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1.
Artigo em Inglês | MEDLINE | ID: mdl-38647991

RESUMO

Patients with burn injury and inhalation injury are highly susceptible to infectious complications, including opportunistic pathogens, due to the loss of skin cover and mucosal damage of respiratory tract as well as the disruption of homeostasis. This case report, a 34-year-old man suffered critical burns, provides the first literature description of triple-impact immunoparalysis (critical burns, inhalation injury, and SARS-CoV-2 infection), leading to a lethal multifocal infection caused by several fungi including very rare environmental representatives Metschnikowia pulcherrima and Wickerhamomyces anomalus. The co-infection by these common environmental yeasts in a human is unique and has not yet been described in the literature. Importantly, our patient developed refractory septic shock and died despite targeted antifungal therapy including the most potent current antifungal agent-isavuconazole. It can be assumed that besides immunoparalysis, effectiveness of therapy by isavuconazole was impaired by the large distribution volume in this case. As this is a common situation in intensive care patients, routine monitoring of plasmatic concentration of isavuconazole can be helpful in personalization of the treatment and dose optimization. Whatmore, many fungal species often remain underdiagnosed during infectious complications, which could be prevented by implementation of new methods, such as next-generation sequencing, into clinical practice.

2.
Int J Low Extrem Wounds ; 22(1): 200-207, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33856245

RESUMO

Necrotizing fasciitis is a life-threatening skin and soft tissue infection associated with high morbidity and mortality in adult patients. This infection can present as either type 1 infection caused by a mixed microflora (Streptococci, Enterobacteriacae, Bacteroides sp., and Peptostreptococcus sp.), most commonly developing in patients after surgery or in diabetic patients, or as type 2. The latter type is monomicrobial and, usually, caused by group A Streptococci. Rarely, this type can be also caused by other pathogens, such as Vibrio vulnificus. V vulnificus is a small mobile Gram-negative rod capable of causing 3 types of infections in humans-gastroenteritis, primary infection of the vascular bed, and wound infections. If infecting a wound, V vulnificus can cause a life-threatening condition-necrotizing fasciitis. We present a rare case of necrotizing fasciitis developing after an insect bite followed by exposure to the seawater. Rapid propagation of the infectious complication in the region of the right lower limb led to a serious consideration of the necessity of amputation. Due to the clearly demarcated necroses and secondary skin and soft tissue infection caused by a multiresistant strain of Acinetobacter baumannii, we, however, resorted to the use of selective chemical necrectomy using 40% benzoic acid-a unique application in this kind of condition. The chemical necrectomy was successful, relatively gentle and thanks to its selectivity, vital parts of the limb remained preserved and could have been subsequently salvaged at minimum blood loss. Moreover, the antimicrobial effect of benzoic acid led to rapid decolonization of the necrosis and wound bed preparation, which allowed us to perform defect closure using split-thickness skin grafts. The patient subsequently healed without further complications and returned to normal life.


Assuntos
Acinetobacter baumannii , Fasciite Necrosante , Infecções dos Tecidos Moles , Vibrioses , Vibrio vulnificus , Adulto , Humanos , Fasciite Necrosante/diagnóstico , Infecções dos Tecidos Moles/diagnóstico , Infecções dos Tecidos Moles/complicações , Vibrioses/complicações
3.
Phys Chem Chem Phys ; 23(36): 20379-20387, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34491256

RESUMO

Adsorption of molecular materials with tailored chemical properties represents a new and promising avenue to non-destructively dope silicon. Dithiocarboranes possess large permanent dipoles and readily form stable monolayers on a variety of substrates. Here we use density functional theory to investigate the doping of hydrogen-passivated Si(100) substrates through the adsorption of dithiocarborane molecules. We find that dithiocarboranes can both physisorb and chemisorb on the substrate. Chemisorbed structures arise when a S atom in the molecular linker group replaces a surface H atom. We establish the formation of these Si-molecule bonds and characterize their mechanical and thermal stability. Analysis of the calculated electronic structure of adsorbed interfaces shows that carborane adsorption does not result in interface gap states. The band gap in adsorbed junctions is defined by Si states and its magnitude is almost unchanged with respect to the clean Si slab. The large carborane electrostatic dipole results in the downwards shift of Si spectral features by 0.3 eV, reducing the hole injection barrier by this amount with respect to the pristine Si substrate. Molecular dynamics simulations reveal these structural and electronic features to be stable at room temperature. Our work shows that molecular adsorbates having large electrostatic dipoles are a promising strategy to non-destructively dope semiconductor substrates.

4.
Microorganisms ; 9(9)2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34576832

RESUMO

Wohlfahrtiimonas chitiniclastica are bacteria that cause rare infections, typically associated with the infestation of an open wound with fly larvae. Here, we present a unique case report of the first W. chitiniclastica isolation from a burn wound with accidental myiasis in a 63-year-old homeless man and a literature review focused on human infections caused by these bacteria. So far, 23 cases of infection with W. chitiniclastica have been reported; in 52% of these, larvae were found in the wound area. Most of these cases suffered from chronic non-healing wound infections but none of these were burn injuries. The overall fatality rate associated directly with W. chitiniclastica in these cases was 17%. Infections with parasitic larvae occur in moderate climates (especially in people living in poor conditions); therefore, an infection with rare bacteria associated with accidental myiasis, such as W. chitiniclastica, can be expected to become more common there. Thus, in view of the absence of recommendations regarding the treatment of patients with accidental myiasis and, therefore, the risk of infection with W. chitiniclastica or other rare pathogens, we provide a list of recommendations for the treatment of such patients. The importance of meticulous microbial surveillance using molecular biological methods to facilitate the detection of rare pathogens is emphasized.

5.
J Fungi (Basel) ; 7(6)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207136

RESUMO

Infectious complications are responsible for the majority of mortalities and morbidities of patients with critical burns. Although bacteria are the predominant etiological agents in such patients, yeasts and fungi have become relatively common causes of infections over the last decade. Here, we report a case of a young man with critical burns on 88% TBSA (total body surface area) arising as a part of polytrauma. The patient's history of orthotopic liver transplantation associated with the patient's need to use combined immunosuppressant therapy was an additional complication. Due to deep burns in the forearm region, we have (after a suitable wound bed preparation) applied a new bi-layered dermal substitute. The patient, however, developed a combined fungal infection in the region of this dermal substitute caused by Trichoderma longibrachiatum and Aspergillus fischeri (the first case ever reported). The infection caused the loss of the split-thickness skin grafts (STSGs); we had to perform repeated hydrosurgical and mechanical debridement and a systemic antifungal treatment prior to re-application of the STSGs. The subsequent skin transplant was successful.

6.
Front Bioeng Biotechnol ; 9: 649317, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33937217

RESUMO

Background: Toxic epidermal necrolysis (TEN) is a rare life-threatening disease that mainly affects the skin and mucous membranes, resulting from a toxic delayed-type hypersensitivity (DTH) reaction (type IV reaction) to the presence of foreign antigens such as drugs. The clinical symptoms are caused by pathophysiological processes leading to massive apoptosis of keratinocytes in the dermo-epidermal junction. This results in the formation of a bulla and subsequent separation of the entire epidermis with the exposure of the dermis. The current approach in the local therapy of TEN prefers the use of biological dressings, which helps provide several critical requirements for defect healing; in particular, it helps in the acceleration of the spontaneous wound closure (re-epithelialization) of the skin defect and the reduction of the risk of development of various complications and infections, such as the risk of pathological scar maturation. This paper is a case report of the use of a lyophilized amniotic membrane (AM) for accelerating wound healing in a patient with TEN. Case Presentation: We report a case of an 8-year-old girl transferred to our center with a histologically confirmed diagnosis of TEN. Despite the application of immunosuppressive therapy consisting of corticosteroids and intravenous immunoglobulins, we have observed disease progression and exfoliation of up to 60% of the total body surface area (TBSA). In the facial area, which is cosmetically privileged, we decided to use the lyophilized amniotic membrane (Amnioderm®) to cover up approximately 2% of the TBSA. Within 2 days after the application, we observed accelerated reepithelialisation, with rapid wound closure. We have not observed any side effects nor infections during the subsequent phases of wound healing. Skin defects in non-facial areas of the body were treated with synthetic dressings. When compared to the areas covered with the lyophilized AM, the healing process was prolonged. Conclusions: To our knowledge, this is the first case study using a lyophilized amniotic membrane in the treatment of a patient with TEN. The AM application in the cosmetically-privileged area (face), proved to be very efficient in the treatment of TEN patients. The use of this allogeneic material demonstrated excellent biocompatibility and caused a unique acceleration of epithelialization and wound healing, yielding also excellent long-term results. The current study opens broad possibilities for clinical application of the used material, the improvement of current therapy of patients with TEN and better outcomes and recovery of patients.

7.
Phys Chem Chem Phys ; 21(11): 6178-6185, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30821802

RESUMO

Using density functional theory including van der Waals interactions, we calculate the adsorption and electronic properties of dithiol-dicarba-closo-dodecaboranes chemisorbed on Au(111) surfaces. Carborane molecules consist of a cage-like structure made of boron and carbon atoms and possess a large intrinsic dipole. We consider two functionalized carborane positional isomers, with thiol linker groups attached to either carbon or boron backbone atoms, such that when adsorbed on the Au substrate, the molecular dipole points towards the metal surface or away from it. We investigate a large number of junction geometries and find that carborane adsorption can induce significant changes in the work function of the Au substrate, in the range of 1 eV. These changes depend strongly on the interface geometry at the atomistic level. From the analysis of these junction structures, we provide a picture of the driving mechanisms that determine adsorption geometries, and relate them to interface electronic structure and resulting work function modification. In particular, our results highlight the important role played in these interface quantities by distortions in the Au surface layer induced by carborane adsorption.

8.
J Colloid Interface Sci ; 512: 308-317, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29078182

RESUMO

Multimodal probes, which can be simultaneously visualized by multiple imaging modalities, enable the cellular uptake, intracellular fate, biodistribution and elimination to be tracked in organisms. In this study, we report the synthesis of crystalline WO3 and CaWO4 doped with Eu3+ or Tb3+ nanoparticles (size range of 10-160 nm) coated with polysaccharides, and these nanoparticles constitute a versatile easy-to-construct modular toolbox for multimodal imaging. The particles adsorb significant amounts of polysaccharides from the solution, providing biocompatibility and may serve as a platform for labeling. For WO3, the sorption is reversible. However, on CaWO4, stable coating is formed. CaWO4/Tb3+ coated with chemisorbed dextrin, mannan, guar gum and sodium alginate successfully underwent endocytosis with HepG2 cells and was visualized using confocal microscopy.


Assuntos
Materiais Biocompatíveis/química , Endocitose/fisiologia , Luminescência , Nanopartículas/administração & dosagem , Polissacarídeos/química , Tungstênio/química , Células Hep G2 , Humanos , Microscopia Confocal , Nanopartículas/química , Nanopartículas/efeitos da radiação , Térbio/química
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