Association of BDNF with anorexia, bulimia and age of onset of weight loss in six European populations

Several genes with an essential role in the regulation of eating behavior and body weight are considered candidates involved in the etiology of eating disorders (ED), but no relevant susceptibility genes with a major effect on anorexia nervosa (AN) or bulimia nervosa (BN) have been identified. Brain-derived neurotrophic factor (BDNF) has been implicated in the regulation of food intake and body weight in rodents. We previously reported a strong association of the Met66 allele of the Val66Met BDNF variant with restricting AN (ANR) and low minimum body mass index in Spanish patients. Another single nucleotide polymorphism located in the promoter region of the BDNF gene (-270C>T) showed lack of association with any ED phenotype. In order to replicate these findings in a larger sample, we performed a case-control study in 1142 Caucasian patients with ED consecutively recruited in six different centers from five European countries (France, Germany, Italy, Spain and UK) participating in the 'Factors in Healthy Eating' project. We have found that the Met66 variant is strongly associated to all ED subtypes (AN, ANR, binge-eating/purging AN and BN), and that the -270C BDNF variant has an effect on BN and late age at onset of weight loss. These are the first two variants associated with the pathophysiology of ED in different populations and support a role for BDNF in the susceptibility to aberrant eating behaviors.     

Molecular and serological evaluation of surface antigen negative hepatitis B virus infection in blood donors from Venezuela

Surface antigen negative hepatitis B virus (HBV) infection was evaluated in Venezuela, by molecular characterization of blood samples positive for antibodies to core antigen (anti-HBc) and negative for surface antigen (HBsAg) in blood donors (residual infections). HBV DNA was found in 11/258 samples (4.3%), and was significantly associated with high levels of anti-HBc antibodies (>25 UI/ml, P < 0.05), while no correlation was found between the presence of HBV DNA and the levels of anti-HBs. Synonymous and non-synonymous mutations were found in the HBV surface region (but not vaccine escape mutants) and in the precore/core region (precore mutants in 2/7 samples and 33-45 bp deletions near the N-terminal core region in 4/19 samples). While HBV genotype F prevails among HBsAg positive samples from blood donors in Venezuela, residual infection isolates were mainly genotypes A and D. Phylogenetic analysis of viral surface and core region revealed discrepancies in genotype designation in 6/9 samples, suggesting the presence of mixed infection or recombination. In conclusion, HBV residual infection in Venezuela does not seem to be frequently observed in HBV genotype F. This type of infection is frequently associated with variants exhibiting mutations in the surface gene that might be affecting the correct recognition by commercial tests, with precore mutants and with core internal deletions. These variants do not seem to cause severe liver disease, and on the contrary, were found circulating at low viremia.     

Age and sex influence on oxidative damage and functional status in human skeletal muscle

A reduction in muscle mass, with consequent decrease in strength and resistance, is commonly observed with advancing age. In this study we measured markers of oxidative damage to DNA, lipids and proteins, some antioxidant enzyme activities as well Ca²⁺ transport in sarcoplasmic reticulum membranes in muscle biopsies from vastus lateralis of young and elderly healthy subjects of both sexes in order to evaluate the presence of age- and sex- related differences. We found a significant increase in oxidation of DNA and lipids in the elderly group, more evident in males, and a reduction in catalase and glutathione transferase activities. The experiments on Ca²⁺ transport showed an abnormal functional response of aged muscle after exposure to caffeine, which increases the opening of Ca²⁺ channels, as well a reduced activity of the Ca²⁺ pump in elderly males. From these results we conclude that oxidative stress play an important role in muscle aging and that oxidative damage is much more evident in elderly males, suggesting a gender difference maybe related to hormonal factors.This revised version was published online in September 2005 with corrections to the Cover Date.     

DRD4 exon 3 variants are not associated with symptomatology of major psychoses in a German population

We previously reported an association of DRD4 exon 3 long alleles with delusional symptomatology, independently from psychiatric diagnoses [Am. J. Med. Genet. 105 (2001) 283; Psychiatry Res. 80 (1998) 129]. The aim of this investigation was to replicate these results in an independent sample from Germany. We studied 394 subjects, affected by bipolar disorder (n = 32), schizoaffective disorder (n = 45), and schizophrenia (n = 317). All affected subjects were evaluated using the Operational Criteria for Psychotic Illness (OPCRIT) checklist. DRD4 variants were not associated with symptomatology of major psychosis. Our present results, obtained in an independent German sample, did not confirm the association between DRD4 variants and delusional symptomatology. However it should be considered that the original sample included a much higher rate of mood disorders and this could partially explain the discrepancy.     

Intracellular lectin-binding sites in symbiont-bearingCrithidia species

Crithidia oncopelti, C. deanei, andC. desouzai are flagellates of the Trypanosomatidae family that present bacterium-like endosymbionts in their cytoplasm. Direct and indirect lectin-gold labeling techniques were used at the electron microscopic level in Lowicryl K4M-embedded cells to demonstrate the presence of intracellular lectin-binding sites. We used the lectinsUlex europaeus I, Griffonia simplicifolia II, Ricinus communis I, Arachis hypogaea, G. simplicifolia I, Wistaria floribunda, Limulus polyphemus, andCanavalia ensiformis, which recognize -l-fucose, - and -N-acetylglucosamine, -galactose and -N-acetylgalactosamine, -galactose, -galactose, -N-acetylgalactosamine, sialic acid and -d-mannose, and -d-glucose residues, respectively. The nucleus was the cellular structure most frequently labeled by the lectins. The Golgi complex was seldom labeled, whereas the endoplasmic reticulum and the flagellar pocket presented a large number of binding sites. Symbionts had their two unit membranes weakly labeled by the different lectins but displayed no labeling of the space between the membranes.     

Differences in assembly or stability of complex I and other mitochondrial OXPHOS complexes in inherited complex I deficiency

NADH-ubiquinone oxidoreductase (complex I) deficiency is amongst the most encountered defects of the mitochondrial oxidative phosphorylation (OXPHOS) system and is associated with a wide variety of clinical signs and symptoms. Mutations in complex I nuclear structural genes are the most common cause of isolated complex I enzyme deficiencies. The cell biological consequences of such mutations are poorly understood. In this paper we have used blue native electrophoresis in order to study how different nuclear mutations affect the integrity of mitochondrial OXPHOS complexes in fibroblasts from 15 complex I-deficient patients. Our results show an important decrease in the levels of intact complex I in patients harboring mutations in nuclear-encoded complex I subunits, indicating that complex I assembly and/or stability is compromised. Different patterns of low molecular weight subcomplexes are present in these patients, suggesting that the formation of the peripheral arm is affected at an early assembly stage. Mutations in complex I genes can also affect the stability of other mitochondrial complexes, with a specific decrease of fully-assembled complex III in patients with mutations in NDUFS2 and NDUFS4. We have extended this analysis to patients with an isolated complex I deficiency in which no mutations in structural subunits have been found. In this group, we can discriminate between complex I assembly and catalytic defects attending to the fact whether there is a correlation between assembly/activity levels or not. This will help us to point more selectively to candidate genes for pathogenic mutations that could lead to an isolated complex I defect.     

Exclusion of Treacher Collins Franceschetti syndrome in a subject with tetralogy of Fallot and cryptorchidism

Genotyping with flanking DNA markers was used to ascertain Treacher Collins Franceschetti syndrome (TCOF1) in a subject affected by tetralogy of Fallot and cryptorchidism. The proband's family consisted of a father and sister who were affected by the disease, and a healthy mother. Since cardiac malformation and cryptorchidism have been associated with the TCOF1 syndrome, the proband was suspected to be a carrier of the mutated gene. Microsatellite markers D5S527, SPARC and D5S519, which previously mapped the TCOF1 gene within a 2.1-cM interval on chromosome 5 (5q32–33.1), were used to follow the transmission of the TCOf 1 mutated locus. Flanking markers D5S519 and D5S527 were informative and enabled us to exclude inheritance of a TCOF1 mutation to the proband, while showing that cardiac malformation and cryptorchidism were unrelated in mis patient.     

Phosphorylated KDR is expressed in the neoplastic and stromal elements of human renal tumours and shuttles from cell membrane to nucleus

Vascular endothelial growth factor (VEGF)-A is an important angiogenic factor in establishing the vasculature in renal cell carcinomas (RCCs). Since little is known about VEGF signalling in RCCs, the profile of phosphorylated KDR (pKDR) has been investigated and the intracellular location of the receptor has been examined in the present study. Using two monoclonal antibodies raised against the phosphorylated KDR epitopes (Y1059 and Y1214) known to mediate different VEGF functions, together with a commercial anti-KDR antibody and immunohistochemistry, the expression of pKDR was investigated in a series of normal (n = 25) and neoplastic kidneys (n = 54; clear cell n = 35; papillary n = 10; oncocytomas n = 8). pKDR was present in many tissue elements of both normal and neoplastic renal tissues, with strong expression in the cell membrane, cytoplasm, and nuclei of normal kidney and tumour cells, as well as endothelial cells in tumours of all histological types. Patterns and intensity were similar using both anti-pKDR antibodies. There was no significant correlation in clear cell carcinomas between pKDR expression and age (p = 0.57), tumour size (p = 0.2), gender (p = 0.59), grade (p = 0.2) or histological type (p = 0.36). To delineate further the intracellular processing that might account for the cellular distribution, confocal microscopy was also performed. Antibodies to the different phosphorylated epitopes demonstrated different intracellular staining patterns. This study shows that pKDR is present in a wide variety of renal tumours, suggesting that anti-VEGF therapy might have direct effects on tumour cells. It further suggests that cells traffic pKDR depending on the precise KDR tyrosines that are autophosphorylated in a manner that enables receptor activation to result in different functions.     

Immunogenicity and T cell recognition in swine of foot-and-mouth disease virus polymerase 3D

Immunization of domestic pigs with a vaccinia virus (VV) recombinant expressing foot-and-mouth disease virus (FMDV) 3D protein conferred partial protection against challenge with infectious virus. The severity reduction of the clinical symptoms developed by the challenged animals occurred in the absence of significant levels of anti-3D circulating antibodies. This observation suggested that the partial protection observed was mediated by the induction of a 3D-specific cellular immune response. To gain information on the T cell recognition of FMDV 3D protein, we conducted in vitro proliferative assays using lymphocytes from outbred pigs experimentally infected with FMDV and 90 overlapping peptides spanning the complete 3D sequence. The use of pools of two to three peptides allowed the identification of T cell epitopes that were efficiently recognized by lymphocytes from at least four of the five animals analyzed. This recognition was heterotypic because anti-peptide responses increased upon reinfection of animals with a FMDV isolate from a different serotype. The results obtained with individual peptides confirmed the antigenicity observed with peptide pools. Detection of cytokine mRNAs by RT-PCR in lymphocytes stimulated in vitro by individual 3D peptides revealed that IFN-gamma mRNA was the most consistently induced, suggesting that the activated T cells belong to the Th 1 subset. These results indicate that 3D protein contains epitopes that can be efficiently recognized by porcine T lymphocytes from different infected animals, both upon primary and secondary (heterotypic) FMDV infection. These epitopes can extend the repertoire of viral T cell epitopes to be included in subunit and synthetic FMD vaccines.