Heterogeneity of hepatitis C virus genotype 4 strains circulating in south-western France

Hepatitis C virus (HCV) is a major cause of liver disease. Knowledge of HCV variability is crucial for clinical and epidemiological analysis. HCV genotype 4 (HCV-4) has become increasingly prevalent in European countries, including France, in recent years. The present study investigates the heterogeneity of HCV-4 in south-western France by phylogenetic analysis of NS5B sequences from 166 patients. The E2 region of 90 strains was also analysed. Genotype 4 accounts for 7·4 % of HCV infections in this area. Analysis of the NS5B region revealed 12 subtypes and the NS5B and E2 phylogeny data were congruent, except for one strain. The epidemiological data indicated two main groups of patients. One included intravenous drug users (IVDUs) of French origin, who were infected by homogeneous strains of subtypes 4a or 4d. The second group comprised non-IVDU patients who were infected with heterogeneous strains. This group was subdivided into patients of French origin, who were infected with eight subtypes, and patients from non-European countries (Central Africa or the Middle East), who were mainly infected with 4f, 4k, 4r and other subtypes; they showed the greatest genetic heterogeneity. This study of a large cohort of patients shows the great diversity of HCV-4 strains, and that these subtypes have spread differently.

Mice with the deleted neurofilament of low molecular weight (Nefl) gene: 2. Effects on motor functions and spatial orientation

Mice with a null mutation of the Nefl gene were compared with normal controls in tests of motor activity, equilibrium, and spatial orientation. Despite a normal capacity to ambulate, NFL -/- mice had fewer rears in an open field, crossed fewer segments on stationary beams, and fell more frequently when suspended on a horizontal bar. In addition, the distance swum before reaching the escape platform was greater in NFL -/- mice than in controls during acquisition of place learning in the Morris water maze at the start of training. The motor impairments were linearly correlated with increased cytochrome oxidase activity seen in cerebellum and brainstem. These results indicate that, as early as 6 months, depletion of the NFL protein is sufficient to cause mild sensorimotor dysfunctions and spatial deficits, but without overt signs of paresis.

Distribution and heterogeneity of hepatitis C genotypes in hepatitis patients in Cameroon

Hepatitis C virus infects humans world-wide. The virus genome varies greatly and it has several genotypes. HCV infection is highly prevalent in Central Africa and Cameroon. Initial studies on the genetic variability of HCV showed infection with HCV genotypes 1, 2, and 4. We have now sequenced the NS5b and E2 regions of 156 HCV isolates collected from patients presenting for diagnosis in Yaounde and used the data to describe the distribution of HCV genotypes and subtypes in patients with hepatitis in Cameroon. Genotype 1 was more frequent than Genotypes 4 and 2. Genotypes 1 and 4 were highly heterogeneous, containing many subtypes described previously (1b, 1c, 1e, 1h, 1l, 4f, 4t, 4p, 4k) and unsubtyped groups. There was a systematic phylogenetic concordance between NS5b and E2 sequence clustering. The Genotype 2 sequences did not vary. Neither subject age nor gender influenced HCV distribution. HCV Genotypes 1 and 4 are very heterogeneous in Cameroon, perhaps due to ancient infections. The homogeneity of HCV Genotype 2 indicates its more recent introduction from western Africa.

Evolution of hepatitis C virus quasispecies during therapy with IL2 combinated to alpha interferon and ribavirin

This study analyses the impact of interleukin 2 (IL2) combined with alpha interferon (IFN-alpha) and ribavirin on the heterogeneity of hepatitis C virus (HCV). We studied 10 patients who took part in a clinical trial that assessed the effects of retreatment with IL2, IFN-alpha and ribavirin in patients who failed to clear the virus after a previous bitherapy. The heterogeneity of HCV quasispecies was assessed by cloning and sequencing the hypervariable region 1 (HVR1) in samples obtained at baseline (W0), after 12 weeks of treatment with IFN-alpha and ribavirin (W12), after a cycle of administration of IL2 in combination with the classical bitherapy (W21 and W24) in the eight patients who failed to clear the virus under treatment. The mean viral load at W21 and at W24 was not different from that at W12. The heterogeneity of HVR1 quasispecies after the administration of IL2 was not different from that at baseline or after 12 weeks of bitherapy. Furthermore, the proportion of nonsynonymous substitutions was unchanged after the IL2 cycles. Thus, the efficacy of the tritherapy with IL2, IFN-alpha and ribavirin is similar to that of the classical bitherapy. Treatment with IL2 in combination with IFN-alpha and ribavirin had no effect on the selective pressure on HCV quasispecies. IL2 is not the best option to treat hepatitis C.

Mice with the deleted neurofilament of low-molecular-weight (Nefl) gene: 1. Effects on regional brain metabolism

Neuronal intermediate filaments consist of the NFL subunit linked with NFM and NFH, and their alterations have been proposed as a pathogenesic cause in motor neuron diseases. Depletion of the Nefl gene in mice mimicks the reduced NFL mRNA levels seen in amyotrophic lateral sclerosis and causes perikaryal accumulation of neurofilament proteins and axonal hypotrophy in motoneurons. NFL -/- mice were evaluated for regional brain metabolism by means of quantitative histochemical estimation of cytochrome oxidase (COx) activity. The NFL null mice displayed enzymatic activity alterations in numerous hindbrain regions, mainly the cerebellum, connected regions of the brainstem (red nucleus, vestibular nuclei, and reticular formation), and cranial nerve nuclei. All of the affected regions presented elevated COx activity, except for the Purkinje cells of the cerebellum and the magnocellular red nucleus, where enzymatic activity was lower. NFL-disrupted mice displayed functional alterations in brainstem sensorimotor regions affected in amyotrophic lateral sclerosis.

Efficient and sensitive detection of residues of nine coccidiostats in egg and muscle by liquid chromatography–electrospray tandem mass spectrometry

We present a method based on electrospray liquid chromatography tandem mass spectrometry (LC-MS/MS) for determining in muscle and eggs the following nine coccidiostats: halofuginone, diclazuril, dinitrocarbanilide (the main metabolite of nicarbazin), robenidine, monensin, lasalocid, narasin, salinomycin, and maduramicin. Dinitrocarbanilide-d8, nigericin, and diclazuril-bis were used as internal standards. The method uses extraction in acetonitrile followed by a clean-up on an SiOH solid-phase extraction column. High-performance liquid chromatography (HPLC) separation was performed on a Purospher C(18) column (125 mm x 3 mm i.d.) protected by a guard column, the mobile phase being a water-acetonitrile gradient (each gradient component containing 0.1% formic acid) at a flow rate of 1 ml min(-1). For unequivocal identification of each analyte, two ions were detected and chosen for multiple reaction monitoring (MRM). Validation was carried out on spiked muscle and egg samples. The method described meets all the criteria of Decision 2002/657/EC and is easy to use in routine analysis. Validation results are presented with the measured CCalpha and CCbeta values. This whole method allows extraction and analysis of up to 24 samples per day.

Hepatitis E in the south west of France in individuals who have never visited an endemic area

A total of 431 consecutive patients from the Midi Pyrenees area with acute hepatitis with unknown etiology in 2001-2002 were tested for the presence of immunoglobulin G-class (IgG) anti-hepatitis E virus (HEV) antibodies. Forty-six (10.7%) had anti-HEV IgG, and the results were questionable for a further 17 (3.9%). Real time PCR based on TaqMan detection was used to identify HEV genome fragments in the serum of patients with positive or questionable anti-HEV serology. HEV RNA was found in 25.4% of cases. All amplification products were sequenced and analyzed. Phylogenetic analysis revealed that all the strains were genotype 3. In conclusion, virological and epidemiological data indicate that genotype 3 viruses are circulating in the south west part of France (Midi-Pyrenees) in patients with acute hepatitis and who have not visited recently areas in which HEV is endemic.

Human chorionic gonadotropin and growth factors at the embryonic-endometrial interface control leukemia inhibitory factor (LIF) and interleukin 6 (IL-6) secretion by human endometrial epithelium

BACKGROUND

The elucidation of the molecular mechanisms by which the embryo contributes to its implantation is an area of extensive research. The main objective of this study was to investigate the pattern of leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) secretion by human endometrial epithelium, and their regulation by human chorionic gonadotropin (hCG) and other growth factors present at the embryonic-endometrial interface.

METHODS

Endometrial epithelial cells (EEC) were isolated from biopsies collected at both proliferative and secretory phases of fertile women.

RESULTS

HCG (1-50 IU/ml) increased LIF secretion by EEC cultures derived from follicular phase (up to 285+/-75%) or from secretory phase (up to 212+/-16%). In contrast, hCG reduced IL-6 secretion by EEC in both phases. The hCG/LH receptor gene was transcribed by EEC as evidenced by RT-PCR. Insulin-like growth factors 1 and 2 increased LIF secretion by EEC. Transforming growth factor beta1 stimulated LIF and reduced IL-6 secretion.

CONCLUSIONS

Through hCG, the blastocyst may be involved in the control of its implantation (via an increase of proimplantatory LIF) and tolerance (via an inhibition of proinflammatory IL-6). Other growth factors present at the embryonic-endometrial interface are also involved in the control of LIF and IL-6 endometrial secretion.

Electrochemical impedance spectroscopy and electron spin resonance characterization of the conductive state of parasexiphenylene electrochemically intercalated with sodium

The electrochemical intercalation of sodium ions into parasexiphenylene (PSP) was studied by electron spin resonance (ESR) and electrochemical impedance spectroscopy (EIS). These complementary techniques give informations about the conduction state of the host material as a function of the doping rate both in the intercalation and deintercalation processes. These data were compared to the previous works concerning the intercalation of alkaline ions into polyparaphenylene (PPP).

Semiconducting surface reconstructions of p-type Si(100) substrates at 5 K

We report scanning tunneling microscopy (STM) studies of the technologically important Si(100) surface that reveal at 5 K the coexistence of stable surface domains consisting of the p(2 x 1) reconstruction along with the c(4 x 2) and p(2 x 2) reconstructions. Using highly resolved tunneling spectroscopic measurements and tight binding calculations, we prove that the p(2 x 1) reconstruction is asymmetric and determine the mechanism that enables the contrast variation observed in the formation of the bias-dependent STM images for this reconstruction.

Non-esterified fatty acids are deleterious for human pancreatic islet function at physiological glucose concentration

AIMS/HYPOTHESIS

Whether excess glucose (glucotoxicity) and excess non-esterified fatty acids (lipotoxicity) act synergistically or separately to alter beta-cell function on Type 2 diabetes remains controversial. We examined the influence of non-esterified fatty acids, with or without concomitant increased glucose concentrations, on human islet function and on the expression of genes involved in lipid metabolism.

METHODS

Human islets isolated from non-diabetic and non-obese donors were cultured with 5.5, 16 or 30 mmol/l glucose, and when appropriate with 1 or 2 mmol/l non-esterified fatty acids. After 48 h, glucose-stimulated insulin secretion, insulin content, triglyceride content and expression of different genes were evaluated.

RESULTS

Non-esterified fatty acids decreased glucose-stimulated insulin secretion, insulin content and increased triglyceride content of human isolated islets, independently from the deleterious effect of glucose. Increased glucose concentrations also decreased glucose-stimulated insulin secretion and insulin content, but had no influence on triglyceride content. Glucose-stimulated insulin secretion of islets appeared to be significantly correlated with their triglyceride content. Glucose and non-esterified fatty acids modified the gene expression of carnitine palmitoyltransferase-I, acetyl-CoA carboxylase, acyl-CoA oxidase and uncoupling protein 2.

CONCLUSION/INTERPRETATION

In our model of isolated human islets, increased glucose and non-esterified fatty acids separately reproduced the two major beta-cell alterations observed in vivo, i.e. loss of glucose-stimulated insulin secretion and reduction in islet insulin content. Our results also suggest that this deleterious effect was, at least in part, mediated by modifications in lipid metabolism gene expression.

High rate of hepatitis C virus infection and predominance of genotype 4 among elderly inhabitants of a remote village of the rain forest of South Cameroon

To determine the prevalence of hepatitis C virus (HCV) infection and genotype distribution in a rural isolated area of Central Africa, plasma of 409 Bantous (mean age, 32 years; range, 2-78 years) living in a remote village of the rain forest of Southern Cameroon was screened for anti-HCV antibodies. HCV seropositive samples were also subjected to qualitative detection of viral RNA. HCV antibodies were detected in 70 (17.1%) individuals, 48 (68.8%) of whom had detectable viremia. The seroprevalence did not differ by gender (P = 0.37), but increased significantly with age (P < 0.05), with a strong increase in the oldest age groups. Indeed, nearly one-half (48%) of the adults >50 years old were HCV seropositive. The characterization of the viral genotypes indicated that most of the HCV strains were of genotype 4 (76%), while genotype 2 (16%), and 1 (8%) were marginally represented. The results suggest a cohort effect with an old, possibly iatrogenic, group exposure rather than a continuous exposure. A more in-depth population-based epidemiological study is needed to address this issue further.

Anticorps anti-ovaires et fécondation in vitro : cause ou conséquence ?

OBJECTIVES

To assess anti-ovarian antibodies (AOA) in serum samples at various times of in vitro fertilization (IVF) attempts to determine whether ovarian stimulation could result in the production of such autoantibodies in women.

PATIENTS AND METHODS

Prospective study on 134 patients and 138 IVF cycles using a classical long protocol. For each attempt, four serum samples were obtained, respectively, at the onset of downrelation (S1), end of downregulation (S13), after 7 days of follicular stimulation (S21) and the day of follicular puncture (SP). Five hundred and fifty two samples were tested with an enzyme-linked immunosorbent assay for three isotypes (IgG, IgA, IgM) of AOA.

RESULTS

In the whole group, mean concentrations of AOA for each isotype were compared group by group: S1-S13, S1-S21, S1-SP, S13-S21, S13-SP, S21-SP. Not any significant difference was observed whatever the isotype considered.

DISCUSSION AND CONCLUSION

This study shows the absence of influence of endogenous or exogenous ovarian stimulation by gonadotropins on anti-ovarian autoimmunity.

Evidence of a limited contribution of feto-maternal interactions to trophoblast differentiation along the invasive pathway

Trophoblast differentiation is a key event in human placental development. During extravillous trophoblast (EVT) differentiation, stem cells from the anchoring villi detach from their basement membrane and proliferate to form aggregates called trophoblast cell columns (TCCs). They subsequently invade the decidua and differentiate into interstitial and endovascular trophoblasts. The influence of the decidua on EVT differentiation is controversial. We therefore compared the pattern of trophoblast differentiation marker expression in viable intrauterine and tubal pregnancies, as decidual cell markers (prolactin [PRL] and insulin-like growth factor binding Protein-1 [IGFBP1]) were only expressed in endometrial implantation sites. Extravillous trophoblast differentiation in anchoring villi from uterine and ectopic pregnancies exhibited a comparable phenotypical switch: alpha6 integrin subunit, E-cadherin, EGF receptor, Ki 67 and connexin 40 were localized in the proximal part of the TCC, while alpha5beta1 and alpha1 integrins, c-erb B2, hPL and HLA-G were expressed by invasive cytotrophoblasts. The cyclin-dependent kinase inhibitors p16 and p57 were mainly detected in invasive cytotrophoblasts some distance from the columns. However, the TCC was markedly longer in tubal pregnancy than in intrauterine pregnancy. These findings suggest that the decidua is not necessary to trigger EVT invasion, but that it is likely to limit the extent of the TCC and to accelerate the onset of EVT migration.

Twin pregnancy obtained with frozen-thawed embryos after in vitro maturation in a patient with polycystic ovarian syndrome

PURPOSE

A twin pregnancy was obtained in a patient with polycystic ovary syndrome after the transfer of three in vitro maturation-derived day 3 embryos that has been frozen and thawed.

METHODS

The patient had received mild hMG stimulation followed by hCG injection. After culture for 24-48 h, mature oocytes were fertilized by ICSI. Embryos were cultured until day 3; supernumerary embryos were cryopreserved using a slow protocol.

RESULTS

Among 15 nonatretic oocytes, 9 matured, 8 were fertilized. Four embryos were transferred but they did not implant. The subsequent transfer of three frozen-thawed embryos resulted in the delivery of two healthy girls.

CONCLUSIONS

These results indicate that a pregnancy could be obtained with in vitro maturation-derived day-3 frozen-thawed embryos.

Raman spectroelectrochemical study of sodium intercalation into poly(p-phenylene)

The structural defects formed along the polymer chain during the electrochemical intercalation of sodium into polyparaphenylene (PPP) were investigated by in situ FT Raman measurements with an excitation wavelength of 1064 nm. Our Raman data are compared with those obtained for PPP and its oligomers intercalated with Na(+) ions by chemical ways. The coexistence of polarons and bipolarons is observed in the early stages of the intercalation process. When the doping level increases polarons are transformed to bipolarons, then in the highly intercalated sample (corresponding to a composition close to Na(0.5)(C(6)H(4))), bipolarons are the main structural defects. This evolution, which is reversible, is in accordance with the electron spin resonance (ESR) data of PPP intercalated with sodium ions in the same experimental conditions.

Evolution of hepatitis C virus quasispecies in renal transplant patients with de novo glomerulonephritis

Long-term renal allograft survival in kidney transplant recipients infected by hepatitis C virus (HCV) may be influenced by the occurrence of de novo glomerulopathy associated with this virus. Therefore, we studied the evolution of HCV quasispecies in kidney transplant recipients infected by HCV with or without de novo glomerulopathy. The hypervariable region 1 (HVR-1) of the virus envelope was analyzed by cloning and sequencing 20 clones per sample to assess complexity and diversity from six kidney transplant patients who developed de novo glomerulopathy (group I) matched to six kidney transplant recipients without glomerular disease (group II), according to age, time since renal transplantation, and HCV genotype. Two sera were analyzed for each patient: one at the time of renal transplantation and the other at the time of appearance of de novo glomerulopathy, or after a similar duration since transplantation in group II. Overall, there was a significant increase of HCV viremia after the transplantation. This increase did not differ significantly between group I (+0.5 log copies/ml) and group II patients (+1 log copies/ml). The intersample diversity of HCV was similar in the two groups. Complexity and viral diversity were also similar at the time of transplantation. By contrast, complexity, diversity, and the proportion of nonsynonymous substitutions per nonsynonymous site were significantly higher after transplantation in group I patients. Our findings suggest a higher immune response and/or a particular cytokine production in patients developing de novo glomerulopathy rather than a direct effect of HCV on renal cells.

On-line measurement of texture, thickness and plastic strain ratio using laser-ultrasound resonance spectroscopy

Laser-ultrasound resonance spectroscopy, a non-contact ultrasonic technique, was used to determine reliably and rapidly the crystallographic texture, the average plastic strain ratio, and the thickness of sheet metal on the production line. As with laser-ultrasonics, a short laser pulse is used to generate a wide-band pulse of ultrasound and a laser interferometer is used for its detection. In this paper, a large number of echoes are collected and analyzed together using Fourier techniques to measure the natural resonance frequencies in the thickness of the sheet. One longitudinal and two shear resonance frequencies were measured together with their harmonics. From these frequencies, two crystallographic orientation distribution coefficients, W(400) and W(420), are obtained, as well as a highly accurate measurement of the sheet thickness that is corrected for changes in ultrasonic velocity caused by texture variations. Using these coefficients, the average and in-plane twofold and fourfold variations of the plastic strain ratio, respectively r delta(2)r, and delta(4)r, can be evaluated. These parameters are indications of the formability of metals sheets, which is of industrial interest. Measurements on 1 mm thick, low carbon steel sheets have shown the following measurement accuracies: r to within +/-0.08, delta(2)r, and delta(4)r to within +/-0.1, and thickness to better than +/-1 microm. On-line tests at LTV Steel Company showed that the sensitivity of the apparatus is sufficient to detect systematic variations in texture along the length of similar production coils and that the on-line repeatability for r was of order +/-0.02.

[Thiazolidinediones in type 2 diabetes. Role of peroxisome proliferator-activated receptor gamma (PPARgamma)]

Thiazolidinediones (TZDs) form a new class of oral antidiabetic agents. They improve insulin sensitivity and reduce glycemia, lipidemia and insulinemia in patients with type 2 diabetes. Their mechanism is original, since they activate the nuclear receptor Peroxisome Proliferator-Activated Receptor gamma (PPARgamma), altering the expression of genes involved in glucose and lipid homeostasis. Stimulating PPARgamma improves insulin sensitivity via several mechanisms: 1) it raises the expression of GLUT4 glucose transporter; 2) it regulates release of adipocyte-derived signaling factors that affect insulin sensitivity in muscle, and 3) it contributes to a turn-over in adipose tissue, inducing the production of smaller, more insulin sensitive adipocytes. TZDs also affect free fatty acids (FFA) lipotoxicity on islets, improving pancreatic B-cell function. In addition, triglycerides and FFA levels are lowered by TZDs. Two TZDs, rosiglitazone and pioglitazone, have recently obtained the European commercial licence, but their use is restricted to the association with metformin or sulfonylureas. At the moment, they are indicated in type 2 diabetes but could be of interest in a broader array of diseases related to insulin resistance. As for side effects, rosiglitazone and pioglitazone may cause increased plasma volume, edema and dose-related weight gain. TZDs offer an attractive option in the treatment of type 2 diabetes, though it may be too soon to determine if they prevent vascular complications, as do other oral antidiabetic agents. An important issue for the future will be to assess the influence of weight gain in the long time.

Genetic heterogeneity of the envelope 2 gene and eradication of hepatitis C virus after a second course of interferon-alpha

The heterogeneity of the envelope 2 (E2) gene of the hepatitis C virus (HCV) was involved in the sensitivity of HCV to interferon-alpha (IFN-alpha). To assess the factors leading to virus eradication by IFN-alpha, patients whose first treatment by IFN-alpha failed and who had virus eradication after a second treatment were studied. These patients were paired with subjects in whom both treatments failed. The phosphorylation homology domain of the E2 gene (E2-PHD) had no sequence variation between the two stages in both groups of patients. Therefore, this region has no clinical predictive value within a specific genotype. The hypervariable region 1 (HVR1) was analyzed by cloning and sequencing 20 clones per sample. Comparison of samples showed that the change in quasispecies induced by the first IFN-alpha therapy could be associated with virus elimination obtained after a second treatment. The greater proportion of nonsynonymous mutations that was noted before the second treatment in responders suggest that pretherapeutic immune response is a major factor determining virus elimination and that the immune status of these patients changed between the first and the second treatment.