Thermal injury of skin and subcutaneous tissues: A review of experimental approaches and numerical models

Revalidating the prognostic relevance of the Abbreviated Burn Severity Index (ABSI): A twenty-year experience examining the performance of the ABSI score in consideration of progression and advantages of burn treatments from a single center in Vienna

BACKGROUND

The Abbreviated Burn Severity Index (ABSI) is a five-variable scale to help evaluate burn severity upon initial assessment. As other studies have been conducted with comparatively small patient populations, the purpose of this study is to revalidate the prognostic relevance of the ABSI in our selected population (N = 1193) 4 decades after its introduction, considering the progress in the treatment of severe burn injuries over the past decades. In addition, we evaluate whether comorbidities influence the survival probability of severely burned patients.

METHODS

This retrospective study presents data from the Center for Severely Burned Patients of the General Hospital in Vienna. We included 1193 patients for over 20 years. Regression models were used to describe the prognostic accuracy of the ABSI.

RESULTS

The ABSI can still be used as a prognostic factor for the probability of survival of severely burned patients. The odds of passing increases by a factor of 2.059 for each unit increase in the ABSI with an area under the curve value of 0.909. Over time, the likelihood of survival increased. The existence of chronic kidney disease negatively impacts the survival probability of severely burned patients.

CONCLUSION

The ABSI can still be used to provide accurate information about the chances of survival of severely burned patients; however, further exploration of the impact of chronic kidney disease on the survival probability and adding variables to the ABSI scale should be considered. The probability of survival has increased over the last 20 years.

Biomineral-Based Composite Materials in Regenerative Medicine

Regenerative medicine aims to address substantial defects by amplifying the body's natural regenerative abilities and preserving the health of tissues and organs. To achieve these goals, materials that can provide the spatial and biological support for cell proliferation and differentiation, as well as the micro-environment essential for the intended tissue, are needed. Scaffolds such as polymers and metallic materials provide three-dimensional structures for cells to attach to and grow in defects. These materials have limitations in terms of mechanical properties or biocompatibility. In contrast, biominerals are formed by living organisms through biomineralization, which also includes minerals created by replicating this process. Incorporating biominerals into conventional materials allows for enhanced strength, durability, and biocompatibility. Specifically, biominerals can improve the bond between the implant and tissue by mimicking the micro-environment. This enhances cell differentiation and tissue regeneration. Furthermore, biomineral composites have wound healing and antimicrobial properties, which can aid in wound repair. Additionally, biominerals can be engineered as drug carriers, which can efficiently deliver drugs to their intended targets, minimizing side effects and increasing therapeutic efficacy. This article examines the role of biominerals and their composite materials in regenerative medicine applications and discusses their properties, synthesis methods, and potential uses.

Tougher Bioadhesives through Dual Stimulation Strategies

Carbene-based bioadhesives have favourable attributes for tissue adhesion, including non-specific bonding to wet and dry tissues, but suffer from relatively weak fracture strength after photocuring. Light irradiation of carbene-precursor (diazirine) also creates inert side products that are absent under thermal activation. Herein, a dual activation method combines light irradiation at elevated temperatures for the evaluation of diazirine depletion and effects on cohesive properties. A customized photo/thermal-rheometer evaluates viscoelastic properties, correlated to the kinetics of carbene:diazoalkane ratios via 19F NMR). The latter exploits the sensitive -CF3 functional group to determine joule-based light/temperature kinetics on trifluoroaryl diazirine consumption. The combination of heat and photoactivation produced bioadhesives that are 3× tougher compared to control. Dual thermal/light irradiation may be a strategy to improve viscoelastic dissipation and toughness of photo-activated adhesive resins.

The transdifferentiation of human dedifferentiated fat cells into fibroblasts: An in vitro experimental pilot study

BACKGROUND

Skin grafting is a common method of treating damaged skin; however, surgical complications may arise in patients with poor health. Currently, no effective conservative treatment is available for extensive skin loss. Mature adipocytes, which constitute a substantial portion of adipose tissue, have recently emerged as a potential source of stemness. When de-lipidated, these cells exhibit fibroblast-like characteristics and the ability to redifferentiate, offering homogeneity and research utility as "dedifferentiated fat cells."

METHODS AND RESULTS

We conducted an in vitro study to induce fibroblast-like traits in the adipose tissue by transdifferentiating mature adipocytes for skin regeneration. Human subcutaneous fat tissues were isolated and purified from mature adipocytes that underwent a transformation process over 14 days of cultivation. Microscopic analysis revealed lipid degradation over time, ultimately transforming cells into fibroblast-like forms. Flow cytometry was used to verify their characteristics, highlighting markers such as CD90 and CD105 (mesenchymal stem cell markers) and CD56 and CD106 (for detecting fibroblast characteristics). Administering dedifferentiated fat cells with transforming growth factor-β at the identified optimal differentiation concentration of 5 ng/mL for a span of 14 days led to heightened expression of alpha smooth muscle actin and fibronectin, as evidenced by RNA and protein analysis. Meanwhile, functional validation through cell sorting demonstrated limited fibroblast marker expression in both treated and untreated cells after transdifferentiation by transforming growth factor-β.

CONCLUSION

Although challenges remain in achieving more effective transformation and definitive fibroblast differentiation, our trial could pave the way for a novel skin regeneration treatment strategy.

Reverse Iontophoresis: Noninvasive Assessment of Topical Drug Bioavailability

Assessing drug disposition in the skin after the application of a topical formulation is difficult. It is hypothesized that reverse iontophoresis (RI), which can extract charged/polar molecules for monitoring purposes, may provide a noninvasive approach for the assessment of local drug bioavailability. The passive and RI extraction of salicylic acid (SA) and nicotine (NIC) from porcine skin in vitro was assessed after a simple solution of the former and a transdermal patch of the latter had been applied for 24 and 8 h, respectively. Immediately after this "passive skin loading", the amount of drug in the stratum corneum (SC) and "viable" tissue (VT) was measured either (a) after tape-stripping and subsequent solvent extraction of both skin layers or (b) following RI extraction over 4 h. Parallel experiments were then performed in vivo in healthy volunteers; in this case, the VT was not sampled and the skin loading period for NIC was only 4 h. RI extraction of both drugs was significantly higher (in vitro and in vivo) than that achieved passively, and the cumulative RI extraction profiles as a function of time were mathematically analyzed using a straightforward compartmental model. Best-fit estimates of drug amounts in the SC and VT (ASC,0 and AVT,0, respectively) at the end of "loading" and two first-order rate constants describing transfer between the model compartments were then determined. The in vitro predictions of ASC,0 and AVT,0 were in excellent agreement with the experimental results, as was the value of the former in vivo. The rate constants derived from the in vitro and in vivo results were also similar. In summary, the results provide proof-of-concept that the RI method has the potential to noninvasively assess relevant metrics of drug bioavailability in the skin.

Non-invasive medical imaging technology for the diagnosis of burn depth

Currently, the clinical diagnosis of burn depth primarily relies on physicians' judgements based on patients' symptoms and physical signs, particularly the morphological characteristics of the wound. This method highly depends on individual doctors' clinical experience, proving challenging for less experienced or primary care physicians, with results often varying from one practitioner to another. Therefore, scholars have been exploring an objective and quantitative auxiliary examination technique to enhance the accuracy and consistency of burn depth diagnosis. Non-invasive medical imaging technology, with its significant advantages in examining tissue surface morphology, blood flow in deep and changes in structure and composition, has become a hot topic in burn diagnostic technology research in recent years. This paper reviews various non-invasive medical imaging technologies that have shown potential in burn depth diagnosis. These technologies are summarized and synthesized in terms of imaging principles, current research status, advantages and limitations, aiming to provide a reference for clinical application or research for burn specialists.

Thermal Imaging as a Method to Indirectly Assess Peripheral Vascular Integrity and Tissue Viability in Veterinary Medicine: Animal Models and Clinical Applications

Infrared thermography (IRT) is a technique that indirectly assesses peripheral blood circulation and its resulting amount of radiated heat. Due to these properties, thermal imaging is currently applied in human medicine to noninvasively evaluate peripheral vascular disorders such as thrombosis, thromboembolisms, and other ischemic processes. Moreover, tissular damage (e.g., burn injuries) also causes microvasculature compromise. Therefore, thermography can be applied to determine the degree of damage according to the viability of tissues and blood vessels, and it can also be used as a technique to monitor skin transplant procedures such as grafting and free flaps. The present review aims to summarize and analyze the application of IRT in veterinary medicine as a method to indirectly assess peripheral vascular integrity and its relation to the amount of radiated heat and as a diagnostic technique for tissue viability, degree of damage, and wound care.

Present and future of pure shift NMR in metabolomics

NMR is one of the most powerful techniques for the analysis of biological samples in the field of metabolomics. However, the high complexity of fluids, tissues, or other biological materials taken from living organisms is still a challenge for state-of-the-art pulse sequences, thereby limiting the detection, the identification, and the quantification of metabolites. In this context, the resolution enhancement provided by broadband homonuclear decoupling methods, which allows for simplifying 1 H multiplet patterns into singlets, has placed this so-called pure shift technique as a promising approach to perform metabolic profiling with unparalleled level of detail. In recent years, the many advances achieved in the design of pure shift experiments has paved the way to the analysis of a wide range of biological samples with ultra-high resolution. This review leads the reader from the early days of the main pure shift methods that have been successfully developed over the last decades to address complex samples, to the most recent and promising applications of pure shift NMR to the field of NMR-based metabolomics.

Cutaneous and Respiratory Lesions in Bushfire-Affected Koalas

In the wake of increasingly frequent bushfires emerging as a threat to wildlife worldwide, koalas have notably been the most rescued species in Australia. However, our understanding of burns and their severity in koalas is limited; hence, this study investigated the histopathological features and depth of burns in koala skin, as well as the presence of smoke-induced respiratory tract damage. In four bushfire-affected koalas that had been euthanised on welfare grounds, skin burns in various body regions were scored based on clinical appearance as superficial, partial thickness, or full thickness. Histological sections of affected regions of skin were assessed as Grades I-IV and showed that furred regions on the ear margins and dorsum were histologically more severe, at Grade III, compared with the clinical score. There was a similar finding for footpad burns, which were the most common body region affected. In the respiratory tract, pulmonary oedema and congestion were evident in all koalas. Overall, the results highlight that cutaneous burn lesions on furred and palmar/plantar surfaces can have higher severity based on the burn depth than is clinically apparent. Therefore, there is a need to consider this when developing treatment plans and establishing prognosis for burnt koalas at triage, as well as that a high likelihood of pulmonary oedema exists.

Ultrasonography for Skin and Soft Tissue Infections, Noninfectious Cysts, Foreign Bodies, and Burns in the Critical Care Setting

There are multiple opportunities for the use of ultrasonography in the diagnosis of skin and soft tissue differentials. Ultrasonography is inexpensive, easily reproducible, and able to provide real-time data in situations where condition changes and progression are common. Not only does bedside ultrasonography provide the clinician an in-depth look beyond epidermal structures into body cavities, it remains a safe, nonionizing radiating, effective, cost-efficient, reliable, and accessible tool for the emergency management of life- and limb-threatening integumentary infections. Unnecessary invasive procedures are minimized, providing improved patient outcomes. Integumentary abnormalities secondary to trauma, surgery, and hospitalization are common among critical care patients. This article provides a brief overview and evidence-based recommendations for the use of ultrasonography in the critical care setting for integumentary system conditions, including common skin and soft tissue differentials, foreign bodies, and burn depth assessment.

Near-Infrared Remotely Controllable Shape Memory Biodegradable Occluder Based on Poly(l-lactide-co-ε-caprolactone)/Gold Nanorod Composite

Biodegradable occluders, which can efficiently eliminate the complications caused by permanent foreign implants, are considered to be the next-generation devices for the interventional treatment of congenital heart disease. However, the controllability of the deployment process of degradable occluders remains a challenge. In this work, a near-infrared (NIR) remotely controllable biodegradable occluder is explored by integrating poly(l-lactide-co-ε-caprolactone) (PLCL) with poly(ethylene glycol)-modified gold nanorods (GNR/PEG). The caprolactone structural units can effectively increase the toughness of poly(l-lactide) and reduce the shape-memory transition temperature of the occluder to a more tissue-friendly temperature. Gold nanorods endow the PLCL-GNR/PEG composite with an excellent photothermal effect. The obtained occluder can be easily loaded into a catheter for transport and spatiotemporally expanded under irradiation with near-infrared light to block the defect site. Both in vitro and in vivo biological experiments showed that PLCL-GNR/PEG composites have good biocompatibility, and the PEGylated gold nanorods could improve the hemocompatibility of the composites to a certain extent by enhancing their hydrophilicity. As a thermoplastic shape-memory polymer, PLCL-GNR/PEG can be easily processed into various forms and structures for different patients and lesions. Therefore, PLCL-GNR/PEG has the potential to be considered as a competitive biodegradable material not only for occluders but also for other biodegradable implants.

Damage and Fracture Mechanics of Porcine Subcutaneous Tissue Under Tensile Loading

Subcutaneous injection, which is a preferred delivery method for many drugs, causes deformation, damage, and fracture of the subcutaneous tissue. Yet, experimental data and constitutive modeling of these dissipation mechanisms in subcutaneous tissue remain limited. Here we show that subcutaneous tissue from the belly and breast anatomical regions in the swine show nonlinear stress-strain response with the characteristic J-shaped behavior of collagenous tissue. Additionally, subcutaneous tissue experiences damage, defined as a decrease in the strain energy capacity, as a function of the previously experienced maximum deformation. The elastic and damage response of the tissue are accurately described by a microstructure-driven constitutive model that relies on the convolution of a neo-Hookean material of individual fibers with a fiber orientation distribution and a fiber recruitment distribution. The model fit revealed that subcutaneous tissue can be treated as initially isotropic, and that changes in the fiber recruitment distribution with loading are enough to explain the dissipation of energy due to damage. When tested until failure, subcutaneous tissue that has undergone damage fails at the same peak stress as virgin samples, but at a much larger stretch, overall increasing the tissue toughness. Together with a finite element implementation, these data and constitutive model may enable improved drug delivery strategies and other applications for which subcutaneous tissue biomechanics are relevant.

mTOR pathway - a potential therapeutic target in stroke

Stroke is ranked as the second leading cause of death worldwide and a major cause of long-term disability. A potential therapeutic target that could offer favorable outcomes in stroke is the mammalian target of rapamycin (mTOR) pathway. mTOR is a serine/threonine kinase that composes two protein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), and is regulated by other proteins such as the tuberous sclerosis complex. Through a significant number of signaling pathways, the mTOR pathway can modulate the processes of post-ischemic inflammation and autophagy, both of which play an integral part in the pathophysiological cascade of stroke. Promoting or inhibiting such processes under ischemic conditions can lead to apoptosis or instead sustained viability of neurons. The purpose of this review is to examine the pathophysiological role of mTOR in acute ischemic stroke, while highlighting promising neuroprotective agents such as hamartin for therapeutic modulation of this pathway. The therapeutic potential of mTOR is also discussed, with emphasis on implicated molecules and pathway steps that warrant further elucidation in order for their neuroprotective properties to be efficiently tested in future clinical trials.

The quantitative investigation of spark plasma on skin parameters with skin elasticity, thickness, density, and biometric characteristics

Cold atmospheric plasma has been developed and utilized as a novel technique for skin rejuvenation because of its various effects on cells and living things. This study investigated the accuracy of this claim and any possible side effects of using spark plasma to rejuvenate skin. The present work is the first quantitative investigation using animal models. 12 Wistar rats were divided into two groups for this investigation. To compare the skin's natural process with the treated skin, the first group underwent a single session of plasma therapy, while the second group served as the control group. The back of the necks of the samples was shaved for 20 cm. Before beginning treatment, the MPA9 multifunctional skin tester was used to determine the melanin index, erythema index, and transepidermal water loss (TEWL). The skin's thickness and density were assessed using sonography, and its elasticity index was calculated using a Cutometer. The samples were exposed to plasma radiation in the designated area (in a triangular pattern). The abovementioned signs were examined immediately after the following therapy and at the weekly appointment 2-4 weeks later. Optical spectroscopy was also used to demonstrate the presence of active species. In this study, we found that a plasma spark therapy session significantly boosts skin elasticity, and the ultrasound results revealed a significantly increased skin thickness and density. The plasma increased the amount of skin surface evaporation, erythema, and melanin immediately following the treatment. However, 4 weeks later, it recovered to its former state and did not differ significantly from before the therapy.

The Perspective of Psychological Action Mechanism of Mindfulness Meditation: Mindfulness Meditation Blurs the Transparent Boundary Between the Unconscious and the Conscious Mind

Based on the author's clinical experience, the aim of this paper is to conceptually analyse the theory of psychological functioning and action mechanisms in the way mindfulness meditation works. Meditation is a method of revealing unconsciousness. It works in a similar way to the inhibitory and excitatory mechanisms of neurones. Block pathogenic thoughts and emotions that reach the unconscious to the conscious mind. The long-term implementation of mediation may be more effective than the short-term and interrupted implementation.

Fine-Tuning the Endcap Chemistry of Acrylated Poly(Ethylene Glycol)-Based Hydrogels for Efficient Burn Wound Exudate Management

Most commercial dressings with moderate to high exudate uptake capacities are mechanically weaker and/or require a secondary dressing. The current research article focuses on the development of hydrogel-based wound dressings combining mechanical strength with high exudate absorption capacities using acrylate-endcapped urethane-based precursors (AUPs). AUPs with varying poly(ethylene glycol) backbone molar masses (10 and 20 kg mol^-1 ) and endcap chemistries are successfully synthesized in toluene, subsequently processed into UV-cured hydrogel sheets and are benchmarked against several commercial wound dressings (Hydrosorb, Kaltostat, and Mepilex Ag). The AUP materials show high gel fractions (>90%) together with strong swelling degrees in water, phosphate buffered saline and simulated wound fluid (12.7-19.6 g g^-1 ), as well as tunable mechanical properties (e.g., Young's modulus: 0.026-0.061 MPa). The AUPs have significantly (p < 0.05) higher swelling degrees than the tested commercial dressings, while also being mechanically resistant. The elasticity of the synthesized materials leads to an increased resistance against fatigue. The di- and hexa-acrylated AUPs show excellent in vitro biocompatibility against human foreskin fibroblasts, as evidenced by indirect MTS assays and live/dead cell assays. In conclusion, the processed AUP materials demonstrate high potential for wound healing application and can even compete with commercially available dressings.

Histopathological findings in a pilot study of dairy calves disbudded with hot cauterization or caustic paste

We describe the histological tissue damage and compare the healing process in 16 dairy calves disbudded at a mean age of 6 days by cauterization or alkaline caustic paste application. Biopsies were taken 2 days (T2) and 2 weeks (T14) after disbudding from sedated calves treated with local anaesthetic and non-steroidal anti-inflammatory drugs. At T2, the cauterized horn buds generally had eosinophilic coagulative necrosis of the epidermis and superficial dermis, bordered basally by a neutrophilic demarcation zone. Lateral to the direct heat contact area, dermal blood vessels were thrombosed, with wall damage and perivascular neutrophils. In the caustic paste-treated horn buds, the epidermis and dermis had diffuse full-thickness liquefactive necrosis directly under the paste contact area. The necrosis spread laterally in the dermis beyond the area of paste contact and was bordered by a neutrophilic infiltrate. At T14, the cauterized horn buds had epidermal to superficial dermal ulceration and crusting, dermal neutrophilic infiltration and granulation tissue formation. In contrast, most of the caustic paste-treated horn buds consisted of a superficial dermal crust or predominantly necrotic tissue fragments. The remaining viable areas had histiocytic inflammation with peripheral neutrophils and early granulation tissue formation. Caustic paste disbudding caused poorly demarcated lesions that were more severe and extensive and took longer to heal than those due to cautery. Cauterization induced a more intense acute reaction adjacent to the primary lesion compared with caustic paste.

Nucleotide detection mechanism and comparison based on low-dimensional materials: A review

The recent pandemic has led to the fabrication of new nucleic acid sensors that can detect infinitesimal limits immediately and effectively. Therefore, various techniques have been demonstrated using low-dimensional materials that exhibit ultrahigh detection and accuracy. Numerous detection approaches have been reported, and new methods for impulse sensing are being explored. All ongoing research converges at one unique point, that is, an impetus: the enhanced limit of detection of sensors. There are several reviews on the detection of viruses and other proteins related to disease control point of care; however, to the best of our knowledge, none summarizes the various nucleotide sensors and describes their limits of detection and mechanisms. To understand the far-reaching impact of this discipline, we briefly discussed conventional and nanomaterial-based sensors, and then proposed the feature prospects of these devices. Two types of sensing mechanisms were further divided into their sub-branches: polymerase chain reaction and photospectrometric-based sensors. The nanomaterial-based sensor was further subdivided into optical and electrical sensors. The optical sensors included fluorescence (FL), surface plasmon resonance (SPR), colorimetric, and surface-enhanced Raman scattering (SERS), while electrical sensors included electrochemical luminescence (ECL), microfluidic chip, and field-effect transistor (FET). A synopsis of sensing materials, mechanisms, detection limits, and ranges has been provided. The sensing mechanism and materials used were discussed for each category in terms of length, collectively forming a fusing platform to highlight the ultrahigh detection technique of nucleotide sensors. We discussed potential trends in improving the fabrication of nucleotide nanosensors based on low-dimensional materials. In this area, particular aspects, including sensitivity, detection mechanism, stability, and challenges, were addressed. The optimization of the sensing performance and selection of the best sensor were concluded. Recent trends in the atomic-scale simulation of the development of Deoxyribonucleic acid (DNA) sensors using 2D materials were highlighted. A critical overview of the challenges and opportunities of deoxyribonucleic acid sensors was explored, and progress made in deoxyribonucleic acid detection over the past decade with a family of deoxyribonucleic acid sensors was described. Areas in which further research is needed were included in the future scope.

The Protective Performance of Process Operators' Protective Clothing and Exposure Limits under Low Thermal Radiation Conditions

During the early stage of a fire, a process operator often acts as the first responder and may be exposed to high heat radiation levels. The present limit values of long- (>15 min) and short-term exposure (<5 min), 1.0 and 1.5 kW/m2, respectively, have been set using physiological models and manikin measurements. Since human validation is essentially lacking, this study investigated whether operators’ protective clothing offers sufficient protection during a short-term deployment. Twelve professional firefighters were exposed to three radiation levels (1.5, 2.0, and 2.5 kW/m2) when wearing certified protective clothing in front of a heat radiation panel in a climatic chamber (20 °C; 50% RH). The participants wore only briefs (male) or panties and a bra (female) and a T-shirt under the operators’ clothing. Skin temperatures were continuously measured at the chest, belly, forearm, thigh, and knee. The test persons had to stop if any skin temperature reached 43 °C, at their own request, or when 5 min of exposure was reached. The experiments showed that people in operators’ clothing can be safely exposed for 5 min to 1.5 kW/m2, up to 3 min to 2.0 kW/m2, and exposure to 2.5 kW/m2 or above must be avoided unless the clothing can maintain an air gap.

A longitudinal-torsional mode ultrasonic needle for deep penetration into bone

This work presents a longitudinal-torsional (L-T) composite mode ultrasonic needle device for deep bone penetration. The L-T needle is a geometrically modified version of an L-mode needle whose efficacy as a prototype ultrasonic bone biopsy device has been previously demonstrated by the authors. Finite element analysis (FEA) aided in the design of the L-T needle, with the aim of maximising the achievable torsional displacement while matching the longitudinal displacement achieved by the L-mode needle. Experimental modal analysis (EMA) of the fabricated ultrasonic device was used to identify the modal parameters and validate the FEA model. Harmonic analysis then provided an insight into how the inherent nonlinearities of the high-power transducer are affected by incorporating the geometrical features that degenerate the L mode into an L-T mode. High power characterisation shows that the longitudinal displacement amplitude of the L-T mode needle is larger than that of the L-mode needle. Comparative penetration tests in fresh Wistar rat skull were evaluated by investigating cell death and cell survival. The region of statistically significant cell death was small for both devices, with the combined axial and shear motion of the L-T device causing increased osteocyte necrosis within this region. Nevertheless, the results suggest a promising environment for post-operative healing. It is shown how this technology offers a potential technique for a surgical approach to the petrous apex, an application that requires a deep penetration into bone.

Comparative Effects of Recove® and Nitrofurazone 0.2% on the Treatment of First and Second-Degree Burns: a Double-Blind Randomized Clinical Trial

Background

Burns are among the major health challenges of all societies and more than any other trauma incur physical, mental, social, and economic burdens on the patient and society. This study was conducted to assess whether Recove^® burn ointment is capable of alleviating the pain, preventing the formation of new blisters and controlling the microbial contamination of the wound.

Methods

We, therefore, compared its efficacy to ​​nitrofurazone 0.2% cream. This randomized clinical trial was conducted on individuals who had two burn injuries in their body at the same time in the Motahari Burn Hospital, Tehran Province, from June to October 2016. Sampling was carried out with a non-random method using available samples. The intervention in experimental and control groups was Recove^® and nitrofurazone, respectively. The effect of interventions on pain relief, the formation of new blisters and prevention of infection at the burn wound were evaluated. In our double-blind study, blindness was applied to the patients and the person evaluating the outcomes.

Results

Both Recove^® and nitrofurazone interventions significantly alleviated pain (P < 0.01), but Recove ^®showed more effectiveness (P=0.01). Similarly, in terms of new blister formation, the experimental group receiving Recove^® showed less new blister formation over 24 hours after treatment compared to nitrofurazone group (P=0.03) and with respect to antimicrobial activity, there was no significant difference between Recove^® and nitrofurazone (P=0.12).

Conclusion

Recove^® was effective on pain reduction, prevention of new blisters formation as well as infection. Therefore, it seems that Recove^® could be considered as a new and efficient treatment for burn.

Burn depth assessment using hyperspectral imaging in a prospective single center study

BACKGROUND

The assessment of thermal burn depth remains challenging. Over the last decades, several optical systems were developed to determine burn depth. So far, only laser doppler imaging (LDI) has been shown to be reliable while others such as infrared thermography or spectrophotometric intracutaneous analysis have been less accurate. The aim of our study is to evaluate hyperspectral imaging (HSI) as a new optical device.

METHODS

Patients suffering thermal trauma treated in a burn unit in Germany between November 2019 and September 2020 were included. Inclusion criteria were age ≥18 years, 2^nd or 3^rd degree thermal burns, written informed consent and presentation within 24 h after injury. Clinical assessment and hyperspectral imaging were performed 24, 48 and 72 h after the injury. Patients in whom secondary wound closure was complete within 21 days (group A) were compared to patients in whom secondary wound closure took more than 21 days or where skin grafting was indicated (group B). Demographic data and the primary parameters generated by HSI were documented. A Mann Whitney-U test was performed to compare the groups. A p-value below 0.05 was considered to be statistically significant. The data generated using HSI were combined to create the HSI burn index (BI). Using a logistic regression and receiver operating characteristics curve (ROC) sensitivity and specificity of the BI were calculated. The trial was officially registered on DRKS (registration number: DRKS00022843).

RESULTS

Overall, 59 patients with burn wounds were eligible for inclusion. Ten patients were excluded because of a poor data quality. Group A comprised 36 patients with a mean age of 41.5 years and a mean burnt body surface area of 2.7%. In comparison, 13 patients were allocated to group B because of the need for a skin graft (n = 10) or protracted secondary wound closure lasting more than 21 days. The mean age of these patients was 46.8 years. They had a mean affected body surface area of 4.0%. 24, 48, and 72 h after trauma the BI was 1.0 ± 0.28, 1.2 ± 0.29 and 1.55 ± 0.27 in group A and 0.78 ± 0.14, 1.05 ± 0.23 and 1.23 ± 0.27 in group B. At every time point significant differences were demonstrated between the groups. At 24 h, ROC analysis demonstrated BI threshold of 0.95 (sensitivity 0.61/specificity 1.0), on the second day of 1.17 (sensitivity 0.51/specificity 0.81) and on the third day of 1.27 (sensitivity 0.92/specificity 0.71).

CONCLUSION

Changes in microcirculation within the first 72 h after thermal trauma were reflected by an increasing BI in both groups. After 72 h, the BI is able to predict the need for a skin graft with a sensitivity of 92% and a specificity of 71%.

Commercial wound dressings for the treatment of exuding wounds: an in-depth physico-chemical comparative study

Background

Nowadays, a wide range of wound dressings is already commercially available. The selection of the dressing is of paramount importance as inappropriate wound management and dressing selection can delay the wound healing process. Not only can this be distressing for the patient, but it can also contribute to complications such as maceration and subsequent infection. Many researchers are targeting the design of dressings with superior properties over existing commercial dressings. However, reported results in the state-of-the-art are rarely benchmarked against commercial dressings. The aim of this study was to determine several characteristics of a large variety of the most frequently used commercial wound dressings, providing an overview for both practitioners and researchers.

Methods

For this comparative study, 11 frequently used commercial wound dressings were selected, representing the different types. The morphology was studied using scanning electron microscopy. The dressings were characterized in terms of swelling capacity (water, phosphate buffered saline and simulated wound fluid), moisture vapour transmission rate (MVTR) and moisture uptake capacity (via dynamic vapour sorption) as well as mechanical properties using tensile testing and texturometry.

Results

The selected dressings showed distinctive morphological differences (fibrous, porous and/or gel) which was reflected in the different properties. Indeed, the swelling capacities ranged between 1.5 and 23.2 g/g (water), 2.1 and 17.6 g/g (phosphate buffered saline) or 2.9 and 20.8 g/g (simulated wound fluid). The swelling capacity of the dressings in water increased even further upon freeze-drying, due to the formation of pores. The MVTR values varied between 40 and 930 g/m²/24 h. The maximal moisture uptake capacity varied between 5.8% and 105.7% at 95% relative humidity. Some commercial dressings exhibited a superior mechanical strength, due to either being hydrophobic or multi-layered.

Conclusions

The present work not only offers insight into a valuable toolbox of suitable wound dressing characterization techniques, but also provides an extensive landscaping of commercial dressings along with their physico-chemical properties, obtained through reproducible experimental protocols. Furthermore, it ensures appropriate benchmark values for commercial dressings in all forthcoming studies and could aid researchers with the development of novel modern wound dressings. The tested dressings either exhibited a high strength or a high swelling capacity, suggesting that there is still a strong potential in the wound dressings market for dressings that possess both.

Cutaneous steam burns and steam inhalation injuries: a literature review and a case presentation

Abstract

Scald is one type of burn that s often mentioned alone and occurs mostly in the paediatric population. Inhaled steam is mostly cooled off in the airways, why thermal damage is rarely seen. A sudden exposure to hot steam/inhalation can cause a thermal inhalation injury. A scoping review was performed, with the aim to summarize all published papers in English, about steam-related injuries. The search was conducted using the PubMed® and Cochrane libraries on 19th of May 2021, without a set time period. Out of a total of 1186 identified records, 31 were chosen for review. Burns related to the contact with steam are generally rare and can be both minor and severe. The more severe cases related to steam exposure are mostly workplace accidents and the minor injuries reported in the literature are often related to steam inhalation therapy, especially in the paediatric population. This review describes the challenges that can be found dealing with patients suffering from cutaneous steam burns and/or steam inhalation injuries. A steam injury to the airways or the skin can be directly life-threatening and should be treated with caution. This type of injury can lead to acute respiratory insufficiency and sometimes death. A case of a male patient with extensive cutaneous steam burns and a steam inhalation injury who passed away after 11 days of treatment is also presented to illustrate this review.

Level of evidence: Level V, Therapeutic; Risk/Prognostic Study.

Comparison of Thermal Burn-Induced and Excisional-Induced Scarring in Animal Models: A Review of the Literature

Significance: Scar formation is a natural result of mammalian wound healing. In humans and other mammals, however, deep dermal wounds and thermal injuries often result in formation of hypertrophic scars, leading to substantial morbidity and lending great importance to development of therapeutic modalities for burn scars. Clinical Issues: Thus, preclinical burn wound models that adequately simulate processes underlying human burn-induced wound healing, particularly those processes leading to chronic inflammation and development of hypertrophic scars, are critical to developing further treatment paradigms for clinical use. Approach: In this study, we review literature describing various burn models, focusing on their characteristics and the functional readouts that lead to generation of useful data. We also briefly discuss recent work using human ex vivo skin culture as an alternative to animal models, as well as our own development of rabbit ear wound models for burn scars, and assess the pros and cons of these models compared to other models. Future Direction: Understanding of the strengths and weaknesses of preclinical burn wound models will enable choice of the most appropriate wound model to answer particular clinically relevant questions, furthering research aimed at treating burn scars.

Amnion bilayer for dressing and graft replacement for delayed grafting of full-thickness burns; A study in a rat model

Burn is a common case in developing countries, with over half of fire-related deaths reported in Southeast Asia and full-thickness burns as a high mortality risk. Human amnion has been used as a wound dressing for centuries. In this study, a decellularised amnion overlaid with fibrin, “amnion bilayer (AB),” was used as a dressing immediately after burn and as a graft to replace the scar in Sprague-Dawley rats subjected to full-thickness burn model. The aim was to observe whether amnion bilayer can reduce damages in third-grade burn when skin replacement is deemed impossible. The burn was induced using an electrical solder, heated for 5 mins, and contacted on the rat’s bare skin for 20 s. AB was applied as a (i) dressing immediately after induction and graft after eschar removal. Two groups (n = 6) were compared: AB and Sofra-Tulle ^®, the National Hospital of Indonesia (NHI) protocol. Sections were stained with hematoxylin and eosin and Masson trichrome stains. Immunohistochemistry labelling was used to indicate scars (α-smooth muscle actin [α-SMA] and collagen-1) and angiogenesis (von Willebrand factor). Also, the macrophages inflammatory protein-3α (MIP-3α) indicates an early inflammatory process. The post dressing of the AB group demonstrated hair follicle remains and adipose tissue development. The NHI group appeared with a denatured matrix. Complete healing was seen in the AB group after 28 days with skin appendages similar to normal, while the NHI group showed no appendages in the centre of the actively inflamed area. The α-SMA was found in both groups. Collagen-1 was highly expressed in the NHI group, which led to a scar. Angiogenesis was found more in the AB group. The AB group had shown the capacity to accelerate complete healing and recover skin appendages better than the current protocol.

Transparent Air Filters with Active Thermal Sterilization

The worldwide proliferation of COVID-19 poses the urgent need for sterilizable and transparent air filters to inhibit virus transmission while retaining ease of communication. Here, we introduce copper nanowires to fabricate transparent and self-sterilizable air filters. Copper nanowire air filter (CNAF) allowed visible light penetration, thereby can exhibit facial expressions, helpful for better communication. CNAF effectively captured particulate matter (PM) by mechanical and electrostatic filtration mechanisms. The temperature of CNAF could be controlled by Joule-heating up to 100 °C with thermal stability. CNAF successfully inhibited the growth of E. coli because of the oligodynamic effect of copper. With heat sterilization, the antibacterial efficiency against G. anodireducens was greatly improved up to 99.3% within 10 min. CNAF showed high reusability with stable filtration efficiency and thermal antibacterial efficacy after five repeated uses. Our result suggests an alternative form of active antimicrobial air filter in preparation for the current and future pandemic situations.

Hydrogels for the management of second-degree burns: currently available options and future promise

Burn wounds result from exposure to hot liquids, chemicals, fire, electric discharge or radiation. Wound severity ranges from first-degree injury, which is superficial, to fourth-degree injury, which exposes bone, tendons and muscles. Rapid assessment of burn depth and accurate wound management in the outpatient setting is critical to prevent injury progression into deeper layers of the dermis. Injury progression is of particular pertinence to second-degree burns, which are the most common form of thermal burn. As our understanding of wound healing advances, treatment options and technologies for second-degree burn management also evolve. Polymeric hydrogels are a class of burn wound dressings that adhere to tissue, absorb wound exudate, protect from the environment, can be transparent facilitating serial wound evaluation and, in some cases, enable facile removal for dressing changes. This review briefly describes the burn level classification and common, commercially available dressings used to treat second-degree burns, and then focuses on new polymeric hydrogel burn dressings under preclinical development analyzing their design, structure and performance. The review presents the follow key learning points: (1) introduction to the integument system and the wound-healing process; (2) classification of burns according to severity and clinical appearance; (3) available dressings currently used for second-degree burns; (4) introduction to hydrogels and their preparation and characterization techniques; and (5) pre-clinical hydrogel burn wound dressings currently being developed.

A deep learning model for burn depth classification using ultrasound imaging

Identification of burn depth with sufficient accuracy is a challenging problem. This paper presents a deep convolutional neural network to classify burn depth based on altered tissue morphology of burned skin manifested as texture patterns in the ultrasound images. The network first learns a low-dimensional manifold of the unburned skin images using an encoder-decoder architecture that reconstructs it from ultrasound images of burned skin. The encoder is then re-trained to classify burn depths. The encoder-decoder network is trained using a dataset comprised of B-mode ultrasound images of unburned and burned ex vivo porcine skin samples. The classifier is developed using B-mode images of burned in situ skin samples obtained from freshly euthanized postmortem pigs. The performance metrics obtained from 20-fold cross-validation show that the model can identify deep-partial thickness burns, which is the most difficult to diagnose clinically, with 99% accuracy, 98% sensitivity, and 100% specificity. The diagnostic accuracy of the classifier is further illustrated by the high area under the curve values of 0.99 and 0.95, respectively, for the receiver operating characteristic and precision-recall curves. A post hoc explanation indicates that the classifier activates the discriminative textural features in the B-mode images for burn classification. The proposed model has the potential for clinical utility in assisting the clinical assessment of burn depths using a widely available clinical imaging device.

Moderate Heat-Assisted Gene Electrotransfer as a Potential Delivery Approach for Protein Replacement Therapy through the Skin

Gene-based approaches for protein replacement therapies have the potential to reduce the number of administrations. Our previous work demonstrated that expression could be enhanced and/or the applied voltage reduced by preheating the tissue prior to pulse administration. In the current study, we utilized our 16-pin multi-electrode array (MEA) and incorporated nine optical fibers, connected to an infrared laser, between each set of four electrodes to heat the tissue to 43 °C. For proof of principle, a guinea pig model was used to test delivery of reporter genes. We observed that when the skin was preheated, it was possible to achieve the same expression levels as gene electrotransfer without preheating, but with a 23% reduction of applied voltage or a 50% reduction of pulse number. With respect to expression distribution, preheating allowed for delivery to the deep dermis and muscle. This suggested that this cutaneous delivery approach has the potential to achieve expression in the systemic circulation, thus this protocol was repeated using a plasmid encoding Human Factor IX. Elevated Factor IX serum protein levels were detected by ELISA up to 100 days post gene delivery. Further work will involve optimizing protein levels and scalability in an effort to reduce application frequency.

Numerical evaluation of the duodenal mucosal resurfacing technique for the treatment of Type 2 diabetes

BACKGROUNDS AND OBJECTIVES

This work presents a numerical analysis of the Duodenal Mucosal Resurfacing (DMR) technique, which is a relatively new treatment for Type 2 diabetes that has been already tested in human beings. In this innovative strategy, an endoscopic catheter is placed inside the duodenum thus serving as a guide to an ablation device. A circumferential ablation is then performed by using a balloon filled with a hot fluid with pre- and post-cooling stages that allows for a controlled thermal procedure. Clinical outcomes indicate that the damaged duodenal lining induces a better control of glycemic levels. Therefore, a numerical evaluation of the efficiency of this treatment is carried out by utilizing the bioheat transfer equation in the transient form.

METHODS

The finite volume method is used in the discretization of the energy equation and the results are verified by exploring the same mathematical model in a commercial finite-element package. The Arrhenius criterion for the evaluation of the thermally affected tissue is employed in this study.

RESULTS

A systematic analysis of the simulations is performed by investigating two scenarios: one in which the lifting of the mucosal duodenum layer is achieved and another one where the lifting strategy is not implemented. The role of the magnitude of the blood perfusion coefficient, tissue thermal conductivity, peak, pre- and post-cooling temperatures is thoroughly explored, especially in connection with the evaluation of the extent of the thermally affected region.

CONCLUSIONS

According to the simulations discussed in the present contribution, this treatment is capable of accurately targeting the cells in the mucosal layer without significantly affecting the outermost stratum of the organ if the lifting process is applied. However, for the case without lifting, the muscularis propria layer may reach temperatures above 42 °C during a short time interval and thus the treatment should be considered with caution by the physician.

Preclinical efficacy study of a porous biopolymeric scaffold based on gelatin-hyaluronic acid-chondroitin sulfate in a porcine burn injury model: role of critical molecular markers (VEGFA, N-cadherin, COX-2), gamma sterilization efficacy and a comparison of healing potential to Integra™

Development of scaffold from biopolymers can ease the requirements for donor skin autograft and plays an effective role in the treatment of burn wounds. In the current study, a porous foam based, bilayered hydrogel scaffold was developed using gelatin, hyaluronic acid and chondroitin sulfate (G-HA-CS). The fabricated scaffold was characterized physicochemically for pre- and post-sterilization efficacy by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).In-vitrostudies proved that the scaffold promoted cellular proliferation. The efficacy of G-HA-CS scaffold was compared with Integra™ at different time points (7, 14, 21 and 42 days), in a swine second degree burn wound model. Remarkable healing potential of the scaffold was evident from the wound contraction rate, reduction of IL-6, TNF-αand C3. The expression of healing markers TGF-β1 and collagen 1 revealed significant skin regeneration with regulated fibroblast activation towards the late phase of healing (p< 0.001 at day 21 and 42 vs. control). Expression of Vascular Endothelial Growth Factor A (VEGFA), vimentin and N-cadherin were found to favor angiogenesis and skin regeneration. Mechanistically, scaffold promoted wound healing by modulation of CD-45, cyclooxygenase-2 and MMP-2. Thus, the promising results with foam based scaffold, comparable to Integra™ in swine burn injury model offer an innovative lead for clinical translation for effective management of burn wound.

Heated Humidifiers for Noninvasive Respiratory Support and the Risk of Burns in Neonates: A Bench Evaluation

BACKGROUND

User errors in managing heated humidifiers (HHs) have been suggested to be a source of nasal burns in newborns treated with nasal CPAP. This study evaluated the risk of burns by reproducing 3 typical errors concerning the use of HHs.

METHODS

Six HHs were tested on a bench in a traditional nasal CPAP setup: PMH5000, Aircon (Wilamed); MR730, MR850, MR950 (Fisher & Paykel); and H900 (Hamilton). Temperature was measured at the end of the inspiratory tubing limb. Errors tested were (1) misconnection of the HH thermal probes (NoProbe), (2) absence of gas flow while the HH is on (NoFlow), and (3) unsuitable repeated acknowledgment of the HH alarm (NoAlarm). These errors were combined in 3 standardized scenarios: (1) NoProbe + NoFlow + NoAlarm; (2) NoProbe + NoAlarm, and (3) NoFlow + NoAlarm. The NoProbe + NoFlow + NoAlarm and NoProbe + NoAlarm scenarios were not tested in the H900 and MR950 because the proprietary circuits of these HHs are equipped with embedded probes.

RESULTS

For each HH, the highest inspiratory gas temperature (HIGT) and the rating on a self-designed risk-of-burn scale (ie, no risk, moderate risk, or severe risk) were reported. In the NoProbe + NoFlow + NoAlarm scenario, the risk was severe for the MR730, PMH5000, MR850, and Aircon, with HIGTs of > 65°C, 58°C, 56°C, and > 65°C, respectively. In the NoProbe + NoAlarm scenario, the risk was also severe for the same 4 HHs, with HIGTs of 56°C, 47°C, 56°C, and 48°C, respectively. In the NoFlow + NoAlarm scenario, the risk was severe for the PMH5000, Aircon, and H900, with HIGTs of 52°C, > 65°C, and 49°C, respectively, and moderate for the MR730, MR850, and MR950, with HIGTs of 45°C, 47°C, and 44°C, respectively).

CONCLUSIONS

In case of misuse, 5 of the 6 tested devices presented a severe risk of inducing skin burns, whereas the MR950 presented a moderate risk.

Burn-induced heterotopic ossification from incidence to therapy: key signaling pathways underlying ectopic bone formation

Burn injury is one of the potential causes of heterotopic ossification (HO), which is a rare but debilitating condition. The incidence ranges from 3.5 to 5.6 depending on body area. Burns that cover a larger percentage of the total body surface area (TBSA), require skin graft surgeries, or necessitate pulmonary intensive care are well-researched risk factors for HO. Since burns initiate such complex pathophysiological processes with a variety of molecular signal changes, it is essential to focus on HO in the specific context of burn injury to define best practices for its treatment. There are numerous key players in the pathways of burn-induced HO, including neutrophils, monocytes, transforming growth factor-β1-expressing macrophages and the adaptive immune system. The increased inflammation associated with burn injuries is also associated with pathway activation. Neurological and calcium-related contributions are also known. Endothelial-to-mesenchymal transition (EMT) and vascularization are known to play key roles in burn-induced HO, with hypoxia-inducible factor-1 (HIF-1) and vascular endothelial growth factor (VEGF) as potential initiators. Currently, non-steroidal anti-inflammatory drugs (NSAIDs) and radiotherapy are effective prophylaxes for HO. Limited joint motion, ankylosis and intolerable pain caused by burn-induced HO can be effectively tackled via surgery. Effective biomarkers for monitoring burn-induced HO occurrence and bio-prophylactic and bio-therapeutic strategies should be actively developed in the future.

Recent perspectives of nanotechnology in burn wounds management: a review

OBJECTIVE

The burden of the management of problematic skin wounds characterised by a compromised skin barrier is growing rapidly. Almost six million patients are affected in the US alone, with an estimated market of $25 billion annually. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. Novel strategies are needed for faster healing by reducing infection, moisturising the wound, stimulating the healing mechanisms, speeding up wound closure and reducing scar formation.

METHODS

A systematic review of qualitative studies was conducted on the recent perspectives of nanotechnology in burn wounds management. Pubmed, Scopus, EMBASE, CINAHL and PsychINFO databases were all systematically searched. Authors independently rated the reporting of the qualitative studies included. A comprehensive literature search was conducted covering various resources up to 2018-2019. Traditional techniques aim to simply cover the wound without playing any active role in wound healing. However, nanotechnology-based solutions are being used to create multipurpose biomaterials, not only for regeneration and repair, but also for on-demand delivery of specific molecules. The chronic nature and associated complications of nonhealing wounds have led to the emergence of nanotechnology-based therapies that aim at facilitating the healing process and ultimately repairing the injured tissue.

CONCLUSION

Nanotechnology-based therapy is in the forefront of next-generation therapy that is able to advance wound healing of hard-to-heal wounds. In this review, we will highlight the developed nanotechnology-based therapeutic agents and assess the viability and efficacy of each treatment. Herein we will explore the unmet needs and future directions of current technologies, while discussing promising strategies that can advance the wound-healing field.

A retrospective surveillance of the prophylactic antibiotics for debridement surgery in burn patients

Burn injury is trauma with a high risk of infection. A method that can be used to prevent and decrease the incidence of infection and accelerate wound healing is debridement. The use of prophylactic antibiotics was considered in debridement to minimize surgical site infection. This study's objective was to characterize the usage of prophylactic antibiotics for debridement in burn patients, including the selection, dose, and route of administration. The second objective was to quantitatively calculate the use of prophylactic antibiotics using ATC/DDD. This was a retrospective study in burn patients admitted to the Dr. Soetomo Hospital's burn unit between 2017 and 2020. Ninety burn patients meet the inclusion criteria enrolled in this study. There were eight prophylactic antibiotics for debridement in this study. Only four from eight antibiotics met the guidelines for prophylactic antibiotics before surgery. All prophylactic antibiotics were given intravenously. The most common prophylactic antibiotics were cefazolin (39%) and followed by ceftazidime (31%) and ceftriaxone (11%). Ceftazidime, cefoperazone, amikacin, and meropenem were used as therapeutic antibiotics to treat burn infection and continued as prophylactic before debridement surgery. Cefazolin and ceftriaxone were the most antibiotics that comply their dose with the guideline. The total of DDD/100 operations was 6.23 and cefazolin was the highest consumed, 3.10 DDD/100 operations. The mortality rate in our study was 33%. For those who survived, there was a significant correlation between % TBSA and length of stay also debridement frequency. Our study concluded there was a difference between daily practice in the hospital and in the guidelines. Improvements were needed to use prophylactic antibiotics more precisely regarding quantity and choice of the type of antibiotics.

Gastric ablation as a novel technique for modulating electrical conduction in the in vivo stomach

Gastric motility is coordinated by underlying bioelectrical "slow wave" activity. Slow wave dysrhythmias are associated with motility disorders, including gastroparesis, offering an underexplored potential therapeutic target. Although ablation is widely used to treat cardiac arrhythmias, this approach has not yet been trialed for gastric electrical abnormalities. We hypothesized that ablation can create localized conduction blocks and modulate slow wave activation. Radiofrequency ablation was performed on the porcine serosa in vivo, encompassing a range of parameters (55-85°C, adjacent points forming a line, 5-10 s/point). High-resolution electrical mapping (16 × 16 electrodes; 6 × 6 cm) was applied to define baseline and acute postablation activation patterns. Tissue damage was evaluated by hematoxylin and eosin and c-Kit stains. Results demonstrated that RF ablation successfully induced complete conduction block and a full thickness lesion in the muscle layer at energy doses of 65-75°C for 5-10 s/point. Gastric ablation may hold therapeutic potential for gastric electrical abnormalities in the future.NEW & NOTEWORTHY This study presents gastric ablation as a new method for modulating slow wave activation and propagation in vivo, by creating localized electrical conduction blocks in the stomach, validated by high-resolution electrical mapping and histological tissue analysis. The results define the effective energy dose range for creating conduction blocks, while maintaining the mucosal and submucosal integrity, and demonstrate the electrophysiological effects of ablation. In future, gastric ablation can now be translated toward disrupting dysrhythmic slow wave activation.

Water heating immersion rod fatalities and their injury pattern characteristics

Immersion rod is a very low-cost electrical device. It is based on simple working principle and widely used in developing nations to heat water for various domestic needs. However, the literature about electrocution caused by it is nearly absent. This is despite its usage being potentially hazardous, with almost sure fatal outcome in cases of mishandling. Data was gathered from 2011 to 2020, via inquest and autopsy reports, regarding electrocution deaths related to it. 6 cases were identified. All consisted of females in domestic settings, as the unique epidemiology in stark contrast to the existing literature on electrocution fatalities worldwide. Injury patterns in a few cases resembled those typical of high voltage electrocution, in these low voltage fatalities. Characteristics of joule burns showed sub-patterns, deviant from electrocution related to other appliances and was again unreported previously. Spark burns and scalds were patterns, quite diagnostic of immersion rod fatalities. A typical pattern for a multitude of injuries in each case is brevity of this study. Injury patterns are presented as a classical guide for further growth of the literature on these types of fatalities.

Laser-induced optothermal response of gold nanoparticles: From a physical viewpoint to cancer treatment application

Gold nanoparticles (GNPs)-based photothermal therapy (PTT) is a promising minimally invasive thermal therapy for the treatment of focal malignancies. Although GNPs-based PTT has been known for over two decades and GNPs possess unique properties as therapeutic agents, the delivery of a safe and effective therapy is still an open question. This review aims at providing relevant and recent information on the usage of GNPs in combination with the laser to treat cancers, pointing out the practical aspects that bear on the therapy outcome. Emphasis is given to the assessment of the GNPs' properties and the physical mechanisms underlying the laser-induced heat generation in GNPs-loaded tissues. The main techniques available for temperature measurement and the current theoretical simulation approaches predicting the therapeutic outcome are reviewed. Topical challenges in delivering safe thermal dosage are also presented with the aim to discuss the state-of-the-art and the future perspective in the field of GNPs-mediated PTT.

Combining Chemistry and Engineering for Hepatocellular Carcinoma: Nano-Scale and Smaller Therapies

Primary liver cancer, or hepatocellular carcinoma (HCC), is a major worldwide cause of death from carcinoma. Most patients are not candidates for surgery and medical therapies, including new immunotherapies, have not shown major improvements since the modest benefit seen with the introduction of sorafenib over a decade ago. Locoregional therapies for intermediate stage disease are not curative but provide some benefit. However, upon close scrutiny, there is still residual disease in most cases. We review the current status for treatment of intermediate stage disease, summarize the literature on correlative histopathology, and discuss emerging methods at micro-, nano-, and pico-scales to improve therapy. These include transarterial hyperthermia methods and thermoembolization, along with microfluidics model systems and new applications of mass spectrometry imaging for label-free analysis of pharmacokinetics and pharmacodynamics.

Incidence of and Risk Factors for Medical Adhesive-Related Skin Injuries Among Patients: A Cross-sectional Study

PURPOSE

We explored the incidence of medical adhesive-related skin injuries (MARSIs) that developed in an intensive care unit (ICU) and identified the relevant risk factors associated with these skin injuries.

DESIGN

Cross-sectional.

SUBJECTS AND SETTING

A 29-bed adult general ICU of a tertiary teaching hospital affiliated with Zhejiang University in southeast China.

METHODS

Data regarding MARSIs, skin assessments, and related nursing procedures were collected between January 2018 and May 2018. The incidence of MARSIs was calculated, and the associated risk factors were analyzed using a logistic regression model.

RESULTS

During the study period, 430 patients were evaluated, of which 55 experienced MARSIs (4 prior to hospitalization in our ICU). The overall MARSI incidence rate was 11.86% (51/430); mechanical damage including epidermal stripping (72.7%; 40/55) and skin tears (14.5%; 8/55) was the most common MARSI. Moderate-to-severe edema, hyperthermia, and the use of certain medicines such as immunosuppressants and anticoagulants were independent risk factors for MARSIs.

CONCLUSIONS

Critically ill patients are at a high risk of MARSIs in China. Preventive measures and good clinical nursing practice are needed to ensure patient safety.

Properties of Thermal Analgesia in a Human Chronic Low Back Pain Model

Purpose

For years, heat has been used for comfort and analgesia is recommended as a first-line therapy in many clinical guidelines. Yet, there are questions that remain about the actual effectiveness of heat for a condition as common as chronic low back pain, and factors such as time of onset, optimal temperature, and duration of effect.

Materials and Methods

A randomized double-blinded controlled trial was designed to compare the analgesic response to heat delivered via pulses at 45°C (experimental group, N=49) to steady heat at 37°C (control group, N=51) in subjects with longstanding low back pain. Treatment lasted 30 minutes with follow-up out to four hours. The hypothesis was that the experimental group would experience a higher degree of analgesia compared to the control group. Time of onset and duration of effect were also measured.

Results

Both groups were similar in average duration of pain (10.3 years). The primary outcome measure was pain reduction at 30 minutes after the end of treatment, using a 10-points numeric pain scale. Reduction in pain was greater for the experimental group than the control group (difference in mean reduction = 0.72, 95% CI 0.15–1.29, p = 0.014). Statistically significant differences in pain levels were observed from the first measure at 5 minutes of treatment through 120 minutes after completion of treatment. Reduction in pain associated movement was greater in the active heat group than the placebo group (p = 0.04).

Conclusion

High-level pulsed heat (45°C) produced significantly more analgesia as compared to steady heat at 37°C at the primary end point and for an additional 2 hours after treatment. The onset of analgesia was rapid, <5 minutes of treatment. The results of this trial provide insight into the mechanisms and properties of thermal analgesia that are not well understood in a chronic low back pain model.

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Raman spectroscopy accurately classifies burn severity in an ex vivo model

Accurate classification of burn severities is of vital importance for proper burn treatments. A recent article reported that using the combination of Raman spectroscopy and optical coherence tomography (OCT) classifies different degrees of burns with an overall accuracy of 85% [1]. In this study, we demonstrate the feasibility of using Raman spectroscopy alone to classify burn severities on ex vivo porcine skin tissues. To create different levels of burns, four burn conditions were designed: (i) 200°F for 10s, (ii) 200°F for 30s, (iii) 450°F for 10s and (iv) 450°F for 30s. Raman spectra from 500-2000cm^-1 were collected from samples of the four burn conditions as well as the unburnt condition. Classifications were performed using kernel support vector machine (KSVM) with features extracted from the spectra by principal component analysis (PCA), and partial least-square (PLS). Both techniques yielded an average accuracy of approximately 92%, which was independently evaluated by leave-one-out cross-validation (LOOCV). By comparison, PCA+KSVM provides higher accuracy in classifying severe burns, while PLS performs better in classifying mild burns. Variable importance in the projection (VIP) scores from the PLS models reveal that proteins and lipids, amide III, and amino acids are important indicators in separating unburnt or mild burns (200°F), while amide I has a more pronounced impact in separating severe burns (450°F).

Heater-Associated Erythema Ab Igne: Case Report and Review of Thermal-Related Skin Conditions

Erythema ab igne is a thermal-associated skin condition that can occur secondary to persistent direct or indirect contact with heat. Historically, erythema ab igne has been linked to fireplace and stove exposures; more recently, it has been associated with heaters, hot water bottles, and laptops. A 48-year-old woman presented for the evaluation of hyperpigmented, reticulated macular lesions on her distal legs. Additional history revealed that she had developed erythema ab igne secondary to the use of a space heater underneath her desk at work. Her skin condition stopped progressing with removal of the causative agent. In addition to erythema ab igne, heat-related skin conditions include basal cell carcinomas and squamous cell carcinomas, burns, erythromelalgia, subtypes of urticaria, and ultraviolet-associated disorders. Awareness of thermal-associated skin conditions enables the clinician to establish the appropriate diagnosis based on the associated history of the condition, the morphology of the skin lesion, and, if necessary, correlation with the skin biopsy findings of the cutaneous condition.

Real-time Burn Classification using Ultrasound Imaging

This article presents a real-time approach for classification of burn depth based on B-mode ultrasound imaging. A grey-level co-occurrence matrix (GLCM) computed from the ultrasound images of the tissue is employed to construct the textural feature set and the classification is performed using nonlinear support vector machine and kernel Fisher discriminant analysis. A leave-one-out cross-validation is used for the independent assessment of the classifiers. The model is tested for pair-wise binary classification of four burn conditions in ex vivo porcine skin tissue: (i) 200 °F for 10 s, (ii) 200 °F for 30 s, (iii) 450 °F for 10 s, and (iv) 450 °F for 30 s. The average classification accuracy for pairwise separation is 99% with just over 30 samples in each burn group and the average multiclass classification accuracy is 93%. The results highlight that the ultrasound imaging-based burn classification approach in conjunction with the GLCM texture features provide an accurate assessment of altered tissue characteristics with relatively moderate sample sizes, which is often the case with experimental and clinical datasets. The proposed method is shown to have the potential to assist with the real-time clinical assessment of burn degrees, particularly for discriminating between superficial and deep second degree burns, which is challenging in clinical practice.

Burn-related Collagen Conformational Changes in ex vivo Porcine Skin using Raman Spectroscopy

This study utilizes Raman spectroscopy to analyze the burn-induced collagen conformational changes in ex vivo porcine skin tissue. Raman spectra of wavenumbers 500-2000 cm^-1 were measured for unburnt skin as well as four different burn conditions: (i) 200 °F for 10 s, (ii) 200 °F for the 30 s, (iii) 450 °F for 10 s and (iv) 450 °F for 30 s. The overall spectra reveal that protein and amino acids-related bands have manifested structural changes including the destruction of protein-related functional groups, and transformation from α-helical to disordered structures which are correlated with increasing burn severity. The deconvolution of the amide I region (1580-1720 cm^-1) and the analysis of the sub-bands reveal a change of the secondary structure of the collagen from the α-like helix dominated to the β-aggregate dominated one. Such conformational changes may explain the softening of mechanical response in burnt tissues reported in the literature.

Sauromatum guttatum extract promotes wound healing and tissue regeneration in a burn mouse model via up-regulation of growth factors

Contexts: Sauromatum guttatum (Wall.) Schott (Araceae) has been traditionally used for the treatment of wounds. Objectives: This study evaluates the healing and tissue regeneration potential of S. guttatum extract in burn wounds. Materials and methods: S. guttatum extract was analysed using various chemical tests, thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Moreover, the extract was tested against burn associated bacteria and minimum inhibitory concentration (MIC) was also calculated. Wound healing and tissue regeneration potential was assessed using a thermally induced burn BALBc mouse model. S. guttatum extract (2% w/w) prepared in petroleum jelly, vehicle and positive control [silver sulfadiazine (SD)] groups was applied three times a day. The treatment was continued for 15 d and wound closure was measured and photographed on day 5, 10 and 15. The burnt tissues excised from wounds were subjected to histological and comparative gene expression analysis. Results: The results of the chemical tests indicated the presence of alkaloids, saponins, phenols, phytosterols, tannins, and flavonoids, while TLC and HPLC analysis indicated the presence of various compounds. The extract showed excellent activity against the tested pathogens. The lowest MIC (125 µg/mL) was observed against Staphylococcus aureus. A considerable decrease in wound area (72%) was observed in extract-treated group. Histological examination of extract-treated group showed good signs of wound healing with complete re-epithelialization and better tissue regeneration. Comparative gene expression analysis revealed the up-regulation of wound healing related PDGF, EGF and FGF genes. Conclusions: S. guttatum extract may be used to isolate bioactive constituents for the treatment of burn wounds.