Development of Mathematical Models for the Analysis of Hepatitis Delta Virus Viral Dynamics

BACKGROUND: Mathematical models have shown to be extremely helpful in understanding the dynamics of different virus diseases, including hepatitis B. Hepatitis D virus (HDV) is a satellite virus of the hepatitis B virus (HBV). In the liver, production of new HDV virions depends on the presence of HBV. There are two ways in which HDV can occur in an individual: co-infection and super-infection. Co-infection occurs when an individual is simultaneously infected by HBV and HDV, while super-infection occurs in persons with an existing chronic HBV infection. METHODOLOGY/PRINCIPAL FINDINGS: In this work a mathematical model based on differential equations is proposed for the viral dynamics of the hepatitis D virus (HDV) across different scenarios. This model takes into consideration the knowledge of the biology of the virus and its interaction with the host. In this work we will present the results of a simulation study where two scenarios were considered, co-infection and super-infection, together with different antiviral therapies. Although, in general the predicted course of HDV infection is similar to that observed for HBV, we observe a faster increase in the number of HBV infected cells and viral load. In most tested scenarios, the number of HDV infected cells and viral load values remain below corresponding predicted values for HBV. CONCLUSIONS/SIGNIFICANCE: The simulation study shows that, under the most commonly used and generally accepted therapy approaches for HDV infection, such as lamivudine (LMV) or ribavirine, peggylated alpha-interferon (IFN) or a combination of both, LMV monotherapy and combination therapy of LMV and IFN were predicted to more effectively reduce the HBV and HDV viral loads in the case of super-infection scenarios when compared with the co-infection. In contrast, IFN monotherapy was found to reduce the HDV viral load more efficiently in the case of super-infection while the effect on the HBV viral load was more pronounced during co-infection. The results suggest that there is a need for development of high efficacy therapeutic approaches towards the specific inhibition of HDV replication. These approaches may additionally be directed to the reduction of the half-life of infected cells and life-span of newly produced circulating virions

A cross-sectional study on health and physical functioning in relation to coping strategies among community-dwelling, ethnically diverse older women

<p>Abstract</p> <p>Background</p> <p>Although empirical evidence is available on the coping-health link in older age, research on this topic is needed with non-clinical samples of ethnically diverse older women. To contribute to filling such a research gap, we tested whether these women's general health and functional limitations were associated with specific coping strategies (selected for their particular relevance to health issues) and with known health-related demographics, i.e., age, ethnicity, income, and married status.</p> <p>Methods</p> <p>In this cross-sectional study, respondents were recruited at community facilities including stores and senior centers. The sample consisted of 180 community-dwelling women (age 52-98) screened for dementia; 64% of them reported having an ethnic minority status. The assessment battery contained the Mini-Cog, a demographics list, the Brief COPE, and the Medical Outcome Study 36-Item Short-Form Health Survey.</p> <p>Results</p> <p>Hierarchical multiple regression analyses showed that older women who used behavioral disengagement and, to a smaller degree, self-distraction as a form of coping reported lower levels of general health. The opposite was the case for positive reframing and, to a lesser degree, substance use. Moreover, lower income was related to worse general health and (together with more advanced age) physical functioning. None of the coping strategies achieved significance in the physical functioning model.</p> <p>Conclusions</p> <p>These cross-sectional findings need corroboration by longitudinal research prior to developing related clinical interventions. Based on the initial evidence provided herein, clinicians working with this population should consider establishing the therapeutic goal of increasing the use of positive reframing while diminishing behavioral disengagement.</p

Gastrostomia endoscópica em pacientes com cardiopatia complicada Percutaneous endoscopic gastrostomy in cardiologic complicated patients

Pacientes cardiopatas complicados com isquemia cerebral e insuficiência cardíaca necessitam terapia nutricional enteral prolongada por se apresentarem em situação de risco nutricional. Complicações advindas do uso prolongado da sonda nasoenteral poderiam ser evitadas com a execução da gastrostomia endoscópica. Esta é alternativa técnica para acesso ao tubo digestivo em nutrição enteral. O objetivo deste estudo foi avaliar o tempo de indicação para gastrostomia endoscópica em pacientes com nutrição enteral com uso de sonda nasoenteral e as principais complicações do procedimento. Doze pacientes foram submetidos a gastrostomia endoscópica, sendo oito do sexo masculino. A idade média foi de 62,42 + 22,10 anos. A indicação principal foi síndrome isquêmica cerebral após parada cardiorespiratória por patologia clínica (sete pacientes) ou cirurgia cardiovascular complicada (cinco). O tempo médio para indicação da gastrostomia endoscópica foi de 35,58 + 26,79 dias após introdução da nutrição enteral. Não houve intercorrências com o procedimento e, no período pós-operatório tardio, ocorreu infecção do orifício de inserção da gastrostomia endoscópica em um caso, resolvida com cuidados locais. Em conclusão, a gastrostomia endoscópica é técnica segura, com baixa incidência de complicações. Pode ser realizada em ambulatório, no leito do paciente, ou em centro de terapia intensiva e sua indicação deveria ser mais precoce.<br>Complicated cardiologic patients with brain ischemia and heart failure need long term enteral nutrition. Long term nasoenteral tuibe feeding may cause complications that could be avoided with percutaneous endoscopic gastrostomy. The aim of this study was to evaluate the indications for percutaneous endoscopic gastrostomy and its main complications. Twelve patients were submitted to percutaneous endoscopic gastrostomy (eight male) with main age of 62,42 ± 22,10 years old. Brain ischemia was the main indication of percutaneous endoscopic gastrostomy and occurred after 35,58 ± 26,79 days, after iniciated enteral nutrition. There were no complications during procedure. On late post operatory period there were local infection in one cases, treated with local care. In conclusion, percutaneous endoscopic gastrostomy is a secure technique with low incidence of complications and its indication should be earlier