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In this paper, we introduce a numerical and analytical study of the HIV‐1 infection of CD4+ T‐cells conformable fractional mathematical model. This model is studied analytically by Kudryashov and modified Kudryashov methods and numerically by finite difference method. A comparison between the results of the analytical and numerical methods is investigated. We also give some figures that show how accurate the solutions will be obtained from analytical and numerical methods. [ABSTRACT FROM AUTHOR]

• Two numerical methods are developed for solving the fractional-order HIV-1 infection model of CD4 + T-cells. • Two method (Bessel matrix method and Bessel quasilinearization method) are based on the novel Bessel polynomials. • Error and convergence analysis are studied. • Numerical applications and comparisons show that methods are effective. • In the comparison of the two methods used, the Bessel-QLM method gives better results. In this paper, two numerical methods based on the novel Bessel polynomials are developed to solve the fractional-order HIV-1 infection model of CD 4 + T-cells considering the impact of antiviral drug treatment. In first of these methods, by using the Bessel polynomial and collocation points, we transform the HIV problem into a system of nonlinear algebraic equations. And this method, which is the method of direct solution is called as Bessel matrix method. The second method, which is called the Bessel-QLM method converts firstly HIV problem to a sequence of linear equations by using the technique of quasilinearization and then the reduced problem is solved by the direct Bessel matrix method. Error and convergence analysis are studied for the Bessel method. Finally, the applications are made on the numerical examples and also the numerical results are compared with the results of other available techniques. It is observed from applications that the presented results are better than the results of other existing methods and also the Bessel-QLM method is more efficient than the direct Bessel method. [ABSTRACT FROM AUTHOR]

Abstract: It has been reported that treatment with tricin (4′,5,7-trihydroxy-3′,5′-dimethoxyflavone), a derivative of Sasa albo-marginata, after human cytomegalovirus (HCMV) infection significantly suppressed both infectious virus production and HCMV replication in the human embryonic fibroblast cell line MRC-5. In this paper, we examined the mechanisms for the anti-HCMV effects of tricin in MRC-5 cells. Exposure of fibroblasts to tricin inhibited infectious HCMV production, with concomitant decreases in levels of transcripts of the CXC chemokine IFN-inducible T cell alpha chemoattractant (I-TAC or CXCL11) gene. We also found that the transcripts of the HCMV immediate early (IE) gene and replication of HCMV were lower in CXCL11 gene-knockdown cells. These results suggest that tricin is a novel compound with potential anti-HCMV activity and that CXCL11 is one of the chemokines involved in HCMV replication. In addition, it is possible that CXCL11 is the one of the targets of tricin. [Copyright &y& Elsevier]

Due to stable incidence and improved survival rates, there are an increasing number of patients living with HIV/AIDS in the USA. Although highly effective, current antiretroviral therapies are associated with a variety of side effects. The role side effects play on health outcomes has not been fully examined. The current study assessed the association of medication side effects with (1) self-assessed health status; (2) work productivity and activity impairment; and (3) healthcare resource utilization. Data were from a cross-sectional patient-reported survey fielded in the USA using a dual methodology of Internet and paper questionnaires. A total of 953 patients living with HIV/AIDS who were currently taking a medication for their condition were included in the analyses. The most frequent side effects reported by patients were fatigue (70.72%), diarrhea (62.96%), insomnia (58.97%), dizziness (52.78%), neuropathy (52.68%), joint pain (52.36%), nausea (51.63%), and abdominal pain (50.37%). The presence of each side effect was associated with reduced self-assessed health status, increased productivity loss, increased activity impairment, and increased healthcare resource use. Controlling for CD4 cell counts in regression modeling did little to diminish the impact of side effects. Although not all side effects were associated with all outcomes, every side effect was associated with worse health status, some measure of increased work productivity loss, and/or some measure of increased healthcare resource use. Patients are living longer with HIV and, therefore, spending a greater length of time on treatment. The results of the current study suggest that many of these patients are experiencing a wide array of side effects from these therapies. These side effects have demonstrated a profound association with self-assessed health, work productivity, and healthcare resource use. Improved management of these side effects or development of treatments with a better side effect profile may have a substantial humanistic and economic benefit. [ABSTRACT FROM AUTHOR]

Patients with chronic hepatitis C virus (HCV) can develop systemic cryoglobulinemic vasculitis. Combination of pegylatedinterferon α and ribavirin is the first-line treatment of this condition. However, in case of severe or life-threatening manifestations, absence of a virological response, or autonomized vasculitis, immunotherapy (alone or in addition to the antiviral regimen) is necessary. Rituximab is to date the only biologic with a sufficient level of evidence to support its use in this indication. Several studies have demonstrated that rituximab is highly effective when cryoglobulinaemic vasculitis is refractory to antiviral regimen, that association of rituximab with antiviral regimen may induce a better and faster clinical remission, and, recently, that rituximab is more efficient than traditional immunosuppressive treatments. Some issues with regard to the optimal dose of rituximab or its use as maintenance treatment remain unsolved. Interestingly, in balance with this anti-inflammatory strategy, a recent pilot study reported the significant expansion of circulating regulatory T lymphocytes with concomitant clinical improvement in patients with refractory HCV-induced cryoglobulinaemic vasculitis using low dose of subcutaneous interleukin-2. This paper provides an updated overview on the place of immunotherapy, especially biologics, in the management of HCV-induced cryoglobulinaemic vasculitis. [ABSTRACT FROM AUTHOR]

Early identification and management of treatment failure on highly active antiretroviral therapy (HAART) is crucial in maintaining a sustained response to therapy in HIV infection. However, HIV viral load (VL) and resistance testing, and second-line HAART regimens, are unaffordable to many patients in India, leaving them with limited treatment options. Predictors and reasons for antiretroviral switching, therefore, are likely to differ in settings of varying resources. A one-year, observational study of patients receiving antiretroviral therapy was conducted in a private, non-profit hospital in Bangalore. This paper examines the predictors and consequences of antiretroviral treatment switching in this setting and explores reasons for switching in a subset of patients. Data on demographics, drug regimens, adherence, and physical and psychosocial outcomes were collected quarterly. Tests of VL and CD4 cell counts were performed every six months. One-third of the patients switched therapy during the study period. Baseline predictors of switching included lower CD4 cell counts and more physical symptoms. Contrary to studies in other settings, a high VL did not predict treatment switching, and only a minority of those experiencing drug failure were switched to second-line regimens. Both groups (switchers and non-switchers) improved significantly over time with respect to CD4 counts and psychological well-being, and showed a reduction in physical and depressive symptoms. Any differences between the groups were no longer significant at the end of the study, once we controlled for baseline levels. Clinical, policy, and research implications of these findings are discussed within the context of resource-limited settings. [ABSTRACT FROM AUTHOR]

In Vietnam, ARV access has been scaled up since 2005 in high HIV prevalence areas in order to meet increasing demands for HIV treatment. This paper aims to estimate ARV unmet need and its associated socio-demographic characteristics among HIV-positive women in Haiphong, Vietnam. A cross-sectional study using structured questionnaires and CD4 cell count was conducted with 353 HIV-positive women recruited from groups of people living with HIV/AIDS (PLWHA), by snowball technique through member of PLWHA groups and the local AIDS management system (Provincial AIDS Center (PAC)). The percentage of HIV-positive women having an unmet ARV need was estimated to be 40%, particularly high among women who were not registered at PAC. Having an unmet ARV need was associated with not participating in PLWHA groups (OR 6.5; 2.4-17.2) and being younger than 30 years old (OR 2.9; 1.1-7.3). [ABSTRACT FROM AUTHOR]

Recommended treatment of chronic hepatitis B with interferon-a and/or nucleos(t)ide analogues does not lead to a satisfactory result. Induction of HBV-specific T cells by therapeutic vaccination or immunotherapies may be an innovative strategy to overcome virus persistence. Vaccination with commercially available HBV vaccines in patients did not result in effective control of HBV infection, suggesting that new formulations of therapeutic vaccines are needed. The woodchuck (Marmota monax) is a useful preclinical model for developing the new therapeutic approaches in chronic hepadnaviral infections. Several innovative approaches combining antiviral treatments with nucleos(t)ide analogues, DNA vaccines, and protein vaccines were tested in the woodchuck model. In this paper we summarize the available data concerning therapeutic immunization and gene therapy using recombinant viral vectors approaches in woodchucks, which show encouraging results. In addition, we present potential innovations in immunomodulatory strategies to be evaluated in this animal model. [ABSTRACT FROM AUTHOR]

Abstract: Mathematical models of HIV therapy have traditionally amalgamated the action of antiretroviral drugs, trading the complexity of the situation in favour of simpler—and hence mathematically tractable—models. However, the effects of ignoring such dynamics remain underexamined. In this paper, the traditional method of dosing (where the dose is modelled implicitly as a proportional inhibition of viral infection and production) is compared to a model that accounts for drug dynamics via explicit compartments. Four limiting cases are examined: frequent dosing of both major classes of drugs, absence of either drug, frequent dosing of one drug alone, or frequent dosing of the other drug alone. When drugs are absent, both models predict that the virus will dominate and the uninfected T cell counts will be low. When reverse transcriptase inhibitors are given frequently, both models predict that the virus will be theoretically eliminated and the uninfected T cell counts will be high; this is true regardless of whether the reverse transcriptase inhibitors act alone or in conjunction with protease inhibitors. However, if protease inhibitors alone are given frequently, then the implicit model predicts that the virus will be eliminated and the uninfected T cell counts will be high, whereas the (more realistic) explicit model predicts that the reverse situation may occur. In the latter case, critically, protease-only regimens may ultimately result in the death of the patient. It follows that the impact of drug regimens consisting only of protease inhibitors must be urgently re-examined, if such outcomes have been based on overly simplistic modelling. [Copyright &y& Elsevier]

In this paper, neglecting the effects of free virus, we consider a simple model of cell-to-cell spread of HIV-1. We discuss the impact of the CD8+ cell non-cytotoxic anti-viral response (CNAR) and cytotoxic T lymphocyte (CTL) activity on infection by HIV-1. Two types of models are considered: the ordinary differential equation (ODE) model and the discrete time delay differential equation (DDE) system. The steady states of the ODE model are globally asymptotically stable respectively under two threshold criteria. In the DDE model, the global stability of the infected steady state of the ODE model becomes only ultimately stable. Moreover, at a certain interval of the time delay, the DDE model will produce Hopf bifurcation or periodic solutions. The introduction of CTL and CNAR will change the values of these steady states and induce fluctuations in the cell concentration. It also affects the critical value of the time delay and is of utility in the interpretation of typical HIV-dynamics data resulting from clinical trials. The DDE model produces sustained infective oscillations in some real parameter values, which is different from the result of the similar cell-free viral spread model with delay. [ABSTRACT FROM AUTHOR]

The failure of highly active antiretroviral therapies (HAART) is mainly due to the existence of latent infected reservoirs, such as macrophages and resting CD4+ T cells. In this paper, we report the results that we obtained in a murine model of AIDS by alternating the administration of the lympholitic drug 2-Fluoro-ara-AMP (Fludarabine) to eliminate the infected cells, with that of Azidothymidine (AZT) plus reduced glutathione (GSH) encapsulated in erythrocytes, to protect lymphocytes and macrophages not yet infected, respectively. Two groups of infected mice were treated as follows: one group was treated by alternating the administration of Fludarabine and AZT (treatment A), while the other group received the same treatment plus GSH-loaded erythrocytes given with AZT (treatment A + L–RBC). Fludarabine was administered intraperitoneally, AZT in the drinking water and GSH was encapsulated in erythrocytes by a procedure of hypotonic dialysis and isotonic resealing. The results obtained show that GSH-loaded erythrocytes provide additive effects in all the parameters examined. Alternation of a lympholitic drug and antiretroviral drug is effective in reducing the progression of murine AIDS. Addition of a system to protect macrophages provides additive effects in almost all the parameters considered, confirming that combination therapies aimed at protecting different infectable cell compartments are better than treatments protecting mainly lymphocytes. [ABSTRACT FROM AUTHOR]

Summary This paper examines the numerical and functional consequences of various stimuli on antiviral CD8+ T-cell memory using a mathematical model. The model is based upon biological evidence from the murine model of infection with lymphocytic choriomeningitis virus (LCMV) that the phenotype of immunological memory represents low-level responses driven by various stimuli, and the memory CTL population is partitioned between resting, cycling and effector cells. These subpopulations differ in their lifespan, their potential to mediate antiviral protection and in the stimuli needed for their maintenance. Three types of maintenance stimuli are examined: non-antigen-specific (bystander) stimulation, persisting antigen stimulation and reinfection-mediated stimulation. The modelling predicts that: (i) stable persistence of CTL memory requires the presence of either bystander or antigen-specific stimulation above a certain threshold depending on the sensitivity of memory CTL to stimulation and their life-span; (ii) a relatively low level of stimuli (approximately 104 fold less on a per CTL basis compared to acute infection) is needed to stabilize the expanded memory CTL population; (iii) the presence of CTL subsets in the memory pool of different activation states and lifespans ensures the robustness of memory persistence in the face of temporal variation in the low-level stimuli and; (iv) an ‘optimal’ population structure of the memory CTL pool, in terms of immediate protection, requires the presence of both activated cycling and effector CTL. For this, persisting antigen alone or synergistically with bystander signals provide the appropriate stimulation, so that the stimuli equivalent to approximately 30 p.f.u. of LCMV in the spleen are sufficient to maintain approximately 105–106 specific CTL in the memory pool. These observations are relevant both to our understanding of natural protective immunity... [ABSTRACT FROM AUTHOR]

This paper examines helper T-cell responses and antibody titres and isotypes following immunization with a peptide antigen in association with three different adjuvants. B10.A mice were primed with pigeon cytochrome c fragment 81-104 in association with the adjuvants complete Freund's adjuvant (CFA), incomplete Freund's adjuvant (IFA) and alum. Strong antibody responses, dominated by IgG1, were observed upon priming with CFA and IFA. In contrast, priming with alum induced a weak antibody response with little or no detectable antigen-specific IgG1. These differences did not correlate with differences in T-cell priming, as immunization with peptide in association with all three adjuvants induced comparable T-cell proliferative responses and frequencies of antigen-specific cells. In addition, no significant differences in iiiterleukin-2 (IL-2), interferon-gamma (IFN-γ) and IL-4 production could be found, suggesting that the adjuvants did not differentially affect Th1 and Th2 cells. [ABSTRACT FROM AUTHOR]

HIV-1 persistence in long-lived cellular reservoirs remains a major barrier to a cure. In a recent Nature Medicine paper, Buzon et al. identify memory T cells with stem cell-like properties (TSCM) that harbor infectious provirus and that likely contribute to HIV-1 persistence. [ABSTRACT FROM AUTHOR]