Correction: Freitas et al. Bacterial Cellulose/Tomato Puree Edible Films as Moisture Barrier Structures in Multicomponent Foods. Foods 2022, 11, 2336.

In the original publication [...].

Bacterial Cellulose/Tomato Puree Edible Films as Moisture Barrier Structures in Multicomponent Foods.

Edible films have been studied mainly as primary packaging materials, but they may be used as barrier layers between food components, e.g., by reducing the moisture migration between components with contrasting water activities. Since edible films are part of the food itself, components adding sensory appeal (e.g., fruit purees) are usually desirable. The objective of this study was to develop a film to be applied as a moisture barrier between nachos and guacamole. Ten film formulations were prepared according to a simplex centroid design with three components-a polysaccharide matrix (consisting of a 5:1 mixture of bacterial cellulose-BC-and carboxymethyl cellulose), tomato puree (for sensory appeal), and palm olein (to reduce hydrophilicity)-and produced by bench casting. The film with the highest palm olein content (20%) presented the lowest water vapor permeability, and its formulation was used to produce a film by continuous casting. The film was applied as a layer between nachos and guacamole, and presented to 80 panelists. The film-containing snack was preferred and considered as crispier when compared to the snack without the film, suggesting that the film was effective in reducing the moisture migration from the moist guacamole to the crispy nachos.

Suitability of Marine- and Porcine-Derived Collagen Type I Hydrogels for Bioprinting and Tissue Engineering Scaffolds.

Collagens from a wide array of animals have been explored for use in tissue engineering in an effort to replicate the native extracellular environment of the body. Marine-derived biomaterials offer promise over their conventional mammalian counterparts due to lower risk of disease transfer as well as being compatible with more religious and ethical groups within society. Here, collagen type I derived from a marine source (Macruronus novaezelandiae, Blue Grenadier) is compared with the more established porcine collagen type I and its potential in tissue engineering examined. Both collagens were methacrylated, to allow for UV crosslinking during extrusion 3D printing. The materials were shown to be highly cytocompatible with L929 fibroblasts. The mechanical properties of the marine-derived collagen were generally lower than those of the porcine-derived collagen; however, the Young's modulus for both collagens was shown to be tunable over a wide range. The marine-derived collagen was seen to be a potential biomaterial in tissue engineering; however, this may be limited due to its lower thermal stability at which point it degrades to gelatin.

Variation in Hydrogel Formation and Network Structure for Telo-, Atelo- and Methacrylated Collagens.

As the most abundant protein in the extracellular matrix, collagen has become widely studied in the fields of tissue engineering and regenerative medicine. Of the various collagen types, collagen type I is the most commonly utilised in laboratory studies. In tissues, collagen type I forms into fibrils that provide an extended fibrillar network. In tissue engineering and regenerative medicine, little emphasis has been placed on the nature of the network that is formed. Various factors could affect the network structure, including the method used to extract collagen from native tissue, since this may remove the telopeptides, and the nature and extent of any chemical modifications and crosslinking moieties. The structure of any fibril network affects cellular proliferation and differentiation, as well as the overall modulus of hydrogels. In this study, the network-forming properties of two distinct forms of collagen (telo- and atelo-collagen) and their methacrylated derivatives were compared. The presence of the telopeptides facilitated fibril formation in the unmodified samples, but this benefit was substantially reduced by subsequent methacrylation, leading to a loss in the native self-assembly potential. Furthermore, the impact of the methacrylation of the collagen, which enables rapid crosslinking and makes it suitable for use in 3D printing, was investigated. The crosslinking of the methacrylated samples (both telo- and atelo-) was seen to improve the fibril-like network compared to the non-crosslinked samples. This contrasted with the samples of methacrylated gelatin, which showed little, if any, fibrillar or ordered network structure, regardless of whether they were crosslinked.

Shaping collagen for engineering hard tissues: Towards a printomics approach.

Hard tissue engineering has evolved over the past decades, with multiple approaches being explored and developed. Despite the rapid development and success of advanced 3D cell culture, 3D printing technologies and material developments, a gold standard approach to engineering and regenerating hard tissue substitutes such as bone, dentin and cementum, has not yet been realised. One such strategy that differs from conventional regenerative medicine approach of other tissues, is the in vitro mineralisation of collagen templates in the absence of cells. Collagen is the most abundant protein within the human body and forms the basis of all hard tissues. Once mineralised, collagen provides important support and protection to humans, for example in the case of bone tissue. Multiple in vitro fabrication strategies and mineralisation approaches have been developed and their success in facilitating mineral deposition on collagen to achieve bone-like scaffolds evaluated. Critical to the success of such fabrication and biomineralisation approaches is the collagen template, and its chemical composition, organisation, and density. The key factors that influence such properties are the collagen processing and fabrication techniques utilised to create the template, and the mineralisation strategy employed to deposit mineral on and throughout the templates. However, despite its importance, relatively little attention has been placed on these two critical factors. Here, we critically examine the processing, fabrication and mineralisation strategies that have been used to mineralise collagen templates, and offer insights and perspectives on the most promising strategies for creating mineralised collagen scaffolds. STATEMENT OF SIGNIFICANCE: In this review, we highlight the critical need to fabricate collagen templates with advanced processing techniques, in a manner that achieves biomimicry of the hierarchical collagen structure, prior to utilising in vitro mineralisation strategies. To this end, we focus on the initial collagen that is selected, the extraction techniques used and the native fibril forming potential retained to create reconstituted collagen scaffolds. This review synthesises current best practises in material sourcing, processing, mineralisation strategies and fabrication techniques, and offers insights into how these can best be exploited in future studies to successfully mineralise collagen templates.

Effect of bolus administration of non-ionic radiopaque contrast media on blood pressure variation.

INTRODUCTION: Haemodynamic changes may occur with the rapid intravenous injection of contrast media due to the osmolality of such pharmaceuticals. This study sought to evaluate the effect of bolus administration of intravenous contrast media on blood pressure variation during the Contrast-Enhanced Computed Tomography (CECT) of the abdomen. METHODS: The study included 74 patients who underwent abdominal CECT and they were placed in the first group receiving a maximum of 80 ml of iodinated contrast via pressure injector (4 ml/s). A further 74 patients, who underwent non-contrast enhanced abdominal CT, were placed in the second group in which 80 ml of normal saline was administered via the same manner. Patients with hypertension and who were on anti-hypertensive drugs were excluded from the study. Non-invasive blood pressure was monitored before the injection of contrast media/saline and immediately after the portal venous phase for the CECT scan and after 45 s following the administration of normal saline in the non-contrast CT group. Mean systolic and diastolic blood pressures from both groups were compared to find out the effect of contrast bolus administration on blood pressure variation. RESULTS: Both systolic and diastolic blood pressure increased with the injection of contrast media among CECT scan group. No significant changes in systolic and diastolic blood pressure were found before and after the scan in the non-contrast group. CONCLUSION: Bolus administration of 80 ml saline has no effect on blood pressure. The increased blood pressure in contrast enhanced studies was induced by the iodinated contrast media and not by the bolus effect.

Aberrant activation of Wnt signaling pathway altered osteocyte mineralization.

Mineralization of bone is a dynamic process, involving a complex interplay between cells, secreted macromolecules, signaling pathways, and enzymatic reactions; the dysregulation of bone mineralization may lead to serious skeletal disorders, including hypophosphatemic rickets, osteoporosis, and rheumatoid arthritis. Very few studies have reported the role of osteocytes - the most abundant bone cells in the skeletal system and the major orchestrators of bone remodeling in bone mineralization, which is owed to their nature of being deeply embedded in the mineralized bone matrix. The Wnt/ß-catenin signaling pathway is actively involved in various life processes including osteogenesis; however, the role of Wnt/ß-catenin signaling in the terminal mineralization of bone, especially in the regulation of osteocytes, is largely unknown. This research demonstrates that during the terminal mineralization process, the Wnt/ß-catenin pathway is downregulated, and when Wnt/ß-catenin signaling is activated in osteocytes, dendrite development is suppressed and the expression of dentin matrix protein 1 (DMP1) is inhibited. Aberrant activation of Wnt/ß-catenin signaling in osteocytes leads to the spontaneous deposition of extra-large mineralized nodules on the surface of collagen fibrils. The altered mineral crystal structure and decreased bonding force between minerals and the organic matrix indicate the inferior integration of minerals and collagen. In conclusion, Wnt/ß-catenin signaling plays a critical role in the terminal differentiation of osteocytes and as such, targeting Wnt/ß-catenin signaling in osteocytes may serve as a potential therapeutic approach for the management of bone-related diseases.

Prolonged overall survival following metastasectomy in stage IV melanoma.

BACKGROUND/OBJECTIVES: Current literature supports mixed conclusions regarding the outcomes of metastasectomy in Stage IV melanoma. The objective of this national study was to determine the associations of non-primary site surgery with overall survival (OS) in Stage IV melanoma. METHODS: The National Cancer Database (NCDB) was queried for all Stage IV melanoma cases diagnosed from 2004 to 2015. Cases missing treatment/staging data or undergoing palliative treatment were excluded (remaining n = 14 034). Patients were separated into 'metastasectomy' (n = 4214, 30.0%) and 'non-metastasectomy' (n = 9820, 70.0%) cohorts. Survival outcomes were analysed using Kaplan-Meier and Cox proportional hazards regressions. RESULTS: On univariate analysis, patients with Stage IV melanoma undergoing metastasectomy (median survival: 15.67 month) had greater overall survival compared with those not receiving non-primary surgery (median survival: 7.13 month; 5-year OS 13.2% vs. 5.6%, P < 0.001). M1a patients that underwent non-primary metastasectomy (median survival: 46.36 month) showed greater survival than those that did not (median survival: 15.31 month; P < 0.001). Metastasectomy was undertaken more frequently for cutaneous (M1a) metastasis compared with non-M1a metastasis (34.6% vs. 28.4%, P < 0.001). Of those receiving metastasectomy, 20.3% also received primary site resection, 33.6% radiation, 26.5% chemotherapy and 31.5% immunotherapy. Controlling for covariates on Cox proportional hazard analysis, all metastasectomy patients demonstrated longer survival [Hazard Ratio = 0.519, P < 0.001; CI 95% (0.495-0.545)] as well as when analysing solely M1a metastasectomy patients [Hazard Ratio = 0.546, P < 0.001; CI 95% (0.456-0.653)], lung (M1b) metastasectomy patients [Hazard Ratio = 0.389, P < 0.001; CI 95% (0.328-0.462)] and visceral (M1c) metastasectomy patients [Hazard Ratio = 0.474, P < 0.001; CI 95% (0.434-0.517)]. CONCLUSION: Metastasectomy for Stage IV melanoma is independently associated with improved OS in metastatic cases involving the skin, lung and visceral organs.

Incorporation of hydroxyproline in bacterial collagen from Streptococcus pyogenes.

Bacterial collagen-like proteins differ from vertebrate collagens in that they do not contain hydroxyproline, which is seen as a characteristic of the vertebrate collagens, and which provides a significant contribution to the stability of the collagen triple-helix at body temperature. Despite this difference, the bacterial collagens are stable at around body temperature through inclusion of other stabilising sequence elements. Another difference is the lack of aggregation, and certain vertebrate collagen binding domains that can be introduced into the bacterial sequence lack full function when hydroxyproline is absent. In the present study we have demonstrated that a simple method utilising co-translational incorporation during fermentation can be used to incorporate hydroxyproline into the recombinant bacterial collagen. The presence and amount of hydroxyproline incorporation was shown by amino acid analysis and by mass spectrometry. A small increase in thermal stability was observed using circular dichroism spectroscopy. STATEMENT OF SIGNIFICANCE: Recombinant bacterial collagens provide a new opportunity for biomedical materials as they are readily produced in large quantity in E. coli. Unlike animal collagens, they are stable without the need for inclusion of a secondary modification system for hydroxyproline incorporation. In animal collagens, however, introduction of hydroxyproline is essential for stability and is also important for functional molecular interactions within the mammalian extracellular matrix. The present study has shown that hydroxyproline can be readily introduced into recombinant S. pyogenes bacterial collagen through direct co-translational incorporation of this modified imino acid during expression using the codons for proline in the introduced gene construct. This hydroxylation further improves the stability of the collagen and is available to enhance any introduced molecular functions.

Residues of pesticides and metabolites in chicken kidney, liver and muscle samples from poultry farms in Dar es Salaam and Pwani, Tanzania.

The concentrations of organochlorine and organophosphorus pesticides and metabolites were investigated in chicken kidney, liver and muscle samples obtained from chickens collected from four poultry farms in Dar es Salaam and Pwani regions in Tanzania. The samples were extracted by solid dispersion using cyclohexane:ethyl acetate. The extracts were cleaned by adsorption column chromatography. The analytes were determined using gas chromatography-mass spectrometry (GC-MS). The concentrations of total DDT, total endosulfan and total HCHs in the samples ranged from 0.71 to 26, 0.3 to 7.9 and 0.02-10.4 mg/kg lipid weight (lw), respectively. The highest concentrations of aldrin, dieldrin, chlorpyrifos, fenitrothion and pirimiphos methyl were 5.5, 4.8, 9.7, 5.6 and 7.8 mg/kg lw, respectively. The highest concentrations of the contaminants were found in the kidney and liver samples. The sites in Dar es Salaam showed the highest concentrations of the compounds. Most of the concentrations were above the maximum residue limits (MRLs) indicating risks and concerns for livestock and public health.

Generalized pustular psoriasis: a review and update on treatment.

Generalized pustular psoriasis (GPP) is a subtype of pustular psoriasis characterized by painful and occasionally disfiguring cutaneous manifestations with sepsis-like systemic symptoms. Affecting any age and race, GPP can occur with other forms of psoriasis or by itself. Stimuli for flares include medications, infections and environmental triggers. The interleukin family and caspase recruitment domain family have been implicated in its pathogenesis. Other forms of pustular psoriasis include impetigo herpetiformis, palmoplantar pustular psoriasis, annular pustular psoriasis and acrodermatitis continua of Hallopeau. Treatment is not well established, but includes the use of retinoids, methotrexate, cyclosporine, corticosteroids, TNF-alpha inhibitors, topical therapy and phototherapy. The use of TNF-alpha inhibitors may result in the formation of antidrug antibodies and should be administered with methotrexate.

Where Do We Look? Assessing Gaze Patterns in Breast Reconstructive Surgery with Eye-Tracking Technology.

BACKGROUND: Aesthetics plays a large role in determining a successful outcome in plastic and reconstructive surgery. As such, understanding perceptions of favorable aesthetics is crucial for optimizing patient satisfaction. Eye-tracking technology offers an unbiased way of measuring how viewers evaluate breast reconstructions. METHODS: Twenty-nine raters with varied plastic surgery experience were shown 20 images of breast reconstruction at various stages. Breasts were divided into those with nipples and no reconstruction scars, those with nipples and reconstruction scars, and those with reconstruction scars and no nipples. Raters viewed each image for 8 seconds to evaluate aesthetic outcomes. Eye-tracking equipment and software were used to track raters' gaze and analyze the distribution of attention. RESULTS: In breasts with reconstruction scars and no nipples, viewers spent 53.9 percent of the view time examining scars, whereas viewers' attention was divided evenly in breasts with both reconstruction scars and nipples, spending 27.5 percent and 27.7 percent of view time examining the nipples and reconstruction scars, respectively. When examining complete reconstructions, viewers spent more time scanning the entire image before fixating on scars and spent less time on single-site fixation. CONCLUSIONS: Complete reconstructions, which notably include the final nipple-areola complex, appear to play an important role in restoring normal viewing parameters. In essence, completed breast reconstructions with nipple-areola complexes divert attention from extraneous surgical scars and lead viewers to assess the breasts more holistically. Eye-tracking technology provides a powerful link between objective gaze and viewer attention that may potentially be used to predict subjective aesthetic preferences.

GYY4137, a Hydrogen Sulfide Donor Modulates miR194-Dependent Collagen Realignment in Diabetic Kidney.

The relationship between hydrogen sulfide (H2S), microRNAs (miRs), matrix metalloproteinases (MMPs) and poly-ADP-ribose-polymerase-1 (PARP-1) in diabetic kidney remodeling remains mostly obscured. We aimed at investigating whether alteration of miR-194-dependent MMPs and PARP-1 causes renal fibrosis in diabetes kidney, and whether H2S ameliorates fibrosis. Wild type, diabetic Akita mice as well as mouse glomerular endothelial cells (MGECs) were used as experimental models, and GYY4137 as H2S donor. In diabetic mice, plasma H2S levels were decreased while ROS and expression of its modulator (ROMO1) were increased. In addition, alteration of MMPs-9, -13 and -14 expression, PARP-1, HIF1α, and increased collagen biosynthesis as well as collagen cross-linking protein, P4HA1 and PLOD2 were observed along with diminished vascular density in diabetic kidney. These changes were ameliorated by GYY4137. Further, downregulated miRNA-194 was normalized by GYY4137 in diabetic kidney. Similar results were obtained in in vitro condition. Interestingly, miR-194 mimic also diminished ROS production, and normalized ROMO1, MMPs-9, -13 and -14, and PARP-1 along with collagen biosynthesis and cross-linking protein in HG condition. We conclude that decrease H2S diminishes miR-194, induces collagen deposition and realignment leading to fibrosis and renovascular constriction in diabetes. GYY4137 mitigates renal fibrosis in diabetes through miR-194-dependent pathway.

Induction of Plac8 promotes pro-survival function of autophagy in cadmium-induced prostate carcinogenesis.

Chronic exposure to cadmium is known to be a risk factor for human prostate cancer. Despite over-whelming evidence of cadmium causing carcinogenicity in humans, the specific underlying molecular mechanisms that govern metal-induced cellular transformation remain unclear. Acute exposure (up to 72 h) to cadmium induces apoptosis in normal prostate epithelial cells (RWPE-1), while chronic exposure (>1 year) transforms these cells to a malignant phenotype (cadmium-transformed prostate epithelial cells; CTPE). Increased expression of autophagy-regulated genes; Plac8, LC3B and Lamp-1; in CTPE cells was associated with cadmium-induced transformation. Increased expression of Plac8, a regulator of autophagosome/autolysosome fusion, facilitates the pro-survival function of autophagy and upregulation of pAKT(ser473) and NF-κß, to allow CTPE to proliferate. Likewise, inhibition of Plac8 suppresses CTPE cell growth. Additionally, overexpression of Plac8 in RWPE-1 cells induces resistance to cadmium toxicity. Pharmacological inhibitors and an inducer of autophagy failed to affect Plac8 expression and CTPE cell viability, suggesting a unique role for Plac8 in cadmium-induced prostate epithelial cell transformation. These results support a role for Plac8 as an essential component in the cadmium-induced transformation of normal prostate epithelial cells to a cancerous state.

Stabilisation of Collagen Sponges by Glutaraldehyde Vapour Crosslinking.

Glutaraldehyde is a well-recognised reagent for crosslinking and stabilising collagens and other protein-based materials, including gelatine. In some cases, however, the use of solutions can disrupt the structure of the material, for example, by causing rapid dispersion or distortions from surface interactions. An alternative approach that has been explored in a number of individual cases is the use of glutaraldehyde vapour. In this study, the effectiveness of a range of different glutaraldehyde concentrations in the reservoir providing vapour, from 5% to 25% (w/v), has been explored at incubation times from 5 h to 48 h at room temperature. These data show the effectiveness of the glutaraldehyde vapour approach for crosslinking collagen and show that materials with defined, intermediate stability could be obtained, for example, to control resorption rates in vivo.

Validation of a Cognitive Task Simulation and Rehearsal Tool for Open Carpal Tunnel Release.

BACKGROUND: Carpal tunnel release is one of the most common surgical procedures performed by hand surgeons. The authors created a surgical simulation of open carpal tunnel release utilizing a mobile and rehearsal platform app. This study was performed in order to validate the simulator as an effective training platform for carpal tunnel release. METHODS: The simulator was evaluated using a number of metrics: construct validity (the ability to identify variability in skill levels), face validity (the perceived ability of the simulator to teach the intended material), content validity (that the simulator was an accurate representation of the intended operation), and acceptability validity (willingness of the desired user group to adopt this method of training). Novices and experts were recruited. Each group was tested, and all participants were assigned an objective score, which served as construct validation. A Likert-scale questionnaire was administered to gauge face, content, and acceptability validity. RESULTS: Twenty novices and 10 experts were recruited for this study. The objective performance scores from the expert group were significantly higher than those of the novice group, with surgeons scoring a median of 74% and medical students scoring a median of 45%. The questionnaire responses indicated face, content, and acceptability validation. CONCLUSIONS: This mobile-based surgical simulation platform provides step-by-step instruction for a variety of surgical procedures. The findings of this study help to demonstrate its utility as a learning tool, as we confirmed construct, face, content, and acceptability validity for carpal tunnel release. This easy-to-use educational tool may help bring surgical education to a new-and highly mobile-level.

Determination of Levels of Organochlorine, Organophosphorus, and Pyrethroid Pesticide Residues in Vegetables from Markets in Dar es Salaam by GC-MS.

This study investigated the levels of pesticides and metabolites in vegetables from major markets in Dar es Salaam city, Tanzania. Samples of fresh cabbage, spinach, and onions from the markets were analysed for pesticide residues. Extraction was performed using acetone followed by dichloromethane : cyclohexane mixture and the extracts were cleaned up using Florisil. The compounds were determined by gas chromatography-mass spectrometry (GC-MS). Pesticides and metabolites were detected in 72.2% of the samples. The detected pesticide residues and their highest mean concentrations were p,p'-DDT 4.00 × 10-3 mg/kg, p,p'-DDD 6.40 × 10-1 mg/kg, o,p'-DDD 1.00 × 10-2 mg/kg, α-endosulfan 6.00 × 10-1 mg/kg, ß-endosulfan 2.10 × 10-1 mg/kg, chlorpyrifos 3.00 mg/kg, and cypermethrin 4.00 × 10-2 mg/kg. The most frequently detected compounds were p,p'-DDD and chlorpyrifos. The order of contamination was spinach > cabbage > onions. Generally, there were no significant variations in concentrations of pesticide residues among samples and sampling sites, which indicated similarities in contamination patterns. The concentrations of contaminants were above the maximum residue limits (MRLs) in 33.3-50% of the samples. The findings indicated risks and concerns for public health.

Bioengineered Collagens.

There is a great deal of interest in obtaining recombinant collagen as an alternative source of material for biomedical applications and as an approach for obtaining basic structural and biological information. However, application of recombinant technology to collagen presents challenges, most notably the need for post-translational hydroxylation of prolines for triple-helix stability. Full length recombinant human collagens have been successfully expressed in cell lines, yeast, and several plant systems, while collagen fragments have been expressed in E. coli. In addition, bacterial collagen-like proteins can be expressed in high yields in E. coli and easily manipulated to incorporate biologically active sequences from human collagens. These expression systems allow manipulation of biologically active sequences within collagen, which has furthered our understanding of the relationships between collagen sequences, structure and function. Here, recombinant studies on collagen interactions with cell receptors, extracellular matrix proteins, and matrix metalloproteinases are reviewed, and discussed in terms of their potential biomaterial and biomedical applications.