Background: CD8+ T suppressor cells may play a role in immunoregulation. Recent studies have characterized this population by the lack of the CD28 molecule. These CD8+CD28 T cells differ phenotypically and functionally from CD8 + CD28 + T cells.
View Article and Find Full Text PDFA survey of 3820 school children in England aged 13-16 years examined sexual activity using the Transtheoretical Model (TTM) Stages of Change. A quarter (26%) of teens were sexually experienced, 44.8 per cent did not use contraception and 48.
View Article and Find Full Text PDFObjective: To directly compare distinct assays proposed to monitor human sperm quality and possibly preselect sperm populations for assisted reproductive technology (ART).
Design: Analysis of human sperm sample quality using several methodologies.
Setting: Academic and clinical institutions.
A transgenic mouse model, deficient in kinin B(1) receptor (B(1)(-/-)) was used to evaluate the role of B(2) receptor in the smooth muscle stomach fundus. The results showed that the potency of bradykinin (BK) to induce contraction in the gastric tissue was maintained whereas the efficacy was markedly reduced. The angiotensin converting enzyme (ACE) inhibitor captopril potentiated BK-induced effect in wild type (WT) but not in B(1)(-/-) fundus.
View Article and Find Full Text PDFAn insertion of residues in the third extracellular loop and a disulfide bond linking this loop to the N-terminal domain were identified in a structural model of a G-protein coupled receptor specific to angiotensin II (AT1 receptor), built in homology to the seven-transmembrane-helix bundle of rhodopsin. Both the insertion and the disulfide bond were located close to an extracellular locus, flanked by the second extracellular loop (EC-2), the third extracellular loop (EC-3) and the N-terminal domain of the receptor; they contained residues identified by mutagenesis studies to bind the angiotensin II N-terminal segment (residues D1 and R2). It was postulated that the insertion and the disulfide bond, also found in other receptors such as those for bradykinin, endothelin, purine and other ligands, might play a role in regulating the function of the AT1 receptor.
View Article and Find Full Text PDFKinins are potent vasoactive peptides generated in blood and tissues by the kallikrein serine proteases. Two distinct kinin receptors have been described, one constitutive (subtype B2) and one inducible (subtype B1), and many physiological functions have been attributed to these receptors, including glucose homeostasis and control of vascular permeability. In this study we show that mice lacking the kinin B1 receptor (B1-/- mice) have lower fasting plasma glucose concentrations but exhibit higher glycemia after feeding when compared to wild-type mice.
View Article and Find Full Text PDFThe objective of this study was to determine the concentrations of Fe, K, Na, Ca, P, Zn and Mg in colostrum and mature milk (2 months) from nursing mothers, and the correlation between the concentration of these micronutrients and newborn weight, maternal age, gestational age GA, inter-pregnancy interval, and gestational weight gain. Thirty one women donated milk on the 2nd postpartum day and on the 2nd month of lactation. Micronutrients were analysed by atomic emission spectrophotometry.
View Article and Find Full Text PDFSeveral studies have proposed that angiotensin II (Ang II) binds to its receptor AT1 through interactions with residues in helices V and VI, suggesting that the distance between these helices is crucial for ligand binding. Based on a 3D model of AT1 in which the C-terminus of Ang II is docked, we identified the hydrophobic residues of TM V and VI pointing towards the external face of the helices, which may play a role in the structure of the binding pocket and in the structural integrity of the receptor. We performed a systematic mutagenesis study of these residues and examined the binding, localization, maturation, and dimerization of the mutated receptors.
View Article and Find Full Text PDFThe interest in methods that are able to efficiently compress microarray images is relatively new. This is not surprising, since the appearance and fast growth of the technology responsible for producing these images is also quite recent. In this paper, we present a set of compression results obtained with 49 publicly available images, using three image coding standards: lossless JPEG2000, JBIG, and JPEG-LS.
View Article and Find Full Text PDFBackground And Objectives: B-cell chronic lymphoproliferative disorders (B-CLPD) are usually monoclonal expansions of a single B-cell clone. However in some cases, two unrelated B-cell clones co-exist. Additionally, cases with two B-cell subpopulations displaying a similar phenotype but distinct DNA contents exist, the exact nature of these cases remaining unknown.
View Article and Find Full Text PDFIn face of accumulated reports demonstrating that uptake of some cell-penetrating peptides occurs through previously described endocytic pathways, or is a consequence of cell fixation artifacts, we conducted a systematic analysis on the mechanism responsible for the cellular uptake of the S4(13)-PV karyophilic cell-penetrating peptide. The results reviewed here show that the S4(13)-PV peptide is able to very efficiently accumulate inside live cells in a rapid, non-toxic and dose-dependent manner, through a mechanism distinct from endocytosis. Comparative analysis of peptide uptake by mutant cells lacking heparan sulfate proteoglycans demonstrates that, although not mandatory, their presence at cell surface facilitates the cellular uptake of the S4(13)-PV peptide.
View Article and Find Full Text PDFThis study replicates innovative profiles of prevention among students not using substances but who may be at different risks for acquisition. Using the Transtheoretical Model constructs of Decisional Balance and Temptations, cluster analyses were performed on four independent samples of students (n=1240) in the USA, England and Israel. For each sample, the same four distinct profiles emerged.
View Article and Find Full Text PDFAlthough rat aorta smooth muscle cells in culture constitutively express bradykinin B1 receptors, the normotensive rat aorta does not respond to the bradykinin B1 receptor agonist des-Arg9-bradykinin, whereas vessels from the spontaneously hypertensive rat (SHR) respond to bradykinin B1 receptor agonists with cell membrane hyperpolarization and relaxation. Bacterial lipopolysaccharide also is inactive on the normotensive rat but hyperpolarizes the SHR aorta. To determine whether this could be due to the increased intracellular Ca2+ concentration ([Ca2+]i) in the SHR, we raised [Ca2+]i in normotensive rats by treatment with thapsigargin.
View Article and Find Full Text PDFActa Cir Bras
December 2007
Purpose: CD5 is a T cell marker, aberrantly express in B cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma (MCL). Other chronic B cell malignancies including hairy cell leukemia (HCL) and B cell prolymphocytic leukemia (B-PLL) are CD5 negative or express this antigen in a weak way. In this study, CD5 expression was investigated in leukemic cells from 42 patients with chronic B cell lymphoproliferative disease.
View Article and Find Full Text PDFCortical spreading depression is a neural phenomenon present in several animal species. Spreading depression features, like velocity of propagation, depends on several chemical and metabolic factors, as for example, anti-oxidants. Here we studied spreading depression-velocity changes in weaned rat-pups born from dams treated on a daily basis, either during gestation or lactation, with a carotenoid ethanolic extract (30 microg/kg/day) prepared from shrimp waste (heads).
View Article and Find Full Text PDFThe story of Brazil's evolution in sexual and reproductive health and rights during the 1990s documents not only a decade of change in the population field, but the powerful role of social movements in a democracy. Between October and December 2002, 23 people were interviewed about where they believe progress has been made in Brazil and where there are still needs in relation to population trends, sexual and reproductive rights, and health policies. This paper contains excerpts from the full report and covers the economic and political background of Brazil; the role of non-governmental and women's organisations in influencing the national agenda; the intersection of national and international agendas on population and development, HIV/AIDS, human rights, racism and other issues; changes in sexual and reproductive health policies; HIV/AIDS policy progress, perhaps most importantly mandatory free treatment for people with HIV/AIDS; recent progress in women's health, especially in relation to antenatal and obstetric services, and services addressing violence against women.
View Article and Find Full Text PDFKinins are important mediators in cardiovascular homeostasis, inflammation, and nociception. Two kinin receptors have been described, B 1 and B 2 . The B 1 receptor is normally absent in healthy tissues, but is highly induced under pathological conditions.
View Article and Find Full Text PDFTo assess the importance of the leucine residues in positions 262 and 265 of the angiotensin AT(1) receptor for signaling pathways and receptor expression and regulation, we compared the properties of CHO cells transfected with the wild type or the L262D or L265D receptor point mutants. It was found that the two mutants significantly increased the basal intracellular cyclic AMP (cAMP) formation in an agonist-independent mode. The morphology transformation of CHO cells was correlated with the increased cAMP formation, since forskolin, a direct activator of adenylate cyclase mimicked this effect on WT-expressing CHO cells.
View Article and Find Full Text PDFCancer Genet Cytogenet
July 2005
Cytosolic sulfotransferases are enzymes that catalyze the conjugation of sulfate groups to a variety of xenobiotic and endogenous substrates. A mutation in the SULT1A1 gene has been associated with decreased sulfotransferase activity. We studied 125 cancer patients and 100 healthy controls from Brazil matched by age and gender.
View Article and Find Full Text PDFAcute renal artery occlusion is rarely found in daily clinical practice. Its rarity and inespecific clinical presentation are responsible for late diagnosis or diagnostic errors, with symptoms frequently being erroneously attributed to other more common entities. There is no consensus in what concerns therapeutic options.
View Article and Find Full Text PDFThe exogenous cytokine milieu can influence Th1/Th2 polarization. Besides the differential functional properties, T lymphocytes also acquire distinct profiles of chemokine receptors. Human Th1 lymphocytes preferentially express CCR5 and CXCR3 while Th2 lymphocytes express CCR3, CCR4 and CCR8.
View Article and Find Full Text PDFChemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response, namely in allergic contact dermatitis (ACD). In this work, we investigated by flow cytometry the effect of the contact sensitizers 2,4-dinitrofluorobenzene (DNFB), 1,4-phenylenediamine (PPD) and nickel sulfate (NiSO(4)), on the surface expression of the chemokine receptors CCR6 and CXCR4 in DC. As an experimental model of a DC we used a fetal skin-derived dendritic cell line (FSDC), which has morphological, phenotypical and functional characteristics of skin DC.
View Article and Find Full Text PDFCell-penetrating peptides have been shown to translocate across eukaryotic cell membranes through a temperature-insensitive and energy-independent mechanism that does not involve membrane receptors or transporters. Although cell-penetrating peptides have been successfully used to mediate the intracellular delivery of a wide variety of molecules of pharmacological interest both in vitro and in vivo, the mechanisms by which cellular uptake occurs remain unclear. In the face of recent reports demonstrating that uptake of cell-penetrating peptides occurs through previously described endocytic pathways, or is a consequence of fixation artifacts, we conducted a critical re-evaluation of the mechanism responsible for the cellular uptake of the S4(13)-PV karyophilic cell-penetrating peptide.
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