoosh et al. investigated the effect of two known leakage correction algorithms on CBV measurements. The leakage correction algorithms were based on unidirectional contrast agent transport from the intravascular to EES and bidirectional contrast agent transport between these two compartments. The investigators reported that in enhancing gliomas , applying either of these two leakage correction methods decreased CBV measurements.The leakage of the contrast agent into the extravascular extracellular space (EES) during the dynamic susceptibility contrast (DSC)-perfusion MRI affects the signals produced in two competing ways. Contrast agent shortens TYang et al. identified endothelial cell-enriched genes from transcriptome data from the GBM patients. The investigators demonstrated that contrast enhancement was associated with distinct vascular molecular imprints which is characterized by up-regulation of proinflammatory genes and de-regulation of BBB-related genes in endothelial cells. Moreover, high contrast enhancement was associated with poor patient prognosis and survival outcomes. Furthermore, enhancing volume/complete tumor volume ratio was significantly higher in the mesenchymal subtype of GBMs.While exploring the potential associations between molecular features and patterns of contrast enhancement in GBMs, Huang et al. have suggested that neuroplasticity in patients with insular glioma might play a crucial role in preserving the neurological functions and subsequently improving the post-resection prognosis. The authors correlated gene expression profiles of isocitrate dehydrogenase (IDH), telomerase reverse transcriptase (TERT), and 1p19q codeletions with MRI volumetric data. The authors observed that IDH mutation status was the only genotype that was found to be associated with significant structural compensation in patients with insular glioma. These authors suggested that such findings may help in predicting neurocognitive and functional outcomes in patients with insular glioma undergoing surgical resection.Safai et al. developed a machine learning-based diagnostic model by using quantitative radiomic signatures from multi-model MRI data for distinguishing adult STEE from HGG. The investigators reported that texture-based radiomic features from T2-FLAIR images were vital in discriminating STEE from GBM. On the other hand, first-order features from T2-weighted images and apparent diffusion coefficient (ADC) maps were consistently ranked higher in differentiating multiple tumor groups.Adult supratentorial extra ventricular ependymoma (STEE) are rare neoplasms often misdiagnosed as high-grade gliomas (HGG) due to their similar characteristics on conventional neuroimaging. 18F-FDG)-positron emission tomography (PET) and other inherent shortcomings associated with this technique, Mangalore et al. explored whether high “b” value diffusion-weighted imaging (DWI) and 18FDG-PET can provide similar or complementary information in detecting malignant brain lesions. The investigators obtained comparable sensitivity and specificity for DWI and 18FDG-PET derived parameters and concluded that DWI could act as a surrogate for 18FDG-PET in the diagnosis of brain tumors.Against the backdrop of growing concern over patients' radiation exposure from undergoing 2-deoxy-2-[fluorine-18]fluoro-D-glucose . This integrated model provided significantly better diagnostic performance than the utilization of any single imaging parameter alone.Despite the clinical importance, the accurate distinction between GBMs and solitary metastasis often remains challenging as these entities exhibit similar features on conventional neuroimaging. To address this issue, Wong et al. developed a mathematical model by incorporating multiple clinical features and imaging factors  in predicting malignant transformation of low-grade gliomas. This model had an accuracy of 84% from the training group and 85% from the validation group.Using multivariate logistic regression analyses, Cui et al. investigated the prognostic significance of metabolic alterations from the postoperative peritumoral edematous zone (PEZ) in GBMs. Authors proposed that an elevated choline/N-acetyl aspartate ratio in PEZ can be considered as an independent risk factor for predicting early tumor recurrence. Moreover, this metabolic abnormality was also associated with poor prognosis and adverse clinical outcomes in patients with GBM.In a seminal study, Lamichhane et al. classified GBM patients into short-term and long-term survival groups with high sensitivity and specificity (precision prognostics).By leveraging the utility of unique brain functional connectivity information obtained from resting-state functional MRI combined with machine learning algorithms, Booth et al.).Determining the utility of interval imaging  in brain tumor management remains crucial in neuro-oncology. An expert panel comprising of professionals from data science, health economics, trial management of adult brain tumors, and patient representatives extensively reviewed the current evidence on the use of interval imaging to monitor brain tumors, and summarized their findings in a review article. The investigators concluded that evidence for the value of regular interval imaging is currently lacking. At the same time, the authors indicated that ongoing collaborative efforts might provide some evidence to optimize monitoring imaging biomarkers for the standard of care brain tumor management (Kumar et al. comprehensively showcased the clinical potentials of emerging metabolic imaging techniques such as 3D-echoplanar spectroscopic imaging, 2D-correlation spectroscopy, and chemical exchange saturation transfer imaging in several neuro-oncologic applications. The authors also provided a detailed head-to-head comparison of these three metabolic techniques.A review article by Gonçalves et al. provided an overview on the potential utilities of advanced MR imaging techniques for studying pediatric GBMs.In another review article, Radiomics” is a relatively young and evolving field, and has a tremendous potential to provide meaningful biological understandings of imaging features for further improvement in the clinical outcomes and quality of life of these patients. However, the widespread translation of advanced imaging and radiomics methods into the routine clinical workflow has been slow due to some technical challenges. We believe that standardization as well as harmonization of data acquisition and post-processing procedures will strengthen the clinical applications and advance progress toward developing and validating new imaging biomarkers in the field of neuro-oncology.Altogether, the studies published in this special issue have highlighted the importance of using advanced MR imaging and PET imaging techniques in redefining and reshaping our understanding of GBMs. Collectively, these techniques provide crucial information about the tumor microstructure, microvasculature, and metabolism, thus offering opportunities for optimizing clinical care of glioma patients. “All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. 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In developed countries, aortic coarctation (AC) is generally diagnosed by fetal echocardiography during the third trimester of pregnancy, or during the neonatal period based on the absence of femoral pulses or the presence of a left supraclavicular systolic murmur. However, AC may be diagnosed late, such as in adult migrants arriving from developing countries without documented medical history although they may require healthcare support during their stay. We report three cases of the incidental diagnosis of thoracic aortic malformations in adults  referred for the management of uncontrolled high blood pressure, with major cerebrovascular events for the two oldest. Doppler ultrasound imaging indicated for suspected renal artery stenosis and atheroma lesions revealed abnormal lower-body and normal upper-body arterial blood flow velocity waveforms constitutive of a pathognomonic hemodynamic pattern of AC, a diagnostic which was in all three cases confirmed by multidetector computed tomography-angiography. None of these patients had undergone complete cardiovascular examination, particularly with effective peripheral pulse palpation, during the period preceding the occurrence of major cardiovascular events or at any other time after birth. Our observation suggests that a simple medical examination could have prevented diagnostic wandering and, possibly, the occurrence of severe cerebrovascular complications in two of these three patients. A “tardus-parvus” pattern is a modification in the spectral analysis of the blood flow velocity waveform that combines three criteria: an enhanced systolic rise-time (by >0.07 s), a decrease in peak systolic velocity, and a low resistive index. The internal thoracic arteries, side branches of the subclavian arteries, and the epigastric arteries were dilated and anastomosed at epigastria. Pulsed Doppler ultrasound showed high levels of anterograde blood flow in the internal thoracic arteries and high levels of retrograde blood flow in the epigastric arteries supplying the femoral arteries . The patient presented weakness of the lower limbs, NYHA II exertional dyspnea, and atypical chest pain. Doppler ultrasound imaging of the carotid and subclavian arteries displayed normal blood flow velocity waveforms. The walls of the abdominal aorta and renal, digestive, and lower-limb arteries were normal, whereas the abdominal infra renal aorta was thin, with an external diameter of 13 mm. Pulsed Doppler ultrasound revealed “ies Fig. . The ankies Fig. . The pat−1) treated with dual therapy (20 mg lisinopril and 12.5 mg hydrochlorothiazide), heterozygosity for the sickle cell trait, and the use of nasal vasoconstrictors one month before the stroke. Doppler ultrasound imaging of carotid, subclavian, internal thoracic, abdominal aortic, renal and femoral arteries revealed similar hemodynamic patterns as in patient 1. A diagnosis of AC was, therefore, suspected and confirmed by multidetector computed tomography angiography. Unfortunately, the patient suffered a lethal hemorrhagic transformation of his ischemic stroke.Patient 2 was 38-year-old with uncontrolled hypertension hospitalized for an inaugural ischemic stroke. The neurology department subsequently referred this patient for Doppler ultrasound imaging to check for renal artery stenosis and for carotid atheroma. The patient’s medical history included hypertension with mild hypokalemia  but successful end-to-end aortic anastomosis. This surgical procedure restored normal blood flow velocity waveforms in all the abdominal and lower-limb arteries, but arterial hypertension requiring pharmacological treatment  persisted. The long time interval between diagnosis and surgical treatment was due to the administrative difficulties often faced by migrant workers seeking medical care in France.tardus-parvus” pattern of all blood flow velocity waveforms for all abdominal visceral and lower-limb arteries associated with normal blood flow velocity waveforms for the cephalic and upper-limb arteries. The “tardus-parvus” pattern due to the presence of an upstream tight arterial stenosis consists of enhanced systolic rise-time (by >0.07 s), a decrease in peak systolic velocity, and low resistive indices related to downstream arteriolar vasodilation as an adaptation to the decrease in hemodynamic pressures. The existence of a “tardus-parvus” pattern in both renal arteries was previously reported to be due to the presence of an upstream AC in two boys (11- and 15 years of age) [NOTCH1 gene, encoding a protein involved in cardiac development and vasculogenesis, may also be involved [The hemodynamic presentation common to all three patients on ultrasound examination was the presence of a “ of age)  and in o of age) , but suc of age) . Its cauinvolved . Less the by >0.0 s, a decAortic coarctation correction may not normalize blood pressure as the mechanisms driving hypertension are partially independent. Endothelial dysfunction is systematic and may underlie the persistence of hypertension even after surgical or endovascular treatment . FurtherAll three patients were of African origin, native to Africa. In West and Central Africa, only one in two women gives birth in healthcare facilities. Effective clinical examinations at birth are therefore lacking for most infants. Pregnant women also have limited access to antenatal gynecological consultations. We would recommend that individuals originating from developing countries that have a history of walking difficulties from childhood and present with arterial hypertension in adulthood should systematically undergo examination for unidentified aortic malformations. The first step in this process should be the verification of femoral pulses. If undetectable, Doppler ultrasound examinations should be performed and followed by multidetector computed tomography angiography or magnetic resonance-angiography. In addition, we would recommend that such patients undergo specific assessments for congenital heart diseases, such as tetralogy of Fallot , pulmona