RESUMO
Burns are one of the most common traumatic injuries in the world, representing a global public health problem. Major burns (severe burn injury or burn disease) are one of the most life-threatening injuries. There is a great need to identify and monitor the development of complications (sepsis and septic shock, coagulopathy and DIC) in burned patients. The basis of the pathogenesis of burn injury, as well as any general pathological process, is an inflammatory reaction, ultimately aimed at restoring the structure and function of the damaged tissue. A feature of the inflammatory reaction in burn injury is the scale of alteration of the skin and mucous membranes. The review presents the main aspects of the burn injuries immunopathogenesis and the features of post-burn immune dysfunction, manifested by disorders in the innate and adaptive immunity systems. Attention is focused on the role in the immunopathogenesis of developing systemic and local disorders in burn injury. Also the role are discussed of a minor subpopulations of lymphocytes (Treg-, Th-17-, γδT-cells) in the immunopathogenesis and in the bacterial infection protection. The characteristics of the main immuno-biochemical markers of burn injury (cytokines and growth factors, nitric oxide, matrix metalloproteases, bacteria concentration levels) are present. The prognostic role of these biomarkers in assessing of the severity degree of patients with burn injury and wound healing processes is shown. The review has been compiled using references from major databases such as RSCI, Web of Science, PubMed, Scopus and Google Scholar (up to march 2022). After obtaining all reports from database, the papers were carefully analyzed in order to find data related to the topic of this review (60 references).
Assuntos
Sepse , Cicatrização , Biomarcadores , Citocinas , Humanos , Inflamação , PrognósticoRESUMO
Adjuvant activity of fucoidans in experimental vaccine compositions with ovalbumin was studied on a mouse model. Compositions with sulfated polysaccharides from brown alga Fucus evanescens (native fucoidan in combination with polyphenols, and a product of fucoidan enzymatic hydrolysis) induced multiple productions of antigen-specific antibodies - total IgG, its isotypes IgG1 and, especially, IgG2a, in comparison with an individual ovalbumin. The adjuvant effect of native and structurally modified fucoidans is slightly inferior to that of the traditional licensed aluminum hydroxide adjuvant. The results indicate the prospects of using sulfated polysaccharides from F. evanescens as adjuvants in vaccines.
Assuntos
Imunidade Humoral/efeitos dos fármacos , Ovalbumina/imunologia , Polissacarídeos/farmacologia , Animais , Fucus/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
The effect of sulfated polysaccharide from brown alga Fucus evanescens (fucoidan) administered via different routes (peroral and parenteral) on the dynamic of some lipid metabolism parameters and markers of systemic inflammation in mice with experimental dyslipidemia induced by prolonged administration of poloxamer P-407. It was found that fucoidan corrected the main parameters of lipid metabolism, reduced the level of endothelial dysfunction marker endothelin-1 and proinflammatory cytokines TNFα, IFNγ in blood serum in animals with experimental dyslipidemia. These findings open prospects for using fucoidan in the complex treatment of metabolic disorders and atherosclerotic inflammation.
Assuntos
Anti-Inflamatórios/farmacologia , Dislipidemias/tratamento farmacológico , Fucus/química , Regulação da Expressão Gênica/efeitos dos fármacos , Polissacarídeos/farmacologia , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , HDL-Colesterol/sangue , LDL-Colesterol/sangue , VLDL-Colesterol/sangue , Dislipidemias/induzido quimicamente , Dislipidemias/genética , Dislipidemias/imunologia , Endotelina-1/genética , Endotelina-1/imunologia , Inflamação/prevenção & controle , Interferon gama/genética , Interferon gama/imunologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Poloxâmero/administração & dosagem , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Triglicerídeos/sangue , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
The data on the experimental study of the efficacy of the gel wound dressings based on chitosan and calcium alginate containing bioactive substances from marine hydrobionts with complex therapeutic action (sulfated polysaccharides from brown algae, hydrolyzed bivalves, peptides from nerve ganglia of cephalopods) are described. The model of thermal burns complicated by Staphylococcus aureus infection was used. Planimetric and bacteriological investigations revealed pronounced wound healing and antibacterial effects of the gel coating. The gel containing sulfated polysaccharides from brown algae showed the highest wound healing activity.
Assuntos
Antibacterianos/farmacologia , Queimaduras/tratamento farmacológico , Peptídeos/farmacologia , Polissacarídeos/farmacologia , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Alginatos/química , Animais , Antibacterianos/isolamento & purificação , Bandagens , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Bivalves/química , Queimaduras/complicações , Queimaduras/microbiologia , Queimaduras/mortalidade , Cefalópodes/química , Quitosana/química , Gânglios/química , Géis , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Masculino , Camundongos , Peptídeos/isolamento & purificação , Phaeophyceae/química , Polissacarídeos/isolamento & purificação , Pele/efeitos dos fármacos , Pele/lesões , Pele/microbiologia , Infecções Cutâneas Estafilocócicas/complicações , Infecções Cutâneas Estafilocócicas/microbiologia , Infecções Cutâneas Estafilocócicas/mortalidade , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Análise de Sobrevida , Cicatrização/fisiologiaRESUMO
The effect of sulfated polysaccharides (PS) from brown alga Fucus evanescens and their enzymatic transformation and low molecular weight product on the functional activity of the innate immunity cells, i.e. polymorphonuclear leukocytes of human peripheral blood (NF) was comparatively studied. The in vitro NF contact with PS resulted in significant changes in the functional activity of NF, evident from higher density of molecules CD69, CD14, CD11b on the cell membranes with simultaneous lowering of that of CD62L and increased phagocytic and bactericidal activity of NF. The low molecular weight product resulting from fucoidan transformation with fucoidanases showed a higher effect on the level of the molecules CD14, CD11b and CD62L expression vs. the high molecular weight PS.
Assuntos
Fucus/química , Regulação da Expressão Gênica/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Polissacarídeos/farmacologia , Antígenos CD/genética , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/genética , Antígenos de Diferenciação de Linfócitos T/imunologia , Antígeno CD11c/genética , Antígeno CD11c/imunologia , Glicosídeo Hidrolases/química , Humanos , Hidrólise , Selectina L/genética , Selectina L/imunologia , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/imunologia , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/imunologia , Fagocitose/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Cultura Primária de Células , Sulfatos/químicaRESUMO
In the review there are considered the recent data on the perspectives of the use of polysaccharides (PS) from marine hydrobionts for nhibition of formation of bacterial biofilms, which play a significant role in the onset and process of different infections, as well as for design of antiadhesive coatings on medical produce. Particular attention is paid to antiadhesive properties of natural PS from marine microorganisms, algae and invertebrate animals, which prevent formation of biofilms. Antibiofilm PS possess such positive characteristics, as biocompatibility and biodegradability, that is of great interest for medical and industrial applications. The possibility of simultaneous use of complexes of compounds of different chemical nature and mechanisms of action in infectious diseases, involving biofilm formation is of special interest. It is believed that biologically active substances from marine hydrobionts could serve as the basis for development of new antibiofilm drugs, including complex ones.
RESUMO
Under the conditions of emergence of microbial strains with new properties, including antibiotic resistance, in human and animal populations the search for new antimicrobial substances with improved pharmacological properties and new mechanisms of action from natural objects, in particular from aquatic organisms, is continued. This review presents extensive data on antibacterial, antiviral and antifungal properties of biologically active substances (BAS) of different chemical nature, recovered from representatives of the class of cephalopods (squid, octopus, cuttlefish, nautilus). Analysis of the literature shows that antibacterial activity of some BAS is not inferior, but in some cases is even superior to that of the available antibiotics. The authors note that the review includes the results, mainly of the in vitro studies. Adequate extrapolation of these data to the in vivo conditions is required, that could serve as foundation for development of new generations of medicinal compounds, functional foods and biologically active food supplements.
Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Cefalópodes/química , Animais , HumanosRESUMO
We studied the influence of fucoidans from brown algae Fucus evanescens, Laminaria cichorioides and Laminaria japonica on apoptosis of human peripheral blood lymphocytes. It was demonstrated that fucoidans induced lymphocyte apoptosis, increased the proportion of cells with low mitochondrial transmembrane potential, and inhibit expression of Bcl-xL gene in blood lymphocytes. These findings suggest that lymphocyte apoptosis induced by the analyzed sulfated polysaccharides is mediated by mitochondrial pathway.
Assuntos
Fucus/química , Laminaria/química , Leucócitos Mononucleares/efeitos dos fármacos , Phaeophyceae/química , Polissacarídeos/farmacologia , Proteína bcl-X/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Apoptose/genética , Expressão Gênica/efeitos dos fármacos , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Polissacarídeos/isolamento & purificação , Cultura Primária de Células , Sulfatos , Proteína bcl-X/genética , Proteína bcl-X/metabolismoRESUMO
We have studied the distribution of plant fibers of different sizes in the digestive tracts of two hare species: the brown hare (Lepus euopaeus) and the mountain hare (L. timidus). In all studied hares (18 specimens), the highest amount of fine-sized fibers (less than 0.25 mm length) was observed in the cecum (50-70% of the total fiber mass). It was found out that the fine-sized content in the digestive tract, and especially in the cecum, is provided not only by the separation mechanism of the colon, but also by coprophagy. It was shown that repeated passage of food through the digestive tract compensates small volume of the cecum and increases the period of digestion of the same portions of food.
Assuntos
Ceco/metabolismo , Colo/metabolismo , Coprofagia/fisiologia , Fibras na Dieta/metabolismo , Lebres/fisiologia , Animais , Ceco/anatomia & histologia , Colo/anatomia & histologia , Lebres/anatomia & histologiaRESUMO
The biological activity of ethyl acetate extract of exometabolites from the marine microalgae Phaeodactylum tricornutum against a test culture of Listeria monocytogenes 4b has been investigated. It was shown that the stimulating effect of algal exometabolites on the growth of pathogenic bacteria increased maximally by 98.3% on day 6 of the cultivation, if the active substances comprising the culture liquid of P. tricornutum were separated by successive extractions with solvents in order of increasing polarity (hexane, benzene, ethyl acetate), and by 150% on day 3, if the substances from the ethyl acetate extract of exometabolites were separated by column chromatography. It is noted that the fraction of biologically active substances maximally stimulating the growth of L. monocytogenes can be used to prepare an accumulation medium for detecting these patho- genic bacteria in marine environments and hydrobionts.
Assuntos
Listeria monocytogenes/efeitos dos fármacos , Microalgas/química , Reprodução/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/químicaRESUMO
At present the increase of antibiotic resistance in infection agents to antimicrobial drugs requires discovery of new antimicrobial substances with improved pharmacological properties and novel mechanisms of action, to which microorganisms do not develop resistance. Three areas are of interest for the search: recovery of new compounds from natural objects, including aquatic organisms, chemical modification of the known antibiotic molecules, discovery of compounds with antimicrobial activity among some new chemical structures which have no analogues in nature. The review is mainly concerned with discussion of antibacterial, antiviral and antifungal activity of sulfated polysaccharides (fucoidans) and extracts of brown, red and green algae, as well as of antioxidant, antiinflammatory, immunomodulatory and antiendotoxin properties that contribute to their antiinfective action. Such an activity makes fucoidans promising as a basis for developing new drugs for therapy of infectious diseases.
Assuntos
Antibacterianos/farmacologia , Phaeophyceae/química , Polissacarídeos/farmacologia , Alga Marinha/química , Antibacterianos/isolamento & purificação , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/farmacologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Antivirais/isolamento & purificação , Antivirais/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Clorófitas/química , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/farmacologia , Polissacarídeos/isolamento & purificação , Rodófitas/químicaRESUMO
The article represents the results of studying the effect of a new fermented product (FP) containing the probiotic strain Bifidobacterium bifidum 791 and Biogel from brown algae Laminariajaponica on the composition of intestinal microflora and parameters of innate immunity in mice with experimental dysbacteriosis, induced by administration of gentamicin in dose of 25 mg per kg body weight during 7 days. The experimental animals received for 6 weeks in addition to the diet FP, which was 2% of the average volume of feed intake. The FP influence was manifested by more rapid reduction of dyspepsia symptoms, restoration of body weight and balance the intestinal microbiocenosis (increasing of bifido- and lactobacteria, typical E. coli, reducing of the bacteria genus Proteus and Clostridium, elimination of S. aureus). As the results of FP administration we observed the statistically significant reduction of endogenous intoxication values and increasing of the phagocyte activity of neutrophils, related to effector cells of innate immunity, compared with animals not receiving FP. Identified effects of FP are due to both its probiotic properties through the presence of bifidobacteria and immunomodulating and enteral sorbtion activities of alginate component.
Assuntos
Bifidobacterium/crescimento & desenvolvimento , Disbiose/tratamento farmacológico , Imunidade Inata/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Phaeophyceae/química , Probióticos/uso terapêutico , Animais , Modelos Animais de Doenças , Disbiose/induzido quimicamente , Disbiose/imunologia , Disbiose/microbiologia , Géis , Gentamicinas/efeitos adversos , Intestinos/microbiologia , Camundongos , Probióticos/administração & dosagemRESUMO
We studied the effect of biologically active substances derived from hydrobionts, namely maristim (natural product from sea urchin roe) and fucolam (polysaccharides of fucoidan and calcium alginate from brown algae) on blood biochemistry in the mouse model of nutritional hypercholesterolemia. Maristim and fucolam are found to be capable to normalize the levels of the major indicators of lipid and carbohydrate metabolism and aminotransferase enzyme activity in terms of atherogenic load. Correction action of biologically active substances is more expressed in combined application. Identified experimentally normalizing effects of maristim and on lipid and carbohydrate metabolism allow us to recommend the further study in clinical trials of these biologically active substances and based on them additives.
Assuntos
Produtos Biológicos/farmacologia , Metabolismo dos Carboidratos/efeitos dos fármacos , Misturas Complexas/farmacologia , Hipercolesterolemia/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Polissacarídeos/farmacologia , Alginatos/farmacologia , Animais , Análise Química do Sangue , Metabolismo dos Carboidratos/fisiologia , Dieta Aterogênica , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/farmacologia , Hipercolesterolemia/etiologia , Metabolismo dos Lipídeos/fisiologia , Camundongos , Oceano Pacífico , Phaeophyceae/química , Ouriços-do-Mar/química , Transaminases/metabolismoRESUMO
The effects of triterpene glycosides (saponins) extracted from Saponaria officinalis L. radices, on the cellular and humoral innate immunity factors were studied. Saponins stimulated the phagocytic, bactericidal, and adhesion activities of polymorphonuclear leukocytes. Optimal conditions of saponin treatment (dose and duration) were determined for mice. Saponins promoted the maturation of human peripheral blood dendritic cells, which was proven by high expression of CD83 (terminal differentiation marker) and CD86 (bone-stimulating molecule) and of HLA-DR and HLA-ABC molecules on the cell membrane. Saponins modulated the production of TNF-α, IL-1ß, IL-4, IL-6, and IFN-γ in cultured peripheral blood intact cells. The results help to understand some mechanisms of the effects of saponins extracted from Saponaria officinalis L. radix on the cellular and humoral factors of innate immunity and demonstrate good prospects of their practical use.
Assuntos
Imunidade Inata/efeitos dos fármacos , Extratos Vegetais/farmacologia , Saponaria/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Células Cultivadas , Glicosídeos/química , Humanos , Camundongos , Triterpenos/químicaRESUMO
Antioxidants of natural origin are considered as possible agents for prevention and treatment of liver diseases. Marine algae and in particular their extracts and obtained from them sulfated polysaccharides are significant sources of natural antioxidants. The recent data on the effect of the extracts and sulfated polysaccharides of seaweed on the functional activity of the liver with injuries induced by CCl4, some drugs (paracetamol, diclofenac), N-nitrosocompounds, aflatoxin are presented in the review. Particular attention is paid to the effect of sulfated polysaccharides and in particular fucoidans on the functional activity of the liver in patients with chronic viral hepatitis C. Fucoidan is highly safe and active not only as an antioxidant but also as an inhibitor of HCV replication, has antiinflammatory and immunomodulating effects. The data of the review allow to conclude that seaweed extracts and sulfated polysaccharides may be a basis for development of new generation drugs in the future for the treatment and prevention of liver diseases.
Assuntos
Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Fatores Imunológicos/farmacologia , Polissacarídeos/farmacologia , Alga Marinha/química , Acetaminofen , Aflatoxinas , Animais , Antioxidantes/isolamento & purificação , Tetracloreto de Carbono , Diclofenaco , Hepatite C Crônica/virologia , Humanos , Fatores Imunológicos/isolamento & purificação , Compostos Nitrosos , Polissacarídeos/isolamento & purificaçãoRESUMO
In order to assess the role of the microbiocenosis of the digestive tract of herbivorous birds in transforming poor forage, the activity of cellulolytic enzymes in all departments of the gastrointestinal tract of the black grouse (Lyrurus tetrix) and Western capercaillie (Tetrao urogallus) was studied. The functional diversity of microbial communities of different departments was also investigated. In both species of birds, nitrogenase and cellobiohydrolase activities were discovered in the digestive tract, with the maximum observed in the cecum.
Assuntos
Aves/microbiologia , Sistema Digestório/microbiologia , Trato Gastrointestinal/microbiologia , Microbiota , Animais , Sistema Digestório/enzimologia , Trato Gastrointestinal/enzimologiaRESUMO
The purpose of this study was to assess the performance of Cepheid® Xpert MTB/RIF® ("Xpert") and TB-Biochip® MDR ("TB-Biochip"). Sputum specimens from adults with presumptive tuberculosis (TB) were homogenized and split for: (1) direct Xpert and microscopy, and (2) concentration for Xpert, microscopy, culture [Lowenstein-Jensen (LJ) solid media and Mycobacteria Growth Indicator Tube® (MGIT)], indirect drug susceptibility testing (DST) using the absolute concentration method and MGIT, and TB-Biochip. In total, 109 of 238 (45.8 %) specimens were culture-positive for Mycobacterium tuberculosis complex (MTBC), and, of these, 67 isolates were rifampicin resistant (RIF-R) by phenotypic DST and 64/67 (95.5 %) were isoniazid resistant (INH-R). Compared to culture of the same specimen, a single direct Xpert was more sensitive for detecting MTBC [95.3 %, 95 % confidence interval (CI), 90.0-98.3 %] than direct (59.6 %, 95 % CI, 50.2-68.5 %) or concentrated smear (85.3 %, 95 % CI, 77.7-91.1 %) or LJ culture (80.8 %, 95 % CI, 72.4-87.5 %); the specificity was 86.0 % (95 % CI, 78.9-91.3 %). Compared with MGIT DST, Xpert correctly identified 98.2 % (95 % CI, 91.5-99.9 %) of RIF-R and 95.5 % (95 % CI, 85.8-99.2 %) of RIF-susceptible (RIF-S) specimens. In a subset of 104 specimens, the sensitivity of TB-Biochip for MTBC detection compared to culture was 97.3 % (95 % CI, 91.0-99.5 %); the specificity was 78.1 % (95 % CI, 61.5-89.9 %). TB-Biochip correctly identified 100 % (95 % CI, 94.2-100 %) of RIF-R, 94.7 % (95 % CI, 76.7-99.7 %) of RIF-S, 98.2 % (95 % CI, 91.4-99.9 %) of INH-R, and 78.6 % (95 % CI, 52.1-94.2 %) of INH-S specimens compared to MGIT DST. Xpert and Biochip were similar in accuracy for detecting MTBC and RIF resistance compared to conventional culture methods.
Assuntos
Técnicas Bacteriológicas , Testes de Sensibilidade Microbiana , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Adulto , Técnicas Bacteriológicas/métodos , Humanos , Testes de Sensibilidade Microbiana/métodos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Prevalência , Reprodutibilidade dos Testes , Federação Russa/epidemiologia , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologiaRESUMO
UNLABELLED: Inflammatory bowel disease is one of the most difficult groups of pathologies in pediatric gastroenterology, due to the steady growth of their prevalence, offset debut at an earlier age, the increase in the incidence of severe complicated forms. Established clinical, genetic, serologic criteria for progression of ulcerative colitis are contradictory, and some--the reach of most medical institutions. PURPOSE: to evaluate the prognostic significance of morphological features of ulcerative colitis relapse and continuous flow. MATERIALS AND METHODS: a retrospective study conducted histological kolonobioptatov 26 children with recurrent, 20--with a continuous flow of ulcerative colitis during their primary treatment in a hospital, the comparison group consisted of 50 children without inflammatory bowel disease. RESULTS: morphological characteristics identified predictors of recurrent ulcerative colitis in the form of severe eosinophilic infiltration of the epithelium, lamina propria of the mucosa. For a continuous flow was characterized: high density cell infiltration of the lamina propria mucosa epithelium predominantly under represented plasma cells, fibroblasts, sclerosis of the basal membrane, the presence of epithelial arcades deformed crypt abscesses. CONCLUSION: the extended study of biopsy material, including assessment of the composition and location of infiltration, fibroblast pool of epithelial-connective relationships in the colonic mucosa of children with ulcerative colitis will not only assess the inflammatory process, but also to predict the course of disease, thereby defining a long-term tactics treatment.
Assuntos
Colite Ulcerativa/patologia , Colo/patologia , Mucosa Intestinal/patologia , Biópsia , Criança , Progressão da Doença , Seguimentos , Humanos , Prognóstico , Recidiva , Estudos RetrospectivosRESUMO
The properties of amperometric biosensors based on methanol dehydrogenase (MDH), Methylobacterium nodulans cells, and the ferrocene-modified carbon paste electrode were investigated. It was shown that the addition ofhydroxyapatite (HA) to a carbon paste increased the sensitivity and operating stability of MDH biosensors. The linear range of the electrode was 0.0135-0.5 and 0.032-1.5 mM for methanol and formaldehyde, respectively. The detection limit of methanol and formaldehyde was 4.5 and 11.0 microM, respectively. The loss of activity of the electrode within 10 days of storage in the presence of 2.0 mM KCN did not exceed 12%. Cyanide (10 mM) completely inhibited the sensor responses to formaldehyde (1.0 mM), which allowed for the selective determination of methanol in the presence of formaldehyde. The biosensor based on cells exhibited lower stability and sensitivity toward methanol and formaldehyde; the sensitivity coefficients were 980 and 21 nA/mM, respectively.
Assuntos
Oxirredutases do Álcool/química , Proteínas de Bactérias/química , Técnicas Biossensoriais/métodos , Formaldeído/análise , Metanol/análise , Methylobacterium/enzimologia , Carbono/química , Durapatita/químicaRESUMO
The macro- and microstructures of the surface of the mucous membrane of the gastrointestinal tract were studied in detail in two hare species (Lepus europaeus and L. timidus) using scanning electron and digital microscopes. The morphology of the gastrointestinal tract of hares, which is similar in the two species studied, was described in detail. The macrostructure of the inner surface of the ileocecal junction was investigated. The particularities of the architectonics of the mucous membrane of the intestine that are specific for hares were revealed. In the jejunum of both hare species, the mucous membrane is represented by villi with merged bases, which form circular plates. The mucosa of the colon forms large conical villi, the surface of which is scattered with secreting cells. The possible functional significance of the revealed morphological particularities is discussed.