Viruses diseases

Virus-forschung, /. virus research, -krankheit, /. virus disease, vise-. Vise-, see visk-, Visk-. 

Cooper OB, Brown TT, Dobs AS Opiate drug use a potential contributor to the endocrine and metabolic complications in human immunodeficiency virus disease. Clin Infect Dis 37(suppl 2) S132—S136, 2003... 

Melino S, Paci M (2007) Progress for dengue virus diseases. Towards the NS2B-NS3pro inhibition for a therapeutic-based approach. FEES J 274 2986-3002 Murphy RL, Brun S, Hicks C, Eron JJ, GuUck R, King M, White AC Jr, Benson C, Thompson M, Kessler HA, Hammer S, Bertz R, Hsu A, Japour A, Sun E (2001) ABT-378/ritonavir plus stavudine and lamivudine for the treatment of antiretroviral-naive adults with HIV-1 infection 48-week results. AIDS 15 E1-E9... 

Haemophilus influenzae owes its specific name to the fact that it was thought to be the causal organism of influenza (now known to be a virus disease) as it was often isolated in cases ofinfluenza. It is the main cause ofinfantile meningitis and conjunctivitis and is one of the most important causes of chronic bronchitis. 

The long incubation times of many human virus diseases indicate that they replicate slowly in host cells. In tissue culture systems it has been shown that most human viruses take from 4 to 24 hours to complete a single replication cycle, contrasting with the 30 or so minutes for many bacterial viruses. 

Prions are responsible for the so-ealled slow virus diseases, a distinet group of unusual neurologieal disorders. They are believed to be markedly resistant to inactivation by many ehemieal and physical agents but because they have not been purified, it is at present diffieult to state whether this is an intrinsic property of prions or whether it results fkm the proteetive effect of host tissue present. Certainly very high coneentrations of a bioeide aeting for long periods may be necessary to produee inactivation. 

The JPPA has its own research institute in Ibaraki prefecture and two experimental stations in Kochi and Miyazaki for conducting many types of research services to evaluate the performance of agrochemicals. The research institute and experimental stations have test fields, greenhouses and research laboratories with the capability for chemical analyses. The research institute also provides several services such as identification of virus diseases or other crop pests on plants. 

The prion diseases are a closely related group of neuro-degenerative conditions which affect both humans and animals. They have previously been described as the subacute spongiform encephalopathies, slow virus diseases and transmissible dementias, and include scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, and the human prion diseases, Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker disease (GSS), fatal familial insomnia (FFI) and kuru. Prion diseases are... 

Unvaccinated persons who have frequent contact with those at high risk. / Persons who may have an inadequate response to vaccination (e.g., advanced human immunodeficiency virus disease). 

Barr, M. et al., Effects of multiple acute morphine exposures on feline immunodeficiency virus disease progression, J. Infect. Dis., 182, 725, 2000. 

The use of systemic insecticides has also opened up the possibility of combating virus diseases by controlling disease-carrying insects (cf. p. 171). Contact insecticides are again less efficient here as the insects are usually in hidden positions. 

The limiting factor in tomato production in the tropics is more apt to be a virus disease than a fungus disease of the foliage. The control of virus disease by control of the insect vector has been investigated in Mexico on potatoes (leaf roll, purple top), tomatoes (several unidentified viruses, one of which perhaps is curly top), and corn (corn stunt). Virus control in this way has been variable but usually negligible. This lack of control perhaps is due to slow kill of the insect vector, or to the continuous entry of the vector into the field. 

Other insects are of local importance including various beetles, grubs, the lesser cornstalk borer, and several vectors of virus diseases. The latter might be controlled by systemic insecticides. 

Yield increases in small trials of 25 to 30% have been secured in Louisiana by soil treatment at planting time with a combined insecticide and fungicide. This combined treatment deserves further investigation and it may have promising results. Hot water treatment of seed pieces can eliminate two virus diseases. Germination is stimulated at the same time and the possibility of augmenting this with fungicides has shown promise. Hot insecticides have not been tried. 

Swollen Shoot. Losses due to swollen shoot, a virus disease discovered in 1937 in the Gold Coast and still restricted to West Africa, are staggering. 

The pest control situation in California and Florida is reviewed, with particular attention to mechanical developments and the introduction of new fungicides and insecticides, such as the insoluble coppers and parathion, and the outstanding unsolved problems such as control for nematodes which will not injure the plant and the need for a systemic material which will control virus diseases. Emphasis is on needed lines of investigation. Pest control problems in Central America, the Caribbean Islands, and South America are discussed, with special reference to lack of suitable equipment and material because of dollar exchange problems. 

The time-honored method of controlling insect-borne virus diseases is by breeding resistant varieties. This has been practical in annual crops, but is hopelessly slow in tree crops, where it may take 20 years or more to test a new variety. What is needed desperately is some sort of treatment which will control the virus, probably a systemic treatment, as the virus works within the plant cells. This is not a new idea and work has been done along this line by many workers. A sense of urgency is inevitable, however, when 500 to 600 acres of citrus can be wiped out completely in 3 to 5 years time, followed by an expensive replanting job and a wait of 5 to 6 years to get back into production. This is the outstanding problem at the present time and may need years to answer. 

Do everything you can to prevent disease, as it can spread rapidly. Virus diseases are very difficult to control and affected plants should be removed and composted as soon as you notice them. The risk of infection by some fungal diseases can be reduced by raising the pH of the soil with lime (seep.55). Crop rotation (see pp.230-233) also plays an important role in reducing the severity of other soilborne diseases and some pests. 

The use of antibiotics for the control of plant virus diseases( ) is of interest. Several antibiotics have been tested for inhibition of replication of viral nucleic acid and/or protein synthesis within the host cell. Chloramphenicol, cycloheximide, actinomycin D and others are the most used antibiotics and the disease caused by tobacco mosaic... 

It is often said that when a suspected virus disease may be controlled by antibiotics(Table 3), the cause of the diseases must be mycoplasma and never a virus. This arbitrary statement segregating viruses from mycoplasma has many times been held valid, but there remain several other instances where application of antibiotics to the host plant has reduced the pathogenesis of viruses to a considerable degree(69-70). 

Ptasad SM, Prasad N, Barnwal MK, Evaluation of insecticides against aphid vectots of virus diseases of French Bean, JPlant Protect Environ 3 87—90, 2006. 

Information on the significance of carbohydrate chains of interferon, the protective agent against a number of virus diseases, has been ob-... 

A search for antimetabolites, i.e. analogues of essential metabolites that might displace the latter in vital processes, was proposed as a rational approach to the discovery of antibacterial agents, but it has had little success other than the achievements in the folic acid field (Section 1.06.6). Substances that resemble the components of nucleic acids have, however, had considerable success in the chemotherapy of cancer and of some virus diseases and in the suppression of the immune response. They may act by becoming incorporated in false nucleic acids or by blocking the synthesis of nucleic acids, nucleotides, nucleosides or of the pyrimidine and purine bases cytosine (88), thymine (89 R = Me), adenine (90) and guanine (91 X = CH). The simplest antimetabolites are analogues of these bases. 

Most bacterial infections can be treated successfully with antibiotics, but the development of satisfactory antiviral agents has been slow. Yet we are susceptible to many dangerous virus diseases, and viruses also take a huge toll among domestic animals and plants.3 The first antiviral drug, 5-iodo-2 -deoxyuridine (idoxuridine), was introduced in 1962 and was used for 20 years by ophthalmologists to treat serious eye infections by the herpes simplex virus (HSV). 

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