Specific Genetic Polymorphisms Contributing in Differential Binding of Gliadin Peptides to HLA-DQ and TCR to Elicit Immunogenicity in Celiac Disease

Immunogenicity of gliadin peptides in celiac disease (CD) is majorly determined by the pattern of molecular interactions with HLA-DQ and T-cell receptors (TCR). Investigation of the interactions between immune-dominant gliadin peptides, DQ protein, and TCR are warranted to unravel the basis of immunogenicity and variability contributed by the genetic polymorphisms. Homology modeling of HLA and TCR done using Swiss Model and iTASSER, respectively. Molecular interactions of eight common deamidated immune-dominant gliadin with HLA-DQ allotypes and specific TCR gene pairs were evaluated. Docking of the three structures was performed with ClusPro2.0 and ProDiGY was used to predict binding energies. Effects of known allelic polymorphisms and reported susceptibility SNPs were predicted on protein-protein interactions. CD susceptible allele, HLA-DQ2.5 was shown to have considerable binding affinity to 33-mer gliadin (ΔG = - 13.9; Kd = 1.5E - 10) in the presence of TRAV26/TRBV7. Higher binding affinity was predicted (ΔG = - 14.3, Kd = 8.9E - 11) when TRBV28 was replaced with TRBV20 paired with TRAV4 suggesting its role in CD predisposition. SNP rs12722069 at HLA-DQ8 that codes Arg76α forms three H-bonds with Glu12 and two H-bonds with Asn13 of DQ2 restricted gliadin in the presence of TRAV8-3/TRBV6. None of the HLA-DQ polymorphisms was found to be in linkage disequilibrium with reported CD susceptibility markers. Haplotypic presentations of rs12722069-G, rs1130392-C, rs3188043-C and rs4193-A with CD reported SNPs were observed in sub-ethnic groups. Highly polymorphic sites of HLA alleles and TCR variable regions could be utilized for better risk prediction models in CD. Therapeutic strategies by identifying inhibitors or blockers targeting specific gliadin:HLA-DQ:TCR binding sites could be investigated.

Tissue engineering of human ear pinna

Auricular deformities (Microtia) can cause physical, social as well as psychological impacts on a patient's wellbeing. Biofabrication of a complex structure such as ear pinna is not precise with currently available techniques. These limitations can be overcome with the help of tissue engineering. In this article, the authors presented molding and three dimensional (3D) printing to generate a flexible, human size ear pinna. The decellularization of goat ear cartilage protocol and bioink alkaline digestion protocol was followed to yield complete removal of all cellular components without changing the properties of the Extra Cellular Matrix (ECM). Decellularized scaffold used in molding technology and 3D printing technology Computer-Aided Design /Stereolithography (CAD/STL) uses bioink to construct the patient-specific ear. In vivo biocompatibility of the both ear pinnae showed demonstrable recellularization. Histology and scanning electron microscopy analysis revealed the recellularization of cartilage-specific cells and the development of ECM in molded and 3D printed ear pinna after transplantation. Both the techniques provided ideal results for mechanical properties such as elasticity. Vascular Associated Protein expression revealed specific vasculogenic pattern (angiogenesis) in transplanted molded pinna. Chondrocyte specific progenitor cells express CD⁹⁰⁺ which highlighted newly developed chondrocytes in both the grafts which indicated that the xenograft was accepted by the rat. Transplantation of molded as well as 3D ear pinna was successful in an animal model and can be available for clinical treatments as a medical object to cure auricular deformities.

Point-of-care lung ultrasound in the assessment of COVID-19: results of a UK multicentre service evaluation

BACKGROUND

Coronavirus disease 2019 has had a dramatic impact on the delivery of acute care globally. Accurate risk stratification is fundamental to the efficient organisation of care. Point-of-care lung ultrasound offers practical advantages over conventional imaging with potential to improve the operational performance of acute care pathways during periods of high demand. The Society for Acute Medicine and the Intensive Care Society undertook a collaborative evaluation of point-of-care imaging in the UK to describe the scope of current practice and explore performance during real-world application.

METHODS

A retrospective service evaluation was undertaken of the use of point-of-care lung ultrasound during the initial wave of coronavirus infection in the UK. We report an evaluation of all imaging studies performed outside the intensive care unit. An ordinal scale was used to measure the severity of loss of lung aeration. The relationship between lung ultrasound, polymerase chain reaction for SARS-CoV-2 and 30-day outcomes were described using logistic regression models.

RESULTS

Data were collected from 7 hospitals between February and September 2020. In total, 297 ultrasound examinations from 295 patients were recorded. Nasopharyngeal swab samples were positive in 145 patients (49.2% 95%CI 43.5-54.8). A multivariate model combining three ultrasound variables showed reasonable discrimination in relation to the polymerase chain reaction reference (AUC 0.77 95%CI 0.71-0.82). The composite outcome of death or intensive care admission at 30 days occurred in 83 (28.1%, 95%CI 23.3-33.5). Lung ultrasound was able to discriminate the composite outcome with a reasonable level of accuracy (AUC 0.76 95%CI 0.69-0.83) in univariate analysis. The relationship remained statistically significant in a multivariate model controlled for age, sex and the time interval from admission to scan Conclusion: Point-of-care lung ultrasound is able to discriminate patients at increased risk of deterioration allowing more informed clinical decision making.

3D printing of human ear pinna using cartilage specific ink

Biofabrication of a complex structure such as ear pinna is not precise with currently available techniques. Auricular deformities (e.g. microtia) can cause physical, social as well as psychological impacts on a patient's wellbeing. Currently available surgical techniques and transplantation methods have many limitations that can be overcome with the help of 3D bioprinting technology. Printable bioink enriched with cartilage-specific extracellular matrix (ECM) synthesis was done by digesting goat ear pinna cartilage and polymerized by adding polyvinyl alcohol and gelatine. Rheological analysis and Fourier-transform infrared spectroscopy were used for the characterization of bioink to get desired viscosity and polymerization. Human ear pinna was printed using extrusion method and computer-aided design, stereolithography software which facilitated the automated printing in relatively less time without continuous monitoring. Thermal degradation of pinna was checked by thermal gravimetric analysis. Biodegradability and swelling of ear pinna were observed for understanding the nature of pinna and the impact of external factors. Reconstructed pinna's biocompatibility was proved byin ovoandin vivostudies. The occurrence of angiogenesis in the grafted ear manifested the capacity of proliferation and engraftment of cartilage cells. Histology and SEM analysis revealed the recellularization and the synthesis of ECM components such as glycosaminoglycan and collagen in transplanted 3D printed ear pinna. The expression of CD90+ which indicated newly synthesized cartilage in the transplanted 3D printed ear pinna. The absence expression of CD14+ also indicated acceptance of xenogenic transplanted 3D printed ear pinna. Transplantation of 3D ear pinna was successful in an animal model and can be utilized as tissue engineered ear bank.

The Use of Lung Ultrasound in Acute Medicine

POCUS (Point of Care Ultrasound) refers to ultrasound performed by clinicians as part of their initial patient evaluation, often with the aim of answering a specific question as opposed to being a comprehensive assessment. Such ultrasound is noninvasive, involves no radiation and can be rapidly performed at the bedside. It is also widely practiced in emergency and intensive care medicine leading to earlier and more accurate diagnoses for a wide range of presentations such as shock, renal failure and dyspnoea.

Incorporating point-of-care ultrasound into daily intensive care unit rounds: Another source of interruptions?

Point-of-care ultrasound (POCUS) is the use of bedside ultrasonography by the treating clinician, incorporating those images into direct clinical decisions. While there are a number of different techniques and training pathways in this relatively new modality, there has been little discussion around the logistics of integrating POCUS into the standard critical care "business day" of ward rounds, procedures and meetings. This article explores some of these aspects and presents data from an online survey of POCUS practitioners.

Author response

We share your understanding that fluid responsiveness is NOT equivalent to hypovolaemia, and that it also does not equate to fluid administration being of benefit. We offer our apologies should our article have suggested otherwise. Indeed, this is one of the key reasons why we advocate fluid administration against measurable goals, such as stroke volume, as well as blood pressure and pulse.

Assessment of Fluid responsiveness in the Acute Medical Patient and the Role of Echocardiography

Both hyper and hypovolaemia have been associated with poor outcomes. Assessment of fluid responsiveness is challenging in the acute medical patient, due to time constraints, limited evidence and quite often the lack of accurate assessment tools on the Acute Medicine Unit (AMU). This article explains how focused echo assessment is quick and easy to use for this purpose on the acute medical take and highlights key principles to bear in mind when assessing for hypovolaemia and whether to administer fluid therapy. The increasing familiarity with focused echo such as Focused Intensive Care Echocardiography (FICE) and Point Of Care Ultrasound (POCUS) makes extension of these skill sets to assess for fluid responsiveness a relatively straightforward next step for acute physicians.