Influence of familial cancer history on lymphoid neoplasms risk validated in the large European case-control study epilymph

Lymphomas have a potentially important familial component; large studies using recent classification systems are lacking. Based on a multicentre case-control study in seven European countries, we recruited 2480 cases of lymphoid neoplasms (LN) and 2540 controls, matched by country, age and sex. Diagnoses were established according to the World Health Organisation (WHO) classification. We estimated odds ratios (OR) and 95% confidence intervals (CI) for cancer in first-degree relatives and for the kind of relative affected. The OR of LN for a family history of haematological cancer was 1.6 (OR=1.2-2.1). The OR was particularly high for chronic lymphocytic leukaemia (CLL) (OR=2.9 [1.9-4.5]). A familial case of lymphoma increased the risk of Hodgkin's lymphoma (HL) (OR=3.4 [1.5-7.8]). No increased risk was observed for diffuse large B-cell and follicular lymphomas. For CLL and HL, the risk was similar in parents, offspring and siblings. Our study suggests familial aggregation of CLL with a family history of haematological cancer and of HL with a family history of lymphoma. The transmission pattern suggests a dominant model of heredity.     

Isolation and characterization of the Mason-Pfizer monkey virus p12 protein

The Mason-Pfizer monkey virus (M-PMV) Gag protein, precursor to the structural proteins of the infectious virion, assembles into immature capsid-like particles when expressed at high levels in bacterial cells. Similar capsid-like particles can be obtained by in vitro assembly using a high concentration of isolated Gag. M-PMV Gag contains a p12 protein that has no corresponding analogues in most other retroviruses and has been suggested to contain an internal scaffold domain (ISD). We have expressed and purified p12 and the N- and C-terminal halves (Np12 and Cp12) that are predicted to be structurally independent domains. The behavior of these proteins was analyzed using chemical cross-linking, CD spectroscopy, and electron microscopy. The N-terminal half of p12 is largely alpha-helical although the C-terminal portion lacks any apparent ordered structure. Both p12 and Np12 form high-order oligomers in vitro and when expressed in E. coli produce organized structures that are visible by electron microscopy. Interestingly, Cp12, as well as the whole protein, can form dimers in the presence of SDS. The data show that both domains of p12 contribute to its ability to multimerize with much of this potential residing in its N-terminal part, most probably within the leucine zipper-like (LZL) sequence.     

New polymorphic sites within ornithine transcarbamylase gene: population genetics studies and implications for diagnosis

Ornithine transcarbamylase (OTC) deficiency, transmitted as an X-linked trait, is the most common disorder of the urea cycle. At least 3.5% out of more than 230 mutations consist of large gene deletions, involving one or more exons. Only in 78% of OTC patients the diagnosis was confirmed on DNA level. We analysed OTC intragenic polymorphisms and haplotypes, in an attempt to contribute to the clarification of unresolved cases, in three populations (Czech, Portuguese, and Mozambican) and identified six novel nucleotide changes, all of them occurring with frequency higher than 12.5% in Europeans. Five of these polymorphisms occur with a significant frequency also in Africans. The number and frequency of haplotypes defined with the newly reported markers differ in individual populations.     

Enzyme-linked immunosorbent assays using immune complexes for the diagnosis of tuberculosis

The serodiagnosis of tuberculosis has long been the subject of investigation, but we still lack a test with widespread clinical utility. The poor sensitivity and specificity of commercial assays precludes their use as the sole means of diagnosis. All of these assays use mycobacterial antigens adsorbed onto a surface. Little attention has been paid to changes in antigen conformation that may occur as a result of passive coating of these antigens to solid supports like polystyrene. Such changes may cause technical artifacts resulting in false-positive (FP) and false-negative (FN) reactions. We have developed two different enzyme-linked immunosorbent assay (ELISA) systems, in which human serum antibodies and target antigens of Mycobacterium tuberculosis are able to associate and dissociate freely in solution to form immune complexes. In one ELISA, rabbit antibodies against M. tuberculosis, passively coated in the ELISA wells, capture the immune complexes (ICs). In the other ELISA, the ICs are detected by these same rabbit antibodies but are first captured by passively coated goat anti-rabbit IgG. We have compared these two ELISA systems with an ELISA using M. tuberculosis antigens passively adsorbed to the solid polystyrene surface of the plate. We studied sera from 81 patients with tuberculosis and 47 healthy subjects. The differences between tuberculosis (TB) patients and healthy subjects were statistically significant in all three of our ELISA systems. However, the ELISA systems using soluble M. tuberculosis antigens distinguished better between TB patients and healthy subjects than the ELISA using surface-adsorbed M. tuberculosis antigens. We suggest that in the latter ELISA, passive adsorption of the target antigens induces conformational change, generating altered epitopes that are recognized by antibodies present in the serum from even healthy people. These altered conformational epitopes are recognized by antibodies that were originally evoked by antigens other than M. tuberculosis, known as heterophile antigens.     

Agouti expression in human adipose tissue: functional consequences and increased expression in type 2 diabetes

It is well recognized that the agouti/melanocortin system is an important regulator of body weight homeostasis. Given that agouti is expressed in human adipose tissue and that the ectopic expression of agouti in adipose tissue results in moderately obese mice, the link between agouti expression in human adipose tissue and obesity/type 2 diabetes was investigated. Although there was no apparent relationship between agouti mRNA levels and BMI, agouti mRNA levels were significantly elevated in subjects with type 2 diabetes. The regulation of agouti in cultured human adipocytes revealed that insulin did not regulate agouti mRNA, whereas dexamethasone treatment potently increased the levels of agouti mRNA. Experiments with cultured human preadipocytes and with cells obtained from transgenic mice that overexpress agouti demonstrated that melanocortin receptor (MCR) signaling in adipose tissue can regulate both preadipocyte proliferation and differentiation. Taken together, these results reveal that agouti can regulate adipogenesis at several levels and suggest that there are functional consequences of elevated agouti levels in human adipose tissue. The influence of MCR signaling on adipogenesis combined with the well-established role of MCR signaling in the hypothalamus suggest that adipogenesis is coordinately regulated with food intake and energy expenditure.     

Antiphospholipid antibodies in patients with lupus nephritis

The aim of this study was to compare the prevalence of anticardiolipin antibodies with other types of antiphospholipid antibodies (aPL) (antiphosphatidylserine--aPS, antiphosphatidylinositol--aPI, antiphosphatidylethanolamine--aPE) in patients with lupus nephritis and to find if the examination of a panel of various aPL is valuable for further diagnosis of patients. Additionally we determined the levels of autoantibodies against beta2-glycoprotein I (beta2GPI) and oxidized low-density lipoprotein (anti-oxLDL) and also investigated the relationship between antibodies against beta2GPI and oxLDL, which were assessed by ELISA methods. Twenty-two patients with lupus nephritis were studied. The control group consisted of 62 healthy blood donors. A statistically significant higher occurrence of all aPLs in the patients with lupus nephritis in comparison to the control group was found. The prevalence of polyspecific antibodies, which reacted with at least two various phospholipids, was 82% in the group of SLE patients. Significantly higher levels of IgG anti-beta2GPI in the sera of SLE patients (p = 0.0003) was detected. The levels of anti-oxLDL in the sera of the patients group did not differ significantly from the control one. Some positive samples for anti-beta2GPI and negative for aCL or anti-oxLDL and vice versa were found. It ca be concluded that the production of aPL including anti-beta2GPI and anti-oxLDL in the lupus nephritis patients is higher in comparison with healthy blood donors. We assume that the estimation of various types of aPL may be important in the selection of the group patients with renal diseases. The synthesis of aPL can reflect the spreading of the autoimmune response for several antigens modified on the vessel wall.     

Stereospecific reduction of the original anticancer drug oracin in rat extrahepatic tissues

The liver is the major site of drug metabolism in the body. However, many drugs undergo metabolism in extrahepatic sites and in the gut wall and lumen. In this study, the distribution and activity of reductases in rat that reduced potential cytostatic oracin to its principal metabolite 11-dihydrooracin (DHO) were investigated. The extension and stereospecificity of oracin reduction to DHO were tested in microsomal and cytosolic fractions from the liver, kidney, heart, lung and wall of small intestine, caecum and large intestine. Intestinal bacterial reduction of oracin was studied as well. The amount of DHO enantiomers was measured by HPLC with Chiralcel OD-R as chiral column. Reductive biotransformation of oracin was mostly stereospecific for (+)-DHO, but the enantiomeric ratio differed significantly among individual tissues and subcellular fractions (from 56% (+)-DHO in heart microsomes to 92% (+)-DHO in liver cytosol). Stereospecificity for (-)-DHO (60%) was observed in bacterial oracin reduction in the lumen of small intestine, caecum and large intestine. Shift of the (+)-DHO/(-)-DHO enantiomeric ratio from 90:10 (in liver subcellular fractions) to 60:40 (in-vivo) clearly demonstrated the importance of the contribution of extrahepatic metabolism to the total biotransformation of oracin to DHO.