Advances in the development of antiviral strategies against parvovirus B19

Parvovirus B19 (B19V) is a human pathogenic virus, responsible for an ample range of clinical manifestations. Infections are usually mild, self-limiting, and controlled by the development of a specific immune response, but in many cases clinical situations can be more complex and require therapy. Presently available treatments are only supportive, symptomatic, or unspecific, such as administration of intravenous immunoglobulins, and often of limited efficacy. The development of antiviral strategies against B19V should be considered of highest relevance for increasing the available options for more specific and effective therapeutic treatments. This field of research has been explored in recent years, registering some achievements as well as interesting future perspectives. In addition to immunoglobulins, some compounds have been shown to possess inhibitory activity against B19V. Hydroxyurea is an antiproliferative drug used in the treatment of sickle-cell disease that also possesses inhibitory activity against B19V. The nucleotide analogues Cidofovir and its lipid conjugate Brincidofovir are broad-range antivirals mostly active against dsDNA viruses, which showed an antiviral activity also against B19V. Newly synthesized coumarin derivatives offer possibilities for the development of molecules with antiviral activity. Identification of some flavonoid molecules, with direct inhibitory activity against the viral non-structural (NS) protein, indicates a possible line of development for direct antiviral agents. Continuing research in the field, leading to better knowledge of the viral lifecycle and a precise understanding of virus\u2013cell interactions, will offer novel opportunities for developing more efficient, targeted antiviral agents, which can be translated into available therapeutic options

Pre-Existing Intrarenal Parvovirus B19 Infection May Relate to Antibody-Mediated Rejection in Pediatric Kidney Transplant Patients

Viral infections can lead to transplant dysfunction, and their possible role in rejection is described. In total, 218 protocol biopsies performed in 106 children at 6, 12 and 24 months after transplantation were analyzed according to Banff ’15. RT-PCR for cytomegalovirus, Epstein-Barr virus, BK virus and Parvovirus B19 was performed on blood and bioptic samples at the time of transplant and each protocol biopsy. The prevalence of intrarenal viral infection increases between 6 and 12 months after transplantation (24% vs. 44%, p = 0.007). Intrarenal Parvovirus B19 infection is also associated with antibody-mediated rejection (ABMR) (50% ABMR vs. 19% T-cell-mediated rejection, p = 0.04). Moreover, Parvovirus infection is higher at 12 months of follow-up and it decreases at 48 months (40.4% vs. 14%, p = 0.02), while in 24% of grafts, Parvovirus is already detectable at the moment of transplantation. Intrarenal Parvovirus B19 infection seems to be related to ABMR in pediatric kidney recipients. The graft itself may be the way of transmission for Parvovirus, so performance of a PCR test for Parvovirus B19 should be considered to identify high-risk patients. Intrarenal Parvovirus infection presents mainly during the first-year post-transplantation; thus, we recommend an active surveillance of donor-specific antibodies (DSA) in patients with intrarenal Parvovirus B19 infection during this period. Indeed, it should be considered a treatment with intravenous immunoglobulins in patients with intrarenal Parvovirus B19 infection and DSA positivity, even in the absence of ABMR criteria for kidney biopsy

Co-localization of two different viral genomes in the same sample by double-chemiluminescence in situ hybridization

A double-chemiluminescence in situ hybridization has been developed that combines the advantages of chemiluminescence with the detection of two different viral DNAs, i.e., herpes simplex virus (HSV..

Development of C-TILDA: A modified TILDA method for reservoir quantification in long term treated patients infected with subtype C HIV-1

A better characterization of the HIV reservoir is pivotal for the development of effective eradication strategies. Accurate quantification of the latent reservoir remains challenging. Starting from a regular blood draw, the Tat/Rev induced limiting dilution assay (TILDA) combines serial dilution of CD4+ T cells with a PCR-based detection of HIV-1 spliced mRNA produced upon cell stimulation. Here we adapted the original protocol for HIV-1 subtype B to detect tat/rev mRNAs transcribed from reactivated latently infected cells in long term suppressed patients infected with HIV-1 subtype C. Given the heterogeneity of global HIV epidemiology, it is pivotal to develop assays with optimal performances also in patients infected with non-B subtypes. We observed that, in these patients infected with subtype C virus, the HIV reservoir quantified by TILDA correlates with both the time of virological suppression and CD4/CD8 ratio

Parvovirus B19 DNA CpG Dinucleotide Methylation and Epigenetic Regulation of Viral Expression

CpG DNA methylation is one of the main epigenetic modifications playing a role in the control of gene expression. For DNA viruses whose genome has the ability to integrate in the host genome or to maintain as a latent episome, a correlation has been found between the extent of DNA methylation and viral quiescence. No information is available for Parvovirus B19, a human pathogenic virus, which is capable of both lytic and persistent infections. Within Parvovirus B19 genome, the inverted terminal regions display all the characteristic signatures of a genomic CpG island; therefore we hypothesised a role of CpG dinucleotide methylation in the regulation of viral genome expression

Brazilian guidelines for diagnosis, treatment and follow-up of primary cutaneous melanoma - part II

The last Brazilian guidelines on melanoma were published in 2002. Development in diagnosis and treatment made updating necessary. The coordinators elaborated ten clinical questions, based on PICO system. A Medline search, according to specific MeSH terms for each of the 10 questions was performed and articles selected were classified from A to D according to level of scientific evidence. Based on the results, recommendations were defined and classified according to scientific strength. The present Guidelines were divided in two parts for editorial and publication reasons. In this second part, the following clinical questions were answered: 1) which patients with primary cutaneous melanoma benefit from sentinel lymph node biopsy? 2) Follow-up with body mapping is indicated for which patients? 3) Is preventive excision of acral nevi beneficious to patients? 4) Is preventive excision of giant congenital nevi beneficious to patients? 5) How should stages 0 and I primary cutaneous melanoma patients be followed

Evaluation of clinical, laboratory and morphologic prognostic factors in colon cancer

<p>Abstract</p> <p>Background</p> <p>The long-term prognosis of patients with colon cancer is dependent on many factors. To investigate the influence of a series of clinical, laboratory and morphological variables on prognosis of colon carcinoma we conducted a retrospective analysis of our data.</p> <p>Methods</p> <p>Ninety-two patients with colon cancer, who underwent surgical resection between January 1999 and December 2001, were analyzed. On survival analysis, demographics, clinical, laboratory and pathomorphological parameters were tested for their potential prognostic value. Furthermore, univariate and multivariate analysis of the above mentioned data were performed considering the depth of tumour invasion into the bowel wall as independent variable.</p> <p>Results</p> <p>On survival analysis we found that depth of tumour invasion (P < 0.001; F-ratio 2.11), type of operation (P < 0.001; F-ratio 3.51) and CT scanning (P < 0.001; F-ratio 5.21) were predictors of survival. Considering the degree of mural invasion as independent variable, on univariate analysis, we observed that mucorrhea, anismus, hematocrit, WBC count, fibrinogen value and CT scanning were significantly related to the degree of mural invasion of the cancer. On the multivariate analysis, fibrinogen value was the most statistically significant variable (P < 0.001) with the highest F-ratio (F-ratio 5.86). Finally, in the present study, the tumour site was significantly related neither to the survival nor to the mural invasion of the tumour.</p> <p>Conclusion</p> <p>The various clinical, laboratory and patho-morphological parameters showed different prognostic value for colon carcinoma. In the future, preoperative prognostic markers will probably gain relevance in order to make a proper choice between surgery, chemotherapy and radiotherapy. Nevertheless, current data do not provide sufficient evidence for preoperative stratification of high and low risk patients. Further assessments in prospective large studies are warranted.</p

Conformations and internal rotation properties of molecules containing one geminal diphenyl group : diphenylethylene, diphenylketimine, benzophenone, diphenylether and diphenylmethane

The internal rotation potential-energy surfaces for a group of Ph2X type molecules (X = CCH2, CNH, CO, O, CH2) are investigated using an improved INDO-type method (C-INDO) particularly suitable for conformational studies of conjugated compounds. The quantum chemical results, presented as contour energy diagrams, are discussed in detail with regard to both the equilibrium conformations and the features determining internal rotation dynamics. Except for Ph2CH2, which is found to have a gable equilibrium form, all the other Ph2X compounds appear to prefer helical conformations. The height of internal rotation barriers and the size of the low energy regions around the minima indicate that Ph2CH2 and pH2O molecules are extremely flexible, while Ph2CCH2, Ph2CNH and Ph2CO are, comparatively speaking, rather rigid systems. On this basis a scale of conjugating ability is suggested for the series of molecules studied. In addition to the theoretical study, a Raman and infrared investigation of the conformation of all the molecules in question is also reported in order to allow a consistent comparison between theory and experiment, at least as regards the shape of the equilibrium conformations. It is shown that the experimental behaviour of the Ph2X molecules in condensed (solid and liquid) phase (as deduced from vibrational spectroscopy and other sources) can always be reconciled with the C-INDO description for the isolated molecule

A flow-FISH assay for the quantitative analysis of parvovirus B19 infected cells

Human parvovirus B19 (B19V) replication is a process highly dependent on the cellular environment, therefore methodologies allowing for analysis at single cell level could represent effective tools to understand cell-to cell differences in the replication process and to investigate cell-virus interactions. Fluorescence in situ hybridization (FISH) can be combined with flow cytometry (flow-FISH) to enable the detection of target nucleic acid sequences in thousands of individual cells in a short amount of time. In the present study, a flow-FISH assay based on the use of a digoxigenin-labeled genomic probe has been developed to discriminate B19V infected cells following in vitro infection of UT7/EpoS1 cell line and EPCs (erythroid progenitor cells) generated from peripheral blood mononuclear cells. In B19V infected UT7/EpoS1 and EPCs, viral nucleic acids were detected by the flow-FISH assay starting from 24hpi up to 48hpi. The method, used together with quantitative PCR techniques, can be very useful to describe the kinetics of B19V infection within a heterogeneous cell population