Edward Stuart Bessman, M.B.A., M.D.
 https://www.hopkinsmedicine.org/profiles/results/directory/profile/0012955/edward-bessman The replicating viruses then stimulate an immune response and thereby prevent the transport of virus into the blood and to the central nervous system impotence from priapism surgery buy generic dapoxetine 60mg line. Poliomyelitis virus infects only certain subsets of nerve cells and in the process of its multiplication damages or destroys these cells erectile dysfunction treatment photos effective 60mg dapoxetine. The large so called anterior horn cells of the spinal cord are the most promi nently involved erectile dysfunction dx code buy dapoxetine 60 mg online. Since these cells relay information that controls motor Poliomyelitis 181 functions of the arms and legs erectile dysfunction pump manufacturers discount dapoxetine 60 mg on line, it is not surprising that poliomyelitis virus infection becomes visible as weakness of the limbs preceding paralysis. In severe cases, other neurons are involved including those of the brain stem where breathing and swallowing are controlled. Usually, though, the neurons in the cortex, the area of the brain associated with learn ing, are spared so that intelligence and cognitive functions remain intact. In the most frightening form of polio, involvement of the lungs and throat is uncommon, and was so even during the worst epidemics. When it occurred, the only option was to place the patient in the infamous iron lung to force the exchange of air into and out of the lungs. If the paralyzed respiratory muscles recovered and the time in the iron lung was short, survival was possible. Experimentally, air was pumped in and out of a box in which a cat whose respiratory muscles were paralyzed was kept alive. The Drinker respira tor, or iron lung, was a rigid cylinder in which the patient was placed, and at regular intervals negative and positive pressure was applied within the chamber. But during a severe epidemic of poliomyelitis in Copenhagen in 1952, with an attack rate of 238 polio patients per 100,000 individuals, the number of patients who could not breathe or swallow far exceeded the iron lungs available. The approach was to apply the principles used in anesthesia, positive pres sure ventilation?pumping air into the paralyzed lungs through a tube inserted directly into the trachea?essentially adapting a technique of the surgical operating room to the polio ward. The subsequently designed mechanical positive pressure respirators eventually replaced the iron lung tanks. One, Dianne Odell of Jackson, Tennessee, who developed poliomyelitis at age three, has been in an iron lung for? The cost is $1,000/week and, outrageously, was disapproved for Medicare reimbursement. However, during even this relatively short time span, the virus can replicate and spread widely. Of those actually infected by the poliomyelitis virus, fewer than 1 to 2 percent become paralyzed. The most common aftermath (>98 percent of individuals so infected) is that the patient develops fever, weakness, drowsiness, headache, nausea, vomiting, constipation, or sore throat in various combinations. Alternatively, a much smaller number suffers troubling stiffness and pain in the back of the neck that lasts for two to ten days. For in fewer still (less than 1 percent), the disease advances to paralysis of the limbs and sometimes involves brain centers that control respiration. The knowledge that poliomyelitis viruses infected the alimentary tract and multiplied there before spreading into the nervous system overcame a major stumbling block in controlling the disease. Yet, two other barriers had to be removed before an effective vaccine was developed. Immunity to smallpox or yellow fever is dependent on protection against a single virus strain. But this realiza tion did not surface until the 1930s with the work of Macfarlane Burnet. The painstaking work of the Typing Committee set up by the National Foundation for Infantile Paralysis in the United States? This they accomplished by typing over 195 different poliomyelitis virus isolates collected from near and far. These tests were done primarily on monkeys because no one then had the ability to grow viruses in cultured cells. The seminal contribution of Enders, Weller, and Robbins was their development of an easily manipulatable tissue culture system in which poliomyelitis virus could be grown (31). Finding that they did not need to use nerve cells, which are hard to manipulate and keep alive in culture, but could substitute nonneuronal cells in which poliomyelitis viruses readily replicate, was the turning point in formulating their suc cessful culture system and led to their Nobel Prize in 1956. The idea was to purify the viruses grown in culture, then inactivate them with a chemical that would kill them, thus destroying their viru lence (ability to cause disease in a host) while retaining their antigenicity (the ability to generate an immune response). One objection was that the inacti vated virus would enter the body by needle into the skin and muscle, as opposed to the gut and alimentary tract. Because the virus normally enters its host through the mouth and digestive tract, providing live atten uated virus vaccine that mimics the usual site of infection would be better for achieving optimal immunity. Further, attenuated live viruses had been the most universally successful vaccines, as witnessed by their ability to protect against smallpox and yellow fever. An additional argu ment was that, although the chemically inactivated vaccine might lead to immunity, this immunity was limited in time so that booster vaccinations would be required. Others argued that an infectious viral particle might escape the killing procedure and cause acute infection. This argument echoed a chemical inactivation approach that had been tried earlier. Soon afterward, in 1936, over 3,000 children were inoculated with this chemically killed virus with tragic results: some of them developed par alytic polio (2). It was and is still not clear whether these incidents of polio resulted because no one knew at that time that the virus was subdivided into three strains or because the virus was not suf? After discovery of the separate strains of poliomyelitis virus, the test of chemical inactivation was pursued in the early 1950s by Jonas Salk at the University of Pittsburgh (2,4,32,33). He successfully prepared a vac cine containing all three strains of poliomyelitis that had been killed with formaldehyde. He organized and administered this study of 650,000 children, of whom 440,000 received the vaccine and 210,000 a placebo, all administered by needle inoculation. It was at this announcement that the church 184 Viruses, Plagues, and History bells pealed across the American landscape. Mulvaney related years later, So when this vaccine came out; people were over joyed. This was wonderful because instead of having thousands of cases every year, there were practically none. This vaccine caused polio in 204 polio recipients of whom 75 percent, 153, were paralyzed and 11 died. Leonard Scheele, Surgeon General of the United States, withdrew the Cutter vaccine from the market. Lastly, one child paralyzed as a result of the Cutter incident was Josephine Gottsdanker. Cutter), coupled with pressure released by media reporting, revolutionized popular and legal views of vaccine safety. In the period of 1946 to 1955 preceding vaccination, the incidence of poliomyelitis per year in the United States was 32,890 cases with 1,742 deaths. By contrast, after administration of the Salk vaccine, and before institution of the Sabin vaccine, the number of cases dropped to 5,749 with 268 deaths per year, although universal coverage for all suscep tible individuals had not been achieved. In Sweden, where only the inactivated vaccine was and is used up to the present, poliomyelitis was eliminated. Salk worked on a chemically killed vaccine; Sabin and Koprowski worked independently on developing a living attenuated vaccine. Photo of Albert Sabin courtesy of the National Library of Medicine; photo of Jonas Salk courtesy of the March of Dimes; Koprowski photo courtesy of Hilary Koprowski. Such attenuated viruses had been used for vaccination previously with dramatic effects. For example, Max Theiler isolated yellow fever virus and passed it through animals and tissue culture to develop the 17D strain of yellow fever vaccine, which was successful in the control of yellow fever. After Koprowski moved from Brazil to the United States to his job as Head of Research at Lederle Laboratories, he spent many hours dis cussing with Theiler the problem of immunization against poliomyelitis virus (6). From these discussions, he became convinced that the living attenuated vaccine would be the best choice. No side effects followed, and all those vaccinated made good antibody responses, proving their immunity. With the live attenuated viruses of all three types on hand, immunization trials were begun in 1956, with more than 1,000 children vaccinated orally (6). In 1956, Ghislain Courtois, director of a laboratory in Stanleyville, Belgian Congo, approached Koprowski about vaccinat ing chimpanzees in his chimpanzee camp. Later, when Courtois feared a poliomyelitis epidemic, he requested mass vaccination for local natives.
A stretched When bulk formers are used to treat diarrhea rectum can send messages to the spinal instead of constipation erectile dysfunction urinary tract infection order generic dapoxetine from india, they are taken with cord that further interrupt bladder func out any additional fuid erectile dysfunction and diabetic neuropathy effective dapoxetine 60mg. Diarrhea and ms in general erectile dysfunction statistics uk buy dapoxetine online pills, diarrhea is less of a problem see your doctor for people with ms than constipation erectile dysfunction 22 order dapoxetine with mastercard. Yet when it occurs, for whatever reasons, minor bowel symptoms may be treated it is often compounded by loss of control. After age 50, all people should have periodic The condition can be treated with prescrip examinations of the lower digestive system. Tese last two tests, in which the bowel is viewed directly For the person with ms, as with anyone with a fexible, lighted tube, are increasingly else, diarrhea might indicate a secondary routine as early diagnostic exams. Bowel Problems | 4 Good bowel habits it is much easier to prevent bowel problems by establishing good habits than to deal with impaction, incontinence, or dependency on laxatives later on. Drink enough fluids each day, drink two to three quarts of fuid (8?12 cups) whether you are thirsty or not. Put fiber into your diet Regular physical activity Fiber is plant material that holds water and is resistant to digestion. Ask your the stool moving by adding bulk and by doctor, nurse, or physical therapist. The best time of day to empty the bowel Getting enough fber in your daily diet is about a half hour after eating, when the may require more than eating fruits and emptying refex is strongest. Because ms can Stool softeners decrease sensation in the rectal area, you examples are colace? and surfak. But Benefber, Perdiem Fiber? (brown container), many people with mobility problems raise the Fibercon, citrucel?, or Fiberall. A footstool can create with one or two glasses of water, they help fll the same desired body angle, by raising your and moisturize the gastrointestinal tract. Avoid unnecessary stress Saline laxatives Your emotions afect your physical state, milk of magnesia, epsom salts, and sorbitol are including the functioning of your bowel. They are reasonably And remember that a successful bowel sched safe, but should not be taken on a long term ule often takes time to become established. The constipation can upset you further, starting an unnecessary cycle other laxatives include Doxidan, and of worsening conditions. Bowel Problems | 6 Suppositories impaction if oral laxatives fail, you may be told to try and incontinence a glycerin suppository half an hour before attempting a bowel movement. This practice impaction refers to a hard mass of stool may be necessary for several weeks in order that is lodged in the rectum and cannot be to establish a regular bowel routine. This problem requires immediate some people, suppositories are needed on a attention. Tese agents must want you to have a series of tests to rule out be carefully placed against the rectal wall the chance of the more serious diseases. The external Enemas sphincter, although under voluntary control, enemas should be used sparingly, but is frequently weakened by ms and may they may be recommended as part of a not be able to remain closed. Watery therapy that includes stool softeners, bulk stool behind the impaction thus leaks supplements, and mild oral laxatives. A bowel accident? may be the frst warning a person has that an Manual stimulation annoying problem has become a major issue. You can sometimes promote elimination by gently massaging the abdomen in a incontinence clockwise direction, or by inserting a fnger in the rectum and rotating it gently. Bowel Problems | 7 if incontinence is even an occasional in conclusion problem, see your doctor but don?t be discouraged. Dealing A regular schedule of elimination may be with impaction, incontinence, and potential the key. When the bowel becomes used to dependence on laxatives is much more emptying at specifc intervals, accidents are difcult than preventing the basic problems. Drugs such as tolterodine or Pro Banthine, often prescribed to quiet bladder spasms, can be helpful when a hyperactive bowel is the underlying cause of incontinence. You may have your post void residual urine volume? tested during this period to avoid possible urinary retention. An absorbent lining helps protect the skin, and a plastic outer lining contains odors and keeps clothing from becoming soiled. Bowel Problems | 8 For further reading * the National Multiple sclerosis society is proud to be a source of information about multiple The society publishes many other pamphlets sclerosis. Navigational Note: Disseminated intravascular Laboratory findings with no Laboratory findings and Life threatening Death coagulation bleeding bleeding consequences; urgent intervention indicated Definition: A disorder characterized by systemic pathological activation of blood clotting mechanisms which results in clot formation throughout the body. Navigational Note: Hemolysis Laboratory evidence of Evidence of hemolysis and Transfusion or medical Life threatening Death hemolysis only. Navigational Note: Leukocytosis >100,000/mm3 Clinical manifestations of Death leucostasis; urgent intervention indicated Definition: A disorder characterized by laboratory test results that indicate an increased number of white blood cells in the blood. Left ventricular systolic Symptomatic due to drop in Refractory or poorly Death dysfunction ejection fraction responsive controlled heart failure due to to intervention drop in ejection fraction; intervention such as ventricular assist device, intravenous vasopressor support, or heart transplant indicated Definition: A disorder characterized by failure of the left ventricle to produce adequate output. Navigational Note: Mobitz type I Asymptomatic, intervention Symptomatic; medical Symptomatic and Life threatening Death not indicated intervention indicated incompletely controlled consequences; urgent medically, or controlled with intervention indicated device. Navigational Note: Myocarditis Symptoms with moderate Severe with symptoms at rest Life threatening Death activity or exertion or with minimal activity or consequences; urgent exertion; intervention intervention indicated. Navigational Note: Pericardial effusion Asymptomatic effusion size Effusion with physiologic Life threatening Death small to moderate consequences consequences; urgent intervention indicated Definition: A disorder characterized by fluid collection within the pericardial sac, usually due to inflammation. Navigational Note: Pericardial tamponade Life threatening Death consequences; urgent intervention indicated Definition: A disorder characterized by an increase in intrapericardial pressure due to the collection of blood or fluid in the pericardium. Navigational Note: Pulmonary valve disease Asymptomatic valvular Asymptomatic; moderate Symptomatic; severe Life threatening Death thickening with or without regurgitation or stenosis by regurgitation or stenosis by consequences; urgent mild valvular regurgitation or imaging imaging; symptoms controlled intervention indicated. Navigational Note: Restrictive cardiomyopathy Imaging findings only Symptomatic without signs of Symptomatic heart failure or Refractory heart failure or Death heart failure other cardiac symptoms, other poorly controlled responsive to intervention; cardiac symptoms new onset of symptoms Definition: A disorder characterized by an inability of the ventricles to fill with blood because the myocardium (heart muscle) stiffens and loses its flexibility. Navigational Note: Sinus bradycardia Asymptomatic, intervention Symptomatic, intervention Symptomatic, intervention Life threatening Death not indicated not indicated; change in indicated consequences; urgent medication initiated intervention indicated Definition: A disorder characterized by a dysrhythmia with a heart rate less than 60 beats per minute that originates in the sinus node. Navigational Note: Sinus tachycardia Asymptomatic, intervention Symptomatic; non urgent Urgent medical intervention not indicated medical intervention indicated indicated Definition: A disorder characterized by a dysrhythmia with a heart rate greater than 100 beats per minute that originates in the sinus node. Navigational Note: Ventricular arrhythmia Asymptomatic, intervention Non urgent medical Urgent intervention indicated Life threatening Death not indicated intervention indicated consequences; hemodynamic compromise Definition: A disorder characterized by a dysrhythmia that originates in the ventricles. Navigational Note: Ventricular tachycardia Non urgent medical Symptomatic, urgent Life threatening Death intervention indicated intervention indicated consequences; hemodynamic compromise Definition: A disorder characterized by a dysrhythmia with a heart rate greater than 100 beats per minute that originates distal to the bundle of His. Navigational Note: Testosterone deficiency Asymptomatic; mild Replacement therapy symptoms with no initiated intervention indicated Definition: A disorder characterized by low testosterone. Navigational Note: Corneal ulcer Corneal ulcer without Perforation in the affected perforation in the affected eye eye Definition: A disorder characterized by an area of epithelial tissue loss on the surface of the cornea. Extraocular muscle paresis Asymptomatic; clinical or Unilateral paresis without Bilateral paresis or unilateral Bilateral paresis requiring diagnostic observations only double vision paresis causing double vision head turning to see beyond in peripheral gaze, but not in central 60 degrees or double central gaze vision in central gaze Definition: A disorder characterized by incomplete paralysis of an extraocular muscle. Navigational Note: Papilledema Asymptomatic; no visual field Symptomatic; moderate Symptomatic with marked Best corrected visual acuity of deficit decrease in visual acuity (best decrease in visual acuity (best 20/200 or worse in the corrected visual acuity 20/40 corrected visual acuity worse affected eye and better or 3 lines or less than 20/40 or more than 3 decreased vision from known lines of decreased vision from baseline) known baseline, up to 20/200) Definition: A disorder characterized by swelling around the optic disc. Navigational Note: Uveitis Anterior uveitis with trace Anterior uveitis with 1+ or 2+ Anterior uveitis with 3+ or Best corrected visual acuity of cells cells greater cells; intermediate 20/200 or worse in the posterior or pan uveitis affected eye Definition: A disorder characterized by inflammation to the uvea of the eye. Navigational Note: Watering eyes Intervention not indicated Symptomatic; moderate Marked decrease in visual Best corrected visual acuity of decrease in visual acuity (best acuity (best corrected visual 20/200 or worse in the corrected visual acuity 20/40 acuity worse than 20/40 or affected eye and better or 3 lines or less more than 3 lines of decreased vision from known decreased vision from known baseline) baseline, up to 20/200) Definition: A disorder characterized by excessive tearing in the eyes; it can be caused by overproduction of tears or impaired drainage of the tear duct. Navigational Note: Anal fistula Asymptomatic Symptomatic, invasive Invasive intervention Life threatening Death intervention not indicated indicated consequences; urgent intervention indicated Definition: A disorder characterized by an abnormal communication between the opening in the anal canal to the perianal skin. Navigational Note: Belching Increase from baseline Intervention initiated (including over the counter medications) Definition: To expel gas noisily from the mouth. Navigational Note: Synonym: Burping Bloating No change in bowel function Symptomatic, decreased oral or oral intake intake; change in bowel function Definition: A disorder characterized by subject reported feeling of uncomfortable fullness of the abdomen. Navigational Note: Cecal hemorrhage Mild symptoms; intervention Moderate symptoms; Transfusion indicated; Life threatening Death not indicated intervention indicated invasive intervention consequences; urgent indicated; hospitalization intervention indicated Definition: A disorder characterized by bleeding from the cecum. Navigational Note: Colonic hemorrhage Mild symptoms; intervention Moderate symptoms; Transfusion indicated; Life threatening Death not indicated intervention indicated invasive intervention consequences; urgent indicated; hospitalization intervention indicated Definition: A disorder characterized by bleeding from the colon. Navigational Note: Dental caries One or more dental caries, Dental caries involving the Dental caries resulting in not involving the root root pulpitis or periapical abscess or resulting in tooth loss Definition: A disorder characterized by the decay of a tooth, in which it becomes softened, discolored and/or porous. Navigational Note: Duodenal fistula Asymptomatic Symptomatic, invasive Invasive intervention Life threatening Death intervention not indicated indicated consequences; urgent intervention indicated Definition: A disorder characterized by an abnormal communication between the duodenum and another organ or anatomic site.
In addition to their unprecedented size and hairy appearance erectile dysfunction causes treatment cheapest dapoxetine, mimivirus particles are highly resistant to extreme conditions (pH erectile dysfunction treatment delhi cheap 30 mg dapoxetine otc, temperature erectile dysfunction drugs patents generic dapoxetine 90mg visa, reducing agents) or enzymatic treatments (proteases erectile dysfunction diet buy discount dapoxetine line, glycosidases). The resilience of the particles may be due to their distinctive peripheral fber layer thought to be made of a dense mesh of a complex (lipo) polysaccharide biopolymer akin to the outer coat of bacterial spores. In place of inverted terminal repeats, the mimivirus genome has an inverted repeat of a 617 bp segment approximately 22 kb from one end of its genome and near the other end. Pairing these regions can lead to a putative Q like form for the mimivirus genome, with a long (22,514 bp) and a short (259 bp) tail. The 2D gels revealed numerous isoforms, probably due to posttranslational modifcations such as glycosyla tion, acetylation and phosphorylation. The presence of a complete transcription machinery in mimivirus particles is reminiscent of poxviruses. The next largest functional group contains nine gene products associated with oxidative pathways. Protein/lipid modifcation enzymes are also well represented, including a phosphoesterase and a lipase, which are eventually used for digesting the cell (vacuole) membrane, two protein kinases and a protein phosphatase. However, this mem brane organization might also result from the tight folding of a single membrane. Once the infecting virion is located within a phagocytic vacuole, the particle stargate opens allowing fusion of at least one of the mimivirus lipid membranes with the vacuole membrane. This fusion directly delivers the core of the particle into the host cytoplasm where it serves as a seed to initiate the formation of a DaneshGroup. C excess profle is shown on the innermost circle, exhibiting a peak around position 380,000. Accordingly, the mimivirus genome encodes a number of proteins homologous to enzymes key to the synthesis of bacterial cell walls. Mimivirus replication entirely takes place in the cyto plasm of the host Acanthamoeba cell, through the successive expression of early (from 0 to 3 h post infection), intermediate (from 3 h to 6 h post infection) and late (after 6 h post infection) transcripts, each gene class representing approximately one third of the mimivirus genome. The virion factories develop from the core of individual uncoated virus particles (seeds). The earliest viral transcripts are detected as soon as 15 minutes post infection, most likely produced by the viral transcription machin ery within the uncoated particles. Late genes (after 6 h) include virion struc tural components, as well as most of the virally encoded transcription apparatus components. This expression pattern suggests that the early and intermediate mimivirus transcripts detected before the appearance of fully mature cytoplasmic virion factories are generated by the transcription apparatus associated with the virion core. Mimivirus particles (at least one thousand per infected cell) are con tinually produced for up to 12 h by the growing virion factories (up to 6 m in diameter) (Figure 4). Mature mimivirus particles increasingly fll the host cytoplasm and are progressively released from the dying cell. Figure 4: the distinctive giant mimivirus virion factory in full production (8 h post infection in Acanthamoeba castellanii). Mimivirus readily infects many Acanthamoeba strains, including its preferred laboratory host Acanthamoeba castellanii. Metagenomic surveys indicate that close relatives of the Mimiviridae family are prevalent in the sea, where they probably infect marine heterotrophic protists and regu late plankton populations. As expected from the size of its particle, mimivirus is internalized by various professional phagocytic cells, including human macrophages in vitro. However, the recent demonstration that mimivirus particles are rec ognized by the sera of patients infected by Francisella tularensis, casts serious doubt on previously published serological evidence for mimivirus infection of humans. Biological properties the presence of many proteins never seen in any other virus is one of the unique features of mimivi rus. The mimivirus genome also encodes sev eral sugar manipulating enzymes likely to be involved in the biosynthesis of the particle outer layer. A new type of satellite virus (called the Sputnik virophage) has been isolated in association with a new strain of mimivirus (called mamavirus). List of other related viruses which may be members of the genus Mimivirus but have not been approved as species Terravirus Courdovirus Moumouvirus Derivation of name Mimi: for mimicking microbe. Specifc recognition of the major capsid protein of Acanthamoeba polyphaga Mimivirus by sera of patients infected by Francisella tularensis. Genus Whispovirus Type species White spot syndrome virus Virion properties morpholoGy Virions are ovoid or ellipsoid to bacilliform in shape, have a regular symmetry, and measure 120? 150nm in diameter and 270?290 nm in length. Most notable is the thread or fagellum like exten sion (appendage) at one end of the virion. The virion consists of an inner, rod shaped nucleocapsid with a tight ftting capsid layer, an intermediate tegument layer and an outer lipid containing tril aminar envelope. The isolated nucleocapsid typically measures 65?70 nm in diameter and 300? 350nm in length. The composition of lipids is known for virions purifed from the crayfsh Procambarus clarkii. The number of imperfect palindromic repeats (250 bp in size) within an hr varies per isolate. Viral transcripts are often but not always polyadenylated and they are usually capped. The solid arrows indicate the positions and direction of transcription of corresponding genes. Genotypic variants exist that can be distinguished by restriction length polymorphism and on the basis of genomic sequence. In recent years, researchers have found that the virus infection can be DaneshGroup. An unusual property of the virus is the extremely wide host range despite a very low level of genetic polymorphism. Infection sometimes causes disease and sometimes not, depending upon factors as yet poorly under stood but related to species tolerance and environmental triggers. Shrimp and other crustaceans sus ceptible to disease from this virus show gross signs of lethargy, such as lack of appetite and slow movement, and often a reddish coloration of the whole body together with white spots? embedded within the exoskeleton. These spots are the result of calcifed deposits that range in size from a few millimeters to 1 or more centimeters in diameter. However, in some cases such as acute experimental infections resulting from injected viral preparations, there may be no gross signs of infection other than lethargy and lack of appetite. With an appropriate infection dose to allow suffcient time before mortality, animals susceptible to disease show large numbers of virions circulating in the hemolymph, but this may also occur for tolerant species that show no mortality. Thus, high viral loads per se do not cause disease or mortality for all susceptible species. Species demarcation criteria in the genus Only a single species within the genus has been identifed to date (White spot syndrome virus). It should be realized, however, that as the Nimaviridae is a newly recognized family, the species concept is sub ject to change after existing and new isolates have been studied in more detail. List of other related viruses which may be members of the genus Whispovirus but have not been approved as species None reported. Derivation of name Nima: Latin for thread?; referring to the thread or tail like polar extension (appendage) on the virus particle. Pathogenicity of a baculovirus infection causing White spot syndrome in cultured penaeid shrimp in Taiwan. Identifcation of the nucleocapsid, tegument, and envelope proteins of the shrimp white spot syndrome virus virion. Identifcation of two major virion protein genes of White spot syndrome virus of shrimp. During productive infection, transcription of the viral genome is divided into early and late stages. Translation of the late transcripts produces structural proteins that are involved in capsid assembly. Several of the viral proteins contain sequences, termed nuclear localization signals, which facilitate transport of the proteins to the host cell nucleus where virion maturation occurs. Replication of the viral genome is initiated bi directionally by specifc binding of the E1 and E2 proteins at a unique origin of replication. Antigenic properties the L1 protein contains type specifc domains, and the L2 protein contains group specifc epitopes (see section on species demarcation for descriptions of groups and types). The availability of papil lomavirus like particles, resulting from the expression of L1 or L1 and L2 in baculovirus, vaccinia virus or yeast systems, has permitted a detailed analysis of antigenic characteristics. Biological properties Papillomaviruses are highly host species specifc and tissue restricted. Infection appears to occur mainly via microlesions of proliferating basal layer cells. The picobirnavirus crystal structure provides functional insights into virion assembly and cell entry erectile dysfunction over the counter purchase 30 mg dapoxetine free shipping. Genomic characterisation of the large segment of a rabbit picobirnavirus and comparison with the atypical picobirnavirus of Cryptosporidium parvum erectile dysfunction remedies fruits buy dapoxetine online from canada. Metagenomic analyses of viruses in stool samples from children with acute faccid paralysis hcpcs code for erectile dysfunction pump quality 30 mg dapoxetine. The subfamily Spinareovirinae contains viruses that have relatively large spikes or turrets situated at the 12 icosahedral vertices of either the virus or core particle xylitol erectile dysfunction buy 90 mg dapoxetine fast delivery. The subfamily Sedoreovirinae includes viruses that do not have large surface projections on their virions or core particles, giving them an almost spherical or smooth? appearance. The terminology that has been used to describe reovirus particles with different numbers of capsid layers varies among the genera. The transcriptionally active core particle of the spiked viruses (subfamily Spinareovirinae) appears to contain only a single complete capsid layer (which has been interpreted as having T? In most cases, the core is sur rounded (in the complete virion) by an incomplete protein layer (with T? One exception is the cypoviruses, which have transcriptionally active but fully intact virions with only a single capsid shell that are equivalent to the core particles of viruses from other genera. However, virus particles of most cypoviruses are characteristically occluded (either singly or mul tiply) within the matrix of proteinaceous crystals called polyhedra. In contrast, virions of the non spiked viruses (subfamily Sedoreovirinae) have an inner protein layer, which may be relatively fragile, having structural similarities to the innermost shell of the spiked viruses (interpreted as having T? However, in transcriptionally active core particles, the subcore is surrounded and reinforced by a complete core surface layer, which has T? These double layered cores have no surface spikes and (in intact virions) are surrounded by Virus Taxonomy: Ninth Report of the International Committee on Taxonomy of Viruses DaneshGroup. Orbivirus: a 3D model from x ray crys tallography of the core particle of an isolate of bluetongue 1 virus. Orthoreovirus: a 3D model from x ray crys tallography studies of a core particle of an isolate of mammalian orthoreovirus 3. Fijivirus: an electron micrograph of a core particle of an isolate of maize rough dwarf virus. Coltivirus: an electron micro graph of a negatively stained double shelled particle of an isolate of Colorado tick fever virus. Oryzavirus: an electron micrograph of a negatively stained core particle of an isolate of rice ragged stunt virus. Mycoreovirus: an electron micrograph of a negatively stained core particle of mycoreovirus 1 (Rosallinia necatrix mycore ovirus 1). Seadornavirus: an electron micrograph of a negatively stained core particle of an isolate of Banna virus. The reconstructions and electron micrographs are not shown to exactly the same scale. The outer capsid morphologies of members of the different genera of the family Reoviridae are more variable and may appear smooth, or with surface projects, or may even be absent. In the smooth cored genera, the enzymatically active minor proteins of the virion are attached to the inner surface of the central space at the fve fold axes of symmetry. However, in the spiked genera, some of these enzymatic proteins form turrets on the surface of the core. However, in most cases, the envelope appears to be transient and is not usually considered to be part of the intact virion. Some of the minor proteins may also play a structurally signifcant role as components of the virion, together with at least three major capsid proteins. The virion structural proteins range in size from 15 to 155 kDa and constitute about 80?85% of the dry weight of virions. Depending on the genus, a myristyl residue may be covalently attached to one of the virion proteins. Coltiviruses, rotaviruses and orbiviruses have an intermedi ate in virus morphogenesis or release, which may have a lipid envelope that is subsequently lost or removed. However, this may help to explain why virus particles are in some cases associated with membrane fractions in infected cell lysates. The mode of entry of viruses into cells varies between genera but usually results in loss of outer capsid components. Transcriptionally active parti cles derived from the parental virions (cores, represented by single or double layered particles, from subfamily Spinareovirinae or Sedoreovirinae, respectively) are released into the cell cytoplasm DaneshGroup. Many cypoviruses also form polyhedra, which are large crystalline protein matrices that occlude virus par ticles (either singly or multiply) and which appear to be involved in transmission between individual insect hosts. The steps involved in virion morphogenesis and virus egress from cells vary according to genus. The only known examples of non enveloped viruses that induce cell?cell fusion and syncy tium formation in virus infected cells are members of the family Reoviridae. In the case of fusogenic orthoreoviruses, syncytium formation promotes a rapid lytic response and release of progeny virions. Antigenic properties the viruses that infect vertebrate hosts generally possess both serogroup (virus species) specifc antigens, and (within each species or serogroup) more variable serotype specifc antigens. The viruses that infect plants and insects only may show greater uniformity and less antigenic varia tion in their proteins, possibly due to the lack of neutralizing antibodies in the host and therefore the absence of antibody selective pressure on neutralization specifc antigens. No antigenic rela tionship has been found between the viruses in different genera. Biological properties the biological properties of the viruses vary according to genus. Some viruses replicate only in certain vertebrate species (orthoreoviruses and rotaviruses) and are transmitted between hosts by respiratory or fecal?oral routes. Other vertebrate viruses (orbiviruses, coltiviruses and seadornavi ruses) replicate in both arthropod vectors. Plant viruses (phytoreoviruses, fjiviruses and oryzaviruses) replicate in both plants and arthropod vectors (leafhoppers). Viruses that infect insects (cypoviruses) are transmitted by contact or fecal?oral routes. Genus and species demarcation criteria in the family the number of genome segments (usually 9, 10, 11 or 12) is in most cases characteristic of viruses within a single genus, although the genus Mycoreovirus currently contains viruses with both 11 and 12 genome segments. Host (and vector) range and disease symptoms are also important indicators that help to identify viruses from different genera. Capsid structure (number of capsid layers, the presence of spiked or unspiked cores, and the symmetry and structure of the outer capsid) can also be signifcant. The level of sequence divergence, particularly in the more conserved genome seg ments and proteins (for example as detected by comparisons of RdRp or inner capsid shell proteins and the segments from which they are translated) can be used to distinguish members of differ ent genera. However, the RdRp of Rotavirus B isolates shows a high level of amino acid sequence divergence from that of other rotaviruses (? The prime determinant for inclusion of virus isolates within a single virus species is their ability to exchange genetic information during co infection, by genome segment re assortment, thereby generating viable progeny virus strains. However, data providing direct evidence of segment re assortment between isolates are only available for viruses in a few genera. The following meth ods are therefore commonly used (preferably in combination) to examine levels of similarity between isolates and to predict their possible compatibility: DaneshGroup. Stringency conditions may be selected so that viruses within a species will show hybridization. Virus isolates within the same species will show a relatively uniform electropherotype. However, a major deletion/insertion event may sometimes result in two distinct electropherotypes within a single species, and similarities can exist between more closely related species. These are usually con served across all segments within a species although some closely related species can also have identical terminal sequences on at least some segments. Additional or more specifc criteria are provided in the section for each genus, where applicable. All mem bers of the genus have a well defned capsid structure, as observed by electron microscopy and neg ative staining, with 12 spikes or turrets situated on the surface of the core particle at the icosahedral vertices. Members of all of the fve species, except Mammalian orthoreovi rus, induce syncytium formation. Order dapoxetine 90 mg free shipping. 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