Reporter Cell Lines to Monitor Steroid and Antisteroid Potential of Environmental Samples

In order to monitor the (anti)steroid activity of environmental samples, we established stable cell lines expressing luciferase under the control of estrogens, androgens, progestives and glucocorticoids. The breast cancer MCF-7 cells which express the estrogen receptor (ER), the glucocorticoid receptor (GR) and the progesterone receptor (PR) were transfected by an estrogen (ERE-Glob-Luc) or a glucocorticoid/progestin/androgen (MMTV-Luc) regulated luciferase plasmid in order to enable the detection of compounds which bind both ER, PR and GR (MELN and MMLN cells). Human prostatic cells PC3 were stably transfected by both an androgen receptor gene and the MMTV-luciferase plasmid (PALM cells). These three cellular models were validated as tools to check the estrogenic, progestive, glucocorticoid and androgenic activities using several potential xenohormones and environmental samples. As these environmental samples were fractionated after solid phase extraction to isolate active compounds, we used these cellular models to monitor the different fractions. In the estrogenic model mid-polar fractions of environmental samples were found active while in the androgenic model, the same fractions had antagonist activity.     

Low posttrauma GABA plasma levels as a predictive factor in the development of acute posttraumatic stress disorder.

BACKGROUND: Gamma amino-butyric acid (GABA) regulates the intensity and the duration of the central hyperadrenergic response in times of high stress and has been negatively associated with anxiety, depression, and sleep problems. We hypothesized that individuals with low plasma GABA levels may be more prone to develop posttraumatic stress disorder (PTSD) in the aftermath of trauma exposure. METHODS: To test this hypothesis, we measured plasma GABA levels in a population of 108 road traffic accident victims on arrival at a traumatology department and assessed them for PTSD 6 weeks later. RESULTS: The mean GABA level (nmol/mL) in the PTSD group (n = 55; M =.20; SD =.08) was significantly lower compared with members of the trauma-exposed group who did not develop PTSD [n = 17; M =.30; SD =.09), t(70) = 3.94, p =.0002]. CONCLUSIONS: Provided that GABA levels in the brain are genetically predetermined, our results would suggest that individuals with low plasma GABA levels are premorbidly more vulnerable to stress-related disorders such as acute PTSD. If replicated, plasma GABA levels measured in the aftermath of trauma exposure might help to identify individuals at high risk for developing PTSD.     

Stepwise occurrence of a complex unbalanced translocation in neuroblastoma leading to insertion of a telomere sequence and late chromosome 17q gain

In neuroblastoma, the most frequent genetic alterations are unbalanced translocations involving chromosome 17. To gain insights into these rearrangements, we have characterized a previously identified der(1)t(1;17) of the CLB-Bar cell line. The 17q breakpoint was mapped by FISH. Subsequently, a rearranged fragment was identified by Southern analysis, cloned in a lambda vector and sequenced. The chromosome rearrangement is more complex than expected due to the presence of an interstitial 4p telomeric sequence between chromosome 1p and 17q. Three different genes, which may play a role in neuroblastoma development, are disrupted by the translocation breakpoints. Indeed, the 3'UTR of the PIP5K2B gene on chromosome 17q is directly fused to the (TTAGGG)n repeat of the chromosome 4p telomere, and the (1;4) fusion disrupts the MACF1 (microtubule-actin crosslinking factor 1) and POLN genes, respectively. Interestingly, the (1;4) fusion was present at diagnosis and at relapse, whereas the (4;17) fusion was detected at relapse only, leading to a secondary 17q gain confirmed by array CGH therefore indicating that 17q gain may not be a primary event in neuroblastoma. Finally, screening of a panel of neuroblastoma cell lines identified interstitial telomeric sequences in three other cases, suggesting that this may be a recurrent mechanism leading to unbalanced translocations in neuroblastoma.     

Diagnostic accuracy of the fibrotest in hemodialysis and renal transplant patients with chronic hepatitis C virus

BACKGROUND: An accurate diagnosis of hepatitis C virus (HCV)-related liver lesions is mandatory in dialysis patients and kidney recipients to better define the treatment of and contraindications to kidney transplantation. The aim of this study was to assess the diagnostic accuracy of the fibrotest (a noninvasive method to assess liver fibrosis in HCV on a scale from 0 to 1) in hemodialysis and renal transplant patients infected by chronic HCV. METHODS: In all, 110 patients with biopsy-proven HCV (60 renal transplant recipients and 50 hemodialysis patients), determined using the METAVIR scoring system, were studied. RESULTS: Forty-six percent of patients had fibrosis > or =F2. A positive predictive value of a score >0.6 for the presence of significant fibrosis by comparison with liver biopsy was 71%, and an negative predictive value of < 0.2 for excluding significant fibrosis was 77%, respectively. The areas under the ROC curves for the diagnosis of significant fibrosis were 0.66, 0.47, and 0.71 in the global population, hemodialysis patients, and renal transplant patients, respectively. In all, 75% of patients were correctly classified using the fibrotest. If biopsy was restricted to scores in the intermediate range (< 0.6 and >0.2), the index could reduce the indication for biopsy by 47%. The results did not differ significantly in hemodialysis and renal transplant patients. CONCLUSION: The fibrotest has a diagnostic value in hemodialysis and renal transplant patients which is similar to that reported in the general population (75%) and its use could avoid 32% of liver biopsies if it were interpreted in detail in nephrology patients.     

Efficacy and safety of adefovir dipivoxil in kidney recipients, hemodialysis patients, and patients with renal insufficiency

BACKGROUND: This study analyzes the biochemical, serological, and virological efficacy and the safety of adefovir dipivoxil in patients with renal disturbances. METHODS: Twelve patients with lamivudine-resistant hepatitis B virus (HBV) chronic infection were treated for a median time of 15 (3-19) months. The daily dosage was 10 mg initially and then adjusted according to renal function. RESULTS: Median (range) ALT values remained stable: 55 (13-117) and 37 (17-266) UI/L. After the 12th month, the median decline in serum HBV DNA was from 8.76 (6.3-9.7) to 2.97 (1.15-5.65) log10 Eq/ml (median decline of -5.5 log10). No virologic breakthrough was observed. One of the six HBeAg-positive patients lost HBe Ag but without HBe seroconversion; none had HBs Ag loss. There were no significant clinical and biochemical adverse effects. In the 11 nonhemodialysed patients, the creatinine clearance significantly improved from 70 (30-100) to 88 (38-125) ml/mn (P=0.01) and the mean serum creatinine levels increased only slightly from 114 (91-839) to 130 (81-561) micromol/ml (NS). Serum phosphorus remained stable. The urinary level of protein decreased from 0.16 (0.08-8.63) to 0.12 (0.01-0.74) g/day (NS). CONCLUSIONS: Adefovir dipivoxil is safe for the treatment of chronic hepatitis B in patients with varying degrees of renal dysfunction and lamivudine-resistant HBV and results in biochemical and virological efficacy similar to that reported in the general population.     

Clinical and biological features associated with taste loss in internal medicine patients. A cross-sectional study of 100 cases

Which are the main features associated with taste loss in patients exposed to a wide range of drugs and diseases? In 100 consecutive patients admitted to a ward of internal medicine, we assessed taste complaints, performance status, alcohol and tobacco consumptions, diseases, drugs and laboratory data, measuring the electrical taste threshold as primary outcome. After adjusting for age, taste thresholds were not associated with sex, body mass index, tobacco, thrush, drugs, aliageusia and phantogeusia. Features associated with threshold increase included alcohol intake>or=10 gd-1, impaired performance status, complaint of taste loss, atrophic glossitis, cerebral disease, and an erythrocyte mean corpuscular volume. A multivariate analysis identified age, alcohol intake, complaint of loss or altered taste, mean corpuscular volume, and performance status as independent factors associated with taste loss. Inpatients may be screened for taste loss by a few features, to identify those for whom a nutritional intervention should be focused.     

Discovery of pyrimidyl-5-hydroxamic acids as new potent histone deacetylase inhibitors

A series of pyrimidyl-5-hydroxamic acids was prepared for evaluation as inhibitors of histone deacetylase (HDAC). Amino-2-pyrimidinyl can be used as a linker to provide HDAC inhibitors of good enzymatic potency.     

DNA vaccination for the priming of neutralizing antibodies against non-immunogenic STa enterotoxin from enterotoxigenic Escherichia coli

In order to test the use of DNA vaccination for its capacity to induce antibodies against the non-immunogenic heat-stable enterotoxin STa from Escherichia coli, BALB/c mice were immunized with plasmid DNA encoding hybrid proteins made by the insertion of wild type STa or insertion of the Cys6Ala, Cys17Ala and Cys6Ala-Cys17Ala STa mutants at positions 195 or 216 of the TEM-1 beta-lactamase. No STa specific antibodies could be detected after three plasmid injections, but a subsequent boost with native STa peptide was capable of inducing low levels of neutralizing antibodies, as tested in the suckling mouse assay. Highest STa specific responses were found in mice primed with the double mutated STa inserted in position 195. This plasmid induced highest T-cell responses to the TEM-1 protein, indicating that priming of helper T-cell responses to the carrier protein was essential. Mixed IgG1/IgG2a isotypes also reflected this T helper 1 type priming. Moreover, insertion into loop A of the TEM-1 carrier may be more suitable than insertion into loop B, because of reduced competition between carrier and hapten B cell responses.