Large-scale real-life implementation of technology-enabled care to maximize hospitals' medical surge preparedness during future infectious disease outbreaks and winter seasons: a viewpoint.

Hospitals can be overburdened with large numbers of patients with severe infectious conditions during infectious disease outbreaks. Such outbreaks or epidemics put tremendous pressure on the admission capacity of care facilities in the concerned region, negatively affecting the elective program within these facilities. Such situations have been observed during the recent waves of the coronavirus disease pandemic. Owing to the imminent threat of a "tripledemic" by new variants of the coronavirus disease (such as the new Omicron XBB.1.16 strain), influenza, and respiratory syncytial virus during future winter seasons, healthcare agencies should take decisive steps to safeguard hospitals' surge capacity while continuing to provide optimal and safe care to a potentially large number of patients in their trusted home environment. Preparedness of health systems for infectious diseases will require dynamic interaction between a continuous assessment of region-wide available hospital capacity and programs for intensive home treatment of patients who can spread the disease. In this viewpoint, we describe an innovative, dynamic coupling system between hospital surge capacity and cascading activation of a nationwide system for remote patient monitoring. This approach was developed using the multi-criteria decision analysis methodology, considering previously published real-life experiences on remote patient monitoring.

Arteriovenous malformation Map2k1 mutation affects vasculogenesis.

Somatic activating MAP2K1 mutations in endothelial cells (ECs) cause extracranial arteriovenous malformation (AVM). We previously reported the generation of a mouse line allowing inducible expression of constitutively active MAP2K1 (p.K57N) from the Rosa locus (R26GT-Map2k1-GFP/+) and showed, using Tg-Cdh5CreER, that EC expression of mutant MAP2K1 is sufficient for the development of vascular malformations in the brain, ear, and intestines. To gain further insight into the mechanism by which mutant MAP2K1 drives AVM development, we induced MAP2K1 (p.K57N) expression in ECs of postnatal-day-1 pups (P1) and investigated the changes in gene expression in P9 brain ECs by RNA-seq. We found that over-expression of MAP2K1 altered the transcript abundance of > 1600 genes. Several genes had > 20-fold changes between MAP2K1 expressing and wild-type ECs; the highest were Col15a1 (39-fold) and Itgb3 (24-fold). Increased expression of COL15A1 in R26GT-Map2k1-GFP/+; Tg-Cdh5CreER+/- brain ECs was validated by immunostaining. Ontology showed that differentially expressed genes were involved in processes important for vasculogenesis (e.g., cell migration, adhesion, extracellular matrix organization, tube formation, angiogenesis). Understanding how these genes and pathways contribute to AVM formation will help identify targets for therapeutic intervention.

Endothelial cell expression of mutant Map2k1 causes vascular malformations in mice.

Extracranial arteriovenous malformation (AVM) is a congenital vascular anomaly causing disfigurement, bleeding, ulceration, and pain. Most lesions are associated with somatic MAP2K1 activating mutations in endothelial cells (ECs). The purpose of this study was to determine if EC expression of mutant activated MAP2K1 is sufficient to produce vascular malformations in mice. We generated mice with a ROSA26 allele containing a lox-stop-lox gene trap (GT), Map2k1 cDNA with an activating p.K57N missense mutation, an internal ribosomal entry site, and green fluorescent protein cDNA (R26GT-Map2k1-GFP). We expressed mutant MAP2K1 and GFP in ECs of fetal and newborn mice using Tg-Cdh5Cre or Tg-Cdh5CreER alleles. Tg-Cdh5Cre+/-;R26GT-Map2k1-GFP/+ animals that express mutant MAP2K1 in ECs in utero developed diffuse vascular abnormalities and died by embryonic (E) day 16.5. Tg-Cdh5CreER+/-;R26GT-Map2k1-GFP/+ animals in which mutant MAP2K1 expression was induced in ECs by tamoxifen at postnatal (P) day 1 developed vascular malformations in the brain, ear, and intestines by P23. The lesions consisted of abnormal networks of blood vessels containing recombined and non-recombined ECs. In conclusion, expression of MAP2K1 p.K57N is sufficient to cause vascular malformations in mice. This model can be used to study the malformation process and for pre-clinical pharmacologic studies.

Laboratory analysis of two Delta SARS-CoV-2 variant outbreaks in the Port of Antwerp.

INTRODUCTION: The B.1.617.2 SARS-CoV-2 or Delta variant, first detected in India, has shown a rapid global spread due to its high transmissibility and now represents more than 99% of the currently circulating variants in Europe. METHODS AND RESULT: In May 2021, two ships that had recently arrived in the Port of Antwerp reported crew members with COVID-like symptoms. SARS-CoV-2 RNA was detected in nasopharyngeal swabs in 30 out of 45 skippers and the B.1.617.2 variant was identified via whole genome sequencing. Crew members were isolated or quarantined and repeatedly tested to assess the evolution of their SARS-CoV-2 viral load based on the cycle threshold (CT) values of the PCR reaction. Viral cultures were also taken at day 7 to detect viable virus and were compared with the subjects CT value at that moment. The shipper's clinical condition was closely observed using a digital home monitoring tool. Eleven crew members (37%) required hospitalization, with CT values of SARS-CoV-2 RNA being a good predictive factor for the hospitalization need. Furthermore, a clear correlation between CT values and positive viral culture was observed, hinting infectiousness even longer than 10 days after the intitial positive PCR test. CONCLUSION: Our study of 2 Delta variant clusters shows that the initial CT value is a good predictor for hospitalization need and suggests that patients infected with this variant may remain infectious for a longer time period.

Parkes Weber syndrome with lymphedema caused by a somatic KRAS variant.

Parkes Weber syndrome is a vascular malformation overgrowth condition typically involving the legs. Its main features are diffuse arteriovenous fistulas and enlargement of the limb. The condition has been associated with pathogenic germline variants in RASA1 and EPHB4 We report two individuals with Parkes Weber syndrome of the leg and primary lymphedema containing a somatic KRAS variant (NM_004985.5:c.35G > A; p.Gly12Asp). KRAS variants, which cause somatic intracranial and extracranial arteriovenous malformations, also result in Parkes Weber syndrome with lymphatic malformations.

Bockenheimer disease is associated with a TEK variant.

Bockenheimer disease is a venous malformation involving all tissues of an extremity. Patients have significant morbidity, and treatment is palliative. The purpose of this study was to identify the cause of Bockenheimer disease to develop pharmacotherapy for the condition. Paraffin-embedded tissue from nine individuals with Bockenheimer disease obtained during a clinically indicated operation underwent DNA extraction. Droplet digital polymerase chain reaction (ddPCR) was used to screen for variants most commonly associated with sporadic venous malformations (TEK [NM_000459.5:c.2740C > T; p.Leu914Phe], PIK3CA [NM_006218.4:c.1624G > A; p.Glu542Lys and NM_006218.4:c.3140A > G; p.His1047Arg]). ddPCR detected a TEK L914F variant in all nine patients (variant allele fraction 2%-13%). PIK3CA E542K and H1047R variants were not identified in the specimens. Sanger sequencing and restriction enzyme digestion confirmed variants identified by ddPCR. A pathogenic variant in the endothelial cell tyrosine kinase receptor TEK is associated with Bockenheimer disease. Pharmacotherapy targeting the TEK signaling pathway might benefit patients with the condition.

EPHB4 mutation causes adult and adolescent-onset primary lymphedema.

Primary lymphedema results from the anomalous development of the lymphatic system and typically presents during infancy, childhood, or adolescence. Adult-onset primary lymphedema is rare and mutations associated with this condition have not been identified. The purpose of this investigation was to search for variants that cause adult-onset primary lymphedema. We discovered an autosomal dominant EPHB4 mutation in a patient who developed unilateral leg lymphedema at age 39 years; the same mutation affected his son who presented with the disease at 14 years of age.

Lipoblastoma phenotype contains a somatic PIK3CA mutation.

Lipoblastoma typically occurs in childhood and is associated with rearrangements of the PLAG1 gene. We present a patient with an isolated mass thought to be a lipoblastoma clinically, radiographically, and histologically. The lesion was diagnosed as a PIK3CA-adipose lesion after the tissue was negative for PLAG1 rearrangement and contained a somatic PIK3CA mutation (H1047R). Although PIK3CA variants are associated with PROS (PIK3CA-related overgrowth spectrum), this report illustrates a non-syndromic, lipoblastoma phenotype caused by a PIK3CA mutation.

Arteriovenous malformation phenotype resembling congenital hemangioma contains KRAS mutations.

Extracranial arteriovenous malformation (AVM) is most commonly caused by a somatic mutation in MAP2K1. We report two patients with vascular anomalies that had an unclear clinical diagnosis most consistent with either an AVM or congenital hemangioma. Lesions were cutaneous, reddish-purple with telangiectasias, present at birth, and had defined borders. Histopathology indicated AVM and both lesions contained somatic KRAS mutations. A rare AVM phenotype exists that shares clinical features with congenital hemangioma.

Endothelial MAP2K1 mutations in arteriovenous malformation activate the RAS/MAPK pathway.

Arteriovenous malformation (AVM) is a locally destructive congenital vascular anomaly caused by somatic mutations in MAP2K1. The mutation is isolated to endothelial cells (ECs). The purpose of this study was to determine the effects of mutant MAP2K1 on EC signaling and vascular network formation. Pathway effects were studied using both mutant MAP2K1 (K57N) human AVM tissue and human umbilical vein endothelial cells (HUVECs) engineered to overexpress the MAP2K1 (K57N) mutation. Western blot was used to determine cell signaling along the RAS/MAPK pathway. Geltrex tube formation assays were performed to assess EC vascular network formation. Cells were treated with a MAP2K1 inhibitor (Trametinib) to determine its effect on signaling and vascular tube formation. Human mutant MAP2K1-AVM ECs had similar baseline MEK1 and ERK1/2 expression with controls; however, mutant MAP2K1-AVM ECs produced significantly more phosphorylated ERK1/2 than wild-type ECs. Mutant MAP2K1 HUVECs demonstrated significantly more phosphorylated ERK1/2 than control HUVECs. Trametinib reduced the phosphorylation of ERK1/2 in mutant cells and prevented the ability of ECs to form vascular networks. AVM MAP2K1 mutations activate RAS/MAPK signaling in ECs. ERK activation and vascular network formation are reduced with Trametinib. Pharmacotherapy using MAP2K1 inhibitors may prevent the formation or progression of AVMs.

Arteriovenous Malformation MAP2K1 Mutation Causes Local Cartilage Overgrowth by a Cell-Non Autonomous Mechanism.

Extracranial arteriovenous malformation (AVM) is most commonly caused by MAP2K1 mutations in the endothelial cell. The purpose of this study was to determine if local tissue overgrowth associated with AVM is caused by direct or indirect effects of the MAP2K1 mutation (i.e., cell-autonomous or cell-non autonomous). Because cartilage does not have blood vessels, we studied ear AVMs to determine if overgrown cartilage contained AVM-causing mutations. Cartilage was separated from its surrounding tissue and isolated by laser capture microdissection. Droplet digital PCR (ddPCR) was used to identify MAP2K1 mutations. MAP2K1 (p.K57N) variants were present in the tissue adjacent to the cartilage [mutant allele frequency (MAF) 6-8%], and were enriched in endothelial cells (MAF 51%) compared to non-endothelial cells (MAF 0%). MAP2K1 mutations were not identified in the overgrown cartilage, and thus local cartilage overgrowth likely results from the effects of adjacent mutant blood vessels (i.e., cell-non autonomous).

Author Correction: Historical contingency shapes adaptive radiation in Antarctic fishes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Diffuse capillary malformation with overgrowth contains somatic PIK3CA variants.

Diffuse capillary malformation with overgrowth (DCMO) is a clinical diagnosis describing patients with multiple, extensive capillary malformations (CMs) associated with overgrowth and foot anomalies. The purpose of the study was to identify somatic variants in DCMO. Skin containing CM and overgrown subcutaneous adipose tissue was collected from patients with DCMO. Exons from 447 cancer-related genes were sequenced using OncoPanel. Variant-specific droplet digital PCR (ddPCR) independently confirmed the variants and determined variant allele frequencies (VAF). One subject contained a somatic PIK3CA p.G106V variant. A second patient had a PIK3CA p.D350G variant. VAF was 27% to 29% in skin and 16% to 28% in subcutaneous adipose. Variants were enriched in endothelial cells (VAF 50%-51%) compared to nonendothelial cells (1%-8%). DCMO is associated with somatic PIK3CA variants and should be considered on the PIK3CA-related overgrowth spectrum (PROS). Variants are present in both skin and subcutaneous adipose and are enriched in endothelial cells.

Arteriovenous malformation associated with a HRAS mutation.

The majority of extracranial arteriovenous malformations (AVMs) are caused by somatic mutations in MAP2K1. We report a somatic HRAS mutation in a patient who has a facial AVM associated with subcutaneous adipose overgrowth. We performed whole exome sequencing on DNA from the affected tissue and found a HRAS mutation (p.Thr58_Ala59delinsValLeuAspVal). Mutant allelic frequency was 5% in whole tissue and 31% in isolated endothelial cells (ECs); the mutation was not present in blood DNA or non-ECs. Somatic mutations in HRAS can cause AVM.

Intramuscular fast-flow vascular anomaly contains somatic MAP2K1 and KRAS mutations.

BACKGROUND: The term "intramuscular hemangioma capillary type" (IHCT) refers to a fast-flow vascular lesion that is classified as a tumor, although its phenotype overlaps with arteriovenous malformation (AVM). The purpose of this study was to identify somatic mutations in IHCT. METHODS: Affected tissue specimens were obtained during a clinically indicated procedure. The diagnosis of IHCT was based on history, physical examination, imaging and histopathology. Because somatic mutations in cancer-associated genes can cause vascular malformations, we sequenced exons from 446 cancer-related genes in DNA from 7 IHCT specimens. We then performed mutation-specific droplet digital PCR (ddPCR) to independently test for the presence of a somatic mutation found by sequencing and to screen one additional IHCT sample. RESULTS: We detected somatic mutations in 6 of 8 IHCT specimens. Four specimens had a mutation in MAP2K1 (p.Q58_E62del, p.P105_I107delinsL, p.Q56P) and 2 specimens had mutations in KRAS (p.K5E and p.G12D, p.G12D and p.Q22R). Mutant allele frequencies detected by sequencing and confirmed by ddPCR ranged from 2 to 15%. CONCLUSIONS: IHCT lesions are phenotypically similar to AVMs and contain the same somatic MAP2K1 or KRAS mutations, suggesting that IHCT is on the AVM spectrum. We propose calling this lesion "intramuscular fast-flow vascular anomaly."

Historical contingency shapes adaptive radiation in Antarctic fishes.

Adaptive radiation illustrates links between ecological opportunity, natural selection and the generation of biodiversity. Central to adaptive radiation is the association between a diversifying lineage and the evolution of phenotypic variation that facilitates the use of new environments or resources. However, is not clear whether adaptive evolution or historical contingency is more important for the origin of key phenotypic traits in adaptive radiation. Here we use targeted sequencing of >250,000 loci across 46 species to examine hypotheses concerning the origin and diversification of key traits in the adaptive radiation of Antarctic notothenioid fishes. Contrary to expectations of adaptive evolution, we show that notothenioids experienced a punctuated burst of genomic diversification and evolved key skeletal modifications before the onset of polar conditions in the Southern Ocean. We show that diversifying selection in pathways associated with human skeletal dysplasias facilitates ecologically important variation in buoyancy among Antarctic notothenioid species, and demonstrate the sufficiency of altered trip11, col1a2 and col1a1a function in zebrafish (Danio rerio) to phenocopy skeletal reduction in Antarctic notothenioids. Rather than adaptation being driven by the cooling of the Antarctic, our results highlight the role of historical contingency in shaping the adaptive radiation of notothenioids. Understanding the historical and environmental context for the origin of key traits in adaptive radiations extends beyond reconstructing events that result in evolutionary innovation, as it also provides a context in forecasting the effects of climate change on the stability and evolvability of natural populations.

Somatic mutations in intracranial arteriovenous malformations.

BACKGROUND: Intracranial arteriovenous malformation (AVM) is a common cause of primary intracerebral hemorrhage in young adults. Lesions typically are sporadic and contain somatic mutations in KRAS or BRAF. The purpose of this study was to identify somatic mutations in a cohort of participants with brain AVM and to determine if any genotype-phenotype associations exist. METHODS: Human brain AVM specimens (n = 16) were collected during a clinically-indicated procedure and subjected to multiplex targeted sequencing using molecular inversion probe (MIP-seq) for mutations in KRAS, BRAF, HRAS, NRAS, and MAP2K1. Endothelial cells (ECs) were separated from non-ECs by immune-affinity purification. Droplet digital PCR (ddPCR) was used to confirm mutations and to screen for mutations that may have been missed by MIP-seq. Patient and AVM characteristics were recorded. RESULTS: We detected somatic mutations in 10 of 16 specimens (63%). Eight had KRAS mutations [G12D (n = 5), G12V (n = 3)] and two had BRAF mutations [V600E (n = 1), Q636X (n = 1)]. We found no difference in age, sex, presenting symptom, AVM location, or AVM size between patients with a confirmed mutation and those without. Nor did we observe differences in these features between patients with KRAS or BRAF mutations. However, two patients with BRAF mutations presented at an older age than other study participants. CONCLUSIONS: Somatic mutations in KRAS and, less commonly in BRAF, are found in many but not all intracranial AVM samples. Currently, there are no obvious genotype-phenotype correlations that can be used to predict whether a somatic mutation will be detected and, if so, which gene will be mutated.

The skeletal phenotype of achondrogenesis type 1A is caused exclusively by cartilage defects.

Inactivating mutations in the ubiquitously expressed membrane trafficking component GMAP-210 (encoded by Trip11) cause achondrogenesis type 1A (ACG1A). ACG1A is surprisingly tissue specific, mainly affecting cartilage development. Bone development is also abnormal, but as chondrogenesis and osteogenesis are closely coupled, this could be a secondary consequence of the cartilage defect. A possible explanation for the tissue specificity of ACG1A is that cartilage and bone are highly secretory tissues with a high use of the membrane trafficking machinery. The perinatal lethality of ACG1A prevents investigating this hypothesis. We therefore generated mice with conditional Trip11 knockout alleles and inactivated Trip11 in chondrocytes, osteoblasts, osteoclasts and pancreas acinar cells, all highly secretory cell types. We discovered that the ACG1A skeletal phenotype is solely due to absence of GMAP-210 in chondrocytes. Mice lacking GMAP-210 in osteoblasts, osteoclasts and acinar cells were normal. When we inactivated Trip11 in primary chondrocyte cultures, GMAP-210 deficiency affected trafficking of a subset of chondrocyte-expressed proteins rather than globally impairing membrane trafficking. Thus, GMAP-210 is essential for trafficking specific cargoes in chondrocytes but is dispensable in other highly secretory cells.

Lubricin restoration in a mouse model of congenital deficiency.

OBJECTIVE: Congenital deficiency of the principal boundary lubricant in cartilage (i.e., lubricin, encoded by the gene PRG4) increases joint friction and causes progressive joint failure. This study was undertaken to determine whether restoring lubricin expression in a mouse model would prevent, delay, or reverse the disease process caused by congenital deficiency. METHODS: Using genetically engineered lubricin-deficient mice, we restored gene function before conception or at ages 3 weeks, 2 months, or 6 months after birth. The effect of restoring gene function (i.e., expression of lubricin) on the tibiofemoral patellar joints of mice was evaluated histologically and by ex vivo biomechanical testing. RESULTS: Restoring gene function in mice prior to conception prevented joint disease. In 3-week-old mice, restoring gene function improved, but did not normalize, histologic features of the articular cartilage and whole-joint friction. In addition, cyclic loading of the joints produced fewer activated caspase 3-containing chondrocytes when lubricin expression was restored, as compared to that in littermate mice whose gene function was not restored (nonrestored controls). Restoration of lubricin expression in 2-month-old or 6-month-old mice had no beneficial effect on histopathologic cartilage damage, extent of whole-joint friction, or activation of caspase 3 when compared to nonrestored controls. CONCLUSION: When boundary lubrication is congenitally deficient and cartilage becomes damaged, the window of opportunity for restoring lubrication and slowing disease progression is limited.