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PubMed1989

CR1 polymorphism in hydralazine-induced systemic lupus erythematosus: DNA restriction fragment length polymorphism.

The contribution of genetic factors in the reduction in erythrocyte CR1 levels observed in hydralazine (Hz) induced systemic lupus erythematosus (SLE) was investigated by determining the frequency of a HindIII restriction fragment length polymorphism (RFLP) in the CR1 gene. This RFLP is associated with quantitative erythrocyte CR1 expression. Individuals who have developed SLE as a reaction to Hz therapy, consanguinous relatives of the Hz-SLE patients, controls who had been treated with Hz without any adverse reaction, and the consanguinous relatives of these controls were included in this study. No difference was found in the frequency of occurrence of the alleles associated with CR1 expression between the Hz-SLE patients and the control groups (P greater than 0.2). Individuals from the Hz-SLE group who were homozygous for the 7.4 kb 'high expressor' allele had lower mean levels of erythrocytes CR1 (564 +/- 65) than the corresponding homozygous subgroups within the Hz-SLE relative group (774 +/- 46), the Hz control group (756 +/- 80) and the Hz control relatives group (825 +/- 66). In addition, 50% of the Hz-SLE patients in the 'high expressor' subgroup who had less than 500 CR1 per erythrocyte had elevated levels of circulating immune complexes. This study suggests that individuals who are genetically low expressors of erythrocyte CR1 are not predisposed to developing SLE in response to Hz therapy, and that in a subgroup of genetically 'high expressors', low CR1 levels are associated with elevated levels of circulatory immune complexes.

Alleles↗

PubMed1980

[Physiological polymorphism of grass frog populations. IV. Effect of stress on the phenotypic expression of population polymorphism judged by the level of heat resistance of muscle tissue].

A study was made on the polymorphism of the population of Rana temporaria by the heat resistance of muscle tissue. Stress resulted in the elimination of group differences in the heat resistance of muscles. Thus, the phenotypical response of individuals to stress is masking the genotypical heterogeneity of the population judged from the heat resistance of muscle tissue.

Acclimatization↗

PubMed1993

Genetic structure of natural populations of Dryas iulia (Lepidoptera: Nymphalidae) revealed by enzyme polymorphism and mitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLP).

Dryas iulia appears to have undergone a mode of evolution different from that of other members of its subfamily (Heliconiinae). While other species constitute highly subdivided and inbred populations, those of D. iulia are thought to be large and uniform. Analyzing six samples from Southern Brazil (state of Rio Grande do Sul) in relation to three enzyme systems (EST, LAP, and PGM) and their mtDNA RFLP patterns, we found that they are very similar at the molecular level. The F statistics for enzyme polymorphism data revealed that inbreeding makes a great contribution to the population homozygosity, since FIS equals 0.1322 and FST equals 0.0023. Since the chi-square test showed that FST is not significant, we conclude that all localities belong to the same population. The mtDNA differentiation was about 12 times greater than for nuclear genes; FST was equivalent to 0.0265. We suggest that this difference is due to a higher dispersal of males, in relation to females.

Animals↗

PubMed2002

Polymorphism of the CNS active drug Org 13011: the application of high temperature analysis to detect new polymorphs.

The polymorphism of the CNS active compound Org 13011 was studied using different crystallisation methods (i.e. different solvents and cooling rates). The samples were analysed by Raman, solid state NMR, X-ray powder diffraction (XRPD) and thermal analysis. This led to the characterisation of two crystalline forms A and B. Further high temperature analysis using Raman, XRPD, solid state NMR and DSC revealed another two (high temperature) crystalline forms C and D. The transitions to the high temperature crystalline forms occur at temperatures of about 60 degrees C. This study shows that the application of high temperature experiments is useful and can lead to the discovery of new crystalline forms.

Central Nervous System Agents↗

PubMedDate not supplied

Polymorphism of indomethacin. Part I. Preparation of polymorphic forms of indomethacin.

Technologically useful methods of preparing defined polymorphic forms of indomethacin (especially gemma-form) have been described. The influence of various crystallization parameters on the formation of individual form of indomethacin have been discussed.

Chemical Phenomena↗

PubMedDate not supplied

Polymorphism of indomethacin. Part II. Identification and rapid determination of polymorphic forms of indomethacin by IR spectrometry.

A procedure is described, which make it possible to determine the content of individual polymorphic forms of indomethacin in their mixture by IR spectrometry. IR spectra recorded in the range of 1600--1800 cm-1 have been used in the determinations. The method is especially useful for analytical control of the technological process of preparing the most pharmacologically active-gemma-form of indomethacin.

Indomethacin↗

PubMed2000