RESUMO
Non-typhoidal Salmonella (NTS) infections pose a serious public health problem. In addition to the typical course of salmonellosis, an infection with Salmonella bacteria can often lead to parenteral infections and sepsis, which are particularly dangerous for children, the elderly and immunocompromised. Bacterial resistance to serum is a key virulence factor for the development of systemic infections. Salmonella, as an enterobacterial pathogen, has developed several mechanisms to escape and block the antibacterial effects of the complement system. In this review, we discuss the relevance of outer membrane polysaccharides to the complement evasion mechanisms of NTS strains. These include the influence of the overall length and density of the lipopolysaccharide molecules, modifications of the O-antigen lipopolysaccharide composition and the role of capsular polysaccharides in opsonization and protection of the outer membrane from the lytic action of complement. Additionally, we discuss specific outer membrane protein complement evasion mechanisms, such as recruitment of complement regulatory proteins, blocking assembly of late complement components to form the membrane attack complex and the proteolytic cleavage of complement proteins.
Assuntos
Lipopolissacarídeos , Antígenos O , Idoso , Antibacterianos , Proteínas da Membrana Bacteriana Externa , Criança , Complexo de Ataque à Membrana do Sistema Complemento , Proteínas do Sistema Complemento , Humanos , Proteínas de Membrana , Salmonella , Fatores de VirulênciaRESUMO
BACKGROUND: Interim PET after two ABVD cycles (iPET2) predicts treatment outcome in classical Hodgkin's lymphoma. To test whether an earlier assessment of chemosensitivity would improve the prediction accuracy, we launched a prospective, multicenter observational study aimed at assessing the predictive value of iPET after one ABVD (iPET1) and the kinetics of response assessed by sequential PET scanning. PATIENTS AND METHODS: Consecutive patients with newly diagnosed classical Hodgkin's lymphoma underwent interim PET scan after one ABVD course (iPET1). PETs were interpreted according to the Deauville score (DS) as negative (-) (DS 1-3) and positive (+) (DS 4, 5). Patients with iPET1 DS 3-5 underwent iPET2. RESULTS: About 106 early (I-IIA) and 204 advanced (IIB-IV) patients were enrolled between January 2008 and October 2014. iPET1 was (-) in 87/106 (82%) or (+) in 19/106 (18%) of early, and (-) in 133/204 (65%) or (+) in 71/204 (35%) of advanced stage patients, respectively. Twenty-four patients were excluded from response analysis due to treatment escalation. After a median follow-up of 38.2 (3.2-90.2) months, 9/102 (9%) early and 43/184 (23%) advanced patients experienced a progression-free survival event. At 36 months, negative and positive predictive value for iPET1 were 94% and 41% (early) and 84% and 43% (advanced), respectively. The kinetics of PET response was assessed in 198 patients with both iPETs. All 116 patients with iPET1(-) remained iPET2(-) (fast responders), 41/82 with IPET1(+) became iPET2(-) (slow responders), and the remaining 41 stayed iPET2(+) (non-responders); progression-free survival at 36 months for fast, slow and non-responders was 0.88, 0.79 and 0.34, respectively. CONCLUSION: The optimal tool to predict ABVD outcome in HL remains iPET2 because it distinguishes responders, whatever their time to response, from non-responders. However, iPET1 identified fast responders with the best outcome and might guide early treatment de-escalation in both early and advanced-stage HL.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doença de Hodgkin/diagnóstico por imagem , Doença de Hodgkin/tratamento farmacológico , Tomografia por Emissão de Pósitrons/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bleomicina/administração & dosagem , Quimiorradioterapia , Dacarbazina/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Doença de Hodgkin/patologia , Doença de Hodgkin/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Valor Preditivo dos Testes , Vimblastina/administração & dosagem , Adulto JovemRESUMO
We present the case where immune thrombocytopenia (ITP) and essential thrombocythemia (ET) sequentially appeared in the space of twenty-one years of follow-up. Impaired platelet production is present in both diseases, but clinical presentation and treatment are different. On the basis of this case history a possible role of autoimmunity as a predisposing factor to myeloproliferation has been discussed.
RESUMO
Genes involved in regulation of the nuclear factor - kappa B (NF-κB) pathway are suggested to play a role in the pathogenesis of acute myeloid leukaemia (AML). The present study aimed to assess the association between the NF-κB1, TRAF3 and TLRs genes single nucleotide polymorphisms (SNPs) and disease susceptibility as well as progression in patients with AML. For this purpose 62 patients and 126 healthy individuals were genotyped for NF-κB1 (rs28362491), TRAF3 (rs11160707; rs12147254), TLR2 (rs201786064), TLR4 (rs4986790; rs4986791) and TLR9 (rs5743836; rs187084) alleles. Three SNPs were found to be associated with the risk for the AML development. The TRAF3 (rs12147254) AA homozygosity (RR = 2.770, P = 0.0392), TLR9 (rs5743836) C wild-type allele (RR = 2.542, P = 0.0096) as well as TLR9 (rs187084) T allele (RR = 13.396, P < 0.0001) and its homozygosity (RR = 11.805, P < 0.0001) were more frequent among patients with AML than healthy individuals. The associations of the rs187084 SNP were significant for both sexes. Moreover, patients who relapsed were more frequently characterized with the presence of the rs187084 TLR9 TT genotype (P = 0.045) or the rs12147254 TRAF3 A variant (P = 0.066). In conclusion, polymorphisms within the TLR9 and TRAF3 genes are associated with predisposition to AML and may affect the progression of the disease in the Polish population.
Assuntos
Predisposição Genética para Doença , Variação Genética , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Progressão da Doença , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Mutação INDEL , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/metabolismo , Masculino , Pessoa de Meia-Idade , Mortalidade , NF-kappa B/metabolismo , Polimorfismo de Nucleotídeo Único , Risco , Transdução de Sinais , Receptores Toll-Like/genética , Adulto JovemRESUMO
Patients with type 2 diabetes mellitus have a double risk of development of cardiovascular diseases than patients without diabetes. Two thirds of patients with type 2 diabetes mellitus can die from heart attack or a cerebrovascular accident if it is not possible to influence these risks by procedures such as decreasing the blood pressure, cholesterol level, glycemia and to stop smoking. The recommendations of ADA/âEASD for therapy of type 2 diabetes mellitus emphasizes that the therapy should be conducted in such a manner as to decrease the risk of cardiovascular complications and undesirable effects, primarily hypoglycemic events. A whole line of clinical studies, e. g. DCCTâEDIC, UKPDS have documented the importance of intensive insulin therapy for achievement of normoglycemia, decreasing risk of microangiopathic complications and in followup observation, also decreasing of cardiovascular risk. An ORIGIN study with insulin glargine documented the safety of therapy of longacting insulin analog and also reduction of development of new diabetes from prediabetes. Insulin therapy with respect to the positive outcomes of study with insulin analogs moved up to the second line in algorithm therapy, immediately after metformin therapy and change of life style.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
The digestive tract plays an important role in glucose homeostasis. The important fact is that cells of the digestive tract are also the place of production of numerous regulatory peptides. Their use in the treatment of diabetes has been subject to study for many years. The paper examines the synthetic analogue of the human hormone amylin, the secretion of which coincides with the secretion of insulin. The synthetic analogue pramlintide is used in treatment of DM1T as well as DM2T. Likewise, a group of intestinal alpha-glucosidase inhibitors--acarbose in this country--was introduced into clinical practice some years ago. Both drugs share their glucose-lowering effects, but first of all they influence postprandial hyperglycemia like other antidiabetic agents of this large group affecting PPG such as incretin mimetics, DPP-4, etc. Both pramlintide and acarbose have find their specific in the treatment of postprandial blood glucose.
Assuntos
Acarbose/uso terapêutico , Glicemia/efeitos dos fármacos , Inibidores de Glicosídeo Hidrolases , Homeostase/fisiologia , Hipoglicemiantes/uso terapêutico , Polipeptídeo Amiloide das Ilhotas Pancreáticas/uso terapêutico , Acarbose/efeitos adversos , Acarbose/farmacologia , Glicemia/metabolismo , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/metabolismo , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/farmacologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/efeitos adversos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/farmacologiaRESUMO
The purpose of this study was to analyze glutathione antioxidant defense system in elderly patients treated for hypertension. Studies were carried out in the blood collected from 18 hypertensive and 15 age- and sex-matched controls, all subjects age over 60. Hypertensives were on their usual antihypertensive treatment at the time of blood collection. The concentration of glutathione (GSH) in whole blood and activities of glutathione peroxidase (GPx-1), glutathione transferase (GST), and glutathione reductase (GR) in erythrocytes were measured. The data from patients and controls were compared using independent-samples t test. P value of 0.05 and less was considered statistically significant. We observed increased glutathione-related antioxidant defense in treated hypertensive elderly patients (HT) when compared with healthy controls (C). Mean GSH concentration was significantly higher in HT when compared with C: 3.1 ± 0.29 and 2.6 ± 0.25 mmol/L, respectively, P < 0.001. Mean activity of GR was significantly higher in HT group if compared with C: 83.4 ± 15.25 U/g Hb versus 64.2 ± 8.26 U/g Hb, respectively, P < 0.001. Mean activity of GST was significantly higher in HT group compared with C: 3.0 ± 0.60 mmol CDNB-GSH/mgHb/min and 2.6 ± 0.36 mmol CDNB-GSH/mgHb/min, respectively, P < 0.05. No difference in GPx activity was observed between two groups. These results show that glutathione-related antioxidant defense system was enhanced in elderly hypertensive patients treated for their conditions. This suggests important role of glutathione system in blood pressure regulation. Alterations in concentration and activity of antioxidants observed during antihypertensive medication are likely to be related to the effect of the treatment on NO bioavailability.
Assuntos
Anti-Hipertensivos/uso terapêutico , Glutationa/sangue , Hipertensão/tratamento farmacológico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Estudos de Casos e Controles , Feminino , Glutationa Peroxidase/sangue , Glutationa Redutase/sangue , Glutationa Transferase/sangue , Humanos , Hipertensão/sangue , Hipertensão/fisiopatologia , Masculino , Polônia , Regulação para Cima , Glutationa Peroxidase GPX1RESUMO
Hyperglycemia and insulin resistance develop in the majority of severe acute illness and/or injury. One of the main causes of hyperglycemia in critically ill patients is the release of counterregulatory stress hormones and proinflammatory cytokines, in addition to increased production of glucose along with its decreased utilization. Hyperglycemia plays an important role not only in influencing the cascade of inflammatory cytokines, but it also increases oxidative stress. In the past, stress hyperglycemia was thought to be an evolutionary protective, natural adaptive response of the body to current threat, which allows increased entry of glucose into the cells of non-insulin-tissues, thus improving chances for survival. At present, however, this state of insulin resistance, glucose intolerance and hyperglycemia is called "stress diabetes" or "diabetes of injury". Ever since the time of the breakthrough "Leuven" study, which brought significant reduction in morbidity and mortality in surgical critically ill patients with tight glycemic control, hospitals, particularly their intensive care units, have focused on the treatment of hyperglycemia. Although extensive observational data have shown a consistent, almost linear relationship between blood glucose concentrations seen in hospitalized patients and the incidence of adverse clinical results, there have been particular doubts concerning the universality of control, its safety, and pitfalls resulting from hypoglycemia. This controversial debate is currently enriched by the recent international trial - the NICE-SUGAR, whose post-hoc analyses are currently underway. Despite the controversy there is no doubt that the deliberate control of blood glucose control in critically ill patients is justified. It is the insulin application regimen--the insulin protocol per se--that remains the biggest problem in the implementation of glycemic control. Regarding targets, it is necessary to take into account that the best positive effects on outcomes can be anticipated in certain subgroups of critically ill patients, which is currently the subject of further study. Continued streamlining, achieving optimal blood glucose ranges in critically ill patients will allow us to develop and apply computer algorithms that greatly simplify and improve continuous monitoring of blood glucose. Procedures seeking optimal intensive control in critically ill patients are accepted in intensive care units. However, it is undoubtedly necessary to improve monitoring techniques and the quality of biosensors in order to ensure the safety and effectiveness of interventions aimed at reducing blood glucose levels while using advanced protocols. Automatic closed systems are a promise for the future.
Assuntos
Glicemia/análise , Estado Terminal/terapia , Hiperglicemia/tratamento farmacológico , Insulina/uso terapêutico , Intolerância à Glucose , Humanos , Hiperglicemia/sangue , Hiperglicemia/complicações , Hiperglicemia/fisiopatologia , Resistência à InsulinaRESUMO
Sialic acids are important constituents of animal tissue glycoconjugates and are also present in the antigens of some bacterial strains. Capsular polysaccharides with sialic acid (NeuAc) have been extensively studied with regard to sensitivity to the bactericidal action of serum, whereas little is known in this regard about lipopolysaccharides (LPS) which contain NeuAc. Strains of Salmonella O48, able to infect animals and containing the same structures of LPS with NeuAc, were examined for their susceptibility to the bactericidal action of normal bovine serum (NBS). The strains showed varied sensitivity to the bactericidal action of NBS, which indicates that the expression of LPS containing NeuAc residues is not critical for the strains' resistance to the serum's activity. In this study the mechanisms of complement activation responsible for killing serum-sensitive Salmonella O48 rods by NBS were also established. Three such mechanisms were distinguished: activation of the classical/lectin pathways, important (decisive) in the bactericidal mechanism of complement activation, parallel activation of the classical/lectin and alternative pathways, and independent activation of the classical and lectin or the alternative pathway.
Assuntos
Atividade Bactericida do Sangue/fisiologia , Bovinos/sangue , Ativação do Complemento/fisiologia , Lipopolissacarídeos/química , Ácido N-Acetilneuramínico/química , Salmonella/classificação , Animais , Lipopolissacarídeos/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Salmonella/metabolismo , Soro/imunologiaRESUMO
MS is a major atherogenic syndrome in our population. The concept of MS has had a very positive effect on our knowledge of the most serious civilization diseases, the genotypic constellation of MS, although monogenic defects explain only a very small part of pathological defects. It is certain, however, that a crucial role played is by interactions between genetic factors and risk factors of external environment. Undoubtedly, insulin resistance, central obesity and impaired metabolism of adipose tissue play an important role in the pathogenesis of MS, and there are other pathogenetic theories. The author discusses briefly the history of MS and presents the best-known definitions starting with the 90s ofthe last century, ADA and EASD reservations towards MS, as well as the new harmonized definition from 2009. This modified definition ofMS has been adopted in practice in the Czech Republic due to the Czech Institute ofmetabolic syndrome. The author discusses in greater detail the WHO expert report from 2010, which indicates some limitations of diagnostic criteria for MS. Despite all the objections the expert report provides reasons to support the use of the term metabolic syndrome, and metabolic syndrome is considered to be a recognized concept that focuses attention on the importance of comprehensive, multifactorial health problems. Finally, the author mentions sub-problems related to MS, which will have to be resolved in collaboration with diabetologists.
Assuntos
Síndrome Metabólica , Humanos , Síndrome Metabólica/complicações , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/fisiopatologiaRESUMO
Predictive genetics uses genetic testing to estimate the risk in asymptomatic persons. Since in the case of multifactorial diseases predictive genetic analysis deals with findings which allow wider interpretation, it has a higher predictive value in expressly qualified diseases (monogenous) with high penetration compared to multifactorial (polygenous) diseases with high participation of environmental factors. In most "civilisation" (multifactorial) diseases including diabetes, heredity and environmental factors do not play two separate, independent roles. Instead, their interactions play a principal role. The new classification of diabetes is based on the implementation of not only ethiopathogenetic, but also genetic research. Diabetes mellitus type 1 (DM1T) is a polygenous multifactorial disease with the genetic component carrying about one half of the risk, the non-genetic one the other half. The study of the autoimmune nature of DM1T in connection with genetic analysis is going to bring about new insights in DM1T prediction. The author presents new pieces of knowledge on molecular genetics concerning certain specific types of diabetes. Issues relating to heredity in diabetes mellitus type 2 (DM2T) are even more complex. The disease has a polygenous nature, and the phenotype of a patient with DM2T, in addition to environmental factors, involves at least three, perhaps even tens of different genetic variations. At present, results at the genom-wide level appear to be most promising. The current concept of prediabetes is a realistic foundation for our prediction and prevention of DM2T. A multifactorial, multimarker approach based on our understanding of new pathophysiological factors of DM2T, tries to outline a "map" of prediabetes physiology, and if these tests are combined with sophisticated methods of genetic forecasting of DM2T, this may represent a significant step in our methodology of diabetes prediction. So far however, predictive genetics is limited by the interpretation of genetic predisposition and individualisation of the level of risk. There is no doubt that interpretation calls for co-operation with clinicians, while results of genetic analyses should presently be not uncritically overestimated. Predictive medicine, however, unquestionably fulfills the preventive focus of modern medicine, and genetic analysis is a perspective diagnostic method.
Assuntos
Diabetes Mellitus/genética , Diabetes Mellitus/classificação , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/prevenção & controle , Predisposição Genética para Doença , Testes Genéticos , Humanos , Fatores de RiscoRESUMO
The concept of prediabetes has been discussed since the 1950's. After 1980, WHO expert guidelines on the classification of diabetes according to its stages of development became common. These guidelines also included statistically significant risk groups with diabetes likely to develop in the future. The term Impaired Glucose Tolerance (IGT) was officially introduced by WHO in 1979, with an additional category referring to changes in glucose metabolism to be included later on--the Impaired Fasting Glucose--IFG. The term prediabetes mellitus began to be used again after 2000, and after 2003 diagnostic criteria to delimit diabetes and prediabetes came into use. Progressively, evidence was gathered on the involvement of hyperglycaemia and other metabolic abnormalities in patients with type 2 diabetes in creating conditions for the development of atherosclerosis. The last decade saw re-emerging publications dealing with the abnormalities of glucose metabolism, and subsequent statements from ADA, IDF and other organisations proposing the techniques of screening, diagnosis, monitoring and/or therapy of prediabetes. Recently, the American Diabetes Association clearly specifes the diagnosis of prediabetes, whereby prediabetes is defined within the scope of the diabetic disease. Prediabetes/diabetes reflect the continuum of the risk of microvascular and macrovascular outcomes. For these reasons, methods have been developed to delay the progression of prediabetes to diabetes. An ADA panel suggests that individuals with prediabetes should be enrolled in a program of intensive lifestyle intervention, with a specific group of patients at risk to be considered for therapy with metformin. Additional methods of prevention will be introduced into practice on the basis of new studies.
Assuntos
Diabetes Mellitus/prevenção & controle , Estado Pré-Diabético/diagnóstico , HumanosRESUMO
AIM: The aim of the study was to examine the levels of adhesion molecules, high-sensitivity C-reactive protein (hs-CRP) and lipid spectrum of type 2 diabetic subjects with proven silent myocardial ischemia. METHODS: We included in the study 19 patients with ischemia (Group 1) and 16 patients without ischemia (Group 2). We documented silent ischemia by an exercise-myocardial single photon emission computed tomography. We examined the levels of total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, vascular cell adhesion molecule 1, intercellular adhesion molecule 1, E-selectin, HbA1c, microalbuminuria (MAU), hs-CRP and carotid intima-media thickness. RESULTS: The differences among the values of lipids, adhesion molecules, HbA1c, hs-CRP, MAU between the groups were not statistically significant. E-selectin levels positively correlated with triglyceride levels in the group 1 (Spearman correlation, P<0.05). This correlation was not proven in the Group 2. CONCLUSION: Statistically differences between the study groups were not significant. Levels of E-selectin positively correlated with high triglyceride levels in type 2 diabetic subjects with silent ischemia. This correlation documents a disturbance of the reverse cholesterol transport system.
Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Selectina E/sangue , Isquemia/etiologia , Extremidade Inferior/irrigação sanguínea , Isquemia Miocárdica/etiologia , Triglicerídeos/sangue , Albuminúria/etiologia , Proteína C-Reativa/metabolismo , Artérias Carótidas/patologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/sangue , Isquemia/metabolismo , Isquemia/patologia , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Molécula 1 de Adesão de Célula Vascular/sangueRESUMO
Physical activity is an integral part of treatment for type 1 diabetes mellitus (DM1T) and type 2 diabetes mellitus (DM2T). A programme of regular physical activity adapted to the complications in effect is recommended for all diabetics. Diabetes mellitus has become a problem and an entirely distinct illness for modern cardiology, especially because of the exceptional development of accelerated atherosclerosis. Long term training brings has long term positive effects on blood sugar and insulin sensitivity. There is no doubt that physical activity plays a key role in the regulation of body weight and the reduction in fat deposits for diabetics, with entirely positive results in therapy and the prevention of metabolic syndrome, manifestation of diabetes and reduction of metabolic and cardiovascular risk in diabetic patients. Although physical activity has an extraordinarily positive effect on a diabetic's organism, there are also risks that the patient should be made aware of. There is a risk during acute exertion, especially for patients undergoing medication therapy. The possible complications that may be caused by physical exertion should be avoided by suitable patient education. There are increasing levels of strong evidence that regular physical activity contributes to primary and secondary prevention of metabolic syndrome, diabetes, especially type 2 diabetes and obesity and is associated with a reduced risk of early death. It has been shown that physical activity improves body composition. In summary it can be said that only regular physical exertion that is determined individually and set precisely in terms of both quantity and quality can achieve the therapeutic objective for the taught patient. Physical activity programmes should be designed for all age groups of diabetics because the risk of chronic illness for diabetics, especially cardiovascular illness, increases with age.
Assuntos
Diabetes Mellitus/terapia , Diabetes Mellitus/metabolismo , Terapia por Exercício , HumanosRESUMO
A gas-liquid chromatographic-mass spectrometric (GLC-MS) method was applied to the detection of 3-deoxy-d-manno-2-octulosonic acid (Kdo), a constituent of bacterial lipopolysaccharide (LPS, endotoxin). Samples containing LPS were dried, methanolyzed with 2 M HCl in methanol at 60 degrees C for 1 h and acetylated with acetic anhydride and pyridine (1:1, v/v) solution at 100 degrees C for 30 min, then the products were analyzed by GLC-MS or GLC-MSMS. Four acetylated methylglycoside methyl ester derivatives of Kdo are formed in these conditions, namely one with pyranose ring (Kdo1), two derivatives in the furanose form (Kdo2 and 3) and one derivative of anhydro Kdo (Kdo4), as results from their mass fragmentation patterns. Synthetic Kdo produced mainly Kdo4 derivative, whereas Kdo1 of pyranose ring shape was the predominating derivative formed from LPS. The ion fragment of m/z 375 was selected for the specific detection of this Kdo1 derivative, which might be applied for the endotoxin determination. That approach was used for the analysis of preparations of bacteria, bacteriophages and samples of animal sera. In order to ensure the removal of phosphate substitutions from Kdo, methanolyzed samples can be treated with alkaline phosphatase (2.6 U, pH 9.2, 37 degrees C, 15 min), what was elaborated on Vibrio LPS preparation.
Assuntos
Endotoxinas/análise , Acetilação , Animais , Bacteriófago T4/metabolismo , Meios de Cultivo Condicionados/análise , Endotoxinas/química , Endotoxinas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Metanol , Metilglucosídeos/metabolismo , Ratos , Açúcares Ácidos/análise , Vibrio cholerae/químicaRESUMO
Bacteriophages (phages) as bacterial viruses are generally believed to have no intrinsic tropism for mammalian cells. In this study the interactions between phages and various eukaryotic cells were investigated. Binding of phages to the membranes of cancer and normal blood cells was observed. Moreover, it was shown that the wild-type phage T4 (wtT4) and its substrain HAP1 with enhanced affinity for melanoma cells inhibit markedly and significantly experimental lung metastasis of murine B16 melanoma cells by 47% and 80%, respectively. A possible molecular mechanism of these effects, namely a specific interaction between the Lys-Gly-Asp motif of the phage protein 24 and beta3-integrin receptors on target cells is proposed. It was also shown that anti-beta3 antibodies and synthetic peptides mimicking natural beta3 ligands inhibit the phage binding to cancer cells. This is in line with the well-described beta3 integrin-dependent mechanism of tumor metastasis. It is concluded that the blocking of beta3 integrins by phage preparations results in a significant decrease in tumor invasiveness.
Assuntos
Bacteriófago T4/fisiologia , Integrina beta3/fisiologia , Melanoma Experimental/terapia , Transdução de Sinais , Animais , Humanos , Melanoma Experimental/patologia , Melanoma Experimental/secundário , CamundongosRESUMO
Optimal compensation in patients with type 2 diabetes is individualization of therapy according to the stage of the disease and ratio of the main pathophysiological disorders. Because of the hitherto inadequate effectiveness of known procedures attention is focused on seeking new more effective procedures either based on the use of known molecules of oral antidiabetics or introduction of new substances.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Administração Oral , Diabetes Mellitus Tipo 2/metabolismo , Combinação de Medicamentos , Humanos , Hipoglicemiantes/farmacocinéticaRESUMO
Numerous studies have shown that lysosomal proteinases play an important role in carcinogenesis. The enzymatic activity of tumor-associated proteases is counter-balanced by specific inhibitors. Photodynamic therapy (PDT) is a technique which involves photoexcitation of sensitizing drugs retained in neoplastic tissue that is subsequently destroyed. Intraperitoneal injections of hematoporphyrin derivative (HpD) were given at a dose of 20 mg/kg in rats transplanted with mammary carcinoma. A halogen lamp was used 24 hours later at 630 +/- 20 nm and total dose--200 J/sq.cm. Cysteine proteinase inhibitor (CPI) was dissolved in saline and injected subcutaneously in doses of 50 mg and 200 mg per animal. The effectiveness of the treatment was evaluated with regard to survival time and tumor response and to depth of necrosis. In several cases tumors completely disappeared following HpD-PDT + CPI. The number of complete tumor responses was higher when PDT + 200 mg of CPI was used, i.e. 6 out of 10 rats. Promising results have also been obtained with regard to survival time of treated animals and to induction of tumor necrosis. We may presume that a combination of PDT and proteinase inhibitors could be a useful tool in further anticancer studies and, hopefully, in anticancer therapy.