Autoantibody systems in rheumatoid arthritis: specificity, sensitivity and diagnostic value

This review focuses on the mechanisms of stress response in the synovial tissue of rheumatoid arthritis. The major stress factors, such as heat stress, shear stress, proinflammatory cytokines and oxidative stress, are discussed and reviewed, focusing on their potential to induce a stress response in the synovial tissue. Several pathways of stress signalling molecules are found to be activated in the synovial membrane of rheumatoid arthritis; of these the most important examples are heat shock proteins, mitogen-activated protein kinases, stress-activated protein kinases and molecules involved in the oxidative stress pathways. The expression of these pathways in vitro and in vivo as well as the consequences of stress signalling in the rheumatoid synovium are discussed. Stress signalling is part of a cellular response to potentially harmful stimuli and thus is essentially involved in the process of synovitis. Stress signalling pathways are therefore new and promising targets of future anti-rheumatic therapies.     

Adenovirus Serotype 5 Variants Defective in Early Genes: Selective Replication in p53-Deficient Human Tumor Cells

Site-directed mutagenesis was used to construct human adenovirus serotype 5 (Ad5) variants defective in E1A or E1B. Mutant Adel3 with deletion from E1A was markedly attenuated in permissive cell cultures regardless of the p53 status, and replicated efficiently only in cells of the complementing 293 line. Mutant Adel2 with deletion from E1B55K infected the 293 line cells and p53-deficient human tumor cells (A431, SW480, HEp2) with efficiencies similar to those of Ad5, whereas its replication in normal p53-positive cells was substantially limited. Thus, Adel2 proved to be capable of selective infection and lysis of p53-deficient human tumor cells in vitro. On intratumor injection, Adel2 dramatically suppressed the growth of human epidermoid carcinoma (A431) in nude mice. Adel2 is thus a promising model for designing therapeutic agents against p53-deficient human tumors.     

Human exposure to mycotoxins in Egypt

This investigation examined the exposure of Egyptian infants to Aflatoxin M₁ (AfM₁) and of lactating mothers to Aflatoxin B₁, using AfM₁ in human milk as a biomarker for exposure to AfB₁. The presence of ochratoxin A (OA) in human milk was also investigated to determine the levels of infants exposure to OA from human milk. The results indicated that AfM₁ was found in 66 (55 %) of 120 human milk samples with a mean of 0.3 ± 0.53 ng/mL (range 0.02 to 2.09 ng/mL). OA was found in 43 (35.8 %) of 120 human milk samples with a mean of 21.1 ± 13.7 ng/mL (range 5.07 to 45.01 ng/mL), which will cause a daily intake of OA from human milk exceeding the suggested tolerable dose of 5 ng/kg_-1 of OA body weight. On the other side AfM₁ was found in 25 % of blood samples (5 out of 20 samples), at a mean of 1.18 ng/mL, but it was detected only in one urine sample (1 out of 20 samples). OA was detected only in 2 out of 13 blood samples (15.4 %) with an average 3.67 ng/mL. Whereas OA was not detected in all analyzed urine samples.     

I/D polymorphism in the angiotensin-converting enzyme gene in men with myocardial infarction at young age]

The rate of D allele did not differ between patients with ischemic heart disease (IHD) who had myocardial infarction before the age 45, and healthy males. The DD genotype of the ACE gene was much more frequently encountered in the patients than in healthy males. The findings suggest that the DD genotype is an independent risk factor of the IHD and myocardial infarction in young patients.     

Effect of phosphatidylglycerol on the incorporation process of cytochrome P-450 in liposomes from dimyristoylphosphatidylcholine

Using the electron paramagnetic resonance (EPR) method with spin-labeled fatty acids and gel-penetrating chromatography, the effect of phosphatidylglycerol on cytochrome P-450 incorporation into liposomes from dimyristoylphosphatidylcholine was investigated. An addition of phosphatidylglycerol caused an increase in the protein content of the proteoliposomes as well as their accelerated formation at temperatures below and above the liposome phase transition temperature (Ts). The dependence of the proteoliposome formation rate on the phosphatidylglycerol content in the liposome mixture is described by complex kinetics with a maximum in the presence of 10 mol.% of the negatively charged phospholipid. The mechanism of proteoliposome formation is discussed in terms of asymmetric distribution and phase state of the phospholipids in the original vesicles.     

Experience in the absolute calculation of pasture ixodid ticks (Parasitiformes, Ixodidae) on the eastern macroslopes of Sikhoté-Alin]

A new technique is suggested for absolute registration of adult ixodid ticks with an improved furrow plough. Due to this the number of ticks can be estimated per square unit to various biotopes. As a result of registrations conducted in 1973 the density of ticks populations from the main landscape zones of eastern Sikhote-Alin (from watershed spruce-abietic forests to coastal oak woods) was estimated for the first time.     

Isolation, identification and properties of a new thyroxine-binding protein--apolipoprotein A-1 from human blood serum]

A protein having a molecular mass of about 25 kWa was isolated by thyroxin (T4)-Sepharose affinity chromatography from human blood serum; its properties were found to be distinct from those of known T4-binding proteins. Using immunodiffusion, radioimmunoassay, lipid analysis, differential precipitation and electrophoresis, it was shown that the isolated protein is a component of high density lipoprotein (HDL) particles and represents an apolipoprotein A-1 (apoA-1). Using cholate-Sepharose chromatography apoA-1 was separated from the lipid moiety and contaminant proteins, and apoA-1 was effectively isolated directly from the blood serum. Apo-A-1-HDL and apoA-1 obtained by affinity chromatography as well as the HDL3 fraction isolated by a standard ultracentrifugation technique, all displayed a T4-binding activity, the affinities for the hormones being of the same order of magnitude. The T4 interaction with these preparations induced difference UV-absorption signals, altered the characteristics of apoA-1 intrinsic fluorescence without affecting the circular dichroism of the protein-hormone system. The binding of spin-labelled T4 to apo-1, apoA-1-HDL or HDI3 caused substantial changes in the shape of the ESR spectrum and an increase in the apparent rotational correlation time. The mobility of the radical fragment of spin-labelled T4 depended on the composition and properties of the protein preparation. The electron spectroscopy data suggest that the T4-HDL interaction occurs via specific mechanisms and that the molecular structures of the complexes formed thereby are not characteristic of other known T4-binding proteins.