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Biomedical subjects

M Karelson

Publications and source records attributed to M Karelson.

12 recordsLinked to original sources
PubMed2005

Possible relations between the polymorphisms of the cytokines IL-19, IL-20 and IL-24 and plaque-type psoriasis.

The aim of present study was to elucidate the role of the interleukin (IL)-24 gene in predicting risk for plaque-type psoriasis and to describe the linkage disequilibrium (LD) pattern emerging from the genes of IL-19, IL-20 and IL-24. Genes encoding IL-19, IL-20 and IL-24 locate in the region q32 of chromosome 1. The association between the single-nucleotide polymorphisms (SNPs) or haplotypes of the IL-24 gene and the susceptibility of psoriasis was not found. However, a significant protective effect of the combined haplotype CAAAC of IL-20 and IL-24 genes against plaque-type psoriasis was established (OR 0.154). Protective effect against psoriasis was also observed with haplotype TGGGT (OR 0.591) and haplotype CGAGT (OR 0.457). Performing a comprehensive analysis using the data regarding SNPs of IL-24 gene together with the previously published data regarding IL-19 and IL-20 SNPs, we identified two haplotype blocks within the region q32 of chromosome 1. The main result of the present study is that while the IL-19/IL-20 extended haplotype CACCGGAA is a significant susceptibility factor for psoriasis (previous study), IL-20/IL-24 haplotypes CAAAC, TGGGT and CGAGT have a significant protective effect. Nevertheless, family-based studies are required to confirm the impact of IL-19, IL-20 and IL-24 genes in the genetic predisposition for psoriasis.

Adolescent↗
PubMed2004

Combined haplotype analysis of the interleukin-19 and -20 genes: relationship to plaque-type psoriasis.

There is increasing evidence to suggest that the newly discovered cytokines interleukin (IL)-19 and -20 have a role in the function of epidermis and in psoriasis. The genes encoding these cytokines locate into the genomic IL-10 region on human chromosome 1. The aim of the present study was to analyze whether single-nucleotide polymorphisms (SNPs) in these genes have an impact on the susceptibility for psoriasis. From pairwise linkage disequilibrium (LD) matrix of the IL-19 and -20 gene polymorphisms, what reflects the nonrandom association of alleles at these markers, it was apparent that IL-19 and -20 genes form one block of LD. We found that the HT3 CACCGGAA haplotype of the IL-19 and -20 genes was associated with an increased risk of psoriasis, reflecting its role in determining susceptibility to plaque-type psoriasis. Although association analysis of the IL-19 gene indicated that minor alleles of the IL-19 gene SNPs (rs2243188, rs2243169 and rs2243158) revealed protective effect to psoriasis and haplotype analysis of the IL-19 gene proved significant protective effect of the TGATA haplotype in case of late-onset disease, combined haplotype analysis of the IL-19 and -20 genes demonstrated that protective effect of the IL-19 gene is secondary to the susceptibility effect of the IL-20 gene.

Alleles↗
PubMed2002

Terbinafine: efficacy and tolerability in young children with tinea capitis due to Microsporum canis.

AIMS: We carried out an open, prospective, uncontrolled study to evaluate the efficacy and tolerability of terbinafine in the treatment of young children with tinea capitis due to Microsporum canis. METHODS: A total of 83 healthy, immunocompetent children (age range 2-13 years) were enrolled in eight centres in Estonia, Latvia and Lithuania. Patients received oral terbinafine in dosages based on weight, 62.5 mg for those weighing 10-20 kg, 125 mg for 20-40 kg, plus application of topical 1% terbinafine cream twice daily to affected areas. Treatment lasted for 4 weeks, followed by an 8-week observation (treatment-free) period. All the subjects were assessed for efficacy and tolerability at 12 weeks. RESULTS: Eighty-one subjects were available for assessment at 12 weeks: 32 had completely recovered, with no evidence of relapse during the observation period, and 21 showed mycological cure, but presented residual physical signs of infection. Thus the effective cure rate was 65.4% in an infection known to be more difficult to cure than other causes of tinea capitis. Terbinafine was well tolerated by these children. CONCLUSIONS: This study showed effective cure of two-thirds of 81 cases of tinea capitis caused by M. canis with a 4-week course of treatment. As one-third of the cases did not respond to treatment, we suggest using combined oral and topical treatment with terbinafine in children with tinea capitis caused by M. canis.

Administration, Oral↗
PubMed2001

A QSPR model for the prediction of the gas-phase free energies of activation of rotation around the N-C(O) bond.

A novel approach to predict the gas-phase rotational activation energies of amides is presented. The quantitative structure property relationship (QSPR) treatment, using the statistical package, comprehensive descriptors for structural and statistical analysis (CODESSA), resulted in a three-parameter equation with R2 = 0.982 for the deltaG(double dagger)gas, of a set of 24 N,N-dialkylamides.

Journal Article↗
PubMed2000

Quantitative relationship between rate constants of the gas-phase homolysis of C-X bonds and molecular descriptors

A quantitative structure-property relationship (QSPR) study on the kinetic parameters of the gas-phase homolysis for 287 different C-X bonds was carried out using the CODESSA program. Successful five-, four-, and three-parameter models were developed for the prediction of the log k (891 K) values. These respective multiple linear correlations were obtained by automatic selection of appropriate molecular descriptors for reagents and products, using only the information encoded in the chemical structure.

Journal Article↗
PubMed1999

Relevance of theoretical molecular descriptors in quantitative structure-activity relationship analysis of alpha1-adrenergic receptor antagonists.

A quantitative structure-activity relationship (QSAR) study of a wide series of structurally diverse alpha1-adrenergic receptor antagonists was performed using the CODESSA (Comprehensive Descriptors for Structural and Statistical Analysis) technique. Theoretical descriptors derived on a single structure and ad hoc defined size and shape descriptors were considered in the attempt of describing information relevant to receptor interaction. The relative effectiveness of these two classes of parameters in developing QSAR models for native (alpha1A and alpha1B) and cloned (alpha1a, alpha1b, and alpha1d) adrenergic receptor binding affinity, functional activity of vascular and lower urinary tract tissues, and in vitro and in vivo selectivity was evaluated.

Adrenergic alpha-Antagonists↗
PubMed1998

Theoretical descriptors in quantitative structure-affinity and selectivity relationship study of potent N4-substituted arylpiperazine 5-HT1A receptor antagonists.

The ability of ad hoc defined size and shape descriptors and theoretical descriptors derived on a single structure to give powerful interpretative and predictive QSAR models has been compared and evaluated with respect to the quality of the pharmacological data available for a series of structurally diverse 5-HT1A receptor antagonists, displaying selectivity towards the alpha 1-adrenergic receptor.

Molecular Structure↗
PubMed1997

Prediction of Critical Micelle Concentration Using a Quantitative Structure-Property Relationship Approach

Relationships between the molecular structure and the critical micelle concentration (cmc) of anionic surfactants were investigated using a quantitative structure-property relationship approach. Measured cmc values for 119 anionic structures, representing sodium alkyl sulfates and sodium sulfonates with a wide variety of hydrophobic and hydrophilic structures, were considered. The best multiple linear regression model involved three terms (descriptors) and had a correlation coefficient of R2 = 0.940. Very good correlations (R2 = 0.988) were obtained using three descriptors for a subset of 68 structures, with structural variation only in the hydrophobic domain. From the descriptors used in these regressions, one can conclude that the cmc is primarily dependent on the size (volume or surface area) of the hydrophobic domain and to a lesser extent on the structural complexity of the surfactant molecule.

Journal Article↗
PubMedDate not supplied

QSRR correlation of free-radical polymerization chain-transfer constants for styrene.

Quantitative structure-reactivity relationships (QSRR) are deduced for kinetic chain-transfer constants for 90 agents on styrene polymerization at 60 degrees C. Three- and five-parameter correlations were obtained with R2 of 0.725 and 0.818, respectively. The descriptors involved in the correlations are consistent with the proposed mechanism of the chain-transfer reactions.

Free Radicals↗
PubMedDate not supplied

Interpretation of quantitative structure-property and -activity relationships.

The potential utility of data reduction methods (e.g. principal component analysis) for the analysis of matrices assembled from the related properties of large sets of compounds is discussed by reference to results obtained from solvent polarity scales, ongoing work on solubilities and sweetness properties, and proposed general treatments of toxicities and gas chromatographic retention indices.

Chemical Phenomena↗
PubMedDate not supplied

QSPR analysis of flash points.

A quantitative structure property relationship study of the flash point of a diverse set of 271 compounds provided a general three-parameter QSPR model (R(2) = 0.9020, R(2)(cv) = 0.8985, s = 16.1). Use of the experimental boiling point as a descriptor gives a three-descriptor equation with R(2) = 0.9529. Use of the boiling point predicted by a four-parameter reported relationship gives a three-parameter flash point equation with a R(2) value of 0.9247.

Journal Article↗