Improving Surgical Treatment of Skin Burns to Reduce the Incidence of Pathologic Scarring

Background: In some parts of the world, the incidence of postburn pathologic scars reaches 16%. One should understand reconstructive surgery techniques and prioritize scar prevention during burn wound treatment. Inadequate wound management affects scar tissue formation and may cause pathologic scarring. Optimal timing of skin restoration operations reduces the risk of postoperative complications.Objective: To demonstrate that the surgical removal of fibrotic dermis and granulation tissue is feasible to reduce the incidence of pathologic scarring.Materials and methods: We studied treatment results in 57 patients with deep burns who were divided into 2 groups based on surgical treatment types before autologous skin grafting. Group 1 underwent total excision of granulation tissue, removal of fibrotic dermis, and excision of wound edges on day 27–31 after the injury. On day 22–28 postburn, group 2 had tangential excision of granulation tissue, removal of the upper skin layers only (the fibrotic dermis preserved), and then autologous skin grafting. The patients were followed up postoperatively at 1, 6, 12 months. During the examinations we assessed the formed scar tissue and perfusion of the burn injuries. Types and features of the scar tissue were identified by histologic examination of biopsy tissues.Results: We identified statistically significant differences between the analyzed patient groups based on the perfusion values measured by laser Doppler flowmetry and found a relationship between surgical approaches, wound perfusion, and the incidence of pathologic scarring.Conclusions: When early debridement is unfeasible, the preferred surgical approach for deep burns is a staged wound cleansing from necrotic tissue followed by total removal of granulation tissue and fibrotic dermis, and finally autologous skin grafting. This approach prevents pathologic scarring

Treatment of pain syndrome after aesthetic breast surgery with botulinum toxin type A

Objective. To justify the possibility of using botulotoxin type A for the prevention of pain syndrome after aesthetic endoprosthesis of the mammary glands.Material and Methods. The study included 72 women aged between 21 and 45 to whom were scheduled to perform breast endoprosthesis with silicone implants. All patients were divided into two groups: the first group included 38, the second group – 34 people. Two weeks before the expected date of surgery, botulotoxin type A in an amount of 100 U was injected into the patients of the first group to reduce pain syndrome in the pectoralis major muscle. Patients of the second (control) group were injected with a 0.9% NaCl solution (placebo effect) into the pectoralis major muscle. All patients underwent electroneuromyography (ENMG) to assess the denervation of the pectoralis major muscle before drug administration and two weeks after.Results. The intensity of pain syndrome was evaluated on the 1st-2nd day after surgery using a special questionnaire. In women of the first group, who were injected with botulinum toxin type A two weeks prior the intended surgery, a decrease in the intensity of the pain syndrome was observed, which in most cases allowed not to take analgesics at all. In women of the second group who were injected with a 0.9% NaCl solution, the severity of the pain syndrome reached its maximum values (according to the questionnaire), which required the prescription of analgesics, including narcotic ones, to reduce the severity of the pain syndrome. According to ENMG, when using botulotoxin type A by injecting into the pectoralis major muscle, denervation indices reached 55% compared to the initial ones, while using the saline solution, the ENMG indices did not change.Conclusion. Clinical use of botulotoxin type A injections into the pectoralis major muscle will improve the results of pain syndrome treatment after endoprosthetics of the mammary glands with implants in aesthetic surgery

An All-Cryogenic THz Transmission Spectrometer

This paper describes a THz transmission spectrometer for the spectral range of 2-65 cm^-1 (100 GHz to 2 THz) with a spectral resolution of at least 1.8 cm^-1 (50 GHz) where the source, sample, and detector are all fully contained in a cryogenic environment. Cyclotron emission from a two-dimensional electron gas heated with an electrical current serves as a magnetic field tunable source. The spectrometer is demonstrated at 4.2 K by measuring the resonant cyclotron absorption of a second two dimensional electron gas. Unique aspects of the spectrometer are that 1) an ultra-broadband detector is used and 2) the emitter is run quasi-continuously with a chopping frequency of only 1 Hz. Since optical coupling to room temperature components is not necessary, this technique is compatible with ultra-low temperature (sub 100 mK) operation.Comment: 7 pages, 5 figures. Author affiliation and funding acknowledgements clarifie

Effectiveness of Autologous Platelet-Rich Plasma and Stromal Vascular Fraction in Autologous Skin Grafting

Introduction: Despite the medical advances, burns remain a serious challenge and require new and promising treatment options, such as biomedical technologies with a high potential for burn wound treatment. However, high cost and complexity of biotechnologies limit their routine use, but autologous tissues, such as stromal vascular fraction (SVF) and autologous platelet-rich plasma (PRP), overcome these shortcomings.   Objective: To demonstrate a successful case of using a combination of adipose-derived SVF and autologous PRP during autologous skin grafting in a severely burned patient.   Material and methods: We present a successful case of 84-year-old Patient B. treated at Saint Petersburg I. I. Dzhanelidze Research Institute of Emergency Medicine in September-October 2022. He was diagnosed with a 11% (6%) / II-III degree flame burn of the head, neck, trunk, and upper extremities and first-degree inhalation injury. At the first stage, the general condition of the patient was stabilized, and he was prepared for surgery. At the second stage, on day 25 of treatment we performed skin grafting using split-thickness autografts with rare perforations and application of SVF and autologous PRP on a burn wound. We evaluated the treatment effectiveness using planimetry, cytology, and histology.   Results: We observed complete engraftment of the autograft with no lysis or rejection during the first dressing change on day 3 after surgery and complete skin restoration on day 11. Cytologic findings over time showed an active decrease in inflammatory cells and an increase in regenerative cells, indicating successful wound healing. Histology demonstrated formation of normal stratified squamous epithelium with areas of hyperkeratosis and young granulation tissue in the superficial layers of the dermis on day 6.   Conclusions: Our case demonstrated that the combination of SVF and autologous PRP facilitates split-thickness skin autograft engraftment

Double Parton Scattering Singularity in One-Loop Integrals

We present a detailed study of the double parton scattering (DPS) singularity, which is a specific type of Landau singularity that can occur in certain one-loop graphs in theories with massless particles. A simple formula for the DPS singular part of a four-point diagram with arbitrary internal/external particles is derived in terms of the transverse momentum integral of a product of light cone wavefunctions with tree-level matrix elements. This is used to reproduce and explain some results for DPS singularities in box integrals that have been obtained using traditional loop integration techniques. The formula can be straightforwardly generalised to calculate the DPS singularity in loops with an arbitrary number of external particles. We use the generalised version to explain why the specific MHV and NMHV six-photon amplitudes often studied by the NLO multileg community are not divergent at the DPS singular point, and point out that whilst all NMHV amplitudes are always finite, certain MHV amplitudes do contain a DPS divergence. It is shown that our framework for calculating DPS divergences in loop diagrams is entirely consistent with the `two-parton GPD' framework of Diehl and Schafer for calculating proton-proton DPS cross sections, but is inconsistent with the `double PDF' framework of Snigirev.Comment: 29 pages, 8 figures. Minor corrections and clarifications added. Version accepted for publication in JHE

Evaluating the effectiveness of combined use of non-thermal atmospheric pressure plasma and frequently-modulated electric field signal in skin wound healing

Background. Scientists around the world are interested in applying physical phenomena to various fields of science. The development of entire areas united by one concept (‘plasma medicine’, etc.) stands as an outstanding example. This study focuses on only two concepts of interest, which are plasma jet and electric field, as far as results of their combined use in clinical practice and in surgery remain understudied. Objective. Experimental evaluation of the effectiveness of physical methods of treatment in skin wound healing. Material and Methods. Animal testing involved 45 small laboratory animals (rats). They were divided into 5 groups of 9 according to methods for experimental wound healing. To generate the plasma jet, a portable generator was used, which is the original development of specialists of the Peter the Great St. Petersburg Polytechnic University. Planimetric and histological measurements were analysed. The antibacterial effectiveness of methods under research was investigated using Staphylococcus aureus 209P, cultivated in vitro on 6- and 12-millimeter discs. Discussion. A combination of non-thermal atmospheric pressure plasma and frequency-modulated electric field signal exhibited the ability to accelerate eschar separation by 52.1% (p < 0.05) and stimulate restorative regeneration by 56% (p < 0.05). Combination of physical methods of treatment demonstrated pronounced antibacterial effect. A histological examination on biopsy sample on the 21st day of observation revealed formed (mature) granulations and large number of newly formed vessels. The cellular composition of epidermal basement membrane showed high level of differentiation. Conclusion. The data obtained suggest that the use of the proposed methods in clinical practice will improve the treatment process of the patients with wounds of different etiology

Multiple Parton Interactions in Z+jets production at the LHC. A comparison of factorized and non--factorized double parton distribution functions

We examine the contribution of Multiple Parton Interactions to Z+n-jets production at the LHC, n=2,3,4, where the Z boson is assumed to decay leptonically. We compare the results obtained with the correlated GS09 double parton distribution function with those obtained with two instances of fully factorized single parton distribution functions: MSTW2008LO and CTEQ6LO. It appears quite feasible to measure the MPI contribution to Z+2/3/4 jets already in the first phase of the LHC with a total luminosity of one inverse femtobarn at 7 TeV. If as expected the trigger threshold for single photons is around 80 GeV, Z+2-jets production may well turn out to be more easily observable than the gamma+3-jets channel. The MPI cross section is dominated by relatively soft events with two jets balancing in transverse momentum.Comment: 15 pages, 3 plot