scholarly journals A RICKETTSIAL INFECTION IN CANADIAN VOLES

1946 ◽  
Vol 84 (1) ◽  
pp. 37-50 ◽  
Author(s):  
James A. Baker
Keyword(s):  
Guinea Pigs ◽  
Scrub Typhus ◽  
Living Cells ◽  
Rickettsial Infection ◽  
Contact Points ◽  
Inapparent Infection ◽  
On This Island ◽  
The Relationship ◽  
Lethal Doses ◽  
Infective Agent

From apparently normal voles captured on Grosse Isle, Province of Quebec, Canada, an infective agent has been grown in embryonated eggs, and by inoculation an inapparent infection was established in voles, mice, guinea pigs, hamsters, and rats. No growth of the agent was obtained in the absence of living cells, and the manner of its development in the yolk sac of embryonated eggs, as well as morphological, epidemiological, and pathogenic features, indicates a rickettsial nature. The inability to transmit infection by either cage or intrauterine contact points to a vector, and mites are shown to have a probable part in the epidemiology. Mice infected with the vole agent resist lethal doses of the Karp strain of scrub typhus, and certain epidemiological, morphological, and immunological features support the relationship indicated by the mouse tests. It is therefore concluded that voles on this island have an inapparent infection due to a rickettsia that may be related to the rickettsia of scrub typhus.

scholarly journals LEPTOSPIROSIS IN CATTLE

1948 ◽  
Vol 88 (3) ◽  
pp. 295-308 ◽  
Author(s):  
James A. Baker ◽  
Ralph B. Little
Keyword(s):  
Interstitial Nephritis ◽  
Guinea Pigs ◽  
Febrile Reaction ◽  
Milk Secretion ◽  
Experimental Animals ◽  
Comparative Tests ◽  
Immunological Properties ◽  
Lactating Cows ◽  
Inapparent Infection ◽  
Infective Agent

From abnormal milk of cows an agent has been transmitted to guinea pigs, rabbits, mice, and embryonated eggs. This agent caused a febrile reaction in guinea pigs and rabbits and an inapparent infection in mice. In early passages embryonated eggs were unaffected but later death of embryos occurred 7 days after inoculation. When blood from infected guinea pigs or chorioallantoic fluid from infected eggs was inoculated subcutaneously or intranasally into young calves, fever with albuminuria and more rarely hemoglobinuria was produced, in lactating cows the infection resembled that seen in animals with natural disease. Pen contact of normal cows and calves with infected calves resulted in inapparent infection. Autopsies showed that in addition to causing altered milk secretion, the agent damaged the kidneys and produced an interstitial nephritis. The agent was recovered from blood and milk during the febrile period and was demonstrated in the urine for periods long afterwards. Antibodies for the spirochete were found in the sera of experimental animals and of cows recovered from the natural disease. The blood of infected guinea pigs, the chorioallantoic fluid from infected eggs, and the blood or urine from experimentally infected calves yielded a culture of a spirochete which appeared identical with the infective agent in comparative tests of physical, pathogenic, and immunological properties.

Efficacy Comparison of Two Cholinolytics, Scopolamine and Azaprophen, When Used in Conjunction with Physostigmine and Pyridostigmine for Protection Against Organophosphate Exposure

1991 ◽  
Vol 10 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Richard P. Solana ◽  
Chris Gennings ◽  
Walter H. Carter ◽  
Dana Anderson ◽  
Willard J. Lennox ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Guinea Pigs ◽  
Therapeutic Efficacy ◽  
Nerve Agents ◽  
Behavioral Deficit ◽  
Rotarod Performance ◽  
The Relationship ◽  
Measured Response ◽  
Lethal Doses

Pretreatment with either pyridostigmine (PYR) or physostigmine (PHY) followed by atropineoxime therapy is very effective in reducing the lethality of organophosphorus nerve agents. The therapeutic efficacy of scopolamine (SCP) versus azaprophen (AZA), when used in conjunction with PHY and PYR (PHY/PYR) combination pretreatment, was evaluated in guinea pigs challenged with 2 half-lethal doses of soman. Maximum postsoman decrement of rotarod performance was measured. Response surface methodology was employed to describe the relationship between the decrement and the PHY/PYR dosages. Results show that AZA is a more effective pretreatment adjunct at the behavioral deficit-free doses tested, AZA or SCP is as effective with PHY alone as with a PHY/PYR combination. Thus, PYR adds essentially nothing to the carbamate combination against soman-induced behavioral deficit.

Immunology of the inner ear: Response of the inner ear to antigen challenge

1983 ◽  
Vol 91 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Jeffrey P. Harris
Keyword(s):  
Inner Ear ◽  
Blood Brain Barrier ◽  
Guinea Pigs ◽  
Keyhole Limpet Hemocyanin ◽  
Host Immunity ◽  
Brain Barrier ◽  
Antigen Challenge ◽  
Antibody Titers ◽  
Relationship Of ◽  
The Relationship

The relationship of the inner ear to host immunity and the immunoresponsiveness of the inner ear to antigen challenge were investigated. A radioimmunoassay was used to quantitate antibody titers to keyhole-limpet hemocyanin generated in the serum, perilymph, and CSF of guinea pigs following systemic or inner ear immunizations. The results of these experiments demonstrate (1) the blood-labyrinth barrier is analogous to the blood-brain barrier with respect to immunoglobulin equilibrium, (2) the inner ear is capable of responding to antigen challenge, and (3) the inner ear is an effective route for systemic immunization.

scholarly journals Efficacy of a Vaccine Based on Protective Antigen and Killed Spores against Experimental Inhalational Anthrax

2008 ◽  
Vol 77 (3) ◽  
pp. 1197-1207 ◽  
Author(s):  
Yves P. Gauthier ◽  
Jean-Nicolas Tournier ◽  
Jean-Charles Paucod ◽  
Jean-Philippe Corre ◽  
Michèle Mock ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Protective Immunity ◽  
Protective Antigen ◽  
Virulent Strain ◽  
Neutralizing Antibody ◽  
Cutaneous Anthrax ◽  
Anthrax Vaccines ◽  
Mucosal Secretions ◽  
Highly Virulent ◽  
Lethal Doses

ABSTRACTProtective antigen (PA)-based anthrax vaccines acting on toxins are less effective than live attenuated vaccines, suggesting that additional antigens may contribute to protective immunity. Several reports indicate that capsule or spore-associated antigens may enhance the protection afforded by PA. Addition of formaldehyde-inactivated spores (FIS) to PA (PA-FIS) elicits total protection against cutaneous anthrax. Nevertheless, vaccines that are effective against cutaneous anthrax may not be so against inhalational anthrax. The aim of this work was to optimize immunization with PA-FIS and to assess vaccine efficacy against inhalational anthrax. We assessed the immune response to recombinant anthrax PA fromBacillus anthracis(rPA)-FIS administered by various immunization protocols and the protection provided to mice and guinea pigs infected through the respiratory route with spores of a virulent strain ofB. anthracis. Combined subcutaneous plus intranasal immunization of mice yielded a mucosal immunoglobulin G response to rPA that was more than 20 times higher than that in lung mucosal secretions after subcutaneous vaccination. The titers of toxin-neutralizing antibody and antispore antibody were also significantly higher: nine and eight times higher, respectively. The optimized immunization elicited total protection of mice intranasally infected with the virulentB. anthracisstrain 17JB. Guinea pigs were fully protected, both against an intranasal challenge with 100 50% lethal doses (LD50) and against an aerosol with 75 LD50of spores of the highly virulent strain 9602. Conversely, immunization with PA alone did not elicit protection. These results demonstrate that the association of PA and spores is very much more effective than PA alone against experimental inhalational anthrax.

scholarly journals Splenic Infarction and Infectious Diseases in Korea

2020 ◽  
Author(s):  
Jae Hyoung Im ◽  
Moon-Hyun Chung ◽  
Hye-Jin Lee ◽  
Hea Yoon Kwon ◽  
JiHyeon Baek ◽  
...  
Keyword(s):  
Risk Factors ◽  
Immune Cells ◽  
Clinical Presentation ◽  
Scrub Typhus ◽  
Systemic Infection ◽  
Splenic Infarction ◽  
University Hospital ◽  
Radiological Findings ◽  
Epstein Barr ◽  
The Relationship

Abstract Background The spleen contains immune cells and exhibits a pattern of infarction different from other organs; as such, splenic infarction (SI) may provide important clues to infection. However, the nature of the relationship between SI and infectious disease(s) is not well understood. Accordingly, this retrospective study investigated the relationship between SI and infection. Methods Hospital records of patients with SI, who visited Inha University Hospital (Incheon, Republic of Korea) between January 2008 and December 2018, were reviewed. Patient data regarding clinical presentation, causative pathogens, risk factors, and radiological findings were collected and analyzed.Results Of 353 patients with SI, 101 with infectious conditions were enrolled in this study, and their data were analyzed to identify associations between SI and infection. Ten patients were diagnosed with infective endocarditis (IE), and 26 exhibited bacteremia without IE. Twenty-seven patients experienced systemic infection due to miscellaneous causes (negative result on conventional automated blood culture), including the following intracellular organisms: parasites (malaria [n =12], babesiosis [n =1]); bacteria (scrub typhus [n =5]); viruses (Epstein–Barr [n =1], cytomegalovirus [n =1]); and unidentified pathogen[s] (n =7). Splenomegaly was more common among patients with miscellaneous systemic infection; infarction involving other organs was rare. Thirty-eight patients had localized infections (e.g., respiratory, intra-abdominal, or skin and soft tissue infection), and most (35 of 38) had other risk factors for SI. Conclusions In this study, various infectious conditions were found to be associated with SI, and intracellular organisms were the most common causative pathogens. Further studies are needed to examine other possible etiologies and the underlying pathophysiological mechanisms.

Vascular pressure-volume relationships in pregnant and estrogen-treated guinea pigs

1989 ◽  
Vol 257 (5) ◽  
pp. R1205-R1211 ◽  
Author(s):  
L. E. Davis ◽  
A. R. Hohimer ◽  
G. D. Giraud ◽  
M. S. Paul ◽  
M. J. Morton
Keyword(s):  
Blood Volume ◽  
Guinea Pigs ◽  
Circulatory Arrest ◽  
Right Atrial ◽  
Blood Volume Expansion ◽  
Rapid Ventricular Pacing ◽  
The Difference ◽  
Unanesthetized Animals ◽  
The Relationship ◽  
Estrogen Administration

We investigated the relationship between mean circulatory filling pressure (MCFP) and blood volume in nonpregnant (NP), estrogen-treated (E), and pregnant (P) guinea pigs. Reversible circulatory arrest was produced by rapid ventricular pacing or acetylcholine in unanesthetized animals remote from surgery. MCFP (mmHg) was higher for E (7.1 +/- 0.3) than for NP (5.8 +/- 0.5) or P (5.3 +/- 0.4). The gradient for venous return, the difference between MCFP and right atrial pressure (mmHg), did not differ in NP- (6.0 +/- 0.5), P- (5.8 +/- 0.5), or E- (5.8 +/- 0.4) treated animals. Capacitance, the blood volume (ml/kg) at an MCFP of 6 mmHg, was increased in P (84 +/- 6) and E (89 +/- 7), compared with NP (64 +/- 5) animals. Compliance, the ratio of the change in volume to change in pressure in the range of 6-12 mmHg (ml.kg-1.mmHg-1), was greater in P (4.4 +/- 0.3) than NP (3.5 +/- 0.3) animals. Hexamethonium blockade did not affect MCFP, capacitance, or compliance. We conclude that the effect of blood volume expansion on the circulation in pregnancy cannot be predicted from knowledge of MCFP-blood volume relationships in the nonpregnant animal, because capacitance and compliance are altered. Estrogen administration to nonpregnant animals reproduces some of these effects.

Species differences in altitude tolerance following X-irradiation

1960 ◽  
Vol 198 (4) ◽  
pp. 762-764 ◽  
Author(s):  
Bernard D. Newsom ◽  
Donald J. Kimeldorf
Keyword(s):  
Food Consumption ◽  
Guinea Pigs ◽  
Species Differences ◽  
Lethal Dose ◽  
Tolerance Test ◽  
Simulated Altitude ◽  
Hypoxic Tolerance ◽  
X Irradiation ◽  
Altitude Tolerance ◽  
The Relationship

The relationship between altitude tolerance and food consumption was investigated in irradiated and nonirradiated animals of several species. Food consumption was measured for 3 days following a mid-lethal dose of x-irradiation to assess the degree of postirradiation anorexia. Seventy-two hours after irradiation those animals, as well as ad libitum-fed and food-deprived nonirradiated animals were exposed to a simulated altitude tolerance test. The mortality produced in 4 hours was used as the criterion of hypoxic tolerance for each species. Irradiated rabbits and rats exhibited a severe decrease in food consumption and an increased hypoxic tolerance. Food consumption of mice was depressed during the 3 days following irradiation although the effect was much less than that observed for rats and rabbits. Guinea pigs and hamsters exhibited only a slight decrease in food consumption with recovery occurring after 24 hours. Mice, guinea pigs and hamsters did not exhibit a significant increase in hypoxic tolerance 3 days after radiation exposure. When nonirradiated rabbits, rats, mice and guinea pigs were food deprived, the hypoxic tolerance was significantly increased in all species.

scholarly journals FATAL INFECTION OF IRRADIATED WHITE MICE WITH EUROPEAN TYPHUS BY THE INTRA-ABDOMINAL ROUTE

1941 ◽  
Vol 73 (5) ◽  
pp. 669-680
Author(s):  
P. Y. Liu ◽  
John C. Snyder ◽  
John F. Enders
Keyword(s):  
Guinea Pigs ◽  
Brain Lesions ◽  
Rickettsial Infection ◽  
X Ray ◽  
Fatal Infection ◽  
Adult Mice ◽  
Abdominal Route ◽  
Peritoneal Washings ◽  
Cross Immunity ◽  
Observation Period

A fatal infection of irradiated white mice with the Breinl strain of European typhus has been established and passed serially for 22 passages by the intra-abdominal route. Rickettsiae were abundant and easily demonstrable in the moribund or dead mice. The mortality of irradiated mice infected with passage material (peritoneal washings or blood) was nearly 100 per cent as contrasted to no mortality in the control mice given the same dose of x-ray (450 R) and the same volume of fluid intra-abdominally. (The observation period of control mice was arbitrarily limited to 14 days.) After eighteen passages in irradiated mice no increase in virulence for non-irradiated adult mice was detected. After passage in guinea pigs, the rickettsial infection deriving from the mouse passage material was identical with the Breinl strain as judged by fever, cross immunity tests, and brain lesions in sections.

scholarly journals Afibrinogenemia and Thrombocytopenia in Guinea Pigs Following Injection of Echis Colorata Venom

Blood ◽  
1962 ◽  
Vol 20 (6) ◽  
pp. 735-749 ◽  
Author(s):  
JADWIGA RECHNIC ◽  
POLA TRACHTENBERG ◽  
JULIAN CASPER ◽  
CHAJA MOROZ ◽  
ANDRÉ DE VRIES
Keyword(s):  
Guinea Pig ◽  
Intravenous Injection ◽  
Guinea Pigs ◽  
Procoagulant Activity ◽  
Rabbit Serum ◽  
Factor V ◽  
Factor V Deficiency ◽  
Fibrinogenolytic Activity ◽  
Fraction I ◽  
Lethal Doses

Abstract Intravenous injection into the guinea pig of lethal doses of Echis colorata venom or of each of its two chromatographic fractions, separately, caused hemorrhage, afibrinogenemia, factor V deficiency and thrombocytopenia. Sublethal venom doses caused afibrinogenemia, factor V deficiency and thrombocytopenia in the absence of hemorrhage. Early intravascular clotting was observed following injection of high lethal doses of both whole venom and of procoagulant-containing fraction II, but not of fraction I which was devoid of procoagulant activity. The afibrinogenemia produced by fraction I was due to its fibrinogenolysin, whereas the afibrinogenemia produced by fraction II, which also had fibrinogenolytic activity, was due chiefly to its procoagulant. Anti-Echis colorata venom rabbit serum inhibited the fibrinogenolytic, the procoagulant and the thrombocytopenic activities of the venom.

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