Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of various fixatives and detergents on the in vitro detection of the viral determinants which are expressed in swine testis cells infected with the transmissible gastroenteritis coronavirus (TGEV) was studied using a microwell immunoperoxidase technique. When compared with glutaraldehyde and formaldehyde, 0.1% paraformaldehyde was found to be the fixative of choice for the detection of these determinants on the membranes of infected cells. Among dehydrating fixatives, 80% acetone or a mixture of acetone and ethanol or of acetone, methanol and ethanol were found to be the best fixatives for the detection of these viral determinants which are expressed in infected cells. In the case of acetone, the temperature of fixation and its concentration in the fixative preparation were found to be important. The treatment of 0.05% glutaraldehyde-fixed, infected cells with 0.1% saponin or 0.1% paraformaldehyde-fixed, infected cells with 1%NP-40 led to satisfactory detection of viral determinants. Using Triton X-100 to render cells permeable, the quantities of N and M antigen detected in TGEV-infected cells prefixed with either 0.05% glutaraldehyde or 0.1% paraformaldehyde were equal to those of 80% acetone-fixed, TGEV-infected cells while the quantity of S antigen detected was diminished. The effect of other detergents such as zwittergent, empigen BB, Chaps and N-lauroylsarcosine on the detection of viral determinants was also studied.
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PMID:Effect of fixation on the detection of transmissible gastroenteritis coronavirus antigens by the fixed-cell immunoperoxidase technique. 132 93

When treated with formaldehyde, Tween 80, sodium oleate and Nonidet P-40, avian infectious bronchitis virus, porcine transmissible gastroenteritis virus, neonatal calf diarrhea coronavirus, porcine hemagglutinating encephalomyelitis virus as well as the human coronavirus show similar inner structures by negative staining. The first one is an inner membranous bag. This structure could be evaginated following treatments used and does not show the characteristic projections of coronaviruses. Subsequently, the inner fold could be separated from the outer membrane at the point of junction between these two membranes. Each virus does not react in the same way to the action of the different products. The transmissible gastroenteritis virus appears more sensitive to treatments than other viruses. On the other hand, the hemagglutinating encephalomyelitis virus is the most resistant. The variable sensitivities of these viruses are not related to the type of host-cells. Also, a second internal structure, which is more dense than the viral particle, encircles partially the aperture of the internal tongue-shaped structure and seems to emerge from the viral particle through the aperture of the inner bag.
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PMID:Inner structures of some coronaviruses. 626 23

Of a variety of disinfectants evaluated, only sodium hypochlorite and sodium hydroxide inactivated porcine parvovirus (PPV) after a 5-minute incubation period. After the same incubation time, pseudorabies and transmissible gastroenteritis viruses were inactivated by all of the disinfectants tested. When the incubation time was increased to 20 minutes, 2% glutaraldehyde and a double-strength concentration of a commercial formaldehyde preparation also inactivated PPV. Formaldehyde vapor and ultraviolet radiations inactivated PPV also, but relatively long exposure times were required.
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PMID:Laboratory evaluation of selected disinfectants as virucidal agents against porcine parvovirus, pseudorabies virus, and transmissible gastroenteritis virus. 626 67

An immunohistochemistry technique was developed using fixed tissues to study the presence and location of transmissible gastroenteritis virus (TGEV) antigens in situ. Experimentally infected gnotobiotic and conventional pigs as well as pigs with natural TGEV infection were examined. The staining technique was based on detection of the major structural protein of TGEV, the nucleocapsid, by using a pool of 3 monoclonal antibodies. Formalin and periodate-lysine-paraformaldehyde (PLP)-fixed intestinal tissues from a gnotobiotic pig inoculated with virulent TGEV were used to determine optimal antibody concentrations and incubation times. The intestinal tissues remained in their respective fixatives for 6 months, and serial sections were removed at sequential times and embedded in paraffin blocks. PLP and 10% neutral buffered formalin were acceptable fixatives and preserved TGEV nucleocapsid antigenicity for up to 6 months. Formalin, in comparison with PLP as a fixative, was better for preserving original tissue morphology and provided better antigen detection. Conventional crossbred pigs were inoculated with virulent TGEV, and animals were euthanized on various postexposure days. Intestinal tissues were positive for TGEV nucleocapsid antigens on postexposure days 2, 4, and 8. The immunohistochemistry technique detected TGEV antigen in stored paraffin-embedded tissues from 14 naturally infected pigs previously confirmed as positive for TGEV using a direct immunofluorescence assay on intestinal mucosal smears, whereas 9 naturally infected pigs confirmed negative for TGEV antigen by the same immunofluorescence assay showed no staining consistent with the presence of TGEV antigen. Immunohistochemistry provides a method to detect TGEV and possibly other closely related coronaviruses such as porcine respiratory coronavirus in situ. A diagnostic test using the same fixed tissues processed for histopathology provides veterinary practitioners an alternative to delivering live pigs or refrigerated fresh intestinal samples containing infectious virus to a diagnostic laboratory. Investigators can utilize this technique to retrospectively screen fixed tissues for TGEV antigen.
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PMID:Immunohistochemistry of transmissible gastroenteritis virus antigens in fixed paraffin-embedded tissues. 874 36

Cryptosporidium sp. causes self-limiting gastroenteritis in immunocompetent individuals and can produce a life-threatening chronic diarrhea in immunodeficient patients. In order to obtain populations of selectively infective oocysts for inoculation in biological experiments, we developed an operational protocol for the enrichment of viable oocysts from crude fecal material. Using either fresh or formaldehyde-fixed feces as sources of viable and nonviable oocysts, respectively, we fractionated the samples on parallel discontinuous sucrose gradients and evaluated oocyst viability at different banding densities by an in vitro excystation assay. The formaldehyde-inactivated fecal samples formed no bands after centrifugation and 91.66% of the oocysts became concentrated in the pellet. Fresh fecal samples formed three bands at densities 1.062, 1.092, and 1.121, in addition to a sediment. Here the viability of the gradient-sedimented oocysts was 92.3% overall, and of those in the second band 100%. Modifications in oocyst permeability thus seems to alter their sedimentation characteristics so that consequent distribution on sucrose gradients can be correlated with oocyst viability. Discontinuous sucrose density gradient sedimentation would thus constitute a simple and rapid mean to obtain viable oocysts for use in biological models both in vivo and in vitro.
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PMID:[Relationship between discontinuous sucrose gradient and viability of Cryptosporidium sp. oocysts]. 1061 81