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Background: The conditions caused by BK polyomavirus (BKV) reactivation are gaining important clinical significance in kidney transplant centers worldwide.Methods: For the first time in Bulgaria, we tried to perform investigations on BKV reactivation on a selected group of kidney transplant patients. By the use of surrogate diagnostic markers urine cytology and PCR on urine/plasma--we tried to evaluate their BKV reactivation and also in related recipient pairs. Sequence analysis was also applied in order to relate the viral genotype to the unfavorable prognosis, where observed.Results: The high incidence of viruria among allograft recipients (n=42/50, 84%) was linked occasionally to BKV disease, only in n=2/50 (4%) patients, presumptive BK-associated nephropathy (BKAN). BKAN genotypes analyzed by sequencing belonged to one genotype, which is frequently observed. BKV reactivation prior to transplantation in related transplant pairs was 25% (n=2/8) in the recipients who had viruria and viremia at the same time. [ABSTRACT FROM AUTHOR]

Introduction/Purpose: Reverse transcriptase-polymerase chain reaction (RT-PCR) for detection, typing, and subtyping of the hemagglutinin and neuraminidase genes of influenza type A (H3N2 and H1N1) viruses in patients' specimens has been developed and applied for the purpose of influenza virological surveillance in the 2003/2004 and 2004/2005 winter seasons. The technique was performed prior to the viral isolation, in order to determine the influenza outbreaks' etiological agent. Methods: During the 2003/2004 season, RT-PCR was performed following an initial screening of 50 patients' samples by 3 other methods. In the 2004/2005 season, the method was used for direct identification of 77 clinical samples. Results/Discussion: All the samples tested were taken during the peak of influenza outbreaks. The report presented is the first one for the country to demonstrate an RT-PCR effective application in influenza virus detection in clinical samples from epidemic outbreaks. [ABSTRACT FROM AUTHOR]

Aim: Prevention and treatment of upper respiratory tract infections are given the highest priority because of the tremendous health and economic impact of these diseases. Development of novel effective and safe options for treatment can contribute considerably to decrease the burden of disease., Materials and Methods: We designed a multicenter, randomized, double-blind, placebo-controlled study in ambulatory-treated adult patients with a clinical diagnosis of acute upper respiratory tract viral infection. The patients (18-60 years old) were randomized into two groups and followed-up for 5 days. Group 1 received the standard symptomatic therapy + Aviron Rapid®, and Group 2 received the standard symptomatic therapy + placebo. The primary endpoint of the study was defined as the duration of disease measured by the percentages of disease-free patients for every 12-hour period of the study., Results: Treating clinically relevant patients with the natural product Aviron Rapid® for 5 days decreases the duration of disease, the intake of antipyretics and the severity of symptoms. Significant difference between the tested groups for most of studied parameters was found as soon as 12 or 24 hours after initiation of administration in favour of active arm and was the most prominent on days 3 and 4. Significant decrease in the total score of symptoms severity was achieved on day 4 and extended to the end of study. There were no dif-ferences in the adverse events between the groups and the tested product demonstrated excellent safety profile., Conclusions: This study is a clinical confirmation of well documented antiviral activity of the product targeting multiple points in viral replication and covering broad spectrum viral pathogens., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Glial brain tumours with their poor prognosis, limited treatment modalities and unclear detailed pathophysiology represent a significant health concern. The purpose of the current study was to investigate and describe the possible role of the human polyomavirus JC as an underlying cancerogenic or co-cancerogenic factor in the complex processes of glial tumour induction and development. Samples from 101 patients with glial tumours were obtained during neurosurgical tumour resection. Small tissue pieces were taken from several areas of the histologically verified solid tumour core. Biopsies were used for DNA extraction and subsequent amplification reactions of sequences from the JC viral genome. Real-time polymerase chain reaction was used for detection and quantification of its non-coding control region (NCCR) and gene encoding the regulatory protein Large T antigen (LT). An average of 37.6% of all patients was found to be LT positive, whereas only 6.9% tested positive for NCCR. The analysis of the results demonstrated significant variance between the determined LT prevalence and the rate for NCCR, with a low starting copy number in all positive samples and threshold cycles in the range of 36 to 42 representing viral load in the range from 10 to 1000 copies/μl. The results most probably indicate incomplete JC viral replication. Under such conditions, mutations in the host cell genome may be accumulated due to interference of the virus with the host cell machinery, and eventually malignant transformation may occur.

A total of 111 fresh brain biopsies from patients with primary brain tumors were examined for JC polyomavirus sequences from the Large T antigen encoding region (LT) and the viral non-coding control region (NCCR). SYBR Green and TaqMan real-time polymerase chain reaction assays were used. In the glioblastoma group of 39 patients 48.7% were positive for LT sequences. Among the astrocytoma group (19 patients) and the oligodendroglioma group (12 patients) 31.6% and 33.3% were also positive. The prevalence of LT genomic sequences among the other groups was as follows: in 2 out of 3 oligoastrocytomas; in 3 out 5 gangliogliomas; in 2 out of 5 meduloblastomas; in 1 out 3 pineocytomas; and in none of the tested 5 ependimomas. All positive samples had a late threshold cycle that varied from 36 to 49, indicative of very low starting viral number. Only 21 of all the 111 samples were positive for NCCR. Low copy number in range of 10-1,000 was present. Notably, only 8 of all NCCR positive specimens were also LT positive. It might be suggested that the disproportion between the results for LT and NCCR is either due to clonally integrated LT fragments, with loss of genetic material, or changes in the NCCR. The latter would alter the productive course of the infection and may establish a premise for continuous interaction of viral regulatory proteins with cell molecules that are responsible for the control of the cell cycle. This may lead subsequently to malignant transformation., (Copyright © 2011 Wiley-Liss, Inc.)

Polyomavirus hominis 1 (BK virus, BKV) is an important pathogen in the field of transplantation medicine. BKV reactivation among renal-transplant recipients could cause BK associated nephropathy, which has unfavorable prognosis and is a cause for graft rejection. It is not clear why only few transplanted patients develop BK associated nephropathy while most exhibit asymptomatic viruria. One of the possible reasons lies in the mutations of the VP1 gene, encoding the main structural protein, bearing important determinants for the recognition of specific cellular receptors. The change of amino acid sequence could result in altered pathogenicity of BKV. The amplified sequences of BK in this research were from urines of patients with various clinical conditions along with healthy individuals. Nevertheless the sequence analysis which was undertaken did not show correlation between the viral genotype and the clinical condition. It was demonstrated that the most common BKV genotype in Bulgaria is genotype I and that the strains common in Bulgaria (genotypes I and IV) have typical European origin. Most of the sequenced BKV DNA samples (8/10) were correlated with the highest degree of similarity (81%) to the subcluster Ib. A specific place among the samples is taken by Pr-9, amplified from the urine of a pregnant woman that has a different evolutionary origins and might establish the beginning of a new distinct BKV strain., ((c) 2009 Wiley-Liss, Inc.)

Host and/or viral factors involved in human polyomavirus (HPoV) infection in persons living with HIV remain unknown. A hypothesis is outlined suggesting the importance of the co-receptors CCR5, CCR2, and CXCR4 not only for HIV, but also for HPoV. Functionally capable receptors coded by wild-type (wt) genotypes could facilitate internalization of HPoV in the cell resulting in brain and/or kidney infection/s in HIV infected individuals. Forty-nine Bulgarians with HIV, all treated by HAART, without neurological and/or kidney disorders, were tested for JCV and BKV and genotyped for CCR5 (CCR5del32), CCR2 (CCR2-64I), and CXCR4 (SDF1-3'A). In 27/49 (55.1%) individuals a co-infection with HPoV was identified-BKV in 12/49 (24.5%), JCV-in another 12/49 (24.5%), and both viruses-in 3/49 (6.1%). A high frequency of wt CCR5 was found in patients with HPoV (91.7% for BKV and JCV and in 100% with both viruses). V/V of CCR2 was presented in 75% for BKV and JCV and in 66.7% for BKV plus JCV. SDF1-3'G/G predominated in JCV infected patients (75%), while G/A and A/A genotypes were more frequent in patients with BKV (41.7%). Also, 21/22 (95.4%) persons without HPoV infection were heterozygous for SDF1 and CCR2. The number of individuals bearing wt of all co-receptors in the group of persons not infected with HPoV was lower (P = 0.03) than that with polymorphism/s in one or two genes (SDF1 and CCR2) in the same group. The results suggest a probable role of co-receptors used by HIV to facilitate infection with HPoV., ((c) 2009 Wiley-Liss, Inc.)

Background: Pregnancy is associated with down-regulation of immune responses of the mother. This might lead to reactivation and vertical transmission of latent viral infections such as BK virus (BKV)., Objectives: To determine the presence of BKV in the urine of pregnant women and in cord blood at delivery., Study Design: We examined urines from 52 pregnant women and 51 cord blood samples for BKV by real-time SYBR green PCR., Results: BKV DNA was found in the urine of 18 (34.6%) pregnant women. No BKV DNA was detected by SYBR green PCR in the cord blood specimens., Conclusions: BKV reactivation is common during pregnancy but this is not associated with BKV in cord blood.

Objective: Recurrent respiratory papillomatosis (RRP) is the most common benign neoplasm affecting the larynx and upper respiratory tract in children. Human papillomavirus (HPV) has been implicated as the cause of RRP, most commonly types 6 and 11. The present study was undertaken to evaluate the occurrence of HPV types in a group of patients with juvenile-onset RRP (JORRP)., Methods: The study group consists of 23 patients with JORRP. The clinical records of the patients were reviewed, and JORRP was classified as non-aggressive or aggressive. The laryngeal biopsies were taken and investigated for HPV DNA presence using real-time polymerase chain reaction (PCR) with a set of consensus primers (MY09/11). Viral typing was subsequently performed by real-time PCR with type-specific primers for HPV types 6, 11, 16, 18, 31, and 33., Results: HPV presence was detected in all samples with amplifiable DNA. HPV-11 was revealed in 61.9% of the patients and HPV-6 in 23.8%. Double positivity for HPV types 6 and 11 was identified in 14.3%. Our findings suggest that RRP runs a more aggressive clinical course when HPV-11 infection is present (p=0.0265)., Conclusions: Our results suggest a high frequency of HPV infection in the upper respiratory tract of the studied patients. We believe that the routine application of molecular techniques such as PCR for detection and analysis of HPVs in patients with RRP has diagnostic and prognostic significance.

Serial virus specimens rescued from rabbits, experimentally infected with bovine immunodeficiency (BIV) strain R29, were monitored for changes in quasispecies population, using the single-strand conformation polymorphism (SSCP) analysis. The generation of characteristic SSCP patterns enables the rapid differentiation of BIV variants derived from the conserved part on the env region of the BIV genome, reducing the need for expensive and time-consuming direct sequencing analyses. Our results showed genetic polymorphism among a number of sampled BIV population in experimentally infected rabbits. At least three SSCP patterns (BIV quasispecies) were detected. The SSCP analysis allows for an easy, sensitive, and rapid screening of genetic variants of the virus and the assessment of variation at a number of tissue target sites. These variations may relate to cell-type targets and/or disease progression, and could be significant to our understanding of lentiviral pathogenesis.

To assess the value of bovine immunodeficiency virus (BIV) infection as a model for human immunodeficiency virus (HIV) infection in man, we studied the impairment of certain immunologic functions in New Zealand white rabbits experimentally infected with an uncloned virulent isolate of the virus, BIV R29. Serum samples were tested by Western blot for the presence and persistence of antibody production. The T- and B-lymphocyte function was studied by evaluation of the blastogenic responsiveness to concanavalin A (Con A) and to dextran sulfate (DxS). All infected rabbits seroconverted to BIV antigens within 2 to 4 weeks postinfection (p.i.) The BIV was isolated from the peripheral blood lymphocytes (PBLs) of 13 of 17 rabbits (77%) early in the infection and also from 5 of 17 hyperplastic mesenteric lymph nodes (29%) and 10 of 17 spleens (59%) during the chronic stage of infection. Seven of 17 BIV-infected rabbits (41%) developed marked immunodepression 2 to 5 months p.i., and later, 5 exhibited a rapidly progressive disease with anorexia, weight loss, neurologic impairment, splenomegaly, and mesenteric lymphadenopathy. These data underline the value of the BIV model for studying HIV pathogenesis in vivo and the development of interventional strategies for AIDS.

The mode of action of the phorbol 12,13-dibutyrate (PDBu) and phorbol 12-myristate 13-acetate (PMA) on the human immunodeficiency virus 1 (HIV-1) replication in human lymphocytes and monocytes was studied. PDBu and PMA appear to have similar effects on the regulation of HIV-1 replication in acutely infected cells. Here we show a significantly increased replication of HIV-1 induced by PDBu and PMA in Molt-4 and Jurkat cells, but a reduced replication in THP-1 and U-937 cells. Moreover, quantitatively different activity of the two derivatives in relation to HIV-1 replication was observed. PDBu proved to be a stronger stimulator or suppressor of HIV-1 replication as compared to PMA. Although the precise mechanism of the activation of HIV-1 replication by phorbol ester derivatives is not clear, it can be assumed that the hydrophilycity of PDBu may cause its stronger effect.

To investigate the effect of bovine immunodeficiency virus (BIV) infection on the rabbit immune system, we studied the proliferative responses of peripheral blood lymphocytes (PBLs) of rabbits experimentally inoculated with BIV. All BIV127-inoculated rabbits seroconverted after 6 weeks and remained seropositive over a prolonged period of time. Assays for specific lymphocyte reactivity to concanavalin A (Con A) were performed monthly for over 1 year. One-hundred percent of infected rabbits developed abnormally low T cell responses, as measured by Con A stimulation. By 3 months postinoculation, the PBL response to Con A was diminished and remained depressed for 6 months. All animals were clinically asymptomatic within 14 months of BIV inoculation. By 15 and 16 months postinoculation, two of three infected rabbits exhibited recurrent lowering of the T cell responsiveness including a decrease in absolute PBL counts. One of these animals died unexpectedly. Our results further confirmed that a functional impairment of lymphocytes was induced early in the course of BIV infection, prior to clinical disease. These findings suggested that BIV infection may mimic asymptomatic infection of human immunodeficiency virus (HIV) and provided further evidence of the importance of BIV-induced disease in rabbits as a relevant model for the study of AIDS.

More than 100 plant extracts from the Amazonian rain forest of Venezuela were evaluated for their cytotoxicity and inhibitory activity against the human immunodeficiency virus type-1 (HIV-1). Aqueous extracts from Fomitella supina (S # 0389-4), Phellinus rhabarbarinus (S # 0389-7), Trichaptum perrottetti (S # 0389-8) and Trametes cubensis (S # 0389-13), Polyporaceae exhibited strong anti-HIV-1 activity, without toxicity for Molt-4 lymphocytic cells. Our results demonstrated, that the compound(s) acted by mechanism of direct virion inactivation and by inhibition of syncytium formation in an in vitro culture system. These results support the suggestion that the test extracts specifically act at the level of CD4-gp120 binding. The active components of these extracts is at present unknown, but anti-AIDS agents, such as those found in this study, individually or in combination, may be of therapeutic relevance.