Kenneth Witwer
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Kenneth Witwer
Kenneth W. Witwer is an associate professor of molecular and comparative pathobiology and neurology at the Johns Hopkins University School of Medicine in Baltimore, Maryland, United States. As nominated President-Elect of the International Society for Extracellular Vesicles (ISEV), Witwer previously served as Secretary General and Executive Chair of Science and Meetings of the society. His laboratory studies extracellular vesicles (EVs), noncoding and extracellular RNA (exRNA), and enveloped viruses, including HIV and SARS-CoV-2. Witwer is a member of the Richman Family Precision Medicine Center of Excellence in Alzheimer's Disease, has advised the US Environmental Protection Agency and the US National Institutes of Health, and is an associate editor of the Journal of Extracellular Vesicles. Career and research Witwer's PhD dissertation research was on retroviruses and the innate immune system responses to pathogens such as Visna virus and simian immunodeficiency virus (SI ...
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Virology
Virology is the Scientific method, scientific study of biological viruses. It is a subfield of microbiology that focuses on their detection, structure, classification and evolution, their methods of infection and exploitation of host (biology), host cell (biology), cells for reproduction, their interaction with host organism physiology and immunity, the diseases they cause, the techniques to isolate and culture them, and their use in research and therapy. The identification of the causative agent of tobacco mosaic disease (TMV) as a novel pathogen by Martinus Beijerinck (1898) is now acknowledged as being the history of virology, official beginning of the field of virology as a discipline distinct from bacteriology. He realized the source was neither a bacterial nor a fungal infection, but something completely different. Beijerinck used the word "virus" to describe the mysterious agent in his 'contagium vivum fluidum' ('contagious living fluid'). Rosalind Franklin proposed the f ...
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Environmental Protection Agency
A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale from microscopic to global in extent. It can also be subdivided according to its attributes. Examples include the marine environment, the atmospheric environment and the terrestrial environment. The number of biophysical environments is countless, given that each living organism has its own environment. The term ''environment'' can refer to a singular global environment in relation to humanity, or a local biophysical environment, e.g. the UK's Environment Agency. Life-environment interaction All life that has survived must have adapted to the conditions of its environment. Temperature, light, humidity, soil nutrients, etc., all influence the species within an environment. However, life in turn modifies, in various forms, its conditions. ...
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Advances In Experimental Medicine And Biology
''Advances in Experimental Medicine and Biology'' is a peer-reviewed book series. It covers the broad fields of experimental medicine and biology. The series was established in 1967 and is published by Springer Nature. The editors-in-chief are Wim E. Crusio (French National Centre for Scientific Research and University of Bordeaux), Haidong Dong ( Mayo Clinic), Heinfried H. Radeke (Goethe University), Nima Rezaei (Tehran University of Medical Sciences), Ortrud Steinlein ( Ludwig Maximilian University of Munich), and Junjie Xiao (Shanghai University). Abstracting and indexing The series is abstracted and indexed in: *BIOSIS Previews * Embase *Index Medicus/MEDLINE/PubMed * Science Citation Index Expanded *Scopus According to the ''Journal Citation Reports'', the series has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations ...
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Richman Family Precision Medicine Center Of Excellence In Alzheimer’s Disease
Richman as a surname may refer to: * Adam Richman (born 1974), host of the Travel Channel's ''Man v. Food'' * Adam Richman (singer) (born ca. 1983), American indie pop singer-songwriter * Alfred A. Richman (c. 1892 - December 8, 1984), orthopedic surgeon * Boomie Richman (1921–2016), American saxophone player * Caryn Richman (born 1956), American actress * Chaim Richman, rabbi in Israel * Charles Richman (commissioner), American community affairs worker * Charles Richman (actor) (1865–1940), American film actor * David Richman (born 1978), American basketball head coach * Douglas Richman (born 1943), American medical virologist * Frank Richman (1881–1956), Justice of the Indiana Supreme Court * Harry Richman (1895–1972), American entertainer * Ike Richman (1913–1965), American attorney and sports executive) * Jeffrey Richman, American writer, producer and actor * John Henry Richman (1791–1864), South Australian lawyer * Jonathan Richman (born 1951), American indie musici ...
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Biomarker
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. as cited in Biomarkers are used in many scientific fields. Medicine Biomarkers used in the medical field, are a part of a relatively new clinical toolset categorized by their clinical applications. The three main classes are molecular biomarkers, cellular biomarkers or imaging biomarkers. All three types of biomarkers have a clinical role in narrowing or guiding treatment decisions and follow a sub-categorization of being either predictive, prognostic, or diagnostic. Predictive Predictive molecular, cellular, or imaging biomarkers that pass validation can serve as a method of predicting clinical outcomes. Predictive biomarkers are used to help optimize id ...
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Promyelocytic Leukemia Protein
Promyelocytic leukemia protein (PML) (also known as MYL, RNF71, PP8675 or TRIM19) is the protein product of the PML gene. PML protein is a tumor suppressor protein required for the assembly of a number of nuclear structures, called PML-nuclear bodies, which form amongst the chromatin of the cell nucleus. These nuclear bodies are present in mammalian nuclei, at about 1 to 30 per cell nucleus. PML-NBs are known to have a number of regulatory cellular functions, including involvement in programmed cell death, genome stability, antiviral effects and controlling cell division. PML mutation or loss, and the subsequent dysregulation of these processes, has been implicated in a variety of cancers. History PML was poorly understood until described in the findings of Grignani ''et al'' in their 1996 study of patients with acute promyelocytic leukemia (APL). It was found that the karyotype of 90% of APL patients included a reciprocal translocation, resulting in the fusion of the Retinoic A ...
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Cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine, paracrine and endocrine signaling as immunomodulating agents. Cytokines include chemokines, interferons, interleukins, lymphokines, and tumour necrosis factors, but generally not hormones or growth factors (despite some overlap in the terminology). Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. They act through cell surface receptors and are especially important in the immune system; cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and res ...
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MicroRNA
MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRNAs base-pair to complementary sequences in mRNA molecules, then gene silence said mRNA molecules by one or more of the following processes: (1) cleavage of mRNA strand into two pieces, (2) destabilization of mRNA by shortening its poly(A) tail, or (3) translation of mRNA into proteins. This last method of gene silencing is the least efficient of the three, and requires the aid of ribosomes. miRNAs resemble the small interfering RNAs (siRNAs) of the RNA interference (RNAi) pathway, except miRNAs derive from regions of RNA transcripts that fold back on themselves to form short hairpins, whereas siRNAs derive from longer regions of double-stranded RNA. The human genome may encode over 1900 miRNAs, although more recent analysis suggests that ...
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Human Immunodeficiency Virus
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause AIDS, acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype. In most cases, HIV is a sexually transmitted infection and HIV/AIDS#Transmission, occurs by contact with or transfer of blood, pre-ejaculate, semen, and Vaginal lubrication, vaginal fluids. Non-sexual transmission can occur from an infected mother to her infant during pregnancy, during childbirth by exposure to her blood or vaginal fluid, and through breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected White blood cell, immune cells. Research has shown (for both same-sex ...
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Simian Immunodeficiency Virus
''Simian immunodeficiency virus'' (''SIV'') is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was isolated from the mainland by rising sea levels about 11,000 years ago, it has been concluded that SIV has been present in monkeys and apes for at least 32,000 years, and probably much longer. Virus strains from three of these primate species, SIVsmm in sooty mangabeys, SIVgor in gorillas and SIVcpz in chimpanzees, are believed to have crossed the species barrier into humans, resulting in HIV-2 and HIV-1 respectively, the two HIV viruses. The most likely route of transmission of HIV-1 to humans involves contact with the blood of chimps and gorillas that are often hunted for bushmeat in Africa. Four subtypes of HIV-1 (M, N, O, and P) likely arose through four separate transmissions of SIV to humans, and the resulting HIV-1 group M strain most ...
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Visna Virus
''Visna-maedi virus'' (also known as ''Visna virus'', ''Maedi-visna virus'' and ''Ovine lentivirus'') from the genus ''Lentivirus'' and subfamily ''Orthoretrovirinae'', is a retrovirus that causes encephalitis and chronic pneumonitis in sheep. It is known as visna when found in the brain, and maedi when infecting the lungs. Lifelong, persistent infections in sheep occur in the lungs, lymph nodes, spleen, joints, central nervous system, and mammary glands; The condition is sometimes known as ovine progressive pneumonia (OPP), particularly in the United States, or Montana sheep disease. White blood cells of the monocyte/macrophage lineage are the main target of the virus. Viral infection First described in 1954 by Bjorn Sigurdsson in Iceland, Maedi-visna virus was the first lentivirus to be isolated and characterized, accomplished in 1957 by Sigurdsson. ''Maedi'' ( Icelandic ' 'dyspnoea') and ''visna'' (Icelandic ' 'wasting' or 'shrinking' of the spinal cord) refer to endemic shee ...
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Innate Immune System
The innate, or nonspecific, immune system is one of the two main immunity strategies (the other being the adaptive immune system) in vertebrates. The innate immune system is an older evolutionary defense strategy, relatively speaking, and is the dominant immune system response found in plants, fungi, insects, and primitive multicellular organisms (see Beyond vertebrates).. The major functions of the innate immune system are to: * recruit immune cells to infection sites by producing chemical factors, including chemical mediators called cytokines * activate the complement cascade to identify bacteria, activate cells, and promote clearance of antibody complexes or dead cells * identify and remove foreign substances present in organs, tissues, blood and lymph, by specialized white blood cells * activate the adaptive immune system through antigen presentation * act as a physical and chemical barrier to infectious agents; via physical measures such as skin and chemical measures such a ...
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