Inactivation Kinetics and Replication Cycle Inhibition of Coxsackievirus B5 by Free Chlorine.

The kinetics of coxsackievirus serotype B5 (CVB5) inactivation with free chlorine is characterized over a range of pH and temperature relevant to drinking water treatment with the primary goal of selecting experimental conditions used for assessing inactivation mechanisms. The inactivation kinetics identified in our study is similar to or slower than experimental data reported in the literature and thus provides a conservative representation of the kinetics of CVB5 inactivation for free chlorine that could be useful in developing future regulations for waterborne viral pathogens including adequate disinfection treatment for CVB5. Untreated and free chlorine-treated viruses, and host cells synchronized-infected with these viruses, are analyzed by a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method with the goal of quantitatively investigating the effect of free chlorine exposure on viral genome integrity, attachment to host cell, and viral genome replication. The inactivation kinetics observed results from a combination of hindering virus attachment to the host cell, inhibition of one or more subsequent steps of the replication cycle, and possibly genome damage.

Obesidade na infância e adolescência / Obesity in childhood and adolescence

A obesidade é uma doença crônica e multifatorial com sérias repercussões na saúde. O excesso de peso na infância aumenta o risco de obesidade na adolescência e na vida adulta. A obesidade é uma das principais causas de hipertensão arterial em crianças e adolescentes. No sexo feminino, os problemas ginecológicos relacionados com a obesidade incluem as desordens menstruais e a diminuição da fertilidade na adolescência e na vida adulta. O controle dessa patologia evita a sua evolução para formas crônicas e graves, que acarretaria novos transtornos e consequências para essas jovens. A mudança de hábitos alimentares e a realização de atividade física são a principal linha de tratamento. O tratamento medicamentoso é reservado para portadoras de obesidade grave que apresentam comorbidades associadas e que não respondem às mudanças do estilo de vida. (AU)

Obesity is a chronic and multifactorial disease with serious repercussions on health. Overweight in childhood increases the risk of obesity in adolescence and adulthood. Obesity is one of the main causes of high blood pressure in children and adolescents, among others. In women, gynecological problems related to obesity include menstrual disorders and decreased fertility in adolescence and adulthood. The control of this pathology prevents its evolution to chronic and severe forms that would cause new disorders and consequences for these young women. The main line of treatment is to change eating habits and encourage physical activity. Drug treatment is reserved for patients with severe obesity, who have associated comorbidities and who do not respond to changes in lifestyle.(AU)

Adenovirus Replication Cycle Disruption from Exposure to Polychromatic Ultraviolet Irradiation.

Polychromatic ultraviolet (UV) light with bandwidth of 20 nm and peak emission centered at 224, 254, or 280 nm (UV224, UV254, and UV280, respectively) were used to inactivate human adenovirus type 2 (HAdV-2). Quantitative polymerase chain reaction (qPCR) and reverse transcriptase qPCR assays were used to elucidate the step in the HAdV-2 replication cycle that was disrupted after UV exposure. UV treatment at any of the wavelengths analyzed did not inhibit association of HAdV-2 to the host cells even after exposure to a fluence (UV dose) that would produce a virus inactivation efficiency, measured by plaque assay, greater than 99.99%. In contrast, UV irradiation at all three peak emissions disrupted early E1A gene transcription and viral DNA replication, but different mechanisms appeared to be dominating such disruptions. UV224 seemed to have little effect on the integrity of the viral genome but produced a structural transformation of the viral capsid that may inhibit the delivery of viral genome into the host cell nucleus. On the other hand, UV254 and UV280 did not affect the integrity of the viral capsid, but the mutations they produced on the viral genome might cause the inhibition of the early gene transcription and DNA replication after the viral genome successfully translocated into the host cell nucleus.

Respiratory and neurological disease in rabbits experimentally infected with equid herpesvirus 1.

Equid herpesvirus type 1 (EHV-1) is an important pathogen of horses worldwide, associated with respiratory, reproductive and/or neurological disease. A mouse model for EHV-1 infection has been established but fails to reproduce some important aspects of the viral pathogenesis. Then, we investigated the susceptibility of rabbits to EHV-1 aiming at proposing this species as an alternative model for EHV-1 infection. Weanling rabbits inoculated intranasal with EHV-1 Kentucky D (10(7) TCID50/animal) shed virus in nasal secretions up to day 8-10 post-inoculation (pi), presented viremia up to day 14 pi and seroconverted to EHV-1 (virus neutralizing titers 4 to 64). Most rabbits (75%) developed respiratory disease, characterized by serous to hemorrhagic nasal discharge and mild to severe dyspnea. Some animals (20%) presented neurological signs as circling, bruxism and opisthotonus. Six animals died during acute disease (days 3-6); infectious virus and/or viral DNA were detected in the lungs, trigeminal ganglia (TG), olfactory bulbs (OBs) and cerebral cortex/brain (CC). Histological examination showed necrohemorrhagic, multifocal to coalescent bronchointerstitial pneumonia and diffuse alveolar edema. In two rabbits euthanized at day 50 pi, latent EHV-1 DNA was detected in the OBs. Dexamethasone administration at day 50 pi resulted in virus reactivation, demonstrated by virus shedding, viremia, clinical signs, and increase in VN titers and/or by detection of virus DNA in lungs, OBs, TGs and/or CC. These results demonstrate that rabbits are susceptible to EHV-1 infection and develop respiratory and neurological signs upon experimental inoculation. Thus, rabbits may be used to study selected aspects of EHV-1 biology and pathogenesis, extending and complementing the mouse model.