Apolipoprotein-defined lipoprotein abnormalities in rheumatoid arthritis patients and their potential impact on cardiovascular disease.

OBJECTIVES: The aim of this study was to explore apolipoprotein-defined lipoproteins for abnormalities when comparing non-rheumatological controls to rheumatoid arthritis (RA) patients. METHODS: Apolipoprotein and lipoprotein profiles were measured on 94 RA patients and 79 controls by immunoturbidimetric procedures, electroimmunoassays, and immunoprecipitation. Differences between means were tested with a two-sided Student t test with Satterthwaite adjustment. p-values were adjusted for multiple comparisons using the Bonferroni procedure. RESULTS: RA patients had significantly higher levels of total cholesterol (TC), triglycerides (TG), and very low density lipoprotein cholesterol (VLDL-C) than controls, but no significant differences in the levels of high density lipoprotein cholesterol (HDL-C) and LDL-C. RA patients had significantly lower levels of apolipoprotein (apo)A-I and lipoprotein (Lp)A-I:A-II, but no difference in levels of LpA-I than normal controls. There was a significant difference in the levels of LpB:C but not in LpB:C:E between RA patients and controls. The main abnormality among apoB lipoproteins was the significantly increased concentration of the LpA-II:B:C:D:E subclass in RA patients in comparison with controls. The high levels of LpA-II:B:C:D:E are also reflected in significantly increased levels of apoC-III, and apoC-III bound to apoB lipoproteins. CONCLUSION: The LpA-II:B:C:D:E subclass has potential as a new marker for cardiovascular disease (CVD) in RA patients.

Location of the nick at oriT of the F plasmid.

The oriT locus of the Escherichia coli K12 F plasmid contains a site at which one of the DNA strands is cleaved as a prelude to conjugal transmission to recipient bacteria. We have remapped this site biochemically by using oriT-containing plasmids that were purified from bacteria expressing the F transfer (tra) functions. The strand interruption was found on the transferred strand 137 base-pairs clockwise of the center of the BglII site at 66.7 on the F map. This location is consistent with the locations anticipated from studies of delta traF' plasmids, but it differs from previous results by other investigators. The strand interruption produced a 3'-OH, but the nature of the 5' terminus of the strand on the other side of the nick was not determined. Some DNA sequence motifs in the vicinity of the oriT nick site of F resemble the chromosomal site involved in formation of delta traF'purE plasmids.

A rapid and inexpensive procedure for separation of high molecular weight DNA.

A pulse field gel electrophoresis procedure suitable for a variety of uses is described. The protocol has a run time of four hours. It was developed using field inversion technology and conventional gel boxes and is run at room temperature. This procedure provides a quick and inexpensive alternative for separation of high molecular weight DNA.

Apolipoprotein B-containing lipoprotein subclasses as risk factors for cardiovascular disease in patients with rheumatoid arthritis.

OBJECTIVE: The purpose of this study was to explore whether nontraditional risk factors, such as apolipoprotein C-III (Apo C-III) and its corresponding Apo B lipoprotein (Lp) subclasses, contribute to the risk of cardiovascular disease in rheumatoid arthritis (RA) patients. METHODS: Apolipoprotein and lipoproteins were measured in 152 RA patients by immunoturbidimetric procedures, electroimmunoassay, and immunoprecipitation. Patients had a coronary artery calcium (CAC) score assessed at baseline and at year 3. Differences in the CAC scores between baseline and year 3 were calculated and dichotomized at 0, where patients with a difference score >0 were denoted as progressors and the rest were denoted as nonprogressors. Differences between means were tested with a 2-sided independent Student's t-test with Satterthwaite's adjustment. Proportion differences were tested with a chi-square test. Multiple logistic regression was performed to assess the relationship between apolipoprotein and lipoprotein levels and the dichotomized CAC score. RESULTS: Progressors accounted for almost 60% of the cohort. Progressors had significantly higher levels of triglycerides, very low-density lipoprotein (VLDL) cholesterol, total cholesterol/high-density lipoprotein (HDL), triglycerides/HDL, Apo B, LpA-II:B:C:D:E, LpB:C, Apo B/Apo A-I, Apo C-III, and Apo C-III-heparin precipitate than the nonprogressors. After adjusting for age, sex, statin use (yes/no), and hypertension (yes/no), significant risk factors of progressors were total cholesterol, triglycerides, VLDL cholesterol, LDL cholesterol, Apo B, LpB:C, Apo C-III, and Apo B/Apo A-I. CONCLUSION: Apo C-III-containing Apo B lipoprotein subclasses were found to be significantly elevated in progressors compared to nonprogressors. Many of these same lipoproteins were found to be associated with an increase in CAC scores among progressors. These lipoproteins may be considered new risk factors for progression of atherosclerosis in RA patients.

Template-driven gene selection procedure.

The hierarchical clustering and statistical techniques usually used to analyse microarray data do not inherently represent the underlying biology. Herein, a hybrid approach involving characteristics of both supervised and unsupervised learning is presented. This approach is based on template matching in which the interaction of the variables of inherent malignancy and the ability to express the malignant phenotype are modelled. Immortalised normal urothelial cells and bladder cancer cells of different malignancy were grown in conventional two-dimensional tissue culture and in three dimensions on extracellular matrices (ECMs) that were either permissive or restrictive for expression of the malignant phenotype. The transcriptome represents the effects of two variables--inherent malignancy and the modulatory effect of ECM. By assigning values to each of the biological variables of inherent malignancy and the ability to express the malignant phenotype, a template was constructed, which encapsulated the interaction between them. Gene expression correlating both positively and negatively with the template was observed, but when iterative correlations were carried out, the different models for the template converged on the same actual template. A subset of 21 genes was identified, which correlated with two a priori models or an optimised model above the 95% confidence limits identified in a bootstrap resampling with 5000 permutations of the data set. The correlation coefficients of expression of several genes were > 0.8. Analysis of upstream transcriptional regulatory elements (TREs) confirmed that these genes were not a randomly selected set of genes. Several TREs were identified as significantly over-expressed in the sample of 20 genes for which TREs were identified, and the high correlations of several genes were consistent with transcriptional co-regulation. The authors suggest that the template method can be used to identify a unique set of genes for further investigation.

Transposition of Tn1000: activity of single or directly repeated termini.

Tn1000 (gamma delta) termini IRR and IRL, or direct repetitions of IRR-IRL carried by pBR322 derivatives mediate cointegration with pOX38 at similar rates. Structures of product plasmids indicate that the transposed segments correspond to DNA bounded by IR segments in the donor plasmid. Such structures could arise by symmetric transposition from a replication intermediate.