5 results
Search Results
2. Global stability analysis of viral infection model with logistic growth rate, general incidence function and cellular immunity.
- Author
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Gharahasanlou, Tohid Kasbi, Roomi, Vahid, and Hemmatzadeh, Zeynab
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CELLULAR immunity , *GLOBAL analysis (Mathematics) , *CELL physiology , *BASIC reproduction number , *VIRUS diseases - Abstract
It is well known that the mathematical biology and dynamical systems give very important information for the study and research of viral infection models such as HIV, HBV, HCV, Ebola and Influenza. This paper deals with the global dynamics of generalized virus model with logistic growth rate for target cells, general incidence rate and cellular immunity. The results will be obtained by using Lyapunov's second method and LaSalle's invariance principle. We prove the global stability of the rest points of the system by the value of basic reproduction number (R 0) and the immune response reproduction number (R CTL). We have found that if R 0 < 1 , then the infection-free equilibrium is globally asymptotically stable. For R 0 > 1 and R CTL < 1 , under certain conditions on incidence rate function, immune-free equilibrium is globally asymptotically stable. Finally, we prove that if R 0 > 1 and R CTL > 1 , then under certain conditions on incidence rate function the endemic equilibrium is globally asymptotically stable. Since the logistic growth rate for target cells and general incidence rate have been included in this manuscript, our obtained results are the generalization of those in the previous literatures. Moreover, the results have been obtained with weaker assumptions in comparison with the previous ones. Numerical simulations are presented to support and illustrate our analytical results. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
3. A new simple fluorescent probe for imaging endogenous hydrogen peroxide in RAW 264.7 cells.
- Author
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Wei, Huiqin, Chen, Huijia, Liu, Shun, Tan, Meixia, Zhang, Zhiqiang, Xu, Xiuzhi, and Ke, Fang
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HYDROGEN peroxide , *FLUORESCENT probes , *REACTIVE oxygen species , *CELL motility , *CELLULAR immunity - Abstract
[Display omitted] One of the most significant species that are present in large quantities in biological cells is reactive oxygen species (ROS). They are essential for cell motility, cell differentiation, and cellular immunity. In this paper, we introduce that (E)-1-methyl-4-(4-(propionyloxy)styryl)pyridin-1-ium (MPSPI) is an "on" type fluorescent probe regulated by the ICT mechanism. After the addition of hydrogen peroxide, the fluorophore (E)-4-(4-hydroxystyryl)-1-methylpyridin-1-ium (HMI-OH) is released. The simple probe MPSPI not only exhibited good selectivity and low cytotoxicity, but also demonstrated a detection limit as low as 35 nM and reaction times as quick as 20 s. Moreover, it has been successfully applied to the imaging of hydrogen peroxide in RAW 264.7 cells. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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4. Size-dominated biotoxicity of microplastics laden with benzophenone-3 and ciprofloxacin: Enhanced integrated biomarker evaluation on mussels.
- Author
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Li, Junnan, Jong, Mui-Choo, Gin, Karina Yew-Hoong, and He, Yiliang
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PLASTIC marine debris ,MUSSELS ,MICROPLASTICS ,CIPROFLOXACIN ,BIOMARKERS ,CELLULAR immunity ,WATER pollution - Abstract
Microplastics (MPs) are emerging pollutants with diverse sizes in aquatic environments. This paper investigates the toxicity of micron- and nano-scale polystyrene (50 μm, 5 μm, 0.5 μm) loaded with 2-hydroxy-4-methoxy-benzophenone (BP-3) and ciprofloxacin (CIP) by eight biomarker responses in mussels, perna viridis. The mussels were exposed to MPs and chemicals for 7 days before 7 days of depuration. Eight biomarkers were measured to determine biotoxicity over time by using the weighted integrated biomarkers index evaluation (EIBR). Mussels exposed to MPs on a daily basis demonstrated a cumulative toxic effect. The toxicity of MPs for mussels was inversely related to the size at which they can be ingested. Then toxicity was reversed when exposure was halted. EIBR mold has shown a significant difference in the biotoxicity of each biological level under different exposure scenarios. In general, the mussel toxicity influenced by BP-3 and CIP exposure without an adsorbent was insignificant. MPs laden with them increased the toxicity of mussels. Under condition of lower concentration of ECs (Emerging contaminants), the presence of MPs as a component of a combined pollutant in water dominated the biotoxicity for mussels. The EIBR assessment further validated that the biotoxicity of mussels was size-dependent. Its application simplified the biomarkers' response index and enhanced the accuracy of evaluation by weighing on molecular, cellular and physiological level. Specifically, mussels were physiologically sensitive to nano-scale plastics, with nano-scale plastics causing a higher level of cellular immunity destruction and genotoxicity than micron-scale plastics. Enzymatic antioxidant systemswere upregulated based on size-differential plastics; however, the total antioxidant effect of non-enzymatic defenses appeared to be least affected by the size effect. [Display omitted] • Nano-scale plastics pose a greater threat to genotoxicity, immunotoxicity, and enzymatic antioxidant system. • MPs load BP-3 and CIP exposure causes a greater response than MPs exposure. • MPs transport chemicals into the internal circulatory to affect biological response. • EIBR corroborated increasing toxicity regulated by sizes of MPs. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Omicron variant infection and the associated immunological scenario.
- Author
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Goutam Mukherjee, Anirban, Ramesh Wanjari, Uddesh, Murali, Reshma, Chaudhary, Uma, Renu, Kaviyarasi, Madhyastha, Harishkumar, Iyer, Mahalaxmi, Vellingiri, Balachandar, and Valsala Gopalakrishnan, Abilash
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SARS-CoV-2 Omicron variant , *COVID-19 vaccines , *HUMORAL immunity , *CELLULAR immunity , *BOOSTER vaccines - Abstract
• The Omicron variant diminishes the neutralizing capability of the antibodies. • Omicron can easily bypass an individual's humoral immune response. • The Omicron variant has more than 50 mutations. • CD8 + T-cell response may show promise against the Omicron variant. The million-dollar question that has been the talk of the day is how effective the COVID 19 vaccines are against the Omicron variant. Still, there is no clear-cut answer to this question but several studies have concluded that this Variant of Concern (VOC) successfully weakens the neutralizing capability of the antibodies acquired from the COVID 19 vaccines and prior infections, which indicates that Omicron can easily bypass an individual's humoral immune response. However, the most significant confusion revolves around cell-mediated immunity tackling the Omicron variant. This paper aims to provide a clear idea about the status of the body's immune surveillance concerning the infection caused by the Omicron variant by producing the effectivity of the humoral and cell-mediated immunity in handling the same. This work also provides complete detail of the various characteristics of the Omicron variant and how it may be a blessing in disguise. The effectiveness of the current vaccines, the transmissibility rate of the variant compared to the other variants, and the importance of administering a booster dose to prevent the spread of this variant are also discussed. Finally, this work aims to bridge the gap between the past and the current status of the Omicron infection and sheds light on the hypothetical idea that herd immunity developed from the SARS-COV2 infection may help tackle other dangerous variants. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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