Evolutionary origin of Hoxc13-dependent skin appendages in amphibians

Cornified skin appendages, such as hair and nails, are major evolutionary innovations of terrestrial vertebrates. Human hair and nails consist largely of special intermediate filament proteins, known as hair keratins, which are expressed under the control of the transcription factor Hoxc13. Here, we show that the cornified claws of Xenopus frogs contain homologs of hair keratins and the genes encoding these keratins are flanked by promoters in which binding sites of Hoxc13 are conserved. Furthermore, these keratins and Hoxc13 are co-expressed in the claw-forming epithelium of frog toe tips. Upon deletion of hoxc13, the expression of hair keratin homologs is abolished and the development of cornified claws is abrogated in X. tropicalis. These results indicate that Hoxc13-dependent expression of hair keratin homologs evolved already in stem tetrapods, presumably as a mechanism for protecting toe tips, and that this ancestral genetic program was coopted to the growth of hair in mammals.

Mutations in the histone methyltransferase Ezh2 drive context-dependent leukemia in Xenopus tropicalis

CRISPR-mediated simultaneous targeting of candidate tumor suppressor genes in Xenopus tropicalis allows fast functional assessment of co-driver genes for various solid tumors. Genotyping of tumors that emerge in the mosaic mutant animals rapidly exposes the gene mutations under positive selection for tumor establishment. However, applying this simple approach to the blood lineage has not been attempted. Multiple hematologic malignancies have mutations in EZH2, encoding the catalytic subunit of the Polycomb Repressive Complex 2. Interestingly, EZH2 can act as an oncogene or a tumor suppressor, depending on cellular context and disease stage. We show here that mosaic CRISPR/Cas9 mediated ezh2 disruption in the blood lineage resulted in early and penetrant acute myeloid leukemia (AML) induction. While animals were co-targeted with an sgRNA that induces notch1 gain-of-function mutations, sequencing of leukemias revealed positive selection towards biallelic ezh2 mutations regardless of notch1 mutational status. Co-targeting dnm2, recurrently mutated in T/ETP-ALL, induced a switch from myeloid towards acute T-cell leukemia. Both myeloid and T-cell leukemias engrafted in immunocompromised hosts. These data underline the potential of Xenopus tropicalis for modeling human leukemia, where mosaic gene disruption, combined with deep amplicon sequencing of the targeted genomic regions, can rapidly and efficiently expose co-operating driver gene mutations.

Impact on grafted kidney function of rocuronium-sugammadex vs cisatracurium-neostigmine strategy for neuromuscular block management. An Italian single-center, 2014-2017 retrospective cohort case-control study

Background

The impact of sugammadex in patients with end-stage renal disease undergoing kidney transplantation is still far from being defined. The aim of the study is to compare sugammadex to neostigmine for reversal of rocuronium- and cisatracurium-induced neuromuscular block (NMB), respectively, in patients undergoing kidney transplantation.

Methods

A single-center, 2014-2017 retrospective cohort case-control study was performed. A total of 350 patients undergoing kidney transplantation, equally divided between a sugammadex group (175 patients) and a neostigmine group (175 patients), were considered. Postoperative kidney function, evaluated by monitoring of serum creatinine and urea and estimated glomerular filtration rate (eGFR), was the endpoint. Other endpoints were anesthetic and surgical times, post-anesthesia care unit length of stay, postoperative intensive care unit admission, and recurrent NMB or complications.

Results

No significant differences in patient or, with the exception of drugs involved in NMB management, anesthetic, and surgical characteristics, were observed between the two groups. Serum creatinine (median [interquartile range]: 596.0 [478.0-749.0] vs 639.0 [527.7-870.0] μmol/L, p = 0.0128) and serum urea (14.9 [10.8-21.6] vs 17.1 [13.1-22.0] mmol/L, p = 0.0486) were lower, while eGFR (8.0 [6.0-11.0] vs 8.0 [6.0-10.0], p = 0.0473) was higher in the sugammadex group than in the neostigmine group after surgery. The sugammadex group showed significantly lower incidence of postoperative severe hypoxemia (0.6% vs 6.3%, p = 0.006), shorter PACU stay (70 [60-90] min vs 90 [60-105] min, p < 0.001), and reduced ICU admissions (0.6% vs 8.0%, p = 0.001).

Conclusions

Compared to cisatracurium-neostigmine, the rocuronium-sugammadex strategy for reversal of NMB showed a better recovery profile in patients undergoing kidney transplantation.

Maximizing CRISPR/Cas9 phenotype penetrance applying predictive modeling of editing outcomes in Xenopus and zebrafish embryos

CRISPR/Cas9 genome editing has revolutionized functional genomics in vertebrates. However, CRISPR/Cas9 edited F0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (DSB) repair. Even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. Recently, studies in cell culture systems have shown that the nature of CRISPR/Cas9-mediated mutations can be dependent on local sequence context and can be predicted by computational methods. Here, we demonstrate that similar approaches can be used to forecast CRISPR/Cas9 gene editing outcomes in Xenopus tropicalis, Xenopus laevis, and zebrafish. We show that a publicly available neural network previously trained in mouse embryonic stem cell cultures (InDelphi-mESC) is able to accurately predict CRISPR/Cas9 gene editing outcomes in early vertebrate embryos. Our observations can have direct implications for experiment design, allowing the selection of guide RNAs with predicted repair outcome signatures enriched towards frameshift mutations, allowing maximization of CRISPR/Cas9 phenotype penetrance in the F0 generation.

RBL1 (p107) functions as tumor suppressor in glioblastoma and small-cell pancreatic neuroendocrine carcinoma in Xenopus tropicalis

Alterations of the retinoblastoma and/or the p53 signaling network are associated with specific cancers such as high-grade astrocytoma/glioblastoma, small-cell lung cancer (SCLC), choroid plexus tumors, and small-cell pancreatic neuroendocrine carcinoma (SC-PaNEC). However, the intricate functional redundancy between RB1 and the related pocket proteins RBL1/p107 and RBL2/p130 in suppressing tumorigenesis remains poorly understood. Here we performed lineage-restricted parallel inactivation of rb1 and rbl1 by multiplex CRISPR/Cas9 genome editing in the true diploid Xenopus tropicalis to gain insight into this in vivo redundancy. We show that while rb1 inactivation is sufficient to induce choroid plexus papilloma, combined rb1 and rbl1 inactivation is required and sufficient to drive SC-PaNEC, retinoblastoma and astrocytoma. Further, using a novel Li-Fraumeni syndrome-mimicking tp53 mutant X. tropicalis line, we demonstrate increased malignancy of rb1/rbl1-mutant glioma towards glioblastoma upon concomitant inactivation of tp53. Interestingly, although clinical SC-PaNEC samples are characterized by abnormal p53 expression or localization, in the current experimental models, the tp53 status had little effect on the establishment and growth of SC-PaNEC, but may rather be essential for maintaining chromosomal stability. SCLC was only rarely observed in our experimental setup, indicating requirement of additional or alternative oncogenic insults. In conclusion, we used CRISPR/Cas9 to delineate the tumor suppressor properties of Rbl1, generating new insights in the functional redundancy within the retinoblastoma protein family in suppressing neuroendocrine pancreatic cancer and glioma/glioblastoma.

Perioperative care of the obese patient

Background

Obesity has become an increasing problem worldwide during the past few decades. Hence, surgeons and anaesthetists will care for an increasing number of obese patients in the foreseeable future, and should be prepared to provide optimal management for these individuals. This review provides an update of recent evidence regarding perioperative strategies for obese patients.

Methods

A search for papers on the perioperative care of obese patients (English language only) was performed in July 2019 using the PubMed, Scopus, Web of Science and Cochrane Library electronic databases. The review focused on the results of RCTs, although observational studies, meta-analyses, reviews, guidelines and other reports discussing the perioperative care of obese patients were also considered. When data from obese patients were not available, relevant data from non-obese populations were used.

Results and conclusion

Obese patients require comprehensive preoperative evaluation. Experienced medical teams, appropriate equipment and monitoring, careful anaesthetic management, and an adequate perioperative ventilation strategy may improve postoperative outcomes. Additional perioperative precautions are necessary in patients with severe morbid obesity, metabolic syndrome, untreated or severe obstructive sleep apnoea syndrome, or obesity hypoventilation syndrome; patients receiving home ventilatory support or postoperative opioid therapy; and obese patients undergoing open operations, long procedures or revisional surgery.

Performance of Veterinary Services Pathway evolution and One Health aspects

Animals, and the health systems which ensure their protection, play a vital role in the security and economic and social well-being of humanity, and are therefore a key component of the One Health concept. For global and national health security, prevention is better than cure, and targeting 'risk at source' in animal populations is a vital strategy in safeguarding the planet from risks of emerging zoonoses and antimicrobial resistance (AMR). Neglected zoonoses - such as rabies and brucellosis - continue to have a significant global impact on human health and are also best managed at their animal source. The World Organisation for Animal Health (OIE) has built international consensus on the principles of good governance and the quality of Veterinary Services, which are incorporated within its international standards. The OIE has a proven track record in the provision of Member Country support based on these standards, especially since the advent of its flagship Performance of Veterinary Services (PVS) Pathway programme in 2006-2007. To date, approximately 140 countries have benefited from the structured and sustainable process of animal health systems evaluation and planning afforded by the PVS Pathway. The PVS Tool, the basic methodology upon which the PVS Pathway is based, addresses One Health by evaluating the Veterinary Authority's ability to coordinate with other Competent Authorities that have a role to play in One Health, most notably public health, food safety, and environmental authorities. Despite the undoubted success of the PVS Pathway, the OIE felt that it was time to consider how the programme might be developed to adapt to new challenges. Consequently, during 2017-2018, the OIE embarked on a process of PVS evolution, during which it carried out extensive consultation and further tailored the PVS Pathway to a changing global context. These improvements, which include both fundamental adaptations to the PVS Pathway methods and the development of new PVS Pathway activities targeting topics such as multisectoral collaboration, rabies and AMR, have further strengthened and embedded the One Health approach within the PVS Pathway.

Synergising tools for capacity assessment and One Health operationalisation

Multisectoral, One Health collaboration is essential for addressing national and international health threats that arise at the human-animal-environment interface. Thanks to the efforts of multiple organisations, countries now have an array of One Health tools available to assess capacities within and between sectors, plan and prioritise activities, and strengthen multisectoral, One Health coordination, communication, and collaboration. By doing so, they are able to address health threats at the human-animal-environment interface, including emerging zoonotic and infectious diseases, more efficiently. However, to ensure optimal outcomes for the countries using these One Health tools, the partners responsible for implementation should regularly collaborate and share information such as implementation timelines, results and lessons learned, so that one process can inform the next. This paper presents a consensus framework on how commonly implemented One Health tools might align to best support countries in strengthening One Health systems. Twelve One Health tools were selected based on their high implementation rates, authors' experience with these tools and their focus on multisectoral, One Health coordination. Through a four-step process, the authors: a) jointly carried out a landscape analysis of One Health tools, using a Cloudbased spreadsheet to share the unique characteristics and applications of each tool; b) performed an implementation analysis to identify and share implementation dynamics and identify respective outcomes and synergies; c) jointly created a consensus conceptual model of how the authors suggest the tools might logically work together; and d) extrapolated from steps 1-3 an agreed-upon overarching conceptual framework for how current and future One Health tools could be categorised to best support One Health system strengthening at the national level. Highlighted One Health tools include the States Parties Annual Reporting Tool under the International Health Regulations (IHR), the World Organisation for Animal Health Performance of Veterinary Services (PVS) Pathway, the Joint External Evaluation process, IHR/PVS National Bridging Workshops, the Centers for Disease Control and Prevention One Health Zoonotic Disease Prioritization Tool, the Food and Agriculture Organization (FAO) Laboratory Mapping Tool, the FAO Assessment Tool for Laboratories and Antimicrobial Resistance Surveillance Systems, the FAO Surveillance Evaluation Tool, the One Health Systems Mapping and Analysis Resource Toolkit, the National Action Plan for Health Security, and IHR Monitoring and Evaluation Framework tools for After Action Reviews and Simulation Exercises. A new guidance document entitled, Taking a Multisectoral, One Health Approach: A Tripartite Guide to Addressing Zoonotic Diseases in Countries was also included as a framework that provides guidance to support the implementation of the outputs of the tools described.

One Health operations: a critical component in the International Health Regulations Monitoring and Evaluation Framework

Under the International Health Regulations (IHR, 2005), a legally binding document adopted by 196 States Parties, countries are required to develop their capacity to rapidly detect, assess, notify and respond to unusual health events of potential international concern. To support countries in monitoring and enhancing their capacities and complying with the IHR (2005), the World Health Organization (WHO) developed the IHR Monitoring and Evaluation Framework (IHR MEF). This framework comprises four complementary components: the State Party Annual Report, the Joint External Evaluation, after-action reviews and simulation exercises. The first two are used to review capacities and the second two to help to explore their functionality. The contribution of different disciplines, sectors, and areas of work, joining forces through a One Health approach, is essential for the implementation of the IHR (2005). Therefore, WHO, in partnership with the Food and Agriculture Organization of the United Nations (FAO), the World Organisation for Animal Health (OIE), and other international and national partners, has actively worked on facilitating the inclusion of the relevant sectors, in particular the animal health sector, in each of the four components of the IHR MEF. Other tools complement the IHR MEF, such as the WHO/OIE IHR-PVS [Performance of Veterinary Services] National Bridging Workshops, which facilitate the optimal use of the results of the IHR MEF and the OIE Performance of Veterinary Services Pathway and create an opportunity for stakeholders from animal health and human health services to work on the coordination of their efforts. The results of these various tools are used in countries' planning processes and are incorporated in their National Action Plan for Health Security to accelerate the implementation of IHR core capacities. The present article describes how One Health is incorporated in all components of the IHR MEF.

Mapping the genomic landscape of inherited retinal disease genes prioritizes genes prone to coding and noncoding copy-number variations

PurposePart of the hidden genetic variation in heterogeneous genetic conditions such as inherited retinal diseases (IRDs) can be explained by copy-number variations (CNVs). Here, we explored the genomic landscape of IRD genes listed in RetNet to identify and prioritize those genes susceptible to CNV formation.MethodsRetNet genes underwent an assessment of genomic features and of CNV occurrence in the Database of Genomic Variants and literature. CNVs identified in an IRD cohort were characterized using targeted locus amplification (TLA) on extracted genomic DNA.ResultsExhaustive literature mining revealed 1,345 reported CNVs in 81 different IRD genes. Correlation analysis between rankings of genomic features and CNV occurrence demonstrated the strongest correlation between gene size and CNV occurrence of IRD genes. Moreover, we identified and delineated 30 new CNVs in IRD cases, 13 of which are novel and three of which affect noncoding, putative cis-regulatory regions. Finally, the breakpoints of six complex CNVs were determined using TLA in a hypothesis-neutral manner.ConclusionWe propose a ranking of CNV-prone IRD genes and demonstrate the efficacy of TLA for the characterization of CNVs on extracted DNA. Finally, this IRD-oriented CNV study can serve as a paradigm for other genetically heterogeneous Mendelian diseases with hidden genetic variation.

Cryptococcal meningitis presenting as sinusitis in a renal transplant recipient

Cryptococcal meningitis is a relatively common invasive fungal infection in immunocompromised patients, especially in solid organ transplant recipients. Clinical presentation typically includes fever, headache, photophobia, neck stiffness, and/or altered mental status. Unusual presentations may delay diagnosis. Therapy is challenging in renal transplant patients because of the nephrotoxicity associated with amphotericin B, the recommended treatment. We present a case of cryptococcal meningitis in a renal transplant recipient presenting as acute sinusitis with successful treatment using fluconazole as primary therapy.

Complications of non-invasive ventilation techniques: a comprehensive qualitative review of randomized trials

Non-invasive ventilation (NIV) has become a common treatment for acute and chronic respiratory failure. In comparison with conventional invasive mechanical ventilation, NIV has the advantages of reducing patient discomfort, procedural complications, and mortality. However, NIV is associated with frequent uncomfortable or even life-threatening adverse effects, and patients should be thoroughly screened beforehand to reduce potential severe complications. We performed a detailed review of the relevant medical literature for NIV complications. All major NIV complications are potentially life-threatening and can occur in any patient, but are strongly correlated with the degree of pulmonary and cardiovascular involvement. Minor complications can be related to specific structural features of NIV interfaces or to variable airflow patterns. This extensive review of the literature shows that careful selection of patients and interfaces, proper setting of ventilator modalities, and close monitoring of patients from the start can greatly reduce NIV complications.

Effects of tracheal intubation on ventilation with LMA classic for percutaneous dilation tracheostomy

AIM

The classic laryngeal mask airway (cLMATM) can be used in place of an endotracheal tube (ETT) as the ventilatory device during percutaneous dilational tracheostomy (PDT). We aimed to investigate the possible loss of efficacy of cLMATM after tracheal intubation.

METHODS

Severity of laryngeal lesions and efficacy of cLMATM were determined in two groups of thirty patients each who were switched from ETT ventilation to cLMA ventilation for PDT after a short (<4 days) or a long (>12 days) tracheal intubation.

RESULTS

cLMATM allowed us to carry out PDT in all patients. Short tracheal intubations resulted in mild lesions of the larynx and mild gas leaks during cLMATM ventilation. Longer intubations caused moderate-to-severe (P<0.05) lesions of the larynx and larger gas leaks. A single complication occurred in one patient post-procedurally and in no patient at 6-month follow-up.

CONCLUSION

Efficacy of cLMATM was maintained after short tracheal intubation and decreased after long intubation.

Subarachnoid anesthesia for loco-regional antiblastic perfusion with circulatory block (stop-flow perfusion)

AIM

Loco-regional antiblastic perfusion with circulatory block (stop-flow perfusion, SFP) is a procedure designed to treat solid tumors of the limb and pelvis in an advanced stage, like melanoma, sarcoma of the soft tissues and colon-rectal cancer. The aim of this study was to evaluate if subarachnoid anesthesia could represent a safe and suitable anesthetic technique for this procedure.

METHODS

Thirty SFP procedures were performed in the angiographic room, 15 for the treatment of lower-limb neoplasias and 15 for pelvic neoplasias. The patients (ASA I-III) had a mean age of 59.1 years (range: 19-81 years). The patients were given different dosages of bupivacaine (range: 10-20 mg) in hyperbaric solution at the concentration of 0.5% and 1% by lumbar subarachnoid injection at different levels (from T12-L1 to L3-L4). Standard monitoring was set up (ECG, pulse-oximetry, and non-invasive artery pressure). The use of any anesthetic and analgesic drug, eventually used in the intra- or postoperative period, was recorded.

RESULTS

The lumbar puncture was approached at L1-L2 and L2-L3 levels in 80% of the cases. Doses of bupivacaine between 12 mg and 14 mg were administered in 2/3 of the cases. Bupivacaine was formulated in hyperbaric solution and administered at a concentration of 0.5% (8 patients) or 1% (22 patients). Complica-tions related to the anesthetic technique were absent. Intraoperative pain control was almost complete with one exception, when the procedure lasted unusually long. Pain control was satisfying immediately after the procedure as well: only in 3 cases were non-opiod analgesics administered within the first 6 h.

CONCLUSIONS

Spinal subarachnoid anesthesia has proven to be an effective, safe, and easy-to-manage technique for carrying out SFP procedure in a non-conventional environment such as an angiographic room. It was free of serious side effects and well tolerated even in patients in poor general conditions.

Assessment of tissue viability in frostbite by 99mTc pertechnetate scintigraphy

Technetium-99m pertechnetate scintigraphy was performed in the involved extremities of six patients with severe frostbite of the hands (six cases) and feet (one case). There was good correlation between the scintigraphic findings and the extent of deep tissue ultimately requiring surgical resection. Technetium-99m pertechnetate imaging distinguishes viable from dead tissue in frostbite in a simple, noninvasive manner, and findings are easy to interpret. A persistent perfusion defect is seen in nonviable tissue.