Review of the toxicity effects of Stavudine (d4t) and Zidovudine (azt) in hepatocytes during HIV therapy.
Introduction
Since the outbreak of HIV/AIDS, an estimated 78 million people have acquired HIV and has killed approximately 39 million people infected with the virus. The prognosis of the epidemic has continued to vary from different countries and according to global statistics; 35 million people in 2013 were living with HIV/AIDS. 2.5 million People per annum acquire the virus and 1.5 million die of AIDS. Inspite of the drastic transmission of the HIV/AIDS epidemic, the development and accessibility of anti-retroviral drugs has decreased mortality rates by 22% from a population of 2.0million in 2009 to 1.5million in 2013 (WHO, 2013),
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Fig 1. Structure of HIV-1. Adopted from eMedWiki.
The HIV life cycle occurs in six stages namely; Fusion, Reverse transcription, Integration, transcription, assembly, and budding. Inorder for the virus to proceed to each stage and continue to replicate into new viral cells, it requires catalytic enzymes such as reverse transcriptase (RT), Intergrase (IG), and protease (PT). These replicating enzymes and cycle phases have been identified as potential therapeutic drug targets for HIV-therapy (Fig 2), therefore leading to the development of novel anti-retroviral drugs as stated below;
Fusion Inhibitors (FIs) and Entry inhibitors (EIs): They prevent entry of the viral capsid into the host CD4+ T cell, by inhibiting the viral Gp41 and Gp120 from binding and fusing with chemocokine coreceptors CCR5 or CXCR4 on the surface of the host cell. This further prevents the release of viral replicating enzymes (reverse transcriptase, Intergrase, and protease) from the viral capsid into the host cell. (Wilen et al., 2011). Examples are Enfuvirtide (FIs) and Maraviroc (EIs).
Reverse transcriptase Inhibitors (RTIs): There are 3 different classes of RTI and these include nucleoside RTIs (NRTIs), Non-nucleotide RTIs (NNRTIs), and nucleotide RTIs (NTRTIs). Inorder to exhibit their pharmacological effects,
Through the presentation of an extended metaphor from the beginning to the end of a text, a theme is expressed and deepened in Night. Elie Wiesel, the author of Night, is a Jew and a Holocaust survivor. He was born on September 30, 1928 in Sighet, Romania. In Night, he documents his experience during the Holocaust. He talks about his experiences in the camps and relationships he has with others.
On encountering a host cell, the retrovirus attaches itself to receptors on the surface of the host cell’s membrane. Once inside the cell, the capsid opens, releasing RNA and reverse transcriptase into the cell’s cytoplasm.
Since the arrival of triple therapy, the challenge of sustained and complete viral suppression has been solved for the majority of patients [1]. The major limiting factors for improving the long-term success of ART are tolerability and convenient pill burden [2]. The latest class of the antiretroviral drug developed are Integrase inhibitors (INI). Dolutegravir (DTG) is an Integrase inhibitor, particularly focused on maintaining a favorable safety profile and a high efficiency rate, within a single-tablet regime (STR), it improves resistance barrier and allowing co-formulation with an NRTI backbone. Dolutegravir has been compared against both other classes of HIV anti-retrovirals as well as other integrase nuclear strand inhibitors. In August 2013, DTG was approved by FDA for its use in both patients who have never taken ART (ART-naïve) and patients who have taken ART (ART-experienced) [3]. It is predicted that very soon a STR containing Dolutegravir (DTG), abacavir (ABC) and lamivudine (3TC) will become
HIV has evolved in new varieties over the last dozen years. The virus is constantly changing due to natural selection and the environment of the patient's body. Inside the body, HIV replicates and every time it reproduces, random genetic copying mistakes mutations result in slightly different varieties of the virus going into the bloodstream. Some of these varieties will have traits that will make them resistant to certain drugs. Natural selection favors the drug resistant forms, causing them to survive and reproduce while causing medication to not work. It was discovered in 1970, that a patient suffering with HIV whose medication did not work, by going off the drugs made his virus population soon change from being resistant to every drug to then being susceptible. This was caused by the environment change in the body when stopping the medication. The non-resistant wild-type came back and started to replicate and soon outnumbered the drug-resistant strains. This resulted in a new treatment used today. If you take a patient that is resistant to medication, off the drugs for a certain amount of time and the virus reverts to the non-resistance wild-type, then hit it hard with a combination of drugs.
We have been aware of HIV and AIDS since the 1970s (Miller, 2012), and though there have been treatments and reduction in the number of people infected, the disease remains. The disease results in death usually following opportunistic infections as a result of AIDS destruction of the immune system, but thanks to modern medicine “many people
“A Tree Grows in Brooklyn” by Betty Smith, is a novel that showcases the lives of a poor family living in Brooklyn and the people that are connected to them. The story revolves around a young girl Francie and about the different hardships her family and she goes through. The main theme of this book is tenacity and is shown by the many ways the Nolans find happiness.
b. HIV is an incurable disease that relies on coreceptors to initiate host cell interaction and proliferates by utilizing the host cell’s own machinery to reproduce new virus. We will more deeply explore the mechanism in which HIV virions infiltrate and deceive our host cell. In addition, we will discuss current treatment and research that are in the process of finding a highly coveted cure.
A disease is the destruction in the function of a human which leads to specific symptoms which in turn affects specific sites and are not results of physical injury. Protease cleaves longer proteins into shorter core proteins via proteolysis this is the process whereby hydrolysis of the peptide bonds occur that links subsequent amino acids to a polypeptide chain (Kohei Oda 2012). It is therefore crucial for the effectiveness of an infectious virus. Protease Inhibitors bind to the active sites of these proteases which in turn inhibits the passage of the protein from becoming shorter units (virions) in order to remain non-infectious. One such example is seen in the Human Immuno-defiency Virus commonly known HIV. In a video Dr. Rufus Rajadurai extensively explained the invasion process of the HIV virus into the uninfected cell of a human to the point of infection
Throughout this essay, I’ve mentioned the word recovery numerous time. As Miss New Jersey it is a community that I would like to embrace, with over 23 million Americans in recovery today. These individuals are always going to struggle with addiction, but they work daily to replace destructive habits with healthy new ones, in the attempt to mainstream sobriety. I will represent this community as a Recovery advocate promoting institutions such as recovery centers and recovery high schools, and provide New Jersians in recovery with the tools to sustain long-term recovery. We need to support those, in recovery so they can do so “out loud”, society should not discriminate against a community that is working daily to better their lives, in the attempt
Although ninety-five percent of people living with HIV/AIDS are in developing countries, the impact of this epidemic is global. In South Africa, where one in four adults are living with the disease, HIV/AIDS means almost certain death for those infected. In developed countries however, the introduction of antiretroviral drugs has meant HIV/AIDS is treated as a chronic condition rather than a killer disease. In developing countries like South Africa, the drugs that allow people to live with the disease elsewhere in the world, are simply too expensive for individuals and governments to afford at market price.
GDEPT is a two-step treatment strategy where the gene that encodes a prodrug-activating nonendogenous enzyme is selectively transferred to target tissues. The most commonly used gene delivery vectors are cationic lipids, peptides, and viral vectors (i.e., retroviruses, adenoviruses, and adeno-associated viruses). Subsequently, inactive prodrug is delivered systemically and converted to its active cytotoxic drug by the nonendogenous enzyme expressed in the target tissues. The effectiveness of GDEPT depends on several factors, including level of enzyme expression at the target site, prodrug activation efficiency, and the capability of the active cytotoxic drug to diffuse into adjacent cells. The most frequently used enzyme/prodrug systems include
The HIV-1 life cycle is complicated and its period and result is contingent upon the target cell type and cell activation. In the beginning, HIV-1 enters the cells without producing instant damage but by entering the cells it can provoke intracellular signal cascades, which may assist the progress of viral replication. The external glycoprotein (gp120) and the transmembrane protein (gp141) are two molecules on the HIV-1 envelope that form the spikes on the virion’s surface. In the entry process, gp120 first attaches to the CD4+ receptor and then attaches to the cell membrane. Interactions between the virus and chemokine co-receptors will cause permanent conformational changes. The fusion event will occur within minutes by pore formation and it will discharge the viral core into the cell cytoplasm. Once the core dismantles, the viral genome will be reverse transcribed into DNA by the virus’ own reverse transcriptase enzyme. Viral variants may develop at the time of this process because reverse transcriptase is error prone. During the midpoint of infection, both the viral protein integrase and the host DNA repair enzymes will inject the viral genome into the active domain of the host’s chromosomal DNA. Lens epithelium-derived growth factor (LEDGF/p75) is an integrase binding host factor that assists the progress of integration, which converts the cell into a virus producer. In the late stages, production of viral particles will need both host driven and virus driven
infected cells, have opened new avenues for strategies for HIV vaccine design” (39). These antibodies
Chemotherapeutic techniques have a range of side-effects that depend on the type of medications used. The most common medications affect mainly the fast-dividing cells of the body, such as blood cells and the cells lining the mouth, stomach, and intestines. Chemotherapy-related toxicities can occur acutely after administration, within hours or days, or chronically, from weeks to years.
Antisense-based therapeutics have attracted much interest as a novel class of agents for the treatment of ‘viral infections, cancers and genetic disorders due to their