scholarly journals STUDIES ON THE ETIOLOGY AND TRANSMISSION OF EPIDEMIC DIARRHEA OF INFANT MICE

1957 ◽  
Vol 106 (5) ◽  
pp. 743-755 ◽  
Author(s):  
Lisbeth M. Kraft
Keyword(s):  
Incubation Period ◽  
Oral Route ◽  
Resistant Virus ◽  
Heat Resistant ◽  
Hyperimmune Antiserum ◽  
Time Of Feeding

Transmission experiments have shown that epidemic diarrhea of infant mice of the CFW strain is infectious and communicable. Cage to cage spread can take place by the air-borne route. The agent appears to be a fairly heat-resistant virus that can be serially transferred and that is neutralized by specific hyperimmune antiserum from rabbits. Mice are susceptible to it by the oral route from at least the 3rd day after birth to the 10th or 11th day. Thereafter they appear to become resistant. The shortest incubation period observed has been 40 hours from the time of feeding infectious material; the longest period could not be ascertained under the conditions of test. Factors relative to the differentiation of this virus from other viruses are briefly discussed.

scholarly journals Identification and Characterization of a Poliovirus Capsid Mutant with Enhanced Thermal Stability

2018 ◽  
Vol 93 (6) ◽  
Author(s):  
Y Nguyen ◽  
Palmy R. Jesudhasan ◽  
Elizabeth R. Aguilera ◽  
Julie K. Pfeiffer
Keyword(s):  
Thermal Stability ◽  
High Temperatures ◽  
Oral Route ◽  
Mutant Virus ◽  
Single Amino Acid ◽  
Bacterial Surface ◽  
Virus Particles ◽  
Heat Resistant ◽  
Viral Particles ◽  
Very High

ABSTRACTEnteric viruses, including poliovirus, are spread by the fecal-oral route. In order to persist and transmit to a new host, enteric virus particles must remain stable once they are in the environment. Environmental stressors such as heat and disinfectants can inactivate virus particles and prevent viral transmission. It has been previously demonstrated that bacteria or bacterial surface glycans can enhance poliovirus virion stability and limit inactivation from heat or bleach. While investigating the mechanisms underlying bacterially enhanced virion thermal stability, we identified and characterized a poliovirus (PV) mutant with increased resistance to heat inactivation. The M132V mutant harbors a single amino acid change in the VP1 capsid coding that is sufficient to confer heat resistance but not bleach resistance. Although the M132V virus was stable in the absence of bacteria or feces at most temperatures, M132V virus was stabilized by feces at very high temperatures. M132V PV had reduced specific infectivity and RNA uncoating compared with those of wild-type (WT) PV, but viral yields in HeLa cells were similar. In orally inoculated mice, M132V had a slight fitness cost since fecal titers were lower and 12.5% of fecal viruses reverted to the WT. Overall, this work sheds light on factors that influence virion stability and fitness.IMPORTANCEViruses spread by the fecal-oral route need to maintain viability in the environment to ensure transmission. Previous work indicated that bacteria and bacterial surface polysaccharides can stabilize viral particles and enhance transmission. To explore factors that influence viral particle stability, we isolated a mutant poliovirus that is heat resistant. This mutant virus does not require feces for stability at most temperatures but can be stabilized by feces at very high temperatures. Even though the mutant virus is heat resistant, it is susceptible to inactivation by treatment with bleach. This work provides insight into how viral particles maintain infectivity in the environment.

scholarly journals Experimental Evidence of a Heat-Resistant Gastro-Intestinal Irritant produced by Bacilli of the Salmonella Group

1933 ◽  
Vol 33 (2) ◽  
pp. 233-244 ◽  
Author(s):  
William G. Savage
Keyword(s):  
Experimental Evidence ◽  
Food Poisoning ◽  
Oral Route ◽  
Theoretical Interest ◽  
Heat Resistant

The Salmonella group contains the organisms which are mainly responsible for outbreaks of food poisoning and the possibility of the production by these strains of bodies which are toxic, or which act as gastro-intestinal irritants, when administered by the oral route, is of practical as well as theoretical interest. This is especially the case if it can be shown that these irritant substances are heat resistant.

scholarly journals Creutzfeldt-Jakob disease a case report, with special attention to the electroencephalogram in this disorder and to its possible relationships to kuru, scrapie and «mad cow disease»

1993 ◽  
Vol 51 (2) ◽  
pp. 258-266
Author(s):  
A.H. Chapman ◽  
Djalma Vieira e Silva
Keyword(s):  
Case Report ◽  
Incubation Period ◽  
Middle Age ◽  
Oral Route ◽  
Spongiform Encephalopathy ◽  
Intracerebral Injection ◽  
X Rays ◽  
Affected Animal ◽  
Jakob Disease ◽  
Mad Cow Disease

A case of Creutzfeldt-Jakob disease in a 58-year-old Brazillian cattle rancher and businessman is presented. The EEG was normal, which is consistent with the fact that it was made during the first half of his illness; in a later stage suppression of normal rhythms by slow moderate voltage waves would be expected. The resemblances of kuru, scrapie and "mad cow disease» to C-J disease are discussed. In each of these 4 illnesses the patient or affected animal (scrapie and «mad cow disease") (a) has a widespread spongiform encephalopathy and consequent dementia, myoclonic epilepsy and cerebellar and corticospinal symptoms, (b) Each illness is caused by a virus (or virus-like organism called a PrP or prion) which is unusually resistant to heat and entirely resistant to ultraviolet light and x-rays, (c) This causative agent can be transmitted to other mammals by intracerebral injection or, in the proved cases of 3 of them, by the oral route. Unresolved questions about C-J disease include the following: Are C-J disease, kuru, scrapie and "mad cow disease" essentially similar illnesses caused by the same virus or by subtle variants of it? What is the incubation period of C-J disease, and does its virus exist for long periods of time in some asymptomatic persons, some of whom may never become neurologically ill? How does this virus enter the bodies of most persons with C-J disease, and why does the clinical disease characteristically occur only in middle age?

scholarly journals Towards a hepatitis A vaccine. A review

1984 ◽  
Vol 93 (2) ◽  
pp. 269-276 ◽  
Author(s):  
B. N. Anderson ◽  
A. G. Coulepis ◽  
I. D. Gust
Keyword(s):  
Incubation Period ◽  
Day Care ◽  
Hepatitis A ◽  
Acute Inflammation ◽  
Oral Route ◽  
Abdominal Discomfort ◽  
Environmental Sanitation ◽  
Day Care Centres ◽  
General Community

Hepatitis A is an acute inflammation of the liver caused by a virus (HAV) whose morphology and physical characteristics resemble members of the enterovirus group. The disease, which is characterized by fever, malaise, anorexia, nausea, abdominal discomfort and jaundice has an average incubation period of 28–30 days and is spread from person to person by the faecal-oral route. Common-vehicle outbreaks have been reported following contamination of food or water and epidemics may occur in closed communities (institutions, day-care centres) or in the general community when there is a breakdown of environmental sanitation. Many infections, especially in children, are subclinical; the case fatility rate for patients requiring hospitalization is low and long-term sequelae are unknown.

scholarly journals Characterization of a thermal stable poliovirus mutant reveals distinct mechanisms of virion stabilization

2018 ◽  
Author(s):  
Y Nguyen ◽  
Palmy R. Jesudhasan ◽  
Elizabeth R. Aguilera ◽  
Julie K. Pfeiffer
Keyword(s):  
High Temperatures ◽  
Oral Route ◽  
Mutant Virus ◽  
Single Amino Acid ◽  
Wild Type Virus ◽  
Bacterial Surface ◽  
Virus Particles ◽  
Heat Resistant ◽  
Viral Particles ◽  
Very High

ABSTRACTEnteric viruses, including poliovirus, are spread by the fecal-oral route. In order to persist and transmit to a new host, enteric virus particles must remain stable once they are in the environment. Environmental stressors such as heat and disinfectants can inactivate virus particles and prevent viral transmission. It has been previously demonstrated that bacteria or bacterial surface glycans can enhance poliovirus virion stability and limit inactivation from heat or bleach. While investigating the mechanisms underlying bacterial-enhanced virion thermal stability, we identified and characterized a poliovirus mutant with increased resistance to heat inactivation. This poliovirus mutant, M132V, harbors a single amino acid change in the VP1 capsid-coding that is sufficient to confer heat resistance. M132V was comparable to wild-type virus for replicationin vitro, as well as for replication and pathogenesis in orally-inoculated mice. Although the M132V virus was stable in the absence of bacteria or feces at most temperatures, M132V virus was stabilized by feces at very high temperatures. Additionally, the M132V virus does not have enhanced stability during bleach treatment, suggesting that thermal and bleach inactivation mechanisms are separable. Our results suggest that different mechanisms underlie virion stabilization by bacteria and the M132V mutation. Overall, this work sheds light on factors that influence virion stability.IMPORTANCEViruses spread by the fecal-oral route need to maintain viability in the environment to ensure transmission. Previous work indicated that bacteria and bacterial surface polysaccharides can stabilize viral particles and enhance transmission. To explore factors that influence viral particle stability, we isolated a mutant poliovirus that is heat resistant. This mutant virus does not require feces for stability at most temperatures, but can be stabilized by feces at very high temperatures. Even though the mutant virus is heat resistant, it is susceptible to inactivation by treatment with bleach. This work provides insight into how viral particles maintain infectivity in the environment.

scholarly journals Autoclave treatment of the classical scrapie agent US No. 13-7 and experimental inoculation to susceptible VRQ/ARQ sheep via the oral route results in decreased transmission efficiency

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243009
Author(s):  
Eric D. Cassmann ◽  
Najiba Mammadova ◽  
Justin J. Greenlee
Keyword(s):  
Incubation Period ◽  
Brain Homogenate ◽  
Transmission Efficiency ◽  
Oral Route ◽  
Classical Scrapie ◽  
Time Interval ◽  
Post Inoculation ◽  
Autoclave Treatment ◽  
Scrapie Strain ◽  
Rectal Biopsies

Scrapie, a prion disease of sheep, is highly resistant to conventional deactivation. Numerous methods to deactivate scrapie have been tested in laboratory animal models, and adequate autoclave treatment can reduce or remove the infectivity of some classical scrapie strains depending on the heating parameters used. In this study, we autoclaved brain homogenate from a sheep with US scrapie strain 13–7 for 30 minutes at 121°C. Genetically susceptible VRQ/ARQ sheep were orally inoculated with 3 grams of the autoclaved brain homogenate. For comparison, a second group of sheep was inoculated with a non-autoclaved brain homogenate. Rectal biopsies were used to assess antemortem scrapie disease progression throughout the study. Five out of ten (5/10) sheep that received autoclaved inoculum ultimately developed scrapie after an experimental endpoint of 72 months. These sheep had a mean incubation period of 26.99 months. Two out of five (2/5) positive sheep had detectable PrPSc in antemortem rectal biopsies, and two (2/5) other sheep had PrPSc in postmortem rectal tissue. A single sheep (1/5) was positive for scrapie in the CNS, small intestine, and retropharyngeal lymph node but had negative rectal tissue. All of the sheep (10/10) that received non-autoclaved inoculum developed scrapie with a mean incubation period of 20.2 months and had positive rectal biopsies at the earliest timepoint (14.7 months post-inoculation). These results demonstrate that sheep are orally susceptible to US derived classical scrapie strain 13–7 after autoclave treatment at 121°C for 30 minutes. Differences in incubation periods and time interval to first positive rectal biopsies indicate a partial reduction in infectivity titers for the autoclaved inoculum group.

Effect of Temperature on ADP-Induced Platelet Aggregation

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Incubation Period ◽  
Room Temperature ◽  
Important Variable ◽  
Practical Significance ◽  
Effect Of Temperature ◽  
Induce Platelet Aggregation ◽  
Cuvette Holder ◽  
Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

Colchicine Uptake and Binding by Human Platelets

1975 ◽  
Vol 34 (03) ◽  
pp. 780-794 ◽  
Author(s):  
Dianne M Kenney ◽  
Francis C Chao ◽  
James L Tullis ◽  
Gail S Conneely
Keyword(s):  
Time Dependence ◽  
Incubation Period ◽  
Binding Sites ◽  
Silicone Oil ◽  
Cold Treatment ◽  
Human Platelets ◽  
Temperature Dependent

SummaryThe uptake and binding of antimitotic alkaloid colchicine has been demonstrated in washed preparations of human platelets. A silicone oil technique was adapted so that both uptake and binding of 14C-colchicine were examined in the same platelet preparations. The time dependence and amount of colchicine taken up and bound by different platelet preparations during a 90 to 120 min incubation period were highly reproducible. Both colchicine uptake and binding by intact platelets, and colchicine binding by preparations of lysed platelets were specific and temperature dependent. Colchicine uptake was slowly reversible. Magnesium and GTP enhanced colchicine binding by lysed platelet preparations but calcium decreased binding.Exposure of platelets to either cold (4° C) or to thrombin, which disrupt platelet microtubules, produced significant increases in colchicine uptake and binding. The thrombin effect was maximal at 37° C and resulted in a greater increase in uptake and binding than that produced by either cold treatment alone or, by cold treatment followed by incubation with thrombin at 37° C. The amount of increase in uptake and binding produced by thrombin was independent of both thrombin (1–5 Units/109 platelets) and colchicine concentrations (1–50 × 10−6M).It is postulated that thrombin may initiate the formation, or make available, colchicine binding sites (microtubule subunits) within platelets.

Effect of carbofuran on quantitative and qualitative alterations in haemolymph of larva of Oryctes rhinoceros L. (Coleoptera: Scarabaeidae)

ENTOMON ◽  
2020 ◽  
Vol 44 (4) ◽  
pp. 293-300
Author(s):  
V.S. Salini
Keyword(s):  
Oral Route ◽  
Toxicity Assessment ◽  
Haematological Parameters ◽  
Oryctes Rhinoceros ◽  
Total Haemocyte Count ◽  
Differential Haemocyte Count ◽  
Third Instar Larvae

Investigation to evaluate the toxicity of carbofuran pesticides on haematological parameters of third instar larvae of Oryctes rhinoceros L. Indicated alterations in total haemocyte count and differential haemocyte count for toxicity assessment. Various doses of carbofuran (0.05g, 0.010g and 0.015 g) applied on insect through oral route and its impact after 24 hours of its application revealed that various doses of carbofuran exert specific alterations in both total and differential haemocytes of insect haemolymph.

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