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Rev. Soc. Bras. Med. Trop ; 52: e20180353, 2019. tab, graf
Article in English | LILACS | ID: biblio-1057248


Abstract INTRODUCTION: Dengue is an important mosquito-borne disease in tropical and subtropical regions. Adhesion molecules have not been systematically characterized in the renal tissue of patients with severe dengue (SD). The objective of this study was to detect viral antigens in samples from patients that evolved with SD, correlating with the expression of ICAM-1, VCAM-1, VE-cadherin, and E-selectin to contribute to a better understanding of the pathophysiology of SD. METHODS: Kidney specimens from patients with SD were selected according to clinical and laboratorial data and submitted to histological and immunohistochemistry analysis. A semiquantitative evaluation was performed considering positive immunostaining in 20 glomeruli. RESULTS: Viral antigens were mainly detected in distal tubules. The intense immunostaining of VCAM-1 and ICAM-1 was observed. The expression of E-selectin was discrete, and VE-cadherin expression varied from mild to moderate. VCAM-1 was slightly intense in the glomerular capsule; the expression of ICAM-1 was diffuse. E-selectin was diffuse, and VE-cadherin varied from mild to moderate. The most frequent histological findings were glomerular congestion, mild glomerulitis, acute renal injury, and glomerular atrophy. CONCLUSIONS: The results appear to demonstrate an imbalance between vascular endothelial permeability regulating events in renal lesions in SD. The increase in the expression of ICAM-1 and VCAM-1 is an in-situ indicator of higher permeability with a consequent influx of cells favoring the inflammation of the endothelium. These molecules are important in the pathophysiology of the disease and provide the possibility of developing new markers for the evaluation, clinical follow-up, and therapeutic response of patients with SD.

Humans , Male , Female , Child, Preschool , Child , Adolescent , Adult , Young Adult , Intercellular Adhesion Molecule-1/physiology , Vascular Cell Adhesion Molecule-1/physiology , E-Selectin/physiology , Severe Dengue/physiopathology , Severe Dengue/blood , Endothelium/physiopathology , Immunohistochemistry , Biomarkers/blood , Antigens, CD/physiology , Antigens, CD/blood , Cadherins/physiology , Cadherins/blood , Up-Regulation , Intercellular Adhesion Molecule-1/blood , Disease Progression , Vascular Cell Adhesion Molecule-1/blood , E-Selectin/blood , Middle Aged , Antigens, Viral/blood
Braz. j. med. biol. res ; 44(4): 276-282, Apr. 2011. ilus, tab
Article in English | LILACS | ID: lil-581490


The signaling lymphocytic activation molecule (SLAM), present on the surface of hematopoietic cells, can regulate some events of the immune responses. This modulatory action is associated with the capacity of SLAM to interact with an intracytoplasmic adapter, such as SLAM-associated protein (SAP). SLAM is constitutively expressed in most of these cells, is rapidly induced after antigenic or inflammatory stimuli, and participates in the immunological synapse. Defects in the function of the SLAM-SAP pathway contribute to immunological abnormalities, resulting in autoimmune diseases, tumors of the lymphoid tissues and inadequate responses to infectious agents. Initially, the role of SLAM was investigated using an anti-SLAM monoclonal antibody (α-SLAM mAb) identified as an agonist of the SLAM-SAP pathway, which could induce the production of interferon-γ and could redirect the immune response to a T helper 1 (Th1) cell profile. However, in this review we postulate that the SLAM-SAP pathway primarily induces a Th2 response and secondarily suppresses the Th1 response.

Humans , Antigens, CD/physiology , /metabolism , Intracellular Signaling Peptides and Proteins/physiology , Lymphocyte Activation , Receptors, Cell Surface/physiology , Signal Transduction/physiology , Antibodies, Monoclonal , Th1 Cells/immunology , Th1 Cells/metabolism , /immunology , /metabolism
Medicina (B.Aires) ; 69(2): 267-276, mar.-abr. 2009. ilus
Article in Spanish | LILACS | ID: lil-633634


En la última década se ha aportado clara evidencia de que tanto nucleósidos como nucleótidos de adenina y uridina pueden funcionar como factores de señalización extracelular. Su acción es mediada por dos tipos principales de receptores de superficie denominados purinérgicos. Los receptores P1 se activan por adenosina, y son todos metabotrópicos, mientras que los receptores de nucleótidos (ATP, ADP, UTP y UDP) y nucleótidos-azúcares (UDP-glucosa y UDP-galactosa) pueden ser metabotrópicos (P2Y) o ionotrópicos (P2X). La importancia y complejidad de este sistema de señalización se evidencia por la diversidad de mecanismos de liberación de nucleótidos al medio extracelular y por la distribución ubicua de varios grupos de ectonucleotidasas capaces de catalizar la degradación y conversión de nucleótidos. Hasta el momento se han descrito y clonado una veintena de estos receptores que modulan una variedad de respuestas, como el impulso nervioso, la respuesta inflamatoria, la secreción de insulina, la regulación del tono vascular y la percepción del dolor. En la presente revisión se describen las características estructurales y farmacológicas de los receptores purinérgicos y se analiza la interacción dinámica entre estos receptores, los nucleósidos y nucleótidos, y las ectonucleotidasas, con especial atención a la dinámica de la agregación plaquetaria, la respuesta inmune y la hidratación de las mucosas respiratorias.

In the last decade evidence accumulated that nucleosides and nucleotides of both uridine and adenine can act as extracellular signaling factors. Their action is mediated by two main types of surface receptors commonly known as purinergic. P1 receptors are metabotropic and activated by adenosine, whereas receptors for nucleotides (ATP, ADP, UTP and UDP) and nucleotide-sugars (UDP-glucose and UDP-galactose) can be either metabotropic (P2Y) or ionotropic (P2X). The importance and complexity of this signaling system is evidenced by various mechanisms of nucleotide release, as well as by the ibiquitous distribution of various types of ectonucleotidases which catalyze and convert extracellular nucleotides. Up to now about twenty receptors have been cloned and found to modulate the nerve impulse, inflammatory response, insuline secretion, the regulation of the vascular tone and nociception, among other processes. In the present review we describe the main structural and pharmacological features of purinergic receptors, and analyze how the dynamic interaction between these receptors, nucleotides and nucleosides, and ectonucleotidases modulate several biological responses. Particular focus is given to platelet aggregation and thrombus formation, the immune response and the hydration of the mucosal linings of the respiratory tract.

Animals , Humans , Antigens, CD/physiology , Apyrase/physiology , Cystic Fibrosis Transmembrane Conductance Regulator/physiology , Nucleotides/physiology , Platelet Aggregation/physiology , Receptors, Purinergic/physiology , Lung Diseases/drug therapy , Nucleotidases/physiology , Nucleotides/pharmacology , Platelet Aggregation/drug effects , Receptors, Purinergic/therapeutic use , Signal Transduction/physiology
West Indian med. j ; 56(1): 17-21, Jan. 2007.
Article in English | LILACS | ID: lil-471843


The data compiled in the present review on dibenzyl trisulphide (DTS) isolated from Petiveria alliacea L (the guinea hen weed or anamu) revealed that the compound and its derivatives could be of tremendous pharmaceutical interest. The mode of action elucidated for DTS revealed that it is a mitogen activated protein extracellular regulated kinases 1 and 2 (MAPKinases erk1 and erk 2) signal transduction molecule. Dibenzyl trisulphide caused hyper-phosphorylation of growth factor induced MAPKinases (erk 1 and erk 2) phosphorylation, a process critical for the improvement of long term memory, and is implicated in neuronal growth. Dibenzyl trisulphide and its derivatives exhibited potent anti-proliferation/cytotoxic activity on a wide range of cancer cell lines. The cytotoxic activity of DTS was increased by 70-1000 fold when bound to albumin in vitro. Dibenzyl trisulphide seems to have a cytokine switching mechanism in which it down regulates cytokines from the Type I helper cells (Th -1 cell) pathway which contained several pro-inflammatory cytokines and up-regulates those on the Type 2 helper cells (Th-2) pathway. The trisulphide up-regulates some reticuloendothelial system parameters eg granulocyte counts and increased thymic and Peyer's patches masses via cell proliferation processes which are known to be regulated via the MAPKinase signal transduction pathway. When the zygotes ofAsternia pectinifera (Starfish) were exposed to DTS at concentration of 10 mM, a dose lethal to all cancer cells tested, it was observed that the sensitive process of protein biosynthesis was not affected Similarly, the proliferation of the HOFA human fibroblast, a noncancerous cell line, was not severely affected by DTS at 8.9 microM over seven days, a concentration also lethal to most cancer cell lines tested The implications of the findings will be highlighted in the present review.

Humans , Benzyl Compounds/therapeutic use , Phytotherapy , Plant Extracts , Sulfides/therapeutic use , Antigens, CD/physiology , Cadherins/physiology , Benzyl Compounds/pharmacology , Up-Regulation/physiology , Sulfides/pharmacology , Signal Transduction/drug effects
In. Palomo González, Iván; Ferreira Vigoroux, Arturo; Sepúlveda Carvajal, Cecilia; Rosemblatt Silber, Mario; Vergara Castillo, Ulises. Fundamentos de inmunología. Talca, Universidad de Talca, 1998. p.667-98, ilus.
Monography in Spanish | LILACS | ID: lil-284832
Rev. mex. reumatol ; 11(2): 42-51, mar.-abr. 1996. tab, ilus
Article in Spanish | LILACS | ID: lil-208135


Los antígenos de diferenciación leucocitaria son moléculas que se detectan en la membrana de las células derivadas de la médula ósea y que se expresan con un patrón característico en cada una de las subpoblaciones de leucocitos, en sus variados estadios de diferenciación celular. En la práctica diaria, los antígenos de diferenciación leucocitaria son detectados con el empleo de anticuerpos monoclonales de origen murino; con el uso de diversas técnicas de laboratorio y estos anticuerpos, es factible el detectar, cuantificar, aislar y eliminar subpoblaciones definidas de células, tanto in vivo como in vitro. El conocimiento actual de los antígenos de diferenciación leucocitaria ha tenido un gran impacto en el campo de la reumatología, ya que ha facilitado grandemente el estudio de la fisiopatología de diversas enfermedades reumáticas, principalmente las de origen autoinmune. Además, los anticuerpos dirigidos en contra de los antígenos de diferenciación leucocitaria pueden ser de gran utilidad en el seguimiento y terapia de diversas condiciones caracterizadas por la presencia de inflamación y daño a tejidos

Antibodies, Monoclonal , Antigens, CD/physiology , Rheumatic Diseases/physiopathology , Membrane Glycoproteins/analysis , Immune System/cytology , Leukocytes/physiology , Cytological Techniques/standards