scholarly journals A generalized distributed delay model for HBV infection with two modes of transmission and adaptive immunity: A mathematical study

2021 ◽  
Author(s):  
Kalyan Manna ◽  
khalid hattaf
Keyword(s):  
Adaptive Immunity ◽  
Distributed Delay ◽  
Hbv Infection ◽  
Infection Model ◽  
Delay Model ◽  
Cell Infection ◽  
Modes Of Transmission ◽  
Proposed Model ◽  
Infection Models ◽  
B Virus

In this paper, we formulate a generalized hepatitis B virus (HBV) infection model with two modes of infection transmission and adaptive immunity, and investigate its dynamical properties. Both the virus-to-cell and cell-to-cell infection transmissions are modeled by general functions which satisfy some biologically motivated assumptions. Furthermore, the model incorporates three distributed time delays for the production of active infected hepatocytes, mature capsids and virions. The well-posedness of the proposed model is established by showing the non-negativity and boundedness of solu- tions. Five equilibria of the model are identified in terms of five threshold parameters R0, R1, R2, R3 and R4. Further, the global stability analysis of each equilibrium under certain conditions is carried out by employing suitable Lyapunov function and LaSalle’s invariance principle. Finally, we present an example with numerical simulations to il- lustrate the applicability of our study. Nonetheless, the results obtained in this study are valid for a wide class of HBV infection models.

scholarly journals Qualitative Analysis of a Generalized Virus Dynamics Model with Both Modes of Transmission and Distributed Delays

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Khalid Hattaf ◽  
Noura Yousfi
Keyword(s):  
Qualitative Analysis ◽  
Distributed Delays ◽  
Virus Dynamics ◽  
Dynamics Model ◽  
Cell Infection ◽  
Modes Of Transmission ◽  
Proposed Model ◽  
Infection Models ◽  
Infected Cells ◽  
Incidence Functions

We propose a generalized virus dynamics model with distributed delays and both modes of transmission, one by virus-to-cell infection and the other by cell-to-cell transfer. In the proposed model, the distributed delays describe (i) the time needed for infected cells to produce new virions and (ii) the time necessary for the newly produced virions to become mature and infectious. In addition, the infection transmission process is modeled by general incidence functions for both modes. Furthermore, the qualitative analysis of the model is rigorously established and many known viral infection models with discrete and distributed delays are extended and improved.

scholarly journals Dynamics of an HBV infection model with cell-to-cell transmission and CTL immune response

2019 ◽  
Vol Volume 30 - 2019 - MADEV... ◽  
Author(s):  
Hajar Besbassi ◽  
Zineb Elrhoubari ◽  
Khalid Hattaf ◽  
Yousfi Noura
Keyword(s):  
Chronic Infection ◽  
Hbv Infection ◽  
Infection Model ◽  
Geometrical Approach ◽  
Direct Lyapunov Method ◽  
Cell Infection ◽  
Modes Of Transmission ◽  
Cell Transmission ◽  
Infected Cells ◽  
Disease Free

International audience In this work, we propose a mathematical model to describe the dynamics of the hepatitis B virus (HBV) infection by taking into account the cure of infected cells, the export of precursor cytotoxic T lympho-cytes (CTL) cells from the thymus and both modes of transmission that are the virus-to-cell infection and the cell-to-cell transmission. The local stability of the disease-free equilibrium and the chronic infection equilibrium is obtained via characteristic equations. Furthermore, the global stability of both equilibria is established by using two techniques, the direct Lyapunov method for the disease-free equilibrium and the geometrical approach for the chronic infection equilibrium. Dans ce travail, nous proposons un modèle mathématique pour décrire la dynamique du virus d'hépatite B (HBV) en prenant en compte le taux de guérison de cellules infectées, l'exportation de précurseur cytotoxic des lymphocytes T (CTL) des cellules du thymus et les deux modes de transmission qui sont l'infection virus-à-cellule et la transmission cellule-à-cellule.La stabilité locale de l'équilibre libre et l'équilibre d'infection chronique est obtenue via des équations caractéristiques. En outre, la stabilité globale des deux équilibres est établie en utilisant deux techniques, la méthode directe de Lyapunov pour l'équilibre libre et l'approche géométrique pour l'équilibre d'infection chronique.

Retrotransposon elements among initial sites of hepatitis B virus integration into human genome in the HepG2-NTCP cell infection model

2019 ◽  
Vol 235-236 ◽  
pp. 39-56 ◽  
Author(s):  
Ranjit Chauhan ◽  
Yoshimi Shimizu ◽  
Koichi Watashi ◽  
Takaji Wakita ◽  
Masayoshi Fukasawa ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Human Genome ◽  
Infection Model ◽  
Cell Infection ◽  
B Virus ◽  
Virus Integration

scholarly journals Epidemiology of hepatitis B virus infection in the Middle East

2001 ◽  
Vol 7 (06) ◽  
pp. 1034-1045 ◽  
Author(s):  
N. Qirbi ◽  
A. J. Hall
Keyword(s):  
Middle East ◽  
Hepatitis B ◽  
Public Health Problem ◽  
Hbv Infection ◽  
Accurate Information ◽  
Carrier Status ◽  
Community Based ◽  
Modes Of Transmission ◽  
Middle East Countries ◽  
B Virus

Inthis article, the epidemiology of hepatitis B [HBV] infection in the Middle East is reviewed. The prevalence of HBV carrier status in the region is considered and the modes of transmission of infection discussed. The risk factors associated with HBV infection are examined and preventive measures against HBV infection in countries of the region are presented. The review is based on information from two sources-publications in the international literature on the epidemiology of HBV infection in Middle East countries, identified by searching MEDLINE and POPLINE, and Middle East country and regional reports on viral hepatitis. It is evident that HBV infection is a serious public health problem in the region and many questions specific to the region remain unanswered. Community-based surveys are recommended as they provide more accurate information that can be generalized than hospital-based surveys.

scholarly journals Advances in Animal Models of Hepatitis B Virus Infection

2015 ◽  
Vol 4 (4) ◽  
pp. 96-101 ◽  
Author(s):  
Hang Zhang
Keyword(s):  
Hepatitis B Virus ◽  
Animal Models ◽  
Virus Infection ◽  
Hepatitis B ◽  
Hepatitis Virus ◽  
Hbv Infection ◽  
Infection Model ◽  
Advantages And Disadvantages ◽  
Duck Hepatitis ◽  
B Virus

Abstract Hepatitis B virus (HBV) infection seriously affects human health. Stable and reliable animal models of HBV infection bear significance in studying pathogenesis of this health condition and development of intervention measures. HBV exhibits high specificity for hosts, and chimpanzee is long used as sole animal model of HBV infection. However, use of chimpanzees is strictly constrained because of ethical reasons. Many methods were used to establish small-animal models of HBV infection. Tupaia is the only nonprimate animal that can be infected by HBV. Use of HBV-related duck hepatitis virus and marmot hepatitis virus infection model contributed to evaluation of mechanism of HBV replication and HBV treatment methods. In recent years, development of human–mouse chimeric model provided possibility of using common experimental animals to carry out HBV research. These models feature their own advantages and disadvantages and can be complementary in some ways. This study provides an overview of current and commonly used animal models of HBV infection.

scholarly journals Global dynamics of a general diffusive HBV infection model with capsids and adaptive immune response

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
A. M. Elaiw ◽  
A. D. Al Agha
Keyword(s):  
Equilibrium Points ◽  
Adaptive Immune Response ◽  
Hbv Infection ◽  
Infection Model ◽  
Global Dynamics ◽  
Enveloped Viruses ◽  
Adaptive Immune ◽  
B Virus ◽  
Infected Liver ◽  
Theoretical Results

AbstractThis paper studies the global dynamics of a general diffusive hepatitis B virus (HBV) infection model. The model includes both enveloped viruses and DNA containing capsids. Two immune responses are recruited to attack the virus and infected hepatocytes. These are the cytotoxic T-lymphocytes (CTL) which kill the infected liver cells, and B cells which send antibodies to attack the virus. The non-negativity and boundedness of the solutions are discussed. The existence of spatially homogeneous equilibrium points is examined. The global stability of all possible equilibrium points is proved by choosing suitable Lyapunov functionals. Some numerical simulations are performed to enhance the theoretical results and present the behavior of solutions in space and time.

scholarly journals Stability and Hopf Bifurcation of a Generalized Chikungunya Virus Infection Model with Two Modes of Transmission and Delays

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hajar Besbassi ◽  
Khalid Hattaf ◽  
Noura Yousfi
Keyword(s):  
Hopf Bifurcation ◽  
Chikungunya Virus ◽  
Infection Model ◽  
Cell Infection ◽  
Chikv Infection ◽  
Modes Of Transmission ◽  
Functional Methods ◽  
Incidence Functions ◽  
Virus Infection Model ◽  
Disease Free

A generalized chikungunya virus (CHIKV) infection model with nonlinear incidence functions and two time delays is proposed and investigated. The model takes into account both modes of transmission that are virus-to-cell infection and cell-to-cell transmission. Furthermore, the local and global stabilities of the disease-free equilibrium and the chronic infection equilibrium are established by using the linearization and Lyapunov functional methods. Moreover, the existence of Hopf bifurcation is also analyzed. Finally, an application is presented in order to support the analytical results.

scholarly journals Hypoxic gene expression in chronic hepatitis B virus infected patients is not observed in state-of-the-art in vitro and mouse infection models

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Peter Jianrui Liu ◽  
James M. Harris ◽  
Emanuele Marchi ◽  
Valentina D’Arienzo ◽  
Thomas Michler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Hepatitis ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Chronic Hepatitis B ◽  
State Of The Art ◽  
Hbv Infection ◽  
Infection Models ◽  
B Virus

Abstract Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) worldwide. The prolyl hydroxylase domain (PHD)-hypoxia inducible factor (HIF) pathway is a key mammalian oxygen sensing pathway and is frequently perturbed by pathological states including infection and inflammation. We discovered a significant upregulation of hypoxia regulated gene transcripts in patients with chronic hepatitis B (CHB) in the absence of liver cirrhosis. We used state-of-the-art in vitro and in vivo HBV infection models to evaluate a role for HBV infection and the viral regulatory protein HBx to drive HIF-signalling. HBx had no significant impact on HIF expression or associated transcriptional activity under normoxic or hypoxic conditions. Furthermore, we found no evidence of hypoxia gene expression in HBV de novo infection, HBV infected human liver chimeric mice or transgenic mice with integrated HBV genome. Collectively, our data show clear evidence of hypoxia gene induction in CHB that is not recapitulated in existing models for acute HBV infection, suggesting a role for inflammatory mediators in promoting hypoxia gene expression.

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