ABSTRACT
OBJECTIVES: Interleukin-21 (IL-21) has been shown to restore immunoglobulin production together with Interleukin-4 (IL-4) in common variable immunodeficiency syndrome (CVID). Here, we elucidate the functional and structural properties of the corresponding IL-21R : IL-4R system. PATIENTS AND METHODS: An in vitro cell culture system was established to study the molecular effects of IL-21 and IL-4 on B cell differentiation, class-switch recombination (CSR) and immunoglobulin (Ig) production in 32 paediatric patients with CVID. MHC haplotypes and the IL21 and IL21R gene were analysed by genotyping. Ternary complexes of the IL-21 respectively IL-4 receptor were set-up by homology modeling and ligand-interaction was examined by molecular dynamics (MD) simulation. RESULTS: Stimulation with IL-21, IL-4 and CD40L uniformly induced IgG and IgA production in B cells from all tested patients by initiation of both CSR and AID-independent Ig production. No mutations were found in the coding regions of the IL21 or IL21R genes and no distinct HLA allele or extended haplotype could be correlated with the amount of Ig production or the gene expression pattern induced by IL-21. MD simulations of the modelled receptor complexes showed that IL-4 and IL-21 are both able to bind to IL-4R and IL-21R complexes in an interchangeable manner. CONCLUSIONS: The function of the IL-21R : IL-4R system seems not to be related to the aetiology of CVID in paediatric patients and might be suitable for a regenerative therapy.
Subject(s)
B-Lymphocytes/immunology , Common Variable Immunodeficiency/immunology , Common Variable Immunodeficiency/therapy , Interleukin-21 Receptor alpha Subunit/drug effects , Interleukin-4 Receptor alpha Subunit/drug effects , Interleukin-4/pharmacology , Interleukins/pharmacology , Adolescent , B-Lymphocytes/drug effects , Cells, Cultured , Child , Child, Preschool , Common Variable Immunodeficiency/genetics , DNA Mutational Analysis , Female , Haplotypes/genetics , Humans , Immunoglobulin A/metabolism , Immunoglobulin Class Switching/genetics , Immunoglobulin G/metabolism , Interleukin-21 Receptor alpha Subunit/genetics , Interleukin-4/genetics , Interleukin-4 Receptor alpha Subunit/genetics , Interleukins/genetics , Male , Molecular Dynamics Simulation , Polymerase Chain Reaction , Recombinant Proteins/pharmacology , Sequence Analysis, DNAABSTRACT
A CoMFA study was undertaken to elucidate the correlation of biological activity and structural parameters of 25 dopamine D4 antagonists. A special point of interest is that we have included the atypical D4 antagonist clozapine as a structural template for all other compounds. After comparing potential protonation sites at semiempirical (AM1) and ab initio (6-31G(d)) levels of theory, possible conformations of the lead compound 3-[4-(4-chlorophenyl)piperazin-1-ylmethyl]pyrazolo[1,5-a]pyridine (FAUC 113) were investigated by systematic semiempirical conformational analysis. The final conformation of FAUC 113, which was used as a template for the other compounds in the dataset, was chosen by clustering and rigid body alignment of all conformations to clozapine. The CoMFA applied on the final alignment resulted in a q2cv of 0.739. To elucidate the influence of the absolute orientation of the molecules within the grid space, the entire dataset was systematically rotated (1296 steps) within the lattice. The Gaussian-shaped distribution of the q2cv values spanned the range of 0.699-0.794 and therefore supports the significance of the analysis.
Subject(s)
Clozapine/chemistry , Dopamine Antagonists/chemistry , Dopamine D2 Receptor Antagonists , Pyrazoles/chemistry , Pyridines/chemistry , Pyrroles/chemistry , Models, Molecular , Receptors, Dopamine D4ABSTRACT
Time-resolved fluorescence measurements were performed for a set of n-anthroyloxy fatty acids (n-AS; n = 2, 3, 6, 9, 12, 16) in both solvent and vesicle systems. The Stokes' shifts and the mean relaxation times calculated from the time-resolved emission spectra (TRES) are shown to be strongly dependent on the position of the fluorophore in small unilamellar vesicles (SUV) composed of phosphatidylcholine (PC), while they are essentially independent of the fluorophore position in isotropic paraffin oil. The concept of an intramolecular relaxation process which had been suggested to explain the wavelength dependence of the emission behaviour of the n-AS dyes in viscous solvents is supported by semiempirical calculations showing that a more planar conformation is favoured in the excited compared to the ground state. However, in order to explain the results in vesicle systems, the concept of intramolecular relaxation is not sufficient. Rather, we show that intermolecular solvent relaxation processes play the dominant role for the wavelength dependent emission behaviour in polar, viscous environments.
Subject(s)
Fatty Acids/chemistry , Fluorescent Dyes/chemistry , Membrane Lipids , Molecular Conformation , Oils , Paraffin , Pentanes , Phosphatidylcholines , Solvents , Spectrometry, FluorescenceABSTRACT
This descriptive study used the questionnaire method to investigate health lifestyle patterns of two Southern Black religious denominations. Baptists and Seventh-day Adventists (SDAs). The entire sample numbered 105 persons from urban centers. Responses of Baptists (N = 46) were compared with responses of Seventh-day Adventists (N = 59) on the seven health promoting practices identified in the studies of Belloc and Breslow (1972): hours of sleep, appropriate body weight, regularity of exercise, moderate alcohol consumption, smoking abstinence, regularity of breakfast and moderation of between meal snacks. This was the first research focusing on these health behaviors in a Black population in the South. Findings showed the groups to be significantly different only in smoking behavior, SDAs were more often nonsmokers. The salient implications for practice in this study are in the health education area for the individual, the family, the community and ethnic groups. This investigator submits that the church as a wider support system needs to be utilized by practitioners as a vehicle for client education. Several suggestions for further research are presented.
Subject(s)
Black or African American , Life Style , Morbidity , Adult , Aged , Aged, 80 and over , Female , Health Behavior , Health Education , Health Surveys , Humans , Male , Middle AgedABSTRACT
Two newly synthesized cryptands act as sensitive Na(+)- and K(+)-selective indicators for cation concentrations above 20 µM. The fluorescence properties change markedly upon cation binding. In addition, the free ligands exhibit a pronounced sensitivity to pH, which is considerably lower for the cation complexes. Time resolved fluorescence is characterized by a decay time of about 5 ns that is attributed to the diprotonated protolytic state of the uncomplexed ligands. Semiempirical calculations show the systematic influence of the nitrogen lone pairs or the N-H bond on the stability of the system. The cause of the strong fluorescence intensity increase observed upon protonation of the fluorescent cryptands may be attributed to an increase in the S1-T x energy gap as a consequence of bridgehead nitrogen protonation.
