Chemokine receptor trafficking and viral replication

Summary: Chemokines and chemokine receptors have emerged as crucial factors controlling the development and function of leukocytes. Recent studies have indicated that, in addition to these essential roles, both chemokines and chemokine receptors play critical roles in viral infection and replication. Not only are chemokine receptors key components of the receptor/fusion complexes of primate immunodeficiency viruses, hut chemokines can also influence virus entry and infection. Many viruses, in particular herpesviruses, encode chemokines and chemokine receptors that influence the replication of both the parent virus and other unrelated viruses. The cell surface expression of the chemokine receptors is regulated through their interaction with membrane trafficking pathways, ligands induce receptor internalization and downmodulation through endocytosis, and recycling is regulated within endosomes. Pan of the mechanism through which chemokines protect cells from HIV infection is through ligand-induced internalization of the specific chemokine receptor co-receptors. In addition, mechanisms may exist to regulate the trafficking of newly synthesized receptors to the cell surface. Here we discuss aspects of the mechanisms through which chemokine receptors interact with membrane-trafficking pathways and the influence of these interactions on viral replication.     

Regional over-representations on chromosomes 1q, 3q and 7q in the progression of hepatitis B virus-related hepatocellular carcinoma.

Hepatocellular carcinoma is a highly malignant tumor that is prevalent in Southeast Asia and China, where hepatitis B viral infection is the main etiologic factor. Despite a high incidence of hepatocellular carcinoma developing in patients with viral hepatitis B-induced liver cirrhosis, the molecular events underlying the malignant liver progression remain largely unclear. In an effort to characterize the genetic abnormalities involved in the hepatitis B-related liver carcinogenesis, we performed genome-wide explorations by the technique of comparative genomic hybridization (CGH) on 100 hepatocellular carcinoma tumors that arose from hepatitis B-induced liver cirrhosis. According to the American Joint Committee on Cancer staging, four cases were classified as stage I, 69 as stage II, 23 as stage III and four as stage IV. CGH analysis indicated chromosomal instability in both early (stages I/II) and advanced (stages III/IV) stage tumors, with common gains on 1q, 8q and 17q23-q25, and losses on 4q22-q35, 8p21-p22, 13q14-q21, 16q and 17p identified in both groups (P>0.05). Nevertheless, preferential sites of chromosomal defects in relation to hepatocellular carcinoma progression were also identified. Statistical correlations suggested a higher incidence of regional 1q21-q22, 3q22-q28, 7q21-q22 and 7q34-q36 over-representations in association with the advanced stage tumors (P<0.05). In this study, our novel identification of specific chromosomal aberrations in relation to the advanced stage tumors may represent a first step towards mapping genes linked to the progression of hepatocellular carcinoma.     

Controlled plasmid gene transfer to murine renal carcinoma by hexadecylphosphocholine.

We report here that the anticancer drug hexadecylphosphocholine (HPC) can control plasmid DNA-mediated gene transfer to renal carcinoma following intratumoral administration. Significant improvement of gene expression levels could be achieved depending on HPC dose administered. Optimal concentration of HPC co-injected with plasmid DNA was found to be 0.2% (w/v) showing up to a 10-fold increase in reporter gene expression levels when compared to DNA administered alone. In vivo gene transfer activity of HPC was not affected by the nature of the diluent used, i.e. glucose-based or saline-based isotonic solutions. Although in vitro transfection activity of HPC formulations could not be evidenced, a liposome leakage assay revealed that HPC could significantly destabilize stable lipid membranes suggesting that a possible membrane permeation enhancer activity of HPC combined to the physical stress induced by the intratumor injection may facilitate plasmid DNA entry inside the cells resulting in increased gene expression. HPC/plasmid formulations represent new and attractive non-viral gene delivery systems with potential in cancer gene therapy and vaccination.     

Angiolymphoid Hyperplasia With Eosinophilia: A Classic Clinical Presentation With Histologic Features of Angiosarcoma

BACKGROUND: Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare disease manifested by the proliferation of morphologically distinct endothelial cells. OBJECTIVE: To illustrate by a case report the clinical and varied histopathologic findings of ALHE. METHODS: A 29-year-old woman presented with a clinical picture of ALHE but had several histologic features of angiosarcoma. RESULTS: Management of this patient included repeat biopsies of the lesions, excision of the involved areas, careful histologic examination of the entire specimen, and appropriate follow-up. CONCLUSION: ALHE may present with various histologic features. Knowledge of the spectrum of benign and malignant vascular neoplasms helps manage these challenging cases.     

Adenylate cyclase activity in crude liver membranes during chemical hepatocarcinogenesis in portacaval shunted rats

Hepatocarcinogenesis was initiated in rats with diethylnitrosamine(DEN) followed by a selection with 2-acetylaminofluorene (2-AAF).Portacaval shunt was then performed in order to promote tumordevelopment. Control rats were not submitted to the initiation-selectionprotocol and were sham-operated. In control rats, adenylatecyclase activity from crude liver membranes was stimulated 7-to 8-fold by maximal doses of glucagon (10^–6 M) or guanyl-5'-yl-imidophosphate[Gpp(NH)p] (10^–3 M), and 17-fold by a maximal (10^–5M) dose of forskolin. Guanosine-5'-O-(2-thiodiphosphate) inhibitedthe response to forskolin (–38%) and to low doses of glucagon(–50%). The initiation-selection protocol increased theactivity in basal conditions and in response to various stimuli.The portacaval shunt did not modify the activity of the enzymewith respect to basal activity or the response to glucagon.It significantly decreased the response to Gpp(NH)p (–45%)and to forskolin (–27%). The initiation-selection protocolincreased the basal activity of the enzyme (+150%) and its responseto Gpp(NH)p (+300%). When tumors developed, the activity ofthe cyclase further increased (+200%) and an inhibitory effectof GTP on the hormone-stimulated enzyme appeared (–40%).From these results, it is concluded that the promotion of hepatocarcinogenesisby portacaval shunt is coupled with modifications in the activityof adenylate cyclase in response to glucagon and guanylnucleotides.     

Considering a Simple Strategy for Detection of Women at Risk of Psychological Distress after Childbirth

Abstract: Background : Postpartum depression is a common, severe, yet often undetected condition. Between 10 and 15 percent of new mothers suffer from depressive disorders in the first year after childbirth. The objective of this study was to investigate whether asking women questions about their daily life constituted a useful strategy to detect women at risk of developing psychological distress after childbirth. Methods : A prospective study of 330 first‐ and second‐time mothers was conducted. Structured interviews with women were performed at the maternity unit 1 to 2 days after childbirth, and postal questionnaires were sent to participants 5 months later. An interviewer wrote down her perception of the mood of participants, in the form of three short statements, immediately after the interview. This perception was compared with the score of the woman on the General Health Questionnaire scale, which was included in the 5 months’ questionnaire. Results : The interviewer's perception of women's mood was significantly associated with the score on the General Health Questionnaire scale 5 months later. Multivariate analysis showed that the interviewer's perception of anxiety was a better predictor of postpartum psychological distress at 5 months than women's answers to questions about their mood before pregnancy and 1 to 2 days after delivery. Conclusions : Asking the new mother questions about her private and occupational life can be considered as one of many possible ways to improve the identification of women at risk of developing postpartum depression. (BIRTH 31:1 March 2004)     

Decreased platelet nitric oxide synthase activity and plasma nitric oxide metabolites in major depressive disorder.

BACKGROUND: Major depression (MD) has been associated with increased cardiovascular mortality in patients with coronary heart disease (CHD) and has been described as an independent risk factor for the development of CHD in healthy subjects; however, the mechanism of the association between MD and CHD remains to be determined. Nitric oxide (NO) plays a major role in cardiovascular regulation, and decreased NO production has been associated with several cardiovascular risk factors. We hypothesized that in patients with MD, NO production by both platelets and the endothelium would be reduced when compared with healthy control subjects (HCs). METHODS: Blood samples were obtained from 15 subjects with MD and 16 HCs with no known history of cardiovascular illness. Plasma NO metabolite (NOx) levels were analyzed by chemiluminescence. Platelet endothelial NO synthase (eNOS) activity was examined through the conversion of l-[(14)C]arginine to l-[(14)C]citrulline. RESULTS: The levels of both plasma NOx and platelet eNOS activity were significantly lower in subjects with MD compared with HCs. CONCLUSIONS: These data suggest that decreased NO production by the vascular wall and platelets might contribute to the increased CHD risk observed in patients with MD.     

Inter-laboratory studies for the evaluation of ELISA kits for the detection of chloramphenicol residues in milk and muscle

The use of chloramphenicol in veterinary medicine was banned in the EU in 1994. As the Community Reference Laboratory for antibiotic residues in food of animal origin, one of our functions is to organize inter-laboratory studies. A first inter-laboratory study for the analysis of chloramphenicol (CAP) in milk by ELISA kits was organized in 2001 and a second one for the detection of CAP in pig muscle by ELISA kits in 2002. These studies were intended to allow participants to control their CAP ELISA methods when used routinely and also to compare the performances of various ELISA kits for the detection of chloramphenicol in milk (commercial or in-house kits). In 2001, 15 participants received ten randomly coded frozen milk samples (four blank samples and six spiked milk samples from 0.5 to 5.0 μg/l). In 2002, 20 participants received eight randomly coded frozen muscle samples (two blank samples and six incurred muscle samples from 2.1 to 6.5 μg/kg). They were asked to analyse each sample in triplicate with the ELISA kit of their choice. Different kits from different suppliers were used and compared in the two studies. The results of the two inter-laboratory studies on ELISA kits were satisfactory regarding qualitative results. The global rates of false compliant results of 2.2% for milk and 0.0% for pig muscle samples were lower than 5% whichever kit was used. The global rates of false non-compliant results (16.7% and 10% for milk and muscle respectively) were also satisfactory. The distribution of false non-compliant results depends on the kind of kit used and on the detection limit for milk as well as for muscle. Moreover the sample preparation was very important to avoid false non-compliant results. Finally, this study demonstrates that ELISA kits for chloramphenicol in milk and muscle globally show good repeatability and accuracy. So these kits could be considered as suitable tests for screening purposes.