RESUMEN
OBJECTIVE: The objective of the study was to analyze histological changes in the site of the meshes FTOREX, FTOREX coated with carboxymethylcellulose, Ventralight ST, Symbotex, REPEREN-16-2 and decellularized porcine peritoneum on the parietal peritoneum of the pig. MATERIAL AND METHODS: At laparoscopy, 6 different meshes were placed intraperitoneally in each of the 3 pigs. After 90 days, the animals were taken out of the experiment. After staining with hematoxylin and eosin, quantitative morphometry and counting the number of vessels and cells in the interstitium in the areas of the mesh and peritoneum were performed. An immunohistochemical study with an antibody to pancytokeratins assessed the state of the initial peritoneum and neoperitoneum. RESULTS: According to morphological characteristics, the meshes were divided into 3 groups: 1) with fluoropolymer coating FTOREX, 2) Ventralight ST and Symbotex, 3) REPEREN and decellularized peritoneum. In group 1, the surface area of the mesh threads was optimal in terms of the arrangement and arrangement of the threads relative to each other. This contributed to the formation of a relatively dense fibrous framework and a place to preserve the underlying peritoneum involved in the formation of the neoperitoneum. Despite the smallest surface area of the threads, in group 3, the greatest fibroblastic reaction was noted. Inflammatory changes were the least pronounced in group 1. They were the greatest in group 3, where there was a pronounced leukocyte reaction, combined with the processes of metaplasia, the development of fibrinoid necrosis, and the progression of the secondary inflammatory process. In group 1, the optimal ratio of newly formed vessels was noted, in group 2 - veins prevailed over arteries, in group 3 - the number of vessels was minimal. Immunohistochemical study showed that in group 1, mesothelial cells covered almost the entire surface of the implant, and there were also areas of preserved basic peritoneum. In group 2, mesothelium also covered most of the surface of the meshes, but the underlying peritoneum was absent. In group 3, on the contrary, a significant number of extended areas not covered with mesothelium were revealed. CONCLUSION: The conducted morphological and morphometric study showed that the most balanced ratio of the components of the newly formed fibrous tissue and blood vessels is observed when using implants with a fluoropolymer coating FTOREX. At the same time, the remaining basic peritoneum actively participated in the formation of the neoperitoneum. The Ventralight ST and Symbotex meshes also contributed to the formation of a full-fledged fibrous tissue and adequate vascular proliferation, however, they prevented the preservation of the underlying peritoneum, which practically excluded its participation in the formation of the neoperitoneum. The REPEREN mesh and decellularized porcine peritoneum led to the least balanced cell and vascular proliferation and the greatest fibroplastic reaction, which could further negatively affect the state of the formed scar.
Asunto(s)
Polímeros de Fluorocarbono , Laparoscopía , Animales , Porcinos , Mallas Quirúrgicas/efectos adversos , Peritoneo/cirugía , Peritoneo/patología , Laparoscopía/métodos , Prótesis e Implantes , Adherencias Tisulares/etiología , Adherencias Tisulares/prevención & control , Adherencias Tisulares/patología , HerniorrafiaRESUMEN
Treatment of patients with long-term persistent symptoms after COVID-19 is an urgent problem for clinicians around the world. One of the most significant manifestations of post-COVID-19 syndrome is organizing pneumonia that is usually treat with corticosteroids. The paper presents a clinical case of typical course of post-COVID-19 organizing pneumonia in a patient without previous lung disease. Risk factors, diagnostic methods and treatment options in this group of patients are also discuss.
Asunto(s)
COVID-19 , Neumonía , Humanos , COVID-19/diagnóstico , Pulmón/diagnóstico por imagen , Neumonía/diagnóstico , Neumonía/tratamiento farmacológico , Neumonía/etiología , Corticoesteroides/uso terapéuticoRESUMEN
AIM: To determine the incidence and risk factors of acute kidney injury (AKI) in Russian cohort of patients with COVID-19. MATERIALS AND METHODS: We included 315 patients, who were hospitalized with COVID-19 from October 2020 till February 2021. The diagnosis was established on the basis of the positive SARS-CoV-2 swab test and/or typical radiologic findings on CT scans. RESULTS: AKI complicated the clinical course in 92 (29.21%) cases. The independent risk factors of AKI were female sex, underline chronic kidney disease and the highest level of C-reactive protein during hospitalization. In the general group of patients were 41 (13%) lethal cases, in the group with AKI 32 (34.8%). Compared with those without AKI, patients with AKI had 4.065 (95% confidence interval 2.154 to 7.671) times the odds of death. Respiratory support, the highest serum creatinine and glucose levels appeared to be the risk factors of death among patients with AKI in the multivariable Cox regression. CONCLUSION: The clinical course of COVID-19 was complicated by AKI in 29% cases. The independent risk factors of AKI in patients with COVID-19 are underline chronic kidney disease, circulatory disorder and the highest level of C-reactive protein during hospitalization.
Asunto(s)
Lesión Renal Aguda , COVID-19 , Insuficiencia Renal Crónica , Humanos , Femenino , Masculino , COVID-19/complicaciones , COVID-19/epidemiología , SARS-CoV-2 , Creatinina , Proteína C-Reactiva , Estudios Retrospectivos , Factores de Riesgo , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Riñón , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/etiología , Glucosa , Mortalidad HospitalariaRESUMEN
OBJECTIVE: Analysis of development of «robotic surgery¼ on the basis of historical prerequisites, review of the possibilities of the new Senhance robotic surgical system and determination of further perspective. MATERIAL AND METHODS: A prospective group of 51 patients with surgical pathology who underwent surgical interventions using the new Senhance robotic system was analyzed. The study included 51 patients. Robot-assisted cholecystectomy was performed in 20 patients, 31 patients underwent robotic transabdominal preperitoneal plastic surgery. RESULTS: A short-term analysis of intraoperative and early postoperative data showed the safety of using the Senhance robotic complex for the patient. The ergonomics of this system contributes to significantly less fatigue of the surgeon during the operation, increasing its efficiency and safety. CONCLUSION: The emergence of competitive robotic systems contributes to the dynamic development of robotic surgery, which in turn will lead to a reduction in the cost of these technologies in the future. Innovative solutions used in modern robotic complexes are based on the principles of machine learning, which in due time will make the «robot surgeon¼ not just a tool, but a full-fledged member of the operating team.
Asunto(s)
Procedimientos Quirúrgicos Robotizados , Cirujanos , Humanos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Colecistectomía/efectos adversosRESUMEN
Leishmaniasis is a vector-born parasitic disease characterized by predominant cutaneous or visceral involvement with fever, hepatosplenomegaly and anemia. Leishmaniasis has relatively high prevalence in tropical and subtropical areas. Several sporadic and mostly imported cases are detected in Russian Federation. Nevertheless, some local incidents are noted in southern areas (Crimea, Dagestan). Lack of epidemiological alertness hampers confirmation of diagnosis and may lead to incorrect treatment. The article summarizes current state of knowledge in epidemiology, diagnostic approach and treatment of leishmaniasis. Particular clinical case is discussed.
Asunto(s)
Anemia , Leishmaniasis Visceral , Humanos , Medicina Interna , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/epidemiología , Federación de Rusia/epidemiología , EsplenomegaliaRESUMEN
AIM: In a retrospective study, we evaluated factors associated with the early development of septic shock in patients with severe COVID-19. MATERIALS AND METHODS: We collected medical records of the intensive care unit patients submitted by the local COVID-19 hospitals across Russia to the Federal Center for the Critical Care at the Sechenov First Moscow State Medical University (Sechenov University). Septic shock in crticially ill patients requiring mechanical ventilation was defined as a need in vasopressors to maintain blood pressure. RESULTS: We studied 1078 patients with severe COVID-19 who were admitted to the intensive care units for respiratory support. There were 611 males and 467 females. The mean age was 61.013.7 years. Five hundred twenty five medical records (48.7%) were received from the Moscow hospitals, 159 (14.7%) from the Moscow region, and 394 (36.5%) from the hospitals located in 58 regions of the Russian Federation. In 613 (56.9%) patients, diagnosis of SARS-CoV-2 infection was confirmed by PCR, and in the other cases it was established on the basis of the clinical picture and the results of the chest CT scan. Septic shock developed in 214 (19.9%) of 1078 patients. In the logistic regression model, the risk of septic shock in patients older than 50 years was higher than in patients of a younger age (OR 2.34; 95% CI 1.533.67; p0.0001). In patients with more severe SARS-CoV-2 infection, there was an increase in the prevalence of cardiovascular diseases, including coronary heart disease and atrial fibrillation, type 2 diabetes and malignant tumors. The risk of septic shock in patients with three or more concomitant diseases was higher than in patients without any concomitant chronic diseases (OR 1.76; 95% CI 1.762.70). CONCLUSION: The risk of septic shock in patients with acute respiratory distress syndrome induced by SARS-CoV-2 is higher in patients older than 50 years with concomitant diseases, although a severe course of the disease is also possible in younger patients without any concomitant disorders.
Asunto(s)
COVID-19 , Diabetes Mellitus Tipo 2 , Choque Séptico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Moscú/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Federación de Rusia/epidemiología , SARS-CoV-2 , Choque Séptico/diagnóstico , Choque Séptico/epidemiología , Choque Séptico/etiologíaRESUMEN
The objective of this study was to determine the impact of polymorphism of CYP3A subfamily isoenzymes (allelic variants of CYP3A4*22 and CYP3A5*3) on the efficacy clopidogrel in patients with an acute coronary syndrome (ACS), who have undergone percutaneous coronary intervention (PCI). Platelet activity was determined on a VerifyNow P2Y12 test system in 81 patients with ACS aged 37-91 who had PCI. The activity of CYP3A4/5 was expressed as the ratio of the concentrations of cortisol and 6ß-hydroxycortisol was performed by using high performance liquid chromatography. Genotyping was performed by using real-time polymerase real-time chain reaction. The frequencies for the CYP3A5 gene, rs 776746, were identified as follows: 77 (95.1%)-CC, 4 (4.9%)-CT; the allele frequencies by loci for the CYP3A4, rs rs35599367, were as follows: 78 (96.3%)-GG, 3 (3.7%)-AG. There was no statistically significant genotype-dependent difference between the presence of a minor T and G alleles and the presence of clopidogrel resistance (OR 3.53; 95% CI 0.46-26.94; p = 0.233 and p = 0.443, respectively). The average level of the metabolic relationship (6ß-hydroxycortisol/cortisol) between the clopidogrel-resistant group and the normal platelet reactivity group was not statistically significantly different: 3.3 ± 2.8 versus 3.2 ± 3.2; p = 0.947. So, the activity of CYP3A4/5 was not related to platelet aggregation rates in this model. Genotyping and phenotyping CYP3A4\CYP3A5 does not predict the antiplatelet effect of clopidogrel. More extensive research is required to establish their clinical relevance.
Asunto(s)
Síndrome Coronario Agudo/genética , Citocromo P-450 CYP3A/genética , Síndrome Coronario Agudo/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Biomarcadores Farmacológicos , Plaquetas/metabolismo , Clopidogrel/farmacología , Enfermedad de la Arteria Coronaria/genética , Citocromo P-450 CYP3A/metabolismo , Femenino , Frecuencia de los Genes/genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Agregación Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/genética , Inhibidores de Agregación Plaquetaria/metabolismo , Inhibidores de Agregación Plaquetaria/farmacología , Polimorfismo Genético/genéticaRESUMEN
Analysed herein are the data of 737 patients (a total of 745 lower limbs) suffering from lower-limb varicose veins (LLVV) and subjected to treatment at the Surgical Department consisting of crossectomy, truncal and tributary phlebectomy, dissection of perforant veins exclusively in the basin of the great saphenous vein. Relapses during five-year follow up occurred in 13.8% (102/745) of cases. Based on clinical signs and laboratory findings we studied the effect of the factor of undifferentiated connective tissue dysplasia (UDCTD) on the development of lower-limb varicosity. We carried out comparative analysis in the groups with relapsing LLVV (n=43), without relapses (n=39) and control group comprising volunteers not suffering from LLVV (n=37). The median of blood serum total oxiprolin concentration in LLVV patients both with and without relapses was elevated and amounted to 18.4 (IR 14.9-19.65) and 14.3 (IR 13.1-16.5) versus 8.35 (5.75-9.75) µmol/l, respectively. The mode of the clinical parameter of UDCTD degree in accordance with the rating scale of Smolnova T.Yu. (2003) in the group of patients with LLVV relapses turned out to be higher (Mo=19) than in the group of patients without relapses (Mo=10, p=0.003). The lowest score was in the control group. In patients having immediate relatives with LLVV the level of blood serum total oxiprolin and clinical scores of LLVV turned out to be statistically significantly higher. Hence, based on the obtained during the study clinical and laboratory findings it may be supposed that undifferentiated connective tissue dysplasia plays an important part in the development of both lower limb varicosity and relapses thereof.
Asunto(s)
Enfermedades del Tejido Conjuntivo/complicaciones , Vena Safena/cirugía , Várices , Procedimientos Quirúrgicos Vasculares , Enfermedad Crónica , Enfermedades del Tejido Conjuntivo/diagnóstico , Enfermedades del Tejido Conjuntivo/metabolismo , Femenino , Humanos , Hidroxiprolina/metabolismo , Extremidad Inferior/irrigación sanguínea , Masculino , Persona de Mediana Edad , Recurrencia , Vena Safena/patología , Estadística como Asunto , Várices/diagnóstico , Várices/etiología , Várices/fisiopatología , Várices/cirugía , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/métodosRESUMEN
Research on thermoelectric (TE) materials has been focused on their transport properties in order to maximize their overall performance. Mechanical properties, which are crucial for system reliability, are often overlooked. The recent development of a new class of high-performance, low-dimension thermoelectric materials calls for a better understanding of their mechanical behavior to achieve the desired system reliability. In the present study we investigate the mechanical behavior of nanostructure bulk TE material p-type Bi(x)Sb(2-x)Te(3) by means of nanoindentation and 3D finite element analysis. The Young's modulus of the material was estimated by the Oliver-Pharr (OP) method and by means of numerically assisted nanoindentation analysis yielding comparable values about 40 GPa. Enhanced hardness and yield strength can be predicted for this nanostructured material. Microstructure is studied and correlation with mechanical properties is discussed.
RESUMEN
Determination of respiratory rate is a necessary task in assessing the state of health in humans. This review provides a description of modern devices used for recording and monitoring respiratory rate. The advantages and disadvantages of the principles of operation of these devices are discussed.
RESUMEN
The concentrations of urea and uric acid increased, while the content of free amino acids decreased in blood serum from rats with alloxan-induced diabetes during acute alcohol intoxication. Activities of glutamate dehydrogenase, AMP deaminase, and tyrosine aminotransferase in the liver of experimental animals increased.
Asunto(s)
Intoxicación Alcohólica/sangre , Aminoácidos/sangre , Nitrógeno de la Urea Sanguínea , Diabetes Mellitus Experimental/sangre , Ácido Úrico/sangre , Intoxicación Alcohólica/complicaciones , Aloxano , Aminohidrolasas/metabolismo , Animales , Depresores del Sistema Nervioso Central/farmacología , Diabetes Mellitus Experimental/complicaciones , Etanol/farmacología , Glutamato Deshidrogenasa/metabolismo , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Ratas , Transaminasas/metabolismoRESUMEN
Valence EELS combined with STEM provides an approach to determine the dielectric constant of materials in the optical range of frequencies. The paper describes the experimental procedure and discusses the critical aspects of valence electron energy-loss spectroscopy (VEELS) treatment. In particular, the relativistic losses might affect strongly the results, and therefore they have to be subtracted from the spectra prior the analysis. The normalization of the energy-loss function is performed assuming an uniform thickness of the investigated area, which is reasonably fulfilled for carefully prepared FIB samples. This procedure requires the presence of at least one reference material with known dielectric properties to determine the absolute thickness. Examples of measuring the dielectric constant for several materials and structures are presented.
RESUMEN
Repeated severe insulin-induced hypoglycemia in rats has led to an increase in aminotransferase, glutaminase, and glutamate dehydrogenase activities in the liver; protease activities in tissues; and in blood serum levels of free fatty acids, urea, and uric acid. These changes are indicative of gluconeogenesis activation in animals exposed to hyperinsulinization. Decreased rates of glycolysis and glycogenolysis, reduced activities of NADP-dependent dehydrogenases, and substantial changes in the activities of enzymes responsible for metabolism of nucleotides and transmitter amino acids have been observed in the brain. All these changes are mainly associated with hypoglycemia and activation of the contrainsular system and can play a significant role in pathogenesis of posthypoglycemic encephalopathy.
Asunto(s)
Metabolismo Energético/efectos de los fármacos , Hipoglucemia/sangre , Hipoglucemiantes/efectos adversos , Insulina/efectos adversos , Aminoácidos/metabolismo , Animales , Encefalopatías Metabólicas/sangre , Encefalopatías Metabólicas/etiología , Ácidos Grasos/sangre , Glucógeno/metabolismo , Glucólisis/efectos de los fármacos , Hipoglucemia/inducido químicamente , Hipoglucemia/complicaciones , Hipoglucemiantes/farmacología , Insulina/farmacología , Hígado/enzimología , Masculino , Neurotransmisores/metabolismo , Nucleótidos/metabolismo , Ratas , Urea/sangre , Ácido Úrico/sangreRESUMEN
Plasmonic nanostructures and -devices are rapidly transforming light manipulation technology by allowing to modify and enhance optical fields on sub-wavelength scales. Advances in this field rely heavily on the development of new characterization methods for the fundamental nanoscale interactions. However, the direct and quantitative mapping of transient electric and magnetic fields characterizing the plasmonic coupling has been proven elusive to date. Here we demonstrate how to directly measure the inelastic momentum transfer of surface plasmon modes via the energy-loss filtered deflection of a focused electron beam in a transmission electron microscope. By scanning the beam over the sample we obtain a spatially and spectrally resolved deflection map and we further show how this deflection is related quantitatively to the spectral component of the induced electric and magnetic fields pertaining to the mode. In some regards this technique is an extension to the established differential phase contrast into the dynamic regime.
RESUMEN
Using a combination of electron holography and energy filtering, interference fringes produced after inelastic interaction of electrons with hydrogen molecules are examined. Surprisingly, the coherence of inelastic scattering increases when moving from the surface of a hydrogen-containing bubble to the vacuum. This phenomenon can be understood in terms of the Feynman two-slit thought experiment with a variable ambiguity of the which-way registration.
RESUMEN
Using the combination of an electron biprism and an energy filter, the coherence distribution in an inelastically scattered wave-field is measured. It is found that the degree of coherence decreases rapidly with increasing distance between two superimposed points in the object, and with increasing energy-loss. In a Si sample, coherence of plasmon scattering increases in vacuum with the distance from the edge of the sample.
RESUMEN
A theoretical framework is described to understand the results of plasmon holography experiments leading to insight in the meaning of the experimental results and pointing out directions for future experiments. The framework is based on the formalism of mutual intensity to describe how coherence is transferred through an optical system. For the inelastic interaction with the object, an expression for the volume plasmon excitations in a free electron gas is used as a model for the behaviour of aluminium. The formalism leads to a clear graphical intuitive tool for understanding the experiments. It becomes evident that the measured coherence is solely related to the angular distribution of the plasmon scattering in the case of bulk plasmons. After describing the framework, the special case of coherence outside a spherical particle is treated and the seemingly controversial idea of a plasmon with a limited coherence length obtained from experiments is clarified.
Asunto(s)
Holografía/métodos , Interpretación de Imagen Asistida por Computador/métodos , Modelos Teóricos , Óptica y Fotónica , Microscopía ElectrónicaRESUMEN
Measurements of absolute positions of electron energy loss spectroscopy (EELS) core-loss edges in a transmission electron microscopy (TEM) are hampered by noticeable errors caused by instabilities of the primary energy of the incident electrons. These instabilities originate from a continuous drift and random ripple of the high tension and are unavoidable in the present generation of TEM and scanning TEM microscopes. However, more precise measurements are desired, for instance, to study the shift of the edge onset between atoms of different valency or chemical environment, the so-called chemical shift. A solution to this problem is presented by collecting a series of short low-loss acquisitions immediately followed by core-loss ones. To ensure a minimal time lapse between core-loss and low-loss acquisitions, all operations must be computer controlled. Accumulation of a number of acquisitions and their summation corrected for energy drift allows to cancel the energy instabilities and to relate the core-loss EELS spectra to the absolute energy scale. A practical algorithm is presented as well as the necessary calibrations for such a procedure. Also, examples of spectra collected using this principle and the resulting measured chemical shifts in several metal-oxides are presented.
RESUMEN
Experiments in 49 albino rats indicated that serum beta-lipoprotein levels were increased on days 1 to 8 and 24 to 29 of readaptation following 30-day restriction of motor activity of the animals kept in the individual cramped cages. The alpha-lipoprotein concentrations were decreased in initial periods and elevated on days 18 to 23 of restoration. In the course of readaptation, the aortic endothelial layer showed greater lymphocyte and monocyte counts and larger number of endotheliocytes with karyopyknosis, karyolysis, and larger number of mitotically divided and binuclear cells. The extent of endotheliocytes and their cytoplasm and nucleus was persistently lower on day 3 to 55 of readaptation.
Asunto(s)
Aorta Abdominal/patología , Aorta Torácica/patología , Lipoproteínas HDL/sangre , Lipoproteínas LDL/sangre , Estrés Psicológico/patología , Adaptación Psicológica , Animales , Recuento de Células , División Celular/fisiología , Endotelio Vascular/patología , Técnicas In Vitro , Ratas , Restricción Física , Estrés Psicológico/sangre , Estrés Psicológico/etiología , Factores de TiempoRESUMEN
Phenylhydrazine was shown to reduce the content of erythroblast islands (EI) within 24 hrs in the rat bone marrow, the effect depending on the dose. Simultaneous strengthening of phagocytic activity, acidifying of lysosomes central macrophages EI and lowering of electrophoretic mobility, were observed. The proteinase inhibitor contrycal (50 and 500 i. u.) prevented the effect in the EI and intensified the regeneration of erythron. In vitro, trypsin and chymotrypsin decreased the EI content in the marrow cell suspension. Changing of functional condition of the central macrophages EI and, probably, products of its secretion, seems to affect the cell complementing in EI.