St. Cercet. Virusol. 36 (2) 2006

Contents

• 77 - Cytomegalovirus and immunogenetic involvement in graft rejection - Irina Alexiu [more...]

  “Åžtefan S. Nicolau” Institute of Virology, Bucharest, Romania
  Abstract. There are three hypotesis concerning cytomegalovirus(cmv) involvement in graft rejection: 1. a cause-effect relationship cmv-graft, 2. a cause –effect relashioship graft-cmv, and 3. no association between the two issues. The mechanisms proposed for graft vascular damage induced by cmv infection, lies on endothelial cells injury through different proinflammatory ways or by cross-reactive antibodies. IL10 homologue expressed by cmv reveal an anti-inflammatory effect that cmv produces. Human beings differ în cytokine titer în a wide range, but they can be grouped in high-producers, medium producers and low-producers. A recent revealed mechanism involved în these differencies between people is represented by single nucleotide polymorphisms (SNPs) or by microsatelite polymorphisms. The presence of SNPs at certain positions in IL6, IL10, TNFa, IFNg genes seems to facilitate or to diminish graft rejection and viral infection recurrences.

  Keywords: cmv, graft rejection, snp, phenotype.

• 85 - Anomalies of lipid metabolism in hiv positive patients under antiretroviral treatment - Loredana Manolescu, Camelia Sultana, Simona Ruţă [more...]

  Institute of Virology „St S Nicolau”, UMF „C Davila”, Bucharest, Romania
  Abstract. The extended use of highly active antiretroviral therapy (HAART) in the treatment of HIV infection implies also to monitor the antiretroviral toxicity on the long run. The present study evaluates the incidence of lipid anomalies during the antiretroviral therapy in HIV infected adolescents, long term survivors, treated with multiple drug combinations. Our results indicate the fact that the use on log term of boosted ritonavir for other protease inhibitors conducts at important alterations in cholesterol and triglycerides values. So, the percent of the patients with values over the normal limit has raised during a year of treatment from 6.8% initially to 19,5% (p=0,02) for cholesterol; respective from 51% to 57% for triglycerides. The small values of the cholesterol associated with high values of triglycerides define the patients with severe prognosis known as rapid progressors. Dislypidemia can be at least partially attributed to the mitochondrial dysfunction determined by the protease inhibitors and not to the metabolic alteration induced by the long term HIV infection.

  Keywords: antiretroviral therapy, lipodystrophy, seric cholesterol, seric triglicerides.

• 93 - Neurotrophins, trophic elements in viral neuroinflamation - Daniela Păsărică¹  Mihaela Gheorghiu¹, M. Stoian² [more...]

  ¹Carol Davila” University of Medicine and Pharmacy, Pathophysiology and Immunology Department, Bucharest, Romania
  ²“St. S.Nicolau” Institute of Virology, Bucharest, Romania
  Abstract. Neural growth factors can be produced by CNS cells in response to cell injury from viral infection. These factors include neurotrophic /angiotrophic factors and among others. Members of neurotrophic family include Nerve growth factor (NGF); Brain-derived neurotrophic factor ( BDNF); Neurotrophin 3 (NT-3) and Neurotrophin 4/5 ( NT4/5). They are produced by neurons and glial cells to promote neuronal survival and they may also provide neuronal protection against toxic neuroimmune components such as cytokine, chemokine and harmful viral products. Interaction among trophic factors and neuroimmune response components contribute to neurons survival and to mentain blood brain barrier (BBB) integrity during viral neuroinflamation. It has been proposed that neurotrophins play a role in modulating the immune response.

  Keywords: Neurotrophins, viral neuroinflamation.

• 107 - HPV virus – marker for metastatic adenopathia of laryngeal/ pharyngeal cancers - Coralia Bleotu¹, Gabriela Anton¹, Adriana Plesa¹, Liliana Popescu², Mihaela Chivu¹, Luminita Welt², Raluca DrăguÅŸin², Laura Dragomir¹, C.R.Popescu², Anca Botezatu¹, C.Cernescu¹ [more...]

  ¹„Åžtefan S. Nicolau” Institute of Virology, Bucharest, Romania
  ²ColÅ£ea Clinic Hospital, Bucharest, Romania
  Abstract. Laryngeal/pharyngeal cancers are frequent in population and have been associated with high mortality. In addition, cervical lymph nodes implications represent the most important prognostic factor in squamous cell carcinoma of head and neck cancer. The precisely etiology and mechanisms of progression are not clear, but implications of human papillomaviruses in squamous cell carcinoma of laryngeal/pharyngeal cancers was suggested. Our aim was to detect HPV in regional nodes of cancer with laryngeal / pharyngeal localization. HPV DNA was detected in local lymph nodes from patients that present HPV virus in tumoral fragment. All local lymph nodes with metastases hold DNA HPV 16. In 20% reactive lymph nodes were not relieved HPV16. Our results sustain that detection of HPV DNA in regional lymph nodes is a „surrogate marker” of metastasis when extension of metastasis (disease) can not be estimated, and this is very important for management of cancer with laryngeal/pharyngeal localization.

  Keywords: pappiloma virus, limph nodes.

• 115 - Study of circulating influenza virus strains in the south-east  of Romania during the period February 2 - April 4, 2002 - Florica Topârceanu, Mădălina Boldescu, Alina Năstasie [more...]

  „Åžtefan S. Nicolau” Institute of Virology, Bucharest, Romania
  Abstract. At the National Centre of Influenza and Respiratory Virus Disease in the Institute of Virology- Bucharest, systematic researches are performed on the circulation of influenza viruses in the South-East area of Romania. In the present work are set the results obtained by the investigation of the biological samples (nasopharyngeal secretions and blood) taken from 168 patients in the epidemic influenza foci recurred during the period February 2 – April 4, 2002, in Bucharest and in the Tulcea, Constanza and Buzău Districts. The study consisted in the isolation of 20 influenza virus strains, 18 of which were identified as being of the A/Panama/2007/99-like (H3N2) type, the 2 others belonging to the A/New Caledonia/20/99 (H1N1) type, and resulted in the finding of the prevalence of influenza serum antibodies to the A/Panama/2007/99 (H3N2) antigen as compared with the A/New Caledonia/20/99 (H1N1) and B/Yamanashi/166/98 antigens. These results demonstrate the circulation predominence of type A(H3N2) influenza virus strains in the course of the influenza epidemic occurred during the investigated period.

  Keywords: influenza virus isolates, influenza serum antibodies, influenza epidemic.

• 121 - Human seric immunoglobulin characterization by using chemical modification by diferent specific agents - Mirela Hirt¹, I. Baciu², Cecilia Galatiuc¹, Marinela Bostan¹, Lorelei Irina BraÅŸoveanu¹ [more...]

  ¹Center of Immunology – „Åžtefan S. Nicolau” Virology Institute, Bucharest, Romania
  ²Bucharest University, Faculty of Chemistry, Bucharest, Romania
  Abstract. The paper rewievs the known literature data regarding the chemical structure of the major classes of immunoglobulins with a special emphasis on antigen:antibody interactions and immunoglobulin involvement in mediating some important immunological functions, such as the interaction with Fc receptors (FcR) and complement activation. Since changes in imunoglobuline structure observed in some pathological conditions (LES, diabetes) affects their recognition and functional properties and our interest in characterization of specific interaction of cytophilic immunoglobulins with the FcgR, a consistent part of the paper is dealing with possible chemical modifications of the native structure of immunoglobulins. Acylation with acid anhydrides, thiolation, reductive alkylation, reaction with aryl sulfonates, guanidition (reactions for amino groups), and esterification, coupling with nucleophile after activation (reactions for carboxyl groups) offer important informations regarding the structure of binding sites and spatial conformation of modified molecules affecting their involvement in mediating some phisiological functions.

  Keywords: immunoglobulins (Ig); complement C; antigen:antibody interaction (Ac-Ag); Fc receptors (FcR).

• 133 - Mathematical modeling of the drug molecules delivery mechanism using liposomes as carriers - D. Popescu^1,3 and C.N. Zaharia² [more...]

  ¹University of Bucharest, Faculty of Biology, Department of Neurobiology and Biophysics,
  Bucharest, Romania
  ²„Åžtefan S. Nicolau” Institute of Virology, Bucharest, Romania
  ³Institute of Statistical Mathematics and Applied Mathematics, Bucharest, Romania
  Abstract. The transport of drug molecules to the place of their pharmacological action, using liposomes as vehicles, is a way which may be achieved from biotechnological point of view. In this paper we have described a method for the delivery of drug molecules in quantities and according to a timetable both established a priori. Drug quantities and timetable parameters were determined by the physical properties of liposomes and external and internal medium.

  Keywords: liposomes, pores, swelling time, drug delivery.

• 139 - Controlled drug release system based on silicon microreservoirs - A. Albulescu¹, Irina Kleps², Mihaela Miu², Anca Angelescu², Mihaela Albulescu³, R. Iuksel¹, Georgeta Caraene¹, Laura Bud¹, R. Albulescu¹, P. Filip⁴ [more...]

  ¹National Institute for Chemical-Pharmaceutical Research&Development, Bucharest, Romania
  ²Institute of Microtechnology, Bucharest, Romania
  ³National Agency for Dangerous Substances and Preparations, Bucharest, Romania
  ⁴Institute of Organic Chemistry, Bucharest, Romania
  Abstract. Biocompatible silicon is an interesting platform for nanotechnologies with bio-medical applications, such as: controlled drug delivery systems, vaccine administration, tissue engineering, implants, neuron interfaces, biosensors. The controlled drug delivery systems are simple in development and use, can function for long periods, can release different types of medicines in a controllable continuous or pulsatory  way. In our study two types of microreservoirs were produced: one with 1 well and one with 4 wells. The microreservoirs were afterwards tested in order to determine drug release kinetics. Two in vitro testing of drug release kinetics were attempted, using crystal violet as active substance in horse serum as medium (1) and progesterone in  ethyl alcohol (2). Release rate was fairly constant for both models.The microreservoirs in vitro release kinetics is similar to the theoretical model for a controlled drug delivery system for both progesterone and crystal violet.

  Keywords: silicon microreservoirs, drug release, in vitro realease kinetics.