Distribution of rabies virus in infected mice, vaccinated and submitted to P-acnes as immunomodulator

The lethality and distribution of rabies virus were evaluated in swiss mice experimentally infected with street rabies virus, vaccinated and submitted to immunomodulation by P. acnes (formerly Corynebacterium parvum). The animals were sacrificed at different times,when the different tissues were collected and submitted to fluorescent antibody test (FAT) and mouse inoculation test (MIT). The group submitted to vaccination and P. acnes treatment presented a percentage of survival superior to that observed in infected mice only treated with P. acnes. Control infected animals had the lowest survival rates. The distribution of rabies virus in spleen of infected mice, vaccinated and submitted to P. acnes was superior to that verified in infected mice not treated with P. acnes. The increased survival correlated with the distribution of rabies virus in lymphoid tissues, could be interpreted as the consequence of P. acnes activity on macrophages. The results suggest the role of macrophages against rabies virus infection in mice and the importance of vaccination in the post expositive treatment of rabies. (C) 2002 Published by Elsevier B.V. Ltd.

Exposure to rabies virus in a population of free-ranging capuchin monkeys (Cebus apella nigritus) in a fragmented, environmentally protected area in southeastern Brazil

The aim of this study is to assess the frequency of rabies antibodies in free-ranging capuchin monkeys (Cebus apella nigritus) in a fragmented, environmentally protected, rural area of southeastern Brazil. Thirty-six free-ranging monkeys were tested by the rapid fluorescent focus inhibition test for detection of antibodies against rabies virus. Four individuals (11.11 %) had neutralizing antibody titers a parts per thousand yen0.25 IU/mL, demonstrating rabies virus exposure.

Detection of bovine Herpesvirus type 5 in formalin-fixed, paraffin-embedded bovine brain by PCR: a useful adjunct to conventional tissue-based diagnostic test of bovine encephalitis

The aim of this study was to evaluate the application of PCR technique for the detection of BoHV-5 in routinely formalin-fixed, paraffin-embedded brain tissues in 20 naturally infected calves affected by fatal meningoencephalitis. Brains were divided into two halves, one kept fresh for virus isolation and PCR assay, targeting the glycoprotein C gene from BoHV-5 genome. The other half brain, corresponding to posterior cortex region, was submitted to formalin fixation and embedded into paraffin blocks for microscopic evaluation and total DNA isolation. Most of the slides showed severe multifocal non-supurative encephalitis with neuronal degeneration, neurophagia, and no acidophilic intranuclear inclusions could be found in neurons and glial. The 20 fresh samples were confirmed, by virus isolation and PCR assay, as having the BoHV-5 virus and, respective glicoprotein C sequence, while 15 of 20 formalin-fixed, paraffin-embedded samples were considered positive for the same analysis. The results revealed the first description of PCR efficiency, applied to formalin-fixed, paraffin-embedded brain collected from naturally infected calves, improving the detection of BoHV-5 from archival samples in South America. (c) 2007 Published by Elsevier B.V.

Effect of Acid Neutralization and Mechanical Cycling on the Microtensile Bond Strength of Glass-ceramic Inlays

Objectives: To evaluate the hypothesis that a process of hydrofluoric acid precipitate neutralization and fatigue load cycling performed on human premolars restored with ceramic inlays had an influence on microtensile bond strength results (MTBS). Methods: MOD inlay preparations were performed in 40 premolars (with their roots embedded in acrylic resin). Forty ceramic restorations were prepared using glass-ceramic (IPS Empress). The inner surfaces of all the restorations were etched with 10% hydrofluoric acid for 60 seconds, rinsed with water and dried. The specimens were divided into two groups (N=20): 1-without neutralization; 2-with neutralization. All the restorations were silanized and adhesively cemented (self-curing and self-etching luting composite system, Multilink). Ten premolars from each group were submitted to mechanical cycling (1,400,000 cycles, 50N, 37 degrees C). After cycling, the samples were sectioned to produce non-trimmed beam specimens (vestibular dentin-restoration-lingual dentin set), which were submitted to microtensile testing. Results: Bond strength was significantly affected by the surface treatment (p<0.0001) (no neutralization > neutralization) and mechanical cycling (p<0.0001) (control > cycling) (2-way ANOVA and Tukey test, alpha=.05). Conclusion: Hydrofluoric acid precipitate neutralization appears to significantly damage the resin bond to glass-ceramic and should not be recommended. The clinical simulation of the specimens, by using mechanical cycling, is important when evaluating the ceramic-dentin bond.

Efeitos na fotossíntese e área foliar de cultivares de alface inoculadas mecanicamente com patótipos do Lettuce mosaic virus e Lettuce mottle virus

Levantamentos realizados no estado de São Paulo indicaram a ocorrência isolada e em infecções mistas do Lettuce mosaic virus (LMV) e do Lettuce mottle virus (LeMoV) em plantas de alface (Lactuca sativa). O presente trabalho teve como objetivo estudar os efeitos da infecção isolada e mista entre o LMV (patótipos II e IV) e o LeMoV, em cultivares de alface suscetível (White Boston) e tolerante (Elisa - gene mol¹) ao LMV patótipo II. As plantas foram inoculadas via extrato vegetal tamponado com isolados de LMV-II, LMV-IV e LeMoV separadamente e em diferentes combinações, com intervalo de 24 h ou simultaneamente com os dois vírus. As plantas infetadas foram analisadas utilizando-se hospedeiras diferenciais para o LMV e o LeMoV, e no caso do LMV pelo teste sorológico de PTA-ELISA. Nas avaliações de peso fresco e seco, área foliar e teor de clorofila, observou-se que a cultivar White Boston foi a mais afetada por ambos os vírus. As infecções mistas e isoladas na cultivar Elisa causaram efeitos semelhantes, provavelmente devido a presença do gene mo1¹ de tolerância ao LMV-II. O isolado LMV-IV foi considerado o mais agressivo nestas cultivares quando comparado ao LMV-II e o LeMoV.

Using pegylated interferon alfa-2b and ribavirin to treat chronic hepatitis patients infected with hepatitis C virus genotype 1: Are nonresponders and relapsers different populations?

The combination of pegylated interferon (PEG-INF) and ribavirin is currently the best treatment for chronic hepatitis C, providing a sustained virological response (SVR) in 54%-63% of patients. In patients infected with hepatitis C virus (HCV) genotype 1, the SVR rate is 42%-52%. To evaluate the treatment efficacy of this drug combination, we conducted an open, prospective study of 58 consecutive treatment-naive patients infected with HCV genotype 1 and treated at a university hospital, comparing those presenting an SVR (SVRs), nonresponders (NRs), and relapsers (RELs). Among the intent-to-treat patients, an end-of-treatment virological response was achieved in 69 % of the sample as a whole and in 52 % of the SVRs. We found that being an SVR was significantly associated with mild fibrosis (p = 0.04) and with undetectable HCV RNA at weeks 12 and 24 of treatment (p < 0.0001). Comparing the SVR and REL groups, we observed that being older than 40 was significantly associated with being a REL (p = 0.04). Being an NR was found to be associated with severe fibrosis and moderate inflammatory infiltrates (portal or periportal). In the polytomous logistic regression, no independent factors were associated with the REL group when compared with the SVR group. We conclude that RELs and NRs differ in comparison with SVRs. The RELs accounted for 17% of the sample. The HCV RNA test results at weeks 12 and 24 of treatment, although independent predictors of non-response (OR: 4.8 and 8.2, respectively), did not differ between SVRs and RELs.

Detection and quantification of antibodies to Newcastle disease virus in ostrich and rhea sera using a liquid phase blocking enzyme-linked immunosorbent assay

A liquid phase blocking ELISA (LPB-ELISA) was adapted for the detection and quantification of antibodies to Newcastle disease virus. Sera from vaccinated and unvaccinated commercial flocks of ostriches (Struthio camelus) and rheas (Rhea americana) were tested. The purified and nonpurified virus used as the antigen and the capture and detector antibodies were prepared and standardized for this purpose. The hemagglutination-inhibition (HI) test was regarded as the reference method, the cutoff point for the LPB-ELISA was determined by a two-graph receiver operating characteristic analysis. The LPB-ELISA titers regressed significantly (P < 0.0001) on the HI titers with a high correlation coefficient (r = 0.875). The two tests showed good agreement ( = 0.82; P < 0.0001), relative sensitivity (90.91%) and specificity (91.18%), and accuracy (91.02%), suggesting that they are interchangeable.

Productive and reproductive performance in cattle infected with bovine leukosis virus

Economic losses caused by enzootic bovine leukosis (EBL) have been of interest since World War II, when the neoplastic form of EEL increased dramatically in Europe. Olson (1974) and House et al. (1975) ed that animals with lymphosarcoma caused by the bovine leukosis virus (BLV) had reduced milk yields. a less efficient reproductive performance and high veterinary costs and mortality rates, while many carcasses were rejected at slaughter. However, the actual impact of BLV infection in cattle without lymphosarcoma is not; clear. The purpose of the study reported here was to compare some productive and reproductive responses of cattle that were antibody-positive (BLV+) or negative (BLV-) for BLV.Holstein dairy cows in commercial dairy farms were used in this study. Blood samples were collected and subjected to BLV serological examination by the agar gel immunodiffusion test of Miller & van der Maaten (1976). Animals were then grouped as BLV+ or BLV- according to their serological response to the BLV antigen. Productive and reproductive histories were obtained from individual animal records and the following factors were considered: milk production, calving interval and birth rate. For milk production, we had the daily milk yields of 547 animals, and for calving interval the time between two successive parturitions for 444 cows. These values were examined by ANOVA and when this was significant a Student's t test was carried out for each age group. Birth rates, the percentage of animals that calved in 1 gear, were available for 557 animals and were examined with the Z-two proportion test. For all analyses, P < 0.05 was considered significant.

Detection of immunoglobulin G antibodies to Neospora caninum in humans: High seropositivity rates in patients who are infected by human immunodeficiency virus or have neurological disorders

Considering that little is known about the epidemiology of Neospora caninum infection in humans, particularly in populations with high Toxoplasma gondii infection rates, the present study aimed to investigate the presence of antibodies to N. caninum in T. gondii-seropositive and -seronegative individuals. A total of 256 serum samples divided into four groups (61 samples from human immunodeficiency virus [HIV]-positive patients, 50 samples from patients with neurological disorders, 91 samples from newborns, and 54 samples from healthy subjects) were assessed for N. caninum and T. gondii serologies by indirect fluorescent-antibody test, enzyme-linked immunosorbent assay, and immunoblotting (IB). Immunoglobulin G antibodies to N. caninum were predominantly detected in HIV-infected patients (38%) and patients with neurological disorders (18%), while newborns and healthy subjects showed lower seropositivity rates (5% and 6%, respectively). Seropositivity to N. caninum was significantly associated with seropositivity to T. gondii in both HIV-infected patients and patients with neurological disorders. Seroreactivity to N. caninum was confirmed by IB, with positive sera predominantly recognizing the 29-kDa antigen of N. caninum. The results of this study indicate the presence of N. caninum infection or exposure in humans, particularly in HIV-infected patients or patients with neurological disorders, who could have opportunistic and concurrent infections with T. gondii. These findings may bring a new concern for the unstable clinical health of HIV-infected patients and the actual role of N. caninum infection in immunocompromised patients.

Progression of liver fibrosis in blood donors infected with hepatitis C virus

Background/Aims. Chronic hepatitis by HCV is progressive towards cirrhosis, with variable rate. We evaluated the rate of fibrosis progression (RFP), risk factors associated with advanced fibrosis (F3 and F4), and estimated the evolution time to cirrhosis. Methods. We transversely selected 142 blood donors infected only with HCV, with a known route of infection, submitted to liver biopsy at admission. RFP= ratio between stage of fibrosis (METAVIR)/estimated duration of infection in years. Non-parametric tests and logistic regression analysis, with significance level of 5% were used. Results. Median RFP was 0.086 U/year (0.05 - 0.142). Ten patients had F4 and 25 had F3. Median RFP values were significantly different (p=0.001) from one age group at contamination to the others and ALT and AST levels. There were no differences in the expected evolution to cirrhosis between intermediate fibrosers (F2) and the rapid fibrosers (F3 and F4). The independent variables associated with advanced fibrosis were ALT (OR 7.2) and GGT (OR 6.4) and age at inclusion (OR 1.12). Conclusion. This study suggests that RFP is extremely variable, it is exponential with age, and mainly influenced by host characteristics, especially age at contamination and possibly ethnical group. These asymptomatic patients had high percentage of fibrosis F2, F3 and F4.

Heminested reverse-transcriptase polymerase chain reaction (hnRT-PCR) as a tool for rabies virus detection in stored and decomposed samples

Background. The use of methods, both sensitive and specific, for rabies diagnosis are important tools for the control and prophylaxis of the disease. Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) has been used in rabies diagnosis with good results, even in decomposed materials. Additionally, molecular techniques have been used for epidemiological studies and to gain a better knowledge of viral epidemiology. Findings. The aim of this work was to evaluate the RT-PCR and hnRT-PCR for rabies virus detection in original tissues stored at -20°C for different periods considering their use for rabies virus detection in stored and decomposed samples. RT-PCR and hnRT-PCR were evaluated in 151 brain samples from different animal species, thawed and left at room temperature for 72 hours for decomposition. The RT-PCR and hnRT-PCR results were compared with previous results from Direct Fluorescent Antibody Test and Mouse Inoculation Test. From the 50 positive fresh samples, 26 (52%) were positive for RT-PCR and 45 (90%) for hnRT-PCR. From the 48 positive decomposed samples, 17 (34, 3%) were positive for RT-PCR and 36 (75%) for hnRT-PCR. No false-positives results were found in the negatives samples evaluated to the molecular techniques. Conclusion. These results show that the hnRT-PCR was more sensitive than RT-PCR, and both techniques presented lower sensibility in decomposed samples. The hnRT-PCR demonstrated efficacy in rabies virus detection in stored and decomposed materials suggesting it's application for rabies virus retrospective epidemiological studies. © 2008 Arajo et al; licensee BioMed Central Ltd.

Use of reverse transcriptase polymerase chain reaction (RT-PCR) in molecular screening of Newcastle disease virus in poultry and free-living bird populations

The aim of this study was to evaluate a simple molecular method of reverse transcriptase polymerase chain reaction (RT-PCR) to differentiate Newcastle disease virus strains according to their pathogenicity, in order to use it in molecular screening of Newcastle disease virus in poultry and free-living bird populations. Specific primers were developed to differentiate LaSota-LS-(vaccine strain) and Sao Joao do Meriti-SJM-strain (highly pathogenic strain). Chickens and pigeons were experimentally vaccinated/infected for an in vivo study to determine virus shedding in feces. Validation of sensitivity and specificity of the primers (SJM and LS) by experimental models used in the present study and results obtained in the molecular analysis of the primers by BLAST made it possible to generalize results. The development of primers that differentiate the level of pathogenicity of NDV stains is very important, mainly in countries where real-time RT-PCR is still not used as a routine test. These primers were able to determine the presence of the agent and to differentiate it according to its pathogenicity. © 2012 Springer Science+Business Media B.V.

Investigation of the state of virus carrier of newcastle disease in budgerigars (melopsittacus undulatus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Epidemiology of human immunodeficiency virus-visceral leishmaniasis-co-infection

In Brazil, the rates of mother-to-child-transmission (MTCT) of human immunodeficiency virus (HIV) decreased from 20% to 1-2% in some regions. However, the country contains 90% of individuals infected with visceral leishmaniasis (VL) in Latin America, and the west region of São Paulo state faces an alarming expansion of the disease. We describe the epidemiological aspects of the expanding infection of VL and a case report of an HIV-VL-co-infected child from the west region of São Paulo state. The patient was an AIDS-C3 with low levels of CD4, high viral load, severe diarrhea, oral and perineal candidiasis, severe thrombocytopenia, and protein-caloric malnourishment. She evolved with sepsis, renal and cardiac failure. An rK rapid diagnosis test, indirect fluorescent antibody test (IFAT), and bone marrow aspirate were performed for VL. Her symptoms improved significantly after liposomal amphotericin B administration. From the 45 municipalities that compose the Regional Health Department of Presidente Prudente, Lutzomyia longipalpis vectors were found in 58% of them. VL infected dogs were found in 33% of those municipalities, infected dogs and humans were found in 29%, 20% are starting and 33% of the municipalities are preparing VL investigation. It is likely, in this patient, that VL advanced the clinical progression of the HIV disease and the development of AIDS severity. Supported by favorable conditions, the region becomes a new frontier of VL in Brazil. © 2013.

Triplet entropy analysis of hemagglutinin and neuraminidase sequences measures influenza virus phylodynamics

The influenza virus has been a challenge to science due to its ability to withstand new environmental conditions. Taking into account the development of virus sequence databases, computational approaches can be helpful to understand virus behavior over time. Furthermore, they can suggest new directions to deal with influenza. This work presents triplet entropy analysis as a potential phylodynamic tool to quantify nucleotide organization of viral sequences. The application of this measure to segments of hemagglutinin (HA) and neuraminidase (NA) of H1N1 and H3N2 virus subtypes has shown some variability effects along timeline, inferring about virus evolution. Sequences were divided by year and compared for virus subtype (H1N1 and H3N2). The nonparametric Mann-Whitney test was used for comparison between groups. Results show that differentiation in entropy precedes differentiation in GC content for both groups. Considering the HA fragment, both triplet entropy as well as GC concentration show intersection in 2009, year of the recent pandemic. Some conclusions about possible flu evolutionary lines were drawn. © 2013 Elsevier B.V.