Cytomegalovirus History, Biology and Treatment

Cytomegalovirus History, Biology and Treatment Historical Aspect Human CMV (HCMV) is a very common human DNA virus. Since the beginning of human life; it has co-evolved with its host (McGeoch et al., 1995). Although being a part of humankind, not everybody is infected (Alford et al., 1990). It was first isolated in 1956 by Smith where two strains were isolated from the salivary gland and kidney of two dying infants. Cytomegalic inclusion bodies had been found in both tissues. In 1957, Weller and colleagues isolated three strains of CMV from adenoid tissues of three asymptomatic children after surgical removal. Also in 1970, they isolated three other strains from liver biopsy and urine of three congenitally infected infants with CMV (Ho, 2008). In 1881, Ribbert was the first who observed the characteristic cells in the kidney of a stillborn infant but without interpretation of these observations and that was the first description of histologic features of infection (Naraqi, 1991). The first histopathological evidenve of CMV infection was identified in 1904 by Ribbert in tissues from a congenitally infected infant. Mistakenly the large inclusion-bearing cells observed at autopsy was assumed to be from protozoa. As a result, these cells were called protozoa like cells and many workers thought that they were protozoa. After that, the similiraties between these cells and those infected by Varicella-Zoster virus and Herpes simplex virus raised the suspicion of a viral cause. In 1920, Good pasture hypothesized the viral cause of such inclusions (Ho, 2008). The first name proposed for CMV was salivary gland virus or salivary gland inclusion disease virus. In 1921, Good pasture and Talbot used the word cytomegalia to describe the huge enlargement and alterations of infected cells. Such word was the origin of the term cytomegalovirus initially proposed by Weller and colleagues in 1960 (Weller and Hanshaw, 1962). The role of the virus as an important pathogen with different clinical manifestations was significantly identified during the 1970s and 1980s. The molecular biology, immunology, and antiviral therapeutic agents had been characterized. However, establishment of preventive strategies of CMV infection and determining the role of certain genes in viral pathogenesis still need more efforts (Sung and Schleiss, 2010). Classification Human CMV, designated as HHV5, is a member of the Herpesviridae family of viruses. It is one of the 8 human herpesviruses (HHV) (Schleiss, 2009). The Herpesviridae family is divided into three subfamilies designated ÃŽÂ ±, ÃŽÂ ², and ÃŽÂ ³. The classification into these subfamilies is based on the features of host range, duration of reproductive cycle, cytopathology and characteristics of latent infection. DNA sequence analysis, guanine and cytosine (G + C) content snd serologic reactivity of gene products are the main criteria for subdivision of each subfamily into genera (Hanley and Bollard, 2014). The ÃŽÂ ± subfamily includes herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) and varicella-zoster virus (VZV); the ÃŽÂ ² subfamily includes cytomegalovirus (CMV) and the roseolaviruses, human herpes viruses 6 and 7, which are responsible for the clinical syndrome of exanthem subitum (roseola infantum) in young children, and the ÃŽÂ ³ subfamily includes Epstein-Barr vir us and human herpes virus 8. All of these viruses share similarities in virion morphology and genome organization (Schleiss, 2009). Human herpesvirus classification is represented in table ( ) (Ryan and Ray, 2004). Table (1): Humah haerpesvirus (HHV) classificstion Type Synonym Subfamily Primary Target Cell Pathophysiology Site of Latency Means of Spread HHV-1 Herpes simplex virus-1 (HSV-1) ÃŽÂ ± (Alpha) Mucoepithelial Oral and/or genital herpes (predominantly orofacial), as well as other herpes simplex infections Neuron Close contact (oral or sexually transmitted infection) HHV-2 Herpes simplex virus-2 (HSV-2) ÃŽÂ ± Mucoepithelial Oral and/or genital herpes (predominantly genital), as well as other herpes simplex infections Neuron Close contact (sexually transmitted disease) HHV-3 Varicella zoster virus (VZV) ÃŽÂ ± Mucoepithelial Chickenpox and shingles Neuron Respiratory and close contact HHV-4 Epstein-Barr virus (EBV), lymphocryptovirus ÃŽÂ ³ (Gamma) B cells and epithelial cells Infectious mononucleosis, Burkitt lymphoma, CNS lymphoma in AIDS patients, post-transplant lymphoproliferative syndrome (PTLD), nasopharyngeal carcinoma, HIV-associated hairy leucoplakia B cell Close contact, transfusions, tissue transplant, and congenital HHV-5 Cytomegalovirus (CMV) ÃŽÂ ²(Beta) Monocyte, lymphocyte, and epithelial cells Infectious mononucleosis-like syndrome, retinitis, etc. Monocyte, lymphocyte, and? Saliva, urine, breast milk, etc HHV-6A and 6B Roseolavirus, Herpes lymphotropic virus ÃŽÂ ² T cells and ? Sixth disease (roseola infantum or exanthema subitum) T cell and ? Respiratory and close contact HHV-7 Pityriasis Rosea ÃŽÂ ² T cells and ? ? (roseola infantum or exanthema subitum) T cell and ? ? HHV-8 Kaposis sarcoma -associated herpesvirus (KSHV), a type of rhadinovirus ÃŽÂ ³ Lymphocyte, and other cells Kaposisarcoma, primary effusion lymphoma, some types of multicentric Castlemans disease B cell Close contact (sexual), saliva? Quoted from (Ryan and Ray , 2004). Biology of Cytomegalovirus Morphology: Cytomegalovirus is an enveloped virus with a double-stranded DNA genome. The three distinct regions of the CMV virus particle include: an icosahedral capsid; the tegument layer; and an outer lipid envelope. The morphology of CMV is demonstrated in the electron microscopy (EM) studies shown in Fig. (). The capsid, which comprises 162 capsomere subunits arranged in an icosahedral symmetry, houses the viral genome, and is classically highly electron-dense when imaged by EM (Schleiss, 2011). In the virus particle, the capsid is surrounded by the tegument, a protein-rich layer containing several of the dominant targets of the T-lymphocyte response to infection, including a 65-kilodalton (kDa) phosphoprotein (pp) referred to as pp65 (Kern etal., 2002). Surrounding the tegument is the envelope layer which contains several virally-encoded glycoproteins (g), including protein complexes designated as the gB complex, the gM/gN complex, and the gH/gL/gO complex. CMV-seropositive individuals mount an immune response characterized by neutralizing antibodies that target these glycoproteins (Bernstein, 2011). In addition to serving as targets of the humoral immune response, these glycoproteins also play a central role in the binding and entry of CMV into cells (Ryckman etal., 2006). Â   Â   As a result of the variability in the thickness of the tegument, the complete virion varies in size from 150 to 200 nm in diameter. The genome is about 64 nm in diameter with a molecular weight of 100 x 106 to 150 x 106. The capsid is 110 nm in diameter (Subhendu et al., 2007). During the process of viral replication, a variety of types of CMV particles are generated. In cell culture, CMV infection leads to the assembly and release of, in addition to infectious virions, non-infectious defective particles termed dense bodies (DB), so designated because of their characteristic highly electron-dense appearance when imaged by EM. Another type of body, designated as a noninfectious enveloped particle (NIEP), is also generated during viral replication as designated in Fig. () (Pepperl etal., 2000). The structure and protein composition of NIEPs are comparable to those of virions, but they lack DNA and are therefore not infectious (Schleiss, 2011). DBs are enveloped spherical structures that lack capsid proteins and DNA (Pepperl etal., 2000). They consist mainly of viral tegument proteins and glycoproteins. In cell culture, the biology of DBs mimics that of infectious virus, since DBs enter cells efficiently and deliver their protein components intracellularly (Me rsseman etal., 2008). In principle, DBs could induce a broad range of humoral and cellular immune responses (Schleiss, 2011). Cytomegalovirus particles exhibit additional levels of complexity. Using CMV gene array technology, a class of viral RNA transcripts, termed virion RNAs, has been identified in infectious virions (Bresnahan and Shenk, 2000). These RNAs, which are packaged during virion assembly, are delivered to the host cell immediately on infection, potentially allowing viral gene products to be expressed in an infected cell before any viral transcription or host immune response occurs. The role of virion

Human Element Essay

This study is related to an important topic that influence the evolution of both public and private institutions via improving human resource management and, hence improving the human resource itself, which occupies a vital and outstanding position in the comprehensive development strategies. Also, because of the role that effective human resource plays in planning and implementing development. Therefore, human element is considered an investment in the bright future of the institutions. Human resource is an innovative element that is described as an interactive rather than a rigid element, which is able to coordinate, maintain a balance between the various constituent of production and take the responsibility for the results of operations. On the other hand, external circumstances, such as the economic, political, social cultural and environmental factors, affect human element more than any other element. The researcher has selected Giad Automobiles Manufacturing Co. LTD, as a case study to introduce the influence of human resource development on employees’ performance. The results have been determined based on the analysis of the employees’ responses to the questionnaire that surveyed the employees’ community in the company. The questionnaire has tested the following hypotheses: 1- There is a relationship between the development of human resource management and the development of the working human element. 2- There is a relationship between the development of the human element and the development and improvement of performance in the institution, which leads to an increase in the production and, hence achieving the objectives. The researcher has applied several methodologies, such as case study methodology, descriptive methodology, and statistical analysis. The researcher has confirmed the validity of all the above hypotheses, in addition to the research outcomes that have led the researcher to conclude the study with some suggestions and recommendations.

The Never Before Told Story About Never Give up Essay Samples That You Need to Read

The Never Before Told Story About Never Give up Essay Samples That You Need to Read The Benefits of Never Give up Essay Samples They have to make sure that they brainstorm and have a plan before they begin to write. Anyway, in attempting to reach your aims, you may find out that perhaps your targets aren't correct or not practical whatsoever, then it is possible to improve them and make your life more beautiful. It is crucial to manage or budget your time to steer clear of difficulties in writing. I am unable to forget this wonderful group of students that are also my buddies. You may be a freshman in that feeling that you don't know the school really well and you don't have any friends in the school. Students have a challenging time in writing if they don't have a draft or outline to follow. Therefore, many students and employees decide to acquire inexpensive essay rather than writing it themselves. You ought to take notes and read it again so that you become additional information and you know what things to write in the essay. Do your best in writing the essay and be sure that you aren't going to incorporate any opinions. As a writer, you compose an essay for any given purpose. Persuasive essays are intended to be convincing, this might be to obtain a given product or maybe to earn a call to action. Every paragraph must cover 1 topic in making the circulation of the essay smooth. The wording has to be clear and concise. I believe this statement is true since you can be whatever you wish to be, you merely have to set your mind to it and work for it. Make sure you own a thesis statement and topic sentences for every single paragraph. Maybe it is a coincidence. Never assume that the significance of a sentence is clear. His words are almost always strong with me. You're not a word with a particular meaning. Never Give up Essay Samples The samples will provide you with ideas on the way you answer the questions offered to you. There are hundreds and hundreds of sample resumes on the world wide web. In here, you shouldn't introduce any new info. The info has to have an excellent flow. Citations and extracts from several sources have to be formatted properly. Your thesis ought to be limited to what can be achieved in the designated range of pages. Also, you can look for sample expository essay topics so you will be aware of what to research and that which you will deal with. You don't need to agree with each assessment or edit, but you need to be open to constructive criticism. And this isn't the close of the story yet. Everything takes time, you simply must be patient. Following are 35 quotes it is possible to read the next time you feel like you would like to give up. Perseverance is essential for all Christians to get. Another instance of the value of perseverance is found in The Holy Bible. 3 Life isn't a bed of roses. Folks wish to write something free of charge. You may not be able to set up your own company yet, but you are merely collecting experience and knowledge as a great manager, and maybe in 10 decades, you will turn into the boss of your own firm. This may be the most significant advantage of not giving up. The millionaires or billionaires we see today aren't a product of a single day. Many restaurants in various countries forbid their staff to just accept advice since they already offer sufficient wages for them.

Study Tips for Math Homework and Math Tests

There are several ways to study math. Some students need to use as many practice questions as possible, while other students can benefit by listening to the math lecture over and over. Find out which math tips help you most. Study Tips for Math at Home Make photocopies of textbook problems. Math books give you sample problems to solve, but they often dont give you enough similar problems to help you understand a process. You can photocopy or scan a page with good samples and re-work the problems several times, perhaps once a day. By solving the same problems over and over, youll better understand the processes that you go through.Buy used textbooks.  Sometimes we dont understand a concept because the explanation is just plain bad or its not written in a way we can understand. Its good to have an alternate text that gives alternate explanations and additional sample problems to work out. Many used bookstores will have inexpensive texts.Study actively.  Dont just work out a problem. Draw pictures and diagrams of a process and make up stories to go along with them. If you are an auditory learner you may want to make brief recordings of yourself defining some terms or processes. Read about helpful​ tactile learning tips  a nd  visual learning tips.Read actively.  Use sticky note flags to mark important things in your chapter or things you need to ask about in class. If you have a sample problem that youve worked out and youd like to have similar problems for additional practice, mark it with a flag and ask the teacher in class. Read the end of your assigned chapter first. Take a look at the problems youll be solving to get a preview of your goals. This gives your brain a framework to work with.Make flashcards for terms.  Flashcards are good for visual and tactile learners. They reinforce information as you see it and as you create it with your own hand.Use college prep study guides.  If you cant find an old textbook to use in addition to your class text, try using an SAT, ACT, or CLEP study guide. They often provide great explanations and sample problems. You can also find free online study guides for these tests.Take breaks.  If you come across a problem that you dont understand, read it ov er a few times and try—but then walk away from it and make a sandwich or do some other small task (not other homework). Your brain will continue to work on the problem subconsciously. Study Tips for Math in Class Review yesterdays notes before class.  In the minutes before class starts, look over notes from yesterday. Determine if there are any sample problems or concepts you should ask about.Record lectures.  If the teacher allows it, record your class. You will often find that you miss small steps in your notes or you dont quite pick up on an explanation that the teacher gives. A class recording will pick up everything. Auditory learners will really benefit from listening. Remember, just because your math class lasts 45 minutes, dont think youre going to end up with 45 minutes of lecture to listen to. Youll find that the actual talking time is about 15 minutes.Ask for extra sample problems.  Ask your teacher to solve sample problems. Thats a teachers job! Dont let a topic go by if you dont get it. Dont be shy.Draw anything the teacher draws.  If the teacher makes a drawing on the board, you should always copy it. Even if you dont think its important at the time or you dont understan d it at the time. You will! Study Tips for Math Tests Review old tests.  Old tests are the best clues to future tests. They are good for establishing a strong foundation for the newer information, but they also provide insight as to how the teacher thinks.Practice neatness.  How unfortunate would it be to miss a test question out of sloppiness? Its important to make sure you can line up problems neatly so you dont confuse yourself, and also to make sure you can tell your sevens from your ones.Find a study partner.  Youve heard it before, but its worth repeating. A study partner can test you and help you understand things you cant get on your own.Understand the process.  You sometimes hear that it doesnt matter how you come up with the right answer, just as long as you get there. This is not always true. You should always strive to understand an equation or a process.Is it logical?  As you work out a story problem, always give your answer the logic test. For example, if you are asked to find the speed of a car traveling between two distances, you are probably in trouble if your answer is 750 mph. Apply the logic test as you study so you dont repeat a faulty process during your test. xnynznx^{n} y^{n} z^{n} xn yn zn