Older and wiser: The benefits to neonates of aged neutrophils.

Neonates are relatively protected from non-neonatal pathogens by unclear mechanisms. In this issue of Immunity, Bee et al.1 show that resistance to Streptococcus pneumoniae in neonatal mice is mediated by dampened neutrophil efferocytosis, accumulation of aged neutrophils, and enhanced CD11b-dependent bacterial opsonophagocytosis.

Engineering Fiber-Based Nervous Tissue Constructs for Axon Regeneration.

Biomaterial-based scaffolds used in nerve conduits including channels for confining regenerating axons and 3-dimensional (3D) gels as substrates for growth have made improvements in models of nerve repair. Many biomaterial strategies, however, continue to fall short of autologous nerve grafts, which remain the current gold standard in repairing severe nerve lesions (<20 mm). Intraluminal nerve conduit fibers have also shown considerable promise in directing regenerating axons in vitro and in vivo and have gained increasing interest for nerve repair. It is unknown, however, how growing axons respond to a fiber when encountered in a 3D environment. In this study, we considered a construct consisting of a compliant collagen hydrogel matrix and a fiber component to assess contact-guided axon growth. We investigated preferential axon outgrowth on synthetic and natural polymer fibers by utilizing small-diameter microfibers of poly-L-lactic acid and type I collagen representing 2 different fiber stiffnesses. We found that axons growing freely in a 3D hydrogel culture preferentially attach, turn and follow fibers with outgrowth rates and distances that far exceed outgrowth in a hydrogel alone. Wet-spun type I collagen from rat tail tendon performed the best, associated with highly aligned and accelerated outgrowth. This study also evaluated the response of dorsal root ganglion neurons from adult rats to provide data more relevant to axon regenerative potential in nerve repair. We found that ECM treatments on fibers enhanced the regeneration of adult axons indicating that both the physical and biochemical presentation of the fibers are essential for enhancing axon guidance and growth.

The accuracy of pre-appendectomy computed tomography with histopathological correlation: a clinical audit, case discussion and evaluation of the literature.

The increasing use of computed tomography (CT) in acute appendicitis makes recognising the radiological hallmarks of the condition and its mimics vital. The differential diagnosis includes both appendiceal and nonappendiceal pathologies. The correlation between pre-appendectomy CT and post-appendectomy histopathology was audited retrospectively. Cases of clinico-histopathological discrepancy underwent blind peer-review, and possible improvements were discussed in the context of the medical literature. A grade for discrepancy was given based on the RADPEER scoring system, and interesting or discrepant cases were examined more closely to identify targets for education. Of the 199 procedures, 4 appendectomies were negative (histologically normal), 182 were positive (primary appendicitis) and 13 were incidental (another primary process caused inflammation). The positive predictive value for pre-appendectomy CT was 91.5 %, and the negative appendectomy rate was 2 %. There were many secondary pathologies, including neoplasia, tuberculosis and endometriosis. Although no CT reports missed a diagnosis that should be made "almost all of the time" and in 96 % of cases, the second, blinded radiologist agreed with the initial assessment, in 3 cases, a missed diagnosis altered clinical management; 2 were "understandable" misses but 1 was not. In five cases, a discrepancy was "understandable" but clinically insignificant. Overall, in comparison to the medical literature, the degree of clinico-histopathological correlation was good. Although identifying areas for improvement was challenging, after a pictorial review of four cases and a discussion of the medical literature, we present our audit results and some valuable learning points for use in the CT assessment of suspected acute appendicitis.

Functional 3-D cardiac co-culture model using bioactive chitosan nanofiber scaffolds.

The in vitro generation of a three-dimensional (3-D) myocardial tissue-like construct employing cells, biomaterials, and biomolecules is a promising strategy in cardiac tissue regeneration, drug testing, and tissue engineering applications. Despite significant progress in this field, current cardiac tissue models are not yet able to stably maintain functional characteristics of cardiomyocytes for long-term culture and therapeutic purposes. The objective of this study was to fabricate bioactive 3-D chitosan nanofiber scaffolds using an electrospinning technique and exploring its potential for long-term cardiac function in the 3-D co-culture model. Chitosan is a natural polysaccharide biomaterial that is biocompatible, biodegradable, non-toxic, and cost effective. Electrospun chitosan was utilized to provide structural scaffolding characterized by scale and architectural resemblance to the extracellular matrix (ECM) in vivo. The chitosan fibers were coated with fibronectin via adsorption in order to enhance cellular adhesion to the fibers and migration into the interfibrous milieu. Ventricular cardiomyocytes were harvested from neonatal rats and studied in various culture conditions (i.e., mono- and co-cultures) for their viability and function. Cellular morphology and functionality were examined using immunofluorescent staining for alpha-sarcomeric actin (SM-actin) and gap junction protein, Connexin-43 (Cx43). Scanning electron microscopy (SEM) and light microscopy were used to investigate cellular morphology, spatial organization, and contractions. Calcium indicator was used to monitor calcium ion flux of beating cardiomyocytes. The results demonstrate that the chitosan nanofibers retained their cylindrical morphology in long-term cell cultures and exhibited good cellular attachment and spreading in the presence of adhesion molecule, fibronectin. Cardiomyocyte mono-cultures resulted in loss of cardiomyocyte polarity and islands of non-coherent contractions. However, the cardiomyocyte-fibroblast co-cultures resulted in polarized cardiomyocyte morphology and retained their morphology and function for long-term culture. The Cx43 expression in the fibroblast co-culture was higher than the cardiomyocytes mono-culture and endothelial cells co-culture. In addition, fibroblast co-cultures demonstrated synchronized contractions involving large tissue-like cellular networks. To our knowledge, this is the first attempt to test chitosan nanofiber scaffolds as a 3-D cardiac co-culture model. Our results demonstrate that chitosan nanofibers can serve as a potential scaffold that can retain cardiac structure and function. These studies will provide useful information to develop a strategy that allows us to generate engineered 3-D cardiac tissue constructs using biocompatible and biodegradable chitosan nanofiber scaffolds for many tissue engineering applications.

Predictors of morbidity and in-hospital mortality following procedure-related cardiac tamponade.

Background: Cardiac tamponade (CT) can be a complication following invasive cardiac procedures. We assessed CT following common cardiac electrophysiology (EP) procedures to facilitate risk prediction of associated morbidity and in-hospital mortality. Methods: Patients who underwent various EP procedures in the cardiac catheterization lab (ablations and device implantations) were identified using the International Classification of Diseases, Ninth and Tenth Edition, Clinical Modification (ICD-9-CM and ICD-10-CM, respectively) from the Nationwide Inpatient Sample (NIS) database. Patient demographics, presence of comorbidities, CT-related events, and in-hospital death were also abstracted from the NIS database. Results: The frequency of CT-related events in patients with EP intervention from 2010 to 2017 ranged from 3.4% to 7.0%. In-hospital mortality related to CT-related events was found to be 2.2%. Increasing age was the only predictor of higher mortality in atrial fibrillation (AF) ablation and cardiac resynchronization therapy (CRT) groups (OR [95% CI]: AF ablation = 11.15 [1.70-73.34], p = .01; CRT = 1.41 [1.05-1.90], p = .02). Conclusions: In the real-world setting, CT-related events in EP procedures were found to be 3.4%-7.0% with in-hospital mortality of 2.2%. Older patients undergoing AF ablation were found to have higher mortality.

Incidentally discovered distant cutaneous metastasis of sacral chordoma: a case with variation in S100 protein expression (compared to the primary tumor) and review of the literature.

Chordomas represent rare malignant primary bone tumors most often occurring in the sacral area. These tumors uncommonly involve the skin and often follow a progressive course with multiple recurrences, metastases and eventual death. Reports of cutaneous metastases from chordoma are very rare. The immunohistochemical staining characteristics of these cutaneous metastases with comparison to the primary tumors are similarly rarely addressed in the literature. We report a rare case of incidentally discovered, small, solitary distant cutaneous metastasis of sacral chordoma that developed on the right upper back of a 44-year-old man with a history of multiple completely excised melanomas who had also been previously diagnosed with chordoma involving the sacrum 12 years earlier. We describe its pathologic features with comparison to the primary tumor and briefly review the literature. Immunohistochemically, the cutaneous metastasis and primary tumor both stained positively for pancytokeratin and vimentin, as expected. However, the cutaneous metastasis unexpectedly lacked S100 protein expression, whereas the primary tumor was S100 positive. This phenomenon has only been documented in one other case report. We demonstrate that late, incidentally discovered cutaneous metastasis with unexpected immunohistochemical staining features rarely occur and can present a diagnostic challenge.

Identifying and managing functional cardiac symptoms.

Recurring chest pain and other cardiac symptoms that cannot be adequately explained by organic pathology are common and can be associated with substantial disability, distress and high healthcare costs. Common mental disorders such as depression and anxiety frequently co-occur with these symptoms and, in some cases, account for their presentation, although they are not universally present. Due to the frequency of functional cardiac presentations and risks of iatrogenic harm, physicians should be familiar with strategies to identify, assess and communicate with patients about these symptoms. A systematic and multidisciplinary approach to diagnosis and management is often needed. Health beliefs, concerns and any associated behaviours should be elicited and addressed throughout. Psychiatric comorbidities should be concurrently identified and treated. For those with persistent symptoms, psychosocial outcomes can be poor, highlighting the need for further research and investment in diagnostic and therapeutic approaches and multidisciplinary service models.

Statin prescription and CV risk assessment in adult psychiatric outpatients with intellectual disability.

We performed a single-centre study to assess the risk of cardiovascular disease (CVD) in psychiatry outpatients with intellectual disability (ID) using the QRISK-3 score. There were 143 patients known to the ID psychiatry clinic enrolled. Of these, 28 (19.6%) had elevated CVD risk - defined as 10-year risk of heart attack or stroke of ≥10%. Of these, 57.1% were not prescribed statin therapy, which - after lifestyle measures - is recommended by National Institute for Health and Care Excellence (NICE) guidelines. The mean QRISK-3 score was 6.31% (95% confidence interval [CI] 4.84 to 7.78), with a relative risk of 3.50 (95%CI 2.34 to 4.67) compared with matched controls. The high CVD risk identified in this study supports routine CVD risk assessment and management in adult outpatients with ID. Appropriate lifestyle measures and statin therapy could help reduce the excess CVD-related morbidity and mortality in ID patients.

Evaluating the cytocompatibility and differentiation of bone progenitors on electrospun zein scaffolds.

Bone fractures often result in complications that require surgical intervention to promote fracture healing. Tissue engineering seeks to alleviate the need for autologous bone grafting by utilizing scaffolds that can promote bone fracture healing. Plant-derived materials are desirable biomaterials because of their biodegradability, availability, and low immunogenicity. Among various plant-derived proteins, zein, which is a corn protein, has shown promise for bone repair. However, when processed, zein is often blended with synthetic materials to improve mechanical properties and overall hydrolytic stability. In this study, pure zein was electrospun to create fibrous scaffolds and cross-linked with trimethylolpropane triglycidyl ether to improve hydrolytic stability. Scaffolds were characterized and evaluated in vitro for promoting the osteogenic differentiation of MC3T3-E1 cells, which are bone progenitor cells. Cross-linked zein scaffolds retained their uniform fiber morphologies after hydration. MC3T3-E1 cells grew and differentiated on the zein scaffolds even in the absence of induction factors, as demonstrated by increased alkaline phosphatase activity, mineralization, and early upregulation of Runx2 gene expression, a transcription factor associated with osteoblast differentiation. These studies demonstrate that stable, zein fibrous scaffolds could have potential for use in bone repair applications.

COVID-19 pandemic and STEMI: pathway activation and outcomes from the pan-London heart attack group.

OBJECTIVES: To understand the impact of COVID-19 on delivery and outcomes of primary percutaneous coronary intervention (PPCI). Furthermore, to compare clinical presentation and outcomes of patients with ST-segment elevation myocardial infarction (STEMI) with active COVID-19 against those without COVID-19. METHODS: We systematically analysed 348 STEMI cases presenting to the PPCI programme in London during the peak of the pandemic (1 March to 30 April 2020) and compared with 440 cases from the same period in 2019. Outcomes of interest included ambulance response times, timeliness of revascularisation, angiographic and procedural characteristics, and in-hospital clinical outcomes RESULTS: There was a 21% reduction in STEMI admissions and longer ambulance response times (87 (62-118) min in 2020 vs 75 (57-95) min in 2019, p<0.001), but that this was not associated with a delays in achieving revascularisation once in hospital (48 (34-65) min in 2020 vs 48 (35-70) min in 2019, p=0.35) or increased mortality (10.9% (38) in 2020 vs 8.6% (38) in 2019, p=0.28). 46 patients with active COVID-19 were more thrombotic and more likely to have intensive care unit admissions (32.6% (15) vs 9.3% (28), OR 5.74 (95%CI 2.24 to 9.89), p<0.001). They also had increased length of stay (4 (3-9) days vs 3 (2-4) days, p<0.001) and a higher mortality (21.7% (10) vs 9.3% (28), OR 2.72 (95% CI 1.25 to 5.82), p=0.012) compared with patients having PPCI without COVID-19. CONCLUSION: These findings suggest that PPCI pathways can be maintained during unprecedented healthcare emergencies but confirms the high mortality of STEMI in the context of concomitant COVID-19 infection characterised by a heightened state of thrombogenicity.

Paired surveys for patients and physiologists in echocardiography: a single-centre experience.

The British Society of Echocardiography (BSE) highlights the importance of patient questionnaires as part of the quality improvement process, To this end, we implemented a novel system whereby paired surveys were completed by patients and physiologists for transthoracic echocardiography scans, allowing for parallel comparison of the experiences of service providers and end users. Anonymised questionnaires were completed for each scan by the patient and physiologist for outpatient echocardiographic scans in a teaching hospital. In 26% of the responses, patient found the scans at least slightly painful, and in 24% of scans physiologists were in discomfort. The most common reason given by physiologists for technically difficult or inadequate scans was patient discomfort. In 38% of the scans at least one person (the patient or the physiologist) was in at least some discomfort. Comparative data showed that the scans reported as most painful by patients were also reported by the physiologists as difficult and uncomfortable. In summary, these results demonstrate the feasibility of implementing paired surveys. Patient information leaflets by the BSE and National Health Service (NHS) describe echocardiography as painless but the results here indicate this is not always the case.

Investigation of glycosaminoglycan mimetic scaffolds for neurite growth.

Spinal cord injury can lead to severe dysfunction as a result of limited nerve regeneration that is due to an inhibitory environment created at the site of injury. Neural tissue engineering using materials that closely mimic the extracellular matrix (ECM) during neural development could enhance neural regeneration. Glycosaminoglycans (GAGs), which are sulfated polysaccharides, have been shown to modulate axonal outgrowth in neural tissue depending upon the position and degree of sulfation. Cellulose sulfate (CelS), which is a GAG mimetic, was evaluated for its use in promoting neurite extension. Aligned fibrous scaffolds containing gelatin blended with 0.25% partially sulfated cellulose sulfate (pCelS), having sulfate predominantly at the 6-carbon position of the glucose monomer unit, and fully sulfated cellulose sulfate (fCelS), which is sulfated at the 2-, 3-, and 6-carbon positions of the glucose monomer unit, were fabricated using the electrospinning method. Comparisons were made with scaffolds containing native GAGs, chondroitin sulfate-A (CS-A) and chondroitin sulfate-C (CS-C), which were obtained from commercial sources. CS-A and CS-C are present in neural tissue ECM. The degree of sulfation and position of sulfate groups was determined using elemental analysis, Fourier-transform infrared spectroscopy (FTIR), Raman microspectroscopy, and 13C nuclear magnetic resonance (NMR). In vitro studies examined both nerve growth factor (NGF) binding on scaffolds and neurite extension by dorsal root ganglion (DRG) neurons. NGF binding was highest on scaffolds containing pCelS and fCelS. Neurite extension was greatest for scaffolds containing fCelS followed by pCelS, with the lowest outgrowth on the CS-A containing scaffolds, suggesting that the degree and position of sulfation of CelS was permissible for neurite outgrowth. This study demonstrated that cellulose sulfate, as a GAG mimetic, could be used for future neural tissue regeneration application. STATEMENT OF SIGNFICANCE: Scaffolds that closely mimic the native extracellular matrix (ECM) during development may be a promising approach to enhance neural regeneration. Here, we reported a glycosaminoglycan (GAG) mimetic derived from cellulose that promotes neurite extension over native GAGs, chondroitin sulfate-A (CS-A) and chondroitin sulfate-C (CS-C), which are present in neural ECM. Depending upon the degree and position of sulfation, the GAG mimetic can impact nerve growth factor binding and permissive neurite outgrowth.

Molecular modeling directed by an interfacial test apparatus for the evaluation of protein and polymer ingredient function in situ.

A simplified apparatus is described that measures the damping of a suspended measuring device. The movement of the device (bob) is damped by the properties of the air-water surface adsorbed material. Its value lies in describing the surface chemomechanical properties of ingredients and excipients used in food, nutraceutical, cosmetic (cosmeceutical), and natural drug-food product formulations that traverse the food sciences. Two surfactants, two food and drug-grade polymers, and five naturally occurring food and serum proteins were tested and used to estimate and model interfacial viscoelasticity. Equilibration times of >15 min were found to give sufficiently stable interfaces for routine assessment. The viscoelasticity of the air-water interface was estimated with reference to model solutions. These model solutions and associated self-assembled interfacial nanostructured adsorbed layers were fabricated using a preliminary screening process with the aid of a specialized foaming apparatus ( C(300) values), surface tension measurements (23-73 mN/m), and referential surface shear and dilation experiments. The viscoelasticity measured as a percentage of surface damping ( D) of a pendulum was found to range from 1.0 to 22.4% across the samples tested, and this represented interfacial viscosities in the range of 0-4630 microNs/m. The technique can distinguish between interfacial compositions and positions itself as an easily accessible valuable addition to tensiometric and analytical biochemistry-based techniques.

* Gelatin Scaffolds Containing Partially Sulfated Cellulose Promote Mesenchymal Stem Cell Chondrogenesis.

Articular cartilage has a limited capacity to heal after damage from injury or degenerative disease. Tissue engineering constructs that more closely mimic the native cartilage microenvironment can be utilized to promote repair. Glycosaminoglycans (GAGs), a major component of the cartilage extracellular matrix, have the ability to sequester growth factors due to their level and spatial distribution of sulfate groups. This study evaluated the use of a GAG mimetic, cellulose sulfate, as a scaffolding material for cartilage tissue engineering. Cellulose sulfate can be synthesized to have a similar level and spatial distribution of sulfates as chondroitin sulfate C (CSC), the naturally occurring GAG. This partially sulfated cellulose (pSC) was incorporated into a fibrous gelatin construct by the electrospinning process. Scaffolds were characterized for fiber morphology and overall stability over time in an aqueous environment, growth factor interaction, and for supporting mesenchymal stem cell (MSC) chondrogenesis in vitro. All scaffold groups had micron-sized fibers and maintained overall stability in aqueous environments. Increasing concentrations of the transforming growth factor-beta 3 (TGF-ß3) were detected on scaffolds with increasing pSC. MSC chondrogenesis was enhanced on the scaffold with the highest pSC concentration as seen with the highest collagen type II production, collagen type II immunostaining, expression of cartilage-specific genes, and ratio of collagen type II to collagen type I production. These studies demonstrated the potential of pSC sulfate as a scaffolding material for cartilage tissue engineering.