Ensaio imunoenzimático: detecção de anticorpos anti-adenovirus numa população infantil de São Paulo

Com a finalidade de encontrar um ensaio preciso para a detecção de anticorpos anti-adenovírus, o teste ELISA recentemente padronizado foi comparado à imunofluorescência indireta (IFI) e à fixação de complemento (FC). Após testar 58 soros, o ELISA demonstrou maior sensibilidade do que a IFI e a FC, que mostraram sensibilidades relativas de 94% e 63%, respectivamente. A falta de um padrão universal não permitiu alcançar conclusões definitivas quanto à especificidade dos ensaios. Além disso, o ELISA foi utilizado para estabelecer a prevalência de anticorpos anti-adenovírus em 116 crianças entre 1 e 24 meses de idade (média 7.28). Os dados mostraram que os anticorpos maternos desaparecem ao redor dos 5 a 6 meses de idade e que mais de 80% das crianças tinham sido infectadas antes dos 10 meses de idade.In order to define an accurate assay for anti-adenovirus antibody detection, a recently developed ELISA was compared with IFA and CF. On 58 sera, the ELISA was more sensitive than both CF and IFA, which showed relative sensitivities of 63% and 94%, respectively. It was not possible to determine the exact specificity of the tests because of the lack of a gold standard. Furthermore, the ELISA was used to define the prevalence of adenovirus antibodies in 116 infants between 1 and 24 months old (mean 7.28). The data showed that maternal antibodies waned by the age of 5 to 6 months and that more than 80% of the children had been infected by adenoviruses by the age of 10 months

Esclerose múltipla e interação com os herpesvirus

Multiple sclerosis is the most common autoimmune inflammatory demyelinating disease of the central nervous system, and its etiology is believed to have both genetic and environmental components. Several viruses have already been implicated as triggers and there are several studies that implicate members of the Herpesviridae family in the pathogenesis of MS. The most important characteristic of these viruses is that they have periods of latency and exacerbations within their biological sanctuary, the central nervous system. The Epstein-Barr, cytomegalovirus, human herpesvirus 6 and human herpesvirus 7 viruses are the members that are most studied as being possible triggers of multiple sclerosis. According to evidence in the literature, the herpesvirus family is strongly involved in the pathogenesis of this disease, but it is unlikely that they are the only component responsible for its development. There are probably multiple triggers and more studies are necessary to investigate and define these interactions.A esclerose múltipla é a doença inflamatória auto-imune mais comum do sistema nervoso central. Sua etiologia já foi creditada apresentar tanto causas genéticas quanto ambientais. Vários vírus já foram implicados como desencadeadores desta doença e existem inúmeros trabalhos fazendo correlação entre a família Herpesviridae e a patogênese da esclerose múltipla. As características mais importantes dos Herpesviridae são as de apresentarem períodos de latência e exacerbação e terem como seu principal santuário biológico o sistema nervoso central. O vírus Epstein-Barr, o citomegalovírus, o herpesvirus tipo 6 e herpesvirus tipo 7 são os membros mais estudados como desencadeadores da esclerose múltipla. Conforme as evidencias que a literatura apresenta a família Herpesviridae está fortemente envolvida na patogênese da esclerose múltipla, porém é pouco provável que sejam os únicos responsáveis pelo seu início. É provável que esta doença apresente inúmeros desencadeadores e mais estudos são necessários para determinar estas interações

BK virus salivary shedding and viremia in renal transplant recipients

Objectives: This study aimed to verify the presence of polyomavirus BK (BKPyV) in the saliva of kidney transplant recipients and to correlate it with blood viremia. Material and Methods: We have conducted a crosssectional study with a sample involving 126 renal transplant recipients. 126 samples of saliva and 52 samples of blood were collected from these patients. Detection and quantification of BKPyV were performed using a real-time PCR. To compare the presence of BKPyV in blood and saliva, the binomial proportion test was used. To verify associations between salivary shedding BKPyV and post-transplant periods (in months), the Mann-Whitney test was used. Spearman’s correlation was used to correlate the viral load in the saliva with blood of kidney transplant recipients. Results: The mean age of the study group was 51.11±12.45 years old, and 69 participants (54.8%) were female, with a mean post-transplantation time of 4.80±6.04 months. BKPyV was quantified in several samples of saliva and blood, with medians of 1,108 cp/mL and 1,255 cp/mL, respectively. Only 16/52 (30.8%) participants presented BKPyV in blood, and 59/126 (46.8%) excreted the virus in saliva (p=0.004). BKPyV shedding was found in patients at a shorter post-transplantation period (3.86±5.25, p=0.100). A weak correlation was observed between viral quantification in saliva and blood (Spearman’s correlation coefficient=0.193). Conclusion: The results of this study suggested that, although saliva excretes more BKPyV than blood, there is no reliable correlation between salivary shedding and blood viremia, showing two independent compartments of viral replication

HERV-W/MRSV envelope transcripts detection\ud in blood of multiple sclerosis patients after\ud Natalizumab treatment

FAPESP 2010/10619-

Determination of Silver(I) by Differential Pulse Voltammetry Using a Glassy Carbon Electrode Modified with Synthesized N-(2-Aminoethyl)-4,4′-Bipyridine

A new modified glassy carbon electrode (GCE) based on a synthesized N-(2-aminoethyl)-4,4′-bipyridine (ABP) was developed for the determination of Ag(I) by differential pulse voltammetry (DPV). ABP was covalently immobilized on GC electrodes surface using 4-nitrobenzendiazonium (4-NBD) and glutaraldehyde (GA). The Ag(I) ions were preconcentrated by chemical interaction with bipyridine under a negative potential (−0.6 V); then the reduced ions were oxidized by differential pulse voltammetry and a peak was observed at 0.34 V. The calibration curve was linear in the concentration range from 0.05 μM to 1 μM Ag(I) with a detection limit of 0.025 μM and RSD = 3.6%, for 0.4 μM Ag(I). The presence of several common ions in more than 125-fold excess had no effect on the determination of Ag(I). The developed sensor was applied to the determination of Ag(I) in water samples using a standard addition method

Human polyomaviruses JC and BK in the urine\ud of Brazilian children and adolescents vertically infected by HIV

The aim of this study was to characterize the urinary excretion of the BK (BKV) and JC (JCV) human polyomavi\ud -\ud ruses in a cohort of human immunodeficiency virus (HIV)-infected children and adolescents. One hundred and fifty-\ud six patients were enrolled: Group I included 116 HIV-infected children and adolescents [median age = 11.4 years (y);\ud range 1-22 y]; Group II included 40 non-HIV-infected healthy controls (median age = 11.37 y; range 7-16 y). Single\ud urine samples from both groups were screened for the presence of JCV and BKV DNA by polymerase chain reaction\ud at enrolment. The overall rate of JCV and BKV urinary excretion was found to be 24.4% and 40.4%, respectively\ud (n = 156). Group I had urinary excretion of JCV and BKV in 27.6% and 54.3% of subjects, respectively. In contrast,\ud Group II showed positive results for JCV in 17.5% of subjects and for BKV in 12.5% of subjects (p Pearson JCV =\ud 0.20; p Pearson BKV < 0.0001). In Group I, there was no association between JCV/BKV shedding and age, gender\ud or CD4 values. Patients with an HIV viral load < 50 copies/mL had a lower excretion of BKV (p < 0.001) and a trend\ud of lower JCV excretion (p = 0.07). One patient in Group I (1/116, 0.9%) showed clinical and radiological features\ud consistent with progressive multifocal leukoencephalopathy, suggesting that children with HIV/polyomavirus coin\ud -\ud fection should be kept under surveillance.Financial support: FAPESP (07/06687-7

Enzyme linked immunosorbent assay: determination of anti-adenovirus antibodies in an infant population

In order to define an accurate assay for anti-adenovirus antibody detection, a recently developed ELISA was compared with IFA and CF. On 58 sera, the ELISA was more sensitive than both CF and IFA, which showed relative sensitivities of 63% and 94%, respectively. It was not possible to determine the exact specificity of the tests because of the lack of a gold standard. Furthermore, the ELISA was used to define the prevalence of adenovirus antibodies in 116 infants between 1 and 24 months old (mean 7.28). The data showed that maternal antibodies waned by the age of 5 to 6 months and that more than 80% of the children had been infected by adenoviruses by the age of 10 months

Community-acquired pneumonia in Chile: the clinical relevance in the detection of viruses and atypical bacteria

Background Adult community-acquired pneumonia (CAP) is a relevant worldwide cause of morbidity and mortality, however the aetiology often remains uncertain and the therapy is empirical. We applied conventional and molecular diagnostics to identify viruses and atypical bacteria associated with CAP in Chile.\ud \ud Methods We used sputum and blood cultures, IgG/IgM serology and molecular diagnostic techniques (PCR, reverse transcriptase PCR) for detection of classical and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumoniae) and respiratory viruses (adenovirus, respiratory syncytial virus (RSV), human metapneumovirus, influenza virus, parainfluenzavirus, rhinovirus, coronavirus) in adults >18 years old presenting with CAP in Santiago from February 2005 to September 2007. Severity was qualified at admission by Fine's pneumonia severity index.\ud \ud Results Overall detection in 356 enrolled adults were 92 (26%) cases of a single bacterial pathogen, 80 (22%) cases of a single viral pathogen, 60 (17%) cases with mixed bacterial and viral infection and 124 (35%) cases with no identified pathogen. Streptococcus pneumoniae and RSV were the most common bacterial and viral pathogens identified. Infectious agent detection by PCR provided greater sensitivity than conventional techniques. To our surprise, no relationship was observed between clinical severity and sole or coinfections.\ud \ud Conclusions The use of molecular diagnostics expanded the detection of viruses and atypical bacteria in adults with CAP, as unique or coinfections. Clinical severity and outcome were independent of the aetiological agents detected.This work was supported by the Fondo Nacional de Ciencia y Tecnología (FONDECYT) (grant number 1050734); and the Fondo Nacional de Investigación en Salud (FONIS) (grant number SA04 I 2084)