Growth of secondary Echinococcus multilocularis in experimentally infected hosts

1974 ◽  
Vol 52 (5) ◽  
pp. 587-589 ◽  
Author(s):  
R. W. Baron ◽  
M. E. Rau ◽  
C. E. Tanner
Keyword(s):  
Echinococcus Multilocularis ◽  
Larval Growth ◽  
Cotton Rat ◽  
Sigmoid Curve ◽  
Cotton Rats ◽  
Thin Walled ◽  
Several Intervals

The growth of larval Echinococcus multilocularis in cotton rats, jirds, and A/J mice was measured. Single, thin-walled, acephalic cysts from cotton rat donors were inoculated intraperitoneally into the experimental hosts, and cyst weights were taken at several intervals after infection. It is shown that larval growth can be quantitatively described since it follows a sigmoid curve. Protoscoleces were produced within the cysts in all three hosts, although the time of appearance differed in each case.

Echinococcus multilocularis in the cotton rat. Asexual proliferation following the intraperitoneal inoculation of graded doses of protoscolices

1972 ◽  
Vol 50 (7) ◽  
pp. 941-946 ◽  
Author(s):  
M. E. Rau ◽  
C. E. Tanner
Keyword(s):  
Intermediate Host ◽  
Echinococcus Multilocularis ◽  
Sigmodon Hispidus ◽  
Cotton Rat ◽  
Cotton Rats ◽  
The Mean ◽  
Intraperitoneal Inoculation

One hundred and nine cotton rats (Sigmodon hispidus) were each inoculated intraperitoneally with one of seven graded doses of Echinococcus multilocularis protoscolices. As the size of the inoculating dose increased, corresponding gains in the mean total parasitic cyst weight, measured 60 days later, became progressively less pronounced until a plateau was reached which even massive inoculations failed to elevate significantly. Mean total cyst weights attained within 60 days of inoculation varied seasonally, probably reflecting changes in the susceptibility of the intermediate host. Thus, cotton rats incubating infections during September, October, or November bore significantly lighter parasite burdens than rats incubating infections between December and August. Furthermore, at least 10 times the number of protoscolices were required to consistently establish infections during the three autumn months than at any other time of the year. Corresponding variations in the total cyst weight could be induced experimentally by manipulating the host's photoperiod.

Echinococcus multilocularis in the cotton rat. The effect of preexisting subcutaneous cysts on the development of a subsequent intraperitoneal inoculum of protoscolices

1973 ◽  
Vol 51 (1) ◽  
pp. 55-59 ◽  
Author(s):  
M. E. Rau ◽  
C. E. Tanner
Keyword(s):  
Echinococcus Multilocularis ◽  
Total Weight ◽  
Small Vesicle ◽  
Cotton Rat ◽  
Cotton Rats

Cotton rats were inoculated subcutaneousîy with small cysts of Echinococcus multilocularis and challenged intraperitoneally with 100 protoscolices 40 days later. Subcutaneous cysts which attained weights of more than about 5 g effectively suppressed the establishment, growth, and transperitoneal dissemination of the challenging infection. Normal cotton rats, inoculated intraperitoneally with 100 protoscolices, characteristically developed massive cysts which weighed, on the average, 31 g and consisted of about 31 cyst clusters. In contrast, animals which already harbored large, subcutaneous cysts developed only very mild infections following intraperitoneal reinoculation. Such hosts supported never more than two small, intraperitoneal cysts with a mean total weight of less than 1 g. The intensity of this suppression was underscored by the fact that even a single protoscolex or a small vesicle of E. multilocularis inoculated intraperitoneally into normal cotton rats could give rise to 11 g of cyst material distributed among as many as 87 cyst clusters.

scholarly journals Evolution of protection after maternal immunization for respiratory syncytial virus in cotton rats

2021 ◽  
Author(s):  
Jorge C.G. Blanco ◽  
Lori McGinnes-Cullen ◽  
Arash Kamali ◽  
Fatoumata Sylla ◽  
Marina Boukhavalova ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibody ◽  
Wild Type ◽  
Cotton Rat ◽  
Before And After ◽  
Boost Immunization ◽  
Cotton Rats ◽  
Antibody Titers ◽  
Syncytial Virus ◽  
Efficient Transfer

Maternal anti-respiratory syncytial virus (RSV) antibodies acquired by the fetus through the placenta protect neonates from RSV disease through the first weeks of life.  In the cotton rat model of RSV infections, we previously reported that immunization of dams during pregnancy with virus-like particles assembled with mutation stabilized pre-fusion F protein as well as the wild type G protein resulted in robust protection of their offspring from RSV challenge (Blanco, et al Journal of Virology 93: e00914-19, https://doi.org/10.1128/JVI.00914-19).  Here we describe the durability of those protective responses in dams, the durability of protection in offspring, and the transfer of that protection to offspring of two consecutive pregnancies without a second boost immunization.  We report that four weeks after birth, offspring of the first pregnancy were significantly protected from RSV replication in both lungs and nasal tissues after RSV challenge, but protection was reduced in pups at 6 weeks after birth.   However, the overall protection of offspring of the second pregnancy was considerably reduced, even at four weeks of age.  This drop in protection occurred even though the levels of total anti-pre-F IgG and neutralizing antibody titers in dams remained at similar, high levels before and after the second pregnancy.  The results are consistent with an evolution of antibody properties in dams to populations less efficiently transferred to offspring or the less efficient transfer of antibodies in elderly dams.

scholarly journals Immune response of mice to Echinococcus multilocularis infection after therapy with amphotericin B colloidal dispersion

2007 ◽  
Vol 44 (2) ◽  
pp. 47-56 ◽  
Author(s):  
J. Porubcová ◽  
E. Dvorožňáková ◽  
Z. Ševčíková
Keyword(s):  
Immune Response ◽  
Amphotericin B ◽  
Echinococcus Multilocularis ◽  
Proliferative Response ◽  
Larval Growth ◽  
Colloidal Dispersion ◽  
Cell Subpopulation ◽  
Th2 Immune Response ◽  
Ifn Γ

AbstractThe effect of amphotericin B colloidal dispersion (ABCD) on selected immunological parameters and growth of the larval cysts in mice infected intraperitoneally with Echinococcus multilocularis protoscoleces was observed. ABCD was administered at a dose 10 mg/kg body weight twice a week from week 5 to 10 post infection (p.i.). The Echinococcus infection suppressed the proliferative response of splenic T lymphocytes to nonspecific mitogen concanavalin A throughout almost the whole course of the experiment and ABCD administration did not affect this inhibittion. The increase in the proliferative response of B lymphocytes to lipopolysaccharide was found in infected mice with ABCD treatment from week 6 to 10 p.i. ABCD induced a significant rise of the splenic CD4 T cell subpopulation in infected mice only on week 6 p.i. The CD8 T subpopulation was not influenced by the therapy. The level of serum Th1 cytokine IFN-γ in infected and ABCD treated mice was elevated only at week 8 p.i., while the level of serum Th2 cytokine IL-5 was not influenced by the therapy. The ABCD treatment inhibited the IFN-γ production by splenocytes in vitro from week 6 to 10 p.i. On the contrary, the IL-5 production in vitro was stimulated at weeks 8 and 12 p.i. None antiparasitic effect of ABCD on larval growth was determined.Results suggest that amphotericin B colloidal dispersion did not affect the inhibited Th1 immune response after parasite infection. On the contrary, ABCD advanced the Th2 immune response development, which allows the progressive growth of the parasite.

scholarly journals STUDIES ON PNEUMONIA VIRUS OF MICE (PVM)

1946 ◽  
Vol 83 (1) ◽  
pp. 43-64 ◽  
Author(s):  
Frank L. Horsfall ◽  
Edward C. Curnen
Keyword(s):  
Neutralizing Antibodies ◽  
Animal Species ◽  
Pulmonary Infection ◽  
Mammalian Species ◽  
Late Winter ◽  
Atypical Pneumonia ◽  
Specific Antibody Response ◽  
Cotton Rat ◽  
Cotton Rats ◽  
Circulating Antibodies

The results of neutralization tests with PVM and serum obtained from numerous animal species indicate that antibodies agaiust this virus were present in the blood of all mammalian species tested, as not in that of fowls, and that their incidence in various species was widely different. They indicate, also, that in certain species, particularly the cotton rat, there were marked seasonal variations in the incidence of such antibodies; in the late winter and spring the incidence was much higher than during the summer and fall seasons. Cotton rats and hamsters which did not possess neutralizing antibodies against PVM were susceptible to manifest pulmonary infection with this virus, irrespective of the effects of previous experiments upon them, whereas those which possessed such antibodies were immune. It is suggested that circulating antibodies against PVM were present as a result of preceding infection with a latent virus; either PVM or an agent closely related to it in antigenic composition. Appropriate non-specific stimuli, e.g. the intranasal injection of suspensions of normal chick embryos, induced the development of neutralizing antibodies against PVM with significantly greater frequency in each of three species than occurred in control animals. Materials derived from patients with primary atypical pneumonia yielded results almost identical to those obtained with normal chick embryo suspensions. It is suggested that such materials, like the other non-specific stimuli employed, were effective in evoking a specific antibody response, because they unbalanced an equilibrium which previously existed between animal host and latent pneumotropic virus.

OBSERVATIONS ON EXPERIMENTAL INFECTIONS WITH ECHINOCOCCUS IN RODENTS

1961 ◽  
Vol 39 (6) ◽  
pp. 877-891 ◽  
Author(s):  
Gloria A. Webster ◽  
T. W. M. Cameron
Keyword(s):  
Echinococcus Granulosus ◽  
Echinococcus Multilocularis ◽  
Early Stage ◽  
The Other ◽  
Host Reaction ◽  
Microscopic Anatomy ◽  
Larval Parasite ◽  
Experimental Infections ◽  
White Rats ◽  
Cotton Rats

Experimental infections in rodents with Echinococcus multilocularis sibiricensis, Echinococcus granulosus canadensis, and Echinococcus granulosus (Lebanon origin) both by ingestion of onchospheres and by parenteral injection are recorded. The microscopic anatomy of the larval parasite and of the host reaction are discussed and illustrated in detail. Voles and cotton rats display little resistance to the development of the cyst of E. m. sibiricensis and ultimately destroy the host, while collared lemmings and golden hamsters overcome the cyst and destroy it. Muskrats and certain white mice are intermediate in their effects. In all cases, however, some degree of degeneration of the parasite into the alveolar form is shown. White rats, guinea pigs, and rabbits could not be infected with this parasite. E. g. canadensis was developing in the lung of one AKR strain mouse while in the chinchilla the parasite commenced to develop in the lung but was overcome at an early stage. No development took place in the other species of hosts. E. granulosus (Lebanon) appeared to be developing successfully in some cotton rats and white mice fed on onchospheres.

scholarly journals Unique histological features of the tail skin of cotton rat (Sigmodon hispidus) related to caudal autotomy

Biology Open ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. bio058230
Author(s):  
Marina Hosotani ◽  
Teppei Nakamura ◽  
Osamu Ichii ◽  
Takao Irie ◽  
Yuji Sunden ◽  
...  
Keyword(s):  
Muscle Layer ◽  
Fracture Plane ◽  
Sigmodon Hispidus ◽  
Tail Regeneration ◽  
Cotton Rat ◽  
Histological Features ◽  
Laboratory Rats ◽  
Cotton Rats ◽  
Caudal Autotomy ◽  
Rat Tail

ABSTRACTCaudal autotomy in rodents is an evolutionarily acquired phenomenon enabling escape from predators, by discarding the tail skin after traumatic injuries. The histological mechanisms underlying caudal autotomy seem to differ among species. Cotton rats (Sigmodon hispidus), which are important laboratory rodents for human infectious diseases, possess a fragile tail. In this study, we compared the tail histology of cotton rats with that of laboratory rats (Rattus norvegicus), which have no fragility on their tail, to elucidate the process of rodent caudal autotomy. First, the cotton rats developed a false autotomy characterized by loss of the tail sheath with the caudal vertebrae remaining without tail regeneration. Second, we found the fracture plane was continuous from the interscale of the tail epidermis to the dermis, which was lined with an alignment of E-cadherin+ cells. Third, we found an obvious cleavage plane between the dermis and subjacent tissues of the cotton-rat tail, where the subcutis was composed of looser, finer, and fragmented collagen fibers compared with those of the rat. Additionally, the cotton-rat tail was easily torn, with minimum bleeding. The median coccygeal artery of the cotton rat had a thick smooth muscle layer, and its lumen was filled with the peeled intima with fibrin coagulation, which might be associated with reduced bleeding following caudal autotomy. Taken together, we reveal the unique histological features of the tail relating to the caudal autotomy process in the cotton rat, and provide novel insights to help clarify the rodent caudal autotomy mechanism.

scholarly journals The Cotton Rat Provides a Novel Model To Study Genital Herpes Infection and To Evaluate Preventive Strategies

2005 ◽  
Vol 79 (23) ◽  
pp. 14632-14639 ◽  
Author(s):  
Kevin C. Yim ◽  
Clifford J. Carroll ◽  
Ana Tuyama ◽  
Natalia Cheshenko ◽  
Maria Josefina Carlucci ◽  
...  
Keyword(s):  
Genital Herpes ◽  
Small Animal ◽  
Preventive Strategies ◽  
Cotton Rat ◽  
Sexually Transmitted ◽  
Vaginal Microbicide ◽  
Immunodeficiency Virus ◽  
Cotton Rats ◽  
Guinea Pig Model ◽  
Simplex Virus

ABSTRACT Prevention of genital herpes and other sexually transmitted infections (STI) is a critical health priority because of the overwhelming impact on women and infants and the epidemiological association with human immunodeficiency virus (HIV)/AIDS. Small animal models are essential for evaluating strategies for prevention or treatment of STI. Neither the murine nor the guinea pig model of genital herpes fully recapitulates human disease. We demonstrate that herpes simplex virus type 2 (HSV-2) readily infects inbred cotton rats (Sigmodon hispidus). Consistent infection does not require pretreatment with medroxyprogesterone, and primary disease resembles that observed in humans. The animals develop genital lesions and fully recover. During primary infection, viral DNA is also detected in liver, lungs, brain, and kidneys. Clinical self-limited recurrences occur spontaneously but may also be induced by dexamethasone. Pretreatment of cotton rats with PRO 2000 gel, a candidate vaginal microbicide being evaluated in clinical trials to prevent HSV and HIV, protects cotton rats from HSV. Together, these studies suggest that the cotton rat may provide an excellent model to study genital herpes and to evaluate preventive strategies.

scholarly journals Close pathological correlations between chronic kidney disease and reproductive organ-associated abnormalities in female cotton rats

2018 ◽  
Vol 243 (5) ◽  
pp. 418-427 ◽  
Author(s):  
Osamu Ichii ◽  
Teppei Nakamura ◽  
Takao Irie ◽  
Hirokazu Kouguchi ◽  
Kozue Sotozaki ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Renal Dysfunction ◽  
Reproductive Organ ◽  
Female Reproductive System ◽  
Related Factors ◽  
Elderly Individuals ◽  
Cotton Rat ◽  
Cotton Rats ◽  
Immunological Abnormalities

Cotton rat ( Sigmodon hispidus) is a useful experimental rodent for the study of human infectious diseases. We previously clarified that cotton rats, particularly females, developed chronic kidney disease characterized by cystic lesions, inflammation, and fibrosis. The present study investigated female-associated factors for chronic kidney disease development in cotton rats. Notably, female cotton rats developed separation of the pelvic symphysis and hypertrophy in the vaginal parts of the cervix with age, which strongly associated with pyometra. The development of pyometra closely associated with the deterioration of renal dysfunction or immunological abnormalities was indicated by blood urea nitrogen and serum creatinine or spleen weight and serum albumin/globulin ratio, respectively. These parameters for renal dysfunction and immunological abnormalities were statistically correlated. These phenotypes found in the female reproductive organs were completely inhibited by ovariectomy. Further, the female cotton rats with pyometra tended to show more severe chronic kidney disease phenotypes and immunological abnormalities than those without pyometra; these changes were inhibited in ovariectomized cotton rats. With regard to renal histopathology, cystic lesions, inflammation, and fibrosis were ameliorated by ovariectomy. Notably, the immunostaining intensity of estrogen receptor α and estrogen receptor β were weak in the healthy kidneys, but both estrogen receptors were strongly induced in the renal tubules showing cystic changes. In conclusion, the close correlations among female reproductive organ-associated abnormalities, immunological abnormalities, and renal dysfunction characterize the chronic kidney disease features of female cotton rats. Thus, the cotton rat is a unique rodent model to elucidate the pathological crosstalk between chronic kidney disease and sex-related factors. Impact statement The increasing number of elderly individuals in the overall population has led to a concomitant age-related increase in chronic kidney disease. Moreover, the global prevalence of patients with chronic kidney disease is gradually increasing, which poses a serious public health problem. The limited number of spontaneous chronic kidney disease animal models, which resemble chronic kidney disease pathogenesis in elderly individuals, is a major limitation in the development of experimental and curative medicines for chronic kidney disease. This pathological study clarified that sex-related factors, including hormones, and abnormalities of the female reproductive system, such as pyometra, are closely associated with chronic kidney disease development by using cotton rats ( Sigmodon hispidus). Further, ovariectomy inhibited the phenotypes of the female reproductive system, immunological abnormalities, and chronic kidney disease. Thus, this laboratory rodent serves as a novel and useful spontaneous chronic kidney disease model to elucidate the candidate disease factors and the pathogenesis of chronic kidney disease both in human and experimental medicine.

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