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Sample records for guinea pig cavia

  1. Insulinoma in 2 guinea pigs (Cavia porcellus)

    PubMed Central

    2005-01-01

    Abstract This paper describes an insulinoma in 2 guinea pigs (Cavia porcellus). Both guinea pigs presented with neurologic signs and low blood glucose readings. The neurologic signs resolved with dextrose administration. Insulinoma was confirmed on postmortem examination. PMID:15943120

  2. Prevalence of fur mites (Chirodiscoides caviae) in pet guinea pigs (Cavia porcellus) in southern Italy.

    PubMed

    d'Ovidio, Dario; Santoro, Domenico

    2014-04-01

    Chirodiscoides caviae is the most common fur mite affecting guinea pigs; infestation is generally asymptomatic. No studies have been published on the prevalence of such mites in guinea pigs in southern Italy. We sought to evaluate the prevalence and the clinical signs of C. caviae infestation in guinea pigs in southern Italy. Clinical records of guinea pigs evaluated from August 2012 to July 2013 were retrospectively searched. In this retrospective matched case-control study, records of guinea pigs with evidence of C. caviae infestation were selected. The prevalence of C. caviae infestation was evaluated and exposure variables were assessed among guinea pigs with and without infestation using stepwise conditional logistic regression. Guinea pigs seen during the same time period, but without a diagnosis of C. caviae, were included as control animals. The prevalence of C. caviae was 32% (42 of 131); 66.6% of affected guinea pigs (28 of 42) originated from pet shops, whereas 28% (14 of 42) were privately owned. Thirty-one guinea pigs (73.8%) were asymptomatic, whereas 11 (26.1%) showed clinical signs (pruritus, alopecia, erythema and scaling). The most frequently affected area was the lumbosacral region (38 of 42). Guinea pigs in pet shops were more likely to be affected by C. caviae than owned guinea pigs (odds ratio, 5.12; 95% confidence interval, 2.32-11.29; P < 0.0001). The results of this study indicate a high prevalence of C. caviae infestation in guinea pigs in southern Italy. Chirodiscoides mites should be sought in guinea pigs, particularly in animals coming from pet shops. © 2014 ESVD and ACVD.

  3. Prolactin Family of the Guinea Pig, Cavia porcellus

    PubMed Central

    Alam, S. M. Khorshed; Konno, Toshihiro; Rumi, M. A. Karim; Dong, Yafeng; Weiner, Carl P.; Soares, Michael J.

    2010-01-01

    Prolactin (PRL) is a multifunctional hormone with prominent roles in regulating growth and reproduction. The guinea pig (Cavia porcellus) has been extensively used in endocrine and reproduction research. Thus far, the PRL cDNA and protein have not been isolated from the guinea pig. In the present study, we used information derived from the public guinea pig genome database as a tool for identifying guinea pig PRL and PRL-related proteins. Guinea pig PRL exhibits prominent nucleotide and amino acid sequence differences when compared with PRLs of other eutherian mammals. In contrast, guinea pig GH is highly conserved. Expression of PRL and GH in the guinea pig is prominent in the anterior pituitary, similar to known expression patterns of PRL and GH for other species. Two additional guinea pig cDNAs were identified and termed PRL-related proteins (PRLRP1, PRLRP2). They exhibited a more distant relationship to PRL and their expression was restricted to the placenta. Recombinant guinea pig PRL protein was generated and shown to be biologically active in the PRL-responsive Nb2 lymphoma cell bioassay. In contrast, recombinant guinea pig PRLRP1 protein did not exhibit PRL-like bioactivity. In summary, we have developed a new set of research tools for investigating the biology of the PRL family in an important animal model, the guinea pig. PMID:20534723

  4. Efficacy of doramectin in Trixacarus caviae infestation in guinea pigs (Cavia porcellus).

    PubMed

    Singh, Shanker K; Dimri, Umesh; Ahmed, Quazi Shahir; Sayedda, Kauser; Singh, Krishna Veer

    2013-04-01

    The present study was intended to evaluate the efficacy of doramectin against seven naturally Trixacarus caviae infested male guinea pigs. Multiple skin scrapings of all the seven guinea pigs were found microscopically positive for T. caviae mites. Clinically these animals revealed, more or less denuded, very red often thickened, and crustated cutaneous lesions restricted at the sacral region and back. Doramectin 1 % (w/v) was administered intramuscularly at a dose rate of 400 μg/kg once weekly, which resulted in profound improvements in clinical conditions within 14 days after the first doramectin application. It took almost 28 days for the cutaneous lesions to disappear and to witness partial hair coat regrowth. Two moderately infested guinea pigs required only single injection of doramectin to achieve complete parasitological cure, while remaining five (one moderately infested and four severely infested) guinea pigs required two injections of doramectin to achieve complete parasitological cure. No adverse effects were revealed by any of the doramectin treated guinea pigs during the study period. Thus, it can be concluded from the present study that guinea pigs naturally infested by T. caviae mites can be cured safely using two doses of doramectin once in a week.

  5. Chlamydia caviae infection alters abundance but not composition of the guinea pig vaginal microbiota.

    PubMed

    Neuendorf, Elizabeth; Gajer, Pawel; Bowlin, Anne K; Marques, Patricia X; Ma, Bing; Yang, Hongqiu; Fu, Li; Humphrys, Michael S; Forney, Larry J; Myers, Garry S A; Bavoil, Patrik M; Rank, Roger G; Ravel, Jacques

    2015-06-01

    In humans, the vaginal microbiota is thought to be the first line of defense again pathogens including Chlamydia trachomatis. The guinea pig has been extensively used as a model to study chlamydial infection because it shares anatomical and physiological similarities with humans, such as a squamous vaginal epithelium as well as some of the long-term outcomes caused by chlamydial infection. In this study, we aimed to evaluate the guinea pig-C. caviae model of genital infection as a surrogate for studying the role of the vaginal microbiota in the early steps of C. trachomatis infection in humans. We used culture-independent molecular methods to characterize the relative and absolute abundance of bacterial phylotypes in the guinea pig vaginal microbiota in animals non-infected, mock-infected or infected by C. caviae. We showed that the guinea pig and human vaginal microbiotas are of different bacterial composition and abundance. Chlamydia caviae infection had a profound effect on the absolute abundance of bacterial phylotypes but not on the composition of the guinea pig vaginal microbiota. Our findings compromise the validity of the guinea pig-C. caviae model to study the role of the vaginal microbiota during the early steps of sexually transmitted infection. © FEMS 2015.

  6. Chlamydia caviae infection alters abundance but not composition of the guinea pig vaginal microbiota

    PubMed Central

    Neuendorf, Elizabeth; Gajer, Pawel; Bowlin, Anne K.; Marques, Patricia X.; Ma, Bing; Yang, Hongqiu; Fu, Li; Humphrys, Michael S.; Forney, Larry J.; Myers, Garry S.A.; Bavoil, Patrik M.; Rank, Roger G.; Ravel, Jacques

    2015-01-01

    In humans, the vaginal microbiota is thought to be the first line of defense again pathogens including Chlamydia trachomatis. The guinea pig has been extensively used as a model to study chlamydial infection because it shares anatomical and physiological similarities with humans, such as a squamous vaginal epithelium as well as some of the long-term outcomes caused by chlamydial infection. In this study, we aimed to evaluate the guinea pig-C. caviae model of genital infection as a surrogate for studying the role of the vaginal microbiota in the early steps of C. trachomatis infection in humans. We used culture-independent molecular methods to characterize the relative and absolute abundance of bacterial phylotypes in the guinea pig vaginal microbiota in animals non-infected, mock-infected or infected by C. caviae. We showed that the guinea pig and human vaginal microbiotas are of different bacterial composition and abundance. Chlamydia caviae infection had a profound effect on the absolute abundance of bacterial phylotypes but not on the composition of the guinea pig vaginal microbiota. Our findings compromise the validity of the guinea pig-C. caviae model to study the role of the vaginal microbiota during the early steps of sexually transmitted infection. PMID:25761873

  7. Similarities and differences among the chromosomes of the wild guinea pig Cavia tschudii and the domestic guinea pig Cavia porcellus (Rodentia, Caviidae)

    PubMed Central

    Walker, Laura I.; Soto, Miguel A.; Spotorno, Ángel E.

    2014-01-01

    Abstract Cavia tschudii Fitzinger, 1867 is a wild guinea pig species living in South America that according to the analysis of mitochondrial genes is the closest wild form of the domestic guinea pig. To investigate the genetic divergence between the wild and domestic species of guinea pigs from a cytogenetic perspective, we characterized and compared the C, G and AgNOR banded karyotypes of molecularly identified Cavia tschudii and Cavia porcellus Linnaeus, 1758 specimens for the first time. Both species showed 64 chromosomes of similar morphology, although C. tschudii had four medium size submetacentric pairs that were not observed in the C. porcellus karyotype. Differences in the C bands size and the mean number of AgNOR bands between the karyotypes of the two species were detected. Most of the two species chromosomes showed total G band correspondence, suggesting that they probably represent large syntenic blocks conserved over time. Partial G band correspondence detected among the four submetacentric chromosomes present only in the C. tschudii karyotype and their subtelocentric homologues in C. porcellus may be explained by the occurrence of four pericentric inversions that probably emerged and were fixed in the C. tschudii populations under domestication. The role of the chromosomal and genomic differences in the divergence of these two Cavia species is discussed. PMID:25147626

  8. Unilateral flank ovariohysterectomy in guinea pigs (Cavia porcellus).

    PubMed

    Rozanska, D; Rozanski, P; Orzelski, M; Chlebicka, N; Putowska, K

    2016-11-01

    To describe a simple, minimally invasive method of ovariohysterectomy via a unilateral flank approach in guinea pigs, for use in routine desexing of healthy female guinea pigs or treatment of ovarian cysts. The subjects of this retrospective study were 41 client-owned guinea pigs submitted for routine desexing or treatment of ovarian cysts. They included 16 healthy female guinea pigs aged 8-12 months (Group 1), and 15 females aged from 9 months to 3 years (Group 2), and 10 females aged from 3 to 7 years (Group 3) with different-sized ovarian cysts. Prior to surgery, the animals received clinical examination, blood testing (complete blood count and serum biochemistry profile) and examination of the abdomen using ultrasonography, to assess the condition of the reproductive tract and ensure the guinea pigs were fit for surgery. Ovariohysterectomy was performed via a unilateral flank incision made close to the erector spinae muscle starting approximately 1 cm caudal to the last rib. Both ovaries, uterine horns, and the uterine cervix were localised, ligated, and dissected through this unilateral retroperitoneal incision. Ovariohysterectomy was successfully completed via a single flank incision in 38/41 (93%) guinea pigs. Three guinea pigs with ovarian cysts from Group 3, which were >6 years old died during surgery due to circulatory and respiratory failure under anaesthesia. In the remaining 38 cases, surgery proceeded without complications. A further two guinea pigs from Group 3 were reluctant to move or eat for the first 3 days after surgery but recovered after provision of supportive care. All 38 animals fully recovered and wound healing was normal. This is the first report of ovariohysterectomy via a unilateral flank incision in guinea pigs. This approach is a simple, minimally invasive and safe alternative to the midline or bilateral flank approaches currently used for surgery of the reproductive tract in guinea pigs.

  9. Blood profiles in unanesthetized and anesthetized guinea pigs (Cavia porcellus).

    PubMed

    Williams, Wendy R; Johnston, Matthew S; Higgins, Sarah; Izzo, Angelo A; Kendall, Lon V

    2016-01-01

    The guinea pig is a common animal model that is used in biomedical research to study a variety of systems, including hormonal and immunological responses, pulmonary physiology, corticosteroid response and others. However, because guinea pigs are evolutionarily a prey species, they do not readily show behavioral signs of disease, which can make it difficult to detect illness in a laboratory setting. Minimally invasive blood tests, such as complete blood counts and plasma biochemistry assays, are useful in both human and veterinary medicine as an initial diagnostic technique to rule in or rule out systemic illness. In guinea pigs, phlebotomy for such tests often requires that the animals be anesthetized first. The authors evaluated hematological and plasma biochemical effects of two anesthetic agents that are commonly used with guinea pigs in a research setting: isoflurane and a combination of ketamine and xylazine. Hematological and plasma biochemical parameters were significantly different when guinea pigs were under either anesthetic, compared to when they were unanesthetized. Plasma proteins, liver enzymes, white blood cells and red blood cells appeared to be significantly altered by both anesthetics, and hematological and plasma biochemical differences were greater when guinea pigs were anesthetized with the combination of ketamine and xylazine than when they were anesthetized with isoflurane. Overall these results indicate that both anesthetics can significantly influence hematological and plasma biochemical parameters in guinea pigs.

  10. [Occurrence and distribution of ectoparasites in guinea pigs (Cavia spp.) in Peru, South America].

    PubMed

    de la Cruz, Katharina Dittmar; Ribbeck, Regine; Daugschies, Arwio

    2003-01-01

    Studies on the prevalence and distribution of ectoparasites in Peru were carried out during a period of 2 1/2 years. The survey included 17,421 domesticated guinea pigs (Cavia aperea f. porcellus) from 14 departments in all bioregions and altitude levels and 143 wild guinea pigs (Cavia aperea) from three areas (El Paramo, Junin and La Raya) in the Andes and the Cordillera. The guinea pig is an important source of food, especially for the rural population, the infestation with ectoparasites, such as fleas, lice or mites greatly contributes to a decrease in production and low performance. Ectoparasites can be vectors for a variety of pathogens, which is particularly problematic due to the close association of this animal with humans. Twenty one ectoparasite species have been recovered. New knowledge about host associations and distributions could be obtained. The results of the studies are presented under faunistic and ecological aspects.

  11. Streptococcus caviae sp. nov., isolated from guinea pig faecal samples.

    PubMed

    Palakawong Na Ayudthaya, Susakul; Hilderink, Loes J; Oost, John van der; Vos, Willem M de; Plugge, Caroline M

    2017-05-01

    A novel cellobiose-degrading and lactate-producing bacterium, strain Cavy grass 6T, was isolated from faecal samples of guinea pigs (Cavia porcellus). Cells of the strain were ovalshaped, non-motile, non-spore-forming, Gram-stain-positive and facultatively anaerobic. The strain gr at 25-40 °C (optimum 37 °C) and pH 4.5-9.5 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cavy grass 6T belongs to the genus Streptococcus with its closest relative being Streptococcus devriesei CCUG 47155T with only 96.5 % similarity. Comparing strain Cavy grass 6T and Streptococcus devriesei CCUG 47155T, average nucleotide identity and level of digital DNA-DNA hybridization dDDH were only 86.9 and 33.3 %, respectively. Housekeeping genes groEL and gyrA were different between strain Cavy grass 6T and other streptococci. The G+C content of strain Cavy grass 6T was 42.6±0.3 mol%. The major (>10 %) cellular fatty acids of strain Cavy grass 6T were C16:0, C20 : 1ω9c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Strain Cavy grass 6T ferment a range of plant mono- and disaccharides as well as polymeric carbohydrates, including cellobiose, dulcitol, d-glucose, maltose, raffinose, sucrose, l-sorbose, trehalose, inulin and dried grass extract, to lactate, formate, acetate and ethanol. Based on phylogenetic and physiological characteristics, Cavy grass 6T can be distinguished from other members of the genus Streptococcus. Therefore, a novel species of the genus Streptococcus, family Streptococcaceae, order Lactobacillales is proposed, Streptococcuscaviae sp. nov. (type strain Cavy grass 6T=TISTR 2371T=DSM 102819T).

  12. [Renal pleomorphic sarcoma in four guinea pigs (Cavia porcellus)].

    PubMed

    Hankel, Julia; Hewicker-Trautwein, Marion; Warschau, Martina; Thöle, Anna Milena; Fehr, Michael

    2017-09-20

    Renal tumours apparently are rare not only in cats and dogs, but also in guinea pigs and can be difficult to diagnose. The aim of this study is to describe the clinical, pathological and immunohistochemical findings in guinea pigs with renal tumours. Furthermore, the symptoms, diagnostic possibilities and therapy are compared with renal tumours in other small animals, including cats and dogs. During a period of 4 years and 4 months the data of guinea pigs that had been presented in the clinic were retrospectively analysed. The analysis comprised guinea pigs that underwent a macroscopical and histopathological postmortem examination, and were diagnosed to have a renal neoplasm. Four guinea pigs had a renal tumour. The percentage of renal neoplasms in relation to the overall necropsied carcasses and the number of organs originating from guinea pigs was 4.7 % and the percentage of renal neoplasms in relation to the overall diagnosed tumours of the abdominal and pelvic cavities was 30.7 %. Histology and immunohistochemistry revealed the presence of renal pleomorphic sarcomas in all four cases. In two of the four guinea pigs, the classical triad, as described for cats and dogs with renal tumours (weight loss, abdominal mass and haematuria), was observed. During clinical examination a prominent, apparently painful abdominal mass in the region of the kidneys was palpable in all four cases. Applying radiography the suspected diagnosis of a mass in the area of the kidney was confirmed in three cases, in two animals the renal origin of the masses was determined by ultrasound examination. Because a renal neoplasm is a pain-inducing disease with a high risk of metastases in domestic animals, a prompt nephrectomy should be performed when azotaemia is absent.

  13. Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region.

    PubMed

    Limon, Georgina; Gonzales-Gustavson, Eloy A; Gibson, Troy J

    2016-01-01

    Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO2) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO2 stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs.

  14. Temperature Preference in IAF Hairless and Hartley Guinea Pigs (Cavia porcellus).

    PubMed

    Kleven, Gale A; Joshi, Prianca

    2016-03-01

    The Hairless strain of guinea pigs (Cavia porcellus) is the result of a spontaneous recessive mutation first identified at the Institute Armand Frappier (IAF) in 1978. Despite the longstanding availability of this strain, little is known about its thermoregulatory behavior. The aim of this study was to determine temperature preference in Hartley and Hairless guinea pigs by observing each strain in a ring-shaped apparatus containing a nonlinear temperature gradient. Temperatures were maintained by separately controlled heating mats lining the apparatus. Set point temperatures ranged from 24 to 38 °C. Guinea pigs (Hartley female, Hairless female, and Hairless male guinea pigs; n = 8 each group) were placed either singly or in pairs at 1 of the 8 randomized starting points within the apparatus. Subjects were observed for 30 min and coded for location within the temperature gradient by both frequency and duration. When placed singly in the apparatus, all 3 groups spent more time in the 30 °C zones. However, when placed as pairs with a cagemate, Hartley female guinea pigs spent more time in the cooler range of temperatures from 24 to 30 °C, whereas Hairless guinea pigs preferred a range of 30 to 38 °C. These results confirm a temperature preference of 30 ± 2 °C for both Hartley and Hairless guinea pigs when singly housed. However, data from the paired housing condition suggest that context plays an important role in thermoregulatory behavior.

  15. Temperature Preference in IAF Hairless and Hartley Guinea Pigs (Cavia porcellus)

    PubMed Central

    Kleven, Gale A; Joshi, Prianca

    2016-01-01

    The Hairless strain of guinea pigs (Cavia porcellus) is the result of a spontaneous recessive mutation first identified at the Institute Armand Frappier (IAF) in 1978. Despite the longstanding availability of this strain, little is known about its thermoregulatory behavior. The aim of this study was to determine temperature preference in Hartley and Hairless guinea pigs by observing each strain in a ring-shaped apparatus containing a nonlinear temperature gradient. Temperatures were maintained by separately controlled heating mats lining the apparatus. Set point temperatures ranged from 24 to 38 °C. Guinea pigs (Hartley female, Hairless female, and Hairless male guinea pigs; n = 8 each group) were placed either singly or in pairs at 1 of the 8 randomized starting points within the apparatus. Subjects were observed for 30 min and coded for location within the temperature gradient by both frequency and duration. When placed singly in the apparatus, all 3 groups spent more time in the 30 °C zones. However, when placed as pairs with a cagemate, Hartley female guinea pigs spent more time in the cooler range of temperatures from 24 to 30 °C, whereas Hairless guinea pigs preferred a range of 30 to 38 °C. These results confirm a temperature preference of 30 ± 2 °C for both Hartley and Hairless guinea pigs when singly housed. However, data from the paired housing condition suggest that context plays an important role in thermoregulatory behavior. PMID:27025807

  16. Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region

    PubMed Central

    Limon, Georgina; Gonzales-Gustavson, Eloy A.; Gibson, Troy J.

    2016-01-01

    Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO2) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO2 stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs. PMID:26963642

  17. A First Generation Comparative Chromosome Map between Guinea Pig (Cavia porcellus) and Humans

    PubMed Central

    Romanenko, Svetlana A.; Perelman, Polina L.; Trifonov, Vladimir A.; Serdyukova, Natalia A.; Li, Tangliang; Fu, Beiyuan; O’Brien, Patricia C. M.; Ng, Bee L.; Nie, Wenhui; Liehr, Thomas; Stanyon, Roscoe; Graphodatsky, Alexander S.; Yang, Fengtang

    2015-01-01

    The domesticated guinea pig, Cavia porcellus (Hystricomorpha, Rodentia), is an important laboratory species and a model for a number of human diseases. Nevertheless, genomic tools for this species are lacking; even its karyotype is poorly characterized. The guinea pig belongs to Hystricomorpha, a widespread and important group of rodents; so far the chromosomes of guinea pigs have not been compared with that of other hystricomorph species or with any other mammals. We generated full sets of chromosome-specific painting probes for the guinea pig by flow sorting and microdissection, and for the first time, mapped the chromosomal homologies between guinea pig and human by reciprocal chromosome painting. Our data demonstrate that the guinea pig karyotype has undergone extensive rearrangements: 78 synteny-conserved human autosomal segments were delimited in the guinea pig genome. The high rate of genome evolution in the guinea pig may explain why the HSA7/16 and HSA16/19 associations presumed ancestral for eutherians and the three syntenic associations (HSA1/10, 3/19, and 9/11) considered ancestral for rodents were not found in C. porcellus. The comparative chromosome map presented here is a starting point for further development of physical and genetic maps of the guinea pig as well as an aid for genome assembly assignment to specific chromosomes. Furthermore, the comparative mapping will allow a transfer of gene map data from other species. The probes developed here provide a genomic toolkit, which will make the guinea pig a key species to unravel the evolutionary biology of the Hystricomorph rodents. PMID:26010445

  18. Form-deprivation myopia in the guinea pig (Cavia porcellus).

    PubMed

    Howlett, Marcus H C; McFadden, Sally A

    2006-01-01

    Form deprivation (FD) was induced in 61 guinea pigs with a diffuser worn on one eye. The form-deprived eye elongated and developed myopia within 6 days in animals raised under a 12:12 h light/dark cycle, but not when reared in darkness. After 11 days of FD, the average eye was -6.6 D more myopic and 146 microm longer than its fellow eye. Initially the myopia was mostly from vitreous chamber elongation, but with longer periods of FD, corneal power increases predominated. These effects were confirmed in schematic eyes. After a delay, FD also elongated the vitreous chamber of the non-deprived eye. The myopia rapidly abated once the diffusers were removed (65% within 24 h) due to inhibition of elongation and choroidal thickening. The guinea pig provides a fast mammalian model of FD myopia and corneal curvature regulation.

  19. Bitter avoidance in guinea pigs (Cavia porcellus) and mice (Mus musculus and Peromyscus leucopus).

    PubMed

    Field, Kristin L; Beauchamp, Gary K; Kimball, Bruce A; Mennella, Julie A; Bachmanov, Alexander A

    2010-11-01

    Rejection of bitter substances is common in many species and may function to protect an animal from ingestion of bitter-tasting toxins. Since many plants are bitter, it has been proposed that high tolerance for bitterness would be adaptive for herbivores. Earlier studies conducted on herbivorous guinea pigs (Cavia porcellus) have been used to support this proposal. We tested guinea pigs with bitter plant secondary metabolites (salicin, caffeine, quinine hydrochloride) and bitter protein hydrolysates (two types of hydrolyzed casein, hydrolyzed soy) in a series of two-choice preference tests. For comparison, we tested two nonherbivorous mouse species (Mus musculus and Peromyscus leucopus). Guinea pigs did show weaker avoidance of quinine hydrochloride than did the mice, confirming predictions generated from earlier work. However, guinea pigs had similar responses to caffeine as did Peromyscus. Both of these species showed weaker avoidance responses than Mus to 10 mM caffeine. For salicin, guinea pigs were the only species to avoid it at 10 mM and their preference scores at this concentration were significantly lower than for the two mice species. Guinea pigs avoided all of the protein hydrolysates more strongly than the other species. Responses to the protein hydrolysates did not reflect the patterns observed with the simple bitter compounds, suggesting that other properties of these complex stimuli may be responsible for guinea pig avoidance of them. Our results suggest caution in accepting, without further empirical support, the premise that guinea pigs (and herbivores in general) have a generalized reduced bitter sensitivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  20. Congenital malformations caused by Stryphnodendron fissuratum (Leg. Mimosoideae) in guinea pigs (Cavia porcellus).

    PubMed

    Macedo, Josenaldo S; Rocha, Brena P; Colodel, Edson M; Freitas, Sílvio H; Dória, Renata G S; Riet-Correa, Franklin; Evêncio-Neto, Joaquim; Mendonça, Fábio S

    2015-11-01

    The aim of this study was to evaluate the toxicity of Stryphnodendron fissuratum pods in guinea pigs (Cavia porcellus) and test the hypothesis that this plant has teratogenic effects. Thus, sixteen guinea pigs were randomly divided into four groups of four animals each. Groups 10, 20 and 40 consisted of guinea pigs that received commercial food that contained crushed pods of S. fissuratum at concentrations of 10, 20 and 40 g/kg, respectively, during the period of organogenesis. Control group consisted of guinea pigs under the same management conditions that did not receive crushed pods of S. fissuratum in their food. In all experimental groups, the main clinical signs of poisoning consisted of anorexia, prostration, absence of vocalizations, alopecia, diarrhea, and abortions within the adult guinea pigs. Those that did not abort gave birth to weak, malnourished pups, some of which had fetal malformations. The main teratogenic changes consisted of eventration, arthrogryposis, amelia of the forelimbs, anophthalmia, microphthalmia, anotia and agnathia. The reductions in the number of offspring and the malformations observed in the experimental groups suggest that S. fissuratum affects fetal development and is teratogenic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Morphological and immunohistochemical characterization of spontaneous thyroid gland neoplasms in guinea pigs (Cavia porcellus).

    PubMed

    Gibbons, P M; Garner, M M; Kiupel, M

    2013-03-01

    Reports of thyroid gland neoplasms in guinea pigs (Cavia porcellus) are rare, but thyroid tumors are among the most common neoplasms seen in cases submitted to Northwest ZooPath. This report describes the histological and immunohistochemical characteristics of thyroid neoplasms and lists the concurrent conditions found in guinea pig cases submitted to Northwest ZooPath during 1998 to 2008. Of 526 guinea pig case submissions, 19 had thyroid neoplasms. The most common clinical findings included a palpable mass on the ventral neck and progressive weight loss. Neoplasms were removed as an excisional biopsy from 7 guinea pigs, and 3 of these animals died within a few days after surgery. Radiographic mineral density was detected in 2 masses. Five of the neoplasms were reported as cystic; 5 were black or a dark color. Histologically, the neoplasms were classified as macrofollicular thyroid adenoma (8), thyroid cystadenoma (1), papillary thyroid adenoma (3), follicular thyroid carcinoma (5), follicular-compact thyroid carcinoma (1), and small-cell thyroid carcinoma (1). Osseous metaplasia was present in 8 neoplasms, and myeloid hyperplasia was present in 1 neoplasm. All 19 neoplasms were positive for thyroid transcription factor 1 and thyroglobulin but negative for parathyroid hormone and calcitonin. Numerous concurrent diseases, including hepatopathies, cardiomyopathies, and nephropathies, were present and considered to be the cause of death in many cases. Research is needed to determine the appropriate modalities for antemortem diagnosis and treatment and whether thyroid disease plays a role in the pathogenesis of chronic degenerative diseases in guinea pigs.

  2. Impact of azithromycin resistance mutations on the virulence and fitness of Chlamydia caviae in guinea pigs.

    PubMed

    Binet, Rachel; Bowlin, Anne K; Maurelli, Anthony T; Rank, Roger G

    2010-03-01

    Azithromycin (AZM) is a major drug used in the treatment and prophylaxis of infections caused by Chlamydia, yet no significant clinical resistance has been reported for these obligate intracellular bacteria. Nevertheless, spontaneous AZM resistance (Azm(r)) arose in vitro at frequencies ranging from 3 x 10(-8) to 8 x 10(-10) for clonal isolates of Chlamydia caviae, which is a natural pathogen of guinea pigs. Sequencing of the unique 23S rRNA gene copy in 44 independent Azm(r) isolates identified single mutations at position A(2058) or A(2059) (Escherichia coli numbering system). While SP(6)AZ(1) (A(2058)C) and SP(6)AZ(2) (A(2059)C) Azm(r) mutants showed growth defects in cell culture and were less pathogenic in the guinea pig ocular infection model than in the parent SP(6), the three isogenic C. caviae isolates grew equally well in the animal. On the other hand, coinoculation of the C. caviae parent strain with one of the Azm(r) strains was detrimental for the mutant strain. This apparent lack of association between pathology and bacterial load in vivo showed that virulence of the two Azm(r) mutants of C. caviae was attenuated. While chlamydial growth in vitro reflects the ability of the bacteria to multiply in permissive cells, survival in the host is a balance between cellular multiplication and clearance by the host immune system. The obligate intracellular nature of Chlamydia may therefore limit emergence of resistance in vivo due to the strength of the immune response induced by the wild-type antibiotic-sensitive bacteria at the time of antibiotic treatment.

  3. Isolation induced changes in Guinea Pig Cavia porcellus pup distress whistles.

    PubMed

    Monticelli, Patrícia F; Tokumaru, Rosana S; Ades, César

    2004-06-01

    Guinea Pig Cavia porcellus pups emit high-pitched distress whistles when separated from their mother. In order to assess the influence of the duration of a brief isolation period on whistle acoustic structure, we recorded the distress whistles of six 8-day old pups separated for 15 min from their group in a novel environment and compared the mean values of the first and last 30 whistle notes. Acoustic analysis revealed, throughout the session, a significant decrease in whistle duration, an increase in mean frequency and a tendency for a decrease in number of harmonics in the first part of the note. Results demonstrate that, throughout a brief isolation period, the vocal response of Guinea Pig pups to isolation undergoes structural changes possibly related to time-dependent changes in motivational state.

  4. [Dermatophyte colonization on guinea pigs (Cavia porcellus) kept in pet stores. First report from Santiago, Chile].

    PubMed

    Thomson, Pamela; Monsalves, Pamela; Maier, Liliana; Silva, Víctor

    2015-01-01

    Dermatophytes are pathogenic fungi that can be present in the flora of mammals, such as dogs, cats and rodents, which can be a source and transmission vehicle to other hosts, including humans. In Chile, there is a steady increase of acquiring guinea pigs (Cavia porcellus) as pets, with no local studies on their colonization by dermatophytes. To determine the presence of dermatophytes on clinically healthy guinea pigs, kept in pet stores in Santiago, Chile. A total of 52 clinically healthy animals were studied using the method by Mariat and Tapia (1966). The specimen culture and identification of the dermatophytes were performed using classical mycological procedures. Four guinea pigs (7.7%) out of 52 were colonized by dermatophytes, and were identified as Trichophyton mentagrophytes (3 cases) and Trichophyton verrucosum (one case). This study shows, for the first time in Chile, that guinea pigs can be colonized by dermatophytes, which should alert administrators of pet stores, veterinarians and physicians, to keep this in mind when purchasing or looking after this type of pet in a veterinary office. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  5. Draft Genome Sequence of Streptococcus caviae Strain Cavy grass 6T, Isolated from Domesticated Guinea Pig Fecal Samples

    PubMed Central

    Palakawong Na Ayudthaya, Susakul; Marshall, Ian P. G.; Schreiber, Lars

    2017-01-01

    ABSTRACT Streptococcus caviae strain Cavy grass 6T, isolated from fecal samples of pet guinea pigs, can metabolize a range of plant mono- and disaccharides, as well as polymeric carbohydrates. Here, we report the draft genome sequence of this strain, which comprises 2.11 Mb. PMID:28360157

  6. Drinking preferences in chinchillas (Chinchilla laniger), degus (Octodon degu) and guinea pigs (Cavia porcellus).

    PubMed

    Hagen, K; Clauss, M; Hatt, J-M

    2014-10-01

    Chinchilla (Chinchilla laniger), degus (Octodon degus) and guinea pigs (Cavia porcellus) are South American rodents living in a semi-arid habitat with varying, species-specific adaptations to water deprivation. Nonetheless, several diseases have been linked to insufficient water intake when these species are kept as pets, such as urolithiasis or obstipation. This study evaluated preferences for drinking systems. Six animals of each species were given a choice between an open dish and a nipple drinker. Food intake and water intake were measured daily for 13 days. Chinchillas in this study had significantly lower water intakes than the other two species, indicating particular species-specific adaptations to aridity. All chinchillas favoured open dishes, whereas the degus and guinea pigs had variable individual preferences. Water intake of chinchillas was similar or higher in this study than in previous studies where nipple drinkers were used. The results indicate that degus and guinea pigs can meet their drinking water needs with nipple drinkers; for chinchillas, other drinking systems may be more adequate.

  7. Validation of a Behavioral Ethogram for Assessing Postoperative Pain in Guinea Pigs (Cavia porcellus)

    PubMed Central

    Dunbar, Misha L; David, Emily M; Aline, Marian R; Lofgren, Jennifer L

    2016-01-01

    Although guinea pigs (Cavia porcellus) have been used in research for more than a century and remain the most prevalent USDA-covered species, little has been elucidated regarding the recognition of clinical pain or analgesic efficacy in this species. We sought to assess pain in guinea pigs by using newer, clinically relevant methods that have been validated in other rodent species: the behavioral ethogram and cageside proxy indicator. In this study, 10 male guinea pigs underwent electronic von Frey testing of nociception, remote videorecording of behavior, and cageside assessment by using time-to-consumption (TTC) of a preferred treat test. These assessments were performed across 2 conditions (anesthesia only and castration surgery under anesthesia) at 3 time points (2, 8, and 24 h after the event). The anesthesia only condition served to control for the nonpainful but potentially distressing components of the surgical experience. Compared with those after anesthesia only conditions, subtle body movements were increased and nociceptive thresholds were decreased at 2 and 8 h after surgery. At 24 h, neither subtle body movement behaviors nor nociceptive thresholds differed between the 2 conditions. In contrast, TTC scores did not differ between the anesthesia only and surgery conditions at any time point, underscoring the challenge of identifying pain in this species through cageside evaluation. By comparing ethogram scores with measures of nociception, we validated select behaviors as pain-specific. Therefore, our novel ethogram allowed us to assess postoperative pain and may further serve as a platform for future analgesia efficacy studies in guinea pigs. PMID:26817977

  8. Validation of a Behavioral Ethogram for Assessing Postoperative Pain in Guinea Pigs (Cavia porcellus).

    PubMed

    Dunbar, Misha L; David, Emily M; Aline, Marian R; Lofgren, Jennifer L

    2016-01-01

    Although guinea pigs (Cavia porcellus) have been used in research for more than a century and remain the most prevalent USDA-covered species, little has been elucidated regarding the recognition of clinical pain or analgesic efficacy in this species. We sought to assess pain in guinea pigs by using newer, clinically relevant methods that have been validated in other rodent species: the behavioral ethogram and cageside proxy indicator. In this study, 10 male guinea pigs underwent electronic von Frey testing of nociception, remote videorecording of behavior, and cageside assessment by using time-to-consumption (TTC) of a preferred treat test. These assessments were performed across 2 conditions (anesthesia only and castration surgery under anesthesia) at 3 time points (2, 8, and 24 h after the event). The anesthesia only condition served to control for the nonpainful but potentially distressing components of the surgical experience. Compared with those after anesthesia only conditions, subtle body movements were increased and nociceptive thresholds were decreased at 2 and 8 h after surgery. At 24 h, neither subtle body movement behaviors nor nociceptive thresholds differed between the 2 conditions. In contrast, TTC scores did not differ between the anesthesia only and surgery conditions at any time point, underscoring the challenge of identifying pain in this species through cageside evaluation. By comparing ethogram scores with measures of nociception, we validated select behaviors as pain-specific. Therefore, our novel ethogram allowed us to assess postoperative pain and may further serve as a platform for future analgesia efficacy studies in guinea pigs.

  9. Guinea pig (Cavia porcellus) drinking preferences: do nipple drinkers compensate for behaviourally deficient diets?

    PubMed

    Balsiger, A; Clauss, M; Liesegang, A; Dobenecker, B; Hatt, J-M

    2017-10-01

    When offered diets with hay ad libitum, rabbits (Oryctolagus cuniculus) clearly prefer open dishes over nipple drinkers, but whether this preference also applies in guinea pigs (Cavia porcellus) is unsure. We tested the drinker preference of 10 guinea pigs when offered open dishes (OD) and nipple drinkers (ND) simultaneously and measured the amount of water consumed by each animal on four different diets (grass hay 100%, or as 10% of intake on diets of fresh parsley, seed mix or pelleted complete feed, respectively) on either of the drinking systems. All animals ingested the hay portion of the combined diets first. The amount of water consumed differed significantly between individual animals. Animals drank less water on parsley than on the other diets. Nine of 10 animals clearly preferred ND when having a choice, and eight of these drank more when on ND only. The difference between the drinking systems was not consistent across all diets: on hay, similar amounts of water were drunk when on OD or ND only. Differences in water intake were reflected in urine production. Because drinking from ND in guinea pigs involves jaw movements similar to those in chewing, the results could suggest that when motivation for oral processing behaviour is not satisfied by a diet, animals may respond in using ND beyond physiological water necessity. Whereas physiological water requirements are probably better investigated with other drinking systems due to a possible overestimation when using ND, offering ND to pet guinea pigs most likely offers a form of behavioural enrichment that at the same time may increase water intake and hence act as prophylaxis against urolithiasis. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  10. A comparative analysis of the intestinal metagenomes present in guinea pigs (Cavia porcellus) and humans (Homo sapiens)

    PubMed Central

    2012-01-01

    Background Guinea pig (Cavia porcellus) is an important model for human intestinal research. We have characterized the faecal microbiota of 60 guinea pigs using Illumina shotgun metagenomics, and used this data to compile a gene catalogue of its prevalent microbiota. Subsequently, we compared the guinea pig microbiome to existing human gut metagenome data from the MetaHIT project. Results We found that the bacterial richness obtained for human samples was lower than for guinea pig samples. The intestinal microbiotas of both species were dominated by the two phyla Bacteroidetes and Firmicutes, but at genus level, the majority of identified genera (320 of 376) were differently abundant in the two hosts. For example, the guinea pig contained considerably more of the mucin-degrading Akkermansia, as well as of the methanogenic archaea Methanobrevibacter than found in humans. Most microbiome functional categories were less abundant in guinea pigs than in humans. Exceptions included functional categories possibly reflecting dehydration/rehydration stress in the guinea pig intestine. Finally, we showed that microbiological databases have serious anthropocentric biases, which impacts model organism research. Conclusions The results lay the foundation for future gastrointestinal research applying guinea pigs as models for humans. PMID:23020652

  11. A comparative analysis of the intestinal metagenomes present in guinea pigs (Cavia porcellus) and humans (Homo sapiens).

    PubMed

    Hildebrand, Falk; Ebersbach, Tine; Nielsen, Henrik Bjørn; Li, Xiaoping; Sonne, Si Brask; Bertalan, Marcelo; Dimitrov, Peter; Madsen, Lise; Qin, Junjie; Wang, Jun; Raes, Jeroen; Kristiansen, Karsten; Licht, Tine Rask

    2012-09-28

    Guinea pig (Cavia porcellus) is an important model for human intestinal research. We have characterized the faecal microbiota of 60 guinea pigs using Illumina shotgun metagenomics, and used this data to compile a gene catalogue of its prevalent microbiota. Subsequently, we compared the guinea pig microbiome to existing human gut metagenome data from the MetaHIT project. We found that the bacterial richness obtained for human samples was lower than for guinea pig samples. The intestinal microbiotas of both species were dominated by the two phyla Bacteroidetes and Firmicutes, but at genus level, the majority of identified genera (320 of 376) were differently abundant in the two hosts. For example, the guinea pig contained considerably more of the mucin-degrading Akkermansia, as well as of the methanogenic archaea Methanobrevibacter than found in humans. Most microbiome functional categories were less abundant in guinea pigs than in humans. Exceptions included functional categories possibly reflecting dehydration/rehydration stress in the guinea pig intestine. Finally, we showed that microbiological databases have serious anthropocentric biases, which impacts model organism research. The results lay the foundation for future gastrointestinal research applying guinea pigs as models for humans.

  12. Comparison of fibre digestion and digesta retention time between nutrias (Myocaster coypus) and guinea-pigs (Cavia porcellus).

    PubMed

    Sakaguchi, E; Nabata, A

    1992-11-01

    1. Digestibilities of feed, and transit and retention time of fluid and particle digesta marker measured in nutrias (Myocaster coypus) and guinea-pigs (Cavia porcellus) fed on a diet containing 50% alfalfa. 2. The digestibility of fibre was higher in the nutria, along with the longer retention time of digesta. 3. The liquid and particle marker were similarly excreted, suggesting no separation mechanism in the gastrointestinal tract of both the animals. 4. The apparent digestibility of protein in the nutria was superior to the guinea-pig and other small hindgut fermenters, suggesting that the contribution of coprophagy on protein nutrition of nutrias is significant.

  13. Coagulation and fibrinolysis in capybara (Hydrochaeris hydrochaeris), a close relative of the guinea-pig (Cavia porcellus).

    PubMed

    Leitão, D P; Polizello, A C; Rothschild, Z

    2000-01-01

    Fibrinolytic and coagulation properties of capybara (Hydrochaeris hydrochaeris, LINNAEUS, 1766) plasma were analysed and the results compared to the guinea-pig (Cavia porcellus), a close relative. Capybara fibrinogen was isolated and fibrinolysis of its plasma was carried out in a homologous system and with bovine fibrin. Undiluted plasma did not have fibrinolytic activity on fibrin plates; euglobulins gave a dose-related response. Zymography of capybara and guinea-pig plasma gave the same patterns of activity as human or bovine plasma. Human urokinase (UK) and tissue plasminogen activator (t-PA) produced lysis in capybara fibrin plates. Streptokinase (SK) (500 IU/ml) did not activate capybara or guinea-pig plasma. In this system, human plasma was extensively activated. Coagulation tests for both species of rodent were prolonged. The capybara showed values for prothrombin time (PT) shorter than activated thromboplastin time (APTT). The guinea-pig, as already shown, had longer PT values. Factors X and VII were very low for capybara and guinea-pig when tested using reference curves and diagnostic kits for human plasma. It is suggested that the capybara could be a valuable laboratory animal considering its size and closeness to the guinea-pig, and this could allow for the provision of materials from one single animal when convenient or necessary.

  14. Plasmid-cured Chlamydia caviae activates TLR2-dependent signaling and retains virulence in the guinea pig model of genital tract infection.

    PubMed

    Frazer, Lauren C; Darville, Toni; Chandra-Kuntal, Kumar; Andrews, Charles W; Zurenski, Matthew; Mintus, Margaret; AbdelRahman, Yasser M; Belland, Robert J; Ingalls, Robin R; O'Connell, Catherine M

    2012-01-01

    Loss of the conserved "cryptic" plasmid from C. trachomatis and C. muridarum is pleiotropic, resulting in reduced innate inflammatory activation via TLR2, glycogen accumulation and infectivity. The more genetically distant C. caviae GPIC is a natural pathogen of guinea pigs and induces upper genital tract pathology when inoculated intravaginally, modeling human disease. To examine the contribution of pCpGP1 to C. caviae pathogenesis, a cured derivative of GPIC, strain CC13, was derived and evaluated in vitro and in vivo. Transcriptional profiling of CC13 revealed only partial conservation of previously identified plasmid-responsive chromosomal loci (PRCL) in C. caviae. However, 2-deoxyglucose (2DG) treatment of GPIC and CC13 resulted in reduced transcription of all identified PRCL, including glgA, indicating the presence of a plasmid-independent glucose response in this species. In contrast to plasmid-cured C. muridarum and C. trachomatis, plasmid-cured C. caviae strain CC13 signaled via TLR2 in vitro and elicited cytokine production in vivo similar to wild-type C. caviae. Furthermore, inflammatory pathology induced by infection of guinea pigs with CC13 was similar to that induced by GPIC, although we observed more rapid resolution of CC13 infection in estrogen-treated guinea pigs. These data indicate that either the plasmid is not involved in expression or regulation of virulence in C. caviae or that redundant effectors prevent these phenotypic changes from being observed in C. caviae plasmid-cured strains.

  15. Plasmid-Cured Chlamydia caviae Activates TLR2-Dependent Signaling and Retains Virulence in the Guinea Pig Model of Genital Tract Infection

    PubMed Central

    Frazer, Lauren C.; Darville, Toni; Chandra-Kuntal, Kumar; Andrews, Charles W.; Zurenski, Matthew; Mintus, Margaret; AbdelRahman, Yasser M.; Belland, Robert J.; Ingalls, Robin R.; O'Connell, Catherine M.

    2012-01-01

    Loss of the conserved “cryptic” plasmid from C. trachomatis and C. muridarum is pleiotropic, resulting in reduced innate inflammatory activation via TLR2, glycogen accumulation and infectivity. The more genetically distant C. caviae GPIC is a natural pathogen of guinea pigs and induces upper genital tract pathology when inoculated intravaginally, modeling human disease. To examine the contribution of pCpGP1 to C. caviae pathogenesis, a cured derivative of GPIC, strain CC13, was derived and evaluated in vitro and in vivo. Transcriptional profiling of CC13 revealed only partial conservation of previously identified plasmid-responsive chromosomal loci (PRCL) in C. caviae. However, 2-deoxyglucose (2DG) treatment of GPIC and CC13 resulted in reduced transcription of all identified PRCL, including glgA, indicating the presence of a plasmid-independent glucose response in this species. In contrast to plasmid-cured C. muridarum and C. trachomatis, plasmid-cured C. caviae strain CC13 signaled via TLR2 in vitro and elicited cytokine production in vivo similar to wild-type C. caviae. Furthermore, inflammatory pathology induced by infection of guinea pigs with CC13 was similar to that induced by GPIC, although we observed more rapid resolution of CC13 infection in estrogen-treated guinea pigs. These data indicate that either the plasmid is not involved in expression or regulation of virulence in C. caviae or that redundant effectors prevent these phenotypic changes from being observed in C. caviae plasmid-cured strains. PMID:22292031

  16. S1 nuclease definition of highly repeated DNA sequences in the Guinea pig, Cavia porcellus.

    PubMed Central

    Hubbell, H R; Robberson, D L; Hsu, T C

    1979-01-01

    Native DNA of the Guinea pig, Cavia porcellus, purified from liver or tissue culture cells, was heat denatured and reassociated to a Cot value of 0.01 (equivalent Cot value of 7.2 x 10(-2)). The reassociated DNA was isolated by digestion with the single-strand DNA specific enzyme S1 nuclease. Spectrophotometric and radioactivity assays demonstrated that 24% of the total DNA was resistant to S1 nuclease treatment. Zero-time reassociation indicated that approximately 3% of the DNA was inverted repeat sequences. Thus, highly repeated sequences comprised 21% of the total genome. CsCl buoyant density ultracentrifugation indicated that this fraction was composed of both main band and satellite sequences. Although actinomycin D - CsCl density gradients failed to give significant separation of the repetitive sequences, distamycin A - CsCl gradients were able to fractionate the DNA into several overlapping bands. The heterogeneity of the repetitive DNA was further demonstrated by the first derivative plots calculated from their thermal denaturation profiles. This analysis revealed six major thermalytes which indicate that there may be at least six discrete components in the repetitive DNA. Images PMID:523322

  17. Study on postpartum estrus of guinea pigs (Cavia cobaya) using Anredera cordifolia leaf extract

    PubMed Central

    Wijayanti, D.; Setiatin, E. T.; Kurnianto, E.

    2017-01-01

    Aim: The purpose of this study was to determine the postpartum estrus cycle of guinea pigs (Cavia cobaya) using Anredera cordifolia leaf extract. Materials and Methods: Materials used were 8 males and 8 females of C. cobaya with body weight ranged 400-450 g. Mating ratio applied was 1:1. Treatments given were 0, 10, 50 and 90 mg of A. cordifolia leaf extract/head, designated as T0, T1, T2 and T3, respectively. Two females were subjected for each treatment. A. cordifolia leaf extract was administered orally from 10 days prepartum to 10 days postpartum. Observation of mating behavior, vulva morphology, and vaginal smear preparation was done in the afternoon for 10 days subsequence postpartum. Data were analyzed by univariate method and descriptively. Results: The results showed that the addition of A. cordifolia leaf extract 50 mg orally could accelerate the time of postpartum estrus based on the average frequency of mating behavior consisting of behavioral approach, allow the buck to sniffing her, mating positions, standing heat, lordosis position, and copulation. During estrus, vulva morphology was red color, had much mucus and no thin membrane covering vagina. There were a lot of superficial cells on vagina. Conclusion: The best treatment to accelerate occurring postpartum estrus was the addition of A. cordifolia leaf extract as many as 50 mg/head weight (T2) orally. PMID:28507407

  18. Renal failure in a guinea pig (Cavia porcellus) following ingestion of oxalate containing plants

    PubMed Central

    Holowaychuk, Marie K.

    2006-01-01

    A 1-year-old guinea pig presented with anorexia, lethargy, and weight loss, 1 week after ingesting a peace lily leaf. Laboratory findings were suggestive of renal failure and included elevated blood urea nitrogen and creatinine with concurrent isosthenuria. The guinea pig was euthanized 1 month later due to worsening clinical signs. PMID:16933558

  19. Blastocyst recovery and multifactorial gene expression analysis in the wild guinea pig (Cavia aperea).

    PubMed

    Hribal, Romy; Guenther, Anja; Rübensam, Kathrin; Jewgenow, Katarina

    2016-09-15

    The expression of specific developmentally important genes in preimplantation embryos is an accepted marker for unraveling the influence of single factors in studies that are mostly related to artificial reproduction techniques. Such studies, however, often reveal high levels of heterogeneity between single embryos, independently of the influence of factors of interest. A possible explanation for this variation could be the large variety of physiological and environmental factors to which early embryos are exposed and their ability to react to them. Here, we investigated several potentially important parameters of development at the same time, in blastocysts of the wild guinea pig (Cavia aperea) generated in vivo after natural mating. The optimal time for flushing fully developed blastocysts was between 123 and 126 hours after mating. The abundance of POU5F1 (P = 0.042), BAX (P < 0.001), SLC2A1 (P = 0.017), and DNMT3A (P < 0.001) mRNA changed significantly over time after mating. The number of sibling embryos present influenced STAT3 levels significantly (P = 0.02). Levels of BAX and POU5F1 were significantly affected by season (P = 0.03 and 0.04). The temporal pattern of SLC2A1 levels was significantly altered both after feeding a protein-deficient diet (P = 0.04) and temperature treatment (P = 0.04) of the sire. In addition, the identity of the father had a significant influence on POU5F1 (P = 0.049) and STAT3 (P < 0.001) mRNA abundances. These data report that the expression of specific genes in early embryos reflects the entire heterogeneity of their surroundings and that it is a plastic reaction toward a multifactorial environment. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Parasitological and histopathological effects of immunosuppression in guinea-pigs (Cavia porcellus) experimentally infected with Schistosoma haematobium.

    PubMed

    Okeke, O C; Ubachukwu, P O; Okafor, F C; Shoyinka, S V O

    2012-12-01

    The parasitological and histopathological effects of immunosuppression in guinea-pigs (Cavia porcellus) experimentally infected with Schistosoma haematobium were studied. A total of 16 guinea-pigs were divided into four groups (four per group): non-immunosuppressed, non-infected group (NN); immunosuppressed, non-infected group (IN); immunosuppressed, infected group (II); non-immunosuppressed, infected group (NI). The IN and II groups were immunosuppressed with 5 mg/kg prednisolone while the II and NI animals were infected with 200-300 S. haematobium cercariae. Excretion of eggs in urine/faeces, worm burden and histopathology of some vital organs of the guinea-pigs were studied. Eggs of S. haematobium were observed in the urine of the NI and II groups from 9 weeks post-infection and in faeces from 10 and 13 weeks post-infection for the NI and II groups, respectively. However, II animals excreted more viable eggs in urine and faeces than those of the NI group. Worm recovery at 14 weeks post-infection showed that NI and II guinea-pigs had more female worms than male worms and a greater proportion of worm recovery for NI animals was of immature worms. Significant differences (P < 0.05) existed between female, male and immature worm burden of the two groups but not in their total worm burden (P>0.05). Histological changes, which were notably reactions to adult S. haematobium worms, were observed in the organs of the NI and II groups but these changes were seen more in the organs of the immunosuppressed, infected (II) than in the non-immunosuppressed, infected (NI) guinea-pigs. The results suggest that immunosuppression before infection increased worm survival and had a moderate effect on liver and bladder histology of S. haematobium infected guinea-pigs.

  1. Hyperendemic Campylobacter jejuni in guinea pigs (Cavia porcellus) raised for food in a semi-rural community of Quito, Ecuador

    PubMed Central

    Graham, Jay P.; Vasco, Karla; Trueba, Gabriel

    2016-01-01

    Summary Domestic animals and animal products are the source of pathogenic Campylobacter jejuni and C. coli in industrialized countries, yet little is known about the transmission of these bacteria in developing countries. Guinea pigs (Cavia porcellus) are commonly raised for food in the Andean region of South America, however, limited research has characterized this rodent as a reservoir of zoonotic enteric pathogens. In this study, we examined the prevalence of Campylobacter spp. in 203 fecal samples from domestic animals of 59 households in a semi-rural parish of Quito, Ecuador. Of the twelve animal species studied, guinea pigs showed the highest prevalence of C. jejuni (n = 39/40; 97.5%). Multilocus sequence typing (MLST) was used to characterize the genetic relationship of C. jejuni from domestic animals and 21 sequence types (STs) were identified. The majority of STs from guinea pigs appeared to form new clonal complexes that were not related to STs of C. jejuni isolated from other animal species and shared only a few alleles with other C. jejuni previously characterized. The study identifies guinea pigs as a major reservoir of C. jejuni and suggests that some C. jejuni strains are adapted to this animal species. PMID:27043446

  2. Hyperendemic Campylobacter jejuni in guinea pigs (Cavia porcellus) raised for food in a semi-rural community of Quito, Ecuador.

    PubMed

    Graham, Jay P; Vasco, Karla; Trueba, Gabriel

    2016-06-01

    Domestic animals and animal products are the source of pathogenic Campylobacter jejuni and C. coli in industrialized countries, yet little is known about the transmission of these bacteria in developing countries. Guinea pigs (Cavia porcellus) are commonly raised for food in the Andean region of South America, however, limited research has characterized this rodent as a reservoir of zoonotic enteric pathogens. In this study, we examined the prevalence of Campylobacter spp. in 203 fecal samples from domestic animals of 59 households in a semi-rural parish of Quito, Ecuador. Of the twelve animal species studied, guinea pigs showed the highest prevalence of C. jejuni (n = 39/40; 97.5%). Multilocus sequence typing (MLST) was used to characterize the genetic relationship of C. jejuni from domestic animals and 21 sequence types (STs) were identified. The majority of STs from guinea pigs appeared to form new clonal complexes that were not related to STs of C. jejuni isolated from other animal species and shared only a few alleles with other C. jejuni previously characterized. The study identifies guinea pigs as a major reservoir of C. jejuni and suggests that some C. jejuni strains are adapted to this animal species. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Injury thresholds for topical-cream-coated skin of hairless guinea pigs (cavia porcellus) in the near-infrared region

    NASA Astrophysics Data System (ADS)

    Pocock, Ginger M.; Zohner, Justin J.; Stolarski, David J.; Buchanan, Kelvin C.; Jindra, Nichole M.; Figueroa, Manuel A.; Chavey, Lucas J.; Imholte, Michelle L.; Thomas, Robert J.; Rockwell, Benjamin A.

    2006-02-01

    The reflectance and absorption of the skin plays a vital role in determining how much radiation will be absorbed by human tissue. Any substance covering the skin would change the way radiation is reflected and absorbed and thus the extent of thermal injury. Hairless guinea pigs (cavia porcellus) in vivo were used to evaluate how the minimum visible lesion threshold for single-pulse laser exposure is changed with a topical agent applied to the skin. The ED 50 for visible lesions due to an Er: glass laser at 1540-nm with a pulse width of 50-ns was determined, and the results were compared with model predictions using a skin thermal model. The ED50 is compared with the damage threshold of skin coated with a highly absorbing topical cream at 1540 nm to determine its effect on damage pathology and threshold. The ED 50 for the guinea pig was then compared to similar studies using Yucatan minipigs and Yorkshire pigs at 1540-nm and nanosecond pulse duration. 1,2 The damage threshold at 24-hours of a Yorkshire pig for a 2.5-3.5-mm diameter beam for 100 ns was 3.2 Jcm -2; very similar to our ED 50 of 3.00 Jcm -2 for the hairless guinea pigs.

  4. Hematological assessment in pet guinea pigs (Cavia porcellus): blood sample collection and blood cell identification.

    PubMed

    Zimmerman, Kurt; Moore, David M; Smith, Stephen A

    2015-01-01

    Pet guinea pigs are presented to veterinary clinics for routine care and treatment of clinical diseases. In addition to obtaining clinical history and exam findings, diagnostic testing may be required, including hematological assessments. This article describes common blood collection methods, including venipuncture sites, the volume of blood that can be safely collected, and handling of the blood. Hematological parameters for normal guinea pigs are provided for comparison with in-house or commercial test results. A description of the morphology of guinea pig leukocytes is provided to assist in performing a differential count.

  5. Hematological Assessment in Pet Guinea Pigs (Cavia porcellus): Blood Sample Collection and Blood Cell Identification.

    PubMed

    Zimmerman, Kurt; Moore, David M; Smith, Stephen A

    2015-09-01

    Pet guinea pigs are presented to veterinary clinics for routine care and treatment of clinical diseases. In addition to obtaining clinical history and exam findings, diagnostic testing may be required, including hematological assessments. This article describes common blood collection methods, including venipuncture sites, the volume of blood that can be safely collected, and handling of the blood. Hematological parameters for normal guinea pigs are provided for comparison with in-house or commercial test results. A description of the morphology of guinea pig leukocytes is provided to assist in performing a differential count.

  6. Evaluating the Clinical and Physiological Effects of Long Term Ultraviolet B Radiation on Guinea Pigs (Cavia porcellus)

    PubMed Central

    Watson, Megan K.; Stern, Adam W.; Labelle, Amber L.; Joslyn, Stephen; Fan, Timothy M.; Leister, Katie; Kohles, Micah; Marshall, Kemba; Mitchell, Mark A.

    2014-01-01

    Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (p<0.0001) between the UVB supplementation group (101.49±21.81 nmol/L) and the control group (36.33±24.42 nmol/L). An increased corneal thickness in both eyes was also found in the UVB supplementation compared to the control group (right eye [OD]: p<0.0001; left eye [OS]: p<0.0001). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing guinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended. PMID:25517408

  7. Evaluating the clinical and physiological effects of long term ultraviolet B radiation on guinea pigs (Cavia porcellus).

    PubMed

    Watson, Megan K; Stern, Adam W; Labelle, Amber L; Joslyn, Stephen; Fan, Timothy M; Leister, Katie; Kohles, Micah; Marshall, Kemba; Mitchell, Mark A

    2014-01-01

    Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (p<0.0001) between the UVB supplementation group (101.49±21.81 nmol/L) and the control group (36.33±24.42 nmol/L). An increased corneal thickness in both eyes was also found in the UVB supplementation compared to the control group (right eye [OD]: p<0.0001; left eye [OS]: p<0.0001). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing guinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended.

  8. Characterization of a novel parainfluenza virus, caviid parainfluenza virus 3, from laboratory guinea pigs (Cavia porcellus).

    PubMed

    Simmons, Joe H; Purdy, Gregory A; Franklin, Craig L; Trottier, Pierre; Churchill, Anthony E; Russell, Robert J; Besch-Williford, Cynthia L; Riley, Lela K

    2002-12-01

    A novel Respirovirus was isolated from nasopharyngeal swab specimens from clinically normal laboratory guinea pigs, and was characterized and named caviid parainfluenza virus 3 (CavPIV-3). The CavPIV-3 is enveloped, is 100 to 300 nm in diameter, and has a characteristic 15-nm-diameter chevron-shaped virus ribonucleocapsid protein. Sequence analysis of the fusion glycoprotein of CavPIV-3 revealed it to be 94% identical to human and guinea pig parainfluenza 3 (PIV-3) viruses and 80% identical to bovine PIV-3. To determine whether CavPIV-3 causes clinical disease in laboratory guinea pigs and to compare the serologic response of guinea pigs to CavPIV-3 and to other paramyxoviruses, an infection study was performed, in which groups of guinea pigs were inoculated with CavPIV-3, Sendai virus, simian virus 5 (SV-5), murine pneumonia virus (PVM), or bovine PIV-3 virus. During the course of the study, guinea pigs were maintained in an infectious disease suite, housed in Micro-Isolator cages, and were only manipulated under a laminar flow hood. Clinical signs of disease were not observed in any of the paramyxovirus-inoculated guinea pigs during the eight-week course of the study, and histologic signs of disease were not evident at necropsy eight weeks after inoculation. Guinea pigs inoculated with CavPIV-3, Sendai virus, PVM, and bovine PIV-3 developed robust homologous or heterologous serologic responses. In contrast, guinea pigs inoculated with SV-5 developed modest or equivocal serologic responses, as assessed by use of an enzyme-linked immunosorbent assay. Further, use of the SV-5 enzyme-linked immunosorbent assay resulted in the highest degree of non-specific reactivity among all of the paramyxovirus assays. In summary, CavPIV-3 is a novel guinea pig Respirovirus that subclinically infects laboratory guinea pigs, resulting in a robust serologic response, but no observed clinical or histologic disease. The CavPIV-3 fusion glycoprotein gene sequence is available from Gen

  9. The effects of early environmental conditions on the reproductive and somatic development of juvenile guinea pigs (Cavia aperea f. porcellus)

    PubMed Central

    Bauer, Barbara; Womastek, Irene; Dittami, John; Huber, Susanne

    2011-01-01

    Little is known about the effects of the early environment on the development of non-seasonally reproducing species like the domestic guinea pig (Cavia aperea f. porcellus). Although guinea pigs reproduce throughout the year, there is evidence for environmental sensitivity of their reproductive physiology. To investigate the sensitivity of juvenile body weight and puberty to differences in the prenatal and early postnatal environment, subjects were exposed to either of two experimental conditions mimicking seasonal variation: a long photoperiod with 25 °C ambient temperature (“LD/25 °C”), or a short photoperiod with 15 °C (“SD/15 °C”). Mean body weight of F1-males from LD/25 °C-conditions was higher than that of SD/15 °C-males during the whole pubertal period, although the difference was significant only during the early growth phase. Testosterone concentrations also differed significantly between the two treatment groups, pointing to an earlier pubertal onset in LD/25 °C- than SD/15 °C-males. In F1-females, treatment effects on body weight or age at first estrus were absent. This indicates that the somatic and reproductive development is more sensitive to early photoperiod and temperature conditions in male than female guinea pigs, and that other environmental factors may also play a crucial role for reproductive maturation in this species. PMID:17977535

  10. Evaluation of the infectivity and the persistence of Trichinella patagoniensis in muscle tissue of decomposing guinea pig (Cavia porcellus).

    PubMed

    Fariña, F; Pasqualetti, M; Ilgová, J; Cardillo, N; Ercole, M; Aronowicz, T; Krivokapich, S; Kašný, M; Ribicich, M

    2017-01-01

    Trichinella patagoniensis, a new species of Trichinella, is widespread in Argentina. The success of parasite transmission depends, among other factors, on the resistance of L1 larvae present in the muscle tissue (ML) of dead hosts undergoing the decomposition process in different environmental conditions. The aim of the present work was to study the infectivity of T. patagoniensis muscle larvae in Cavia porcellus and the capability of the parasite to survive in decomposed muscle tissue of guinea pigs subjected to different environmental conditions. Thirty-two female Ssi:AL guinea pigs were orally inoculated with 2000 ML of T. patagoniensis (ISS2311). All the animals were sacrificed 42 days post-infection. Twenty-six animals were eviscerated, and carcasses were placed on the surface of soil inside plastic boxes that were exposed to environmental conditions in the summer 2014-2015 and autumn of 2015 in Buenos Aires, Argentina. Carcasses from six animals were placed into a plastic box inside the refrigerator at a temperature of 4 °C. The muscle tissue samples from the carcasses were examined weekly for the presence of larvae, and the infectivity of recovered ML was tested in BALB/c mice. Our results showed for the first time the ability of T. patagoniensis to complete its life cycle in guinea pigs, thus serving as a potential natural host. Also, larvae of T. patagoniensis remained infective in muscle tissue for several weeks while undergoing decomposition under different environmental conditions.

  11. Tooth length and incisal wear and growth in guinea pigs (Cavia porcellus) fed diets of different abrasiveness.

    PubMed

    Müller, J; Clauss, M; Codron, D; Schulz, E; Hummel, J; Kircher, P; Hatt, J-M

    2015-06-01

    Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical 'bridge formation' of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  12. Expressed sequence tag analysis of guinea pig (Cavia porcellus) eye tissues for NEIBank

    PubMed Central

    Simpanya, Mukoma F.; Wistow, Graeme; Gao, James; David, Larry L.; Giblin, Frank J.

    2008-01-01

    Purpose To characterize gene expression patterns in guinea pig ocular tissues and identify orthologs of human genes from NEIBank expressed sequence tags. Methods RNA was extracted from dissected eye tissues of 2.5-month-old guinea pigs to make three unamplified and unnormalized cDNA libraries in the pCMVSport-6 vector for the lens, retina, and eye minus lens and retina. Over 4,000 clones were sequenced from each library and were analyzed using GRIST for clustering and gene identification. Lens crystallin EST data were validated using two-dimensional electrophoresis (2-DE), matrix assisted laser desorption (MALDI), and electrospray ionization mass spectrometry (ESIMS). Results Combined data from the three libraries generated a total of 6,694 distinctive gene clusters, with each library having between 1,000 and 3,000 clusters. Approximately 60% of the total gene clusters were novel cDNA sequences and had significant homologies to other mammalian sequences in GenBank. Complete cDNA sequences were obtained for many guinea pig lens proteins, including αA/αAinsert-, γN-, and γS-crystallins, lengsin and GRIFIN. The ratio of αA- to αB-crystallin on 2-DE gels was 8: 1 in the lens nucleus and 6.5: 1 in the cortex. Analysis of ESTs, genome sequence, and proteins (by MALDI), did not reveal any evidence for the presence of γD-, γE-, and γF-crystallin in the guinea pig. Predicted masses of many guinea pig lens crystallins were confirmed by ESIMS analysis. For the retina, orthologs of human phototransduction genes were found, such as Rhodopsin, S-antigen (Sag, Arrestin), and Transducin. The guinea-pig ortholog of NRL, a key rod photoreceptor-specific transcription factor, was also represented in EST data. In the ‘rest-of-eye’ library, the most abundant transcripts included decorin and keratin 12, representative of the cornea. Conclusions Genomic analysis of guinea pig eye tissues provides sequence-verified clones for future studies. Guinea pig orthologs of many human

  13. Effects of Changing to Individually Ventilated Caging on Guinea Pigs (Cavia porcellus)

    PubMed Central

    Giral, Marta; Armengol, Clara; Sánchez-Gómez, Sonia; Gavaldà, Amadeu

    2015-01-01

    The goal of this study was to evaluate the effect of changing to IVC housing on guinea pigs by recording several physiologic parameters in guinea pigs housed sequentially in open-top cages (OTC) and IVC. To register heart rate and locomotor activity, 10 male Dunkin–Hartley guinea pigs implanted with telemetric transmitters were moved from OTC to new, freshly prepared OTC or IVC and subsequently monitored by telemetry during the 4 d after the first cage change. Body weight and food consumption were measured twice during the study. Comparison of data from OTC- and IVC-housed guinea pigs showed no relevant differences in heart rate (mean ± 1 SD; 213 ± 10 bpm and 207 ± 9 bpm, respectively) at any time point. In contrast, locomotor activity varied: whereas activity during the first 4 h after the change of cage type was greater in IVC-housed animals, that during the following 24 h was greater in OTC but was similar between groups thereafter. Animals housed in OTC consumed more food than did those in IVC and, under both conditions, consumption was statistically related to body weight changes. Together, these results show that a change to IVC housing induced only transient increases in locomotor activity in guinea pigs without a marked increase in heart rate but with a decrease in food consumption. Because decreased food consumption was the only stress-associated sign during the 4-d observation, longer studies are needed to ascertain the importance of this finding. PMID:26045451

  14. Effects of Changing to Individually Ventilated Caging on Guinea Pigs (Cavia porcellus).

    PubMed

    Giral, Marta; Armengol, Clara; Sánchez-Gómez, Sonia; Gavaldà, Amadeu

    2015-05-01

    The goal of this study was to evaluate the effect of changing to IVC housing on guinea pigs by recording several physiologic parameters in guinea pigs housed sequentially in open-top cages (OTC) and IVC. To register heart rate and locomotor activity, 10 male Dunkin-Hartley guinea pigs implanted with telemetric transmitters were moved from OTC to new, freshly prepared OTC or IVC and subsequently monitored by telemetry during the 4 d after the first cage change. Body weight and food consumption were measured twice during the study. Comparison of data from OTC- and IVC-housed guinea pigs showed no relevant differences in heart rate (mean ± 1 SD; 213 ± 10 bpm and 207 ± 9 bpm, respectively) at any time point. In contrast, locomotor activity varied: whereas activity during the first 4 h after the change of cage type was greater in IVC-housed animals, that during the following 24 h was greater in OTC but was similar between groups thereafter. Animals housed in OTC consumed more food than did those in IVC and, under both conditions, consumption was statistically related to body weight changes. Together, these results show that a change to IVC housing induced only transient increases in locomotor activity in guinea pigs without a marked increase in heart rate but with a decrease in food consumption. Because decreased food consumption was the only stress-associated sign during the 4-d observation, longer studies are needed to ascertain the importance of this finding.

  15. Comparative study of 2 surgical techniques for castration of guinea pigs (Cavia porcellus)

    PubMed Central

    Guilmette, Josée; Langlois, Isabelle; Hélie, Pierre; de Oliveira El Warrak, Alexander

    2015-01-01

    The objective of this study was to compare 2 surgical approaches (scrotal or abdominal) for castration of guinea pigs and to investigate post-operative infection rates with either technique. Forty-eight guinea pigs were castrated by scrotal or abdominal technique after being randomly assigned to 1 of 2 groups (n = 24). Individuals were either castrated by an experienced exotic animal surgeon (n = 12) or by an experienced small animal surgeon (n = 12). Surgical wounds were evaluated daily before euthanasia for histological evaluation 2 wks after surgery. Post-operative infection rate was significantly higher in the scrotal group than in the abdominal group, with a higher rate for the experienced small animal surgeon. Castration of guinea pigs with the abdominal technique is significantly faster and has a significantly lower post-operative infection rate than the scrotal technique. PMID:26424914

  16. Studies on vertical transmission of Trichinella spiralis in experimentally infected guinea pigs (Cavia porcellus).

    PubMed

    Riva, Eliana; Fiel, Cesar; Bernat, Gisele; Muchiut, Sebastián; Steffan, Pedro

    2017-08-01

    An experimental study to enhance knowledge on the capability of Trichenella spiralis to pass from guinea pigs to progeny at different periods of pregnancy or lactation was performed. For this purpose, 18 female adult guinea pigs were inoculated with 100 or 1000 T. spiralis muscle larvae (ML) during early, late gestation and during lactation period. The presence of T. spiralis (ML) in mothers and newborns was studied through enzymatic digestion from muscle samples. ML were observed in 9 of 42 newborn guinea pigs and levels of infection were significantly higher when infections of mothers were done during late gestation (p = 0.0046) with the high infective dose (p = 0.0043). T. spiralis ML were not recovered from any of the newborns from mothers infected in the lactation period. Ten out of 18 infected mothers presented larvae 1 in their mammary glands. Muscle samples from the tongue and the masseter showed the highest larval burdens. These observations confirm previous reports on that ML of T. spiralis are capable to pass through placental tissues to reach and encyst in striated muscle groups of newborn guinea pigs. This study may also reinforce the importance of preventive programs to control trichinellosis in those endemic areas where pregnant women would have high risk of infection.

  17. Hypervitaminosis D and Metastatic Calcification in a Colony of Inbred Strain 13 Guinea Pigs, Cavia porcellus.

    PubMed

    Holcombe, H; Parry, N M; Rick, M; Brown, D E; Albers, T M; Refsal, K R; Morris, J; Kelly, R; Marko, S T

    2015-07-01

    A commercial diet fed to a colony of inbred strain 13 guinea pigs for approximately 6 weeks was subsequently recalled for excessive levels of vitamin D. Twenty-one of 62 animals exhibited clinical signs, including anorexia, lethargy, and poor body condition. Nine affected and 4 clinically normal animals were euthanized for further evaluation, including serum chemistry, urinalysis, and gross and/or histopathology. Macroscopic findings included white discoloration in multiple organs in 8 animals, and microscopic evaluation confirmed multiorgan mineralization in tissues from 7 animals. Serum 25-hydroxyvitamin D levels were elevated in 10 animals. Serum inorganic phosphorus and alkaline phosphatase levels were increased in all exposed animals; however, total calcium and ionized calcium levels were not significantly higher in exposed animals than in control strain 13 guinea pigs from a different institution. The data support a diagnosis of hypervitaminosis D with metastatic calcification. Following the diet recall, the remaining guinea pigs increased their food intake and regained body condition. Diagnostic testing of 8 animals euthanized approximately 3 months after returning to a normal diet demonstrated that serum parathyroid hormone remained significantly lower, and ionized calcium and ionized magnesium were significantly higher, in recovered animals compared to controls and exposed animals. These results indicate that diagnostic tests other than serum calcium are necessary for a diagnosis of hypervitaminosis D in guinea pigs. © The Author(s) 2014.

  18. Use of a Far-Infrared Active Warming Device in Guinea Pigs (Cavia porcellus).

    PubMed

    Zarndt, Bethany S; Buchta, Jessica N; Garver, Lindsey S; Davidson, Silas A; Rowton, Edgar D; Despain, Kenneth E

    2015-11-01

    Small mammals have difficulty maintaining body temperature under anesthesia. This hypothermia is a potential detriment not only to the health and comfort of the animal but also to the integrity of any treatment given or data gathered during the anesthetic period. Using an external warming device to assist with temperature regulation can mitigate these effects. In this study, we investigated the ability of an advanced warming device that uses far-infrared (FIR) heating and responds to real-time core temperature monitoring to maintain a normothermic core temperature in guinea pigs. Body temperatures were measured during 30 min of ketamine-xylazine general anesthesia with and without application of the heating device. The loss of core body heat from anesthetized guinea pigs under typical (unwarmed) conditions was significant, and this loss was almost completely mitigated by application of the FIR heating pad. The significant difference between the temperatures of the actively warmed guinea pigs as compared with the control group began as early as 14 min after anesthetic administration, leading to a 2.6 °C difference at 30 min. Loss of core body temperature was not correlated with animals' body weight; however, weight influences the efficiency of FIR warming slightly. These study results show that the FIR heating device accurately controls core body temperature in guinea pigs, therefore potentially alleviating the effects of body heat loss on animal physiology.

  19. Molecular cloning and characterization of TNFSF14 (LIGHT) and its receptor TNFRSF14 (HVEM) in guinea pig (Cavia porcellus).

    PubMed

    Li, Chunlan; Chen, Shanshan; Song, Jinyun; Liu, Hongyan; Gu, Wei; Ai, Hongxin; Zhao, Bo; Zhang, Shuangquan

    2013-09-10

    LIGHT (lymphotoxin-related inducible ligand that competes with herpes simplex virus (HSV) glycoprotein D for herpesvirus entry mediator on T cells) is a member of the tumor necrosis factor (TNF) ligand superfamily, which plays important roles in inflammatory and immune responses. In the present study, the cDNAs of guinea pig (Cavia porcellus) LIGHT (designated as gpLIGHT) and its receptor herpes virus entry mediator (designated as gpHVEM) were amplified from spleen by reverse transcription polymerase chain reaction (RT-PCR). The ORFs of gpLIGHT and gpHVEM cover 726 and 861 bp, encoding predicted proteins with 241 and 286 aas, respectively. The three-dimensional (3D) structure, phylogenetic relationships, and characterization of both genes were also analyzed. We also generated a 3D model to verify interaction between the two proteins. Real-time quantitative PCR (qPCR) analysis revealed that both LIGHT and HVEM are constitutively expressed in guinea pig various tissues. A fusion protein SUMO (Small Ubiquitin-like Modifier)-gpsLIGHT (the soluble mature part of gpLIGHT) was efficiently expressed in Escherichia coli BL21 (DE3) and purified using metal chelate affinity chromatography (Ni-NTA). Laser scanning confocal microscopy (LSCM) showed that gpsLIGHT can bind its receptors on T cells. The LIGHT-HVEM signaling pathway plays an important role in the immune system, and our results might provide a platform for further research into the effects of LIGHT and HVEM.

  20. Analysis of normal and denerved laryngeal vocalization in guinea pigs (Cavia porcellus).

    PubMed

    Arch-Tirado, Emilio; Verduzco-Mendoza, Antonio; Taboada-Picazo, Verónica; Mota-Rojas, Daniel; Alonso-Spilsbury, Maria de Lourdes; Alfaro-Rodríguez, Alfonso

    2009-01-01

    Paralysis of the left vocal chord is frequent in human clinical practice; because of its anatomic similarity with human, the guinea pig might be a suitable biological model to analyze the phoniatric behavior in denerved animals. Forty newborn guinea pigs were used (20 control and 20 experimental); an incision was made in the ventricular region with the animals under general anesthesia over the middle line of the neck, until the lower left laryngeal nerve was found, the same was secured with alligator clips so that afterward a two-part dissection could be performed and the middle section could be removed (1cm) from the nerve endings (distal and proximal) before they were separated from the laryngeal structure. After recovery from surgery, vocal emissions were recorded in solitary for 6 minutes. The animals that had nerves removed showed an increase in fundamental vocalization frequency compared with the controls. F test was carried out (P=0.05) and no significant difference was found. When analyzing functional recovery, we found that the guinea pigs compensated vocal emissions at 20 days. With regard to the unilateral paralysis, the motility was frequently compensated by the healthy vocal chord, improving voice emission, and loss of air inhalation.

  1. Twenty-four–Hour Measurement of Intraocular Pressure in Guinea Pigs (Cavia porcellus)

    PubMed Central

    Ansari-Mood, Maneli; Mehdi-Rajaei, Seyed; Sadjadi, Reza; Selk-Ghaffari, Masoud; Williams, David L

    2016-01-01

    The objective of this study was to measure intraocular pressure (IOP) in intact, healthy guinea pigs (15 male, 15 female) every 2 h for a 24-h period. First, IOP was measured by using rebound tonometry (RBT). After a 1-min rest period, 0.5% proparacaine ophthalmic solution, a topical anesthetic, was applied to both eyes; 4 min after anesthetic instillation, IOP was measured by using applanation tonometry (APT). The IOP was lower during the light period (0700 to 1900) than during the dark phase (2000 to 0600). The lowest IOP by both RBT and APT (3.68 and 13.37 mm Hg, respectively) occurred at 0700, whereas maximal IOP occurred at 2300 for RBT (8.12 mm Hg) but at 2100 for APT (20.62 mm Hg). No significant differences in IOP between the left and right eyes or between RBT and APT were noted. In addition, daily variations in the IOP of guinea pigs seem to be independent of sex and body weight. The results of this study may be beneficial in the diagnosis and observation of glaucoma in guinea pigs. PMID:26817986

  2. Enriched Open Field Facilitates Exercise and Social Interaction in 2 Strains of Guinea Pigs (Cavia porcellus)

    PubMed Central

    Brewer, Jacob S; Bellinger, Seanceray A; Joshi, Prianca; Kleven, Gale A

    2014-01-01

    Current housing guidelines for laboratory rodents include recommendations for enrichment. Working with guinea pigs, we have developed an open-field enrichment paradigm that provides several aspects of this species’ natural environment. These naturalistic aspects include access to increased space for exploration, access to western timothy (Phleum pratense L.) hay, and grouping as a herd to facilitate social interaction. To determine the immediate effect on behavior from access to the enriched environment, female guinea pigs from 2 strains, IAF Hairless and NIH Hartley, were observed in both standard home cages and an open-field enriched environment. Subjects were housed with cagemates in pairs for the home-cage observation and were grouped as a herd when in the open-field arena. Behaviors were videorecorded for 1 h and then scored. Salivary cortisol levels were measured both prior to and immediately after behavioral observations. Analyses revealed higher levels of activity and social interaction in the open-field arena compared with the home cage, with no significant change in salivary cortisol levels. These results suggest that exposure to the open-field environment provide increased opportunities for exercise and social enrichment. Although additional studies are needed to determine long-term effects on experimental outcomes, the open-field configuration holds promise as a laboratory enrichment paradigm for guinea pigs. PMID:25199089

  3. Intraocular Pressure, Tear Production, and Ocular Echobiometry in Guinea Pigs (Cavia porcellus).

    PubMed

    Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Sadjadi, Reza; Azizi, Farzaneh

    2016-01-01

    The purpose of this study was to evaluate intraocular pressure (IOP) by means of rebound tonometry, to assess tear production by using the endodontic absorbent paper point tear test (EAPTT) and phenol red thread test (PRTT), and to determine the effects of time of day on IOP and tear production in guinea pigs. The study population comprised 24 healthy adult guinea pigs (12 male, 12 female; 48 eyes) of different breeds and ranging in age from 12 to 15 mo. IOP and tear production were measured at 3 time points (0700, 1500, and 2300) during a 24-h period. Overall values (mean ± 1 SD) were: IOP, 6.81 ± 1.41 mm Hg (range, 4.83 to 8.50); PRTT, 14.33 ± 1.35 mm (range, 12.50 to 16.83); and EAPTT, 8.54 ± 1.08 mm (range, 7.17 to 10.0 mm). In addition, ultrasound biometry was performed by using a B-mode system with linear 8-MHz transducer. This study reports reference values for IOP and tear production in guinea pigs.

  4. Intraocular Pressure, Tear Production, and Ocular Echobiometry in Guinea Pigs (Cavia porcellus)

    PubMed Central

    Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Sadjadi, Reza; Azizi, Farzaneh

    2016-01-01

    The purpose of this study was to evaluate intraocular pressure (IOP) by means of rebound tonometry, to assess tear production by using the endodontic absorbent paper point tear test (EAPTT) and phenol red thread test (PRTT), and to determine the effects of time of day on IOP and tear production in guinea pigs. The study population comprised 24 healthy adult guinea pigs (12 male, 12 female; 48 eyes) of different breeds and ranging in age from 12 to 15 mo. IOP and tear production were measured at 3 time points (0700, 1500, and 2300) during a 24-h period. Overall values (mean ± 1 SD) were: IOP, 6.81 ± 1.41 mm Hg (range, 4.83 to 8.50); PRTT, 14.33 ± 1.35 mm (range, 12.50 to 16.83); and EAPTT, 8.54 ± 1.08 mm (range, 7.17 to 10.0 mm). In addition, ultrasound biometry was performed by using a B-mode system with linear 8-MHz transducer. This study reports reference values for IOP and tear production in guinea pigs. PMID:27423156

  5. Hematology and clinical chemistry values of normal and euthymic hairless adult male Dunkin-Hartley guinea pigs (Cavia porcellus).

    PubMed

    Waner, Trevor; Avidar, Yaakov; Peh, Hao-Chang; Zass, Rosa; Bogin, Eitan

    1996-01-01

    Hematology and serum chemistry measurements were performed on blood specimens from 12 male Dunkin-Hartley hairless guinea pigs Crl:IAF(HA)BR and 10 haired Dunkin-Hartley male guinea pigs Crl:(HA)BR. Significantly higher activities of alanine aminotransferase, aspartate aminotransferase, amylase, and creatine kinase were observed in the hairless guinea pigs as compared to the haired strain. Alkaline phosphatase activity was found to be lower in the hairless guinea pig. The hairless guinea pigs were found to have serum urea concentrations approximately 46% higher than the normal guinea pig strain. The erythrocytic mean cell volume of the hairless strain was found to be smaller, with a greater hemoglobin content. Hairless guinea pigs were found to have approximately 40% fewer leukocytes with a reversed lymphocyte:neutrophil ratio compared to the haired guinea pigs which had much higher lymphocyte counts.

  6. An outbreak of Trixacarus caviae infestation in guinea pigs at an animal petting facility and an evaluation of the safety and suitable dose of selamectin treatment.

    PubMed

    Honda, M; Namikawa, K; Hirata, H; Neo, S; Maruo, T; Lynch, J; Chida, A; Morita, T

    2011-08-01

    In June 2009, 27 guinea pigs kept at an animal petting facility at a zoo in Kanagawa Prefecture, Japan, were observed to scratch intensely, weaken, and develop lesions. Three sarcoptiform mites were found in skin scrapings taken from affected areas of 2 guinea pigs, and they were identified as Trixacarus caviae by morphological examination. This result confirmed the presence of T. caviae in Japan. For treatment, doses of 13.6-18.75 mg/head of selamectin were administered in a topical preparation applied to a single spot on the skin on the back of the neck, and no side effects were observed. In April 2010, a second outbreak of mange occurred at the zoo, and, following investigation, 2 mite eggs were observed. It was, therefore, thought probable that the mites had survived during the winter within nonclinical carriers. Accordingly, doses of 5.0-7.5 mg/head of selamectin were applied on days 0 and 28, after which clinical symptoms disappeared and general condition improved. This dose of selamectin was thus shown to be a suitable and economical treatment for guinea pigs infested with the mites. Because the mite is not always easily observed in infested guinea pigs and the potential for human infestation exists, clinicians should not hesitate to treat when the clinical presentation suggests infestation, particularly in a setting such as an animal petting facility, where large numbers of children and adults have direct contact with the animals.

  7. Control of the estrous cycle in guinea-pig (Cavia porcellus).

    PubMed

    Grégoire, A; Allard, A; Huamán, E; León, S; Silva, R M; Buff, S; Berard, M; Joly, T

    2012-09-01

    The aim of this work was to look for a simple method to obtain synchronized ovulation in guinea pigs under farming conditions while respecting animal welfare. The luteolytic activity of three different prostaglandins F2alpha (PGF2α) analogs (D-cloprostenol, D,L-cloprostenol and luprostiol) and a daily treatment with oral progestagen (altrenogest) was tested successively at different stages of the estrous cycle on the same group of females during a period of 8 mo. The estrous cycle length was not modified by the administration of PGF2α analogs, whatever the stage of the estrous cycle when the treatment was initiated. Our results led us to reject the use of PGF2α analog to induce practical synchronization of the estrus in this species. In females (n = 29), given 15 days with altrenogest (0.1 mL po once a day), ovulation occurred 4.43 ± 0.13 days after the end of the treatment. Altrenogest treatment was followed by mating. No negative impacts of the treatment on the pregnancy rates, delivery rates and litter sizes were observed. This standard method of guinea-pig estrus synchronization is less stressful for the animals compared to techniques using progesterone tubing.

  8. Genetic diversity and population structure of the Guinea pig (Cavia porcellus, Rodentia, Caviidae) in Colombia

    PubMed Central

    Burgos-Paz, William; Cerón-Muñoz, Mario; Solarte-Portilla, Carlos

    2011-01-01

    The aim was to establish the genetic diversity and population structure of three guinea pig lines, from seven production zones located in Nariño, southwest Colombia. A total of 384 individuals were genotyped with six microsatellite markers. The measurement of intrapopulation diversity revealed allelic richness ranging from 3.0 to 6.56, and observed heterozygosity (Ho) from 0.33 to 0.60, with a deficit in heterozygous individuals. Although statistically significant (p < 0.05), genetic differentiation between population pairs was found to be low. Genetic distance, as well as clustering of guinea-pig lines and populations, coincided with the historical and geographical distribution of the populations. Likewise, high genetic identity between improved and native lines was established. An analysis of group probabilistic assignment revealed that each line should not be considered as a genetically homogeneous group. The findings corroborate the absorption of native genetic material into the improved line introduced into Colombia from Peru. It is necessary to establish conservation programs for native-line individuals in Nariño, and control genealogical and production records in order to reduce the inbreeding values in the populations. PMID:22215979

  9. Morphological and immunohistochemical characterization of spontaneous mammary gland tumors in the guinea pig (Cavia porcellus).

    PubMed

    Suárez-Bonnet, A; Martín de Las Mulas, J; Millán, M Y; Herráez, P; Rodríguez, F; Espinosa de los Monteros, A

    2010-03-01

    Ten spontaneous mammary gland tumors affecting guinea pigs (GP) were analyzed histologically and immunohistochemically. Histologically, 3 were benign (2 simple adenomas and 1 benign mixed tumor) and 7 were malignant (1 simple solid carcinoma and 6 simple tubulopapillary carcinomas). Immunohistochemical data revealed the glandular immunoprofile of all the tumors and suggested their ductal origin on the basis of cytokeratin 20 expression. Interestingly, cytokeratin 7 was detected in basal/myoepithelial cells. Further, all tumors were positive for type alpha estrogen and progesterone receptors, suggesting a role for steroid hormones in the development of these neoplasias in GP. This article describes the morphological and immunohistochemical features of the normal mammary gland and spontaneous mammary gland tumors in GP.

  10. A model of latent adenovirus 5 infection in the guinea pig (Cavia porcellus).

    PubMed

    Vitalis, T Z; Keicho, N; Itabashi, S; Hayashi, S; Hogg, J C

    1996-03-01

    A model of adenovirus 5 (Ad5) infection was developed in guinea pigs to begin to study its role in the pathogenesis of peripheral lung inflammation. Forty animals were inoculated intranasally with 10(7.0) pfu of Ad5/animal, and 15 animals inoculated with sterile culture media served as controls. Viral titres were 10(4.4), 10(6.1), 10(5.2), and 10(2.9) pfu/animal, on days 1, 3, 4, and 7 after infection, respectively. In situ hybridization to viral DNA and immunocytochemistry for Ad5 E1A protein localized the virus to airway and alveolar epithelial cells. Histologic examination showed an extensive inflammatory cell infiltration around the airways, with epithelial necrosis and an alveolar exudate that caused localized alveolar collapse in the infected areas. Immunocytochemistry identified the cells in the infiltrate as cytotoxic T cells. Although all animals 20 and 47 days after infection had seroconverted to Ad5, virus was not detected in these groups either by viral plaque assay or in situ hybridization. Ad5 E1A DNA was detected by polymerase chain reaction in five of six animals 20 days after infection and in five of five animals 47 days after infection. In these same animals, E1A protein was detected 20 days after infection in two and 47 days after infection in one while persistent bronchiolitis was observed in four and three animals 20 and 47 days after infection, respectively. These results demonstrate that the guinea pig provides a useful model to study the role of Ad5 infection in chronic airway inflammation.

  11. The acoustical cues to sound location in the guinea pig (Cavia porcellus).

    PubMed

    Greene, Nathaniel T; Anbuhl, Kelsey L; Williams, Whitney; Tollin, Daniel J

    2014-10-01

    There are three main acoustical cues to sound location, each attributable to space- and frequency-dependent filtering of the propagating sound waves by the outer ears, head, and torso: Interaural differences in time (ITD) and level (ILD) as well as monaural spectral shape cues. While the guinea pig has been a common model for studying the anatomy, physiology, and behavior of binaural and spatial hearing, extensive measurements of their available acoustical cues are lacking. Here, these cues were determined from directional transfer functions (DTFs), the directional components of the head-related transfer functions, for 11 adult guinea pigs. In the frontal hemisphere, monaural spectral notches were present for frequencies from ∼10 to 20 kHz; in general, the notch frequency increased with increasing sound source elevation and in azimuth toward the contralateral ear. The maximum ITDs calculated from low-pass filtered (2 kHz cutoff frequency) DTFs were ∼250 μs, whereas the maximum ITD measured with low-frequency tone pips was over 320 μs. A spherical head model underestimates ITD magnitude under normal conditions, but closely approximates values when the pinnae were removed. Interaural level differences (ILDs) strongly depended on location and frequency; maximum ILDs were <10 dB for frequencies <4 kHz and were as large as 40 dB for frequencies >10 kHz. Removal of the pinna reduced the depth and sharpness of spectral notches, altered the acoustical axis, and reduced the acoustical gain, ITDs, and ILDs; however, spectral shape features and acoustical gain were not completely eliminated, suggesting a substantial contribution of the head and torso in altering the sounds present at the tympanic membrane.

  12. The acoustical cues to sound location in the Guinea pig (cavia porcellus)

    PubMed Central

    Greene, Nathanial T; Anbuhl, Kelsey L; Williams, Whitney; Tollin, Daniel J.

    2014-01-01

    There are three main acoustical cues to sound location, each attributable to space-and frequency-dependent filtering of the propagating sound waves by the outer ears, head, and torso: Interaural differences in time (ITD) and level (ILD) as well as monaural spectral shape cues. While the guinea pig has been a common model for studying the anatomy, physiology, and behavior of binaural and spatial hearing, extensive measurements of their available acoustical cues are lacking. Here, these cues were determined from directional transfer functions (DTFs), the directional components of the head-related transfer functions, for eleven adult guinea pigs. In the frontal hemisphere, monaural spectral notches were present for frequencies from ~10 to 20 kHz; in general, the notch frequency increased with increasing sound source elevation and in azimuth toward the contralateral ear. The maximum ITDs calculated from low-pass filtered (2 kHz cutoff frequency) DTFs were ~250 µs, whereas the maximum ITD measured with low frequency tone pips was over 320 µs. A spherical head model underestimates ITD magnitude under normal conditions, but closely approximates values when the pinnae were removed. Interaural level differences (ILDs) strongly depended on location and frequency; maximum ILDs were < 10 dB for frequencies < 4 kHz and were as large as 40 dB for frequencies > 10 kHz. Removal of the pinna reduced the depth and sharpness of spectral notches, altered the acoustical axis, and reduced the acoustical gain, ITDs, and ILDs; however, spectral shape features and acoustical gain were not completely eliminated, suggesting a substantial contribution of the head and torso in altering the sounds present at the tympanic membrane. PMID:25051197

  13. Motivated behaviors elicited from hypothalamus, midbrain, and pons of the guinea pig (Cavia porcellus).

    PubMed

    Martin, J R

    1976-11-01

    Eating, drinking, biting attack, male mating behavior, and gnawing were elicited by electrical stimulation through electrodes located predominantly in a region extending from the preoptic area through the lateral hypothalamus into the ventral midbrain. Escape and digging were elicited from a parallel but more medial region that overlapped the lateral zone only in the preoptic-anterior hypothalamic area. Several differentiable vocalizations were produced from sites distributed through most, although not all, areas explored. Sites yielding painlike responses were located principally in the vicinity of the presumed pain pathway traced after anterolateral cordotomy in other species. Reward was obtained from widespread sites that were generally congruent with catecholaminergic systems as described in the rat. Although there was considerable overlap of the effective zones for many responses, their underlying mechanisms were differentiated anatomically by localized differences in their distribution or functionally by the elicitation of pure responses from some electrodes. Response mechanisms localized in the brain stem of the guinea pig generally resembled those in the rat, although there were differences in details, especially in the posterior midbrain and pons.

  14. The developing and restructuring superior cervical ganglion of guinea pigs (Cavia porcellus var. albina).

    PubMed

    Toscano, Cauê Pereira; de Melo, Mariana Pereira; Matera, Júlia Maria; Loesch, Andrzej; Ribeiro, Antonio Augusto Coppi Maciel

    2009-06-01

    Post-natal development comprises both maturation (from newborn to adult) and ageing (from adult to senility) and, during this phase, several adaptive mechanisms occur in sympathetic ganglia, albeit they are not fully understood. Therefore, the present study aimed at detecting whether post-natal development would exert any effect on the size and number of a guinea pig's superior cervical ganglion (SCG) neurons. Twenty right SCGs from male subjects were used at four ages, i.e. newborn (7 days), young (30 days), adult (7 months) and old animals (50 months). Using design-based stereological methods the volume of ganglion and the total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal volume of mononucleate and binucleate neurons was estimated using the vertical nucleator. The main findings of this study were a combination of post-natal-dependent increases and decreases in some variables: (i) 27% increase in ganglion volume, (ii) 24% and 43% decreases in the total number of mono and binucleate neurons, respectively, and (iii) 27.5% and 40% decreases in the mean perikaryal volume of mono and binucleate neurons, respectively. Despite the fall in neuron numbers found here, post-natal development is not only associated with neuron loss, but also embraces other structural adaptive mechanisms, which are discussed in this paper.

  15. An Investigation of the Effects of Maternal Separation and Novelty on Central Mechanisms Mediating Pituitary-Adrenal Activity in Infant Guinea Pigs (Cavia porcellus)

    PubMed Central

    Maken, Deborah S.; Weinberg, Joanne; Cool, David R.; Hennessy, Michael B.

    2016-01-01

    In mammalian species in which the young exhibit a strong filial attachment (e.g., monkeys, guinea pigs), numerous studies have shown that even brief separation from the attachment figure potently elevates circulating concentrations of glucocorticoids and adrenocorticotropic hormone (ACTH). However, effects of separation on central regulation of this stress response are not known. Therefore, we investigated central mechanisms mediating pituitary-adrenal activation during maternal separation and novelty exposure in guinea pig (Cavia porcellus) pups. Corticotropin-releasing factor (CRF) mRNA expression in the hypothalamic paraventricular nucleus (PVN), and plasma cortisol and ACTH levels, were elevated only during separation in a novel environment. C-Fos activity was elevated in the medial amygdala (MeA) and reduced in the bed nucleus of the stria terminalis (BNST) during novelty exposure, regardless of separation. On the other hand, c-Fos activity was elevated in the PVN during separation, regardless of novelty exposure. These results demonstrate independent and combined effects of separation and novelty in regions of the guinea pig CNS that regulate pituitary-adrenal activity. Moreover, they suggest that a pathway from MeA to BNST to PVN mediates responses to novelty in the guinea pig pup, as in the adult rat, though inputs from other cell populations appear required to fully account for the HPA activity observed here. PMID:21038937

  16. Mandibular movement and muscle activity during mastication in the guinea pig (Cavia porcellus).

    PubMed

    Byrd, K E

    1981-11-01

    Optoelectronic analysis of mandibular movement and electromyography (EMG) of masticatory muscles in Cavia porcellus indicate bilateral, unilateral, and gnawing cycles. During bilateral and unilateral cycles, the mandibular tip moves forward, lateral, and down during the lingual phase of the power stroke to bring the teeth into occlusion. EMG activity is generally asymmetric, with the exception of activity of the temporalis muscle during bilateral cycles. During gnawing cycles, the mandible moves in an anteroposterior direction that is opposite that during bilateral and unilateral chew cycles. Bilateral and unilateral cycles of pellets were significantly longer than carrot. With the exception of the width of bilateral cycles, the magnitude of cycle width, length, and height during the mastication of carrots was greater than that during the mastication of pellets. Significant differences exist between EMG durations during mastication of pellets and carrots. The lateral pterygoid displays continuous activity during gnawing cycles. Significant differences also exist in the duration of EMG activity between the working and balancing side during all three cycle types. High level of activity of balancing side temporalis and anterior belly of digastric (ABD) during bilateral cycles occurs during rotation and depression of the mandible during the power stroke. The temporalis apparently provides a "braking" or compensatory role during closing and power strokes. Differences between Cavia masticatory patterns and those shown by Rattus and Mesocricetus are apparently due to differences in dental morphology, occlusal relationships, and, possibly, the poorly developed temporalis in Cavia. The large number and wide diversity of rodent groups afford students of mammalian mastication an opportunity to investigate and compare different masticatory specializations.

  17. Intake, selection, digesta retention, digestion and gut fill of two coprophageous species, rabbits (Oryctolagus cuniculus) and guinea pigs (Cavia porcellus), on a hay-only diet.

    PubMed

    Franz, R; Kreuzer, M; Hummel, J; Hatt, J-M; Clauss, M

    2011-10-01

    A colonic separation mechanism (CSM) is the prerequisite for the digestive strategy of coprophagy. Two different CSM are known in small herbivores, the 'wash-back' CSM of lagomorphs and the 'mucous-trap' CSM of rodents. Differences between these groups in their digestive pattern when fed exclusively hay were investigated in six rabbits (Oryctolagus cuniculus) and six guinea pigs (Cavia porcellus). Intake, digestibility (by total faecal collection), solute and particle mean retention times (MRT, using Co-EDTA and Cr-mordanted fibres) were measured. Rabbits selected less fibrous parts of the hay than guinea pigs, leaving orts with higher content of neutral detergent fibre [NDF; 721 ± 21 vs. 642 ± 31 g/kg dry matter (DM) in guinea pigs]. They also expressed a lower NDF digestibility (0.44 ± 0.10 vs. 0.55 ± 0.05 of total), a similar particle MRT (15 ± 3 vs. 18 ± 6 h), a longer solute MRT (51 ± 9 vs. 16 ± 4 h), and a lower calculated dry matter gut fill (19.6 ± 4.7 vs. 29.7 ± 4.1 g DM/kg body mass) than guinea pigs (p < 0.05 for each variable). These results support the assumption that the 'wash-back' CSM, exhibited in the rabbits, is more efficient in extracting bacterial matter from the colonic digesta plug than the 'mucous-trap' CSM found in the guinea pigs. Related to metabolic body mass, rabbits therefore need a less capacious colon for their CSM where a more efficient bacteria wash-out is reflected in the lower fibre digestibility. A lighter digestive tract could contribute to a peculiarity of lagomorphs: their ability to run faster than other similar-sized mammals. © 2010 Blackwell Verlag GmbH.

  18. An Investigation into the Relationship between Owner Knowledge, Diet, and Dental Disease in Guinea Pigs (Cavia porcellus)

    PubMed Central

    Norman, Rosemary; Wills, Alison P.

    2016-01-01

    Simple Summary Dental disease is a serious problem in small mammals, with cases in rabbits well documented. Guinea pigs also suffer from this condition, yet the literature investigating the underlying causes in guinea pigs is limited. Owners of guinea pigs were surveyed to investigate what they fed their animals. It was discovered that there was no relationship between the overall diet of the animals and whether or not they had been diagnosed with dental disease or displayed clinical signs of the disease. However, the environment was important, with animals that had access to the outside, including the use of runs on both concrete and grass, less likely to display clinical signs of disease. Some of the clinical signs of dental disease in guinea pigs, including difficulty eating, were related to dental problems. These findings are important, as many guinea pigs may not have continuous access to the outdoors. Dental disease is a serious welfare concern, as many owners may not pick up on the clinical signs, leaving animals susceptible to pain, dysphagia, malnutrition, and secondary infection. It is important that owners are aware of key clinical signs, particularly in multi-animal households where monitoring food consumption may be challenging. Abstract Recent studies have highlighted a high prevalence of dental disease in domestic guinea pigs, yet the aetiology of this multi-factorial disease is still unclear. Factors that have been associated with dental disease include feeding a diet that is high in energy but low in fibre, feeding an insufficiently abrasive diet, a lack of dietary calcium, and genetics. As many of these factors relate to the husbandry requirements of guinea pigs, owner awareness of dietary requirements is of the utmost importance. An online questionnaire was created based on previous research into the husbandry and feeding of rabbits. Guinea pig owners were asked to answer questions on the clinical history of their animals and their diet and

  19. The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti).

    PubMed

    Simões, Luciana S; Sasahara, Tais H C; Favaron, Phelipe O; Marques, Ricardo; Oliveira, Moacir F DE; Machado, Márcia R F; Miglino, Maria Angelica

    2017-01-01

    The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.

  20. Effect of a supplementation of Euphorbia heterophylla on nutritional meat quality of Guinea pig (Cavia porcellus L.).

    PubMed

    Kouakou, N'Goran David Vincent; Grongnet, Jean-François; Assidjo, Nogbou Emmanuel; Thys, Eric; Marnet, Pierre-Guy; Catheline, Daniel; Legrand, Philippe; Kouba, Maryline

    2013-04-01

    The aim of the present work was to study the effect of dietary supplementation of Euphorbia heterophylla on the quality of the Guinea pig meat. Forty guinea pigs were divided into two groups fed ad libitum during 46 days a Panicum maximum diet (Panicum diet) or a mixed diet (75% Panicum maximum+25% Euphorbia heterophylla) (Paneuphorbia diet) to compare their effects on performances and on the composition of guinea pig tissues and carcass. Daily weight gain, liver weight, carcass yield, and the lipid content of both the carcass and the perirenal fat were significantly increased by the Paneuphorbia diet. Feeding Paneuphorbia diet increased (P<0.05) the n-3 PUFA content in perirenal fat, muscle, liver and in the carcass and decreased (P<0.05) the n-6/n-3 ratios in all these tissues and the carcass. In conclusion, this study shows that Euphorbia heterophylla is a source of n-3 fatty acids which can improve significantly the n-3 PUFA content of Guinea pig meat and carcass. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. An Investigation into the Relationship between Owner Knowledge, Diet, and Dental Disease in Guinea Pigs (Cavia porcellus).

    PubMed

    Norman, Rosemary; Wills, Alison P

    2016-11-14

    Recent studies have highlighted a high prevalence of dental disease in domestic guinea pigs, yet the aetiology of this multi-factorial disease is still unclear. Factors that have been associated with dental disease include feeding a diet that is high in energy but low in fibre, feeding an insufficiently abrasive diet, a lack of dietary calcium, and genetics. As many of these factors relate to the husbandry requirements of guinea pigs, owner awareness of dietary requirements is of the utmost importance. An online questionnaire was created based on previous research into the husbandry and feeding of rabbits. Guinea pig owners were asked to answer questions on the clinical history of their animals and their diet and management. In total, 150 surveys were completed for 344 guinea pigs, where owners of multiple animals could complete the survey for individuals. According to the owners, 6.7% of guinea pigs had been clinically diagnosed with dental disease, but 16.6% had signs consistent with dental disease. The specific clinical signs of having difficulty eating (Exp(B) = 33.927, Nagelkerke R ² = 0.301, p < 0.05) and producing fewer or smaller faecal droppings (Exp(B) = 13.733, Nagelkerke R ² = 0.149, p < 0.05) were predictive for the presence of dental disease. Having access to an outside environment, including the use of runs on both concrete and grass, was significantly related to not displaying clinical signs of dental disease (Exp(B) = 1.894, Nagelkerke R ² = 0.021, p < 0.05). There was no significant relationship between owner knowledge, guinea pig diet, and dental disease in the study population. This study highlights the importance of access to the outdoors for the health and welfare of guinea pigs in addition to the need for owners to be alert to key clinical signs. A relationship between diet and dental disease was not identified in this study; however, the underlying aetiological causes of this condition require further investigation.

  2. Pharmacokinetics and Paw Withdrawal Pressure in Female Guinea Pigs (Cavia porcellus) Treated with Sustained-Release Buprenorphine and Buprenorphine Hydrochloride.

    PubMed

    Smith, Brian J; Wegenast, Daniel J; Hansen, Ryan J; Hess, Ann M; Kendall, Lon V

    2016-11-01

    Providing appropriate analgesia is essential in minimizing pain and maintaining optimal animal care and welfare in laboratory animals. Guinea pigs are common animal models in biomedical research, often requiring analgesic support. Here we evaluated the pharmacokinetics and efficacy of a sustained-release formulation of buprenorphine (Bup-SR) in this species. Guinea pigs (n = 7 each group) received either Bup-HCl (0.05 mg/kg BID for 3 d) or Bup-SR (0.3 mg/kg once). Plasma collection and measurement of paw-withdrawal pressure (PWP) was conducted at 0, 1, 3, 6, 12, 26, 48, and 72 h after treatment. Plasma levels of Bup-HCl peaked at 2331 pg/mL at 1 h after administration and declined to 165 pg/mL by 12 h. Plasma concentrations of Bup-SR peaked at 1344 pg/mL at 26 h after administration and declined to 429 pg/mL by 48 h. The PWP of the Bup-HCltreated guinea pigs peaked at 674 g at 1 h and declined to 402 g at 6 h, whereas that of Bup-SRtreated guinea pigs at 1 h was 361 g, 555 g at 6 h (significantly higher than that after Bup-HCl), and peaked at 680 g at 12 h. The PWP of both treatments was similar from 24 to 72 h and ranged from 348 to 450 g. The plasma concentration and PWP showed good correlation. These results suggest that Bup-SR provides consistent analgesia equivalent to that of Bup-HCl for a prolonged period of time and that Bup-SR is an alternative method of analgesia in guinea pigs.

  3. Evaluation of Using Behavioural Changes to Assess Post-Operative Pain in the Guinea Pig (Cavia porcellus)

    PubMed Central

    Ellen, Yvette; Flecknell, Paul; Leach, Matt

    2016-01-01

    To manage pain effectively in people and animals, it is essential to recognise when pain is present and to assess its intensity. Currently there is very little information regarding the signs of post-surgical pain or its management in guinea pigs. Studies from other rodent species indicate that behaviour-based scoring systems can be used successfully to detect pain and evaluate analgesic efficacy. This preliminary study aimed to establish whether behaviour-based scoring systems could be developed to assess post-surgical pain in guinea pigs. This prospective, randomised, placebo-controlled study used 16 guinea pigs, and evaluated changes in behaviour following either anaesthesia alone or anaesthesia and orchiectomy. Behaviour was assessed using a combination of manual and automated scoring of remotely obtained video footage. A small number of behaviours were identified that appeared to have high specificity for pain caused by orchiectomy. However, the behaviours were displayed infrequently. The most common was a change in posture from standing to recumbency, sometimes with one hind leg extended either to the side or behind the body. A composite behaviour score incorporating these abnormal behaviours differentiated between the effects of surgery and anaesthesia alone (p<0.0001), and between animals that received analgesia post-operatively compared to an untreated group (p<0.0001). Although behavioural changes occurred in these guinea pigs after orchiectomy, the changes were relatively subtle and the individual specific pain-related behaviours occurred infrequently. However, it may prove possible to develop a behaviour-based scoring system for routine use in this species using a combination of pain-related behaviours. PMID:27583446

  4. Isolation and culture of highly enriched populations of Leydig cells from guinea-pig (Cavia porcellus) testes.

    PubMed

    Kukucka, M A; Misra, H P

    1994-01-01

    Leydig cells were isolated from adult male guinea-pig testes using a multi-step procedure involving enzymatic dissociation and Percoll-gradient centrifugation. The following description is the first account of a successful isolation of adolescent guinea-pig Leydig cells. The enriched Leydig-cell preparation routinely isolated from six intact testicles yielded approximately 5.0 x 10(6) +/- 0.7 x 10(6) (+/- SEM) Leydig cells with a viability of 98.0 +/- 0.4% as determined using the trypan-blue exclusion method. The purity of the isolated cell population as assessed by 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) staining averaged 82.5 +/- 0.8%. Under light microscopy, guinea-pig Leydig cells were polyhedral in shape with a large prominent nucleus and a distinct nucleolus. The acidophilic cytoplasm contained numerous lipid-filled vesicles. Ultrastructurally, guinea-pig Leydig cells displayed an eccentrically located ovoid nucleus with dark-staining peripheral heterochromatin. Large quantities of mitochondria, smooth endoplasmic reticulum and particulate-laden lipid droplets were also evident. The steroidogenic potential of the isolated Leydig cells was verified using a maximally stimulating dose of ovine LH (100 ng ml-1) and human CG (200 mIU ml-1). Leydig cells incubated in a shaking (120 cycles min-1) water bath for 3 h at 37 degrees C in capped polypropylene microcentrifuge tubes produced 233 +/- 21 ng and 223 +/- 18 ng testosterone per 1 x 10(6) cells when maximally stimulated with oLH or hCG, respectively. The inclusion of low (1-5 microM) levels of sodium ascorbate during culture enhanced significantly Leydig-cell viability vs. control values.

  5. Interactions of chromatic and lens-induced defocus during visual control of eye growth in guinea pigs (Cavia porcellus).

    PubMed

    Jiang, Liqin; Zhang, Sen; Schaeffel, Frank; Xiong, Shibo; Zheng, Yibo; Zhou, Xiangtian; Lu, Fan; Qu, Jia

    2014-01-01

    It was recently demonstrated that chromaticity could affect eye growth and refractive development in guinea pigs but it remained unclear whether correction with spectacle lenses could balance these effects and how retinal responses change with different spectral compositions of light. Three illumination conditions were tested: blue, red and white light. Animals were raised without or with monocular spectacle lenses from three to seven weeks of age. Luminance electroretinograms (ERGs) were recorded to explore retinal responses with the different spectral compositions. In our special colony of pigmented guinea pigs, characterized by residual hyperopia, spontaneous myopia and poor emmetropization, red light induced early thinning of the choroid and relative myopia, compared to white light. Effects of red light could not be suppressed if positive spectacle lenses were worn. ERGs showed that red light failed to elicit robust retinal responses. Blue light inhibited axial eye growth, even when animals were reared with negative lenses. Intensity-matched blue and white light elicited similar a-waves but different b-waves, suggesting that the wavelength of light affects visual control of eye growth through different processing in the inner retina. We hypothesize that blue light might stimulate preferentially the ON pathway to inhibit myopia induced by negative lenses, at least in guinea pigs. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  6. Skin diseases in companion guinea pigs (Cavia porcellus): a retrospective study of 293 cases seen at the Veterinary Medical Teaching Hospital, University of California at Davis (1990-2015).

    PubMed

    White, Stephen D; Guzman, David Sanchez-Migallon; Paul-Murphy, Joanne; Hawkins, Michelle G

    2016-10-01

    Guinea pigs (Cavia porcellus) are popular companion animals with reported skin diseases, but most reports are accessed from textbooks or review articles. To document skin diseases and their prevalence in companion guinea pigs in northern California, USA, and to investigate predilections for the most common conditions over a 25 year period. Two hundred and ninety three guinea pigs from the hospital population met inclusion criteria. A retrospective study was performed by searching computerized medical records seen at the Veterinary Medical Teaching Hospital (VMTH), School of Veterinary Medicine, University of California from 1 January 1990 to 31 July 2015 using key words relevant to dermatology. Of the 580 guinea pigs seen at the VMTH, 50% (293) had skin disease. Of the 293 cases, 154 (52%) presented for nondermatological reasons. Guinea pigs with skin disease were significantly older than those without skin disease (P = 0.0002); females with skin disease were more likely to have cystic ovaries (P = 0.0203), although these were not always associated with alopecia. Pododermatitis and infestation with Trixacarus caviae or lice were the most common skin diseases. Ivermectin or selamectin was used for ectoparasite treatment. Abscesses unassociated with pododermatitis were the most common nodules. Benign follicular tumours were the most common neoplasm. Despite the frequent mention of dermatophytosis in the veterinary literature, only two cases of Trichophyton mentagrophytes were diagnosed. Cutaneous conditions in companion guinea pigs in the USA are common. Clinicians should include a dermatological examination when examining these rodents regardless of the reason for presentation. © 2016 ESVD and ACVD.

  7. Morphometric evaluation of wound healing in burns treated with Ulmo (Eucryphia cordifolia) honey alone and supplemented with ascorbic acid in guinea pig (Cavia porcellus).

    PubMed

    Schencke, Carolina; Vasconcellos, Adriana; Sandoval, Cristian; Torres, Paulina; Acevedo, Francisca; Del Sol, Mariano

    2016-01-01

    In the context of the search for cost-efficient treatments, Ulmo (Eurcyphia cordifolia) honey is an excellent alternative for treating burn wounds and could have a profound medical, social, and economic impact. Ascorbic acid is an enzymatic co-factor necessary for the synthesis of collagen and the proliferation of fibroblasts and has been proposed as a coadjuvant to strengthen the healing effects of honey. The aim of this work was to evaluate by morphometric studies the healing wounds caused by burns treated with Ulmo honey alone and supplemented with ascorbic acid in guinea pig (Cavia porcellus). Fifteen guinea pigs were used and divided randomly into three groups: positive control (C+), experimental with unsupplemented honey (H), and experimental with supplemented honey (SH). A uniform deep burn covering 1 cm(2) of the back skin was performed. The following indices were calculated for the morphometric study: superficial contraction index of the wound, deep contraction index of the wound, wound severity index, global healing index, global contraction index, and dermal proliferation area. The superficial contraction index of the wound, global healing index, global contraction, and dermal proliferation area values of the experimental with supplemented honey group were higher than the other groups (P < 0.05). According to these results, the combination of honey with an antioxidant (ascorbic acid) promotes an appropriate action to support the healing effect. This study showed that by supplementing the Ulmo honey with ascorbic acid, the healing and contraction effects can be strengthened in burn wounds compared to unsupplemented honey. These results were proof of the synergy between honey and ascorbic acid in healing burn wounds.

  8. Fetal Growth Restriction Induces Heterogeneous Effects on Vascular Biomechanical and Functional Properties in Guinea Pigs (Cavia porcellus).

    PubMed

    Cañas, Daniel; Herrera, Emilio A; García-Herrera, Claudio; Celentano, Diego; Krause, Bernardo J

    2017-01-01

    Aim: Fetal growth restriction (FGR) is associated with a variety of cardiometabolic diseases in adulthood which could involve remodeling processes of the vascular walls that could start in the fetal period. However, there is no consensus whether this remodeling affects in a similar way the whole vascular system. We aimed to determine the effects of FGR on the vasoactive and biomechanical properties of umbilical and systemic vessels in fetal guinea pigs. Methods: FGR was induced by implanting ameroid occluders at mid-gestation in uterine arteries of pregnant guinea pigs, whilst the control group was exposed to simulated surgery. At the term of gestation, systemic arteries (aorta, carotid and femoral) and umbilical vessels were isolated to determine ex vivo contractile and biomechanical responses (stretch-stress until rupture) on a wire myograph, as well as opening angle and residual stresses. Histological characteristics in tissue samples were measured by van Gieson staining. Results: Aorta and femoral arteries from FGR showed an increased in biomechanical markers of stiffness (p < 0.01), contractile capacity (p < 0.05) and relative media thickness (p < 0.01), but a reduced internal diameter (p < 0.001), compared with controls. There were no differences in the biomechanical properties of carotid and umbilical from control and FGR fetuses, but FGR umbilical arteries had a decreased contractile response to KCl (p < 0.05) along with a reduced relative media thickness (p < 0.05). Conclusion: Altogether, these changes in functional, mechanical and morphological properties suggest that FGR is associated with a heterogeneous pro-constrictive vascular remodeling affecting mainly the lower body fetal arteries. These effects would be set during a pathologic pregnancy in order to sustain the fetal blood redistribution in the FGR and may persist up to adulthood increasing the risk of a cardiovascular disease.

  9. Fetal Growth Restriction Induces Heterogeneous Effects on Vascular Biomechanical and Functional Properties in Guinea Pigs (Cavia porcellus)

    PubMed Central

    Cañas, Daniel; Herrera, Emilio A.; García-Herrera, Claudio; Celentano, Diego; Krause, Bernardo J.

    2017-01-01

    Aim: Fetal growth restriction (FGR) is associated with a variety of cardiometabolic diseases in adulthood which could involve remodeling processes of the vascular walls that could start in the fetal period. However, there is no consensus whether this remodeling affects in a similar way the whole vascular system. We aimed to determine the effects of FGR on the vasoactive and biomechanical properties of umbilical and systemic vessels in fetal guinea pigs. Methods: FGR was induced by implanting ameroid occluders at mid-gestation in uterine arteries of pregnant guinea pigs, whilst the control group was exposed to simulated surgery. At the term of gestation, systemic arteries (aorta, carotid and femoral) and umbilical vessels were isolated to determine ex vivo contractile and biomechanical responses (stretch-stress until rupture) on a wire myograph, as well as opening angle and residual stresses. Histological characteristics in tissue samples were measured by van Gieson staining. Results: Aorta and femoral arteries from FGR showed an increased in biomechanical markers of stiffness (p < 0.01), contractile capacity (p < 0.05) and relative media thickness (p < 0.01), but a reduced internal diameter (p < 0.001), compared with controls. There were no differences in the biomechanical properties of carotid and umbilical from control and FGR fetuses, but FGR umbilical arteries had a decreased contractile response to KCl (p < 0.05) along with a reduced relative media thickness (p < 0.05). Conclusion: Altogether, these changes in functional, mechanical and morphological properties suggest that FGR is associated with a heterogeneous pro-constrictive vascular remodeling affecting mainly the lower body fetal arteries. These effects would be set during a pathologic pregnancy in order to sustain the fetal blood redistribution in the FGR and may persist up to adulthood increasing the risk of a cardiovascular disease. PMID:28344561

  10. Angiogenic, hyperpermeability and vasodilator network in utero-placental units along pregnancy in the guinea-pig (Cavia porcellus)

    PubMed Central

    Valdés, Gloria; Erices, Rafaela; Chacón, Cecilia; Corthorn, Jenny

    2008-01-01

    Background The angiogenic and invasive properties of the cytotrophoblast are crucial to provide an adequate area for feto-maternal exchange. The present study aimed at identifying the localization of interrelated angiogenic, hyperpermeability and vasodilator factors in the feto-maternal interface in pregnant guinea-pigs. Methods Utero-placental units were collected from early to term pregnancy. VEGF, Flt-1, KDR, B2R and eNOS were analyzed by immunohistochemistry, and the intensity of the signals in placenta and syncytial streamers was digitally analysed. Flt1 and eNOS content of placental homogenates was determined by western blotting. Statistical analysis used one-way analysis of variance and Tukey's Multiple Comparison post-hoc test. Results In the subplacenta, placental interlobium and labyrinth VEGF, Flt-1, KDR, B2R and eNOS were expressed in all stages of pregnancy. Syncytial streamers in all stages of gestation, and cytotrophoblasts surrounding myometrial arteries in early and mid pregnancy – and replacing the smooth muscle at term – displayed immunoreactivity for VEGF, Flt-1, KDR, eNOS and B2R. In partly disrupted mesometrial arteries in late pregnancy cytotrophoblasts and endothelial cells expressed VEGF, Flt-1, KDR, B2R and eNOS. Sections incubated in absence of the first antibody, or in presence of rabbit IgG fraction and mouse IgG serum, yielded no staining. According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy. In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations. Western blots for eNOS and Flt-1 in

  11. [Classification of neurons in the visual cortex of the guinea pig (Cavia porcellus). A combined Golgi-Nissl study using deimpregnation technics].

    PubMed

    Werner, L; Hedlich, A; Koglin, A

    1986-01-01

    The aim of the investigation is the identification of neuronal types in the visual cortex of the guinea pig (Cavia porcellus) in Nissl preparations. In two rapid Golgi series (modified by Fairén et al. 1977) and nine Golgi-Kopsch series eleven neuronal types could be classified: 1. Neurons with long axonal main stems: Pyramidal cells (layers II-VI), pyramid-like cells (layers I, VI), spiny stellate cells (layer IV). 2. Neurons with locally distributed axons: large and small aspiny cells (layers II-VI), neuroglioform cells (layers I-VI), large sparsely spiny cells with ascending axons (Martinotti cells) (layers III-VI), small sparsely spiny cells with variable axons (layer IV), bipolar cells (layers II-VI), chandelier cells (layers II, III), double bouquet cells (layers II, III), and 3. a horizontal cell in layer I without an impregnated axon. To identify Nissl stained somata, Golgi impregnated neurons were deimpregnated. Now cytoplasmic and nuclear features can be compared. In order to get a survey about the variability of the somal features, we have deimpregnated 245 neurons on the whole using either gold chloride (Fairén et al. 1977) combined with the rapid Golgi method, modified by Fairén et al. (1977), or a diluted solution of ammonia (Braak and Braak 1982) combined with the Golgi-Kopsch method, nonembedded, in glycerol stored material and in celloidin embedded sections, resp. After deimpregnation several neuronal classes could be distinguished considering at first the width of the cytoplasm and the localization of the nucleus. There are Nissl stained somata with corresponding features: 1. Pyramidal cells, pyramid-like cells, and spiny stellate cells of the layer IV with relatively broad cytoplasm and bright, centrally localized nuclei. 2. Large aspiny cells which vary in somal sizes and shapes with very broad cytoplasm and bright, centrally or excentrally localized nuclei. 3. Small aspiny cells, some of the neuroglioform cells, and small sparsely spiny

  12. Expression of toll-like receptors 2 and 4 in subplacental trophoblasts from guinea pigs (Cavia porcellus) following infection with Campylobacter jejuni.

    PubMed

    Burrough, E R; DiVerde, K D; Sahin, O; Plummer, P J; Zhang, Q; Yaeger, M J

    2011-03-01

    Toll-like receptors 2 and 4 (TLR2 and TLR4) are well-characterized cell surface receptors that recognize specific pathogen-associated molecular patterns and play an important role in pathogen recognition and activation of the innate immune system. Variable expression of TLR2 and TLR4 has been described in trophoblasts from normal and diseased placentas; yet, there are limited data regarding trophoblast TLR expression in response to specific placental pathogens, and TLR expression in the guinea pig placenta has not been described. The guinea pig is an effective model for Campylobacter-induced abortion of small ruminants, and the authors have shown by immunohistochemistry that C jejuni localizes within syncytiotrophoblasts of the guinea pig subplacenta. The present study was designed to determine if the expression of either TLR2 or TLR4 would be affected in subplacental trophoblasts following infection with C jejuni. Immunohistochemistry for TLR2 and TLR4 was performed on placenta from guinea pigs that aborted following inoculation with C jejuni and from sham-inoculated controls. Quantitative assessment of TLR expression was performed, and mean immunoreactivity for TLR2 was significantly higher in subplacental trophoblasts from animals that aborted compared with uninfected controls (P = .0283), whereas TLR4 expression was not statistically different (P = .5909). These results suggest that abortion in guinea pigs following infection with C jejuni is associated with increased TLR2 expression in subplacental trophoblasts and may reveal a possible role for TLR2 in the pathogenesis of Campylobacter-induced abortion.

  13. Blood-feeding Behaviors of Anopheles stephensi But Not Phlebotomus papatasi are Influenced by Actively Warming Guinea Pigs (Cavia porcellus) Under General Anesthesia

    DTIC Science & Technology

    2015-01-01

    Scientific, Torrington, CT) was used as the warming device in this study. This device uses a warming pad that emits far-infrared radiation (FIR) to... injuries . Temperature was recorded every 5 min throughout the experiments. Feeding assay: Guinea pigs were divided into 2 groups (6 animals for mosquito...body and its radiation . Bull Entomol Res 42:535–541. Pinto MC, Campbell-Lendrum DH, Lozovei AL, Teodoro U, Davies CR. 2001. Phlebotomine sand fly

  14. Effects of animal or plant protein diets on cecal fermentation in guinea pigs (Cavia porcellus), rats (Rattus norvegicus) and chicks (Gallus gallus domesticus).

    PubMed

    Tsukahara, T; Ushida, K

    2000-10-01

    Monogastric herbivores such as the guinea pig depend on energy supply from enteric fermentation as short-chain fatty acids (SCFA) corresponding to 30-40% of their maintenance energy requirements. They evolved specific digestive system to adapt their indigenous microflora to plant polysaccharides fermentation. No information has been available about the adaptability of microbial fermentation in hindgut of the monogastric herbivorous to an animal protein diet. We investigated if the guinea pig can fully retrieve energy of an animal protein diet by hindgut fermentation compared with a plant protein diet. For comparison, we also studied two omnivores. End products of in vitro cecal fermentation (SCFA, ammonia and gases) were measured to judge how well an animal protein diet could be fermented. The animal protein diet resulted in the less intensive fermentation with increased feed intake and volume of cecal contents than the plant protein diet only in guinea pigs. This may be due to a limited capacity of the hindgut microflora to adapt to the substrate rich in animal protein. We also found that chick cecal contents produced methane at higher emission rate than ruminants.

  15. Pathogenic potential of a Costa Rican strain of 'Candidatus Rickettsia amblyommii' in guinea pigs (Cavia porcellus) and protective immunity against Rickettsia rickettsii.

    PubMed

    Rivas, Juan J; Moreira-Soto, Andrés; Alvarado, Gilberth; Taylor, Lizeth; Calderón-Arguedas, Olger; Hun, Laya; Corrales-Aguilar, Eugenia; Morales, Juan Alberto; Troyo, Adriana

    2015-09-01

    'Candidatus Rickettsia amblyommii' is a spotted fever group rickettsia that is not considered pathogenic, although there is serologic evidence of possible infection in animals and humans. The aim of this study was to evaluate the pathogenic potential of a Costa Rican strain of 'Candidatus R. amblyommii' in guinea pigs and determine its capacity to generate protective immunity against a subsequent infection with a local strain of Rickettsia rickettsii isolated from a human case. Six guinea pigs were inoculated with 'Candidatus R. amblyommii' strain 9-CC-3-1 and two controls with cell culture medium. Health status was evaluated, and necropsies were executed at days 2, 4, and 13. Blood and tissues were processed by PCR to detect the gltA gene, and end titers of anti-'Candidatus R. amblyommii' IgG were determined by indirect immunofluorescence. To evaluate protective immunity, another 5 guinea pigs were infected with 'Candidatus R. amblyommii' (IGPs). After 4 weeks, these 5 IGPs and 3 controls (CGPs) were inoculated with pathogenic R. rickettsii. Clinical signs and titers of anti-Rickettsia IgG were determined. IgG titers reached 1:512 at day 13 post-infection with 'Candidatus R. amblyommii'. On day 2 after inoculation, two guinea pigs had enlarged testicles and 'Candidatus R. amblyommii' DNA was detected in testicles. Histopathology confirmed piogranulomatous orchitis with perivascular inflammatory infiltrate in the epididymis. In the protective immunity assay, anti-Rickettsia IgG end titers after R. rickettsii infection were lower in IGPs than in CGPs. IGPs exhibited only transient fever, while CGP showed signs of severe disease and mortality. R. rickettsii was detected in testicles and blood of CGPs. Results show that the strain 9-CC-3-1 of 'Candidatus R. amblyommii' was able to generate pathology and an antibody response in guinea pigs. Moreover, its capacity to generate protective immunity against R. rickettsii may modulate the epidemiology and severity of Rocky

  16. Use of a Guinea Pig-Specific Transcriptome Array for Evaluation of Protective Immunity against Genital Chlamydial Infection following Intranasal Vaccination in Guinea Pigs

    PubMed Central

    Veselenak, Ronald L.; Li, Yansong; Yu, Jieh-Juen; Murthy, Ashlesh K.; Cap, Andrew P.; Guentzel, M. Neal; Chambers, James P.; Zhong, Guangming; Rank, Roger G.; Pyles, Richard B.; Arulanandam, Bernard P.

    2014-01-01

    Guinea pigs have been used as a second animal model to validate putative anti-chlamydial vaccine candidates tested in mice. However, the lack of guinea pig-specific reagents has limited the utility of this animal model in Chlamydia sp. vaccine studies. Using a novel guinea pig-specific transcriptome array, we determined correlates of protection in guinea pigs vaccinated with Chlamydia caviae (C. caviae) via the intranasal route, previously reported by us and others to provide robust antigen specific immunity against subsequent intravaginal challenge. C. caviae vaccinated guinea pigs resolved genital infection by day 3 post challenge. In contrast, mock vaccinated animals continued to shed viable Chlamydia up to day 18 post challenge. Importantly, at day 80 post challenge, vaccinated guinea pigs experienced significantly reduced genital pathology - a sequelae of genital chlamydial infections, in comparison to mock vaccinated guinea pigs. Sera from vaccinated guinea pigs displayed antigen specific IgG responses and increased IgG1 and IgG2 titers capable of neutralizing GPIC in vitro. Th1-cellular/inflammatory immune genes and Th2-humoral associated genes were also found to be elevated in vaccinated guinea pigs at day 3 post-challenge and correlated with early clearance of the bacterium. Overall, this study provides the first evidence of guinea pig-specific genes involved in anti-chlamydial vaccination and illustrates the enhancement of the utility of this animal model in chlamydial pathogenesis. PMID:25502875

  17. Use of a Guinea pig-specific transcriptome array for evaluation of protective immunity against genital chlamydial infection following intranasal vaccination in Guinea pigs.

    PubMed

    Wali, Shradha; Gupta, Rishein; Veselenak, Ronald L; Li, Yansong; Yu, Jieh-Juen; Murthy, Ashlesh K; Cap, Andrew P; Guentzel, M Neal; Chambers, James P; Zhong, Guangming; Rank, Roger G; Pyles, Richard B; Arulanandam, Bernard P

    2014-01-01

    Guinea pigs have been used as a second animal model to validate putative anti-chlamydial vaccine candidates tested in mice. However, the lack of guinea pig-specific reagents has limited the utility of this animal model in Chlamydia sp. vaccine studies. Using a novel guinea pig-specific transcriptome array, we determined correlates of protection in guinea pigs vaccinated with Chlamydia caviae (C. caviae) via the intranasal route, previously reported by us and others to provide robust antigen specific immunity against subsequent intravaginal challenge. C. caviae vaccinated guinea pigs resolved genital infection by day 3 post challenge. In contrast, mock vaccinated animals continued to shed viable Chlamydia up to day 18 post challenge. Importantly, at day 80 post challenge, vaccinated guinea pigs experienced significantly reduced genital pathology - a sequelae of genital chlamydial infections, in comparison to mock vaccinated guinea pigs. Sera from vaccinated guinea pigs displayed antigen specific IgG responses and increased IgG1 and IgG2 titers capable of neutralizing GPIC in vitro. Th1-cellular/inflammatory immune genes and Th2-humoral associated genes were also found to be elevated in vaccinated guinea pigs at day 3 post-challenge and correlated with early clearance of the bacterium. Overall, this study provides the first evidence of guinea pig-specific genes involved in anti-chlamydial vaccination and illustrates the enhancement of the utility of this animal model in chlamydial pathogenesis.

  18. Blood-Feeding Behaviors of Anopheles stephensi but not Phlebotomus papatasi are Influenced by Actively Warming Guinea Pigs (Cavia porcellus) Under General Anesthesia.

    PubMed

    Buchta, Jessica N; Zarndt, Bethany S; Garver, Lindsey S; Rowland, Tobin; Shi, Meng; Davidson, Silas A; Rowton, Edgar D

    2015-06-01

    Animal models are often used to study hematophagous insect feeding behavior and evaluate products such as topical repellents. However, when these models are used the study animals often experience significant drops in core body temperature because of the effects of anesthesia. This study used a guinea pig model to investigate whether maintaining a normothermic core body temperature during anesthesia influenced the rate of Anopheles stephensi and Phlebotomus papatasi blood feeding. Experiments were conducted with anesthetized animals that had their body temperatures either maintained with a warming device or were allowed to drop naturally. Results showed that when guinea pigs were actively warmed by a heating device, An. stephensi feeding behavior was similar at the beginning and end of anesthesia. However, when a warming device was not used, fewer An. stephensi took a blood meal after the animals' temperatures had dropped. Phlebotomus papatasi were not as sensitive to changes in temperature and feeding rates were similar whether a warming device was used or not. These results are discussed and it is recommended that warming devices are used when conducting feeding experiments with insects sensitive to changes in host body temperature, such as An. stephensi.

  19. Spatio-temporal expression of MMP-2, MMP-9 and tissue kallikrein in uteroplacental units of the pregnant guinea-pig (Cavia porcellus)

    PubMed Central

    Corthorn, Jenny; Rey, Sergio; Chacón, Cecilia; Valdés, Gloria

    2007-01-01

    Background In humans trophoblast invasion and vascular remodeling are critical to determine the fate of pregnancy. Since guinea-pigs share with women an extensive migration of the trophoblasts through the decidua and uterine arteries, and a haemomonochorial placenta, this species was used to evaluate the spatio-temporal expression of three enzymes that have been associated to trophoblast invasion, MMP-2, MMP-9 and tissue kallikrein (K1). Methods Uteroplacental units were collected from early to term pregnancy. MMP-2, MMP-9 and K1 were analysed by immunohistochemistry and Western blot. The activities of MMP-2 and MMP-9 were assessed by gelatin zymography. Results Immunoreactive MMP-2, MMP-9 and K1 were detected in the subplacenta, interlobar and labyrinthine placenta, syncytial sprouts and syncytial streamers throughout pregnancy. In late pregnancy, perivascular or intramural trophoblasts expressed the three enzymes. The intensity of the signal in syncytial streamers was increased in mid and late pregnancy for MMP-2, decreased in late pregnancy for MMP-9, and remained stable for K1. Western blots of placental homogenates at days 20, 40 and 60 of pregnancy identified bands with the molecular weights of MMP-2, MMP-9 and K1. MMP-2 expression remained constant throughout gestation. In contrast, MMP-9 and K1 attained their highest expression during midgestation. Placental homogenates of 20, 40 and 60 days yielded bands of gelatinase activity that were compatible with MMP-2 and MMP-9 activities. ProMMP-2 and MMP-9 activities did not vary along pregnancy, while MMP-2 and MMP-9 increased at 40 and 40–60 days respectively. Conclusion The spatio-temporal expression of MMPs and K1 supports a relevant role of these proteins in trophoblast invasion, vascular remodeling and placental angiogenesis, and suggests a functional association between K1 and MMP-9 activation. PMID:17605824

  20. Spot-on Treatments of Diflubenzuron and Permethrin to Control a Guinea Pig Louse, Gliricola Porcelli (Phthiraptera: Gyropidae)

    USDA-ARS?s Scientific Manuscript database

    Guinea pigs (Cavia porcellus (L.)) (Rodentia: Caviidae) are pets and laboratory animals. They can be infested by a chewing louse, Gliricola porcelli (Schrank) (Phthiraptera: Gyropidae), which is fairly common in some animal rearing facilities, pet stores, and on wild guinea pigs. Infestation with G....

  1. [Guinea pigs and dermatophytosis].

    PubMed

    Khettar, L; Contet-Audonneau, N

    2012-10-01

    The current trend of keeping "exotic" pets has led to the emergence of new types of fungal species that may be transmitted to humans [1]. We describe a form of dermatophytosis transmitted by a Guinea pig and caused by a new variety of dermatophyte. A 13-year-old girl developed multiple erythematosquamous and vesicular lesions with a highly inflammatory edge several weeks after acquiring a Guinea pig of apparently healthy appearance. Direct examination and culture tests demonstrated the presence of a dermatophyte closely related to the erinacei variant of Trichophyton mentagrophytes, from which it differed in terms of microscopic and macroscopic characteristics. The condition resolved on therapy with topical imidazole. This new type of dermatophyte has been identified in many patients coming into close contact with Guinea pigs in the region of Nancy. We would suggest the emergence of a novel variety of T. mentagrophytes, which has adapted to its new host following transmission to Guineas pigs from hedgehogs. We propose that it be named T. mentagrophytes var. porcellae. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  2. Immunological relationships of an endogenous guinea pig retrovirus with prototype mammalian type B and type D retroviruses.

    PubMed Central

    Dahlberg, J E; Tronick, S R; Aaronson, S A

    1980-01-01

    A retrovirus endogenous to guinea pig cells was earlier shown to be morphologically similar to type B and type D prototype retroviruses. Molecular hybridization techniques were used to show that guinea pig virus nucleotide sequences are endogenous to both domestic (Cavia porcellus) and indigenous (Cavia aperea) guinea pigs, but cannot be detected in the DNA of either other hystricomorph rodents or other mammals tested. Using radioimmunological techniques designed to detect interspecies relationships, the major internal polypeptide of guinea pig virus (p26) was shown to share three different sets of interspecies antigenic determinants with squirrel monkey retrovirus, viper retrovirus, and mouse mammary tumor virus. Thus, guinea pig virus appears to provide an evolutionary link between type B and D retroviruses. Images PMID:6154150

  3. An ecologically relevant guinea pig model of fetal behavior

    PubMed Central

    Bellinger, S. A.; Lucas, D.; Kleven, G. A.

    2015-01-01

    The laboratory guinea pig, Cavia porcellus, shares with humans many similarities during pregnancy and prenatal development, including precocial offspring and social dependence. These similarities suggest the guinea pig as a promising model of fetal behavioral development as well. Using innovative methods of behavioral acclimation, fetal offspring of female IAF hairless guinea pigs time mated to NIH multi-colored Hartley males were observed longitudinally without restraint using noninvasive ultrasound at weekly intervals across the 10 week gestation. To insure that the ultrasound procedure did not cause significant stress, salivary cortisol was collected both before and after each observation. Measures of fetal spontaneous movement and behavioral state were quantified from video recordings from week 3 through the last week before birth. Results from prenatal quantification of Interlimb Movement Synchrony and state organization reveal guinea pig fetal development to be strikingly similar to that previously reported for other rodents and preterm human infants. Salivary cortisol readings taken before and after sonography did not differ at any observation time point. These results suggest this model holds translational promise for studying the prenatal mechanisms of neurobehavioral development, including those that may result from adverse events. Because the guinea pig is a highly social mammal with a wide range of socially oriented vocalizations, this model may also have utility for studying the prenatal origins and trajectories of developmental disabilities with social-emotional components, such as autism. PMID:25655512

  4. Identification of guinea pig gammadelta T cells and characterization during pulmonary tuberculosis.

    PubMed

    Xiong, Xiaowei; Morita, Craig T; Bukowski, Jack F; Brenner, Michael B; Dascher, Christopher C

    2004-11-01

    Guinea pigs are an alternative small animal model for many disease studies. Here we describe a pan-gammadelta monoclonal antibody (anti-TCRdelta1) specific for the constant region of human T cell receptor delta chains that cross-reacts with a subpopulation of guinea pig (Cavia porcellus) lymphocytes. The phenotype and distribution of this subpopulation is consistent with the guinea pig gammadelta T cell subset. FACS analysis of fresh PBMC and splenocytes from naïve guinea pigs revealed the presence of a subset of cells that stained with the anti-TCRdelta1 mAb. The relative percentage of anti-TCRdelta1 positive cells in PBMC and tissues is similar to that described for gammadelta T cells in other species. Immunohistochemistry of tissues also revealed a distribution of anti-TCRdelta1 positive cells consistent with gammadelta T cells. These data are further supported by staining of a polyclonal guinea pig T cell line that became progressively CD4 and CD8 negative in long-term culture. Analysis of PBMC from guinea pigs following aerosol infection with virulent Mycobacterium tuberculosis revealed no apparent changes in the steady-state percentage of blood gammadelta+ T cells. Taken together, these data suggest that the anti-TCRdelta1 antibody recognizes the gammadelta T cell subset in guinea pigs. This reagent may be useful for examining gammadelta T cells in various disease models where the guinea pig is a more desirable model for study.

  5. Guinea Pig ID-Like Families of SINEs

    PubMed Central

    Kass, David H.; Schaetz, Brian A.; Beitler, Lindsey; Bonney, Kevin M.; Jamison, Nicole; Wiesner, Cathy

    2009-01-01

    Previous studies have indicated a paucity of SINEs within the genomes of the guinea pig and nutria, representatives of the Hystricognathi suborder of rodents. More recent work has shown that the guinea pig genome contains a large number of B1 elements, expanding to various levels among different rodents. In this work we utilized A–B PCR and screened GenBank with sequences from isolated clones to identify potentially uncharacterized SINEs within the guinea pig genome, and identified numerous sequences with a high degree of similarity (>92%) specific to the guinea pig. The presence of A-tails and flanking direct repeats associated with these sequences supported the identification of a full-length SINE, with a consensus sequence notably distinct from other rodent SINEs. Although most similar to the ID SINE, it clearly was not derived from the known ID master gene (BC1), hence we refer to this element as guinea pig ID-like (GPIDL). Using the consensus to screen the guinea pig genomic database (Assembly CavPor2) with Ensembl BlastView, we estimated at least 100,000 copies, which contrasts markedly to just over 100 copies of ID elements. Additionally we provided evidence of recent integrations of GPIDL as two of seven analyzed conserved GPIDL-containing loci demonstrated presence/absence variants in Cavia porcellus and C. aperea. Using intra-IDL PCR and sequence analyses we also provide evidence that GPIDL is derived from a hystricognath-specific SINE family. These results demonstrate that this SINE family continues to contribute to the dynamics of genomes of hystricognath rodents. PMID:19232383

  6. Guinea pig ID-like families of SINEs.

    PubMed

    Kass, David H; Schaetz, Brian A; Beitler, Lindsey; Bonney, Kevin M; Jamison, Nicole; Wiesner, Cathy

    2009-05-01

    Previous studies have indicated a paucity of SINEs within the genomes of the guinea pig and nutria, representatives of the Hystricognathi suborder of rodents. More recent work has shown that the guinea pig genome contains a large number of B1 elements, expanding to various levels among different rodents. In this work we utilized A-B PCR and screened GenBank with sequences from isolated clones to identify potentially uncharacterized SINEs within the guinea pig genome, and identified numerous sequences with a high degree of similarity (>92%) specific to the guinea pig. The presence of A-tails and flanking direct repeats associated with these sequences supported the identification of a full-length SINE, with a consensus sequence notably distinct from other rodent SINEs. Although most similar to the ID SINE, it clearly was not derived from the known ID master gene (BC1), hence we refer to this element as guinea pig ID-like (GPIDL). Using the consensus to screen the guinea pig genomic database (Assembly CavPor2) with Ensembl BlastView, we estimated at least 100,000 copies, which contrasts markedly to just over 100 copies of ID elements. Additionally we provided evidence of recent integrations of GPIDL as two of seven analyzed conserved GPIDL-containing loci demonstrated presence/absence variants in Cavia porcellus and C. aperea. Using intra-IDL PCR and sequence analyses we also provide evidence that GPIDL is derived from a hystricognath-specific SINE family. These results demonstrate that this SINE family continues to contribute to the dynamics of genomes of hystricognath rodents.

  7. Guinea-pig reaginic antibody

    PubMed Central

    Margni, R. A.; Hajos, Silvia E.

    1973-01-01

    The physicochemical and biological properties of purified guinea-pig reaginic antibody were studied. It is a labile protein different to γ1. Its antibody activity is completely destroyed by heating at 56° for 6 hours and by treatment with mercaptoethanol. The capacity to give PCA is decreased by repeated freezing and thawing. It is a bivalent antibody, haemagglutinating, does not fix complement and is capable of sensitizing guinea-pig skin for PCA reaction after a latent period of a week but not after 3 hours. Reaginic antibody appears on day 7–8 after the first inoculation and the higher levels (PCA reaction) are obtained at the eleventh to thirteenth days. After the fifteenth to seventeenth days the PCA is negative. The reaginic antibody does not pass the placenta. Higher levels of reaginic antibody were obtained when the guinea-pigs were inoculated with the antigen in saline with simultaneous inoculation, intraperitoneally, of killed Bordetella pertussis, phase I. PMID:4354828

  8. Guinea-pig reaginic antibody

    PubMed Central

    Margni, R. A.; Hajos, Silvia E.

    1973-01-01

    The methods for isolation and purification of a guinea-pig serum protein with homocytotropic antibody activity and characteristics of IgE are described. By precipitation in the equivalence zone or immunoadsorption and chromatography on DEAE-cellulose, we isolated an homocytotropic antibody, that was not able to give a precipitin line when it was reacted directly with the antigen. It was capable of sensitizing guinea-pig skin for PCA after a latent period of 24–48 hours but not after 3 hours; it was sensitive to treatment with mercaptoethanol. It had antigenic determinants present in the other guinea-pig immunoglobulins and particular antigenic determinants. All these properties make us believe that this protein belongs to an immunoglobulin different from γ1 and similar to the reaginic antibody (IgE) described in other species. ImagesFIG. 3FIG. 4FIG. 5 PMID:4126261

  9. Comparative proteomic analysis of lung tissue from guinea pigs with Leptospiral Pulmonary Haemorrhage Syndrome (LPHS) reveals a decrease in abundance of host proteins involved in cytoskeletal and cellular organization

    USDA-ARS?s Scientific Manuscript database

    The recent completion of the complete genome sequence of the guinea pig (Cavia porcellus) provides innovative opportunities to apply proteomic technologies to an important animal model of disease. In this study, a 2-D guinea pig proteome lung map was used to investigate the pathogenic mechanisms of ...

  10. Micro-endoscopic ear anatomy of guinea pig applied to experimental surgery.

    PubMed

    Barros, Bruno Borges de Carvalho; Andrade, José Santos Cruz de; Garcia, Leandro Borborema; Pifaia, Gustavo Ribeiro; Cruz, Oswaldo Laércio Mendonça; Onishi, Ektor Tsuneo; Penido, Norma de Oliveira

    2014-01-01

    To describe topographic and endoscopic anatomy of guinea pig ear for development of surgical approaches in experimental studies. Experimental study. Eight adult guinea pigs (Cavia porcellus) were used in this study. Four animals were described through endoscopic view and four animals were used to describe topographic anatomy. The main structures of middle ear were well identified through endoscopy view: oval and round window, ossicles and vascular structures. Temporal bone position, landmarks and its relations to skull are perceived with topographic description. Topographic anatomic description allowed exposition of temporal bone relations for external surgical approaches. Alternatively, grooves and middle ear structures were identified and may be used to transcanal accesses.

  11. Prokaryotic Expression and In vitro Functional Analysis of IL-1 and MCP-1 from Guinea Pig

    PubMed Central

    Dirisala, Vijaya R.; Jeevan, Amminikutty; Ly, Lan H.; McMurray, David N.

    2012-01-01

    The Guinea pig (Cavia porcellus) is an excellent animal model for studying human tuberculosis (TB) and also for a number of other infectious and non-infectious diseases. One of the major roadblocks in effective utilization of this animal model is the lack of readily available immunological reagents. In order to address this issue, guinea pig interleukin 1 beta (IL-1β) and monocyte chemo attractant protein-1 (MCP-1) were efficiently cloned and expressed in a prokaryotic expression vector (pET-30a) and the expressed proteins in soluble form from both the genes were confirmed by N-terminal sequencing. The biological activity of recombinant guinea pig IL-1β was demonstrated by its ability to drive proliferation in thymocytes and the recombinant guinea pig MCP-1 exhibited chemotactic activity for guinea pig resident peritoneal macrophages. These biologically active recombinant guinea pig proteins will facilitate an in-depth understanding of the role they play in the immune responses of the guinea pig to TB and other diseases. PMID:22744745

  12. Diseases in pet guinea pigs: a retrospective study in 1000 animals.

    PubMed

    Minarikova, A; Hauptman, K; Jeklova, E; Knotek, Z; Jekl, V

    2015-08-22

    Guinea pigs are commonly kept as pet animals; however, information about particular disease prevalence is lacking. The objective of this article was to present disease prevalence in 1000 pet guinea pigs from private owners divided into three age groups: under two years; between two and five years; and above five years. Medical records of guinea pigs (Cavia aperea f. porcellus) that were presented to the authors' clinic in the period from January 2008 to August 2013 were reviewed. The most commonly diagnosed disease in guinea pigs was dental disease (36.3 per cent), with higher prevalence in the middle age group (P<0.001) and in males (P<0.001) rather than females. Skin problems were seen as the second most common disease (33.3 per cent), with higher prevalence in male guinea pigs (P<0.001) and in animals younger than two years (P<0.001). Ovarian cystic disease was the third most commonly seen disorder, with higher prevalence in females older than two years (P<0.001). Other common health disorders included gastrointestinal stasis, heterotopic ciliary body calcifications, fatty eye and tibiofemoral osteoarthritis. Only 81 guinea pigs from a total of 1000 animals were healthy. This is the first study to describe the disease prevalence in three age groups of pet guinea pigs. British Veterinary Association.

  13. A guinea pig model of bovine pneumonic pasteurellosis.

    PubMed Central

    Morck, D W; Costerton, J W; Bolingbroke, D O; Ceri, H; Boyd, N D; Olson, M E

    1990-01-01

    The induction of pneumonic pasteurellosis in guinea pigs (Cavia porcellus) was examined. Specific pathogen free male guinea pigs were anesthetized and a tracheostomy performed to introduce 10(5), 10(4) or 10(3) Pasteurella haemolytica-A1 into the left principal bronchus. The surgical site was closed with tissue adhesive and staples and the animals were monitored for signs of respiratory tract infection. Within 24 hours after inoculation they became depressed, anorectic, pyretic and dyspneic. Fibrinous pleuropneumonia with prominent areas of necrosis and hemorrhage was present. Pericardial effusion was a frequent finding. There was infiltration of the pleura and alveoli with degenerate heterophils and macrophages, a hyperplastic mesothelium and fibrin exudation on the pleura and within alveoli. Hemorrhage, congestion, consolidation, edema and fibrin exudation were prominent in the hilar region of the lungs. Bacterial colonies were evident in all airways. More bacteria were recovered from infected lungs than were inoculated (p less than 0.05) indicating P. haemolytica was actively multiplying in the lungs. Hematological and clinical chemistry data were consistent with fibrinous pneumonia, however, blood cultures were positive for P. haemolytica in 61% (11/18) of animals sampled. Examination of pneumonic pasteurellosis in guinea pigs may be useful in studying pathogenetic and pathological features applicable to bovine pneumonic pasteurellosis (shipping fever pneumonia). Images Fig. 1. Fig. 2. Fig. 4. Fig. 5. Fig. 7. Fig. 8. Fig. 9. PMID:2306663

  14. Pathogenesis of Bolivian Hemorrhagic Fever in Guinea Pigs.

    PubMed

    Bell, T M; Bunton, T E; Shaia, C I; Raymond, J W; Honnold, S P; Donnelly, G C; Shamblin, J D; Wilkinson, E R; Cashman, K A

    2016-01-01

    Machupo virus, the cause of Bolivian hemorrhagic fever, is a highly lethal viral hemorrhagic fever with no Food and Drug Administration-approved vaccines or therapeutics. This study evaluated the guinea pig as a model using the Machupo virus-Chicava strain administered via aerosol challenge. Guinea pigs (Cavia porcellus) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and sequential changes in serum chemistry and hematology. The incubation period was 5 to 12 days, and complete blood counts revealed leukopenia with lymphopenia and thrombocytopenia. Gross pathologic findings included congestion and hemorrhage of the gastrointestinal mucosa and serosa, noncollapsing lungs with fluid exudation, enlarged lymph nodes, and progressive pallor and friability of the liver. Histologic lesions consisted of foci of degeneration and cell death in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, renal pelvis, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system, interpreted as nonsuppurative encephalitis, was histologically apparent approximately 16 days postexposure and was generally progressive. Macrophages in the tracheobronchial lymph node, on day 5 postexposure, were the first cells to demonstrate visible viral antigen. Viral antigen was detected throughout the lymphoid system by day 9 postexposure, followed by prominent spread within epithelial tissues and then brain. This study provides insight into the course of Machupo virus infection and supports the utility of guinea pigs as an additional animal model for vaccine and therapeutic development.

  15. The potential application of hairless guinea pigs as a replacement for the Yucatan mini-pig in animal studies

    NASA Astrophysics Data System (ADS)

    Jindra, Nichole M.; Imholte, Michelle L.

    2008-02-01

    The Yucatan mini-pig (Sus scrofa) is one of the most widely used animal models for skin damage studies because it shares many of the same physical properties as human skin. While the Yucatan is ideal for laser exposure studies using a large spot size, its size and cost are excessive for projects using smaller beams. This experiment performed histological analysis of skin biopsies from pigmented Hairless Guinea Pigs (Cavia porcellus) for epidermal thickness and melanin concentration. That data was then compared to similar information on the Yucatan.

  16. Naturally occurring Parelaphostrongylus tenuis-associated choriomeningitis in a guinea pig with neurologic signs.

    PubMed

    Southard, T; Bender, H; Wade, S E; Grunenwald, C; Gerhold, R W

    2013-05-01

    An adult male guinea pig (Cavia porcellus) with a 1-month history of hind limb paresis, torticollis, and seizures was euthanized and submitted for necropsy. Gross examination was unremarkable, but histologic examination revealed multifocal eosinophilic and lymphoplasmacytic choriomeningitis and cross sections of nematode parasites within the leptomeninges of the midbrain and diencephalon. Morphologic features of the nematode were consistent with a metastrongyle, and the parasite was identified as Parelaphostrongylus tenuis by polymerase chain reaction testing and nucleotide sequencing. Further questioning of the owner revealed that the guinea pig was fed grass from a yard often grazed by white-tailed deer (Odocoileus virginianus). To the authors' knowledge, this is the first report of a naturally occurring P. tenuis infection in a guinea pig.

  17. Molecular cloning and expression of the IL-10 gene from guinea pigs.

    PubMed

    Dirisala, Vijaya R; Jeevan, Amminikutty; Bix, Gregory; Yoshimura, Teizo; McMurray, David N

    2012-04-25

    The Guinea pig (Cavia porcellus) is one of the most relevant small animals for modeling human tuberculosis (TB) in terms of susceptibility to low dose aerosol infection, the organization of granulomas, extrapulmonary dissemination and vaccine-induced protection. It is also considered to be a gold standard for a number of other infectious and non-infectious diseases; however, this animal model has a major disadvantage due to the lack of readily available immunological reagents. In the present study, we successfully cloned a cDNA for the critical Th2 cytokine, interleukin-10 (IL-10), from inbred Strain 2 guinea pigs using the DNA sequence information provided by the genome project. The complete open reading frame (ORF) consists of 537 base pairs which encodes a protein of 179 amino acids. This cDNA sequence exhibited 87% homology with human IL-10. Surprisingly, it showed only 84% homology with the previously published IL-10 sequence from the C4-deficient (C4D) guinea pig, leading us to clone IL-10 cDNA from the Hartley strain of guinea pig. The IL-10 gene from the Hartley strain showed 100% homology with the IL-10 sequence of Strain 2 guinea pigs. In order to validate the only published IL-10 sequence existing in Genbank reported from C4D guinea pigs, genomic DNA was isolated from tissues of C4D guinea pigs. Amplification with various sets of primers showed that the IL-10 sequence reported from C4D guinea pigs contained numerous errors. Hence the IL-10 sequence that is being reported by us replaces the earlier sequence making our IL-10 sequence to be the first one accurate from guinea pig. Recombinant guinea pig IL-10 proteins were subsequently expressed in both prokaryotic and eukaryotic cells, purified and were confirmed by N-terminal sequencing. Polyclonal anti-IL-10 antibodies were generated in rabbits using the recombinant IL-10 protein expressed in this study. Taken together, our results indicate that the DNA sequence information provided by the genome project

  18. Guinea Pigs: Versatile Animals for the Classroom

    ERIC Educational Resources Information Center

    Barman, Charles R.

    1977-01-01

    Guinea pigs are presented as versatile classroom animals. Suggestions for animal behavior and genetics studies are given. Also included is information concerning sex determination and the breeding of guinea pigs, and hints on keeping these animals in the classroom. References and illustrations complete the article. (MA)

  19. Guinea Pigs: Versatile Animals for the Classroom

    ERIC Educational Resources Information Center

    Barman, Charles R.

    1977-01-01

    Guinea pigs are presented as versatile classroom animals. Suggestions for animal behavior and genetics studies are given. Also included is information concerning sex determination and the breeding of guinea pigs, and hints on keeping these animals in the classroom. References and illustrations complete the article. (MA)

  20. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Guinea pig safety test. 113.38 Section... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section... be injected either intramuscularly or subcutaneously into each of two guinea pigs and the animals...

  1. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Guinea pig safety test. 113.38 Section... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section... be injected either intramuscularly or subcutaneously into each of two guinea pigs and the animals...

  2. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Guinea pig safety test. 113.38 Section... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section... be injected either intramuscularly or subcutaneously into each of two guinea pigs and the animals...

  3. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Guinea pig safety test. 113.38 Section... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section... be injected either intramuscularly or subcutaneously into each of two guinea pigs and the animals...

  4. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Guinea pig safety test. 113.38 Section... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section... be injected either intramuscularly or subcutaneously into each of two guinea pigs and the...

  5. Guinea Pig Ciliary Muscle Development

    PubMed Central

    Pucker, Andrew D.; Carpenter, Ashley R.; McHugh, Kirk M.; Mutti, Donald O.

    2014-01-01

    Purpose The purpose of this study was to develop a method for quantifying guinea pig ciliary muscle volume (CMV) and to determine its relationship to age and ocular biometric measurements. Methods Six albino guinea pigs eyes were collected at each of five ages (n=30 eyes). Retinoscopy and photography were used to document refractive error, eye size, and eye shape. Serial sections through the excised eyes were made and then labeled with an α-smooth muscle actin antibody. The CM was then visualized with an Olympus BX51 microscope, reconstructed with Stereo Investigator (MBF Bioscience) and analyzed using Neurolucida Explorer (MBF Bioscience). Full (using all sections) and partial (using a subset of sections) reconstruction methods were used to determine CMV. Results There was no significant difference between the full and partial volume determination methods (P = 0.86). The mean CMV of the 1, 10, 20, 30, and 90-day old eyes was 0.40 ± 0.16 mm3, 0.48 ± 0.13 mm3, 0.67 ± 0.15 mm3, 0.86 ± 0.35 mm3, and 1.09 ± 0.63 mm3, respectively. CMV was significantly correlated with log age (P = 0.001), ocular length (P = 0.003), limbal circumference (P = 0.01), and equatorial diameter (P = 0.003). It was not correlated with refractive error (P = 0.73) or eye shape (P = 0.60). Multivariate regression determined that biometric variables were not significantly associated with CMV after adjustment for age. Conclusions Three-dimensional reconstruction was an effective means of determining CMV. These data provide evidence that CM growth occurs with age in tandem with eye size in normal albino guinea pigs. Additional work is needed to determine the relationship between CMV and abnormal ocular growth. PMID:24901488

  6. Experimental aerosolized guinea pig-adapted Zaire ebolavirus (variant: Mayinga) causes lethal pneumonia in guinea pigs.

    PubMed

    Twenhafel, N A; Shaia, C I; Bunton, T E; Shamblin, J D; Wollen, S E; Pitt, L M; Sizemore, D R; Ogg, M M; Johnston, S C

    2015-01-01

    Eight guinea pigs were aerosolized with guinea pig-adapted Zaire ebolavirus (variant: Mayinga) and developed lethal interstitial pneumonia that was distinct from lesions described in guinea pigs challenged subcutaneously, nonhuman primates challenged by the aerosol route, and natural infection in humans. Guinea pigs succumbed with significant pathologic changes primarily restricted to the lungs. Intracytoplasmic inclusion bodies were observed in many alveolar macrophages. Perivasculitis was noted within the lungs. These changes are unlike those of documented subcutaneously challenged guinea pigs and aerosolized filoviral infections in nonhuman primates and human cases. Similar to findings in subcutaneously challenged guinea pigs, there were only mild lesions in the liver and spleen. To our knowledge, this is the first report of aerosol challenge of guinea pigs with guinea pig-adapted Zaire ebolavirus (variant: Mayinga). Before choosing this model for use in aerosolized ebolavirus studies, scientists and pathologists should be aware that aerosolized guinea pig-adapted Zaire ebolavirus (variant: Mayinga) causes lethal pneumonia in guinea pigs. © The Author(s) 2014.

  7. Wild genius - domestic fool? Spatial learning abilities of wild and domestic guinea pigs.

    PubMed

    Lewejohann, Lars; Pickel, Thorsten; Sachser, Norbert; Kaiser, Sylvia

    2010-03-25

    Domestic animals and their wild relatives differ in a wide variety of aspects. The process of domestication of the domestic guinea pig (Cavia aperea f. porcellus), starting at least 4500 years ago, led to changes in the anatomy, physiology, and behaviour compared with their wild relative, the wild cavy, Cavia aperea. Although domestic guinea pigs are widely used as a laboratory animal, learning and memory capabilities are often disregarded as being very scarce. Even less is known about learning and memory of wild cavies. In this regard, one striking domestic trait is a reduction in relative brain size, which in the domesticated form of the guinea pig amounts to 13%. However, the common belief, that such a reduction of brain size in the course of domestication of different species is accomplished by less learning capabilities is not at all very well established in the literature. Indeed, domestic animals might also even outperform their wild conspecifics taking advantage of their adaptation to a man-made environment.In our study we compared the spatial learning abilities of wild and domestic guinea pigs. We expected that the two forms are different regarding their learning performance possibly related to the process of domestication. Therefore wild cavies as well as domestic guinea pigs of both sexes, aged 35 to 45 days, were tested in the Morris water maze to investigate their ability of spatial learning. Both, wild cavies and domestic guinea pigs were able to learn the task, proving the water maze to be a suitable test also for wild cavies. Regarding the speed of learning, male as well as female domestic guinea pigs outperformed their wild conspecifics significantly. Interestingly, only domestic guinea pigs showed a significant spatial association of the platform position, while other effective search strategies were used by wild cavies. The results demonstrate that domestic guinea pigs do not at all perform worse than their wild relatives in tests of spatial

  8. Wild genius - domestic fool? Spatial learning abilities of wild and domestic guinea pigs

    PubMed Central

    2010-01-01

    Background Domestic animals and their wild relatives differ in a wide variety of aspects. The process of domestication of the domestic guinea pig (Cavia aperea f. porcellus), starting at least 4500 years ago, led to changes in the anatomy, physiology, and behaviour compared with their wild relative, the wild cavy, Cavia aperea. Although domestic guinea pigs are widely used as a laboratory animal, learning and memory capabilities are often disregarded as being very scarce. Even less is known about learning and memory of wild cavies. In this regard, one striking domestic trait is a reduction in relative brain size, which in the domesticated form of the guinea pig amounts to 13%. However, the common belief, that such a reduction of brain size in the course of domestication of different species is accomplished by less learning capabilities is not at all very well established in the literature. Indeed, domestic animals might also even outperform their wild conspecifics taking advantage of their adaptation to a man-made environment. In our study we compared the spatial learning abilities of wild and domestic guinea pigs. We expected that the two forms are different regarding their learning performance possibly related to the process of domestication. Therefore wild cavies as well as domestic guinea pigs of both sexes, aged 35 to 45 days, were tested in the Morris water maze to investigate their ability of spatial learning. Results Both, wild cavies and domestic guinea pigs were able to learn the task, proving the water maze to be a suitable test also for wild cavies. Regarding the speed of learning, male as well as female domestic guinea pigs outperformed their wild conspecifics significantly. Interestingly, only domestic guinea pigs showed a significant spatial association of the platform position, while other effective search strategies were used by wild cavies. Conclusion The results demonstrate that domestic guinea pigs do not at all perform worse than their wild

  9. Development of a novel, guinea pig-specific IFN-γ ELISPOT assay and characterization of guinea pig cytomegalovirus GP83-specific cellular immune responses following immunization with a modified vaccinia virus Ankara (MVA)-vectored GP83 vaccine.

    PubMed

    Gillis, Peter A; Hernandez-Alvarado, Nelmary; Gnanandarajah, Josephine S; Wussow, Felix; Diamond, Don J; Schleiss, Mark R

    2014-06-30

    The guinea pig (Cavia porcellus) provides a useful animal model for studying the pathogenesis of many infectious diseases, and for preclinical evaluation of vaccines. However, guinea pig models are limited by the lack of immunological reagents required for characterization and quantification of antigen-specific T cell responses. To address this deficiency, an enzyme-linked immunospot (ELISPOT) assay for guinea pig interferon (IFN)-γ was developed to measure antigen/epitope-specific T cell responses to guinea pig cytomegalovirus (GPCMV) vaccines. Using splenocytes harvested from animals vaccinated with a modified vaccinia virus Ankara (MVA) vector encoding the GPCMV GP83 (homolog of human CMV pp65 [gpUL83]) protein, we were able to enumerate and map antigen-specific responses, both in vaccinated as well as GPCMV-infected animals, using a panel of GP83-specific peptides. Several potential immunodominant GP83-specific peptides were identified, including one epitope, LGIVHFFDN, that was noted in all guinea pigs that had a detectable CD8+ response to GP83. Development of a guinea pig IFN-γ ELISPOT should be useful in characterization of additional T cell-specific responses to GPCMV, as well as other pathogens. This information in turn can help focus future experimental evaluation of immunization strategies, both for GPCMV as well as for other vaccine-preventable illnesses studied in the guinea pig model.

  10. Development of a novel, guinea pig-specific IFN-γ ELISPOT assay and characterization of guinea pig cytomegalovirus GP83-specific cellular immune responses following immunization with a modified vaccinia virus Ankara (MVA)-vectored GP83 vaccine

    PubMed Central

    Gillis, Peter A.; Hernandez-Alvarado, Nelmary; Gnanandarajah, Josephine S.; Wussow, Felix; Diamond, Don J.; Schleiss, Mark R.

    2014-01-01

    The guinea pig (Cavia porcellus) provides a useful animal model for studying the pathogenesis of many infectious diseases, and for preclinical evaluation of vaccines. However, guinea pig models are limited by the lack of immunological reagents required for characterization and quantification of antigen-specific T cell responses. To address this deficiency, an enzyme-linked immunospot (ELISPOT) assay for guinea pig interferon (IFN)-γ was developed to measure antigen/epitope-specific T cell responses to guinea pig cytomegalovirus (GPCMV) vaccines. Using splenocytes harvested from animals vaccinated with a modified vaccinia virus Ankara (MVA) vector encoding the GPCMV GP83 (homolog of human CMV pp65 [gpUL83]) protein, we were able to enumerate and map antigen-specific responses, both in vaccinated as well as GPCMV-infected animals, using a panel of GP83-specific peptides. Several potential immunodominant GP83-specific peptides were identified, including one epitope, LGIVHFFDN, that was noted in all guinea pigs that had a detectable CD8+ response to GP83. Development of a guinea pig IFN-γ ELISPOT should be useful in characterization of additional T cell-specific responses to GPCMV, as well as other pathogens. This information in turn can help focus future experimental evaluation of immunization strategies, both for GPCMV as well as for other vaccine-preventable illnesses studied in the guinea pig model. PMID:24856783

  11. Prokaryotic expression and in vitro functional analysis of IL-1β and MCP-1 from guinea pig.

    PubMed

    Dirisala, Vijaya R; Jeevan, Amminikutty; Ly, Lan H; McMurray, David N

    2013-06-01

    The Guinea pig (Cavia porcellus) is an excellent animal model for studying human tuberculosis (TB) and also for a number of other infectious and non-infectious diseases. One of the major roadblocks in effective utilization of this animal model is the lack of readily available immunological reagents. In order to address this issue, guinea pig interleukin 1 beta (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) were efficiently cloned and expressed in a prokaryotic expression vector, and the expressed proteins in soluble form from both the genes were confirmed by N-terminal sequencing. The biological activity of recombinant guinea pig IL-1β was demonstrated by its ability to drive proliferation in thymocytes, and the recombinant guinea pig MCP-1 exhibited chemotactic activity for guinea pig resident peritoneal macrophages. These biologically active recombinant guinea pig proteins will facilitate an in-depth understanding of the role they play in the immune responses of the guinea pig to TB and other diseases.

  12. Animal Models of Tuberculosis: Guinea Pigs

    PubMed Central

    Clark, Simon; Hall, Yper; Williams, Ann

    2015-01-01

    The progression of the disease that follows infection of guinea pigs with Mycobacterium tuberculosis displays many features of human tuberculosis (TB), and the guinea pig model of TB has been used for more than 100 years as a research tool to understand and describe disease mechanisms. Changes in the bacterial burden and pathology following infection can be readily monitored and used to evaluate the impact of TB interventions. Demonstration of the protective efficacy of vaccines in the low-dose aerosol guinea pig model is an important component of the preclinical data package for novel vaccines in development, and there is a continual need to improve the model to facilitate progression of vaccines to the clinic. Development of better tools with which to dissect the immune responses of guinea pigs is a focus of current research. PMID:25524720

  13. [Dermophytes and guinea pigs : An underestimated danger?

    PubMed

    Kupsch, C; Berlin, M; Gräser, Y

    2017-06-14

    For several years, an increasing number of human infections, mainly affecting children, with the zoophilic dermatophyte Trichophyton benhamiae has been observed. It is predominantly transmitted by pet guinea pigs. The prevalence of the dermatophyte on guinea pigs which are for sale in pet shops is unknown. Therefore, the aim of this study was to analyze the frequency of T. benhamiae on symptomatic and asymptomatic guinea pigs from pet shops in Berlin. We sampled 59 guinea pigs from 15 pet shops using toothbrushes (MacKenzie brush technique) and FLOQswabs™ and analyzed the material for the presence of T. benhamiae with polymerase chain reaction (PCR) and culture. We detected T. benhamiae on more than 90% of the guinea pigs; 9% of which showed visible tinea symptoms. The majority was identified as asymptomatic carriers of the dermatophyte. Pet shop guinea pigs have a high risk of being carriers of T. benhamiae, which can be transmitted to humans via physical contact, even though there is no visible infection in most cases. It is therefore recommended to have newly purchased animals examined by a veterinarian.

  14. Using guinea pigs in studies relevant to asthma and COPD

    PubMed Central

    Canning, Brendan J.; Chou, Yangling

    2010-01-01

    The guinea pig has been the most commonly used small animal species in preclinical studies related to asthma and COPD. The primary advantages of the guinea pig are the similar potencies and efficacies of agonists and antagonists in human and guinea pig airways and the many similarities in physiological processes, especially airway autonomic control and the response to allergen. The primary disadvantages to using guinea pigs are the lack of transgenic methods, limited numbers of guinea pig strains for comparative studies and a prominent axon reflex that is unlikely to be present in human airways. These attributes and various models developed in guinea pigs are discussed. PMID:18462968

  15. Expression of the secreted FAD-dependent sulfydryl oxidase (QSOX) in the guinea pig central nervous system.

    PubMed

    Amiot, C; Musard, J F; Hadjiyiassemis, M; Jouvenot, M; Fellmann, D; Risold, P Y; Adami, P

    2004-06-18

    cpQSOx1 is a member of the QSOx family of proteins, expressed in the guinea pig (Cavia porcellus) and ortholog of the rat rQSOx1. In this study, in vitro experiments were conducted and showed that, as other member of this family, cpQSOx1 has a sulfydryl oxidase activity, and is a secreted protein. Then, the expression of this enzyme was researched in the guinea pig brain, as very little information exists yet on the expression of QSOx family members in the central nervous system. By immunohistochemistry, RT-PCR and in situ hybridization, cpQSOx1 is synthesized by neurons throughout the whole guinea pig central nervous system. Reticular structures as the basal forebrain, reticular thalamic nucleus and reticular nuclei of the brainstem contained the densest labeling. These results are discussed in terms of putative roles of this protein in synaptic strengthening and in redox activities.

  16. Development of isolation-induced vocal behavior in normal-hearing and deafened guinea pig infants.

    PubMed

    Arch-Tirado, E; McCowan, B; Saltijeral-Oaxaca, J; Zarco de Coronado, I; Licona-Bonilla, J

    2000-04-01

    Infants in many different animal species require auditory information from conspecifics to learn appropriate responses to important environmental and social cues. Isolation calls are emitted by infant guinea pigs in contexts of social separation from their mothers. The aim of the present study was to examine the ontogeny of the isolation calls in normal-hearing and deafened infant guinea pigs, from 2 to 40 days postpartum and to determine the role of hearing maternal vocalization in infant guinea pig vocal responses in contexts of social proximity and isolation. Female newborn pigmented guinea pigs (Cavia porcellus) were housed with their birth mother and siblings. Water and dry food were available ad libitum. One day postpartum, the cochlea of infants in the experimental group was destroyed. The control group consisted of normal-hearing female siblings. Vocalizations from infants in the experimental and control groups were recorded for 6 minutes when with the mother before isolation, 6 minutes when alone, and then 6 minutes when with the mother after reunion. Recordings were made 5 days per week from 2 to 40 days after birth. The duration of calling was calculated for each 6-minute period of recording. Results demonstrated that deaf infants vocalize more than normal-hearing infants during social isolation from their mothers. Vocal activity of isolated deaf and normal-hearing infants decreased substantially over development, almost disappearing by the end of the study period. These results indicate that maternal vocal behavior modulates the vocal responses of guinea pigs early in infant development and supports other evidence that the guinea pig offers a viable model for investigating audition in deaf and normal-hearing human infants.

  17. Temporal Progression of Lesions in Guinea Pigs Infected With Lassa Virus.

    PubMed

    Bell, T M; Shaia, C I; Bearss, J J; Mattix, M E; Koistinen, K A; Honnold, S P; Zeng, X; Blancett, C D; Donnelly, G C; Shamblin, J D; Wilkinson, E R; Cashman, K A

    2017-05-01

    Lassa virus (LASV) infection causes an acute, multisystemic viral hemorrhagic fever that annually infects an estimated 100 000 to 300 000 persons in West Africa. This pathogenesis study evaluated the temporal progression of disease in guinea pigs following aerosol and subcutaneous inoculation of the Josiah strain of LASV as well as the usefulness of Strain 13 guinea pigs as an animal model for Lassa fever. After experimental infection, guinea pigs ( Cavia porcellus; n = 67) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and serum chemistry and hematologic changes. Guinea pigs developed viremia on day 5 to 6 postexposure (PE), with clinical signs appearing by day 7 to 8 PE. Complete blood counts revealed lymphopenia and thrombocytopenia. Gross pathologic findings included skin lesions and congested lungs. Histologic lesions consisted of cortical lymphoid depletion by day 6 to 7 PE with lymphohistiocytic interstitial pneumonia at 7 to 8 days PE. Scattered hepatocellular degeneration and cell death were also noted in the liver and, to a lesser extent, in other tissues including the haired skin, lung, heart, adrenal gland, lymph nodes, thymus, and spleen. The first cell types to demonstrate staining for viral antigen were fibroblastic reticular cells and macrophages/dendritic cells in the lymph nodes on day 5 to 6 PE. This study demonstrates similarities between Lassa viral disease in human infections and experimental guinea pig infection. These shared pathologic characteristics support the utility of guinea pigs as an additional animal model for vaccine and therapeutic development under the Food and Drug Administration's Animal Rule.

  18. Streptomycin action to the mammalian inner ear vestibular organs: comparison between pigmented guinea pigs and rats.

    PubMed

    Meza, Graciela; Aguilar-Maldonado, Beatriz

    2007-01-01

    Streptomycin is the antibiotic of choice to treat tuberculosis and other infectious diseases but it causes vestibular malfunction and hipoacusia. Rodents are usually employed as models of drug action to the inner ear and results are extrapolated to what happens in humans. In rats, streptomycin destroys macular sensory cells and does not affect cochlear ones, whereas in guinea pigs the contrary is true. Action on the vestibular cristae cells involved in vestibulo-ocular reflex integrity is less clear. Thus, we compared this response in both pigmented guinea pigs (Cavia cobaya) and rats (Rattus norvegicus) after parallel streptomycin chronic treatment. In guinea pigs, the reflex was obliterated along treatment time; in rats this behavior was not observed, suggesting that the end organ target was diverse. In recent studies, streptidine, a streptomycin derivative found in the blood of humans and rats treated with streptomycin, was the actual ototoxic agent. The putative streptomycin vestibular organ target observed in humans corresponds with the guinea pig observations. Results observed in rats are controversial: streptidine did not cause any damage either to vestibular cristae nor auditory cells. We hypothesize differential drug metabolism and distribution and conclude that results in laboratory animals may not always be applicable in the human situation.

  19. Infectious dose and repeated infections are key factors influencing immune response characteristics in guinea pig ocular chlamydial infection.

    PubMed

    Belij-Rammerstorfer, Sandra; Inic-Kanada, Aleksandra; Stojanovic, Marijana; Marinkovic, Emilija; Lukic, Ivana; Stein, Elisabeth; Montanaro, Jacqueline; Bintner, Nora; Schürer, Nadine; Ghasemian, Ehsan; Kundi, Michael; Barisani-Asenbauer, Talin

    2016-04-01

    The aim of this study was to determine whether infectious dose of Chlamydia caviae after repeated infections influences the immunological responses and subsequent clearance of pathogen at the ocular surface of guinea pigs. Animals were infected three times via the conjunctiva at six- and twelve-week intervals by applying either 1 × 10(4) or 1 × 10(6) inclusion-forming units (IFUs) of C. caviae. Ocular pathology, infection course, C. caviae-specific serum IgG levels and their capacity to bind and neutralize infection ex vivo were assessed. Animals infected with 1 × 10(4) IFUs had completely diminished ocular infection and pathology after the 2nd infection with increased levels of C. caviae-specific serum IgG and their effective capacity to bind and neutralize C. caviae. Only partial protection was observed in animals infected with 1 × 10(6) IFUs after the 2nd and 3rd infections. Our findings show that full protection was observed in animals repeatedly infected with the lower dose. The lower dose appeared not to compromise the host immune system, thereby enabling fast clearance of the pathogen and the establishment of competent neutralizing antibodies.

  20. Influenza virus infection in guinea pigs raised as livestock, Ecuador.

    PubMed

    Leyva-Grado, Victor H; Mubareka, Samira; Krammer, Florian; Cárdenas, Washington B; Palese, Peter

    2012-07-01

    To determine whether guinea pigs are infected with influenza virus in nature, we conducted a serologic study in domestic guinea pigs in Ecuador. Detection of antibodies against influenza A and B raises the question about the role of guinea pigs in the ecology and epidemiology of influenza virus in the region.

  1. Malignant transformation of guinea pig cells after exposure to ultraviolet-irradiated guinea pig cytomegalovirus

    SciTech Connect

    Isom, H.C.; Mummaw, J.; Kreider, J.W.

    1983-04-30

    Guinea pig cells were malignantly transformed in vitro by ultraviolet (uv)-irradiated guinea pig cytomegalovirus (GPCMV). When guinea pig hepatocyte monolayers were infected with uv-irradiated GPCMV, three continuous epithelioid cell lines which grew in soft agarose were established. Two independently derived GPCMV-transformed liver cells and a cell line derived from a soft agarose clone of one of these lines induced invasive tumors when inoculated subcutaneously or intraperitoneally into nude mice. The tumors were sarcomas possibly derived from hepatic stroma or sinusoid. Transformed cell lines were also established after infection of guinea pig hepatocyte monolayers with human cytomegalovirus (HCMV) or simian virus 40 (SV40). These cell lines also formed colonies in soft agarose and induced sarcomas in nude mice. It is concluded that (i) GPCMV can malignantly transform guinea pig cells; (ii) cloning of GPCMV-transformed cells in soft agarose produced cells that induced tumors with a shorter latency period but with no alteration in growth rate or final tumor size; and (iii) the tumors produced by GPCMV-and HCMV-transformed guinea pig cells were more similar to each other in growth rate than to those induced by SV40-transformed guinea pig cells.

  2. [Tooth regeneration in the guinea pig (Cavia porcellus)].

    PubMed

    Stephan, F; Artis, J P; Lanot, R

    1977-01-01

    The first inferior molar has been extracted, a part of its being reimplanted or not. A new molar of normal form regenerated, apparently from the apex of the tooth germ, in all cases in which the alveolus was left free or implanted with a tooth freagment deprived of pulpa.

  3. Skin toxicity of propranolol in guinea pigs.

    PubMed

    Kobayashi, I; Hosaka, K; Maruo, H; Saeki, Y; Kamiyama, M; Konno, C; Gemba, M

    1999-05-01

    The skin toxicities of propranolol were studied in guinea pigs. In the primary and cumulative skin irritation studies, the skin reactions and the histopathological changes were observed in all animals treated with propranolol, and those tended to increase with the increase of propranolol dosage. The skin reactions increased with the application times of propranolol up to 7 days in the cumulative skin irritation study. In the skin sensitization, the phototoxicity and the skin photosensitization studies, no skin reactions were observed in any animals used in the studies. These results indicate that propranolol caused skin irritation, but was negative for skin sensitization, phototoxicity and skin photosensitization in guinea pigs.

  4. ECG telemetry in conscious guinea pigs.

    PubMed

    Ruppert, Sabine; Vormberge, Thomas; Igl, Bernd-Wolfgang; Hoffmann, Michael

    2016-01-01

    During preclinical drug development, monitoring of the electrocardiogram (ECG) is an important part of cardiac safety assessment. To detect potential pro-arrhythmic liabilities of a drug candidate and for internal decision-making during early stage drug development an in vivo model in small animals with translatability to human cardiac function is required. Over the last years, modifications/improvements regarding animal housing, ECG electrode placement, and data evaluation have been introduced into an established model for ECG recordings using telemetry in conscious, freely moving guinea pigs. Pharmacological validation using selected reference compounds affecting different mechanisms relevant for cardiac electrophysiology (quinidine, flecainide, atenolol, dl-sotalol, dofetilide, nifedipine, moxifloxacin) was conducted and findings were compared with results obtained in telemetered Beagle dogs. Under standardized conditions, reliable ECG data with low variability allowing largely automated evaluation were obtained from the telemetered guinea pig model. The model is sensitive to compounds blocking cardiac sodium channels, hERG K(+) channels and calcium channels, and appears to be even more sensitive to β-blockers as observed in dogs at rest. QT interval correction according to Bazett and Sarma appears to be appropriate methods in conscious guinea pigs. Overall, the telemetered guinea pig is a suitable model for the conduct of early stage preclinical ECG assessment. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. New guinea pig model of Cryptococcal meningitis.

    PubMed

    Kirkpatrick, William R; Najvar, Laura K; Bocanegra, Rosie; Patterson, Thomas F; Graybill, John R

    2007-08-01

    We developed a guinea pig model of cryptococcal meningitis to evaluate antifungal agents. Immunosuppressed animals challenged intracranially with Cryptococcus neoformans responded to fluconazole and voriconazole. Disease was monitored by serial cerebrospinal fluid (CSF) cultures and quantitative organ cultures. Our model produces disseminating central nervous system disease and responds to antifungal therapy.

  6. Arrangement of Renal Arteries in Guinea Pig.

    PubMed

    Mazensky, David; Flesarova, Slavka

    2017-03-01

    The aim of this study was to describe origin, localization, and variations of renal arteries in guinea pig. The study was carried out on 26 adult guinea pigs. We prepared corrosion casts of the guinea pig arterial system. Batson's corrosion casting kit no. 17 was used as the casting medium. In 57.7% of specimens, a. renalis dextra was present as a single vessel with different level of its origin from aorta abdominalis. In 38.5% of specimens, two aa. renales dextrae were present with variable origin and arrangement. The presence of three aa. renales dextrae we found in one specimen. In 76.9% of specimens, a. renalis sinistra was present as a single vessel with different level of its origin from aorta abdominalis and variable arrangement. In 23.1% of specimens, we found two aa. renales sinistrae with variable origin and arrangement. The anatomical knowledge of the renal arteries, and its variations are of extreme importance for the surgeon that approaches the retroperitoneal region in several experiments, results of which are extrapolated in human. This is the first work dealing with the description of renal arteries arrangement in guinea pig. Anat Rec, 300:556-559, 2017. © 2016 Wiley Periodicals, Inc.

  7. Watch out guinea pigs, here I come.

    PubMed

    Norton, T

    2001-04-01

    We live in an age of increasing emphasis of do-it-yourself, as a mere glance at the TV schedule will prove. Why not apply this same principle to your research? By becoming the guinea pig of your own experimentation you will be following a noble precedent--though maybe not a sane one!

  8. Immune modulation in the guinea pig using cortisone acetate.

    PubMed

    Scipioni, R L; Baggs, R B; Kraus, A L

    1991-01-01

    Cortisone acetate was administered to a group of guinea pigs (Cavia porcellus) at 0 (control), 20 (low) or 200 (high) mg/kg. Steroid was given daily for two individual 7 day periods, separated by 7 days of no treatment. The effects of this steroid on body weight gain, thymic weight, total and differential leukocyte counts, serum antibody titer against a bacterin, dermal hypersensitivity response to a sensitizing agent and histological evaluation of lymphoid and other tissues were evaluated. Significant differences in body weight gain (p less than 0.05) and thymic weight (p less than .01) were noted. For total leukocyte count, no significant difference among treatment groups at individual time points was noted (p greater than .10), while significant differences were seen in lymphocyte and neutrophil counts (p less than .01). A significant difference in antibody titer among the treatment groups was observed (p less than .01). For the dermal hypersensitivity response, there was no consistent pattern among the treatment groups in gross (macroscopic) skin reactions. Microscopically, differences were seen in the inflammatory response among the treatment groups. Histologically, steroid related changes were seen in thymus, spleen, lymph node and liver. At necropsy, 24 of 40 animals had lesions of focal necrotizing hepatitis. Three affected animals died and remaining animals showed no clinical illness. The cause of the necrotizing hepatitis could not be determined by culture, special stains, electron microscopy, serology or by attempts at transmission with affected liver samples.

  9. Synthesis of factor VIII antigen by cultured guinea pig megakaryocytes.

    PubMed

    Nachman, R; Levine, R; Jaffe, E A

    1977-10-01

    Immunoprecipitates containing guinea pig Factor VIII antigen were prepared from guinea pig plasma with a cross-reacting rabbit anti-human Factor VIII. Monospecific antisera to guinea pig Factor VIII antigen were produced in rabbits by using these washed immunoprecipitates as immunogens. The resulting antisera to guinea pig Factor VIII antigen detected Factor VIII antigen in guinea pig plasma and inhibited the von Willebrand factor activity in guinea pig plasma. This antibody also detected Factor VIII antigen in a solubilized protein mixture prepared from isolated cultured guinea pig megakaryocytes. Cultured guinea pig megakaryocytes were labeled with radio-active leucine. By radioautography, 96.2% of the radio-activity was present in megakaryocytes. The radio-active Factor VIII antigen present in the solubilized cell protein mixture was isolated by immunoprecipitation and characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results demonstrate that cultured guinea pig megakaryocytes synthesize Factor VIII antigen which contains the same polypeptide subunit (mol wt 200,000) present in guinea pig plasma Factor VIII antigen.

  10. Whole genome sequencing and methylome analysis of the wild guinea pig.

    PubMed

    Weyrich, Alexandra; Schüllermann, Tino; Heeger, Felix; Jeschek, Marie; Mazzoni, Camila J; Chen, Wei; Schumann, Kathrin; Fickel, Joerns

    2014-11-28

    DNA methylation is a heritable mechanism that acts in response to environmental changes, lifestyle and diseases by influencing gene expression in eukaryotes. Epigenetic studies of wild organisms are mandatory to understand their role in e.g. adaptational processes in the great variety of ecological niches. However, strategies to address those questions on a methylome scale are widely missing. In this study we present such a strategy and describe a whole genome sequence and methylome analysis of the wild guinea pig. We generated a full Wild guinea pig (Cavia aperea) genome sequence with enhanced coverage of methylated regions, benefiting from the available sequence of the domesticated relative Cavia porcellus. This new genome sequence was then used as reference to map the sequence reads of bisulfite treated Wild guinea pig sequencing libraries to investigate DNA-methylation patterns at nucleotide-specific level, by using our here described method, named 'DNA-enrichment-bisulfite-sequencing' (MEBS). The results achieved using MEBS matched those of standard methods in other mammalian model species. The technique is cost efficient, and incorporates both methylation enrichment results and a nucleotide-specific resolution even without a whole genome sequence available. Thus MEBS can be easily applied to extend methylation enrichment studies to a nucleotide-specific level. The approach is suited to study methylomes of not yet sequenced mammals at single nucleotide resolution. The strategy is transferable to other mammalian species by applying the nuclear genome sequence of a close relative. It is therefore of interest for studies on a variety of wild species trying to answer evolutionary, adaptational, ecological or medical questions by epigenetic mechanisms.

  11. Computed tomography analysis of guinea pig bone: architecture, bone thickness and dimensions throughout development

    PubMed Central

    Witkowska, Agata; Alibhai, Aziza; Hughes, Chloe; Price, Jennifer; Klisch, Karl; Sturrock, Craig J.

    2014-01-01

    The domestic guinea pig, Cavia aperea f. porcellus, belongs to the Caviidae family of rodents. It is an important species as a pet, a source of food and in medical research. Adult weight is achieved at 8–12 months and life expectancy is ∼5–6 years. Our aim was to map bone local thickness, structure and dimensions across developmental stages in the normal animal. Guinea pigs (n = 23) that had died of natural causes were collected and the bones manually extracted and cleaned. Institutional ethical permission was given under the UK Home Office guidelines and the Veterinary Surgeons Act. X-ray Micro Computed Tomography (microCT) was undertaken on the left and right scapula, humerus and femur from each animal to ascertain bone local thickness. Images were also used to undertake manual and automated bone measurements, volumes and surface areas, identify and describe nutrient, supratrochlear and supracondylar foramina. Statistical analysis between groups was carried out using ANOVA with post-hoc testing. Our data mapped a number of dimensions, and mean and maximum bone thickness of the scapula, humerus and femur in guinea pigs aged 0–1 month, 1–3 months, 3–6 months, 6 months–1 year and 1–4 years. Bone dimensions, growth rates and local bone thicknesses differed between ages and between the scapula, humerus and femur. The microCT and imaging software technology showed very distinct differences between the relative local bone thickness across the structure of the bones. Only one bone showed a singular nutrient foramen, every other bone had between 2 and 5, and every nutrient canal ran in an oblique direction. In contrast to other species, a supratrochlear foramen was observed in every humerus whereas the supracondylar foramen was always absent. Our data showed the bone local thickness, bone structure and measurements of guinea pig bones from birth to 4 years old. Importantly it showed that bone development continued after 1 year, the point at which most

  12. Spontaneous reproductive pathology in female guinea pigs.

    PubMed

    Veiga-Parga, Tamara; La Perle, Krista M D; Newman, Shelley J

    2016-11-01

    Reproductive pathology of domestic guinea pigs is underreported to date. To provide a comprehensive review of uterine disease in guinea pigs, we performed a retrospective study of the pathology archives of the University of Tennessee, College of Veterinary Medicine. By histology, 13 of 37 uterine lesions in 23 animals were neoplastic; the other 24 nonneoplastic lesions included cystic endometrial hyperplasia (16 of 24), endometrial hemorrhage (3 of 24), pyometra (2 of 24), polyp (2 of 24), and mucometra (1 of 24). The most common guinea pig uterine neoplasms were uterine leiomyomas (6 of 13), followed by adenomas (3 of 13) and leiomyosarcomas (1 of 13). Other neoplasms included anaplastic tumors of unknown origin (2 of 13) and choriocarcinoma (1 of 13). Both anaplastic tumors and the choriocarcinoma were positive for vimentin. The choriocarcinoma was positive for HSD83B1, indicating a trophoblastic origin and its final diagnosis. All were negative for cytokeratin and smooth muscle. In multiple animals, more than 1 tumor or lesion was reported. Estrogen receptor and progesterone receptor expression was nearly 100% in uterine neoplasms. Nearly all animals for which data were available had cystic rete ovarii (18 of 19); the animal with no cystic rete ovarii had paraovarian cysts. In our study, female pet guinea pigs had a tendency to develop cystic endometrial hyperplasia and uterine neoplasia. Factors for the development of these lesions could be cystic rete ovarii, hormone dysregulation, and/or age. Other factors could contribute to the development of uterine lesions. As in other species, early ovariohysterectomy could decrease the prevalence of uterine lesions. © 2016 The Author(s).

  13. Naturally acquired infections with Leishmania enriettii Muniz and Medina 1948 in guinea-pigs from São Paulo, Brazil.

    PubMed

    Machado, M I; Milder, R V; Pacheco, R S; Silva, M; Braga, R R; Lainson, R

    1994-08-01

    Two domestic guinea-pigs (Cavia porcellus), bought in Pinheros, São Paulo State, Brazil, were taken by their owners to a farm in the rural district of Capão Bonito, close to the Atlantic Forest, São Paulo, where they both developed tumour-like and ulcerating lesions on the ears. The causative agent was identified as Leishmania (L.) enriettii, based on biological characters and isoenzyme profiles. Sources of the parasite in wild mammals, and the possible sandfly vector species are discussed.

  14. [Respiration at high altitudes, phosphate-protein interaction: the sequence of hemoglobins from guinea pig and dromedary (author's transl)].

    PubMed

    Braunitzer, G; Schrank, B; Stangl, A; Wiesner, H

    1979-12-01

    The sequence of the main hemoglobin component of the guinea pig (Cavia aerea f. porcellus, Caviidae) and that of the hemoglobin of the dromedary (Camelus dromedarius, Camelidae) is given. The sequence is obtained automatically by the sequenator using the quadrol and the propyne programme. The sequence of the alpha-and beta-chains of the guinea pig is compared with that of the human hemoglobin; the sequence of the dromedary in comparison to the Ilama shows in the alpha-chains five amino acid exchanges, in the beta-chains there are only two exchanges in beta 2 and beta 76. Beta 2 in dromedary is the P2-glycerate contact histidine. This sustains the interpretation of the high altitude respiration of the Ilama as mutation beta2His leads to Asn.

  15. The Guinea Pigs of a Problem-Based Learning Curriculum

    ERIC Educational Resources Information Center

    Reddy, Sarasvathie; McKenna, Sioux

    2016-01-01

    Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as "Guinea pigs" at the mercy of a curriculum experiment. This article interrogates and problematises the "Guinea pig" identity ascribed to and assumed by the first cohort of…

  16. Heterogeneous infectiousness in guinea pigs experimentally infected with Trypanosoma cruzi.

    PubMed

    Castillo-Neyra, Ricardo; Borrini Mayorí, Katty; Salazar Sánchez, Renzo; Ancca Suarez, Jenny; Xie, Sherrie; Náquira Velarde, Cesar; Levy, Michael Z

    2016-02-01

    Guinea pigs are important reservoirs of Trypanosoma cruzi, the causative parasite of Chagas disease, and in the Southern Cone of South America, transmission is mediated mainly by the vector Triatoma infestans. Interestingly, colonies of Triatoma infestans captured from guinea pig corrals sporadically have infection prevalence rates above 80%. Such high values are not consistent with the relatively short 7-8 week parasitemic period that has been reported for guinea pigs in the literature. We experimentally measured the infectious periods of a group of T. cruzi-infected guinea pigs by performing xenodiagnosis and direct microscopy each week for one year. Another group of infected guinea pigs received only direct microscopy to control for the effect that inoculation by triatomine saliva may have on parasitemia in the host. We observed infectious periods longer than those previously reported in a number of guinea pigs from both the xenodiagnosis and control groups. While some guinea pigs were infectious for a short time, other "super-shedders" were parasitemic up to 22 weeks after infection, and/or positive by xenodiagnosis for a year after infection. This heterogeneity in infectiousness has strong implications for T. cruzi transmission dynamics and control, as super-shedder guinea pigs may play a disproportionate role in pathogen spread. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. A 2-D guinea pig lung proteome map

    USDA-ARS?s Scientific Manuscript database

    Guinea pigs represent an important model for a number of infectious and non-infectious pulmonary diseases. The guinea pig genome has recently been sequenced to full coverage, opening up new research avenues using genomics, transcriptomics and proteomics techniques in this species. In order to furth...

  18. The Guinea Pigs of a Problem-Based Learning Curriculum

    ERIC Educational Resources Information Center

    Reddy, Sarasvathie; McKenna, Sioux

    2016-01-01

    Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as "Guinea pigs" at the mercy of a curriculum experiment. This article interrogates and problematises the "Guinea pig" identity ascribed to and assumed by the first cohort of…

  19. Streptococcus equi subsp. zooepidemicus Infections Associated with Guinea Pigs

    PubMed Central

    Young, Andrea; Levine, Seth J.; Garvin, Joseph P.; Brown, Susan; Turner, Lauren; Fritzinger, Angela; Gertz, Robert E.; Murphy, Julia M.; Vogt, Marshall; Beall, Bernard

    2015-01-01

    Streptococcus equi subsp. zooepidemicus is a known zoonotic pathogen. In this public health investigation conducted in Virginia, USA, in 2013, we identified a probable family cluster of S. zooepidemicus cases linked epidemiologically and genetically to infected guinea pigs. S. zooepidemicus infections should be considered in patients who have severe clinical illness and report guinea pig exposure. PMID:25531424

  20. Of Domestic and Wild Guinea Pigs: Studies in Sociophysiology, Domestication, and Social Evolution

    NASA Astrophysics Data System (ADS)

    Sachser, Norbert

    Among mammals a majority of each individual's daily expectations, motivations, and behaviors are directed to encounters with conspecifics. Therefore the knowledge of the genesis, control, and consequences of social interactions is crucial for understanding their social life. We present here our research on the sociophysiology, domestication, and social evolution of wild (Cavia aperea and Galea musteloides) and domestic (Cavia aperea f. porcellus) guinea pigs, which summarizes general rules for many group-living mammals. It is shown that social interactions have consequences not only for the individuals' reproductive success but also for their degrees of stress and welfare. The way in which individuals interact is controlled not only by the present environment but also by the previous social experiences which they have gathered during their behavioral development. Furthermore, the study of ontogeny does not begin at birth, because prenatal social factors acting on pregnant females can also affect the way in which the offspring will interact when adult. In addition, to understand the genesis of interactions between domesticated animals implies knowledge of the behavioral and physiological changes which occurred during the process of domestication. Finally, understanding the social interactions among individuals of the wild ancestor of the domesticated form requires knowledge of how their behavior patterns were brought about by natural selection during the process of social evolution.

  1. Ebola virus transmission in guinea pigs.

    PubMed

    Wong, Gary; Qiu, Xiangguo; Richardson, Jason S; Cutts, Todd; Collignon, Brad; Gren, Jason; Aviles, Jenna; Embury-Hyatt, Carissa; Kobinger, Gary P

    2015-01-15

    Ebola virus (EBOV) transmission is currently poorly characterized and is thought to occur primarily by direct contact with infectious material; however transmission from swine to nonhuman primates via the respiratory tract has been documented. To establish an EBOV transmission model for performing studies with statistical significance, groups of six guinea pigs (gps) were challenged intranasally (i.n.) or intraperitoneally (i.p.) with 10,000 times the 50% lethal dose (LD50) of gp-adapted EBOV, and naive gps were then introduced as cage mates for contact exposure at 1 day postinfection (p.i.). The animals were monitored for survival and clinical signs of disease and quantitated for virus shedding postexposure. Changes in the duration of contact of naive gps with infected animals were evaluated for their impact on transmission efficiency. Transmission was more efficient from i.n.- than from i.p.-challenged gps, with 17% versus 83% of naive gps surviving exposure, respectively. Virus shedding was detected beginning at 3 days p.i. from both i.n.- and i.p.-challenged animals. Contact duration positively correlated with transmission efficiency, and the abrogation of direct contact between infected and naive animals through the erection of a steel mesh was effective at stopping virus spread, provided that infectious animal bedding was absent from the cages. Histopathological and immunohistochemical findings show that i.n.-infected gps display enhanced lung pathology and EBOV antigen in the trachea, which supports increased virus transmission from these animals. The results suggest that i.n.-challenged gps are more infectious to naive animals than their systemically infected counterparts and that transmission occurs through direct contact with infectious materials, including those transported through air movement over short distances. Ebola is generally thought to be spread between humans though infectious bodily fluids. However, a study has shown that Ebola can be spread

  2. Pathogenesis of Lassa Virus Infection in Guinea Pigs

    DTIC Science & Technology

    1982-08-01

    INFECTION AND IMMUNITY. Aug. 1982. p. 771-778 Vol. 37. No. 2 0019-9567/82/080771-08$02.00/0 Pathogenesis of Lassa Virus Infection in Guinea Pigs... virus strain Josiah. In contrast, no more than 30% of the Hartley guinea pigs died regardless of the virus rdose. In lethally infected strain 13 guinea...pigs, peak titers of virus (107 to 10 PFU) occurred in the spleen and lymph nodes at 8 to 9 days, in the salivary glands at 11 days, and in the lung at

  3. Zeta-crystallin, a novel lens protein from the guinea pig.

    PubMed

    Huang, Q L; Russell, P; Stone, S H; Zigler, J S

    1987-05-01

    Lens proteins from the guinea pig (Cavia porcellus) were found to be similar to those of other mammals with the exception of the presence of a previously undescribed constituent comprising about 10% of the total soluble lens proteins. This oligomeric protein is composed of polypeptides with apparent molecular weight of 38,000 and elutes from gel exclusion chromatography columns in the beta H-crystallin fraction. Following purification by ion exchange chromatography an antibody was raised against the protein. Using that antibody and antibodies specific for other crystallins we could detect no cross-reactivity between the guinea pig protein and any other reported lens crystallin. This protein, which we have named zeta (zeta)-crystallin, is the first reported mammalian lens crystallin which is not part of the alpha- or beta-gamma families of crystallins. Unlike all other known mammalian crystallins, which have little or no alpha-helical structure, zeta-crystallin is estimated to be approximately 30-40% alpha-helix.

  4. Evaluation of experimental methods to induce congenital hypothyroidism in guinea pigs for use in the study of congenital hypothyroidism in horses.

    PubMed

    D'Amours, Geneviève H; Taylor, Susan M; Olfert, Ernest D; Simko, Elemir; Allen, Andrew L

    2004-09-01

    To develop a method to reliably induce congenital hypothyroidism in guinea pigs (Cavia porcellus) and assess similarities between the resultant developmental abnormalities and those described in horses with congenital hypothyroidism. 35 female guinea pigs and their offspring. Guinea pigs were allocated to control groups or groups treated with a low-iodine diet before and throughout gestation; an s.c. injection of 100 or 200 microCi of radioactive iodine 131 (131I) on day 40 of gestation; or 0.1% propylthiouracil (PTU) continuously in the drinking water, beginning day 3 or 40 of gestation. In all groups, assessments included gestation duration, litter size, proportion of stillborn pups, and laboratory analyses in live pups and dams; postmortem examinations were performed on all pups and dams and selected tissues were examined histologically. Compared with control animals, pups from dams receiving a low-iodine diet or 131I s.c. had mild changes in their thyroid glands but no grossly or radiographically detectable lesions of hypothyroidism. Pups from dams receiving PTU were often stillborn (24/27 pups) and had enlarged thyroid glands (characterized by large, variably sized follicles of tall columnar epithelium and little or no colloid), an incomplete coat, and radiographically detectable skeletal dysgenesis. Many of the lesions detected in guinea pig pups from the experimentally treated dams were similar to those described in foals with congenital hypothyroidism. Experimental induction of congenital hypothyroidism in guinea pigs may be useful for the study of naturally occurring congenital hypothyroidism in horses.

  5. The effect of infectious dose on humoral and cellular immune responses in Chlamydophila caviae primary ocular infection

    PubMed Central

    Inic-Kanada, Aleksandra; Lukic, Ivana; Stein, Elisabeth; Marinkovic, Emilija; Djokic, Radmila; Kosanovic, Dejana; Schuerer, Nadine; Chalabi, Hadeel; Belij-Rammerstorfer, Sandra; Stojanovic, Marijana

    2017-01-01

    Following infection, the balance between protective immunity and immunopathology often depends on the initial infectious load. Several studies have investigated the effect of infectious dose; however, the mechanism by which infectious dose affects disease outcomes and the development of a protective immune response is not known. The aim of this study was to investigate how the infectious dose modulates the local and systemic humoral and the cellular immune responses during primary ocular chlamydial infection in the guinea pig animal model. Guinea pigs were infected by ocular instillation of a Chlamydophila caviae-containing eye solution in the conjunctival sac in three different doses: 1×102, 1×104, and 1×106 inclusion forming units (IFUs). Ocular pathology, chlamydial clearance, local and systemic C. caviae-specific humoral and cellular immune responses were assessed. All inocula of C. caviae significantly enhanced the local production of C. caviae-specific IgA in tears, but only guinea pigs infected with the higher doses showed significant changes in C. caviae-specific IgA levels in vaginal washes and serum. On complete resolution of infection, the low dose of C. caviae did not alter the ratio of CD4+ and CD8+ cells within guinea pigs’ submandibular lymph node (SMLN) lymphocytes while the higher doses increased the percentages of CD4+ and CD8+ cells within the SMLN lymphocytes. A significant negative correlation between pathology intensity and the percentage of CD4+ and CD8+ cells within SMLN lymphocyte pool at selected time points post-infection was recorded for both 1×104, and 1×106 IFU infected guinea pigs. The relevance of the observed dose-dependent differences on the immune response should be further investigated in repeated ocular chlamydial infections. PMID:28678871

  6. Determination of oxidative stress and activities of antioxidant enzymes in guinea pigs treated with haloperidol

    PubMed Central

    GUMULEC, JAROMIR; RAUDENSKA, MARTINA; HLAVNA, MARIAN; STRACINA, TIBOR; SZTALMACHOVA, MARKETA; TANHAUSEROVA, VERONIKA; PACAL, LUKAS; RUTTKAY-NEDECKY, BRANISLAV; SOCHOR, JIRI; ZITKA, ONDREJ; BABULA, PETR; ADAM, VOJTECH; KIZEK, RENE; NOVAKOVA, MARIE; MASARIK, MICHAL

    2013-01-01

    Guinea pigs (Cavia porcellus) were treated with haloperidol (HP), and free radical (FR) and ferric reducing antioxidant power (FRAP) assays were used to determine oxidative stress levels. Furthermore, the superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-S-transferase (GST) activity levels were detected and glucose levels and the reduced and oxidized glutathione (GSH/GSSG) ratio were measured in HP-treated and untreated guinea pigs. The present study demonstrated that the administration of HP causes significant oxidative stress in guinea pigs (P=0.022). In animals treated with HP, the activity of GST was significantly increased compared with a placebo (P= 0.007). The elevation of SOD and GR activity levels and increase in the levels of glutathione (GSH) in HP-treated animals were not statistically significant. In the HP-untreated animals, a significant positive correlation was observed between oxidative stress detected by the FR method and GST (r=0.88, P=0.008) and SOD (r=0.86, P= 0.01) activity levels, respectively. A significant negative correlation between the levels of plasma glucose and oxidative stress detected by the FRAP method was observed (r=−0.78, P=0.04). Notably, no significant correlations were observed in the treated animals. In the HP-treated group, two subgroups of animals were identified according to their responses to oxidative stress. The group with higher levels of plasma HP had higher enzyme activity and reactive oxygen species production compared with the group with lower plasma levels of HP. The greatest difference in activity (U/μl) between the two groups of animals was for GR. PMID:23403848

  7. Determination of oxidative stress and activities of antioxidant enzymes in guinea pigs treated with haloperidol.

    PubMed

    Gumulec, Jaromir; Raudenska, Martina; Hlavna, Marian; Stracina, Tibor; Sztalmachova, Marketa; Tanhauserova, Veronika; Pacal, Lukas; Ruttkay-Nedecky, Branislav; Sochor, Jiri; Zitka, Ondrej; Babula, Petr; Adam, Vojtech; Kizek, Rene; Novakova, Marie; Masarik, Michal

    2013-02-01

    Guinea pigs (Cavia porcellus) were treated with haloperidol (HP), and free radical (FR) and ferric reducing antioxidant power (FRAP) assays were used to determine oxidative stress levels. Furthermore, the superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-S-transferase (GST) activity levels were detected and glucose levels and the reduced and oxidized glutathione (GSH/GSSG) ratio were measured in HP-treated and untreated guinea pigs. The present study demonstrated that the administration of HP causes significant oxidative stress in guinea pigs (P=0.022). In animals treated with HP, the activity of GST was significantly increased compared with a placebo (P= 0.007). The elevation of SOD and GR activity levels and increase in the levels of glutathione (GSH) in HP-treated animals were not statistically significant. In the HP-untreated animals, a significant positive correlation was observed between oxidative stress detected by the FR method and GST (r=0.88, P=0.008) and SOD (r=0.86, P= 0.01) activity levels, respectively. A significant negative correlation between the levels of plasma glucose and oxidative stress detected by the FRAP method was observed (r=-0.78, P=0.04). Notably, no significant correlations were observed in the treated animals. In the HP-treated group, two subgroups of animals were identified according to their responses to oxidative stress. The group with higher levels of plasma HP had higher enzyme activity and reactive oxygen species production compared with the group with lower plasma levels of HP. The greatest difference in activity (U/μl) between the two groups of animals was for GR.

  8. A new assay system for guinea pig interferon biological activity.

    PubMed

    Yamamoto, Toshiko; Jeevan, Amminikutty; Ohishi, Kazue; Nojima, Yasuhiro; Umemori, Kiyoko; Yamamoto, Saburo; McMurray, David N

    2002-07-01

    We have developed an assay system for guinea pig interferon (IFN) based on reduction of viral cytopathic effect (CPE) in various cell lines. CPE inhibition was detected optimally in the guinea pig fibroblast cell line 104C1 infected with encephalomyocarditis virus (EMCV). The amount of biologically active guinea pig IFN was quantified by estimating viable cell numbers colorimetrically by means of a tetrazolium compound, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-1) and 1-methoxy-5-methylphenazinium methylsulfate (PMS). WST-1 color developed until stopped by the addition of sulfuric acid. This had no effect on the colorimetric assay, and the color was stable for at least 24 h. The acid also inactivated the EMCV and, thus, eliminated the viral hazard. Inhibition of CPE activity was highly correlated with the concentration of culture supernatants from BCG-vaccinated guinea pig splenocytes stimulated in vitro with tuberculin or an immunostimulatory oligoDNA. This assay detected guinea pig IFN and human IFN-alpha, but not IFN-gamma from human, mouse, rat, pig, or dog. This assay system has proved useful for the titration of guinea pig IFN, being easy to perform, free from viral hazard, relatively species specific, highly reproducible, and inexpensive.

  9. Radiation-induced micrencephaly in guinea pigs

    SciTech Connect

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1992-11-01

    The effect of x rays on brain weight of guinea pig pups at birth was studied for 21-day old embroys exposed in utero to doses of 75 and 100 mGy. When compared to controls and when corrected for body weight, gestation time, litter size, sex, and examiner differences the brains of irradiated pups weighed approximately 46 mg less than those of controls (p<0.001) for the 75-mGy group and about 55 mg less for the 100-mGy group. Brains of females weighed 51 mg less than those of males of the same body weight. Dam weight and caging conditions had no observed effect on brain weight.

  10. Radiation-induced micrencephaly in guinea pigs

    SciTech Connect

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1992-01-01

    The effect of x rays on brain weight of guinea pig pups at birth was studied for 21-day old embroys exposed in utero to doses of 75 and 100 mGy. When compared to controls and when corrected for body weight, gestation time, litter size, sex, and examiner differences the brains of irradiated pups weighed approximately 46 mg less than those of controls (p<0.001) for the 75-mGy group and about 55 mg less for the 100-mGy group. Brains of females weighed 51 mg less than those of males of the same body weight. Dam weight and caging conditions had no observed effect on brain weight.

  11. Reversing the objective: Adding guinea pig pedagogies

    NASA Astrophysics Data System (ADS)

    Weinstein, Matthew

    2004-03-01

    This article explores objectification in science and science education, i.e., the way material is turned into an object of interest to scientists. Drawing on sociological and anthropological drama theory, it examines how objectification does and does not occur in classrooms and schools. To understand the role and relationship of the object to the scientist, I look at current literature from the social studies of science concerning human and nonhuman objects as well as my own ethnographic work on the activism of politicized human research subjects. The paper concludes by how and why a more self-conscious focus on the object of science is important for those concerned with equity in science education, suggesting that such guinea pig pedagogies restore missing historical and ethical dimensions to science education.

  12. Transglutaminase from Hair Follicle of Guinea Pig

    PubMed Central

    Chung, S. I.; Folk, J. E.

    1972-01-01

    Two transglutaminases are found in homogenates of the inner root sheaths of guinea pig hair-follicles. One is indistinguishable from the well-characterized liver transglutaminase [J. Biol. Chem., 246, 1093 (1971)]. The other, which is present in far greater quantity, has not been detected in other organs or tissues. Gel filtration and polyacrylamide gel electrophoresis studies indicate that the native hair-follicle enzyme, of molecular weight 54,000, is composed of two subunits of identical molecular weight. Specificity studies suggest that the intermolecular cross-linking of fibrin and fibrinogen that is catalyzed by this enzyme is a result of the formation of ε(γ-glutamyl)lysine bonds. The probable participation of hair-follicle transglutaminase in the formation of these cross-links in the proteins of hair is discussed. Images PMID:4501114

  13. Electrocardiographic toxicity in the guinea pig.

    PubMed

    Lacroix, Pierre

    2002-11-01

    Abnormalities of cardiac rhythm are one of the most common clinical problems in cardiology and arise as the result of either disorders of cardiac impulse formation or conduction, or a combination of both. It has been established that some classes of drugs, such as tricyclic antidepressants (e.g., imipramine), cardiac glycosides (e.g., digoxin), and Class I or Class III antiarrhythmic drugs (e.g., quinidine or amiodarone) can produce electrocardiographic toxicity in humans. It is therefore highly advisable to assess the effect of any new compound in this respect, during the early phases of drug development. This unit presents a protocol to detect the electrocardiographic toxicity of compounds in the anesthetized guinea pig.

  14. Establishment of a Salmonella-Free Guinea Pig Colony

    PubMed Central

    Pivnick, Hilliard; Stuart, Philip F.; Walcroft, M.

    1966-01-01

    Salmonellosis due to Salmonella typhimurium was enzootic in a guinea pig breeding colony for over 25 years. A Salmonella-free auxiliary colony was established by removing weanlings from the infected colony to a clean area, and preventing infection. Examination of agglutinin titers and necropsy specimens indicated that the auxiliary colony was still free from Salmonella 18 months after its establishment while 24% of the guinea pigs dying in the infected colony yielded Salmonella typhimurium. PMID:17649571

  15. Antitussive effects of memantine in guinea pigs.

    PubMed

    Smith, Jaclyn A; Hilton, Emma C Y; Saulsberry, Loren; Canning, Brendan J

    2012-04-01

    The treatment of cough is a significant clinical unmet need because there is little evidence that current therapies are effective. Based on evidence supporting a role for N-methyl D-aspartate receptors (NMDARs) in cough, we hypothesized that memantine, a low-affinity, uncompetitive NMDAR channel blocker in routine use for the treatment of Alzheimer disease, could be an effective, well-tolerated, antitussive therapy. The aim of this study was to establish preclinical evidence that memantine has antitussive effects. We studied the influence of memantine on experimentally induced coughing in response to citric acid and bradykinin inhalation in guinea pigs. We also compared the potency and efficacy of memantine as an antitussive to other NMDAR antagonists, dextromethorphan and ketamine, and to the γ-aminobutyric acid class B receptor agonist baclofen. Compared with control subjects, 10 mg/kg memantine significantly reduced the cumulative number of coughs evoked by both citric acid (median, 24.0 [interquartile range (IQR), 13.0-25.5] vs 1.5 [IQR, 0.3-10.3] coughs; P = .012) and bradykinin aerosols (median, 16.0 [IQR, 9.5-18.5] vs 0.0 [IQR, 0-0.75] coughs; P = .002). Memantine 10 mg/kg produced a similar reduction in the cumulative number of coughs to baclofen 3 mg/kg and demonstrated comparatively greater cough suppression than 30 mg/kg dextromethorphan or 30 mg/kg ketamine. This dose of memantine produced no sedative or respiratory depressive effects. This study illustrates that memantine has marked antitussive effects in guinea pigs, most likely mediated through NMDAR channel blockade. Memantine, therefore, has the potential to be a safe, effective, and well-tolerated antitussive agent.

  16. The complementary deoxyribonucleic acid sequence of guinea pig endometrial prorelaxin.

    PubMed

    Lee, Y A; Bryant-Greenwood, G D; Mandel, M; Greenwood, F C

    1992-03-01

    The nucleotide sequence of the relaxin gene transcript in the endometrium of the late pregnant guinea pig has been determined. The strategy used was a combination of polymerase chain reaction (PCR) with primers designed from the mRNA sequence of porcine preprorelaxin, rapid amplification of cDNA ends-PCR, and blunt end cloning in M13 mp18. With heterologous primers, a 226-basepair (bp) segment of the guinea pig relaxin gene sequence was obtained and was used to design a guinea pig-specific primer for use with the rapid amplification of cDNA ends-PCR method. The latter allowed completion of the sequence of 336 bp, with a 96-bp overlap. The sequence obtained shows greater homology at both the nucleotide and amino acid levels with porcine and human relaxins H1 and H2 than with rat relaxin, supporting the thesis that the guinea pig is not a rodent. The transcription of the guinea pig endometrial relaxin gene during pregnancy was confirmed by Northern analysis of guinea pig endometrial tissues with a species-specific cDNA probe. The endometrial relaxin gene is transcribed during pregnancy, but not in lactation, consistent with the observed immunostaining for relaxin.

  17. [Experimental study of infectious hepatitis in guinea pigs].

    PubMed

    Asharafova, R A; Tuliaganov, P D; Kasymkhodzhaev, E S

    1976-04-01

    The authors carried out a comparative study of morphological changes in the liver of guinea-pigs in various times following intraperitoneal administration of the serum taken from a patient with infectious hepatitis (1st group), administration of the serum in combination with the urine (2nd group), administration of the serum in combination with the patient's duodenal juice (3rd group), and administration of the serum in combination with a hepatic antigen prepared of the liver of a healthy guinea-pig (4th group). Observations over the behaviour of the animals and morphological investigations showed a high sensitivity of guinea-pigs to virus-containing materials. The reaction was particularly pronounced in animals which were given the serum taken from a patient with infectious hepatitis in combination with a hepatic antigen, and the microscopic picture of the liver almost similar to that of the patient with Botkin's disease. Moreover, in the course of the study it was found possible to re-inoculate the virus obtained from the guinea-pigs subjected to a combined exposure to the serum from a patient with infectious hepatits and hepatic antigen. Comparing the results of the study on guinea-pigs with those obtained previously in the experimental study of viral hepatitis on white rats (1970), the authors have come to the conclusion that guinea-pigs may be used for modelling and experimental investigation of Botkin's disease.

  18. Radiation induced micrencephaly in guinea pigs

    SciTech Connect

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1991-01-01

    A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between radiation and small head size in humans at low doses as reported by Miller and Mulvihill. 16 refs., 13 tabs.

  19. Evaluation of Ebola Virus Countermeasures in Guinea Pigs.

    PubMed

    Marzi, Andrea

    2017-01-01

    Ebola virus (EBOV) pathology in humans remains incompletely understood; therefore, a number of rodent and nonhuman primate (NHP) models have been established to study the disease caused by this virus. While the macaque model most accurately recapitulates human disease, rodent models, which display only certain aspects of human disease but are more cost-effective, are widely used for initial screens during EBOV countermeasure development. In particular, mice and guinea pigs were among the first species used for the efficacy testing of EBOV vaccines and therapeutics. While mice have low predictive value, guinea pigs have proven to be a more reliable predictor for the evaluation of countermeasures in NHPs. In addition, guinea pigs are larger in size compared to mice, allowing for more frequent collection of blood samples at larger volumes. However, guinea pigs have the disadvantage that there is only a limited pool of immunological tools available to characterize host responses to vaccination, treatment and infection. In this chapter, the efficacy testing of an EBOV vaccine and a therapeutic in the guinea pig model are described.

  20. Hypervitaminosis D in Guinea Pigs with α-Mannosidosis

    PubMed Central

    Jensen, JanLee A; Brice, Angela K; Bagel, Jessica H; Mexas, Angela M; Yoon, Sea Young; Wolfe, John H

    2013-01-01

    A colony of guinea pigs (n = 9) with α-mannosidosis was fed a pelleted commercial laboratory guinea pig diet. Over 2 mo, all 9 guinea pigs unexpectedly showed anorexia and weight loss (11.7% to 30.0% of baseline weight), and 3 animals demonstrated transient polyuria and polydipsia. Blood chemistry panels in these 3 guinea pigs revealed high-normal total calcium, high-normal phosphate, and high ALP. Urine specific gravity was dilute (1.003, 1.009, 1.013) in the 3 animals tested. Postmortem examination of 7 animals that were euthanized after failing to respond to supportive care revealed renal interstitial fibrosis with tubular mineralization, soft tissue mineralization in multiple organs, hepatic lipidosis, and pneumonia. Analysis of the pelleted diet revealed that it had been formulated with a vitamin D3 content of more than 150 times the normal concentration. Ionized calcium and 25-hydroxyvitamin D values were both high in serum saved from 2 euthanized animals, confirming the diagnosis of hypervitaminosis D. This report discusses the clinical signs, blood chemistry results, and gross and histologic findings of hypervitaminosis D in a colony of guinea pigs. When unexpected signs occur colony-wide, dietary differentials should be investigated at an early time point. PMID:23582422

  1. Pharmacologically Stimulated Pupil and Accommodative Changes in Guinea Pigs

    PubMed Central

    Ostrin, Lisa A.; Garcia, Mariana B.; Choh, Vivian; Wildsoet, Christine F.

    2014-01-01

    Purpose. The guinea pig is being used increasingly as a model of human myopia. As accommodation may influence the effects of manipulations used in experimental myopia models, understanding the accommodative ability of guinea pigs is important. Here, nonselective muscarinic agonists were used as pharmacological tools to study guinea pig accommodation. Methods. Measurements were made on 15 pigmented guinea pigs. For in vivo testing, animals were anesthetized and, following baseline measurements, 2% pilocarpine was applied topically. Measurements included A-scan ultrasonography, optical coherence tomography (OCT) imaging, corneal topography, and refraction. In vitro lens scanning experiments were performed using anterior segment preparations, with measurements before and during exposure to carbachol. Anterior segment structures were examined histologically and immunohistochemistry was done to characterize the muscarinic receptor subtypes present. Results. In vivo, pilocarpine induced a myopic shift in refractive error coupled to a small, but consistent decrease in anterior chamber depth (ACD), a smaller and more variable increase in lens thickness, and a decrease in pupil size. Lens thickness increases were short-lived (10 minutes), while ACD and pupil size decreased over 20 minutes. Corneal curvature was not significantly affected. Carbachol tested on anterior segment preparations in vitro was without effect on lens back vertex distance, but did stimulate pupil constriction. Immunohistochemistry indicated the presence of muscarinic receptor subtypes 1 to 5 in the iris and ciliary body. Conclusions. The observed pilocarpine-induced changes in ACD, lens thickness, and refraction are consistent with active accommodation in the guinea pig, through cholinergic muscarinic stimulation. PMID:25097245

  2. [Phototoxicity of Bergamot oil. Comparison between humans and guinea pigs].

    PubMed

    Girard, J; Unkovic, J; Delahayes, J; Lafille, C

    1979-01-01

    Phototoxicity of bergamot oil in solar simulating radiation (SSR greater than or equal to 290 nm) and in long ultraviolet radiation (LUV greater than or equal to 320 nm) has been compared by studying photoaugmentation of erythema in the guinea pig after 24 h and pigmentary photoaugmentation in man on the 8th day. The results show that a close relationship exists between guinea pig and human responses, with both radiations used, and that man seems to be slightly more sensitive to phototoxic effects of bergamot oil than the guinea pig. This difference of sensitivity necessarily implies the participation of UVA (320--400 nm) in the phototoxic reaction of bergamot oil with solar radiation. This UVA participation is particularly obvious in the guinea pig; in man, the results are less clear and a certain synergy of UVB rays (290--320 nm) may be involved in the phototoxic UVA-induced reaction of bergamot oil. Despite these slight differences, the erythematous reaction in the guinea pig appears to be a remarkable experimental model to show out potential phototoxic reactions of products containing psoralens in man.

  3. A guinea pig model of Zika virus infection.

    PubMed

    Kumar, Mukesh; Krause, Keeton K; Azouz, Francine; Nakano, Eileen; Nerurkar, Vivek R

    2017-04-11

    Animal models are critical to understand disease and to develop countermeasures for the ongoing epidemic of Zika virus (ZIKV). Here we report that immunocompetent guinea pigs are susceptible to infection by a contemporary American strain of ZIKV. Dunkin-Hartley guinea pigs were inoculated with 10(6) plaque-forming units of ZIKV via subcutaneous route and clinical signs were observed. Viremia, viral load in the tissues, anti-ZIKV neutralizing antibody titer, and protein levels of multiple cytokine and chemokines were analyzed using qRT-PCR, plaque assay, plaque reduction neutralization test (PRNT) and multiplex immunoassay. Upon subcutaneous inoculation with PRVABC59 strain of ZIKV, guinea pigs demonstrated clinical signs of infection characterized by fever, lethargy, hunched back, ruffled fur, and decrease in mobility. ZIKV was detected in the whole blood and serum using qRT-PCR and plaque assay. Anti-ZIKV neutralizing antibody was detected in the infected animals using PRNT. ZIKV infection resulted in a dramatic increase in protein levels of multiple cytokines, chemokines and growth factors in the serum. ZIKV replication was observed in spleen and brain, with the highest viral load in the brain. This data demonstrate that after subcutaneous inoculation, the contemporary ZIKV strain is neurotropic in guinea pigs. The guinea pig model described here recapitulates various clinical features and viral kinetics observed in ZIKV-infected patients, and therefore may serve as a model to study ZIKV pathogenesis, including pregnancy outcomes and for evaluation of vaccines and therapeutics.

  4. Non-terminal blood sampling techniques in guinea pigs.

    PubMed

    Birck, Malene M; Tveden-Nyborg, Pernille; Lindblad, Maiken M; Lykkesfeldt, Jens

    2014-10-11

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical features of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.g., compared to mice and rats, are necessary to obtain sufficient and high quality samples. As both long and short term in vivo studies often require repeated blood sampling the choice of technique should be well considered in order to reduce stress and discomfort in the animals but also to ensure survival as well as compliance with requirements of sample size and accessibility. Venous blood samples can be obtained at a number of sites in guinea pigs e.g., the saphenous and jugular veins, each technique containing both advantages and disadvantages(4,5). Here, we present four different blood sampling techniques for either conscious or anaesthetized guinea pigs. The procedures are all non-terminal procedures provided that sample volumes and number of samples do not exceed guidelines for blood collection in laboratory animals(6). All the described methods have been thoroughly tested and applied for repeated in vivo blood sampling in studies within our research facility.

  5. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  6. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  7. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  8. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  9. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal...

  10. Induction and properties of guinea pig serum interferon. Preliminary report.

    PubMed

    Nolewajka, E; Mikolajski, K; Kapp-Burzyńska, Z; Trzeciak, J; Wrona, M

    1977-01-01

    Guinea pigs, 250-350 g body weight, both sexes, were injected with 5X10(8.5) EID50 NDV (Radom strain) intracardially and intraperitoneally simultaneously. The animals were bled by cardiac puncture 0, 3, 6, 12, 24 and 48 hours after injection. After virus inactivation, serum interferon titration was performed in cultures of guinea pig embryo kidney cells with 50 percent plaque inhibition test using VSV. The highest interferon titer (64 u./ml) was found after 6 hours of inductor injection. Interferon titer decreased quickly and after 12 hours it was lower than 16 u./ml. Guinea pig serum interferon induced by NDV was resistant to pH 2 and 56 degrees C during 1 hour. Interferon was inactivated by trypsin. The decribed interferon did not protect heterologous species cells (swine) against Teschen Disease Virus infection. Other properties of this interferon are being studied.

  11. Inhaled Bordetella pertussis vaccine decreases airway responsiveness in guinea pigs.

    PubMed

    Vargas, M H; Bazán-Perkins, B; Segura, P; Campos, M G; Selman, M; Montaño, L M

    1995-01-01

    Bordetella pertussis (BP) has been used as adjuvant for experimental animal immunization, but its effects on airway responsiveness are uncertain. Three groups of guinea pigs were used: animals with a single exposure to inhaled BP vaccine (strain 134, total dose 1.24 x 10(12) germs), animals submitted to a sensitization procedure through inhalation of ovalbumin plus BP, and healthy control animals. Four weeks after inhalation of BP or after the beginning of sensitization, dose- or concentration-response curves to histamine were constructed in vivo and in vitro (tracheal and parenchymal preparations). We found that BP alone produced lower responses to histamine than control guinea pigs in vivo (insufflation pressure, p = 0.0003) and in tracheal tissues (p = 0.04), but not in parenchymal preparations. Sensitization did not modify the responsiveness compared with their respective controls. These results suggest that some BP component(s), probably pertussis toxin, causes a long lasting airway hyporesponsiveness in guinea pigs.

  12. PSITTACOSIS : III. EXPERIMENTALLY INDUCED INFECTIONS IN RABBITS AND GUINEA PIGS.

    PubMed

    Rivers, T M; Berry, G P

    1931-06-30

    1. Rabbits and guinea pigs are susceptible to psittacosis virus introduced intracerebrally. By means of brain to brain passages in these animals the active agent is capable of propagation indefinitely. 2. Serial passages of the virus through rabbits and guinea pigs do not cause the active agent to lose its pathogenicity for parrots and mice. 3. The chief clinical evidences of infection in rabbits and guinea pigs following intracranial inoculation of the virus are fever and loss of weight. The pathological changes are characterized by a mild meningo-encephalitis, and fatty degeneration, focal necrosis, and infarction of the liver. 4. Rabbits upon recovery from an attack of psittacosis are actively immune. 5. Two strains of virus, human and parrot, were found to be immunologically similar. 6. No evidence was obtained to show that human convalescent serum possesses an appreciable amount of neutralizing substances.

  13. Guinea Pig Oxygen-Sensing and Carotid Body Functional Properties.

    PubMed

    Gonzalez-Obeso, Elvira; Docio, Inmaculada; Olea, Elena; Cogolludo, Angel; Obeso, Ana; Rocher, Asuncion; Gomez-Niño, Angela

    2017-01-01

    Mammals have developed different mechanisms to maintain oxygen supply to cells in response to hypoxia. One of those mechanisms, the carotid body (CB) chemoreceptors, is able to detect physiological hypoxia and generate homeostatic reflex responses, mainly ventilatory and cardiovascular. It has been reported that guinea pigs, originally from the Andes, have a reduced ventilatory response to hypoxia compared to other mammals, implying that CB are not completely functional, which has been related to genetically/epigenetically determined poor hypoxia-driven CB reflex. This study was performed to check the guinea pig CB response to hypoxia compared to the well-known rat hypoxic response. These experiments have explored ventilatory parameters breathing different gases mixtures, cardiovascular responses to acute hypoxia, in vitro CB response to hypoxia and other stimuli and isolated guinea pig chemoreceptor cells properties. Our findings show that guinea pigs are hypotensive and have lower arterial pO2 than rats, probably related to a low sympathetic tone and high hemoglobin affinity. Those characteristics could represent a higher tolerance to hypoxic environment than other rodents. We also find that although CB are hypo-functional not showing chronic hypoxia sensitization, a small percentage of isolated carotid body chemoreceptor cells contain tyrosine hydroxylase enzyme and voltage-dependent K(+) currents and therefore can be depolarized. However hypoxia does not modify intracellular Ca(2+) levels or catecholamine secretion. Guinea pigs are able to hyperventilate only in response to intense acute hypoxic stimulus, but hypercapnic response is similar to rats. Whether other brain areas are also activated by hypoxia in guinea pigs remains to be studied.

  14. Characteristic plethysmographic findings in a guinea pig model of COPD.

    PubMed

    Ramírez-Ramírez, Edgar; Torres-Ramírez, Armando; Alquicira-Mireles, Jesús; Cañavera-Constantino, Abraham; Segura-Medina, Patricia; Montaño-Ramírez, Martha; Ramos-Abraham, Carlos; Vargas, Mario H; Arreola-Ramírez, José Luis

    2017-03-01

    Long-term exposure to cigarette smoke generates chronic obstructive pulmonary disease (COPD) in guinea pigs, but a comprehensive evaluation of changes in lung function, as assessed by barometric whole body plethysmography (WBP), is lacking. Female guinea pigs were exposed to the smoke of 20 cigarettes/day, 5 days/week, during 10 weeks (COPD group, n = 8), and were compared with unexposed female guinea pigs of the same age (control group, n = 8). WBP was performed in both groups, followed by lung histology. At the end of the exposure period, guinea pigs in the COPD group had higher respiratory frequency, while duty cycle (Ti/Ttot) was unaffected. There was a trend toward minute ventilation (MV) and expiratory flow at the mid-tidal volume (EF50) to be higher in the COPD group. Enhanced pause (Penh) was lower, while time of braking (TB) and time to PEF relative to Te (Rpef) were higher in the COPD group. All guinea pigs exposed to tobacco smoke developed emphysematous lesions in their lungs and gained less body weight than controls. In this COPD model, exposure to cigarette smoke produced changes in WBP characterized by a shallow breathing pattern with decreased Penh and a trend toward increasing EF50 (probably due to decreased elastic recoil), increased TB (suggesting dynamic laryngeal narrowing), and a trend of increasing MV (probably due to a higher metabolic rate). Many of these functional changes resemble those observed in patients with COPD and corroborate the suitability of this guinea pig model for the study of COPD.

  15. Spontaneous cyclic embryonic movements in humans and guinea pigs.

    PubMed

    Felt, Renée H M; Mulder, Eduard J H; Lüchinger, Annemarie B; van Kan, Colette M; Taverne, Marcel A M; de Vries, Johanna I P

    2012-08-01

    Motility assessment before birth can be used to evaluate the integrity of the nervous system. Sideways bending (SB) of head and/or rump, the earliest embryonic motility in both humans and guinea pigs, can be visualized sonographically. We know from other species that early embryonic motility is cyclic. This study explores the distribution of SB-to-SB intervals in human and guinea pig embryos before the appearance of more complex movements such as general movements. We hypothesized that the activity in both species is cyclic. We made 15-min sonographic recordings of SBs between 5 weeks and 0 days (5wk0d) and 7wk0d conceptional age (CA) in 18 human embryos of uncomplicated IVF pregnancies (term 38 weeks) and in 20 guinea pig embryos between 3wk4d and 4wk0d CA (term 9 weeks). SB-to-SB interval durations were categorized as long (≥10 s) or short (<10 s) intervals. For human embryos, the median values for long and short intervals were 61 s (range, 10-165 s) and 3 s (range, 1-9 s) respectively; for guinea pigs 38 s (range, 10-288 s) and 5 s (range, 1-9 s), respectively. During development, the duration of long intervals decreased while the number of short intervals increased for both species. The earliest embryonic motility in the human and guinea pig is performed cyclically with distinct developmental milestones. The resemblance of their interval development offers promising possibilities to use the guinea pig as a noninvasive animal model of external influences on motor and neural development.

  16. Guinea Pig Oxygen-Sensing and Carotid Body Functional Properties

    PubMed Central

    Gonzalez-Obeso, Elvira; Docio, Inmaculada; Olea, Elena; Cogolludo, Angel; Obeso, Ana; Rocher, Asuncion; Gomez-Niño, Angela

    2017-01-01

    Mammals have developed different mechanisms to maintain oxygen supply to cells in response to hypoxia. One of those mechanisms, the carotid body (CB) chemoreceptors, is able to detect physiological hypoxia and generate homeostatic reflex responses, mainly ventilatory and cardiovascular. It has been reported that guinea pigs, originally from the Andes, have a reduced ventilatory response to hypoxia compared to other mammals, implying that CB are not completely functional, which has been related to genetically/epigenetically determined poor hypoxia-driven CB reflex. This study was performed to check the guinea pig CB response to hypoxia compared to the well-known rat hypoxic response. These experiments have explored ventilatory parameters breathing different gases mixtures, cardiovascular responses to acute hypoxia, in vitro CB response to hypoxia and other stimuli and isolated guinea pig chemoreceptor cells properties. Our findings show that guinea pigs are hypotensive and have lower arterial pO2 than rats, probably related to a low sympathetic tone and high hemoglobin affinity. Those characteristics could represent a higher tolerance to hypoxic environment than other rodents. We also find that although CB are hypo-functional not showing chronic hypoxia sensitization, a small percentage of isolated carotid body chemoreceptor cells contain tyrosine hydroxylase enzyme and voltage-dependent K+ currents and therefore can be depolarized. However hypoxia does not modify intracellular Ca2+ levels or catecholamine secretion. Guinea pigs are able to hyperventilate only in response to intense acute hypoxic stimulus, but hypercapnic response is similar to rats. Whether other brain areas are also activated by hypoxia in guinea pigs remains to be studied. PMID:28533756

  17. The Guinea Pig as a Model of Infectious Diseases

    PubMed Central

    Padilla-Carlin, Danielle J; McMurray, David N; Hickey, Anthony J

    2008-01-01

    The words ‘guinea pig’ are synonymous with scientific experimentation, but much less is known about this species than many other laboratory animals. This animal model has been used for approximately 200 y and was the first to be used in the study of infectious diseases such as tuberculosis and diphtheria. Today the guinea pig is used as a model for a number of infectious bacterial diseases, including pulmonary, sexually transmitted, ocular and aural, gastrointestinal, and other infections that threaten the lives of humans. Most studies on the immune response to these diseases, with potential therapies and vaccines, have been conducted in animal models (for example, mouse) that may have less similarity to humans because of the large number of immunologic reagents available for these other species. This review presents some of the diseases for which the guinea pig is regarded as the premier model to study infections because of its similarity to humans with regard to symptoms and immune response. Furthermore, for diseases in which guinea pigs share parallel pathogenesis of disease with humans, they are potentially the best animal model for designing treatments and vaccines. Future studies of immune regulation of these diseases, novel therapies, and preventative measures require the development of new immunologic reagents designed specifically for the guinea pig. PMID:18724774

  18. Isolated perfused liver model: the rat and guinea pig compared.

    PubMed

    Chaïb, Samira; Charrueau, Christine; Neveux, Nathalie; Coudray-Lucas, Colette; Cynober, Luc; De Bandt, Jean-Pascal

    2004-05-01

    Although the rat is the most commonly used species for the study of hepatic metabolism, the physiology of the guinea pig is closer to human physiology. We compared the model of isolated perfused guinea pig liver with the classic model of isolated perfused rat liver, especially with respect to amino acid metabolism. After validation of an anesthetic mixture of ketamine, diazepam, and xylazine for the guinea pig, isolated perfused livers were harvested for both species. Three groups of animals were compared for the study of liver metabolic fluxes: 6-wk-old male Sprague-Dawley rats (R; 230 +/- 10 g, n = 5), young male Hartley guinea pigs (YG; 223 +/- 8 g, n = 6) matched to rats by liver weight, and adult male Hartley guinea pigs (AG; 389 +/- 5 g, n = 6) matched to rats by age. Results (mean +/- standard error of the mean) were compared by analysis of variance and Newman-Keuls tests. Both models displayed a satisfactory hepatic viability, but differences were noted, with higher portal flows (R: 3.1 +/- 0.3 versus YG: 4.5 +/- 0.3 and AG: 4.2 +/- 0.3 mL. min(-1). g(-1); P < 0.05, YG and AG versus R) and bile flows (R: 0.34 +/- 0.01 versus YG: 2.38 +/- 0.22 versus AG: 3.17 +/- 0.28 microL. min(-1). g(-1); P < 0.05, YG and AG versus R, and YG versus AG) and higher amino acid fluxes (P < 0.05) leading to greater nitrogen uptake (P < 0.05) in guinea pigs. We performed a second set of experiments to evaluate the influence of anesthesia and portal flow on this last parameter. In these experiments, rats were anesthetized with ketamine, diazepam, and xylazine and guinea pig livers were perfused at rat blood flow. Apart from a 50% anesthesia-related mortality for rats, bile flow and metabolic parameters were only slightly modified. However, some amino acid fluxes were statistically different (aspartate, serine, and histidine; P < 0.05), as confirmed by a higher transfer constant. Our results indicate that the isolated perfused guinea pig liver is a suitable model for the study of

  19. DOCA-salts induce heart failure in the guinea pig.

    PubMed

    Tiritilli, A

    2001-10-01

    Heart failure (HF) is a common clinical problem confronting physicians and is often the final manifestation of many cardiovascular disorders. Despite recent advances in the pharmacological management of HF, it remains a highly lethal and disabling disorder. A number of animal models have been developed to study both the pathophysiology of HF and new therapeutic approaches to this complex syndrome. Only through an improved understanding of the basic biology of the early stages of the syndrome can HF be prevented or at least anticipated. With this in view, we have developed an easily realisable and inexpensive model in the guinea pig, which presents numerous structural, metabolic and biochemical similarities compared with the human heart. Thirty guinea pigs, aged 5 weeks and weighing 300 g were used. After anaesthesia, left nephrectomy was performed. After 1 week the guinea pigs were divided into: (a) control group (n=15), which received an injection of vehicle as well as tap water for 10 weeks; (b) DOCA-salts group (n=15), where the animals were treated with an IM injection of 10 mg DOCA 5 days a week for 10 weeks and with drinking water containing 9 g/l(-1) NaCl and 2 g/l(-1) KCl. Our results demonstrate that the administration of DOCA-salts to guinea pigs for 10 weeks caused a significant increase in blood pressure (BP+30%) associated with left ventricular hypertrophy (LVH), evaluated by LV weight (+37%), LV wall (+36%), by the ratio LV weight/Body weight (+23%) and by an increase in LV volume (+51%). Concerning HF, the latter was clinically evident through an increase in body weight, heart rate and dyspnoea. Indeed, guinea pigs presented pleural and/or pericardial effusion often associated with ascite. This model, which combines pressure and volume overload, results in a slow evolution towards HF. This allows a better understanding of the mechanisms in early LV remodelling which has the potential to develop into HF. Some recent studies have emphasised the value

  20. Vocal mother-offspring communication in guinea pigs: females adjust maternal responsiveness to litter size

    PubMed Central

    Kober, Melanie; Trillmich, Fritz; Naguib, Marc

    2008-01-01

    Background In parent-offspring communication, vocal signals are often used to attract attention and offspring might call to induce parental behaviour. In guinea pigs (Cavia aperea f. porcellus) mothers wean larger litters later than small ones, but it is unknown whether this difference depends on processes induced during pregnancy or is influenced post-natally by the number of pups present. We here tested with playback-experiments using pup separation calls whether mothers with cross-fostered large experimental litters (four-pup-litters) were more responsive to offspring calls and maintained responsiveness for longer than mothers with small experimental litters (two-pup-litters). Mothers were tested when two pups were suckling i.e. when both teats were occupied. Results Mothers of four-pup litters responded stronger to broadcast pup separation calls than those with two-pup litters. Additionally, we tested the mothers' responsiveness to pup separation calls in the absence of their pups on day 8 and 20 of lactation. Mothers of four-pup litters responded stronger and showed no decrease in responsiveness from day 8 to 20, whereas mothers of two-pup litters responded less and decreased responsiveness from day 8 to 20. Mothers of four-pup litters also weaned their pups 5 days later than those of two-pup litters. Conclusion Measured by their response to pup calls and by time to weaning, guinea pig mothers adjust maternal responsiveness to litter size. This behaviour is likely to be an adaptive strategy in resource allocation during reproduction. PMID:18783602

  1. Paternal intergenerational epigenetic response to heat exposure in male Wild guinea pigs.

    PubMed

    Weyrich, Alexandra; Lenz, Dorina; Jeschek, Marie; Chung, Tzu Hung; Rübensam, Kathrin; Göritz, Frank; Jewgenow, Katarina; Fickel, Jörns

    2016-04-01

    Epigenetic modifications, of which DNA methylation is the best studied one, can convey environmental information through generations via parental germ lines. Past studies have focused on the maternal transmission of epigenetic information to the offspring of isogenic mice and rats in response to external changes, whereas heterogeneous wild mammals as well as paternal epigenetic effects have been widely neglected. In most wild mammal species, males are the dispersing sex and have to cope with differing habitats and thermal changes. As temperature is a major environmental factor we investigated if genetically heterogeneous Wild guinea pig (Cavia aperea) males can adapt epigenetically to an increase in temperature and if that response will be transmitted to the next generation(s). Five adult male guinea pigs (F0) were exposed to an increased ambient temperature for 2 months, i.e. the duration of spermatogenesis. We studied the liver (as the main thermoregulatory organ) of F0 fathers and F1 sons, and testes of F1 sons for paternal transmission of epigenetic modifications across generation(s). Reduced representation bisulphite sequencing revealed shared differentially methylated regions in annotated areas between F0 livers before and after heat treatment, and their sons' livers and testes, which indicated a general response with ecological relevance. Thus, paternal exposure to a temporally limited increased ambient temperature led to an 'immediate' and 'heritable' epigenetic response that may even be transmitted to the F2 generation. In the context of globally rising temperatures epigenetic mechanisms may become increasingly relevant for the survival of species. © 2015 John Wiley & Sons Ltd.

  2. [Effects of Yanggan Lidan Granule on insulin resistance in guinea pigs with induced cholesterol gallstones].

    PubMed

    Fang, Bang-jiang; Zhou, Shuang; Pei, Xin-jun; Huang, Jin-yang; Chen, Bao-jin; Geng, Yun; Yang, Li-kun

    2009-12-01

    To observe the effects of Yanggan Lidan Granule (YGLDG), a compound traditional Chinese herbal medicine, on insulin resistance in guinea pigs with induced cholesterol gallstones. Eighty guinea pigs were randomly divided into normal control group, untreated group, YGLDG group and ursodeoxycholic acid (UDCA) group, with 20 guinea pigs in each group. Except the normal control group, gallstones were induced by high-cholesterol diet in the guinea pigs. The guinea pigs in the normal control group and the untreated group were administered with normal saline. UDCA and YGLDG were given to the guinea pigs in the corresponding groups for seven weeks. Eight guinea pigs of each group were used to measure the glucose infusion rate (GIR) by using hyperinsulinemic-euglycemic clamp technique. At the end the guinea pigs were killed and their gallstone formation was observed. The gallstones in guinea pigs were identified as cholesterol stones by qualitative analysis through infrared spectrum. The incidence rate of cholelithiasis of the untreated group was 82.35% . The GIR of guinea pigs in the untreated group was obviously lowered down as compared with the normal control group. Compared with the untreated group, the GIRs of the YGLDG group and the UDCA group were obviously increased, especially in the YGLDG group. YGLDG may improve insulin resistance in guinea pigs with cholesterol gallstones by elevating GIR obviously.

  3. Cartilage Degeneration, Subchondral Mineral and Meniscal Mineral Densities in Hartley and Strain 13 Guinea Pigs.

    PubMed

    Sun, Yubo; Scannell, Brian P; Honeycutt, Patrick R; Mauerhan, David R; H, James Norton; Hanley, Edward N

    2015-01-01

    Osteoarthritis is a joint disease involved in articular cartilage, subchondral bone, meniscus and synovial membrane. This study sought to examine cartilage degeneration, subchondral bone mineral density (BMD) and meniscal mineral density (MD) in male Hartley, female Hartley and female strain 13 guinea pigs to determine the association of cartilage degeneration with subchondral BMD and meniscal MD. Cartilage degeneration, subchondral BMD and meniscal MD in 12 months old guinea pigs were examined with histochemistry, X-ray densitometry and calcium analysis. We found that male Hartley guinea pigs had more severe cartilage degeneration, subchondral BMD and meniscal MD than female Hartley guinea pigs, but not female strain 13 guinea pigs. Female strain 13 guinea pigs had more severe cartilage degeneration and higher subchondral BMD, but not meniscal MD, than female Hartley guinea pigs. These findings indicate that higher subchondral BMD, not meniscal MD, is associated with more severe cartilage degeneration in the guinea pigs and suggest that abnormal subchondral BMD may be a therapeutic target for OA treatment. These findings also indicate that the pathogenesis of OA in the male guinea pigs and female guinea pigs are different. Female strain 13 guinea pig may be used to study female gender-specific pathogenesis of OA.

  4. Cartilage Degeneration, Subchondral Mineral and Meniscal Mineral Densities in Hartley and Strain 13 Guinea Pigs

    PubMed Central

    Sun, Yubo; Scannell, Brian P; Honeycutt, Patrick R; Mauerhan, David R; H, James Norton; Hanley Jr, Edward N

    2015-01-01

    Osteoarthritis is a joint disease involved in articular cartilage, subchondral bone, meniscus and synovial membrane. This study sought to examine cartilage degeneration, subchondral bone mineral density (BMD) and meniscal mineral density (MD) in male Hartley, female Hartley and female strain 13 guinea pigs to determine the association of cartilage degeneration with subchondral BMD and meniscal MD. Cartilage degeneration, subchondral BMD and meniscal MD in 12 months old guinea pigs were examined with histochemistry, X-ray densitometry and calcium analysis. We found that male Hartley guinea pigs had more severe cartilage degeneration, subchondral BMD and meniscal MD than female Hartley guinea pigs, but not female strain 13 guinea pigs. Female strain 13 guinea pigs had more severe cartilage degeneration and higher subchondral BMD, but not meniscal MD, than female Hartley guinea pigs. These findings indicate that higher subchondral BMD, not meniscal MD, is associated with more severe cartilage degeneration in the guinea pigs and suggest that abnormal subchondral BMD may be a therapeutic target for OA treatment. These findings also indicate that the pathogenesis of OA in the male guinea pigs and female guinea pigs are different. Female strain 13 guinea pig may be used to study female gender-specific pathogenesis of OA. PMID:26401159

  5. Development of a Guinea Pig Lung Deposition Model

    DTIC Science & Technology

    2016-01-01

    6 3.4. MECHANISTIC MODEL OF PARTICLE DEPOSITION IN THE LUNG ................................. 7 4.0 SOFTWARE IMPLEMENTATION...4 Figure 2. Particle deposition in the lung of the guinea pig via endotracheal breathing...10 Figure 3. Deposition fraction of various size particles at different lung depths. ..................................... 11 Figure 4

  6. Plague in Guinea pigs and its prevention by subunit vaccines.

    PubMed

    Quenee, Lauriane E; Ciletti, Nancy; Berube, Bryan; Krausz, Thomas; Elli, Derek; Hermanas, Timothy; Schneewind, Olaf

    2011-04-01

    Human pneumonic plague is a devastating and transmissible disease for which a Food and Drug Administration-approved vaccine is not available. Suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. To develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. On intranasal instillation of a fully virulent strain, Yersinia pestis CO92, guinea pigs developed lethal lung infections with hemorrhagic necrosis, massive bacterial replication in the respiratory system, and blood-borne dissemination to other organ systems. Expression of the Y. pestis F1 capsule was not required for the development of pulmonary infection; however, the capsule seemed to be important for the establishment of bubonic plague. The mean lethal dose (MLD) for pneumonic plague in guinea pigs was estimated to be 1000 colony-forming units. Immunization of guinea pigs with the recombinant forms of LcrV, a protein that resides at the tip of Yersinia type III secretion needles, or F1 capsule generated robust humoral immune responses. Whereas LcrV immunization resulted in partial protection against pneumonic plague challenge with 250 MLD Y. pestis CO92, immunization with recombinant F1 did not. rV10, a vaccine variant lacking LcrV residues 271-300, elicited protection against pneumonic plague, which seemed to be based on conformational antibodies directed against LcrV. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  7. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    NASA Technical Reports Server (NTRS)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  8. Plague in Guinea Pigs and Its Prevention by Subunit Vaccines

    PubMed Central

    Quenee, Lauriane E.; Ciletti, Nancy; Berube, Bryan; Krausz, Thomas; Elli, Derek; Hermanas, Timothy; Schneewind, Olaf

    2011-01-01

    Human pneumonic plague is a devastating and transmissible disease for which a Food and Drug Administration–approved vaccine is not available. Suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. To develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. On intranasal instillation of a fully virulent strain, Yersinia pestis CO92, guinea pigs developed lethal lung infections with hemorrhagic necrosis, massive bacterial replication in the respiratory system, and blood-borne dissemination to other organ systems. Expression of the Y. pestis F1 capsule was not required for the development of pulmonary infection; however, the capsule seemed to be important for the establishment of bubonic plague. The mean lethal dose (MLD) for pneumonic plague in guinea pigs was estimated to be 1000 colony-forming units. Immunization of guinea pigs with the recombinant forms of LcrV, a protein that resides at the tip of Yersinia type III secretion needles, or F1 capsule generated robust humoral immune responses. Whereas LcrV immunization resulted in partial protection against pneumonic plague challenge with 250 MLD Y. pestis CO92, immunization with recombinant F1 did not. rV10, a vaccine variant lacking LcrV residues 271-300, elicited protection against pneumonic plague, which seemed to be based on conformational antibodies directed against LcrV. PMID:21406168

  9. EFFECTS OF METHYLNALTREXONE ON GUINEA PIG GASTROINTESTINAL MOTILITY

    PubMed Central

    Anselmi, Laura; Huynh, Jennifer; Vegezzi, Gaia; Sternini, Catia

    2013-01-01

    The purpose of the present study was to compare the effects of methylnaltrexone (MNTX), a peripherally acting μ opioid receptor (μOR) antagonist, on gastrointestinal (GI) motility in naïve vs. opiate-chronically treated guinea pigs in vitro and in vivo. We have used the electrically stimulated muscle twitch contractions of longitudinal muscle-myenteric plexus (LMMP) preparations and total GI transit as measure of GI motility. In LMMP preparations of naïve guinea pigs, MNTX (1–30 μM) induced a significant, dose-response reduction of morphine-induced inhibition of electrically stimulated muscle twitch contractions, with an IC50 of 9.4 10−8M. By contrast, MNTX abolished the inhibitory effect of acute morphine at any concentration tested (1–30 μM) in the guinea pigs chronically treated with opiates. In vivo, MNTX (10–50 mg s.c.) did not affect GI transit in naïve guinea pigs when administered acutely or for 5 consecutive days, but reversed the GI transit delay induced by chronic morphine treatment. These findings show that MNTX is effective in reversing opiate-induced inhibition of GI motility acting at peripheral μORs, but does not exert a pharmacologic effect on GI transit in the absence of opiate stimulation. PMID:23361094

  10. Ototoxic drugs: difference in sensitivity between mice and guinea pigs.

    PubMed

    Poirrier, A L; Van den Ackerveken, P; Kim, T S; Vandenbosch, R; Nguyen, L; Lefebvre, P P; Malgrange, B

    2010-03-01

    The development of experimental animal models has played an invaluable role in understanding the mechanisms of neurosensory deafness and in devising effective treatments. The purpose of this study was to develop an adult mouse model of ototoxic drug-induced hearing loss and to compare the ototoxicity in the adult mouse to that in the well-described guinea pig model. Mice are a powerful model organism, especially due to the large availability of antibodies, probes and genetic mutants. In this study, mice (n=114) and guinea pigs (n=35) underwent systemic treatment with either kanamycin or cisplatin. Auditory brainstem responses showed a significant threshold shift in guinea pigs 2 weeks after the beginning of the ototoxic treatment, while there was no significant hearing impairment recorded in mice. Hair cells and neuronal loss were correlated with hearing function in both guinea pigs and mice. These results indicate that the mouse is not a good model for ototoxicity, which should be taken into consideration in all further investigations concerning ototoxicity-induced hearing loss.

  11. Improved Method for Culturing Guinea-Pig Macrophage Cells

    NASA Technical Reports Server (NTRS)

    Savage, J.

    1982-01-01

    Proper nutrients and periodic changes in culture medium maintain cell viability for a longer period. New method uses a thioglycolate solution, instead of mineral oil, to induce macrophage cells in guinea pigs and also uses an increased percent of fetal-calf bovine serum in cultivation medium. Macrophage cells play significant roles in the body's healing and defense systems.

  12. Calcium influx and postjunctional supersensitivity in guinea pig aortic strips.

    PubMed

    Kaiman, M; Shibata, S

    1976-05-01

    Both reserpine and 6-hydroxydopamine (6-OHDA) pretreatment potentiated the sensitivity of guinea pig aortic strips to norepinephrine (NE), barium, methoxamine and potassium indicating postjunctional supersensitivity. However, cocaine treatmetn only potentiated the NE response indicating prejunctional supersensitivity. 6-OHDA and reserpine-induced supersensitivity but not cocaine-induced supersensitivity was accompanied by an increase in 45Ca influx.

  13. Reflections on the Fiftieth Reunion of the Guinea Pigs.

    ERIC Educational Resources Information Center

    Loud, Oliver

    1988-01-01

    A member of the original faculty of the experimental Ohio State University Laboratory High School reflects at a fiftieth reunion of the first graduating class. Students were used as guinea pigs to determine the effects of providing teenagers with liberating, interesting, and customized education from university faculty. (SM)

  14. Reflections on the Fiftieth Reunion of the Guinea Pigs.

    ERIC Educational Resources Information Center

    Loud, Oliver

    1988-01-01

    A member of the original faculty of the experimental Ohio State University Laboratory High School reflects at a fiftieth reunion of the first graduating class. Students were used as guinea pigs to determine the effects of providing teenagers with liberating, interesting, and customized education from university faculty. (SM)

  15. Improved Method for Culturing Guinea-Pig Macrophage Cells

    NASA Technical Reports Server (NTRS)

    Savage, J.

    1982-01-01

    Proper nutrients and periodic changes in culture medium maintain cell viability for a longer period. New method uses a thioglycolate solution, instead of mineral oil, to induce macrophage cells in guinea pigs and also uses an increased percent of fetal-calf bovine serum in cultivation medium. Macrophage cells play significant roles in the body's healing and defense systems.

  16. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    NASA Technical Reports Server (NTRS)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  17. Purinergic regulation of guinea pig suburothelial myofibroblasts

    PubMed Central

    Wu, C; Sui, G P; Fry, C H

    2004-01-01

    The Ca2+-regulating and electrophysiological properties of guinea-pig suburothelial myofibroblasts have been measured in order to investigate their potential role in the sensation of bladder fullness, due to their strategic position between the urothelium and afferent fibres. Previous work has shown that stretch of the bladder wall releases ATP. Cells that stain positively for vimentin were isolated. About 45% of cells (median membrane capacitance 13.3 pF) exhibited spontaneous depolarizations to about −25 mV with a physiological Cl− gradient (frequency 2.6 ± 1.5 min−1, duration 14.5 ± 2.2 s, n = 15). Under voltage-clamp spontaneous inward currents (frequency 1.5 ± 0.2 min−1, duration 14.5 ± 7.0 s, n = 18) were recorded, with a similar reversal potential. The spontaneous currents were preceded by intracellular Ca2+ transients with a magnitude that was independent of membrane potential. All cells tested responded to ATP by generating an intracellular Ca2+ transient, followed by inward currents; the currents had a similar reversal potential and slope conductance to their spontaneous counterparts. ATP-generated transients were mimicked by UTP and ADP but not by α,β-methylene-ATP (1–10 μm) or CTP (30 μm), indicating that ATP acts via a P2Y receptor. Transients were partially attenuated by 1 mm suramin but PPADS (80 μm) had no effect. These data indicate that ATP acts via a P2Y receptor, but responses were resistant to the P2Y1 antagonist MRS2179. ATP-generated transients were abolished by intracellular perfusion with heparin and TMB-8 indicating that IP3 was the intracellular second messenger. The reversal potentials of the spontaneous and ATP-generated currents were shifted by about +45 mV by a 12-fold reduction of the extracellular [Cl−] and the currents were greatly attenuated by 1 mm DIDS. No transients were generated on exposure to the muscarinic agonist carbachol. We propose that these cells may play a regulatory step in the sensation of

  18. Guinea pig alpha 1-microglobulin/bikunin: cDNA sequencing, tissue expression and expression during acute phase.

    PubMed

    Yoshida, K; Suzuki, Y; Yamamoto, K; Sinohara, H

    1999-02-01

    cDNA encoding alpha 1-microglobulin/bikunin (AMBP) was amplified from guinea pig (Cavia porcellus) liver mRNA by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends methods, cloned and sequenced. The deduced amino acid sequence was found to be homologous to the sequence of AMBP of other mammals (69-76% amino acid identity). It has two Kunitz-type trypsin inhibitor domains in the bikunin part as reactive sites, one in the N-terminal region and another in the C-terminal region. The N-terminal inhibitor domain sequence is well-conserved, but the P1 residue of the C-terminal inhibitor domain sequence was found to be Gln rather than Arg, a residue highly conserved in the AMBP of seven other mammals examined to date. By RT-PCR and nested PCR, AMBP mRNA was detected not only in liver tissue, previously known to be a site of its synthesis, but also in pancreas, stomach, small intestine, colon, lung, spleen, kidney, testis, skeletal muscle, and leukocytes, but not in brain or heart. We examined the AMBP mRNA levels in guinea pig liver by RT-PCR, comparing normal levels and those in a state of inflammation. The mRNA levels, however, did not significantly change.

  19. Quantitative study on guinea pig spermatogenesis shows a relative high percentage of early meiotic prophase stages.

    PubMed

    Rodríguez, Rosana E; Wettstein, Rodolfo M

    2004-05-01

    Meiosis is the special double cellular division characterized by the reduction of chromosome number of the final products and recombination of genetic information present in maternal and paternal homologous chromosomes. Early stages of meiotic prophase, leptotene and zygotene (L/Z), are functionally important since homologous chromosomes recognize, align, and pair during them. They are poorly represented in the seminiferous tubules of mammalian species, and this fact turns studies focused on these stages difficult to perform. As a consequence, the molecular bases of these important events are so far poorly known and understood in higher eukaryotes. The purpose of this work was to provide an advantageous experimental mammalian model (with a reasonable number of cells) for biochemical and molecular analysis of early meiotic prophase stages. Here, we present the results of our quantitative study on testes material of both immature and adult guinea pig specimens (Cavia porcellus). We show that their seminiferous tubules contain a comparatively high percentage of L/Z spermatocytes, as well as a very conspicuous chromosome bouquet at the L/Z transition, which points out this species as a well-suited one to address studies on such stages in mammals.

  20. Hematological profile of the euthymic hairless guinea pig following sulfur mustard vesicant exposure.

    PubMed

    Gold, M B; Scharf, B A

    1995-01-01

    Sulfur mustard (HD) is a potent vesicating agent of military importance, with known radiomimetic properties. The euthymic hairless guinea pig (EHGP) (Cavia porcellus) is emerging as the animal model of choice for cutaneous HD study. With elucidation of the systemic effects, we may better utilize this animal for all HD toxicity work. To this end, studies were conducted to determine the definitive median lethal dose (MLD) of subcutaneously applied sulfur mustard (HD) in the EHGP, and to correlate the induced hematological changes. Eight groups of two animals each were dosed at 0.3 log intervals from an extrapolated expected dose, deriving a tentative mean around which five groups of six animals each were dosed at 0.1 log intervals, resulting in a definitive MLD of 48.17 mg kg(-1). Sulfur mustard was then administered to seven groups of six animals each at a dose of 30 mg kg(-1) and hematology performed. Significant leukocyte count suppression was found to occur on days 4, 5 and 6, following a leukocyte elevation on day 1 after exposure. Serum potassium levels were found to be elevated all 7 days after HD exposure. Establishing the MLD for subcutaneously applied HD and the pattern of induced leukocyte suppression allows for more definitive evaluation of successful toxicity counter-measures.

  1. The Guinea Pig as a Model for Sporadic Alzheimer’s Disease (AD): The Impact of Cholesterol Intake on Expression of AD-Related Genes

    PubMed Central

    Ong, Daniel; Wijaya, Linda; Laws, Simon M.; Taddei, Kevin; Newman, Morgan; Lardelli, Michael; Martins, Ralph N.; Verdile, Giuseppe

    2013-01-01

    We investigated the guinea pig, Cavia porcellus, as a model for Alzheimer’s disease (AD), both in terms of the conservation of genes involved in AD and the regulatory responses of these to a known AD risk factor - high cholesterol intake. Unlike rats and mice, guinea pigs possess an Aβ peptide sequence identical to human Aβ. Consistent with the commonality between cardiovascular and AD risk factors in humans, we saw that a high cholesterol diet leads to up-regulation of BACE1 (β-secretase) transcription and down-regulation of ADAM10 (α-secretase) transcription which should increase release of Aβ from APP. Significantly, guinea pigs possess isoforms of AD-related genes found in humans but not present in mice or rats. For example, we discovered that the truncated PS2V isoform of human PSEN2, that is found at raised levels in AD brains and that increases γ-secretase activity and Aβ synthesis, is not uniquely human or aberrant as previously believed. We show that PS2V formation is up-regulated by hypoxia and a high-cholesterol diet while, consistent with observations in humans, Aβ concentrations are raised in some brain regions but not others. Also like humans, but unlike mice, the guinea pig gene encoding tau, MAPT, encodes isoforms with both three and four microtubule binding domains, and cholesterol alters the ratio of these isoforms. We conclude that AD-related genes are highly conserved and more similar to human than the rat or mouse. Guinea pigs represent a superior rodent model for analysis of the impact of dietary factors such as cholesterol on the regulation of AD-related genes. PMID:23805206

  2. Antibodies to spermatozoa. III. Responses in rabbits and guinea-pigs to immunization with guinea-pig sperm cells

    PubMed Central

    Hekman, Annemarie; Shulman, S.

    1971-01-01

    The antigens of guinea-pig sperm cells, of both the epididymal and ejaculated (or seminal) types, have been studied, using rabbit and guinea-pig antisera. Several antigens could be revealed by gel diffusion studies, using well-washed but non-ruptured sperm cells, indicating that intentional cell breaking is not essential for demonstrating the antigens. This release of soluble antigen was followed as a function of time and temperature, both as total protein in supernatants and in increasing strength of precipitation. With rabbit antiserum, epididymal sperm showed two antigens, that were also demonstrated in epididymal and testicular extract and in seminal sperm. These other materials revealed additional antigens with these antisera. Immunofluorescent staining was limited to the acrosomes. With guinea-pig antibodies, no precipitating antigen that was characteristic of sperm could be seen. These antisera showed immunofluorescent staining of the acrosomes. The staining could be distinguished, in terms of thermostability, from the staining produced by normal serum. No evidence was found for the occurrence of any sperm-coating antigens in the guinea-pig, especially since both antiseminal plasma and antivesicular fluid antisera failed to give immunofluorescent staining of the sperm cells. ImagesFig. 1Fig. 3Fig. 4Fig. 5Fig. 6 PMID:4998924

  3. High-purity flow sorting of early meiocytes based on DNA analysis of guinea pig spermatogenic cells.

    PubMed

    Rodríguez-Casuriaga, Rosana; Geisinger, Adriana; Santiñaque, Federico F; López-Carro, Beatriz; Folle, Gustavo A

    2011-08-01

    Mammalian spermatogenesis is still nowadays poorly understood at the molecular level. Testis cellular heterogeneity is a major drawback for spermatogenic gene expression studies, especially when research is focused on stages that are usually very short and poorly represented at the cellular level such as initial meiotic prophase I (i.e., leptotene [L] and zygotene [Z]). Presumably, genes whose products are involved in critical meiotic events such as alignment, pairing and recombination of homologous chromosomes are expressed during the short stages of early meiotic prophase. Aiming to characterize mammalian early meiotic gene expression, we have found the guinea pig (Cavia porcellus) as an especially attractive model. A detailed analysis of its first spermatogenic wave by flow cytometry (FCM) and optical microscopy showed that guinea pig testes exhibit a higher representation of early meiotic stages compared to other studied rodents, partly because of their longer span, and also as a result of the increased number of cells entering meiosis. Moreover, we have found that adult guinea pig testes exhibit a peculiar 4C DNA content profile, with a bimodal peak for L/Z and P spermatocytes that is absent in other rodents. Besides, we show that this unusual 4C peak allows the separation by FCM of highly pure L/Z spermatocyte populations aside from pachytene ones, even from adult individuals. To our knowledge, this is the first report on an accurate and suitable method for highly pure early meiotic prophase cell isolation from adult mammals, and thus sets an interesting approach for gene expression studies aiming at a deeper understanding of the molecular groundwork underlying male gamete production.

  4. Effect of Hypergravity Stress on Gaseous Exchange and Survival of Young and Old Guinea Pigs

    NASA Astrophysics Data System (ADS)

    Muradian, Kh. K.; Timchenko, A. N.

    Hypergravity tolerance decreases in aging Guinea pigs, the range being lower than in other studied species of laboratory mammals - mice, hamsters, and rats. Moreover, for the gaseous exchange rate and body temperature, the decline during the stress is not characteristic for Guinea pigs of both age groups, in contrast to other species. In general, hypergravity tolerance of Guinea pigs could be more appropriate experimental models.

  5. [Use of guinea pigs for assessing the efficacy of vaccines against Lassa fever].

    PubMed

    Firsova, I V; Shatokhina, I V; Borisevich, I V; Evseev, A A; Maksimov, V A; Pantiukhov, V B; Khmelev, A L

    2003-01-01

    The use of guinea pigs as a laboratory model was proven to be appropriate in investigating the vaccines developed against Lassa fever at the preclinical study stage. An adapted variant of Lassa virus was cultivated, which caused death of guinea pigs with respect for an agent's dose. Finally, it was shown to be possible to investigate the immunogenic and protective properties of the inactivated antigen of Lassa virus in experiments with guinea pigs.

  6. Injuries caused by pigs in Papua New Guinea.

    PubMed

    Barss, P; Ennis, S

    Pigs are intelligent animals that can be formidable adversaries to humans because of their sharp tusks and their ability to attack swiftly. Domestic and feral pigs have an important role in the ecology of village life in Melanesia. A six-year review of all injuries that were caused by pigs that were referred from the villages in Milne Bay Province, Papua New Guinea, to the Provincial Hospital was completed. Some of the injuries that were seen among the 20 patients who were studied included: three penetrating abdominal injuries with prolapse and strangulation of the intestine; a "sucking" chest wound; bilateral pneumothoraces; two infected open fractures of the radius and the ulna; a perforating injury of the knee with septic arthritis; a hand injury with laceration of multiple tendons; an arterial injury of the wrist; injury of a tibial nerve with foot drop; and a severe scrotal injury with exposure of the testicles. Most injuries resulted from the hunting of feral pigs. Adult male hunters who used dogs and carried only one spear were injured most frequently. Wounds from injuries by pigs are deep, often involve multiple critical structures, and are grossly contaminated. Resuscitation requires the administration of fluid and often blood. Treatment includes irrigation, debridement and closure of the wound. The principles of managing such injuries, the prevention of injuries, the ecology of pigs and humans, human infections originating from pigs, and safer methods of hunting pigs are discussed.

  7. Mammary gland tumors in irradiated and untreated guinea pigs

    SciTech Connect

    Hoch-Ligeti, C.; Liebelt, A.G.; Congdon, C.C.; Stewart, H.L.

    1986-01-01

    This is a report of mammary gland tumors from 62 guinea pigs. The tumors arose in the terminal ductal-lobular units as either lobular acinar carcinoma or cystadenocarcinoma or as papillary carcinomas within large ducts near the mammilla. About half the number of the males had terminal ductal-lobular carcinomas and all but 2 of the papillary duct carcinomas also arose in males. Large tumors frequently exhibited squamous, chondromatous, osseous, fatty and myoepitheliomatous types of tissues. In 2 irradiated males and 1 female the tumors metastasized. Whole-body irradiation did not produce significant changes in the number or sex distribution or in the morphology of mammary gland tumors in inbred or outbred guinea pigs. All females had cystic ovaries without increase in granulosa cells, 24 (66.6%) had uterine tumors and 13 (34.2%) had adrenal gland tumors; all males had atrophic testes, 5 (16.5%) had testicular and 6 (22.2%) had adrenal gland tumors.

  8. Mandibular condylectomy in the guinea pig: quantitative triple fluorochrome study.

    PubMed

    Soni, N N; Malloy, R B

    1976-01-01

    Different-colored fluorochromes were administered sequentially to guinea pigs and the rate of bone formation measured in their condylectomized control contralateral hemimandibles. The values for labeled bone for condylectomized hemimandibles were lower than for the control contralateral hemimandibles of the same guinea pig. The differences in values of condylectomized and control contralateral sides for DCTC- and total surface area-labeled bone were statistically significant, but were not statistically significant for DCAF- and hematoporphyrin-labeled bone. There was partial regeneration of the condylar process. Although the condylectomized area was nearly normal in shape, its size and proportions were different from those of the contralateral hemimandibles that were not operated on. The greatest differences were noted in the length, height, and the distances measured between the inferior alveolar foramen and the mental foramen and the posterior border of the condyle.

  9. Spontaneous Ameloblastic Fibroma in a Young Guinea Pig

    PubMed Central

    Tanaka, Makoto; Sawamoto, Osamu

    2013-01-01

    A spontaneous ameloblastic fibroma was found in a 9-week-old guinea pig. Histopathologically, neoplastic cells consisted of two components: an odontogenic epithelium and odontogenic mesenchyme. The odontogenic epithelium formed strands, nests and islands that were interspersed within the odontogenic mesenchyme. In the marginal region, odontoblasts and scant dysplastic eosinophilic material were seen between these two components. Immunohistochemically, the odontogenic epithelium was positive for cytokeratin AE1/AE3, and the odontogenic mesenchyme and odontoblast were positive for vimentin, in the same manner as in the normal tooth germ (control). We could not obtain conclusive data suggesting that the eosinophilic material was dental hard tissue because the eosinophilic material was not stained specifically by any methods. Based on these histological characteristics, the tumor in the present case was diagnosed as an ameloblastic fibroma. This is the first report of ameloblastic fibroma in guinea pigs. PMID:24155567

  10. Spontaneous ameloblastic fibroma in a young Guinea pig.

    PubMed

    Tanaka, Makoto; Sawamoto, Osamu

    2013-09-01

    A spontaneous ameloblastic fibroma was found in a 9-week-old guinea pig. Histopathologically, neoplastic cells consisted of two components: an odontogenic epithelium and odontogenic mesenchyme. The odontogenic epithelium formed strands, nests and islands that were interspersed within the odontogenic mesenchyme. In the marginal region, odontoblasts and scant dysplastic eosinophilic material were seen between these two components. Immunohistochemically, the odontogenic epithelium was positive for cytokeratin AE1/AE3, and the odontogenic mesenchyme and odontoblast were positive for vimentin, in the same manner as in the normal tooth germ (control). We could not obtain conclusive data suggesting that the eosinophilic material was dental hard tissue because the eosinophilic material was not stained specifically by any methods. Based on these histological characteristics, the tumor in the present case was diagnosed as an ameloblastic fibroma. This is the first report of ameloblastic fibroma in guinea pigs.

  11. Role of leukotrienes in airway hyperresponsiveness in guinea-pigs.

    PubMed Central

    Ishida, K.; Thomson, R. J.; Schellenberg, R. R.

    1993-01-01

    1. Repeated aerosolization of leukotriene C4 (LTC4) to guinea-pigs produced leftward shift in their pulmonary resistance (RL) dose-response curves to inhaled acetylcholine (ACh) without increasing the maximum responses. 2. Repeated LTC4 aerosolization did not increase airway eosinophils. 3. The 5-lipoxygenase-activating protein (FLAP) inhibitor, MK-886, prevented the leftward shift in RL dose-response curves to ACh following repeated antigen challenge in guinea-pigs. 4. MK-886 did not inhibit the increased maximal RL produced by repeated antigen challenge, nor inhibit the airway eosinophilia induced by repeated antigen challenge. 5. Our findings suggest that leukotrienes may account for the leftward shift in pulmonary resistance responses caused by antigen but do not cause the airway eosinophilia nor enhanced maximum broncho-constrictor response to antigen. PMID:8467358

  12. Interstitial pneumonitis induced in guinea pigs by Triatoma infestans antigens.

    PubMed

    Alonso, A; Caccuri, R L; Scavini, L M; Rodríguez, S M; Marino, G A

    1994-01-01

    Data concerning the experimental induction of hypersensitivity pneumonitis in guinea pigs with a Triatoma infestans antigen are presented. Glycoproteins obtained from the chitinous structures of T. infestans (79 kd + 11 kd) were aerosolized daily to guinea pigs during 7 weeks. The presence of specific antibodies (IgG and IgE) was detected by serological techniques; histopathological studies of the lungs showed interstitial infiltrates of macrophages and T-cells. Single non-necrotizing granulomas were seen at the seventh week of the experiment. The results from this animal model suggest that this hypersensitivity pneumonitis is a typical delayed-type reaction due to chronic contact with the heterologous glycoproteins of T. infestans.

  13. RELEASE OF KALLIKREIN FROM GUINEA PIG LUNG DURING ANAPHYLAXIS

    PubMed Central

    Jonasson, O.; Becker, E. L.

    1966-01-01

    An antigen-antibody reaction occurring in the perfused sensitized guinea pig lung, has been demonstrated to release kallikrein, a proteolytic enzyme related to the formation of kinins. This lung kallikrein is similar to plasma kallikrein in all properties studied, including susceptibility to the same inhibitors, electrophoretic mobility, and heterogeneity in molecular size. The release of kallikrein during anaphylaxis in the guinea pig lung occurs in the presence of ethylenediaminetetraacetate. Perfusion of ellagic acid into nonsensitized lungs will also release kallikrein, presumably through activation of Hageman factor. On the basis of these findings the hypothesis is suggested that the kallikrein in perfused lung activated by the antigen-antibody reaction is, in fact, plasma kallikrein. It is further suggested that activation of such kallikrein by the antigen-antibody reaction proceeds through Hageman factor. PMID:5937059

  14. Preliminary pharmacokinetic study of repeated doses of rifampin and rifapentine in guinea pigs.

    PubMed

    Dutta, Noton K; Alsultan, Abdullah; Peloquin, Charles A; Karakousis, Petros C

    2013-03-01

    Substitution of rifapentine (RFP) for rifampin (RIF) in the standard antituberculous regimen reduces the time required to cure chronic tuberculosis (TB) infection in mice, but not in guinea pigs. In order to gain insight into these discrepant findings, we conducted a steady-state pharmacokinetic (PK) study in healthy guinea pigs to study the metabolism and autoinduction of RIF and RFP. Both RFP and RIF 25-desacetyl metabolites (desRFP and desRIF, respectively), were detected at low concentrations in the serum of guinea pigs. The metabolite concentrations in guinea pigs are much lower than those seen in humans at steady state.

  15. Preliminary Pharmacokinetic Study of Repeated Doses of Rifampin and Rifapentine in Guinea Pigs

    PubMed Central

    Dutta, Noton K.; Alsultan, Abdullah; Peloquin, Charles A.

    2013-01-01

    Substitution of rifapentine (RFP) for rifampin (RIF) in the standard antituberculous regimen reduces the time required to cure chronic tuberculosis (TB) infection in mice, but not in guinea pigs. In order to gain insight into these discrepant findings, we conducted a steady-state pharmacokinetic (PK) study in healthy guinea pigs to study the metabolism and autoinduction of RIF and RFP. Both RFP and RIF 25-desacetyl metabolites (desRFP and desRIF, respectively), were detected at low concentrations in the serum of guinea pigs. The metabolite concentrations in guinea pigs are much lower than those seen in humans at steady state. PMID:23295923

  16. Hyperthyroidism in four guinea pigs: clinical manifestations, diagnosis, and treatment.

    PubMed

    Künzel, F; Hierlmeier, B; Christian, M; Reifinger, M

    2013-12-01

    Hyperthyroidism was diagnosed in four guinea pigs by demonstration of an increased serum total thyroxine concentration. The main clinical signs were comparable with those observed in feline hyperthyroidism and included weight loss despite maintenance of appetite and a palpable mass in the ventral cervical region. Three animals were treated successfully with methimazole for between 13 and 28 months. Clinical signs and regular measurement of circulating total thyroxine concentrations appear to be convenient parameters for monitoring response to medical therapy.

  17. Brevetoxin Depresses Synaptic Transmission in Guinea Pig Hippocampal Slices

    DTIC Science & Technology

    1993-01-01

    literature publication 4. TITLE AND SUBTITLE IS. FUNDING NUMBERS Brevetoxin depresses synpatic transmission in guinea pig hippocampal slices 61102A...The toxin produced a concentration -dependent depression of the orlhodroiiiicallk esoked population spl, , i~h an EC50 of 37 5 nM. Brevetoxin...precise mechanism b) which PbTx-3 depresses evoked responses is not certain, depolarization of the presynaptic nerve terminals leading to failure of

  18. Suppressed tuberculin reaction in guinea pigs following laser irradiation

    SciTech Connect

    Inoue, K.; Nishioka, J.; Hukuda, S.

    1989-01-01

    Tuberculin reactions were tested at the bilateral sites of the backs of sensitized guinea pigs. Laser irradiation at an energy fluence of 3.6 J at one site of reaction suppressed the reaction not only at the irradiated site but also at the contralateral nonirradiated site. These phenomena were observed when mononuclear cells were dominant in the perivascular cellular infiltration. The results indicate that local irradiation with a low-power laser has systemic inhibitory effects on delayed hypersensitivity reactions.

  19. Acute Oral Toxicity of Physostigmine Salicylate in Guinea Pigs

    DTIC Science & Technology

    1988-11-01

    of animals that died during the study presented with a serous oral discharge, perianal staining, and intussusception , observations consistent with the...receiving the lower doses. The two cases of ileocolic intussusceptions observed in animals 87E00239 and 87E00257 at necropsy is probably related to the...perioral staining and intussusception ) or common incidental findings (hepatic necrosis) of little clinical significance in guinea pigs. No evidence of direct

  20. Pharmacokinetics and pharmacodynamics of 4-aminopyridine in awake guinea pigs.

    PubMed

    Capacio, B R; Chang, F C; Spriggs, D; Byers, C E; Matthews, R L; Benton, B J

    1997-08-01

    The selective blockade of potassium channels on excitable membranes by 4-aminopyridine (4-AP) leads to facilitation of neurotransmitter release at a wide variety of synapses. This compound has been shown to be efficacious against lethality induced by saxitoxin (STX) and tetrodotoxin (TTX) in guinea pigs. To characterize the actions of 4-AP in guinea pigs we have investigated its pharmacokinetics (PK) and pharmacodynamics following a 2 mg/kg, intramuscular (im) dose in awake chronically instrumented (IN) animals. Animals were chronically instrumented for electrophysiologic recordings of diaphragmatic electromyogram (DEMG), lead II electrocardiogram (ECGII) and electrocorticogram (ECoG). Also, PK studies were carried out in uninstrumented (UN) guinea pigs. Blood and electrophysiologic data were collected at predetermined time intervals up to 4 hours post 4-AP administration. High performance liquid chromatography was used to determine plasma 4-AP concentrations. For IN and UN animals, plasma concentration-time data best fit a one-compartment model, and PK parameter estimates were similar for both groups. Peak plasma levels were found to occur between 16 and 17 min, and the half-lives of elimination were 65 and 71 min for IN and UN animals respectively. Heart and respiratory rates were elevated as early as 5 and 15 min respectively in response to 4-AP administration. The duration of action was approximately 1-1.5 half-lives of elimination beyond peak plasma levels. Maximum ECoG responses were observed between 12-15 min after 4-AP injection; some residual drug effects were still apparent at 240 min. The difference between the heart and respiratory rates and ECoG profiles suggests that these different physiological systems respond with varying degrees of sensitivity to plasma 4-AP concentrations. The stimulation of these systems is consistent with the action of 4-AP in reversing STX- and TTX-induced cardiorespiratory depression and decreased ECoG power in guinea pigs.

  1. Common Emergencies in Rabbits, Guinea Pigs, and Chinchillas.

    PubMed

    DeCubellis, Julie

    2016-05-01

    Rabbits, guinea pigs, and chinchillas are some of the more common exotic pets seen in emergency clinics. They frequently present with acute illnesses that are the result of several chronic conditions, most related to inadequate diet and husbandry. This article reviews the diagnosis and treatment of some of the more common acute illnesses. It also discusses the predisposing factors that culminate in acute presentations, so that emergency providers can recognize and be mindful of underlying causes of disease before treatment of acute illnesses.

  2. Novel antitussive effect of suplatast tosilate in guinea pigs.

    PubMed

    Zhou, Jian-Rong; Syono, Ryo-ichi; Fukumi, Syu-ichi; Kimoto, Kenji; Shirasaki, Tetsuya; Soeda, Fumio; Takahama, Kazuo

    2015-01-01

    We studied the antitussive effects of suplatast, a Th2 cytokine inhibitor, and compared them with the effects of codeine using an experimental cough model in guinea pigs. Suplatast and codeine dose-dependently inhibited cough caused by mechanical stimulation of the larynx, but they did not inhibit cough caused by mechanical stimulation of the bifurcation of the trachea. In guinea pigs with bronchitis, suplatast had an antitussive effect on cough caused by stimulation of the larynx, whereas codeine did not inhibit such cough. In SO2-exposed guinea pigs, suplatast tended to inhibit cough caused by mechanical stimulation of the tracheal bifurcation. Further, suplatast inhibited citric acid-induced cough augmented by pretreatment with an angiotensin-converting enzyme inhibitor, whereas codeine did not inhibit such cough. Suplatast also inhibited bradykinin-induced discharges of airway vagal afferent nerves and significantly inhibited 4-aminopyridine-induced discharges of airway vagal afferent nerves. These findings indicate that the antitussive effects of suplatast are mediated by a novel mechanism involving the peripheral nervous system. © 2015 S. Karger AG, Basel.

  3. Acute inhalation exposure of azodicarbonamide in the guinea pig.

    PubMed

    Shopp, G M; Cheng, Y S; Gillett, N A; Bechtold, W E; Medinsky, M A; Hobbs, C H; Birnbaum, L S; Mauderly, J L

    1987-02-01

    Humans have been exposed to azodicarbonamide (ADA) by inhalation where bulk quantities of ADA are handled in the workplace. Responses of some workers have led to concern for the potential irritant and sensitizing properties of inhaled ADA. This study examined the effects of inhaling ADA on lung structure and function of guinea pigs during and after an acute exposure. Groups of 20 guinea pigs were exposed to each of 3 concentrations of ADA (19, 58, and 97 mg/m3), plus air as a control, for 1 hr. Pulmonary function was measured before exposure (baseline), during exposure, immediately after exposure and 24 hr after exposure. Dynamic compliance (Cdyn), total pulmonary resistance (RL), tidal volume (VT), respiratory frequency and minute volume were measured. In addition, gross necropsies and histological examinations of respiratory tract tissues were done either immediately following the exposure or 24 hr after exposure. There were no effects of ADA exposure on gross necropsy, histology, Cdyn, or RL. Some significant, concentration-related decreases in VT, respiratory frequency and minute volume were seen. The magnitudes of these changes were small: the largest change was seen in minute volume, amounting to a 24% decrease in the high concentration group. Inhalation exposure of guinea pigs to ADA at concentrations of up to 97 mg/m3 resulted in minor changes in pulmonary function without any changes in lung histology.

  4. On the morality of Guinea-pig recruitment.

    PubMed

    Valdman, Mikhail

    2010-07-01

    ABSTRACT Can it be wrong to conduct medical research on human subjects even with their informed consent and even when the transaction between the subjects and researchers is expected to be mutually beneficial? This question is especially pressing today in light of the rise of a semi-professional class of 'guinea pigs'- human research subjects that sell researchers a right of access to their bodies in exchange for money. Can these exchanges be morally problematic even when they are consensual and mutually beneficial? I argue that there are two general kinds of concern one can have about such transactions - concerns about the nature of what is sold and concerns about the conditions in which the selling occurs. The former involves worries about degradation and the possible wrongness of selling a right of access to one's body. These worries, I argue, are not very serious. The latter involves worries about coercion, exploitation, and undue influence - about how, by virtue of their ignorance, impulsiveness, or desperation, guinea pigs can be taken advantage of by medical researchers. These worries are quite serious but I argue that, at least in cases where the exchange between guinea pigs and researchers is consensual and mutually beneficial, they do not raise insurmountable moral problems.

  5. Studies of guinea pig immunoglobulin isotype, idiotype and antiidiotype

    SciTech Connect

    Tirrell, S.M.

    1988-01-01

    Immunization of Guinea pigs with diphtheria toxoid generated antibodies of the IgG class that were capable of neutralizing native toxin in vivo. Sera from these animals were used to affinity purify idiotypic antibodies (AB1). AB1 vaccines derived from the IgG1 class and from F(ab{prime}){sub 2} of IgG1 + IgG2 (IgG1/2) classes were effective in inducing a syngeneic anti-idiotype (AB2) response. Animals immunized with AB1 consisting of both IgG1/2 did not elicit a detectable AB2 response. Binding of homologous {sup 125}I-F(ab{prime}){sub 2} (AB1) to the antiidiotype was inhibited 90% in the presence of DT.F(ab{prime}){sub 2} derived from preimmune serum or had no inhibitory effects on the idiotype-antiidiotype interactions. Two groups of outbred guinea pigs were vaccinated with alum absorbed F(ab{prime}){sub 2} of anti-idiotype IgG1/2 (AB2). Of the ten animals inoculated with AB2, three tested positive by RIA against {sup 125}I-DT. Two of the RIA positive sera contained antibodies that neutralized diphtheria toxin in a rabbit intracutaneous assay. Purification of guinea pig IgG by protein A-Sepharose affinity chromatography resulted in the separation of three distinct IgG populations.

  6. The origin of SFOAE microstructure in the guinea pig.

    PubMed

    Goodman, Shawn S; Withnell, Robert H; Shera, Christopher A

    2003-09-01

    Human stimulus-frequency otoacoustic emissions (SFOAEs) evoked by low-level stimuli have previously been shown to have properties consistent with such emissions arising from a linear place-fixed reflection mechanism with SFOAE microstructure thought to be due to a variation in the effective reflectance with position along the cochlea [Zweig and Shera, J. Acoust. Soc. Am. 98 (1995) 2018-2047]. Here we report SFOAEs in the guinea pig obtained using a nonlinear extraction paradigm from the ear-canal recording that show amplitude and phase microstructure akin to that seen in human SFOAEs. Inverse Fourier analysis of the SFOAE spectrum indicates that SFOAEs in the guinea pig are a stimulus level-dependent mix of OAEs arising from linear-reflection and nonlinear-distortion mechanisms. Although the SFOAEs are dominated by OAE generated by a linear-reflection mechanism at low and moderate stimulus levels, nonlinear distortion can dominate some part of, or all of, the emission spectrum at high levels. Amplitude and phase microstructure in the guinea pig SFOAE is evidently a construct of (i). the complex addition of nonlinear-distortion and linear-reflection components; (ii). variation in the effective reflectance with position along the cochlea; and perhaps (iii). the complex addition of multiple intra-cochlear reflections.

  7. Peptidoleukotriene binding in guinea pig uterine membrane preparations.

    PubMed

    Levinson, S L

    1984-08-01

    Peptidoleukotrienes are known to be potent smooth muscle contractile agents in many tissues, including guinea pig uterus. In order to characterize the receptors at which the leukotrienes interact, guinea pig uteri were homogenized in 50mM Tris-HCl, pH 7.4 at 4 degrees C and centrifuged at 1000xg for 10 min. The supernatant was centrifuged at 40,000 xg and the washed pellet was used to measure the binding of 3H-LTC4 and 3H-LTD4. Specific binding of 3H-LTD4 was not detected, but specific, saturable binding of 3H-LTC4 was measured at 4 degrees C, was complete in 10 min. and was rapidly reversible on addition of unlabeled LTC4. Binding was linear with protein concentration and stimulated by CaCl2 and L-serine borate. Scatchard and kinetic analysis of binding in the presence of calcium suggested a Kd of 10-12 nM. LTC4 was a more potent competitor of binding than LTD4 (IC50 - 40nM and 30 microM, respectively). FPL 55712 inhibited binding from 10-100 microM but stimulated binding at lower concentrations. Thus, the guinea pig uterus has specific receptors for LTC4, but not LTD4, that can be demonstrated by radioligand binding.

  8. Protection of Lassa virus-infected guinea pigs with Lassa-immune plasma of guinea pig, primate, and human origin.

    PubMed

    Jahrling, P B

    1983-01-01

    Lassa virus-immune plasma has been used to treat human Lassa fever patients; however, criteria for plasma selection were based arbitrarily on available serologic tools and protective efficacy was never directly assessed. To test the validity of plasma therapy for Lassa virus infections in an animal model, and to develop biologically relevant criteria for selection of protective immune plasma, inbred, strain 13 guinea pigs were infected with a lethal dose of Lassa virus and treated with various Lassa-immune plasmas obtained from guinea pigs, primates, and convalescent human patients. Neutralizing antibody titers were determined in a virus dilution, plaque reduction test, and were expressed as a log10 plaque-forming units (PFU) neutralization index (LNI). All guinea pigs treated with immune plasma 6 ml/kg/treatment on days 0, 3, and 6 after virus inoculation were protected, provided the LNI exceeded 2.0. Plasmas obtained from donors in early convalescence (32-45 days) had low titers of N-antibody (LNI less than 2) and failed to confer protection, despite high titers of Lassa antibody measured in the indirect fluorescent antibody (IFA) test. Higher doses of marginally titered plasma conferred increased protection. The degree of protection and suppression of viremia was closely associated with LNI an not IFA titers. Administration of low-titered plasma did not result in immune enhancement. A high dose of human plasma from Liberia (12 ml/kg/treatment) was required to confer complete protection to guinea pigs infected with a Lassa virus strain from Sierra Leone (LNI = 1.6), while a lower dose (3 ml/kg/treatment) was sufficient for protection against a Liberian strain (LNI = 2.8), suggesting that a geographic matching of immune plasma and Lassa virus strain origin may increase treatment success. These studies support the concept of plasma therapy for Lassa infection and suggest that the plaque reduction neutralization test is more appropriate than the IFA test for

  9. Biosynthesis of factor V in isolated guinea pig megakaryocytes.

    PubMed Central

    Chiu, H C; Schick, P K; Colman, R W

    1985-01-01

    Although platelets contain Factor V, localized primarily in the alpha-granules, the origin of this coagulation cofactor in these cells is not known. We therefore explored whether isolated megakaryocytes could biosynthesize Factor V. Guinea pig plasma Factor V coagulant activity was demonstrated to be neutralized by human monoclonal and rabbit polyclonal antibodies directed monospecifically against human Factor V. These antibodies had been used earlier to purify human Factor V. These antibodies had been used earlier to purify human Factor V and to quantify Factor V antigen concentration, respectively (1983. Chiu, H. C., E. Whitaker, and R. W. Colman. J. Clin. Invest. 72:493-503). As determined by a competitive enzyme-linked immunosorbent assay with guinea pig plasma as a standard, Factor V solubilized from guinea pig megakaryocytes was present at 0.098 +/- 0.018 micrograms/10(5) cells. Each megakaryocyte contained about 500 times as much Factor V as is in a platelet (0.234 +/- 0.180 micrograms/10(8) platelets). The content of Factor V antigen in guinea pig plasma was greater (27.0 +/- 3.0 micrograms/ml) than that of Factor V antigen in human plasma (11.1 +/- 0.4 micrograms/ml). In contrast, human platelets contain ninefold more Factor V antigen (2.01 +/- 1.09 micrograms/10(8) platelets) than do guinea pig were 2.85 +/- 0.30 U/ml plasma, 0.022 +/- 0.012 U/10(8) platelets, and 0.032 +/- 0.03 U/10(5) megakaryocytes, compared with human values of 0.98 +/- 0.02 U/ml plasma and 0.124 +/- 0.064 U/10(8) platelets. Isolated megakaryocytes were found to contain Factor V by cytoimmunofluorescence. The megakaryocytes were incubated with [35S]methionine, and radiolabeled intracellular proteins purified were on a human anti-Factor V immunoaffinity column. The purified protein exhibited Factor V coagulant activity and neutralized the inhibitory activity of a rabbit antihuman Factor V antibody, which suggests that megakaryocyte Factor V is functionally and antigenically intact

  10. Effect of organic selenium supplementation on growth, Se uptake, and nutrient utilization in guinea pigs.

    PubMed

    Chaudhary, Mahima; Garg, Anil Kumar; Mittal, Ganesh Kumar; Mudgal, Vishal

    2010-02-01

    Forty weaned male guinea pigs (Cavia porcellus) of 152.6 +/- 7.96 g mean body weight were divided into four equal groups and fed a common basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), and ascorbic acid at 200 mg/kg to meet their nutrient requirements along with 0, 0.1, 0.2, and 0.3 ppm of organic selenium (Se) in groups I, II, III, and IV, respectively. Experimental feeding lasted for a period of 10 weeks, during which, daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber, and nitrogen-free extract as well as uptake of calcium and phosphorus were similar (P > 0.05) among the four groups. Feed:gain ratio was also similar (P > 0.05) in the four groups. However, digestibility of crude protein was significantly (P < 0.001) higher in group II supplemented with 0.1 ppm organic Se as compared to other three group. Intake and absorption of Se was significantly (P < 0.001) higher in all the Se supplemented groups as compared to control group. Average daily gain (ADG) was significantly (P < 0.05) higher in group II (3.16 g/day) and III (3.38 g/day) as compared to group I (2.88 g/day). However, ADG in group IV (supplemented 0.3 ppm organic Se) was significantly (P < 0.05) lower (2.83 g/day) than group II and III, but comparable (P > 0.05) to group I. Findings of the present experiment suggests that Se requirements of guinea pigs are > or =0.2 ppm, as supplementation of 0.1 ppm organic Se in the diet (having 0.1 ppm Se) not only enhanced their growth rate but also improved the protein utilization.

  11. THE EFFECT OF 6-MERCAPTOPURINE ON DELAYED HYPERSENSITIVITY IN GUINEA PIGS

    PubMed Central

    Hoyer, John R.; Hoyer, Leon W.; Good, Robert A.; Condie, Richard M.

    1962-01-01

    The development of tuberculin hypersensitivity in guinea pigs after BCG stimulation was suppressed by intramuscular administration of 50 mg/kg/day of 6-mercaptopurine started at the time of stimulation. Fasting of guinea pigs after BCG stimulation had no effect on the development of tuberculin hypersensitivity. PMID:13955205

  12. Development of a Method to Determine the Audiogram of the Guinea Pig for Threshold Shift Studies,

    DTIC Science & Technology

    1984-01-01

    52 kHz by using a positive reinforcement training method. In this procedure, tones served as discriminative stimuli for a report response. Guinea pigs...and Stebbins, W. C. 1978. Auditory thresholds and kanamycin-induced hearing loss in the guinea pig assessed by a positive reinforcement procedure

  13. Attempt to immunize guinea pigs against leukemia by skin scarification with leukemic cell suspensions.

    PubMed

    Gross, L

    1973-12-01

    An attempt was made to immunize "strain 2" guinea pigs by superficial skin scarification with small doses of L2C leukemic cell suspensions. Among 203 scarified guinea pigs, 32 developed progressively growing leukemic tumors at the site of skin scarification. In 35 guinea pigs small intradermal tumors that appeared at the site of scarification regressed spontaneously; however, 15 guinea pigs in which the intradermal tumor regressed later developed generalized leukemia. In addition, 13 other animals developed generalized leukemia, without an apparent local tumor formation at the site of scarification. A total of 60 out of 203 scarified guinea pigs (30%) died from leukemia.143 Guinea pigs that survived the scarification were challenged by subcutaneous inoculation of massive doses (0.5 ml each of a 10-fold dilution from a 10% extract) of leukemic cell extracts and only 48 (34%) developed leukemia; 95 guinea pigs (66%) resisted the challenge and remained in good health. In a control experiment, 156 untreated "strain 2" guinea pigs were inoculated subcutaneously (0.5 ml each) with L2C leukemic cell suspensions of 10(-2) or 10(-3) dilution, and all but two (99%) developed generalized leukemia.

  14. Attempt to Immunize Guinea Pigs Against Leukemia by Skin Scarification with Leukemic Cell Suspensions

    PubMed Central

    Gross, Ludwik

    1973-01-01

    An attempt was made to immunize “strain 2” guinea pigs by superficial skin scarification with small doses of L2C leukemic cell suspensions. Among 203 scarified guinea pigs, 32 developed progressively growing leukemic tumors at the site of skin scarification. In 35 guinea pigs small intradermal tumors that appeared at the site of scarification regressed spontaneously; however, 15 guinea pigs in which the intradermal tumor regressed later developed generalized leukemia. In addition, 13 other animals developed generalized leukemia, without an apparent local tumor formation at the site of scarification. A total of 60 out of 203 scarified guinea pigs (30%) died from leukemia. 143 Guinea pigs that survived the scarification were challenged by subcutaneous inoculation of massive doses (0.5 ml each of a 10-fold dilution from a 10% extract) of leukemic cell extracts and only 48 (34%) developed leukemia; 95 guinea pigs (66%) resisted the challenge and remained in good health. In a control experiment, 156 untreated “strain 2” guinea pigs were inoculated subcutaneously (0.5 ml each) with L2C leukemic cell suspensions of 10-2 or 10-3 dilution, and all but two (99%) developed generalized leukemia. Images PMID:4519636

  15. Rapid Accumulation of Eosinophils in Lung Lesions in Guinea Pigs Infected with Mycobacterium tuberculosis

    PubMed Central

    Lasco, Todd M.; Turner, Oliver C.; Cassone, Lynne; Sugawara, Isamu; Yamada, Hiroyuki; McMurray, David N.; Orme, Ian M.

    2004-01-01

    Guinea pig eosinophils were positively identified in bronchoalveolar lavage populations and in the lung granulomas of Mycobacterium tuberculosis-infected guinea pigs. It is possible that the rapid influx of these cells, and their subsequent degranulation during acute pulmonary tuberculosis, may play a key role in the susceptibility of this animal model. PMID:14742563

  16. The innate immunity of guinea pigs against highly pathogenic avian influenza virus infection.

    PubMed

    Zhang, Kun; Xu, Wei Wei; Zhang, Zhaowei; Liu, Jing; Li, Jing; Sun, Lijuan; Sun, Weiyang; Jiao, Peirong; Sang, Xiaoyu; Ren, Zhiguang; Yu, Zhijun; Li, Yuanguo; Feng, Na; Wang, Tiecheng; Wang, Hualei; Yang, Songtao; Zhao, Yongkun; Zhang, Xuemei; Wilker, Peter R; Liu, WenJun; Liao, Ming; Chen, Hualan; Gao, Yuwei; Xia, Xianzhu

    2017-05-02

    H5N1 avian influenza viruses are a major pandemic concern. In contrast to the highly virulent phenotype of H5N1 in humans and many animal models, guinea pigs do not typically display signs of severe disease in response to H5N1 virus infection. Here, proteomic and transcriptional profiling were applied to identify host factors that account for the observed attenuation of A/Tiger/Harbin/01/2002 (H5N1) virulence in guinea pigs. RIG-I and numerous interferon stimulated genes were among host proteins with altered expression in guinea pig lungs during H5N1 infection. Overexpression of RIG-I or the RIG-I adaptor protein MAVS in guinea pig cell lines inhibited H5N1 replication. Endogenous GBP-1 expression was required for RIG-I mediated inhibition of viral replication upstream of the activity of MAVS. Furthermore, we show that guinea pig complement is involved in viral clearance, the regulation of inflammation, and cellular apoptosis during influenza virus infection of guinea pigs. This work uncovers features of the guinea pig innate immune response to influenza that may render guinea pigs resistant to highly pathogenic influenza viruses.

  17. Dioxin in soil: bioavailability after ingestion by rats and guinea pigs

    SciTech Connect

    McConnell, E.E.; Lucier, G.W.; Rumbaugh, R.C.; Albro, P.W.; Harvan, D.J.; Hass, J.R.; Harris, M.W.

    1984-03-09

    Soil environmentally contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was given by gavage to guinea pigs and rats. The development of a characteristic clinicopathologic syndrome in guinea pigs, the induction of aryl hydrocarbon hydroxylase in rats, and the presence of TCDD in the livers of both species show that TCDD in soil exhibits high biological availability after ingestion.

  18. The innate immunity of guinea pigs against highly pathogenic avian influenza virus infection

    PubMed Central

    Zhang, Kun; wei Xu, Wei; Zhang, Zhaowei; liu, Jing; Li, Jing; Sun, Lijuan; Sun, Weiyang; Jiao, Peirong; Sang, Xiaoyu; Ren, Zhiguang; Yu, Zhijun; Li, Yuanguo; Feng, Na; Wang, Tiecheng; Wang, Hualei; Yang, Songtao; Zhao, Yongkun; Zhang, Xuemei; Wilker, Peter R.; Liu, WenJun; Liao, Ming; Chen, Hualan; Gao, Yuwei; Xia, Xianzhu

    2017-01-01

    H5N1 avian influenza viruses are a major pandemic concern. In contrast to the highly virulent phenotype of H5N1 in humans and many animal models, guinea pigs do not typically display signs of severe disease in response to H5N1 virus infection. Here, proteomic and transcriptional profiling were applied to identify host factors that account for the observed attenuation of A/Tiger/Harbin/01/2002 (H5N1) virulence in guinea pigs. RIG-I and numerous interferon stimulated genes were among host proteins with altered expression in guinea pig lungs during H5N1 infection. Overexpression of RIG-I or the RIG-I adaptor protein MAVS in guinea pig cell lines inhibited H5N1 replication. Endogenous GBP-1 expression was required for RIG-I mediated inhibition of viral replication upstream of the activity of MAVS. Furthermore, we show that guinea pig complement is involved in viral clearance, the regulation of inflammation, and cellular apoptosis during influenza virus infection of guinea pigs. This work uncovers features of the guinea pig innate immune response to influenza that may render guinea pigs resistant to highly pathogenic influenza viruses. PMID:28418930

  19. Morphologic investigations of the guinea pig model of iron overload.

    PubMed

    Schwartz, K A; Fisher, J; Adams, E T

    1993-01-01

    We have developed a guinea pig model of iron overload toxicity. Animals were administered intraperitoneal iron dextran 3 times a week to achieve total body iron load of 0.25, 0.5, 1.0, 1.5, and 2.0 g Fe/kg body weight in less than 30 days. Quantitation of tissue iron levels with atomic absorption indicated increased iron deposition in liver and heart of the iron-loaded guinea pigs (p < 0.001). Additionally, the iron-loaded pigs demonstrated decreased nuclear magnetic resonance spectroscopy T1 relaxation times in both liver and heart (p < 0.001). Serum iron, total body iron capacity, and transferrin saturation values were also determined in guinea pigs treated with 0.25, 0.5, and 1.0 g Fe/kg body weight. Serum iron and total iron-binding capacity were significantly increased at 0.5 and 1.0 g Fe/kg; transferrin saturation was elevated at 0.25 and 1.0 g Fe/kg. kg. Histologic examination of liver, heart, and bone marrow as well as ultrastructural studies on liver and heart confirmed increased iron deposition in treated animals. At the low iron dose level of 0.5 g Fe/kg, liver iron particles were primarily confined to Kupffer cells with minimal hepatocellular localization. Increased hepatocellular iron deposition was observed with larger doses of loaded iron. Myocardial iron was most prominent in interstitial cells of the epicardium, endocardium, myocardium, and coronary adipose tissue. Ultrastructurally, the presence of iron particles in perinuclear, membrane-bound structures (consistent with lysosomes) was confirmed using x-ray microanalysis. These morphological studies suggest that in this animal model siderosis of hepatic mononuclear phagocyte and myocardial interstitial cells may be the initial lesions leading to further biochemical and functional abnormalities. Correlation between tissue iron measurements and both light and electron microscopic changes, presented in this report, serve to introduce the iron-loaded guinea pig as a model for the study of iron

  20. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs.

    PubMed

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico; Page, Clive

    2016-04-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  1. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs

    PubMed Central

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico

    2016-01-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs. PMID:26837703

  2. Ciliary Muscle Cell Changes During Guinea Pig Development

    PubMed Central

    Pucker, Andrew D.; Jackson, Ashley R.; Morris, Hugh J.; Fischer, Andrew J.; McHugh, Kirk M.; Mutti, Donald O.

    2015-01-01

    Purpose Guinea pig ciliary muscle (CM) increases robustly in volume, length, and thickness with age. We wanted to characterize CM cells during development to determine the contributions of hypertrophy (cell size increase) and hyperplasia (cell number increase) during development. Methods Six pigmented guinea pig eyes were collected at each of five ages: 1, 10, 20, 30, and 90 days. Refractive errors and axial lengths were determined. Eyes were temporally marked, enucleated, hemisected, and fixed. Nasal and temporal eye segments were embedded and 30-μm serial sections were collected; the two most central slides from each hemisection were analyzed with an epifluorescence microscope and Stereo Investigator software to determine normal morphologic parameters. Results Refractive errors became less hyperopic (P = 0.0001) while axial lengths and CM lengths, cross-sectional areas, volumes, and cell sizes all increased linearly with log age (all P < 0.00001). Ciliary muscle cell numbers increased only during the first 20 days of life (P = 0.02). Nasal and temporal CM lengths (P = 0.07), cross-sectional areas (P = 0.18), and cell numbers (P = 0.70) were not different, but CM cell sizes were initially larger temporally and became larger nasally after age 30 days. Conclusions The mechanism of guinea pig CM cell growth during the first 90 days of life was characterized by early hyperplasia combined with hypertrophic cell growth throughout development that results in larger CM lengths, cross-sectional areas, and volumes. Nasal-temporal CM development was generally symmetric, but there was more CM hypertrophy nasally at older ages. PMID:26641547

  3. Bronchodilator action of inhaled nitric oxide in guinea pigs.

    PubMed Central

    Dupuy, P M; Shore, S A; Drazen, J M; Frostell, C; Hill, W A; Zapol, W M

    1992-01-01

    The effects of inhaling nitric oxide (NO) on airway mechanics were studied in anesthetized and mechanically ventilated guinea pigs. In animals without induced bronchoconstriction, breathing 300 ppm NO decreased baseline pulmonary resistance (RL) from 0.138 +/- 0.004 (mean +/- SE) to 0.125 +/- 0.002 cmH2O/ml.s (P less than 0.05). When an intravenous infusion of methacholine (3.5-12 micrograms/kg.min) was used to increase RL from 0.143 +/- 0.008 to 0.474 +/- 0.041 cmH2O/ml.s (P less than 0.05), inhalation of 5-300 ppm NO-containing gas mixtures produced a dose-related, rapid, consistent, and reversible reduction of RL and an increase of dynamic lung compliance. The onset of bronchodilation was rapid, beginning within 30 s after commencing inhalation. An inhaled NO concentration of 15.0 +/- 2.1 ppm was required to reduce RL by 50% of the induced bronchoconstriction. Inhalation of 100 ppm NO for 1 h did not produce tolerance to its bronchodilator effect nor did it induce substantial methemoglobinemia (less than 2%). The bronchodilating effects of NO were additive with the effects of inhaled terbutaline, irrespective of the sequence of NO and terbutaline administration. Inhaling aerosol generated from S-nitroso-N-acetylpenicillamine also induced a rapid and profound decrease of RL from 0.453 +/- 0.022 to 0.287 +/- 0.022 cmH2O/ml.s, which lasted for over 15 min in guinea pigs broncho-constricted with methacholine. Our results indicate that low levels of inhaled gaseous NO, or an aerosolized NO-releasing compound are potent bronchodilators in guinea pigs. PMID:1644915

  4. Attenuation of streptomycin ototoxicity by tetramethylpyrazine in guinea pig cochlea.

    PubMed

    Cui, Cheng; Liu, Dajun; Qin, Xin

    2015-05-01

    Tetramethylpyrazine has been suggested to have a therapeutic effect on impaired hearing that is induced by aminoglycoside antibiotics. However, its effectiveness on streptomycin ototoxicity and its cellular mechanisms are relatively unknown. Here we investigate the protective effect of tetramethylpyrazine on streptomycin-induced ototoxicity in guinea pig cochlea. Prospective randomized laboratory study. Hearing Research Laboratory of China Medical University. Adult guinea pigs were randomized to 4 groups. Hearing sensitivity of guinea pigs was tested by auditory brainstem response measurements before streptomycin exposure and again 10 days later. The cochlear tissues were prepared for electron microscopy and immunohistochemical staining of heat shock protein 70 (HSP70). The effect of tetramethylpyrazine on streptomycin-induced activation of caspase-3 was evaluated by Western blotting. Co-therapy with tetramethylpyrazine reduced a profound streptomycin-induced auditory threshold shift compared with streptomycin treatment alone (P = .0002 or P = .00008). Tetramethylpyrazine also attenuated the structural disruption in streptomycin-treated outer hair cells and marginal cells of vascular stria by transmission electronic microscopy and scanning electronic microscopy, respectively. Moreover, tetramethylpyrazine decreased the streptomycin-stimulated expressions of HSP70 and caspase-3. The correlation analysis demonstrated that HSP70 expression had a positive correlation with auditory brainstem response thresholds (|R| = 0.6-0.9, P = .0073 or P = .0169). Our data suggest that the protective effect of tetramethylpyrazine on hearing function is associated with the reduction of stress response and inhibition of apoptosis. Tetramethylpyrazine may have therapeutic potential for patients with ototoxicity diseases. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

  5. Cavia porcellus as a Model for Experimental Infection by Trypanosoma cruzi

    PubMed Central

    Castro-Sesquen, Yagahira E.; Gilman, Robert H.; Yauri, Verónica; Angulo, Noelia; Verastegui, Manuela; Velásquez, Daniel E.; Sterling, Charles R.; Martin, Diana; Bern, Caryn

    2011-01-01

    The guinea pig (Cavia porcellus) is a natural reservoir for Trypanosoma cruzi but has seldom been used as an experimental infection model. We developed a guinea pig infection model for acute and chronic Chagas disease. Seventy-two guinea pigs were inoculated intradermally with 104 trypomastigotes of T. cruzi strain Y (experimental group); 18 guinea pigs were used as control group. Eight animals from the experimental group and two from the control group were sacrificed 5, 15, 20, 25, 40, 55, 115, 165, and 365 days after inoculation. During the acute phase (15 to 55 days), we observed parasitemia (with a peak on day 20) and positive IgM and IgG Western blots with anti-shed acute-phase antigen bands. The cardiac tissue showed vasculitis, necrosis (on days 40 to 55), moderate to severe inflammation, and abundant amastigote nests. Smaller numbers of amastigote nests were also present in kidney, brain, and other organs. In the early chronic phase (115 to 165 days), parasitemia disappeared and anti–T. cruzi IgG antibodies were still detectable. In cardiac tissue, the number of amastigote nests and the grade of inflammation decreased. In the chronic phase (365 days), the cardiac tissue showed vasculitis and fibrosis; detectable parasite DNA was associated with higher grades of inflammation. The experimental T. cruzi infection model in guinea pigs shows kinetics and pathologic changes similar to those of the human disease. PMID:21703410

  6. Cavia porcellus as a model for experimental infection by Trypanosoma cruzi.

    PubMed

    Castro-Sesquen, Yagahira E; Gilman, Robert H; Yauri, Verónica; Angulo, Noelia; Verastegui, Manuela; Velásquez, Daniel E; Sterling, Charles R; Martin, Diana; Bern, Caryn

    2011-07-01

    The guinea pig (Cavia porcellus) is a natural reservoir for Trypanosoma cruzi but has seldom been used as an experimental infection model. We developed a guinea pig infection model for acute and chronic Chagas disease. Seventy-two guinea pigs were inoculated intradermally with 10(4) trypomastigotes of T. cruzi strain Y (experimental group); 18 guinea pigs were used as control group. Eight animals from the experimental group and two from the control group were sacrificed 5, 15, 20, 25, 40, 55, 115, 165, and 365 days after inoculation. During the acute phase (15 to 55 days), we observed parasitemia (with a peak on day 20) and positive IgM and IgG Western blots with anti-shed acute-phase antigen bands. The cardiac tissue showed vasculitis, necrosis (on days 40 to 55), moderate to severe inflammation, and abundant amastigote nests. Smaller numbers of amastigote nests were also present in kidney, brain, and other organs. In the early chronic phase (115 to 165 days), parasitemia disappeared and anti-T. cruzi IgG antibodies were still detectable. In cardiac tissue, the number of amastigote nests and the grade of inflammation decreased. In the chronic phase (365 days), the cardiac tissue showed vasculitis and fibrosis; detectable parasite DNA was associated with higher grades of inflammation. The experimental T. cruzi infection model in guinea pigs shows kinetics and pathologic changes similar to those of the human disease. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  7. Auditory effects of noise on infant and adult guinea pigs.

    PubMed

    Danto, J; Caiazzo, A J

    1977-01-01

    This pilot study compared the susceptibility of the infant (48 hr) and adult (120 days) guinea pig to the effects of noise. Subjects were exposed to a narrow band of noise (center frequency 4 kHz) at an intensity of 115 dB sound pressure level (SPL) for 1 hr. Postexposure thresholds were obtained by a conditioned suppression technique. Results indicated that the infant animals displayed a mean hearing threshold of 25 dB SPL that significantly differed from the adult mean threshold of 7.5 dB SPL.

  8. Antimicrobial therapy of experimental Legionella micdadei pneumonia in guinea pigs.

    PubMed Central

    Pasculle, A W; Dowling, J N; Frola, F N; McDevitt, D A; Levi, M A

    1985-01-01

    Several antimicrobial agents were evaluated for activity against experimental Legionella micdadei pneumonia in guinea pigs. Erythromycin, rifampin, doxycycline, and sulfamethoxazole-trimethoprim produced significant reductions in mortality. Penicillin, cefazolin, cefoxitin, chloramphenicol, and gentamicin were not efficacious even though, at the doses administered, the peak concentrations of these agents in serum substantially exceeded their MICs for the test strain. It is suggested that the poor performance of the latter group of agents resulted from poor penetration into cells in which L. micdadei was multiplying. PMID:3878688

  9. Early histological maturation in the hippocampus of the guinea pig.

    PubMed

    Nacher, J; Palop, J J; Ramirez, C; Molowny, A; Lopez-Garcia, C

    2000-06-01

    The vesicular zinc-rich synaptic systems of the principal neurons of the hippocampus are well developed in newborn guinea pigs, a precocial species. In addition, alvear and fimbrial myelinated fibers as well as significant inhibitory interneurons (i.e. somatostatin, parvalbumin and opioid immunoreactive hippocampal interneurons) are also well developed. On the contrary, neither vesicular zinc synapses nor myelinated fibers nor the above mentioned immunoreactive interneurons are detectable in newborn specimens of other related altricial species such as rats or rabbits. These data suggest that early maturation of a highly integrative center related to cognitive map building such as the hippocampus is characteristic of precocial species.

  10. The present use of guinea pigs for chiropractic research *

    PubMed Central

    McGregor, Marion; Wiles, Michael R.; Grice, Adrian S.

    1980-01-01

    The necessity for an animal model in chiropractic research is considered and a short review of previous experimentation of manipulation on animals is presented. The guinea pig is proposed as a suitable animal model, and research into its suitability is presented. Analysis includes the animal’s physical characteristics, the choice of anesthetic and parametric and roentgenographic evaluation. A device for supporting the anesthetized animal during standard and motion roentgenographic examination is described. We conclude that this animal model fulfills the requirements necessary for successful investigation in chiropractic research, and the need for such investigation is emphasized. ImagesFigure 1Figure 2

  11. Microbial flora of odontogenic abscesses in pet guinea pigs.

    PubMed

    Minarikova, A; Hauptman, K; Knotek, Z; Jekl, V

    2016-10-01

    Abscesses of odontogenic origin in guinea pigs pose a serious health problem and need to be treated with a combination of surgical and medical therapy. The aim of this prospective study was to describe the microbial flora of odontogenic abscesses associated with osteomyelitis in 24 pet guinea pigs, to perform antibiotic sensitivity testing, and to make recommendations for practitioners on the antibiotics of first choice. Inclusion criteria for the study included the animal being diagnosed with an odontogenic abscess which underwent surgery and was not pre-treated with an antibiotic. Inclusion criteria matched for 24 guinea pigs. Samples (pus, capsule and affected tooth/bone) for bacteriological examination were collected under sterile conditions during the surgical procedure. The most commonly isolated bacteria from abscesses of odontogenic origin were Bacteroides fragilis in 12.8 per cent (6/47) of cases, Pasteurella multocida in 10.6 per cent (5/47) and Peptostreptococcus anaerobius in 8.5 per cent (4/47). Aerobic bacterial species only were isolated in 29.2 per cent (7/24) of cases, anaerobic bacteria only were isolated in 33.3 per cent (8/24), and mixed infection with anaerobic and aerobic bacterial species was seen in 37.5 per cent (9/24). Aerobes (n=20) were sensitive to enrofloxacin and marbofloxacin in 100 per cent of samples, benzylpenicillin potassium (penicillin G, PNCG) in 90 per cent, cephalotin in 85 per cent, amoxicillin-clavulanate in 75 per cent, doxycycline in 70 per cent, gentamicin in 65 per cent and trimethoprim-sulfamethoxazole in 55 per cent. Anaerobes (n=27) were sensitive to amoxicillin-clavulanate in 100 per cent of cases, clindamycin in 96.3 per cent, metronidazole in 92.6 per cent, PNCG in 92.6 per cent and cephalotin in 74.1 per cent. As guinea pigs are strictly herbivorous animals, based on the results of this study the recommended antibiotic treatment for odontogenic abscesses is a combination of fluoroquinolones and metronidazole

  12. Effect of Inflammatory Response on In Vivo Competition between Two Chlamydial Variants in the Guinea Pig Model of Inclusion Conjunctivitis

    PubMed Central

    Bowlin, Anne K.; Tormanen, Kati I.; Wang, Yin; Maurelli, Anthony T.

    2012-01-01

    In order to study the interaction of variants in in vivo infection, we employed an azithromycin-resistant mutant (AZ2) and its wild-type parent (SP6) in the guinea pig model of Chlamydia caviae conjunctival infection. When each strain was inoculated individually into conjunctiva, both attained the same level of growth, but AZ2 elicited less pathology. However, when equal numbers of the two strains were inoculated together into the guinea pig conjunctiva, SP6 produced a significantly greater number of inclusion-forming units than AZ2, and the pathology reflected that of a SP6 monoinfection. The goal of this study was to further characterize the dynamics of concomitant infection of these two distinct variants, with particular emphasis on the impact of the host response on the in vivo growth of each organism and the development of pathology. Animals infected with AZ2 had reduced conjunctival infiltration with CD45+ cells and neutrophils as well as a reduced interleukin-8 (IL-8) response. Gene expression of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), CCL2, and CCL5 was also significantly lower in AZ2-infected animals. The lower inflammatory response induced by AZ2 was associated with its decreased ability to activate NF-κB via Toll-like receptor 2 (TLR2). In general, the inflammatory response in animals infected with both variants was greater than in infection with AZ2 alone, resulting in lower numbers of AZ2 than those of SP6 in the mixed infection. Our results suggest that the ability to elicit an inflammatory response is an important factor in the dynamics of mixed infection with strains that display different pathological phenotypes. PMID:22144478

  13. Effect of inflammatory response on in vivo competition between two chlamydial variants in the guinea pig model of inclusion conjunctivitis.

    PubMed

    Rank, Roger G; Bowlin, Anne K; Tormanen, Kati I; Wang, Yin; Maurelli, Anthony T

    2012-02-01

    In order to study the interaction of variants in in vivo infection, we employed an azithromycin-resistant mutant (AZ(2)) and its wild-type parent (SP(6)) in the guinea pig model of Chlamydia caviae conjunctival infection. When each strain was inoculated individually into conjunctiva, both attained the same level of growth, but AZ(2) elicited less pathology. However, when equal numbers of the two strains were inoculated together into the guinea pig conjunctiva, SP(6) produced a significantly greater number of inclusion-forming units than AZ(2), and the pathology reflected that of a SP(6) monoinfection. The goal of this study was to further characterize the dynamics of concomitant infection of these two distinct variants, with particular emphasis on the impact of the host response on the in vivo growth of each organism and the development of pathology. Animals infected with AZ(2) had reduced conjunctival infiltration with CD45(+) cells and neutrophils as well as a reduced interleukin-8 (IL-8) response. Gene expression of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), CCL2, and CCL5 was also significantly lower in AZ(2)-infected animals. The lower inflammatory response induced by AZ(2) was associated with its decreased ability to activate NF-κB via Toll-like receptor 2 (TLR2). In general, the inflammatory response in animals infected with both variants was greater than in infection with AZ(2) alone, resulting in lower numbers of AZ(2) than those of SP(6) in the mixed infection. Our results suggest that the ability to elicit an inflammatory response is an important factor in the dynamics of mixed infection with strains that display different pathological phenotypes.

  14. Paternal heat exposure causes DNA methylation and gene expression changes of Stat3 in Wild guinea pig sons.

    PubMed

    Weyrich, Alexandra; Benz, Stephanie; Karl, Stephan; Jeschek, Marie; Jewgenow, Katarina; Fickel, Joerns

    2016-05-01

    Epigenetic mechanisms convey environmental information through generations and can regulate gene expression. Epigenetic studies in wild mammals are rare, but enable understanding adaptation processes as they may occur in nature. In most wild mammal species, males are the dispersing sex and thus often have to cope with differing habitats and thermal changes more rapidly than the often philopatric females. As temperature is a major environmental selection factor, we investigated whether genetically heterogeneous Wild guinea pig (Cavia aperea) males adapt epigenetically to an increase in temperature, whether that response will be transmitted to the next generation(s), and whether it regulates mRNA expression. Five (F0) adult male guinea pigs were exposed to an increased ambient temperature for 2 months, corresponding to the duration of the species' spermatogenesis. To study the effect of heat, we focused on the main thermoregulatory organ, the liver. We analyzed CpG-methylation changes of male offspring (F1) sired before and after the fathers' heat treatment (as has recently been described in Weyrich et al. [Mol. Ecol., 2015]). Transcription analysis was performed for the three genes with the highest number of differentially methylated changes detected: the thermoregulation gene Signal Transducer and Activator of Transcription 3 (Stat3), the proteolytic peptidase gene Cathepsin Z (Ctsz), and Sirtuin 6 (Sirt6) with function in epigenetic regulation. Stat3 gene expression was significantly reduced (P < 0.05), which indicated a close link between CpG-methylation and expression levels for this gene. The two other genes did not show gene expression changes. Our results indicate the presence of a paternal transgenerational epigenetic effect. Quick adaptation to climatic changes may become increasingly relevant for the survival of wildlife species as global temperatures are rising.

  15. Non-invasive Serial Blood Collection in Guinea Pigs (Cavia porcellus)

    DTIC Science & Technology

    2007-07-01

    NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Adkins, AL, Moran, AV 5d. PROJECT NUMBER 5e. TASK NUMBER 6.2 5f. WORK UNIT ...technicians. The toenail clip method provided an easily trained, easily performed method of blood collection that yielded up to one milliliter of blood...collection, toenail clips, toenail bleeds 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF

  16. Cutaneous sensitization to some polyisocyanate prepolymers in guinea pigs.

    PubMed

    Zissu, D; Binet, S; Limasset, J C

    1998-11-01

    Isocyanates are used extensively in the polyurethane industry. Pulmonary and dermal sensitization resulting from exposure to diisocyanates has frequently been reported, but the potential effects of polyisocyanates on health are less well known. Thus, since 1978, occupational exposure limits have been established for diisocyanates only. Nevertheless, respiratory diseases and dermatitis have been reported in the polyurethane industry after accidental isocyanate contact during spills or splashes. The aim of this experimental work was to assess the dermal hypersensitivity of guinea pigs to some polyisocyanate prepolymers by means of a well-conducted standard predictive Buehler test. Our results showed that dicyclohexylmethane 4,4'-diisocyanate (HMDI), toluylene 2,4-diisocyanate (TDI), TDI adduct triol, TDI isocyanurate, 1,6-hexamethylene diisocyanate (HDI), HDI isocyanurate, HDI biuret and isophorone diisocyanate (IPDI) induced dermal sensitization while IPDI isocyanurate did not. In conclusion, the dermal hypersensitivity of guinea pigs to some polyisocyanates was similar to those of their corresponding monomers except for IPDI isocyanurate, suggesting that the results from diisocyanate monomers could not be a valuable approach for the detection of the sensitization potency of the corresponding prepolymers.

  17. Acid secretion by guinea-pig isolated stomach.

    PubMed Central

    Holton, P; Spencer, J

    1976-01-01

    An isolated stomach preparation from the guinea-pig is described. 2. Both histamine acid phosphate (1-4 mug/ml.) and theophylline hydrate (0-2-3-2 mg/ml.) separately stimulated hydrochloric acid, HCl, secretion from the guinea-pig stomach preparation. A linear dose-response relationship was obtained for theophylline. 3. Addition of theophylline (0-2 and 1-6 mg/ml.) during maximal response to histamine increased the secretion further, whereas addition of histamine during maximal response to theophylline did not cause further secretion. 4. The secretory activities of Nalpha-MeH (0-3-5-0 muM), Nalpha-Me2H (1-2-9-5 muM) and 5-MeH (1-5-12 muM) were compared with histamine (0-9-13 muM) on a threshold background secretion induced by theophylline (0-2 mg/ml.). Linear log.-dose response relationships were obtained for each test drug. The results confirm that Nalpha-MeH is a more potent secretagogue than histamine. 5. Pentagastrin (0-3-1-0 mug/ml.) stimulated HCl secretion in approximately half the experiments. The response was often transitory. In the other experiments, pentagastrin had no effect on HCl secretion although subsequent administration of histamine did stimulate HCl secretion. PMID:3644

  18. Pulmonary effects of acid sulfate inhalation in the guinea pig

    SciTech Connect

    Silbaugh, S.A.; Mauderly, J.L.; Wolff, R.K.; Carpenter, R.L.; Brownstein, D.G.; Harkema, J.R.; Rothenberg, S.J.

    1982-07-01

    Guinea pigs were exposed by inhalation for 1 to 8 hours to sulfuric acid aerosols of various sizes and concentrations in order to provide quantitative information for standards setting. The effects of sulfuric acid aerosols were examined to determine acute mortality, changes in respiratory function and morphology, response mechanisms, differences in individual sensitivity and changes in airway response to bronchoconstrictors. An aerosol generator for another sulfur-containing pollutant, ammonium bisulfite, was developed for use in animal exposures. Also, lung lesions which simulate human emphysema were produced by intratracheal elastase instillation to investigate a potential impaired animal model for sulfur pollutant exposures. Pulmonary mechanics, lung morphology, and histamine sensitivity data all suggest that the guinea pig reacts to sulfuric acid aerosols with a nearly all-or-none airway constrictive response. Results also indicate that the concentration at which this response occurs is affected by aerosol size, exposure profile and individual animal sensitivity. No acute pulmonary function changes were noted at concentrations below 15 mg/m/sup 3/. The reason for these differences is unknown.

  19. Noninvasive detection of airway constriction in awake guinea pigs

    SciTech Connect

    Silbaugh, S.A.; Mauderly, J.L.

    1984-01-01

    Tidal volume measured by the barometric method is very sensitive to increases in compression and expansion of alveolar gas, such as would be expected to occur during airway narrowing or closure. By comparing a barometric method tidal volume signal (VT') with a reference tidal volume (VT) obtained with a head-out pressure plethysmograph, a simple index related to gas compressibility effects was calculated (VT/VT'). Changes in this index were compared with decreases in dynamic compliance (Cdyn) during histamine aerosol challenge of 15 Charles River Hartley guinea pigs. Decreases in VT/VT' occurred during all aerosol challenges and were correlated with decreases in Cdyn. Decreases in VT/VT' were most marked at Cdyn values of less than 50% of base line. At Cdyn of less than 15% of base line, VT' was 3.1-4.8 times the VT reference signal. No increase in total pulmonary resistance was noted, and Cdyn and VT/VT' returned to base line after histamine exposure was stopped. The authors conclude that gas compressibility effects become substantial during histamine-induced airway constriction in the guinea pig and that the VT/VT' ratio appears to provide a simple noninvasive method of detecting these changes.

  20. Synaptic localization of. kappa. opioid receptors in guinea pig neostriatum

    SciTech Connect

    Jomary, C.; Beaudet, A. ); Gairin, J.E. )

    1992-01-15

    Distribution of {kappa} opioid receptors was examined by EM radioautography in sections of guinea pig neostriatum with the selective {sup 125}I-labeled dynorphin analog (D-Pro{sup 10})dynorphin-(1-11). Most specifically labeled binding sites were found by probability circle analysis to be associated with neuronal membrane appositions. Because of limitations in resolution of the method, the radioactive sources could not be ascribed directly to either one of the apposed plasma membranes. Nevertheless, three lines of evidence favored a predominant association of ligand with dendrites of intrinsic striatal neurons: (1) the high frequency with which labeled interfaces implicated a dendrite, (2) the enrichment of dendrodendritic interfaces, and (3) the occurrence of dendritic profiles labeled at several contact points along their plasma membranes. A small proportion of labeled sites was associated with axo-axonic interfaces, which may subserve the {kappa} opioid-induced regulation of presynaptic dopamine and acetylcholine release documented in guinea pig neostriatum. These results support the hypothesis that in mammalian brain {kappa} opioid receptors are conformationally and functionally distinct from {mu} and {delta} types.

  1. Synaptic localization of kappa opioid receptors in guinea pig neostriatum.

    PubMed Central

    Jomary, C; Gairin, J E; Beaudet, A

    1992-01-01

    Distribution of kappa opioid receptors was examined by EM radioautography in sections of guinea pig neostriatum with the selective 125I-labeled dynorphin analog [D-Pro10]dynorphin-(1-11). Most specifically labeled binding sites were found by probability circle analysis to be associated with neuronal membrane appositions. Because of limitations in resolution of the method, the radioactive sources could not be ascribed directly to either one of the apposed plasma membranes. Nevertheless, three lines of evidence favored a predominant association of ligand with dendrites of intrinsic striatal neurons: (i) the high frequency with which labeled interfaces implicated a dendrite, (ii) the enrichment of dendro-dendritic interfaces, and (iii) the occurrence of dendritic profiles labeled at several contact points along their plasma membranes. A small proportion of labeled sites was associated with axo-axonic interfaces, which may subserve the kappa opioid-induced regulation of presynaptic dopamine and acetylcholine release documented in guinea pig neostriatum. Although most membrane-associated kappa sites were found at extrasynaptic locations, approximately 23% were associated with synaptic specializations. This proportion is markedly higher than that previously reported for either mu or delta sites in rat neostriatum. Whether labeled synapses represent preferential sites of action for kappa ligands remains to be established. In any event, these results support the hypothesis that in mammalian brain kappa opioid receptors are conformationally and functionally distinct from mu and delta types. Images PMID:1346233

  2. Spasmolytic effect of traditional herbal formulation on guinea pig ileum

    PubMed Central

    Kumar, Dushyant; Ganguly, Kuntal; Hegde, H. V.; Patil, P. A.; Kholkute, S. D.

    2015-01-01

    Background: The herbal formulation consisting of Andrographis paniculata Nees., Cassia fistula L., Foeniculum vulgare Mill. and Cuminum cyminum L. is widely used by the local traditional practitioners in rural Northern Karnataka for spasmodic abdominal pain. Objective: The present study was undertaken to evaluate safety and spasmolytic effect of poly-herbal formulation. Materials and Methods: Acute toxicity studies were carried out in Swiss mice, as per the Organization for Economic Co-operation and Development (OECD) guidelines. The spasmolytic activity of the formulation was studied in isolated guinea pig ileum model using histamine and acetylcholine as agonists. The data were analyzed by one-way ANOVA, followed by Dunnetts post-hoc test and P ≤ 0.05 was considered as significant. Results: The formulation did not show any adverse toxic effects and found to be safe. It also showed significant (P < 0.05) relaxation in different agonist like histamine and acetylcholine-induced contractions in guinea pig ileum. Conclusion: Antispasmodic activity of the herbal formulation can be attributed to its atropine-like activity. The present findings, therefore, support its utility in spasmodic abdominal pain. PMID:26604555

  3. Synaptic localization of kappa opioid receptors in guinea pig neostriatum.

    PubMed

    Jomary, C; Gairin, J E; Beaudet, A

    1992-01-15

    Distribution of kappa opioid receptors was examined by EM radioautography in sections of guinea pig neostriatum with the selective 125I-labeled dynorphin analog [D-Pro10]dynorphin-(1-11). Most specifically labeled binding sites were found by probability circle analysis to be associated with neuronal membrane appositions. Because of limitations in resolution of the method, the radioactive sources could not be ascribed directly to either one of the apposed plasma membranes. Nevertheless, three lines of evidence favored a predominant association of ligand with dendrites of intrinsic striatal neurons: (i) the high frequency with which labeled interfaces implicated a dendrite, (ii) the enrichment of dendro-dendritic interfaces, and (iii) the occurrence of dendritic profiles labeled at several contact points along their plasma membranes. A small proportion of labeled sites was associated with axo-axonic interfaces, which may subserve the kappa opioid-induced regulation of presynaptic dopamine and acetylcholine release documented in guinea pig neostriatum. Although most membrane-associated kappa sites were found at extrasynaptic locations, approximately 23% were associated with synaptic specializations. This proportion is markedly higher than that previously reported for either mu or delta sites in rat neostriatum. Whether labeled synapses represent preferential sites of action for kappa ligands remains to be established. In any event, these results support the hypothesis that in mammalian brain kappa opioid receptors are conformationally and functionally distinct from mu and delta types.

  4. Enzymic synthesis of leukotriene B4 in guinea pig brain.

    PubMed

    Shimizu, T; Takusagawa, Y; Izumi, T; Ohishi, N; Seyama, Y

    1987-05-01

    Leukotriene B4 [5(S), 12(R)-dihydroxy-6, 14-cis-8,10-trans-eicosatetraenoic acid] was obtained from endogenous arachidonic acid when slices of the guinea pig brain cortex were incubated with the calcium ionophore A 23187. Enzymes involved in its synthesis, arachidonate 5-lipoxygenase [arachidonic acid to 5(S)-hydroperoxy-6-trans-8,11,14-cis-eicosatetraenoic acid and subsequently to leukotriene A4] and leukotriene A4 hydrolase (leukotriene A4 to B4), were present in the cytosol fraction. Arachidonate 5-lipoxygenase was Ca2+-dependent, and was stimulated by ATP and the microsomal membrane, as was noted for the enzyme from mast cells. The lipid hydroperoxides stimulated 5-lipoxygenase by four- to sixfold. The leukotriene A4 hydrolase activity was rich in brain, and the specific activity (0.4 nmol/min/mg of protein) was much the same as that of guinea pig leukocytes. High activities of these enzymes were detected in the olfactory bulb, pituitary gland, hypothalamus, and cerebral cortex. Since leukotriene B4 is enzymically synthesized in the brain, possible roles related to neuronal functions or dysfunctions deserve to be examined.

  5. ACTION OF DIPHTHERIA TOXIN IN THE GUINEA PIG

    PubMed Central

    Baseman, Joel B.; Pappenheimer, A. M.; Gill, D. M.; Harper, Annabel A.

    1970-01-01

    The blood clearance and distribution in the tissues of 125I after intravenous injection of small doses (1.5–5 MLD or 0.08–0.25 µg) of 125I-labeled diphtheria toxin has been followed in guinea pigs and rabbits and compared with the fate of equivalent amounts of injected 125I-labeled toxoid and bovine serum albumin. Toxoid disappeared most rapidly from the blood stream and label accumulated and was retained in liver, spleen, and especially in kidney. Both toxin and BSA behaved differently. Label was found widely distributed among all the organs except the nervous system and its rate of disappearance from the tissues paralleled its disappearance from the circulation. There was no evidence for any particular affinity of toxin for muscle tissue or for a "target" organ. Previous reports by others that toxin causes specific and selective impairment of protein synthesis in muscle tissue were not confirmed. On the contrary, both in guinea pigs and rabbits, a reduced rate of protein synthesis was observed in all tissues that had taken up the toxin label. In tissues removed from intoxicated animals of both species there was an associated reduction in aminoacyl transferase 2 content. It is concluded that the primary action of diphtheria toxin in the living animal is to effect the inactivation of aminoacyl transferase 2. The resulting inhibition in rate of protein synthesis leads to morphologic damage in all tissues reached by the toxin and ultimately to death of the animal. PMID:5511567

  6. Guinea pig model for evaluating the potential public health risk of swine and avian influenza viruses.

    PubMed

    Sun, Yipeng; Bi, Yuhai; Pu, Juan; Hu, Yanxin; Wang, Jingjing; Gao, Huijie; Liu, Linqing; Xu, Qi; Tan, Yuanyuan; Liu, Mengda; Guo, Xin; Yang, Hanchun; Liu, Jinhua

    2010-11-23

    The influenza viruses circulating in animals sporadically transmit to humans and pose pandemic threats. Animal models to evaluate the potential public health risk potential of these viruses are needed. We investigated the guinea pig as a mammalian model for the study of the replication and transmission characteristics of selected swine H1N1, H1N2, H3N2 and avian H9N2 influenza viruses, compared to those of pandemic (H1N1) 2009 and seasonal human H1N1, H3N2 influenza viruses. The swine and avian influenza viruses investigated were restricted to the respiratory system of guinea pigs and shed at high titers in nasal tracts without prior adaptation, similar to human strains. None of the swine and avian influenza viruses showed transmissibility among guinea pigs; in contrast, pandemic (H1N1) 2009 virus transmitted from infected guinea pigs to all animals and seasonal human influenza viruses could also horizontally transmit in guinea pigs. The analysis of the receptor distribution in the guinea pig respiratory tissues by lectin histochemistry indicated that both SAα2,3-Gal and SAα2,6-Gal receptors widely presented in the nasal tract and the trachea, while SAα2,3-Gal receptor was the main receptor in the lung. We propose that the guinea pig could serve as a useful mammalian model to evaluate the potential public health threat of swine and avian influenza viruses.

  7. Guinea Pig Model for Evaluating the Potential Public Health Risk of Swine and Avian Influenza Viruses

    PubMed Central

    Pu, Juan; Hu, Yanxin; Wang, Jingjing; Gao, Huijie; Liu, Linqing; Xu, Qi; Tan, Yuanyuan; Liu, Mengda; Guo, Xin; Yang, Hanchun; Liu, Jinhua

    2010-01-01

    Background The influenza viruses circulating in animals sporadically transmit to humans and pose pandemic threats. Animal models to evaluate the potential public health risk potential of these viruses are needed. Methodology/Principal Findings We investigated the guinea pig as a mammalian model for the study of the replication and transmission characteristics of selected swine H1N1, H1N2, H3N2 and avian H9N2 influenza viruses, compared to those of pandemic (H1N1) 2009 and seasonal human H1N1, H3N2 influenza viruses. The swine and avian influenza viruses investigated were restricted to the respiratory system of guinea pigs and shed at high titers in nasal tracts without prior adaptation, similar to human strains. None of the swine and avian influenza viruses showed transmissibility among guinea pigs; in contrast, pandemic (H1N1) 2009 virus transmitted from infected guinea pigs to all animals and seasonal human influenza viruses could also horizontally transmit in guinea pigs. The analysis of the receptor distribution in the guinea pig respiratory tissues by lectin histochemistry indicated that both SAα2,3-Gal and SAα2,6-Gal receptors widely presented in the nasal tract and the trachea, while SAα2,3-Gal receptor was the main receptor in the lung. Conclusions/Significance We propose that the guinea pig could serve as a useful mammalian model to evaluate the potential public health threat of swine and avian influenza viruses. PMID:21124850

  8. Prevalence of dermatophytes and other superficial fungal organisms in asymptomatic guinea pigs in Southern Italy.

    PubMed

    d'Ovidio, D; Grable, S L; Ferrara, M; Santoro, D

    2014-07-01

    Guinea pigs have been indicated as a potential source of zoophilic dermatophytes that cause human dermatomycosis. The purpose of this study was to evaluate the prevalence of dermatophytes as well as saprophytic fungi in asymptomatic pet guinea pigs in Southern Italy. Two-hundred pet guinea pigs were enrolled from both private veterinary clinics and pet shops in the Campania region, Italy, from August 2012 to September 2013. Samples were collected using the MacKenzie's toothbrush technique. The plates were incubated for four weeks at 25°C and identification of the fungal colonies was based on both macroscopic and microscopic characteristics. Two pathogenic dermatophytes were isolated in 9 (4·5%) of 200 guinea pigs; Epidermophyton species in 2 (1%) and Scopulariopsis species in 7 (3·5%). Saprophytic dermatophytes were isolated from 151 (75·5%) animals enrolled. No fungal growth was observed in 40 (20%) guinea pigs. The results of this study indicate a low prevalence of pathogenic dermatophytes in pet guinea pigs in Southern Italy but the presence of Epidermophyton and Scopulariopsis species in asymptomatic pet guinea pigs. © 2014 British Small Animal Veterinary Association.

  9. Detection of antibodies against Theiler's murine encephalomyelitis virus GDVII strain in experimental guinea pigs.

    PubMed

    Häger, C; Glage, S; Held, N; Bleich, E M; Burghard, A; Mähler, M; Bleich, André

    2016-10-01

    A disease affecting guinea pigs called 'guinea pig lameness' characterized by clinical signs of depression, lameness of limbs, flaccid paralysis, weight loss and death within a few weeks was first described by Römer in 1911. After a research group in our facility kept laboratory guinea pigs from two different origins together in one room, lameness was observed in two animals. Further investigations revealed a serological immune response against Theiler's murine encephalomyelitis virus (TMEV; GDVII strain) in these animals. Histopathology of the lumbar spinal cord of these animals showed mononuclear cell infiltration and necrotic neurons in the anterior horn. Therefore, all guinea pigs from this contaminated animal unit, from other units in our facility, as well as from different European institutions and breeding centres were screened for antibodies directed against GDVII. Our investigations showed that approximately 80% of all guinea pigs from the contaminated animal unit were seropositive for GDVII, whereas animals from other separate units were completely negative. In addition, 43% of tested sera from the different European institutions and breeding centres contained antibodies against GDVII. The present data confirm that an unknown viral infection causes an immune response in experimental guinea pigs leading to seroconversion against GDVII and that guinea pigs from a commercial breeder are the source of the infection. © The Author(s) 2015.

  10. Clinical signs, therapy and zoonotic risk of pet guinea pigs with dermatophytosis.

    PubMed

    Kraemer, A; Hein, J; Heusinger, A; Mueller, R S

    2013-03-01

    Systematic studies about pet guinea pigs with dermatophytosis are rare. The aim of this study was to evaluate clinical signs, therapy and zoonotic risk of pet guinea pigs with dermatophytosis. Questionnaires from both owners (n = 74) of pet guinea pigs with dermatophytosis and their veterinarians (n = 101) were analysed regarding clinical signs, therapy and data pertinent to zoonotic potential. Trichophyton (T.) mentagrophytes was found in 97% of cases. In the weeks preceding the onset of the clinical signs, a new guinea pig joined the household in 43% of cases. One third of the affected guinea pigs had lived in the household for less than 3 months. Predominant clinical signs were alopecia (83%), scaling (73%) and crusting (70%). The most commonly affected body site was the head (75%). In approximately one quarter of the cases humans showed clinical signs of dermatophytosis, in half the households, only children were affected. Skin lesions were seen most often on the face, the neck and the arms. Pet guinea pigs carrying dermatophytes must be considered a serious zoonotic risk for their owners, especially for children. A major risk factor for dermatophytosis seems to be a recent acquisition of a new guinea pig.

  11. Pathogenesis of a Chinese strain of bovine adenovirus type 3 infection in albino guinea pigs.

    PubMed

    Shi, Hong-Fei; Zhu, Yuan-Mao; Yan, Hao; Ma, Lei; Wang, Xue-Zhi; Xue, Fei

    2014-12-01

    Bovine adenovirus type 3 (BAV-3) is considered one of the most important respiratory tract agents of cattle and is widespread among cattle around the world. A BAV-3 strain was isolated from a bovine nasal swab for the first time in China in 2009 and named HLJ0955. Subsequently, BAV-3 has frequently been isolated from calves with respiratory diseases in China. To date, only limited study on the pathogenesis of BAV-3 infection in cotton rats has been conducted, and the pathogenesis of BAV-3 infection in guinea pigs has not been reported. Therefore, sixteen albino guinea pigs were inoculated intranasally with HLJ0955. All of the infected guinea pigs had apparently elevated rectal temperatures (39.2 °C-39.9 °C) at 2-7 days post-inoculation (PI). Consolidation and petechial hemorrhage were also observed in guinea pigs experimentally infected with HLJ0955. Viral replication was detectable by virus isolation and titration and by immunohistochemistry in the lungs of guinea pigs as early as 24 h PI. Viral DNA was detectable in the lungs of infected guinea pigs during 11 days of observation by real-time PCR. Virus-neutralizing antibodies against BAV-3 were detectable from 11 days PI and reached a peak titer at 15 days PI. Histopathological changes mainly occurred in the lungs of infected guinea pigs and were characterized by thickening of alveolar septa, mononuclear cell infiltration, hemorrhage and alveolar epithelial necrosis. These results indicate that HLJ0955 can replicate in the lungs of guinea pigs and cause fever and gross and histological lesions. The guinea pig infection model of BAV-3 would serve as a useful system for monitoring the infection process and pathogenesis of the Chinese BAV-3 strain HLJ0955, as well as immune responses to BAV-3 vaccines.

  12. Natural infection of guinea pigs exposed to patients with highly drug-resistant tuberculosis

    PubMed Central

    Dharmadhikari, Ashwin S.; Basaraba, Randall J.; Van Der Walt, Martie L.; Weyer, Karin; Mphahlele, Matsie; Venter, Kobus; Jensen, Paul A.; First, Melvin W.; Parsons, Sydney; McMurray, David N.; Orme, Ian M.; Nardell, Edward A.

    2012-01-01

    A natural TB infection model using guinea pigs may provide useful information for investigating differences in transmission efficiency and establishment of active disease by clinical TB strains in a highly susceptible host under controlled environmental conditions. We sought to examine the capacity of naturally transmitted multidrug-resistant M. tuberculosis to establish infection and produce active disease in guinea pigs. Guinea pigs were continuously exposed for 4 months to the exhaust air of a 6-bed multidrug-resistant tuberculosis inpatient hospital ward in South Africa. Serial tuberculin skin test reactions were measured to determine infection. All animals were subsequently evaluated for histologic disease progression at necropsy. Although 75% of the 362 exposed guinea pigs had positive skin test reactions [≥6mm], only 12% had histopathologic evidence of active disease. Reversions (≥ 6 mm change) in skin test reactivity were seen in 22% of animals, exclusively among those with reactions of 6 to 13 mm. Only two of 86 guinea pigs with reversion had histological evidence of disease compared to 47% (31/66) of guinea pigs with large, non-reverting reactions. Immunosuppression of half the guinea pigs across all skin test categories did not significantly accelerate disease progression. In guinea pigs that reverted a skin test, a second positive reaction in 27 (33%) of them strongly suggested re-infection due to ongoing exposure. These results show that a large majority of guinea pigs naturally exposed to human-source strains of multidrug-resistant tuberculosis became infected, but that many resolved their infection and a large majority failed to progress to detectable disease. PMID:21478054

  13. Cysteinyl leucotriene receptor type 1 mediates contraction in human and guinea-pig oesophagus.

    PubMed

    Chang, B-S; Chang, J-C; Wang, Y-S; Huang, S-C

    2008-10-01

    Leucotriene D(4) (LTD(4)) causes contraction of the guinea-pig and cat oesophagus. Effects of cysteinyl leucotrienes in the human oesophagus were unknown. To investigate and compare the cysteinyl leucotriene effects in the human oesophagus with those in the guinea-pig oesophagus, we measured contraction of muscularis mucosae strips isolated from the human and guinea-pig oesophagus caused by cysteinyl leucotrienes, LTC(4), LTD(4) and LTE(4), as well as the dihydroxy leucotriene, LTB(4). Effects of leucotrienes in human were similar to those in guinea-pig oesophagus. LTC(4) and LTD(4) caused moderate, whereas LTE(4) caused mild, concentration-dependent contraction. LTE(4) was a partial agonist. In contrast, LTB(4) did not cause any contraction. The relative potencies for cysteinyl leucotrienes to cause contraction were LTD(4) = LTC(4) > LTE(4). The LTD(4)-induced contraction was moderately inhibited by two selective CysLT(1) receptor antagonists, montelukast and zafirlukast, in both human and guinea-pig oesophagus. In addition, the LTD(4)-induced contraction was not and only slightly inhibited by BAY u9773, the CysLT(1) and CysLT(2) receptor antagonist, in the human and guinea-pig oesophageal muscularis mucosae respectively. These indicate the existence of the CysLT(1) mediating oesophageal contraction in both human and guinea-pig oesophagus. The LTD(4)-induced contraction was not affected by tetrodotoxin, atropine or capsaicin, suggesting a direct effect. These results demonstrate that cysteinyl leucotrienes but not the dihydroxy leucotriene cause contraction in the human and guinea-pig oesophagus. CysLT(1) mediates contraction in both human and guinea-pig oesophagus.

  14. Fate and Distribution of 3H-Labeled T-2 Mycotoxin in Guinea Pigs

    DTIC Science & Technology

    1984-08-03

    Interim Mycotoxin in Guinea Pigs 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(a) B. CONTRACT OR GRANT NUMBER(-) J. G. Pace2, M. R. Watts, E. P. Burrows...on ,eveeae -Ide If necessary and Identify by block number) ś-2 mycotoxin , distribution, metabolism, guinea pigs, TLC ri 9ST-PAc’r rccit ue. a re! s...Ttl4e: F08te 2n4 s,, , ,H-T-2 t07in 84 08 24 077 zate anc Distribution of 3 H-Labeled T-2 Mycotoxin in Guinea Pigs. Face. J. G.. Watts, M. R

  15. Immunogenicity of heterologous Fc and Fab immunoglobulin fragments in rabbits, guinea-pigs and rats

    PubMed Central

    Binaghi, R. A.; Oriol, R.; Boussac-Aron, Yolande

    1967-01-01

    Rabbits, guinea-pigs and rats were immunized with various heterologous 7S and 19S immunoglobulins from each other and man, and the antisera obtained were studied by immunoelectrophoresis. Rabbits produced antibodies against the Fc and the Fab fragments of the immunoglobulin injected, while guinea-pigs and rats only produced anti-Fc antibodies. The fact that guinea-pigs and rats only respond to the specific determinants of each class of immunoglobulin provides a simple method for the preparation of class-specific antisera. ImagesFIG. 1FIG. 2 PMID:6027784

  16. Expression of Endogenous Retroviral Genes in Leukemic Guinea Pig Cells

    PubMed Central

    Davis, A. R.; Nayak, D. P.

    1977-01-01

    The expression of guinea pig retrovirus (5-bromodeoxyuridine[BUdR]-induced GPV) was studied in guinea pig L2C leukemic lymphoblasts by use of molecular hybridization of viral complementary DNA (cDNA) to cellular RNA. It was found that L2C leukemic lymphoblasts, leukemic spleen, and BUdR-induced virus-producing cells contain virus-specific RNA: 0.05% (800 to 960 copies per cell), 0.02% (360 copies per cell), and 0.3% (5,120 copies per cell), respectively. Adult normal liver and spleen, on the other hand, contain less than 0.2 copy of viral RNA per cell. Both BUdR-induced cells and L2C leukemic lymphoblasts contained 14S, 22S, 35S, and 70S RNA species of total and cytoplasmic virus-specific RNA as determined by sucrose velocity gradient analysis and hybridization of sucrose gradient fractions to cDNA. Virus-specific mRNA was identified in both BUdR-induced cells and L2C leukemic lymphoblasts by the criterion that it cosedimented with purified polyribosomes in a sucrose gradient and that it changed to a lower sedimentation value if polyribosomes were disaggregated with EDTA prior to centrifugation. Virus-specific mRNA obtained from either the polyribosome region of purified polyribosomes or the released messenger region of EDTA-disaggregated purified polyribosomes consisted of 14S, 20S, and 35S species in both BUdR-induced cells and L2C leukemic lymphoblasts. Hybridization of cDNA to the RNA of L2C leukemic lymphoblasts and BUdR-induced cells was essentially complete. Additionally, leukemic lymphoblast RNA could displace 95% of the hybridization of BUdR-induced GPV 70S RNA to guinea pig DNA. The midpoints of thermal denaturation of hybrids formed between GPV cDNA and the RNA of either L2C leukemic lymphoblasts or the 70S RNA of BUdR-induced GPV were both 89°C in 2× concentrated 0.15 M NaCl plus 0.015 M sodium citrate. These results show that BUdR-induced GPV genes are essentially completely expressed in L2C leukemic lymphoblasts and that virus-specific mRNA is

  17. Leukotriene B4 receptors on guinea pig alveolar eosinophils

    SciTech Connect

    Maghni, K.; de Brum-Fernandes, A.J.; Foeldes-Filep, E.G.; Gaudry, M.; Borgeat, P.; Sirois, P. )

    1991-09-01

    The existence of receptors for LTB4 on highly purified guinea pig alveolar eosinophils was investigated. Massive infiltration of eosinophils in alveolar spaces was induced in guinea pigs by i.v. injections of Sephadex beads G50 (16 mg/kg). Alveolar eosinophils (50 {times} 10(6) cells) were purified to approximately 98% by Percoll continuous density gradient centrifugation. The binding studies indicated that alveolar eosinophils bind LTB4 in a saturable, reversible and specific manner. Scatchard analysis indicated the existence of high-affinity binding sites (Kd1 = 1.00 {plus minus} 0.22 nM; Bmax1 = 966 {plus minus} 266 sites/cell) and low-affinity binding sites (Kd2 = 62.5 {plus minus} 8.9 nM; Bmax2 = 5557 {plus minus} 757 sites/cell). The metabolism of LTB4 by alveolar eosinophils in binding conditions was assessed by RP-HPLC and no significant degradation of (3H)LTB4 was observed. LTB4 dose-dependently stimulated eosinophil migration in both chemokinesis and chemotaxis assays with an EC50 value of 1.30 {plus minus} 0.14 and 18.14 {plus minus} 1.57 nM, respectively. LTB4 caused a dose-dependent increase in the production of superoxide anion with an apparent EC50 value of 50 {times} 10(-9) M in the authors experimental conditions. LTB4 also induced a dose-dependent increase in the generation of TxA2 with an EC50 value of 46.2 {times} 10(-9) M. Taken together, their results demonstrated that guinea pig alveolar eosinophils express two classes of specific receptors for LTB4. The high-affinity binding sites seem associated to chemokinesis and chemotaxis whereas the low-affinity binding sites seem associated to superoxide anion production and generation of TxA2. The existence of LTB4 receptors in eosinophils could explain the presence of these cells in hypersensitivity reactions.

  18. Ontogeny of fetal movements in the guinea pig.

    PubMed

    van Kan, C M; de Vries, J I P; Lüchinger, A B; Mulder, E J H; Taverne, M A M

    2009-09-07

    Assessment of fetal motility is an approach to evaluate the development and function of the nervous system before birth. Reference values for the time of first occurrence and the incidence of normal fetal movements are indispensable for studies in which prenatal motor activity is applied as a model to study the central and peripheral nervous systems. Studies on fetal motility have been performed in a few species, particularly in the human. The aim of the present study is to describe the ontogeny of fetal motility in the guinea pig, a precocious polytocous species. After a pilot study to establish procedures for repeated ultasonographic scanning of guinea pigs, 10 domesticated animals were scanned (5.0 or 7.5 MHz convex transducer) at 2-4 day intervals between day 24 and 63 of gestation (term age 68 days). Per animal two selected fetuses were each scanned for 15 min. Images were stored on videotape and analyzed off-line for the first onset, presence and quality of fetal movement patterns, and quantity of sideway bendings, general movements, breathing movements and periods of fetal rest. Twenty-five different movement patterns could be characterized, 6 emerging at the onset of motor activity were performed only temporarily. The very first fetal movement was observed on day 24 gestational age, and subsequently most other movements developed during a period of only 5 days. Interfetal difference in onset of the frequently occurring sideway bendings, general movements, and front and hind limb movements was only 2 days. Sideway bendings and general movements co-existed during days 29 to 43. There were developmental trends in the course of pregnancy. Sideway bendings increased rapidly between 24 and 30 days and declined hereafter. General movements and fetal breathing increased during midpregnancy and declined towards parturition. Conversely, fetal rest was observed for approximately 60% of time at midgestation and a marked increase was found towards parturition. There

  19. Citicoline retards myopia progression following form deprivation in guinea pigs

    PubMed Central

    Liu, Shuangzhen; Fu, Chunyan

    2016-01-01

    The retinal dopaminergic system is involved in the myopic shift following form deprivation. Citicoline has been demonstrated to stimulate the dopaminergic system in the brain and retina. Furthermore, citicoline has been used in many neurogenic diseases, such as senile cognitive impairment, stroke and Parkinson's disease as well as in amblyopia and glaucoma. Our aim was to investigate the effect of citicoline on the refractive state and retinal dopamine level in form deprivation myopia of guinea pigs. Guinea pigs, at an age of four weeks, were randomly divided into normal control, deprivation, deprived + citicoline and deprived + vehicle groups. Form deprivation myopia was induced by a translucent eye shield covering the right eye. Citicoline was injected intraperitoneally twice a day (500 mg/kg, 9 am and 9 pm) for 10 days. In vitro, retinal explants were cultured with citicoline for 24 h, with a final citicoline concentration of 100 µmol/L. The ocular refractive parameters and retinal dopamine content were measured. After occlusion for 10 days, the form-deprived eyes became myopic with an increase in axial length and a decrease in retinal dopamine content. The intraperitoneal injection of citicoline reduced the myopic degree (from −3.25 ± 0.77D to −0.62 ± 0.47D, P < 0.001) and partially raised retinal dopamine levels (from 0.55 ± 0.21 ng to 0.81 ± 0.24 ng, P < 0.01) in the form-deprived eyes. After 24 h of culturing retinal explants with citicoline, retinal dopamine content increased significantly (from 0.42 ± 0.14 ng to 0.62 ± 0.21 ng, P < 0.05). These results demonstrated that an intraperitoneal injection of citicoline could retard the myopic shift induced by form deprivation in guinea pigs, which was mediated by an increase in the retinal dopamine levels. PMID:26979720

  20. Transplantation and survival of mouse inner ear progenitor/stem cells in the organ of Corti after cochleostomy of hearing-impaired guinea pigs: preliminary results

    PubMed Central

    Barboza, L.C.M.; Lezirovitz, K.; Zanatta, D.B.; Strauss, B.E.; Mingroni-Netto, R.C.; Oiticica, J.; Haddad, L.A.; Bento, R.F.

    2016-01-01

    In mammals, damage to sensory receptor cells (hair cells) of the inner ear results in permanent sensorineural hearing loss. Here, we investigated whether postnatal mouse inner ear progenitor/stem cells (mIESCs) are viable after transplantation into the basal turns of neomycin-injured guinea pig cochleas. We also examined the effects of mIESC transplantation on auditory functions. Eight adult female Cavia porcellus guinea pigs (250-350g) were deafened by intratympanic neomycin delivery. After 7 days, the animals were randomly divided in two groups. The study group (n=4) received transplantation of LacZ-positive mIESCs in culture medium into the scala tympani. The control group (n=4) received culture medium only. At 2 weeks after transplantation, functional analyses were performed by auditory brainstem response measurement, and the animals were sacrificed. The presence of mIESCs was evaluated by immunohistochemistry of sections of the cochlea from the study group. Non-parametric tests were used for statistical analysis of the data. Intratympanic neomycin delivery damaged hair cells and increased auditory thresholds prior to cell transplantation. There were no significant differences between auditory brainstem thresholds before and after transplantation in individual guinea pigs. Some mIESCs were observed in all scalae of the basal turns of the injured cochleas, and a proportion of these cells expressed the hair cell marker myosin VIIa. Some transplanted mIESCs engrafted in the cochlear basilar membrane. Our study demonstrates that transplanted cells survived and engrafted in the organ of Corti after cochleostomy. PMID:27007652

  1. Antispasmodic effect of hydroalcoholic extract of Thymus vulgaris on the guinea-pig ileum.

    PubMed

    Babaei, Mehdi; Abarghoei, Mitra Emmami; Ansari, Reza; Vafaei, Abbas Ali; Taherian, Abbas Ali; Akhavan, Maziar Mohammad; Toussy, Gafar; Mousavi, Shahrokh

    2008-01-01

    The effects of Thymus vulgaris hydroalcoholic extract on the contractile responses of the isolated guinea-pig ileum were investigated. Contraction changes in the terminal ileum of guinea pigs were monitored using a force displacement transducer amplifier connected to a physiograph. Thymus vulgaris extract inhibited the contractile responses in a dose-dependent manner and also decreased the amplitude of peristaltic waves. It is concluded that T. vulgaris has an antispasmodic action on guinea pig ileum by decreasing the amplitudes of the muscle contractions during peristalsis. The EC50 was calculated as 1.7 mg mL(-1). In guinea-pig ileum the extract led to an antispasmodic effect, possibly by affecting the anticholinergic and serotoninergic pathways.

  2. Pathogenesis of XJ and Romero strains of Junin virus in two strains of guinea pigs.

    PubMed

    Yun, Nadezhda E; Linde, Nathaniel S; Dziuba, Natallia; Zacks, Michele A; Smith, Jeanon N; Smith, Jennifer K; Aronson, Judy F; Chumakova, Olga V; Lander, Heather M; Peters, Clarence J; Paessler, Slobodan

    2008-08-01

    Argentine hemorrhagic fever (AHF), a systemic infectious disease caused by infection with Junin virus, affects several organs, and patients can show hematologic, cardiovascular, renal, or neurologic symptoms. We compared the virulence of two Junin virus strains in inbred and outbred guinea pigs with the aim of characterizing this animal model better for future vaccine/antiviral efficacy studies. Our data indicate that this passage of the XJ strain is attenuated in guinea pigs. In contrast, the Romero strain is highly virulent in Strain 13 as well as in Hartley guinea pigs, resulting in systemic infection, thrombocytopenia, elevated aspartate aminotransferase levels, and ultimately, uniformly lethal disease. We detected viral antigen in formalin-fixed, paraffin-embedded tissues. Thus, both guinea pig strains are useful animal models for lethal Junin virus (Romero strain) infection and potentially can be used for preclinical trials in vaccine or antiviral drug development.

  3. Oxidative and glycolytic metabolism of semen components by washed guinea pig spermatozoa.

    PubMed

    Frenkel, G; Peterson, R N; Freund, M

    1975-02-01

    The concentration of several potentially metabolizable substances in guinea pig semen and the ability of these substances to support ATP synthesis and the motility of guinea pig sperm have been determined. Both glucose and fructose were present in high concentration in semen and were equipotent at the concentration tested in maintaining high levels of ATP and a high rate of motility. Lactic and pyruvic acids also supported a high rate of sperm motility but maintained lower levels of ATP. These constituents of guinea pig semen, as well as the metabolites alpha-glycerophosphate, succinic acid, and beta-hydroxybutyric acid, are oxidized at unusually high rates. The active oxidative metabolism of guinea pig sperm is compared with that of human sperm which is primarily glycolytic.

  4. The effect of restraining on the heart rate in guinea pigs

    NASA Technical Reports Server (NTRS)

    Mikiskova, H.

    1980-01-01

    The emotional effect of different applications of electrodes and the fixation for cariographic examination was investigated using guinea pigs. The effect of the stress is discussed in terms of heart rhythm and behavior.

  5. Papular dermatitis induced in guinea pigs by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae)

    USDA-ARS?s Scientific Manuscript database

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and ...

  6. Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs.

    PubMed

    Li, Jun-rong; Wang, Wei; Shi, Fang-xiong

    2015-12-01

    The effects of equine chorionic gonadotropin (eCG) on follicular development and ovulation in cyclic guinea pigs were investigated by histological and immunohistochemical analyses. Three groups of guinea pigs (n=12) were administrated subcutaneously with saline, 20 or 50 IU of eCG, respectively, on cyclic Day 12 (Day 1=vaginal openings). Ovaries were collected at 4 and 8 d after administration (6 animals per group each time). The eCG administration induced significant and distinct morphological changes in the ovaries, as it promoted the luteinization of granulosa cells, but not follicular development. In addition, proliferating cell nuclear antigen (PCNA) and steroidogenic acute regulatory protein (StAR) were immunolocalized specifically in luteinized follicles. Our experiments together indicate that eCG administration can induce follicular luteinization but not superovulation in guinea pigs. The eCG in cyclic guinea pigs functions similar to that of luteinizing hormone (LH), but not follicle-stimulating hormone (FSH).

  7. Pathogenesis of XJ and Romero Strains of Junin Virus in Two Strains of Guinea Pigs

    PubMed Central

    Yun, Nadezhda E.; Linde, Nathaniel S.; Dziuba, Natallia; Zacks, Michele A.; Smith, Jeanon N.; Smith, Jennifer K.; Aronson, Judy F.; Chumakova, Olga V.; Lander, Heather M.; Peters, Clarence J.; Paessler, Slobodan

    2008-01-01

    Argentine hemorrhagic fever (AHF), a systemic infectious disease caused by infection with Junin virus, affects several organs, and patients can show hematologic, cardiovascular, renal, or neurologic symptoms. We compared the virulence of two Junin virus strains in inbred and outbred guinea pigs with the aim of characterizing this animal model better for future vaccine/antiviral efficacy studies. Our data indicate that this passage of the XJ strain is attenuated in guinea pigs. In contrast, the Romero strain is highly virulent in Strain 13 as well as in Hartley guinea pigs, resulting in systemic infection, thrombocytopenia, elevated apartate aminotransferase levels, and ultimately, uniformly lethal disease. We detected viral antigen in formalin-fixed, paraffin-embedded tissues. Thus, both guinea pig strains are useful animal models for lethal Junin virus (Romero strain) infection and potentially can be used for preclinical trials in vaccine or antiviral drug development. PMID:18689636

  8. Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs*

    PubMed Central

    Li, Jun-rong; Wang, Wei; Shi, Fang-xiong

    2015-01-01

    The effects of equine chorionic gonadotropin (eCG) on follicular development and ovulation in cyclic guinea pigs were investigated by histological and immunohistochemical analyses. Three groups of guinea pigs (n=12) were administrated subcutaneously with saline, 20 or 50 IU of eCG, respectively, on cyclic Day 12 (Day 1=vaginal openings). Ovaries were collected at 4 and 8 d after administration (6 animals per group each time). The eCG administration induced significant and distinct morphological changes in the ovaries, as it promoted the luteinization of granulosa cells, but not follicular development. In addition, proliferating cell nuclear antigen (PCNA) and steroidogenic acute regulatory protein (StAR) were immunolocalized specifically in luteinized follicles. Our experiments together indicate that eCG administration can induce follicular luteinization but not superovulation in guinea pigs. The eCG in cyclic guinea pigs functions similar to that of luteinizing hormone (LH), but not follicle-stimulating hormone (FSH). PMID:26642181

  9. [Postmortem distribution of tetrodotoxin in tissues and body fluids of guinea pigs].

    PubMed

    Liu, Wei; Da, Qing; Shen, Min

    2012-06-01

    To investigate the postmortem distribution of tetrodotoxin in tissues and body fluids of guinea pig, and to provide method and evidence for forensic identification and clinical diagnosis and treatment. Guinea pigs were intragastric administrated with 100, 50, 15 microg/kg tetrodotoxin, respectively. The poisoning symptoms were observed. The samples of heart, liver, spleen, lung, kidney, brain, stomach, intestines, bile, heart blood and urine were collected. The concentrations of tetrodotoxin in tissues and body fluids were measured with liquid chromatography-tandem mass spectrometry (LC-MS/MS). After administrated with tetrodotoxin, all guinea pigs came out poisoning signs including tachypnea, weary and dead finally. Tetrodotoxin concentrations in lung, stomach, intestines and urine were higher, followed by blood, heart and brain. The concentration in bile was the lowest. Postmortem distribution of tetrodotoxin in guinea pig is uneven. The concentration in the lung, stomach, intestines, urine and heart blood are higher, those tissues could be used for diagnosis of tetrodotoxin poisoning.

  10. Infrared neural stimulation: beam path in the guinea pig cochlea

    PubMed Central

    Moreno, Laura E; Rajguru, Suhrud M; Matic, Agnella Izzo; Yerram, Nitin; Robinson, Alan M; Hwang, Margaret; Stock, Stuart; Richter, Claus-Peter

    2011-01-01

    It has been demonstrated INS can be utilized to stimulate spiral ganglion cells in the cochlea. Although neural stimulation can be achieved without direct contact of the radiation source and the tissue, the presence of fluids or bone between the target structure and the radiation source may lead to absorption or scattering of the radiation, which may limit the efficacy of INS. The present study demonstrates the neural structures in the radiation beam path that can be stimulated. Histological reconstructions and microCT of guinea pig cochleae stimulated with an infrared laser suggest that the orientation of the beam from the optical fiber determined the site of stimulation in the cochlea. Best frequencies of the INS-evoked neural responses obtained from the central nucleus of the inferior colliculus matched the histological sites in the spiral ganglion. PMID:21763410

  11. Mycoplasma pneumoniae induces cytotoxic activity in guinea pig bronchoalveolar cells

    SciTech Connect

    Kist, M.; Koester, H.; Bredt, W.

    1985-06-01

    Precultured guinea pig alveolar macrophages (AM) and freshly harvested alveolar cells (FHAC) activated by interaction with Mycoplasma pneumoniae were cytotoxic for xenogeneic /sup 75/selenomethionine-labeled tumor target cells. Phagocytosis of whole opsonized or nonopsonized M. pneumoniae cells was more effective in eliciting cytotoxicity than uptake of sonicated microorganisms. The addition of living mycoplasma cells to the assay system enhanced the cytotoxic effect considerably. Target cells were significantly more susceptible to the cytotoxic action of phagocytes if they were coated with mycoplasma antigen or cocultured together with M. pneumoniae. The activation of the phagocytes could be inhibited by 2-deoxy-D-glucose but not by antimicrobial substances suppressing mycoplasma protein synthesis. It was accompanied by /sup 51/Cr release without detectable signs of cell damage. The supernatants of activated cells were cytotoxic for approximately 24 h. Inhibition, release, and cytotoxic activity indicate the necessity of an intact metabolism of the effector cells and suggest a secretion of cytotoxic substances.

  12. Middle ear overpressure treatment of endolymphatic hydrops in guinea pigs.

    PubMed

    Sakikawa, Y; Kimura, R S

    1997-01-01

    Guinea pigs placed outside or inside a pressure chamber and exposed to 49.2 cm H2O overpressure continuously for 24 h immediately after blockage of the endolymphatic duct showed no significant difference in the magnitude of endolymphatic hydrops when compared to controls, although there was a slight indication of a volume decrease in the outside-treatment group and an increase in the inside-treatment group. A pressure increase of 49.2 cm H2O in the external auditory canal for 1 h twice a day for 2 weeks outside the chamber significantly inhibited the development of hydrops. The latter result supports the merit of pressure application through the external auditory canal as a treatment for Meniere's disease.

  13. [Micro-CT imaging of guinea pig cochlear].

    PubMed

    Sun, Cheng-cheng; Jiang, Zi-dong; Zhang, Kai

    2012-12-25

    To employ micro-CT equipment for nondestructive three-dimensional (3D) imaging of internal ear. The guinea pigs were anesthetized by napental and bilateral cochleas harvested. Cochlea was fixed in glutaraldehyde before scanning of micro-CT. Two-dimensional (2D) images were acquired for a 3D model of reconstruction. The 2D images was distinct enough to visualize vestibular gallery, scala media, scala tympani, Reissner's membrane, velum, organ of Corti and spiral ganglion, etc. The 3D structure model was excellent for viewing and free to revolve in any axial direction. Micro-CT may allow nondestructive three-dimensional imaging of internal ear. As compared with the traditional method of morphology, this approach is able to save samples, easy to operate and has a high resolution. And it is more easily popularized than the synchrotron radiation approach.

  14. Transmission of influenza B viruses in the guinea pig.

    PubMed

    Pica, Natalie; Chou, Yi-Ying; Bouvier, Nicole M; Palese, Peter

    2012-04-01

    Epidemic influenza is typically caused by infection with viruses of the A and B types and can result in substantial morbidity and mortality during a given season. Here we demonstrate that influenza B viruses can replicate in the upper respiratory tract of the guinea pig and that viruses of the two main lineages can be transmitted with 100% efficiency between inoculated and naïve animals in both contact and noncontact models. Our results also indicate that, like in the case for influenza A virus, transmission of influenza B viruses is enhanced at colder temperatures, providing an explanation for the seasonality of influenza epidemics in temperate climates. We therefore present, for the first time, a small animal model with which to study the underlying mechanisms of influenza B virus transmission.

  15. Experimental infection with Treponema hyodysenteriae in guinea pigs.

    PubMed Central

    Joens, L A; Songer, J G; Harris, D L; Glock, R D

    1978-01-01

    Outbred and inbred (Hartley strain) guinea pigs (GP) were inoculated intragastrically with pathogenic and nonpathogenic Treponema hyodysenteriae. GP 3 to 16 weeks old received T. hyodysenteriae after a fasting period of 36 to 72 h. Infected GP with pathogenic T. hyodysenteriae developed a diarrheal and/or depressive condition, with mucus but not blood in the feces. Of 88 GP, 40 had gross lesions resembling those of swine dysentery. Lesions were limited mainly to the large intestine. TP used as controls or inoculated with nonpathogenic T. hyodysenteriae did not develop these lesions in the large intestine. These studies suggest that the GP may be used as an animal model for swine dysentery. PMID:730345

  16. Investigation of Guinea Pig Performance on an Eight-Lane Treadmill

    DTIC Science & Technology

    1991-11-01

    exercise model . Training was conducted over a twelve- day period at speeds ranging from 0.08 mph (1.93 mpm) to 0.50 mph (11.61 mpin) and session lengths from...conditioning, similar requirements when testing pretreatmant and therapy compounds should reflect this conditioned state. The guinea pig model is...standard guinea pig exercise model is the swim test devised by Rylands [3). This test has proven unsatisfactory for two reasons: a fairly large number

  17. A Pilot Study of Uterine Artery Embolization with Tris-Acryl Gelatin Microspheres in Guinea Pigs

    SciTech Connect

    Zhuang Wenquan; Tan Guosheng; Guo Wenbo; Yang Jianyong

    2012-06-15

    Objective: This study was designed to establish guinea pigs as an animal model for uterine artery embolization (UAE) with tris-acryl gelatin microspheres (TAGM). Methods: Twenty-five female adult guinea pigs were randomly divided into two groups, including a uterine artery casting mould group (n = 10) and a UAE group (n = 15). Pelvic angiography and vascular casting mould were performed in the first group. The anatomical characters of the pelvic cavity in guinea pigs were described. In the second group, the technical feasibility of performing UAE with TAGM in guinea pigs was investigated. The histopathological slides of the uterus of guinea pigs after UAE were examined to inspect the outcomes of UAE. Results: The uterine artery springs from the internal iliac artery, ascends tortuously along the cervix, and gives off vertically 8-10 branches to the cervix uteri and uterine horns. The diameters of the trunk of the uterine artery and its first branch were 0.32 {+-} 0.027 mm and 0.14 {+-} 0.01 mm, respectively. For UAE animals, the dosages of 40-120 and 100-300 {mu}m TAGM were 0.033 {+-} 0.003 ml and 0.015 {+-} 0.002 ml, respectively. On histopathological slides, embosphere particles were found in the first branches of the uterine artery, the subserous arteries, and the intramural arteries. Inflammatory reactions in the uterus were common in guinea pigs after UAE. Local or dispersed areas of necrosis in uterus also were observed in a few guinea pigs. Conclusions: Guinea pigs are an appropriate and feasible model for UAE with TAGM.

  18. SB223412, a neurokinin-3 receptor-selective antagonist, suppresses testosterone secretion in male guinea pigs.

    PubMed

    Nakamura, Sho; Ito, Yoshiko; Yamamoto, Koki; Takahashi, Chudai; Dai, Mingdao; Tanahashi, Miyu; Uenoyama, Yoshihisa; Tsukamura, Hiroko; Oishi, Shinya; Maeda, Kei-Ichiro; Matsuda, Fuko

    2017-10-15

    Guinea pigs are important zoo animals and have been recommended for animal-assisted activities or therapy, however there are problems concerning testosterone inducing aggressive or sexual behaviors in male guinea pigs. Testicular testosterone secretion is regulated by pulsatile gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) release in mammals. The mechanism generating GnRH/LH pulses is thought to be governed by kisspeptin neurons, which coexpress neurokinin B (NKB) and dynorphin A (Dyn), in the arcuate nucleus (ARC). Kisspeptin neurons in the ARC are frequently referred to as KNDy neurons. The purpose of this study was to examine whether the antagonization of NKB-neurokinin-3 receptor (NK3R) signaling can manipulate testosterone secretion in male guinea pigs. A single subcutaneous administration or 7 days of oral administration of an NK3R-selective antagonist, SB223412 (50 mg/body), significantly decreased plasma testosterone levels in male guinea pigs. In vitro binding assays confirmed that SB223412 has a high affinity to guinea pig NK3R. These results suggest that SB223412 could be used as an orally-available compound to suppress testosterone levels in male guinea pigs. Double labeling in situ hybridization of kisspeptin and either NKB or Dyn showed that kisspeptin-expressing neurons contained NKB (77.9%) or Dyn (62.3%) in the ARC, suggesting the presence of KNDy neurons in the ARC of guinea pigs. In conclusion, the present study shows that SB223412 could be a candidate compound to suppress testosterone secretion in male guinea pigs for controlling sexual and aggressive behaviors in the species. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Behavioral responses of deafened guinea pigs to intracochlear electrical stimulation: a new rapid psychophysical procedure.

    PubMed

    Agterberg, Martijn J H; Versnel, Huib

    2014-07-01

    In auditory research the guinea pig is often preferred above rats and mice because of the easily accessible cochlea and because the frequency range of its hearing is more comparable to that of humans. Studies of the guinea-pig auditory system primarily apply histological and electrophysiological measures. Behavioral animal paradigms, in particular in combination with these histological and electrophysiological methods, are necessary in the development of new therapeutic interventions. However, the guinea pig is not considered an attractive animal for behavioral experiments. Therefore, the purpose of this study was to develop a behavioral task suitable for guinea pigs, that can be utilized in cochlear-implant related research. Guinea pigs were trained in a modified shuttle-box in which a stream of air was used as unconditioned stimulus (UCS). A stream of air was preferred over conventionally used methods as electric foot-shocks since it produces less stress, which is a confounding factor in behavioral experiments. Hearing guinea pigs were trained to respond to acoustic stimuli. They responded correctly within only five sessions of ten minutes. The animals maintained their performance four weeks after the right cochlea was implanted with an electrode array. After systemic deafening, the animals responded in the first session immediately to intracochlear electrical stimulation. These responses were not affected by daily chronic electrical stimulation (CES). In conclusion, the present study demonstrates that guinea pigs can be trained relatively fast to respond to acoustic stimuli, and that the training has a lasting effect, which generalizes to intracochlear electrical stimulation after deafening. Furthermore, it demonstrates that bilaterally deafened guinea pigs with substantial (∼50%) loss of spiral ganglion cells (SGCs), detect intracochlear electrical stimulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Spontaneous behavior in noise and silence: a possible new measure to assess tinnitus in Guinea pigs.

    PubMed

    Heeringa, Amarins N; Agterberg, Martijn J H; van Dijk, Pim

    2014-01-01

    This study describes two experiments that were conducted in search for a behavioral paradigm to test for tinnitus in guinea pigs. Conditioning paradigms are available to determine the presence of tinnitus in animals and are based on the assumption that tinnitus impairs their ability to detect silent intervals in continuous noise. Guinea pigs have not been subjected to these paradigms yet; therefore, we investigated whether guinea pigs could be conditioned in the two-way shuttle-box paradigm to respond to silent intervals in noise. Even though guinea pigs could be trained relatively easy to respond to the presence of a noise interval, training guinea pigs to silent intervals in noise was unsuccessful. Instead, it appeared that they became immobile when the continuous stimulus was suddenly stopped. This was confirmed by the next experiment, in which we subjected guinea pigs to alternating intervals of noise and silence with a random duration between 30 and 120 s. Indeed, guinea pigs were significantly longer immobile during silence compared to during noise. By interpreting immobility as a signature of perceiving silence, we hypothesized that the presence of tinnitus would reduce immobility in silence. Therefore, we unilaterally exposed one group of guinea pigs to an 11-kHz tone of 124 dB sound pressure level for 1 h. A subset of the exposed animals was significantly more active in silence, but also more active in noise, as compared to the control group. The increased mobility during silent intervals might represent tinnitus. However, the increased mobility in noise of this group implies that the observed behavior could have derived from, e.g., an overall increase in activity. Therefore, conducting validation experiments is very important before implementing this method as a new screening tool for tinnitus. Follow-up experiments are discussed to further elucidate the origin of the increased mobility in both silence and noise.

  1. [Measurement of airway resistance and reactivity in guinea pigs using double-chamber plethysmography].

    PubMed

    Yao, Wei-min; Lai, Ke-fang; Luo, Yuan-ming; Liu, Chun-li; Chen, Ru-chong; Luo, Wei; Zhong, Nan-shan

    2009-05-01

    To establish a method for measurement of airway resistance (sRaw) and reactivity in guinea pigs. Methacholine spray at gradient concentrations was given to guinea pigs. PC100 was defined as the concentration of methacholine when the sRaw doubled in the guinea pigs using a double-chamber plethysmograph. The time for the recovery of PC100 resistance to baseline levels was measured. The sRaw and PC100 were measured twice on days 1 and 15 (4 time points) in the guinea pigs before and after OVA challenge. PC100 in a normal guinea pig airway was shown to recover the baseline level within 1 h. Double-chamber plethysmographical measurement of the sRaw and PC100 in normal guinea pigs did not show significant differences between the time points [sRaw: 3.25-/+0.67, 3.33-/+0.58, 3.30-/+0.56, and 3.32-/+0.75 cm H2O.s; log2PC100: 8.48-/+0.94, 8.64-/+1.04, 8.56-/+0.67, and 8.64-/+0.60, respectively, P>0.05]. The sRaw and airway reactivity were significantly increased in guinea pigs challenged with OVA [sRaw: 7.08-/+1.82 vs 2.87-/+0.53 cmH2O.s, P<0.01; log2PC100: 6.64-/+1.26 vs 8.48-/+1.17, P<0.01]. A double-chamber plethysmography for measurement of sRaw and airway reactivity in guinea pig is established successfully.

  2. Spontaneous Behavior in Noise and Silence: A Possible New Measure to Assess Tinnitus in Guinea Pigs

    PubMed Central

    Heeringa, Amarins N.; Agterberg, Martijn J. H.; van Dijk, Pim

    2014-01-01

    This study describes two experiments that were conducted in search for a behavioral paradigm to test for tinnitus in guinea pigs. Conditioning paradigms are available to determine the presence of tinnitus in animals and are based on the assumption that tinnitus impairs their ability to detect silent intervals in continuous noise. Guinea pigs have not been subjected to these paradigms yet; therefore, we investigated whether guinea pigs could be conditioned in the two-way shuttle-box paradigm to respond to silent intervals in noise. Even though guinea pigs could be trained relatively easy to respond to the presence of a noise interval, training guinea pigs to silent intervals in noise was unsuccessful. Instead, it appeared that they became immobile when the continuous stimulus was suddenly stopped. This was confirmed by the next experiment, in which we subjected guinea pigs to alternating intervals of noise and silence with a random duration between 30 and 120 s. Indeed, guinea pigs were significantly longer immobile during silence compared to during noise. By interpreting immobility as a signature of perceiving silence, we hypothesized that the presence of tinnitus would reduce immobility in silence. Therefore, we unilaterally exposed one group of guinea pigs to an 11-kHz tone of 124 dB sound pressure level for 1 h. A subset of the exposed animals was significantly more active in silence, but also more active in noise, as compared to the control group. The increased mobility during silent intervals might represent tinnitus. However, the increased mobility in noise of this group implies that the observed behavior could have derived from, e.g., an overall increase in activity. Therefore, conducting validation experiments is very important before implementing this method as a new screening tool for tinnitus. Follow-up experiments are discussed to further elucidate the origin of the increased mobility in both silence and noise. PMID:25360130

  3. Glutathione oxidation unmasks proarrhythmic vulnerability of chronically hyperglycemic guinea pigs

    PubMed Central

    Xie, Chaoqin; Biary, Nora; Tocchetti, Carlo G.; Aon, Miguel A.; Paolocci, Nazareno; Kauffman, Justin

    2013-01-01

    Chronic hyperglycemia in type-1 diabetes mellitus is associated with oxidative stress (OS) and sudden death. Mechanistic links remain unclear. We investigated changes in electrophysiological (EP) properties in a model of chronic hyperglycemia before and after challenge with OS by GSH oxidation and tested reversibility of EP remodeling by insulin. Guinea pigs survived for 1 mo following streptozotocin (STZ) or saline (sham) injection. A treatment group received daily insulin for 2 wk to reverse STZ-induced hyperglycemia (STZ + Ins). EP properties were measured using high-resolution optical action potential mapping before and after challenge of hearts with diamide. Despite elevation of glucose levels in STZ compared with sham-operated (P = 0.004) and STZ + Ins (P = 0.002) animals, average action potential duration (APD) and arrhythmia propensity were not altered at baseline. Diamide promoted early (<10 min) formation of arrhythmic triggers reflected by a higher arrhythmia scoring index in STZ (P = 0.045) and STZ + Ins (P = 0.033) hearts compared with sham-operated hearts. APD heterogeneity underwent a more pronounced increase in response to diamide in STZ and STZ + Ins hearts compared with sham-operated hearts. Within 30 min, diamide resulted in spontaneous incidence of ventricular tachycardia and ventricular fibrillation (VT/VF) in 3/6, 2/5, 1/5, and 0/4 STZ, STZ + Ins, sham-operated, and normal hearts, respectively. Hearts prone to VT/VF exhibited greater APD heterogeneity (P = 0.010) compared with their VT/VF-free counterparts. Finally, altered EP properties in STZ were not rescued by insulin. In conclusion, GSH oxidation enhances APD heterogeneity and increases arrhythmia scoring index in a guinea pig model of chronic hyperglycemia. Despite normalization of glycemic levels by insulin, these proarrhythmic properties are not reversed, suggesting the importance of targeting antioxidant defenses for arrhythmia suppression. PMID:23376824

  4. Differential release of guinea pig sperm acrosomal components during exocytosis.

    PubMed

    Kim, K S; Foster, J A; Gerton, G L

    2001-01-01

    The contents of the sperm acrosome are compartmentalized at the biochemical and morphological levels. Biochemically, the acrosome can be considered to be comprised of two compartments: one consisting of readily soluble proteins and one containing a particulate acrosomal matrix. To test the hypothesis that compartmentalization affects the release of acrosomal components during the course of secretion in guinea pig sperm, we examined the relationship between the presence of specific proteins and acrosomal status and monitored the recovery of acrosomal constituents in the medium surrounding sperm induced to undergo exocytosis with the ionophore A23187. Cysteine-rich secretory protein 2 (CRISP-2), a soluble component of the acrosome, was rapidly lost from the acrosome soon after ionophore treatment. However, acrosomal matrix components remained associated with the sperm for longer periods. AM67, a matrix component and the guinea pig orthologue of the mouse sperm zona pellucida-binding protein sp56, was released at a slower rate than was CRISP-2 but at a faster rate than were two other matrix proteins, AM50 and proacrosin. Coincident with their release from the sperm, AM50 and proacrosin were posttranslationally modified, probably by proteolysis. The release of proacrosin from the matrix appears associated with the conversion of this protein to the enzymatically active acrosin protease. These results provide strong support for the hypothesis that compartmentalization plays a significant role in regulating the release of proteins during the course of acrosomal exocytosis. Acrosomal matrix proteins remain associated with the sperm for prolonged periods of time following the induction of acrosomal exocytosis, suggesting that transitional acrosomal intermediates may have significant functions in the fertilization process.

  5. Transduction sites of vagal mechanoreceptors in the guinea pig esophagus.

    PubMed

    Zagorodnyuk, V P; Brookes, S J

    2000-08-15

    Extrinsic afferent neurons play an essential role in both sensation and reflex control of visceral organs, but their specialized morphological peripheral endings have never been functionally identified. Extracellular recordings were made from fine nerve trunks running between the vagus nerve and esophagus of the guinea pig. Mechanoreceptors, which responded to esophageal distension, fired spontaneously, had low thresholds to circumferential stretch, and were slowly adapting. Calibrated von Frey hairs (0.12 mN) were used to probe the serosal surface at 100-200 sites, which were mapped on a video image of the live preparation. Each stretch-sensitive unit had one to three highly localized receptive fields ("hot spots"), which were marked with Indian ink applied on the tip of the von Frey hair. Recorded nerve trunks were then filled anterogradely, using biotinamide in an artificial intracellular solution. Receptive fields were consistently associated with intraganglionic laminar endings (IGLEs) in myenteric ganglia, but not with other filled neuronal structures. The average distance of receptive fields to IGLEs was 73 +/- 14 microm (24 receptive fields, from 12 units; n = 5), compared to 374 +/- 17 microm for 240 randomly generated sites (n = 5; p < 0.001). After maintained probing on a single receptive field, spontaneous discharge of units was inhibited, as were responses to distension. During adapted discharge to maintained distension, interspike intervals were distributed in a narrow range. This indicates that multiple receptive fields interact to encode mechanical distortion in a graded manner. IGLEs are specialized transduction sites of mechanosensitive vagal afferent neurons in the guinea pig esophagus.

  6. Acute and subchronic dermal toxicity of nanosilver in guinea pig.

    PubMed

    Korani, M; Rezayat, S M; Gilani, K; Arbabi Bidgoli, S; Adeli, S

    2011-01-01

    Silver has been used as an antimicrobial agent for a long time in different forms, but silver nanoparticles (nanosilver) have recently been recognized as potent antimicrobial agents. Although nanosilver is finding diverse medical applications such as silver-based dressings and silver-coated medical devices, its dermal and systemic toxicity via dermal use has not yet been identified. In this study, we analyzed the potential toxicity of colloidal nanosilver in acute and subchronic guinea pigs. Before toxicity assessments, the size of colloidal nanosilver was recorded in sizes <100 nm by X-ray diffraction and transmission electron microscopy. For toxicological assessments, male guinea pigs weighing 350 to 400 g were exposed to two different concentrations of nanosilver (1000 and 10,000 μg/mL) in an acute study and three concentrations of nanosilver (100, 1000, and 10,000 μg/mL) in a subchronic study. Toxic responses were assessed by clinical and histopathologic parameters. In all experimental animals the sites of exposure were scored for any type of dermal toxicity and compared with negative control and positive control groups. In autopsy studies during the acute test, no significant changes in organ weight or major macroscopic changes were detected, but dose-dependent histopathologic abnormalities were seen in skin, liver, and spleen of all test groups. In addition, experimental animals subjected to subchronic tests showed greater tissue abnormalities than the subjects of acute tests. It seems that colloidal nanosilver has the potential to provide target organ toxicities in a dose- and time-dependent manner.

  7. Blast cells transfer experimental hypersensitivity pneumonitis in guinea pigs

    SciTech Connect

    Schuyler, M.; Cook, C.; Listrom, M.; Fengolio-Preiser, C.

    1988-06-01

    We previously demonstrated that experimental hypersensitivity pneumonitis (HP) can be transferred by lymph node cells (LNC) cultured in vitro with antigen. The purpose of this study was to identify the cells responsible for transfer and to determine if pulmonary cells can transfer HP. We cultured LNC from sensitized Strain 2 guinea pigs with a soluble extract of Micropolyspora faeni for 72 h, separated lymphoblasts from small lymphocytes, and transferred both subpopulations intravenously to syngeneic recipients. We also transferred irradiated lymphoblasts (1,500 rads), macrophage-depleted, lymphoblast-enriched populations, and pulmonary cells either without culture or after culture with M. faeni. Control animals received an equal volume of medium. All recipient animals were challenged intratracheally (i.t.) with M. faeni 48 h after the cell transfer, and they were killed 4 days after i.t. challenge. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. This measurement was reproducible (r = 0.95 for duplicate measurements, n = 55). All guinea pigs were maintained in HEPA-filtered air. There was a low level of pulmonary response to an i.t. challenge of M. faeni in animals that received medium. Animals that received pulmonary cells, either cultured or noncultured, did not differ from those in the control group. There was a substantial increase (p less than 0.01) in the extent of pulmonary abnormalities in the recipients of the lymphoblast population, with significant correlation (r = 0.87, p less than 0.01) between the number of lymphoblasts transferred and the extent of pulmonary abnormalities.

  8. Different roles of retinal dopamine in albino Guinea pig myopia.

    PubMed

    Mao, Junfeng; Liu, Shuangzhen

    2017-02-03

    To investigate whether the different role of ocular dopamine was involved in the myopic development between spontaneous myopia (SM) and form deprivation myopia (FDM) in albino guinea pigs. 55 myopic animals were randomly divided into SM, Levodapa (L-DOPA), L-DOPA+carbidopa and vehicle. 70 non-myopic animals were randomly divided into normal control, FDM, L-DOPA+FDM, L-DOPA+carbidopa+FDM and vehicle. Once per day, for 14days, L-DOPA (10mg/kg) was injected intraperitoneally, and carbidopa (1μg) was injected at the same time into the peribulbar space of the right eye. Refractive parameters and dopamine content in neural retina and RPE/choroid complex were measured. In SM animals, high myopia was formed at 5 week of ages. L-DOPA treatment could reduce its myopic degree, and inhibit the increase of axial length and vitreous chamber depth with the increase of retinal dopamine in both eyes. Administration of carbidopa could prevent the increase of retinal dopamine induced by L-DOPA, but no influenced on its refractive state in the injected eyes. In non-SM animals, intraperitoneal L-DOPA could inhibit FDM, accompanied by the increase of retinal dopamine. Carbidopa treatment diminished the inhibition of FDM and prevented the increase in retinal dopamine by L-Dopa. Retinal dopamine was highly correlated with ocular refraction in FDM, but not in SM. There was no significant difference in dopamine content of RPE/choroid complex among all groups. The role of retinal dopamine was different between SM and FDM in albino guinea pigs. Although systemic L-DOPA could inhibit the development of SM and FDM, retinal dopamine was only involved in the L-DOPA inhibition on FDM, but not on SM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Involvement of chymase in allergic conjunctivitis of guinea pigs.

    PubMed

    Nabe, Takeshi; Kijitani, Yurie; Kitagawa, Yuriko; Sakano, Emi; Ueno, Tomoko; Fujii, Masanori; Nakao, Shintaro; Sakai, Masaru; Takai, Shinji

    2013-08-01

    It has been reported that chymase activity was increased in allergic conjunctivitis patients and this activity was correlated with the severity of the disease. However, the precise roles of chymase in allergic conjunctivitis are unclear, and whether chymase inhibitors are effective for allergic conjunctivitis has not been reported even in experimental animal models. In this study, the roles of chymase in the pathogenesis were evaluated using a selective chymase inhibitor, ONO-WH-236, in a guinea pig model of allergic conjunctivitis induced by cedar pollen. Sensitized guinea pigs were challenged by the pollen, followed by assessing redness and edema in the conjuntiva, and counting the frequency of eye scratching as an itch-associated response. Treatment with the ONO-WH-236 (40 and 80 mg/kg, p.o.) dose-dependently inhibited the induction of redness, edema and scratching behavior. An anti-histaminic drug, ketotifen (3 mg/kg, p.o.), also significantly inhibited conjunctivitis symptoms. Chymase activity was increased in ophthalmic lavage fluid immediately after the pollen challenge. The increase in chymase activity was inhibited by in vivo treatment with ONO-WH-236. Interestingly, increased histamine in the ophthalmic lavage fluid immediately after the challenge was also inhibited by the chymase inhibitor. Administration of human recombinant chymase by eye dropping (0.09 and 0.9 μg/eye) dose-dependently induced scratching behavior, which was inhibited by not only ONO-WH-236 but also ketotifen; however, chymase administration induced only weak redness in the conjunctiva, which was resistant to treatment with anti-histaminic drugs. In conclusion, it was suggested that chymase was released from mast cells after antigen challenge, followed by the induction of conjunctivitis symptoms through histamine release from mast cells. Thus, chymase could be a potential target for pharmacotherapy for allergic conjunctivitis.

  10. Ototoxicity of acetic acid on the guinea pig cochlea.

    PubMed

    Yamano, Takafumi; Higuchi, Hitomi; Nakagawa, Takashi; Morizono, Tetsuo

    2015-12-14

    To evaluate the ototoxicity of acetic acid solutions. Compound action potentials (CAPs) of the eighth nerve were measured in guinea pigs before and after the application of acetic acid in the middle ear cavity. The pH values of the acetic acid solutions were pH 3.0, 4.0, and 5.0, and the application times were 30 min, 24 h, and 1 week. Acetic acid solution (pH 3.0, N = 3) for 30 min caused no significant elevation in CAP threshold at 4 kHz, but a significant elevation in the threshold was noted for 8 kHz and clicks. Acetic acid solutions (pH 4.0 N = 6, 5.0 N = 5) for 30 min caused no significant elevation in CAP. Acetic acid solution (pH 4.0) for 24 h (N = 5) caused significant elevations of the CAP threshold for 8 kHz, 4 kHz, and for clicks. Acetic acid (pH 5.0) for 24 h (N = 3) caused a significant elevation of the CAP threshold for 4 kHz, but not for 8 kHz or clicks. Acetic acid (pH 5.0) for 1 week (N = 3) caused a small but significant elevation CAP the threshold for 8 kHz and 4 kHz tone bursts, but no significant change was noted for clicks. We found a significant toxic effect of acetic acid in guinea pigs on eighth-nerve compound action potentials when the pH was 5.0 or lower. Clearly, the stronger the acidity, and longer the exposure time, the more the CAP threshold was elevated.

  11. Methadone-induced respiratory depression in the neonatal guinea pig.

    PubMed

    Nettleton, Rosemary T; Ransom, Ty A; Abraham, Stephanie L; Nelson, Cole S; Olsen, George D

    2007-12-01

    Respiratory depression, the most serious side-effect of opioid treatment, is well documented for morphine, the most commonly used opioid in neonatal care. Less is known about methadone, a clinically relevant opioid analgesic, especially during neonatal development. This study was undertaken to determine the neonatal respiratory effects of methadone. We hypothesize that methadone is equipotent to morphine, compared to our previous morphine results in the same animal model, but has a much longer duration of action, due to its longer elimination half-life. Neonatal guinea pigs (3-14 days old) randomly received a single subcutaneous dose of methadone or saline. Using a non-invasive plethysmographic method, we measured ventilatory and metabolic parameters before injection and at intervals for 32 hr after injection while pups breathed "room air" or 5% CO(2) gas mixtures. Methadone-induced depression of ventilation was most evident during 5% CO(2) challenge. The onset of drug effects was within 15 min for all ages and doses, but the duration of action decreased with age. While the depth of methadone-induced respiratory depression did not depend on pup age, the control of breathing was different in 3-day-old pups, where inspiratory time increased fourfold; twice that of older pups. We conclude that methadone induces a naloxone reversible respiratory depression in guinea pig neonates and, in the very young, causes an abnormal breathing pattern due to changes in respiratory timing. Methadone is more potent than morphine with respect to neonatal respiratory depression, but surprisingly, the duration of methadone action was not longer than morphine.

  12. Evaluation of rhesus monkey and guinea pig hepatic cytosol fractions as models for human aldehyde oxidase.

    PubMed

    Choughule, Kanika V; Barr, John T; Jones, Jeffrey P

    2013-10-01

    Aldehyde oxidase (AOX) is a cytosolic enzyme expressed across a wide range of species, including guinea pig and rhesus monkey. These species are believed to be the best preclinical models for studying human AOX-mediated metabolism. We compared AOX activity in rhesus monkeys, guinea pigs, and humans using phthalazine and N-[2-(dimethylamino)ethyl]acridone-4-carboxamide (DACA) as substrates and raloxifene as an inhibitor. Michaelis-Menten kinetics was observed for phthalazine oxidation in rhesus monkey, guinea pig, and human liver cytosol, whereas substrate inhibition was seen with DACA oxidase activity in all three livers. Raloxifene inhibited phthalazine and DACA oxidase activity uncompetitively in guinea pig, whereas mixed-mode inhibition was seen in rhesus monkey. Our analysis of the primary sequence alignment of rhesus monkey, guinea pig, and human aldehyde oxidase isoform 1 (AOX1) along with homology modeling has led to the identification of several amino acid residue differences within the active site and substrate entrance channel of AOX1. We speculate that some of these residues might be responsible for the differences observed in activity. Overall, our data indicate that rhesus monkeys and guinea pigs would overestimate intrinsic clearance in humans and would be unsuitable to use as animal models. Our study also showed that AOX metabolism in species is substrate-dependent and no single animal model can be reliably used to predict every drug response in humans.

  13. Evaluation of Rhesus Monkey and Guinea Pig Hepatic Cytosol Fractions as Models for Human Aldehyde Oxidase

    PubMed Central

    Choughule, Kanika V.; Barr, John T.

    2013-01-01

    Aldehyde oxidase (AOX) is a cytosolic enzyme expressed across a wide range of species, including guinea pig and rhesus monkey. These species are believed to be the best preclinical models for studying human AOX-mediated metabolism. We compared AOX activity in rhesus monkeys, guinea pigs, and humans using phthalazine and N-[2-(dimethylamino)ethyl]acridone-4-carboxamide (DACA) as substrates and raloxifene as an inhibitor. Michaelis-Menten kinetics was observed for phthalazine oxidation in rhesus monkey, guinea pig, and human liver cytosol, whereas substrate inhibition was seen with DACA oxidase activity in all three livers. Raloxifene inhibited phthalazine and DACA oxidase activity uncompetitively in guinea pig, whereas mixed-mode inhibition was seen in rhesus monkey. Our analysis of the primary sequence alignment of rhesus monkey, guinea pig, and human aldehyde oxidase isoform 1 (AOX1) along with homology modeling has led to the identification of several amino acid residue differences within the active site and substrate entrance channel of AOX1. We speculate that some of these residues might be responsible for the differences observed in activity. Overall, our data indicate that rhesus monkeys and guinea pigs would overestimate intrinsic clearance in humans and would be unsuitable to use as animal models. Our study also showed that AOX metabolism in species is substrate-dependent and no single animal model can be reliably used to predict every drug response in humans. PMID:23918666

  14. Protective effects of isorhynchophylline on cardiac arrhythmias in rats and guinea pigs.

    PubMed

    Gan, Runtao; Dong, Guo; Yu, Jiangbo; Wang, Xu; Fu, Songbin; Yang, Shusen

    2011-09-01

    As one important constituent extracted from a traditional Chinese medicine, Uncaria Rhynchophylla Miq Jacks, isorhynchophylline has been used to treat hypertension, epilepsy, headache, and other illnesses. Whether isorhynchophylline protects hearts against cardiac arrhythmias is still incompletely investigated. This study was therefore aimed to examine the preventive effects of isorhynchophylline on heart arrhythmias in guinea pigs and rats and then explore their electrophysiological mechanisms. In vivo, ouabain and calcium chloride were used to establish experimental arrhythmic models in guinea pigs and rats. In vitro, the whole-cell patch-lamp technique was used to study the effect of isorhynchophylline on action potential duration and calcium channels in acutely isolated guinea pig and rat cardiomyocytes. The dose of ouabain required to induce cardiac arrhythmias was much larger in guinea pigs administered with isorhynchophylline. Additionally, the onset time of cardiac arrhythmias induced by calcium chloride was prolonged, and the duration was shortened in rats pretreated with isorhynchophylline. The further study showed that isorhynchophylline could significantly decrease action potential duration and inhibit calcium currents in isolated guinea pig and rat cardiomyocytes in a dose-dependent manner. In summary, isorhynchophylline played a remarkably preventive role in cardiac arrhythmias through the inhibition of calcium currents in rats and guinea pigs.

  15. A novel guinea pig macrophage-specific polymorphic molecule. I. Biochemistry, genetics, and tissue distribution.

    PubMed

    Jensen, L A; Schwartz, B D

    1988-02-15

    In the course of studying Ia molecules from strain 2 and strain 13 guinea pig macrophages, with the intent of comparing them to B cell Ia molecules, it was observed that guinea pig alloserum prepared by cross-immunization of guinea pig lymphocyte Ag non-identical inbred guinea pigs immunoprecipitated not only conventional class I and class II molecules, but also a 98,000-Da molecule, termed gp98. Two different forms of the molecule were detected, indicating it is polymorphic. The genes encoding gp98 were shown not to be linked to the guinea pig lymphocyte Ag complex. The molecule gp98 was found on macrophages within populations of peritoneal exudate cells, resident peritoneal cells, bone marrow cells, and spleen. All gp98-bearing macrophages were also Ia-positive. However, only a subpopulation of macrophages bore gp98. The gp98 was not found on Ly-1 or Ig-bearing cells, indicating that B and T cells do not bear Ia. Thus, gp98 appears to be a highly immunogenic polymorphic macrophage-specific molecule that allows the characterization of guinea pig macrophage subsets.

  16. Effects of ascorbic acid deficiency on methyl mercury dicyandiamide toxicosis in guinea pigs.

    PubMed

    Yamini, B; Sleight, S D

    1984-07-01

    Methylmercury dicyandiamide (MMD) when given intraperitoneally at a dosage of 4 mg/kg of body weight at weekly intervals for 3 weeks resulted in death of guinea pigs fed an ascorbic acid deficient diet. Controls fed an ascorbic acid deficient diet survived during this period as did guinea pigs given MMD and fed an ascorbic acid adequate diet. In a second experiment, guinea pigs fed an ascorbic acid deficient diet containing 22 ppm of MMD died within 26 days and had severe hemorrhagic and ulcerative gastroenteritis and coagulative necrosis of the liver. Ascorbic acid deficient controls died at 34 days. The MMD-containing ascorbic acid adequate diet killed guinea pigs in 150 days. Guinea pigs fed an ascorbic acid deficient diet with 44 ppm of MMD died within 20 days with acute neurologic signs. Pathologic changes were mostly in the gray matter. Guinea pigs fed MMD and a diet with adequate ascorbic acid survived for 38 days whereas the ascorbic acid deficient controls survived for 47 days. Results indicate that ascorbic acid deficiency can be a factor in the location and severity of clinical signs and lesions of MMD.

  17. Anti-anaphylactic action of nordihydroguaiaretic acid in antigen sensitized guinea pigs.

    PubMed

    Bergren, Dale R; Valentine, Jimmie L

    2016-12-01

    Therapeutic natural products and medicinal herbs has gained popularity. The anti-antigenic action of the plant alkaloid nordihydroguaiaretic acid (NDGA) was studied in ovalbumin (OA)-sensitized guinea pigs. In one series of experiments conscious, non-sedated guinea pigs were challenged with OA aerosol. Specific airway resistance (SRAW) was monitored using a two-chambered whole-body plethysmograph. OA aerosol increased SRAW above that produced by vehicle administration. Prior NDGA administration by a 1min 0.9% aerosol (w/vol) attenuated the increase in SRAW resulting from OA challenge. In the anesthetized guinea pig pretreated with indomethacin, pyrilamine and propranolol, intravenous OA injection increased intra-tracheal pressure above vehicle injection. Intravenous NDGA administration (5mg/kg) reduced the intra-tracheal pressure increases. In a third series of experiments plasma leukotriene C4 was measured by radio-immunoassay in 3 groups challenged with OA aerosol: vehicle-treated OA-sensitized, OA-sensitized receiving NDGA and vehicle treated guinea pigs. NDGA pretreatment reduced plasma LTC4 in response to OA challenge in OA sensitized guinea pigs. This study demonstrates that NDGA is an effective antigenic agent when given by aerosol or intravenous injection in either conscious or anesthetized guinea pigs, respectively. The mechanism of action of NDGA is presumed primarily be due to the blockage of 5-lipoxygenase and therefore the synthesis of leukotrienes. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Increased Severity of Tuberculosis in Guinea Pigs with Type 2 Diabetes

    PubMed Central

    Podell, Brendan K.; Ackart, David F.; Obregon-Henao, Andres; Eck, Sarah P.; Henao-Tamayo, Marcela; Richardson, Michael; Orme, Ian M.; Ordway, Diane J.; Basaraba, Randall J.

    2015-01-01

    Impaired glucose tolerance and type 2 diabetes were induced in guinea pigs to model the emerging comorbidity of Mycobacterium tuberculosis infection in diabetic patients. Type 2 diabetes mellitus was induced by low-dose streptozotocin in guinea pigs rendered glucose intolerant by first feeding a high-fat, high-carbohydrate diet before M. tuberculosis exposure. M. tuberculosis infection of diabetic guinea pigs resulted in severe and rapidly progressive tuberculosis (TB) with a shortened survival interval, more severe pulmonary and extrapulmonary pathology, and a higher bacterial burden compared with glucose-intolerant and nondiabetic controls. Compared with nondiabetics, diabetic guinea pigs with TB had an exacerbated proinflammatory response with more severe granulocytic inflammation and higher gene expression for the cytokines/chemokines interferon-γ, IL-17A, IL-8, and IL-10 in the lung and for interferon-γ, tumor necrosis factor-α, IL-8, and monocyte chemoattractant protein-1 in the spleen. TB disease progression in guinea pigs with impaired glucose tolerance was similar to that of nondiabetic controls in the early stages of infection but was more severe by day 90. The guinea pig model of type 2 diabetes–TB comorbidity mimics important features of the naturally occurring disease in humans. This model will be beneficial in understanding the complex pathogenesis of TB in diabetic patients and to test new strategies to improve TB and diabetes control when the two diseases occur together. PMID:24492198

  19. Vaccination with Trypanosoma rangeli induces resistance of guinea pigs to virulent Trypanosoma cruzi.

    PubMed

    Basso, B; Moretti, E; Fretes, R

    2014-01-15

    Chagas' disease, endemic in Latin America, is spread in natural environments through animal reservoirs, including marsupials, mice and guinea pigs. Farms breeding guinea pigs for food are located in some Latin-American countries with consequent risk of digestive infection. The aim of this work was to study the effect of vaccination with Trypanosoma rangeli in guinea pigs challenged with Trypanosoma cruzi. Animals were vaccinated with fixated epimastigotes of T. rangeli, emulsified with saponin. Controls received only PBS. Before being challenged with T. cruzi, parasitemia, survival rates and histological studies were performed. The vaccinated guinea pigs revealed significantly lower parasitemia than controls (p<0.0001-0.01) and a discrete lymphomonocytic infiltrate in cardiac and skeletal muscles was present. In the chronic phase, the histological view was normal. In contrast, control group revealed amastigote nests and typical histopathological alterations compatible with chagasic myocarditis, endocarditis and pericarditis. These results, together with previous works in our laboratory, show that T. rangeli induces immunoprotection in three species of animals: mice, guinea pigs and dogs. The development of vaccines for use in animals, like domestic dogs and guinea pigs in captivity, opens up new opportunities for preventive tools, and could reduce the risk of infection with T. cruzi in the community. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Immunogenicity of guinea pig cells transformed in culture by chemical carcinogens

    SciTech Connect

    Ohanian, S.H.; McCabe, R.P.; Evans, C.H.

    1981-12-01

    The immunogenicity of inbred strain 2/N guinea pig fibroblasts transformed to the malignant state in vitro by chemical carcinogens was evaluated with the use of a variety of in vivo and in vitro methods including delayed-type hypersensitivity skin and tumor transplantation tests and analysis of antibody production by immunofluorescence, complement fixation, and staphylococcal protein A binding tests. Neoplastic transformation was induced by direct treatment of cells in culture with benzo(a)pyrene, 3-methylcholanthrene, or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or by the host-mediated method by which fetuses were exposed to diethylnitrosamine or MNNG in vivo prior to cell culture. Rabbits and syngeneic guinea pigs were inoculated with unirradiated and X-irradiated clonally derived cells. Delayed hypersensitivity skin reactions to immunizing or other cells were equivalent in immunized or control guinea pigs, and no protection to tumor outgrowth from a challenge inoculum of immunizing cells was observed. Antibody activity induced in the sera of immunized guinea pigs was cross-reactive and removed by absorption with nontumorigenic cells. Rabbit anitsera after absorption with fetal guinea pig cells were nonreactive with the specific immunizing or other cultured cells. Chemical carcinogen-induced neoplastic transformation of guinea pig cells can, therefore, occur without formation of detectable, individually distinct cell surface tumor-specific neoantigens.

  1. Immunogenicity of guinea pig cells transformed in culture by chemical carcinogens

    SciTech Connect

    Ohanian, S.H.; McCabe, R.P.; Evans, C.H.

    1981-12-01

    The immunogenicity of inbred strain 2/N guinea pig fibroblasts transformed to the malignant state in vitro by chemical carcinogens was evaluated with the use of a variety of in vivo and in vitro methods including delayed-type hypersensitivity skin and tumor transplantation tests and analysis of antibody production by immunofluorescence, complement fixation, and staphylococcal protein A binding tests. Neoplastic transformation was induced by direct treatment of cells in culture with benzo(a)pyrene, 3-methylcholanthrene, or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or by the host-mediated method by which fetuses were exposed to diethylnitrosamine or MNNG in vivo prior to cell culture. Rabbits and syngeneic guinea pigs were inoculated with unirradiated and X-irradiated clonally derived cells. Delayed hypersensitivity skin reactions to immunizing or other cells were equivalent in immunized or control guinea pigs, and no protection to tumor outgrowth from a challenge inoculum of immunizing cells was observed. Antibody activity induced in the sera of immunized guinea pigs was cross-reactive and removed by absorption with nontumorigenic cells. Rabbit antisera after absorption with fetal guinea pig cells were nonreactive with the specific immunizing or other culture cells. Chemical carcinogen-induced neoplastic transformation of guinea pig cells can, therefore, occur without formation of detectable, individually distinct cell surface tumor-specific neoantigens.

  2. [Establishing an experimental guinea pig model of dermatophytosis Using Trichophyton rubrum].

    PubMed

    Chen, Xian-Jin; Shen, Yong-Nian; Lü, Gui-Xia; Liu, Wei-Da

    2008-10-01

    To construct an animal model infected by Trichophyton rubrum. Three different strains of Trichophyton rubrum were separated from clinical specimen for the infection of guinea pigs. Corticosteroids were given before and after the construction of animal model to facilitate the infection. Direct microscopy, culture, and histopathologic methods were adopted to verify the construction. Ten days after the inoculation of Trichophyton rubrum, with the intervention of corticosteroid, the guinea pigs were examined. Prominent scales and inflammation could be seen on the inoculation site of the Trichophyton rubrum infected guinea pig. Scales and hairs of Trichophyton rubrum infected guinea pig dealt with 10% potassium hydroxide, hypha out of the hair and microconidia or hypha in the hair shaft could be seen. Seven days after the inoculation of scales and hair on SDA plate, cultures of Trichophyton rubrum showed that the colonial morphology were identical to the original dermatophytes. PAS staining of infected guinea pig skin tissue showed that hypha and microconidia could be seen in the infundibula and hair root. With the intervention of corticosteroid, a stable guinea pig model infected by Trichophyton rubrum were successfully constructed.

  3. Adeno-associated virus transformation into the normal miniature pig and the normal guinea pigs cochlea via scala tympani.

    PubMed

    Shi, Xunbei; Wu, Nan; Zhang, Yue; Guo, Weiwei; Lin, Chang; Yang, Shiming

    2017-09-01

    To investigate the expression of the miniature pig cochlea after AAV1 transfect into the cochlea via round window membrane (RWM). Twenty miniature pigs are equally divided into four experimental groups. Twelve miniature pigs are equally divided into four control groups. Each pig was transfected with the AAV1 in the experimental group via RWM and each pig was transduced with the artificial perilymph in the control group. The expression of green fluorescent protein (GFP) was observed at 2 weeks, 3 weeks and 4 weeks, respectively. Likewise, AAV1 was delivered into the guinea pigs cochleas using the same method, and the results were compared with that of the miniature pigs. The expression was mainly in the inner hair cells of the miniature pig. The expression of GFP began to appear at 2 weeks, reached the peak at 3 weeks. It also expressed in Hensen's cells, inner pillar cells, outer pillar cells, spiral limbus, and spiral ligament. In the meanwhile, AAV1 was delivered into guinea pig cochlea via the same method, and AAV1 was also expressed in the inner hair cells. But the expression peaked at 2 weeks, and the efficiency of the inner hair cell transfection was higher than that of the pig. AAV1 can be transformed into miniature pig cochlea via scala tympani by the RWM method efficiently.

  4. Omecamtiv Mecarbil Abolishes Length-Mediated Increase in Guinea Pig Cardiac Myofiber Ca(2+) Sensitivity.

    PubMed

    Gollapudi, Sampath K; Reda, Sherif M; Chandra, Murali

    2017-08-22

    Omecamtiv mecarbil (OM) is a pharmacological agent that augments cardiac contractile function by enhancing myofilament Ca(2+) sensitivity. Given that interventions that increase myofilament Ca(2+) sensitivity have the potential to alter length-dependent activation (LDA) of cardiac myofilaments, we tested the influence of OM on this fundamental property of the heart. This is significant not only because LDA is prominent in cardiac muscle but also because it contributes to the Frank-Starling law, a mechanism by which the heart increases stroke volume in response to an increase in venous return. We measured steady-state and dynamic contractile indices in detergent-skinned guinea pig (Cavia porcellus) cardiac muscle fibers in the absence and presence of 0.3 and 3.0 μM OM at two different sarcomere lengths (SLs), short SL (1.9 μm) and long SL (2.3 μm). Myofilament Ca(2+) sensitivity, as measured by pCa50 (-log of [Ca(2+)]free concentration required for half-maximal activation), increased significantly at both short and long SLs in OM-treated fibers when compared to untreated fibers; however, the magnitude of increase in pCa50 was twofold greater at short SL than at long SL. A consequence of this greater increase in pCa50 at short SL was that pCa50 did not increase any further at long SL, suggesting that OM abolished the SL dependency of pCa50. Furthermore, the SL dependency of rate constants of cross-bridge distortion dynamics (c) and force redevelopment (ktr) was abolished in 0.3-μM-OM-treated fibers. The negative impact of OM on the SL dependency of pCa50, c, and ktr was also observed in 3.0-μM-OM-treated fibers, indicating that cooperative mechanisms linked to LDA were altered by the OM-mediated effects on cardiac myofilaments. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  5. The antigenicity in guinea pigs and monkeys of three mycobacterial polysaccharides purified by affinity chromatography with concanavalin A.

    PubMed

    Daniel, T M

    1975-06-01

    The antigenicity of 3 polysaccharides purified from culture filtrates of Mycobacterim tuberculosis by affinity chromatography using a concanavalin A-agarose absorbent was studied. All 3 purified polysaccharides were found to be potent elicitors of delayed skin test reactions in sensitized guinea pigs and in a tuberculos monkey. This antigenicity could not be attributed to contaminating protein. Small dermal reactions were also observed in control guinea pigs. All 3 polysaccharides reacted with precipitating antibody in guinea pig sera, the antigenic specificity observed with the guinea pig sera differing from that demonstrated with reference goat antiserum. The 3 polysaccharides were also demonstrated to contain hemagglutination antigenic sites.

  6. Protein A Suppresses Immune Responses during Staphylococcus aureus Bloodstream Infection in Guinea Pigs

    PubMed Central

    Kim, Hwan Keun; Falugi, Fabiana; Thomer, Lena; Missiakas, Dominique M.

    2015-01-01

    ABSTRACT   Staphylococcus aureus infection is not associated with the development of protective immunity, and disease relapses occur frequently. We hypothesize that protein A, a factor that binds immunoglobulin Fcγ and cross-links VH3 clan B cell receptors (IgM), is the staphylococcal determinant for host immune suppression. To test this, vertebrate IgM was examined for protein A cross-linking. High VH3 binding activity occurred with human and guinea immunoglobulin, whereas mouse and rabbit immunoglobulins displayed little and no binding, respectively. Establishing a guinea pig model of S. aureus bloodstream infection, we show that protein A functions as a virulence determinant and suppresses host B cell responses. Immunization with SpAKKAA, which cannot bind immunoglobulin, elicits neutralizing antibodies that enable guinea pigs to develop protective immunity. Importance  Staphylococcus aureus is the leading cause of soft tissue and bloodstream infections; however, a vaccine with clinical efficacy is not available. Using mice to model staphylococcal infection, earlier work identified protective antigens; however, corresponding human clinical trials did not reach their endpoints. We show that B cell receptor (IgM) cross-linking by protein A is an important immune evasion strategy of S. aureus that can be monitored in a guinea pig model of bloodstream infection. Further, immunization with nontoxigenic protein A enables infected guinea pigs to elicit antibody responses that are protective against S. aureus. Thus, the guinea pig model may support preclinical development of staphylococcal vaccines. PMID:25564466

  7. Analysis of humoral immune responses to LM1 ganglioside in guinea pigs.

    PubMed

    Gu, Yajuan; Chen, Zi-Wei; Siegel, Allan; Koshy, Ranie; Ramirez, Cristhian; Raabe, Timothy D; Devries, George H; Ilyas, Amjad A

    2012-05-15

    Guillain-Barré syndrome (GBS) is an autoimmune-mediated disease triggered by a preceding infection. A substantial body of evidence implicates antibodies to various gangliosides in subtypes of GBS. A significant proportion of patients with acute demyelinating subset of GBS have IgG antibodies against peripheral nervous system myelin specific neolactogangliosides such as LM1 and Hex-LM1. Although anti-neolactoganglioside antibodies in GBS were described more than two decades ago, their pathogenic role in neuropathy remains unknown due to the lack of suitable experimental models. In this study, we immunized ten guinea pigs with purified LM1 ganglioside mixed with keyhole limpet hemocyanin (KLH) and emulsified in complete Freund's adjuvant (CFA). Control guinea pigs were injected with KLH emulsified in CFA only. The animals were bled every four week intervals. The animals were boosted 3 times every four weeks. Experiments were terminated four months after initial immunization. Nine of 10 guinea pigs immunized with LM1 exhibited antibody responses to LM1. Anti-LM1 IgG titers in nine guinea pigs ranged from 1:400 to 1:12,800 at 16-weeks after initial immunization. Anti-LM1 antibodies were predominantly of IgG2 subclass. One guinea pig with the highest levels of IgG antibodies exhibited mild signs of neuropathy. There was no evidence of demyelination or inflammation in the sciatic nerves of LM1-immunized guinea pigs. Anti-LM1 antibodies bound to rat sciatic nerve myelin and to isolated rat Schwann cells. In summary, our findings suggest that relatively high levels of anti-LM1 IgG antibodies can be induced in guinea pigs and that LM1 is localized in peripheral nerve myelin and in Schwann cells. Further studies are needed to determine the pathogenic potential of anti-neolactoganglioside antibodies in neuropathy.

  8. Deterioration of epithelium mediated mechanisms in diabetic-antigen sensitized airways of guinea pigs.

    PubMed

    Bano, Saidullah; Swati, Omanwar; Kambadur, Muralidhar; Mohammad, Fahim

    2016-01-01

    The onset of diabetes causes disruption of respiratory epithelial mediators. The present study investigates whether diabetes modifies the epithelium mediated bronchial responses in hyper-reactive airway smooth muscle (ASM) primarily through nitric oxide (NO), cyclooxygenase (COX), and epithelium derived hyperpolarizing factor (EpDHF) pathways. Experimental model of guinea pigs having hyper-reactive airways with or without diabetes were developed. The responses of tracheal rings to cumulative concentrations of acetylcholine (ACh) and isoproterenol (IP) in the presence and absence of epithelium and before and after incubation with NO, K(+)ATP and COX inhibitors, N-(ω)-Nitro-L-arginine methyl ester (L-NAME; 100 μM), glybenclamide (10 μM) and indomethacin (100 μM) were assessed. In diabetic guinea pigs with hyper-reactive airways, a decrease in ACh induced bronchoconstriction was observed after epithelium removal and after incubation with L-NAME/indomethacin, suggesting damage to NO/COX pathways. Hyper-reactivity did not alter the response of trachea to ACh but affected the response to IP which was further reduced in hyper-reactive animals with diabetes. The ASM response to IP after glybenclamide treatment did not alter in hyper-reactive guinea pigs and diabetic guinea pigs with hyper-reactive airways, suggesting damage to the EpDHF pathway. Treatment with indomethacin reduced IP response in the hyper-reactive model, and did not produce any change in diabetic model with hyper-reactive airways, indicating further disruption of the COX pathway. EpDHF pathway is damaged in hyper-reactive guinea pigs and in diabetic guinea pigs with hyper-reactive airways. Diabetes further aggravates the NO and COX mediated pathways in diabetic guinea pigs with hyper-reactive airways.

  9. Airway hyperresponsiveness induced by repeated esophageal infusion of HCl in guinea pigs.

    PubMed

    Cheng, Yan-Mei; Cao, Ai-Li; Zheng, Jian-Pu; Wang, Hong-Wei; Sun, Yong-Shun; Liu, Chun-Fang; Zhang, Bei-Bei; Wang, Yi; Zhu, Sheng-Liang; Wu, Da-Zheng

    2014-11-01

    Gastroesophageal reflux is a common disorder closely related to chronic airway diseases, such as chronic cough, asthma, chronic bronchitis, and chronic obstructive disease. Indeed, gastroesophageal acid reflux into the respiratory tract causes bronchoconstriction, but the underlying mechanisms have still not been clarified. This study aimed to elucidate functional changes of bronchial smooth muscles (BSMs) isolated from guinea pigs in an animal model of gastroesophageal reflux. The marked airway inflammation, hyperresponsiveness and remodeling were observed after guinea pigs were exposed to intraesophageal HCl infusion for 14 days. In addition, contractile responses to acetylcholine (ACh), KCl, electrical field stimulation, and extracellular Ca(2+) were greater in guinea pigs infused with HCl compared with control groups. The L-type voltage-dependent Ca(2+) channels (L-VDCC) blocker, nicardipine, significantly inhibited ACh- and Ca(2+)-enhanced BSM contractions in guinea pigs infused with HCl. The Rho-kinase inhibitor, Y27632, attenuated ACh-enhanced BSM contractions in guinea pigs infused with HCl. Moreover, mRNA and protein expressions for muscarinic M2 and M3 receptors, RhoA, and L-VDCC in BSM were detected by real-time PCR and Western blot. Expressions of mRNA and protein for muscarinic M3 receptors, RhoA, and L-VDCC were greater than in BSM of HCl-infused guinea pigs, whereas levels of muscarinic M2 receptors were unchanged. We demonstrate that acid infusion to the lower esophagus and, subsequently, microaspiration into the respiratory tract in guinea pigs leads to airway hyperresponsiveness and overactive BSM. Functional and molecular results indicate that overactive BSM is the reason for enhancement of extracellular Ca(2+) influx via L-VDCC and Ca(2+) sensitization through Rho-kinase signaling.

  10. The ototoxic effect of boric acid solutions applied into the middle ear of guinea pigs.

    PubMed

    Oztürkcan, Sedat; Dündar, Riza; Katilmis, Hüseyin; Ilknur, Ali Ekber; Aktaş, Sinem; Haciömeroğlu, Senem

    2009-05-01

    This study analyzed the ototoxic effects of boric acid solutions. Boric acid solutions have been used as otologic preparations for many years. Boric acid is commonly found in solutions prepared with alcohol or distilled water but can also be found in a powder form. These preparations are used for both their antiseptic and acidic qualities in external and middle ear infections. We investigated the ototoxic effect of boric acid solutions on guinea pigs. We are unaware of any similar, previously published study of this subject in English. The study was conducted on 28 young albino guinea pigs. Prior to application of the boric acid solution under general anesthesia, an Auditory Brainstem Response (ABRs) test was applied to the right ear of the guinea pigs. Following the test, a perforation was created on the tympanic membrane of the right ear of each guinea pig and small gelfoam pieces were inserted into the perforated area. Test solutions were administered to the middle ear for 10 days by means of a transcanal route. Fifteen days after inserting the gelfoams in all of the guinea pigs, we anasthesized the guinea pigs and removed the gelfoams from the perforated region of the ear and then performed an ABRs on each guinea pig. The ABRs were within the normal range before the applications. After the application, no significant changes were detected in the ABRs thresholds in neither the saline group nor the group administered boric acid and distilled water solution; however, significant changes were detected in the ABRs thresholds of the Gentamicine and boric acid and alcohol solution groups. We believe that a 4% boric acid solution prepared with distilled water can be a more reliable preparation than a 4% boric acid solution prepared with alcohol.

  11. Novel organization and processing of the guinea pig pancreatic polypeptide precursor.

    PubMed

    Blackstone, C D; Seino, S; Takeuchi, T; Yamada, T; Steiner, D F

    1988-02-25

    Studies on New World hystricomorph rodents have revealed interesting structural divergences in the peptide hormones of the islets of Langerhans, particularly with respect to insulin and glucagon. Herein we report the isolation and sequencing of a cDNA encoding the precursor of pancreatic polypeptide (PP) from a guinea pig pancreas cDNA library. The 126-residue precursor sequence is predicted to include a 26-residue NH2-terminal signal peptide followed by the 36-amino acid PP hormonal sequence and a large COOH-terminal extension. The sequence identity between guinea pig and human PP is 89% (32/36 residues), and the predicted sequence is in agreement with that reported by Eng et al. (Eng, J., Huang, C.-G., Pan, Y.-C. E., Hulmes, J. D., and Yalow, R. S. (1987) Peptides 8, 165-168). In contrast, the icosapeptide domain in the guinea pig precursor exhibits only 40% (8/20) identity with the corresponding human precursor domain, and the COOH-terminal extension differs greatly in both sequence and size. The guinea pig precursor lacks the monobasic processing site (Pro-Arg) found at the COOH terminus of the icosapeptide domain in human, ovine, canine, and feline proPP. An icosapeptide is thus not likely to be liberated as such from this precursor. Of particular interest in guinea pig proPP is the substitution of serine for arginine at the dibasic amino acid processing site on the COOH-terminal side of the PP domain. Results of radioimmunoassays of gel-filtered protein fractions from a guinea pig pancreas extract indicate that efficient proteolytic cleavage takes place at this Lys-Ser site and that mature guinea pig PP is normally carboxyamidated.

  12. Expression Profile of the Integrin Receptor Subunits in the Guinea Pig Sclera.

    PubMed

    Wang, Kevin K; Metlapally, Ravikanth; Wildsoet, Christine F

    2017-06-01

    The ocular dimensional changes in myopia reflect increased scleral remodeling, and in high myopia, loss of scleral integrity leads to biomechanical weakening and continued scleral creep. As integrins, a type of cell surface receptors, have been linked to scleral remodeling, they represent potential targets for myopia therapies. As a first step, this study aimed to characterize the integrin subunits at the messenger RNA level in the sclera of the guinea pig, a more recently added but increasingly used animal model for myopia research. Primers for α and β integrin subunits were designed using NCBI/UCSC Genome Browser and Primer3 software tools. Total RNA was extracted from normal scleral tissue and isolated cultured scleral fibroblasts, as well as liver and lung, as reference tissues, all from guinea pig. cDNA was produced by reverse transcription, PCR was used to amplify products of predetermined sizes, and products were sequenced using standard methods. Guinea pig scleral tissue expressed all known integrin alpha subunits except αD and αE. The latter integrin subunits were also not expressed by cultured guinea pig scleral fibroblasts; however, their expression was confirmed in guinea pig liver. In addition, isolated cultured fibroblasts did not express integrin subunits αL, αM, and αX. This difference between results for cultured cells and intact sclera presumably reflects the presence in the latter of additional cell types. Both guinea pig scleral tissue and isolated scleral fibroblasts expressed all known integrin beta subunits. All results were verified through sequencing. The possible contributions of integrins to scleral remodeling make them plausible targets for myopia prevention. Data from this study will help guide future ex vivo and in vitro studies directed at understanding the relationship between scleral integrins and ocular growth regulation in the guinea pig model for myopia.

  13. Contractile effects of cysteamine on the guinea-pig ileum.

    PubMed Central

    Bakich, V.; Brown, J.; Kwok, Y. N.; McIntosh, C.; Nishimura, E.

    1984-01-01

    Cysteamine (beta-mercaptoethylamine HCl) (1.0-40.0 mM) induced a concentration-dependent increase in tonic and phasic contractions of segments of guinea-pig ileum in vitro. Myenteric plexus-longitudinal muscle (MPLM) preparations also responded with an increase in tonic contractions but phasic contractions were either greatly reduced or absent, indicating that these were a response of the circular muscle. Atropine (5 microM) inhibited the cysteamine-induced contractions, whereas hexamethonium and guanethidine had no effect, suggesting that cysteamine was acting at least partly via a cholinergic mechanism involving muscarinic receptors. Tetrodotoxin increased the phasic contractions of ileal segments, but had no effect on the tonic component. Treatment of MPLM preparations with morphine (1 microM) resulted in a small reduction in responsiveness to cysteamine, and blocked electrically-induced contractions by at least 90%. Since morphine acts by inhibiting acetylcholine release via hyperpolarization of intrinsic neurones, a small but significant part of the cysteamine-induced contractions probably resulted from stimulation of acetylcholine release from intrinsic neurones. Following a response to high cysteamine concentrations (greater than 15 mM) tissues were refractory to subsequent cysteamine administration. Cross-desensitization between cysteamine and acetylcholine also occurred, as short-term (1-3 min) incubation of MPLM preparations with high concentrations of either compound (1-10 microM acetylcholine or 20 mM cysteamine) resulted in a reduced responsiveness to both. A reduced sensitivity to acetylcholine or cysteamine was obtained following long-term (45 min) incubation with acetylcholine (1 microM). Removal of Na+ from the incubation medium negated this effect. In contrast, the refractoriness to acetylcholine or cysteamine following long-term (45 min) incubation with cysteamine (20 mM) was accentuated in low Na+ medium. It is suggested that cysteamine induces

  14. Inhibition of some aspects of acute inflammation of guinea-pig lung by intraperitoneal dexamethasone and mifepristone: demonstration of agonist activity of mifepristone in the guinea-pig.

    PubMed

    Whelan, C J; Hughes, S C; Wren, G P

    1995-03-01

    We have determined the inhibitory activity of dexamethasone as an inhibitor of histamine-induced plasma protein extravasation (PPE) in guinea-pig lung and skin, and of lipopolysaccharide (LPS)-induced neutrophilia and platelet activating factor (PAF)-induced eosinophilia in guinea-pig lungs. Dexamethasone inhibited PAF-induced eosinophilia in guinea-pig lung (ED50 1.4 mg/kg i.p.). Higher doses of dexamethasone were required to inhibit LPS-induced neutrophilia (ED50 10.8 mg/kg i.p.). However, at doses up to 150 mg/kg i.p. dexamethasone did not inhibit histamine-induced plasma protein extravasation (PPE) in guinea-pig lung, but did inhibit PPE in guinea-pig skin. These preparations have previously been shown to be equally sensitive to inhibition by the beta 2-adrenoceptor agonist salmeterol. Dexamethasone inhibited PAF-induced eosinophilia (5 mg/kg) or LPS-induced neutrophilia (50 mg/kg) when given 3 h or 1 h prior to challenge. Inhibitory activity was lost when dexamethasone was administered 23 h prior to LPS or 1 h after PAF. The glucocorticoid antagonist mifepristone (1-100 mg/kg i.p.) caused dose-related inhibition of PAF-induced eosinophilia but not of LPS-induced neutrophilia. The highest dose of mifepristone used (100 mg/kg) did not reverse the inhibitory actions of dexamethasone (50 mg/kg) on LPS-induced neutrophilia. We suggest that the different inhibitory activity of dexamethasone in the preparations studied indicates differences in the sensitivity of the target cells involved to inhibition by dexamethasone. We also suggest that inhibition of PAF-induced eosinophilia by mifepristone reflects the partial agonist activity of this agent, demonstrated by others in different experimental systems.

  15. Demonstration of a specific C3a receptor on guinea pig platelets

    SciTech Connect

    Fukuoka, Y.; Hugli, T.E.

    1988-05-15

    Guinea pig platelets reportedly contain receptors specific for the anaphylatoxin C3a based on both ligand-binding studies and functional responses. A portion of the human 125I-C3a that binds to guinea pig platelets is competitively displaced by excess unlabeled C3a; however, the majority of ligand uptake was nonspecific. Uptake of 125I-C3a by guinea pig platelets is maximal in 1 min, and stimulation of guinea pig platelets by thrombin, ADP, or the Ca2+ ionophore A23187 showed little influence on binding of the ligand. Scatchard analysis indicated that approximately 1200 binding sites for C3a exist per cell with an estimated Kd of 8 x 10(-10) M. Human C3a des Arg also binds to guinea pig platelets, but Scatchard analysis indicated that no specific binding occurred. Because the ligand-binding studies were complicated by high levels of nonspecific uptake, we attempted to chemically cross-link the C3a molecule to a specific component on the platelet surface. Cross-linkage of 125I-C3a to guinea pig platelets with bis(sulfosuccinimidyl)suberate revealed radioactive complexes at 105,000 and 115,000 m.w. on SDS-PAGE gels by autoradiographic analysis. In the presence of excess unlabeled C3a, complex formation was inhibited. No cross-linkage could be demonstrated between the inactive 125I-C3a des Arg and the putative C3a-R on guinea pig platelets. Human C3a, but not C3a des Arg induces serotonin release and aggregation of the guinea pig platelets. Human C3a was unable to induce either serotonin release or promote aggregation of human platelets. Uptake of human 125I-C3a by human platelets was not saturable, and Scatchard analysis was inconclusive. Attempts to cross-link 125I-C3a to components on the surface of human platelets also failed to reveal a ligand-receptor complex. Therefore, we conclude that guinea pig platelets have specific surface receptors to C3a and that human platelets appear devoid of receptors to the anaphylatoxin.

  16. In vivo imaging and vibration measurement of Guinea pig cochlea

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Chen, Fangyi; Zheng, Jiefu; Nuttall, Alfred L.; Jacques, Steven L.

    2008-02-01

    An optical coherence tomography (OCT) system was built to acquire in vivo, both images and vibration measurements of the organ of Corti of the guinea pig. The organ of Corti was viewed through a ~500-μm diameter hole in the bony wall of the scala tympani of the first cochlear turn. In imaging mode, the image was acquired as reflectance R(x,z). In vibration mode, the basilar membrane (BM) or reticular lamina (RL) was selected based on the image. Under software control, the system would move the scanning mirrors to bring the sensing volume of the measurement to the desired tissue location. To address the gain stability problem of the homodyne OCT system, arising from the system moving in and out of the quadrature point and also to resolve the 180 degree ambiguity in the phase measurement using an interferometer, a vibration calibration method is developed by adding a vibrating source to the reference arm to monitor the operating point of the interferometric system. Amplitude gain and phase of various cochlear membranes was measured for different sound pressure level (SPL) varying from 65dB SPL to 93 dB SPL.

  17. Antispasmodic effect of 4'-methylepigallocatechin on guinea pig ileum.

    PubMed

    da Rocha, Marcelly Barbosa; Souza, Fábia Valéria Menezes; dos Santos Estevam, Charlez; Pizza, Cosimo; Sant'ana, Antônio Euzébio Goulart; Marçal, Rosilene Moretti

    2012-10-01

    The antispasmodic effect of 4'-methylepigallocatechin (MEC), which was isolated from Maytenus rigida Mart (Celestraceae), was investigated in vitro in guinea pig intestinal segments. In the isolated ileum, MEC (1 nM-100 μM) did not modify the ileal spontaneous tonus or the electrically elicited contractions. MEC (8 μM) significantly (p<0.01) reduced the submaximal contractions induced by histamine (2 μM), carbachol (100 μM) and BaCl₂ (0.03 M). An additive relaxing action (p<0.001) was observed by co-incubation of verapamil (10 nM) and MEC (8 μM). Although MEC (1 nM-100 μM) did not modify the contractions elicited by 60 mM KCl, it significantly reduced the CaCl₂ contractile response without changing the EC₅₀ (effective concentration of CaCl₂ causing 50% of maximum response). In brief, these results show that MEC has a potent ileal spasmolytic effect and blocks spasms induced by specific and nonspecific stimuli. Importantly, the spasmolytic effects were attained at low concentrations and might be related to the symptomatic relief of abdominal pain that is obtained from the use of the M. rigida stem bark. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Experimental microembolism induces localized neuritic pathology in guinea pig cerebrum.

    PubMed

    Li, Jian-Ming; Cai, Yan; Liu, Fei; Yang, La; Hu, Xia; Patrylo, Peter R; Cai, Huaibin; Luo, Xue-Gang; Xiao, Dong; Yan, Xiao-Xin

    2015-05-10

    Microbleeds are a common finding in aged human brains. In Alzheimer's disease (AD), neuritic plaques composed of β-amyloid (Aβ) deposits and dystrophic neurites occur frequently around cerebral vasculature, raising a compelling question as to whether, and if so, how, microvascular abnormality and amyloid/neuritic pathology might be causally related. Here we used a guinea pig model of cerebral microembolism to explore a potential inductive effect of vascular injury on neuritic and amyloid pathogenesis. Brains were examined 7-30 days after experimental microvascular embolization occupying ~0.5% of total cortical area. Compared to sham-operated controls, glial fibrillary acidic protein immunoreactivity was increased in the embolized cerebrum, evidently around intracortical vasculature. Swollen/sprouting neurites exhibiting increased reactivity of nicotinamide adenine dinucleotide phosphate diaphorase, parvalbumin, vesicular glutamate transporter 1 and choline acetyltransferase appeared locally in the embolized brains in proximity to intracortical vasculature. The embolization-induced swollen/sprouting neurites were also robustly immunoreactive for β-amyloid precursor protein and β-secretase-1, the substrate and initiating enzyme for Aβ genesis. These experimental data suggest that microvascular injury can induce multisystem neuritic pathology associated with an enhanced amyloidogenic potential in wild-type mammalian brain.

  19. Acquired chemotactic inhibitors during infection with guinea pig cytomegalovirus.

    PubMed Central

    Tannous, R; Myers, M G

    1983-01-01

    Factors involved in neutrophil and monocyte migrations were serially studied in strain 2 guinea pigs undergoing initial cytomegalovirus infection and sham-inoculated controls. All studies remained unchanged in uninfected animals. Monocyte migrations and neutrophil spontaneous migration remained unchanged in infected animals. However, transient abnormalities occurred early in infection, comprising a decrease in neutrophil-directed migration towards C5-derived chemotactic fractions (C5-fr) and a decrease in the chemotactic activity of zymosan-activated plasma. Consequently, the presence of neutrophil- and chemotaxin-directed inhibitors in plasma was investigated. Normal neutrophils, C5-fr, Escherichia coli-derived bacterial factor, and the synthetic peptide F-met-leu-phe were first incubated with control or infected plasmas and then assayed for directed migration and lysosomal enzyme release. Results indicated the de novo appearance of both neutrophil- and chemotaxin-directed inhibitory activities in plasma during early infection. The neutrophil-directed inhibition was heat stable (56 degrees C for 120 min) and nonspecific (responses to all chemotaxins were inhibited). The chemotaxin-directed inhibition was heat stable and C5-fr specific. The cytomegalovirus-induced inhibitors may be important in the enhanced susceptibility to concurrent opportunistic infections. PMID:6305847

  20. Experimental zinc deficiency in guinea-pigs: biochemical changes.

    PubMed

    Gupta, R P; Verma, P C; Gupta, R K

    1986-05-01

    1. Zinc deficiency was produced experimentally in guinea-pigs fed on a diet containing 1.25 mg Zn/kg diet over a period of 60 d. In addition, the response of the Zn-deficient (ZnD) animals to Zn supplementation was studied for 15 d. 2. In the ZnD group a significant reduction was found in serum Zn and protein concentrations and in alkaline phosphatase (EC 3.1.3.1; AP) activity from day 24 onwards. 3. Paper electrophoretic studies on serum revealed a significant decrease in relative values, as well as absolute values, of albumin and gamma-globulin and an increase in beta-globulin. 4. Albumin:globulin increased on day 24 but decreased significantly from day 48 onwards. 5. The kidney and testis of the ZnD group showed a reduction in Zn and protein contents, and AP activity. 6. Zn supplementation of the previously ZnD group resulted in marked although incomplete improvement in the biochemical indices studied.

  1. [Study of Magnolia grandiflora extracts in guinea pigs cardiac muscle].

    PubMed

    del Valle Mondragón, Leonardo; Tenorio López, Fermín Alejandro; Torres Narváez, Juan Carlos; Zarco Olvera, Gabriela; Pastelín Hernández, Gustavo

    2004-01-01

    Several extracts from diverse Magnolia grandiflora varieties were pharmacological evaluated in the cardiac muscle. From March to July, flowers and leaves from Magnolia grandiflora, native from the National Institute of Cardiology "Ignacio Chávez", from north, west, and orient zones from Mexico City, and from Puebla, Colima and Chiapas states were collected. They were separately processed and the extracts were obtained by maceration with ethanol-water (1:3 v/v) at 4 degrees C during two weeks. Qualitative analysis was accomplished with thin-layer, column and high-performance liquid chromatographies (HPLC). Functional and molecular analysis was made by specific chemical reactivity and by protonic magnetic resonance (RMN 1H). Pharmacological evaluation was completed in isolated and perfused male guinea pigs hearts. Extracts, fractions, and compounds were administrated by serial bolus in a gradual dose-response curves study in which left intraventricular pressure and coronary perfusion pressure were recorded, evaluating by such the positive inotropic and vasodilator effects of Magnolia grandiflora extracts. Vulgarenol and 2-p-hydroxyphenyl-2-hydroxy-ethylamine were isolated and identified, and the obtained results suggest that its positive inotropic and vasodilator effects are owed to these substances, being complemented by magnograndiolide and tyramine.

  2. Surface immunoglobulin of guinea-pig leukaemic lymphocytes.

    PubMed Central

    Stevenson, G T; Eady, R P; Hough, D W; Jurd, R D; Stevenson, F K

    1975-01-01

    The surface immunoglobulin of the transplantable L2C leukaemia of strain 2 guinea-pigs has been investigated. The immunoglobulin is seen to be synthesized when the cells are maintained in culture, indicating its intrinsic origin. Immunolabelling of the cell surface and immunochemical study of the Fab released by limited surface proteolysis indicate the presence of immunoglobulin of class IgM. IgG and free light chains were not detected, and there is unlikely to be an appreciable amount of immunoglobulin of any other class. The amount of immunoglobulin present, in terms of 4-chain monomers, is approximately 100,000 molecules per cell. Its half-life, calculated from the rate of reappearance in vitro of surface Fab after proteolytic clearing, is approximately 5 hours. Immunoglobulin secreted into the environment appears to arise predominantly or entirely from the cell surface: there is no evidence of an appreciable export of immunoglobulin which does not have a surface phase. Papain at 0.06 mg/ml rapidly removes the surface Fab. Residual Fcmu can then be detected by immunofluorescence, suggesting that papain cleaves surface IgM at a hinge region with the molecule in situ on the membrane. The released Fab is only moderately susceptible to degradation by papain at the enzyme: substrate ratio prevailing. It has been possible to isolate it from the papain digest by immuno-adsorption, with a notional yield of 75 mug per 10-10 cells, and then to prepare antisera against it. PMID:48498

  3. Sulfur Mustard Induces Immune Sensitization in Hairless Guinea Pigs

    PubMed Central

    Mishra, Neerad C.; Rir-sima-ah, Jules; March, Thomas; Weber, Waylon; Benson, Janet; Jaramillo, Richard; Seagrave, Jean-Clare; Schultz, Gregory; Grotendorst, Gary; Sopori, Mohan

    2009-01-01

    Sulfur mustard (SM, bis-(2-chloroethyl) sulfide) is a well known chemical warfare agent that may cause long-term debilitating injury. Because of the ease of production and storage, it has a strong potential for chemical terrorism; however, the mechanism by which SM causes chronic tissue damage is essentially unknown. SM is a potent protein alkylating agent, and we tested the possibility that SM modifies cellular antigens, leading to an immunological response to “altered self” and a potential long-term injury. To that end, in this communication, we show that dermal exposure of euthymic hairless guinea pigs induced infiltration of both CD4+ and CD8+ T cells into the SM-exposed skin and strong upregulated expression of proinflammatory cytokines and chemokines (TNF-α, IFN-γ, and IL-8) in distal tissues such as the lung and the lymph nodes. Moreover, we present evidence for the first time that SM induces a specific delayed-type hypersensitivity response that is associated with splenomegaly, lymphadenopathy, and proliferation of cells in these tissues. These results clearly suggest that dermal exposure to SM leads to immune activation, infiltration of T cells into the SM-exposed skin, delayed-type hypersensitivity response, and molecular imprints of inflammation in tissues distal from the site of SM exposure. These immunological responses may contribute to the long-term sequelae of SM toxicity. PMID:19887117

  4. Sulfur mustard induces immune sensitization in hairless guinea pigs.

    PubMed

    Mishra, Neerad C; Rir-sima-ah, Jules; March, Thomas; Weber, Waylon; Benson, Janet; Jaramillo, Richard; Seagrave, Jean-Clare; Schultz, Gregory; Grotendorst, Gary; Sopori, Mohan

    2010-02-01

    Sulfur mustard (SM, bis-(2-chloroethyl) sulfide) is a well known chemical warfare agent that may cause long-term debilitating injury. Because of the ease of production and storage, it has a strong potential for chemical terrorism; however, the mechanism by which SM causes chronic tissue damage is essentially unknown. SM is a potent protein alkylating agent, and we tested the possibility that SM modifies cellular antigens, leading to an immunological response to "altered self" and a potential long-term injury. To that end, in this communication, we show that dermal exposure of euthymic hairless guinea pigs induced infiltration of both CD4(+) and CD8(+) T cells into the SM-exposed skin and strong upregulated expression of proinflammatory cytokines and chemokines (TNF-alpha, IFN-gamma, and IL-8) in distal tissues such as the lung and the lymph nodes. Moreover, we present evidence for the first time that SM induces a specific delayed-type hypersensitivity response that is associated with splenomegaly, lymphadenopathy, and proliferation of cells in these tissues. These results clearly suggest that dermal exposure to SM leads to immune activation, infiltration of T cells into the SM-exposed skin, delayed-type hypersensitivity response, and molecular imprints of inflammation in tissues distal from the site of SM exposure. These immunological responses may contribute to the long-term sequelae of SM toxicity.

  5. Antitussive effect of Carum copticum in guinea pigs.

    PubMed

    Boskabady, M H; Jandaghi, P; Kiani, S; Hasanzadeh, L

    2005-02-10

    Several therapeutic effects including anti-asthma and dyspnea have been described for the seeds of Carum copticum In previous studies the relaxant and anticholinergic (functional antagonism) effects, histamine (H(1)) inhibitory effect of Carum copticum have been demonstrated on guinea pig tracheal chains. In the present study the antitussive effect of this plant was evaluated. The antitussive effects of aerosols of two different concentrations of aqueous and macerated extracts and carvacrol, codeine, and saline were tested by counting the number of coughs produced due to aerosol of citric acid 10 min after exposing animals to aerosols of different solutions (for carvacrol n=5 and for other solutions n=6). The results showed significant reduction of cough number obtained in the presence of both concentrations of aqueous and macerated extracts and codeine (p<0.001 for extracts and p<0.01 for codeine). The cough number obtained in the presence of higher concentration of aqueous and macerated extracts was significantly less than those of lower concentrations (p<0.05 for both extracts). In addition the cough number obtained in the presence of both concentrations of aqueous and macerated extracts was significantly lower than that of codeine (p<0.05 to 0.001). However, carvacrol did not show any antitussive effect. These results indicated an antitussive effect of Carum copticum which was even greater than that of codeine at concentrations used. In addition the antitussive effect of Carum copticum was not due to its main constituent, carvacrol.

  6. Superoxide Production by Digitonin-Stimulated Guinea Pig Granulocytes

    PubMed Central

    Cohen, Harvey J.; Chovaniec, Margaret E.

    1978-01-01

    N-ethylmaleimide, divalent cations, ethylene glycol bis (β aminoethyl ether) N,N,N′,N′,-tetraacetate, 2-deoxyglucose, cyanide, and dinitrophenol were examined for their effect on the ability of guinea pig granulocytes to generate superoxide (O2−) when stimulated by digitonin. N-ethylmaleimide (1 mM) inhibits only when added before complete activation of the O2− generating system, and at lower concentrations (0.05-0.2 mM) slows the activation process. Ca++ is required for maximum O2− generation, and Mg++ decreases the amount of Ca++ required. Ethylene glycol bis (β aminoethyl ether) N,N,N′,N′,-tetraacetate (10 mM) inhibits only if added before complete activation. Incubation of cells in 2-DOG causes a time- and concentration-dependent inhibition of O2− generation. It also increases the time required for activation of this system. Cyanide and dinitrophenol increase the rate of O2− production. However, when these compounds are added to cells whose O2− production is partially inhibited by incubation in 2-deoxyglucose, complete inhibition results. If cyanide or dinitrophenol is added after activation of 2-deoxyglucose-treated cells, no further inhibition occurs. On the basis of the above results, we conclude that the activation of the O2− generating system is N-ethylmaleimide sensitive, Ca++ dependent, and energy requiring, but that the activity of the enzyme system in the cell is not. PMID:207722

  7. Epidermal cell proliferation in guinea pigs with experimental dermatophytosis

    SciTech Connect

    Tagami, H.

    1985-08-01

    To elucidate the mechanisms underlying the self-healing process of experimental dermatophytosis produced in guinea pigs by an occlusive method with Trichophyton mentagrophytes, epidermal proliferative activity was evaluated by the in vivo tritiated thymidine-labeling technique performed at various intervals after the first and second infections. Determination of labeling indices disclosed that an increased epidermal proliferation correlated well with the severity of inflammatory changes, i.e., a peak activity was noted after 10 days in primary infection and at 2 days in reinfection, respectively, and was followed by subsequent spontaneous lesion clearance after 10 days. Application of a heat-killed spore suspension produced inflammatory changes with enhanced epidermopoiesis, similar to those induced by reinoculation of living spores, only in immune animals. The present results indicate that the dermatitic changes occurring in experimental dermatophytosis increase epidermopoiesis which facilitates elimination of the fungus from the stratum corneum and that host immune activity, particularly contact sensitivity to fungal antigen, exerts a crucial role to induce these changes.

  8. Low protein diets improve survival from peritonitis in guinea pigs.

    PubMed Central

    Peck, M D; Alexander, J W; Gonce, S J; Miskell, P W

    1989-01-01

    Enteral diets with different protein content were tested to determine their effect on outcome in a model of protracted bacterial peritonitis. Hartley guinea pigs were provided with gastrostomies, and 1 week later, osmotic pumps were implanted into the peritoneal cavity to allow for continuous release of live bacteria over the course of 1 week. Three days after pump implantation, the animals began receiving isocaloric enteral diets that contained 5%, 10%, 15%, or 20% of total calories as protein. After 2 weeks of observation, the survivors were killed. All animals lost weight during the 2-weeks period, but there was no difference in weight lost. Nitrogen balance correlated with dietary protein. The mortality rate was significantly higher in the groups that received 15% and 20% of total calories compared with the group that received 5% (p less than 0.05). Although dietary protein in the 5% group was insufficient for meeting the nutritional needs of the animal, survival was best in this group. Possible explanations are that protein restriction in this model may either augment host defence or impair bacterial virulence. PMID:2494959

  9. Experimental microembolism induces localized neuritic pathology in guinea pig cerebrum

    PubMed Central

    Li, Jian-Ming; Cai, Yan; Liu, Fei; Yang, La; Hu, Xia; Patrylo, Peter R.; Cai, Huaibin; Luo, Xue-Gang; Xiao, Dong; Yan, Xiao-Xin

    2015-01-01

    Microbleeds are a common finding in aged human brains. In Alzheimer's disease (AD), neuritic plaques composed of β-amyloid (Aβ) deposits and dystrophic neurites occur frequently around cerebral vasculature, raising a compelling question as to whether, and if so, how, microvascular abnormality and amyloid/neuritic pathology might be causally related. Here we used a guinea pig model of cerebral microembolism to explore a potential inductive effect of vascular injury on neuritic and amyloid pathogenesis. Brains were examined 7-30 days after experimental microvascular embolization occupying ~0.5% of total cortical area. Compared to sham-operated controls, glial fibrillary acidic protein immunoreactivity was increased in the embolized cerebrum, evidently around intracortical vasculature. Swollen/sprouting neurites exhibiting increased reactivity of nicotinamide adenine dinucleotide phosphate diaphorase, parvalbumin, vesicular glutamate transporter 1 and choline acetyltransferase appeared locally in the embolized brains in proximity to intracortical vasculature. The embolization-induced swollen/sprouting neurites were also robustly immunoreactive for β-amyloid precursor protein and β-secretase-1, the substrate and initiating enzyme for Aβ genesis. These experimental data suggest that microvascular injury can induce multisystem neuritic pathology associated with an enhanced amyloidogenic potential in wild-type mammalian brain. PMID:25871402

  10. Dendrodendritic connections between the cochlear efferent neurons in guinea pig.

    PubMed

    Szabó, Zs; Bácskai, T; Deák, Á; Matesz, K; Veress, G; Sziklai, I

    2011-10-31

    The outer hair cells of organ of Corti are innervated by the efferent neurons of medial olivocochlear neurons (MOC) of the brainstem which modify the cochlear auditory processing and sensitivity. Most of the MOC neurons are excited by a dominant ear and only a small portion of them is excited by both ears resulting in a binaural facilitation. The functional role of the feedback system between the organ of Corti and the cochlear efferent neurons is the protection of the ear from acoustic injury. The rapid impulse propagation in the bilateral olivocochlear system is suggestive of an electrotonic interaction between the bilateral olivocochlear neurons. The morphological background of the MOC pathway is not yet completely characterized. Therefore, we have labeled the bilateral cochlear nerves with different neuronal tracers in guinea pigs. In the anesthetized animals the cochlear nerves were exposed in the basal part of the modiolus and labeled simultaneously with different retrograde fluorescent tracers. By using confocal laser scanning microscope we could detect close appositions between the dendrites of the neurons of bilateral MOC. The distance between the neighboring profiles suggested close membrane appositions without interposing glial elements. These connections might serve as one of the underlying mechanisms of the binaural facilitation mediated by the olivocochlear system. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Macrominerals in guinea pig milk during 21 days of lactation.

    PubMed

    Anderson, R R; Sheffield, L G

    1988-02-01

    Milk samples were obtained daily from English short-hair albino guinea pigs for 21 d. Analyses included six macrominerals: Ca, P, K, chloride, Na, and Mg (in order of decreasing concentration). All minerals except K gradually increased in concentration from the beginning to the end of lactation. Calcium concentration began at 38 mM on d 1 and was 78 mM on d 21. The pattern of increase was quadratic: Y (mM) = 39 -.48X (day of lactation) + .11 X2. Phosphorus concentration was 38 mM on d 1 and highest at 51 mM on d 21. Chloride was 19 mM on d 1 and 68 mM on d 21. Sodium was 13 mM on d 1 and highest at 42 mM on d 21. Magnesium was 11 mM on d 1 and was highest on d 18 (13 mM). However, K was 31 mM on d 1, reached a high of 33 mM on d 3, and was lowest on d 19 (12 mM). These changes in concentration and previously reported volume changes suggest alterations in functional capacities of ionic transport mechanisms of secretory cell membranes in this species.

  12. Comparison of guinea pig and protozoan models for determining virulence of Legionella species.

    PubMed Central

    Fields, B S; Barbaree, J M; Shotts, E B; Feeley, J C; Morrill, W E; Sanden, G N; Dykstra, M J

    1986-01-01

    Legionella pneumophila organisms are able to infect and multiply within the ciliated protozoan Tetrahymena pyriformis. This ability may be associated with virulence, because an attenuated strain of L. pneumophila fails to multiply within this protozoan, whereas a virulent strain increases 10,000-fold in number when coincubated with T. pyriformis. Seventeen strains (11 species) of legionellae were evaluated for virulence by intraperitoneal injection of guinea pigs and inoculation of protozoan cultures. Analysis of the data indicates that there are four categories of legionellae with respect to virulence as follows: organisms that infect and kill guinea pigs and multiply in T. pyriformis; organisms that infect but do not kill guinea pigs and multiply in T. pyriformis; organisms that do not infect guinea pigs but are lethal at high concentrations and multiply in T. pyriformis; and organisms that neither infect nor kill guinea pigs and fail to multiply in T. pyriformis. Evidence suggests that these distinctions are based on two virulence factors: intracellular multiplication in a host and toxic activity. Images PMID:3744550

  13. Stereoselective pharmacokinetics of cetirizine in the guinea pig: role of protein binding.

    PubMed

    Gupta, Anubha; Hammarlund-Udenaes, Margareta; Chatelain, Pierre; Massingham, Roy; Jonsson, E Niclas

    2006-09-01

    To characterize the pharmacokinetics of cetirizine enantiomers in the guinea pig including protein binding in both the guinea pig and human plasma. Plasma concentrations of cetirizine enantiomers in the guinea pig were determined using a LC-MS/MS method after a short i.v. infusion (1, 2 and 4 mg/kg) of racemic cetirizine. Protein binding was determined using an in vitro equilibrium dialysis technique. A pharmacokinetic model was developed using NONMEM and the differences in pharmacokinetic parameters of levocetirizine and dextrocetirizine were estimated. The plasma concentration time data of both the enantiomers were best described by a three-compartment pharmacokinetics model. The clearance (CL) of levocetirizine and dextrocetirizine was 1.2 and 2.7 ml/min, respectively, and the volume of distribution at steady state (Vss) was 457 ml and 996 ml, respectively. The fraction unbound (fu) in guinea pig plasma for levocetirizine and dextrocetirizine was 7-10% and 16-21% while in human plasma, it was 8% and 12%, respectively. The factor describing the difference in the pharmacokinetic parameters of the cetirizine enantiomers was estimated to be 2.26. Cetirizine pharmacokinetics is stereoselective in the guinea pig. For levocetirizine, fu, CL and Vss were half those of dextrocetirizine, indicating that protein binding is an important factor affecting the pharmacokinetics of cetirizine. The effect of protein binding on the pharmacokinetics of the cetirizine enantiomers could be extrapolated to humans. Copyright 2006 John Wiley & Sons, Ltd.

  14. Tachykinins activate guinea-pig alveolar macrophages: involvement of NK2 and NK1 receptors.

    PubMed Central

    Brunelleschi, S.; Vanni, L.; Ledda, F.; Giotti, A.; Maggi, C. A.; Fantozzi, R.

    1990-01-01

    1. The effects of substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) were evaluated on superoxide anion (O2-.) production by guinea-pig alveolar macrophages (AM). 2. SP dose-dependently (ED50 = 0.7 nM) evoked O2-. production from guinea-pig AM; the N-terminal heptapeptide, SP(1-7), was ineffective. In the presence of thiorphan (10(-5) M), an enkephalinase inhibitor, the stimulating effects of SP were not significantly modified. NKA and NKB were both able to induce O2-. production from guinea-pig AM, ED50 values being 0.1 and 1.3 nM, respectively. Therefore, the rank order of activity of natural tachykinins was NKA greater than SP greater than NKB. Tachykinin-evoked effects were quantitatively similar to those elicited by the autacoid mediator PAF-acether and less than those induced by the synthetic peptide N-formylmethionyl-leucyl-phenylalanine (FMLP). 3. The NK2 receptor agonist [beta-Ala8]-NKA (4-10) dose-dependently evoked O2-. production from guinea-pig AM; the NK1 receptor agonist [Pro9]-SP sulphone acted only at high concentrations, while the NK3 receptor agonist [Me,Phe7]-NKB was ineffective. 4. These findings indicate that guinea-pig AM possess NK2 and possibly some NK1 tachykinin receptors and further suggest tachykinin involvement in lung pathophysiology. PMID:1697194

  15. Breathing responses of unanesthetized man and guinea pigs to increased transrespiratory pressure.

    PubMed

    Gillespie, J R; Bruce, E; Alexander, J; Mead, J

    1979-07-01

    We compared the breathing responses of unanesthetized men and guinea pigs to externally imposed shifts in lung volume produced by steady pressures applied to the body surface while the mouth remained near atmospheric pressure. Lung inflation caused no consistent or significant changes either in frequency or end-tidal CO2 in the three men. In contrast, during lung inflation the guinea pigs breathed at low frequencies and smaller tidal volumes and showed consistent increases in arterial PCO2 lasting up to 10 min. The changes seen immediately on application of pressure, namely apneic periods followed by breathing in which inspiratory duration was shortened while expiratory duration was substantially increased, indicates that conscious guinea pigs have active inflation reflexes. We concluded that the reflex responses rather than mechanical factors probably account for the underventilation in the guinea pigs and that guinea pigs are not nearly as well equipped as is man to defend gas exchange in the face of nonmetabolic shifts in lung volume.

  16. Incorporation of intravenously injected albumin, immunoglobulin G, and fibrinogen in guinea pig megakaryocyte granules.

    PubMed Central

    Handagama, P J; Shuman, M A; Bainton, D F

    1989-01-01

    In a previous study we provide evidence for a circuitous pathway by which circulating plasma proteins enter megakaryocyte granules by an endocytic mechanism and are returned to the circulation in platelets (1987. Proc. Natl. Acad. Sci. USA. 84:861-865). Horseradish peroxidase (40,000 mol wt) was injected into guinea pigs and its uptake into megakaryocyte organelles examined by electron microscopy and cytochemistry. In the present study we tested the ability of guinea pig megakaryocytes to take up intravenously injected albumin, IgG, and fibrinogen. We used two types of proteins to study the endocytic pathway: (a) heterologous human proteins, which were detected immunohistochemically using antibodies that do not crossreact with the native guinea pig counterparts; and (b) human and guinea pig proteins labeled with the small (250 mol wt), inert molecule, biotin, which were detected using an antibody against biotin. We detected all three of the injected proteins in bone marrow megakaryocytes in patterns identical to those of native counterparts. The injected protein consistently appeared in platelets 24 h later and was secreted in response to thrombin. We conclude that there are at least two mechanisms by which guinea pig megakaryocyte granules acquire proteins (a) endogenous synthesis, as demonstrated by others, and (b) endocytosis of plasma proteins synthesized by other types of cells. Images PMID:2738161

  17. Modeling the Disease Course of Zaire ebolavirus Infection in the Outbred Guinea Pig.

    PubMed

    Cross, Robert W; Fenton, Karla A; Geisbert, Joan B; Mire, Chad E; Geisbert, Thomas W

    2015-10-01

    Rodent models that accurately reflect human filovirus infection are needed as early screens for medical countermeasures. Prior work in rodents with the Zaire species of Ebola virus (ZEBOV) primarily used inbred mice and guinea pigs to model disease. However, these inbred species do not show some of the important features of primate ZEBOV infection, most notably, coagulation abnormalities. Thirty-six outbred guinea pigs were infected with guinea pig-adapted ZEBOV and examined sequentially over an 8-day period to investigate the pathologic events that lead to death. Features of disease in ZEBOV-infected outbred guinea pigs were largely consistent with disease in humans and nonhuman primates and included early infection of macrophages and dendritiform cells, apoptosis of bystander lymphocytes, and increases in levels of proinflammatory cytokines. Most importantly, dysregulation of circulating levels of fibrinogen, protein C activity, and antifibrinolytic proteins and deposition of fibrin in tissues demonstrated both biochemical and microscopic evidence of disseminated intravascular coagulation. These findings suggest that the outbred guinea pig model recapitulates ZEBOV infection of primates better than inbred rodent models, is useful for dissecting key events in the pathogenesis of ZEBOV, and is useful for evaluating candidate interventions prior to assessment in primates. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. [Delayed hypersensitivity after anthrax vaccination. I--Study of guinea pigs vaccinated against anthrax].

    PubMed

    Shlyakhov, E; Rubinstein, E

    1994-01-01

    To evaluate delayed hypersensitivity after anthrax vaccination, an Anthraxin skin test was performed in 682 guinea pigs at various times after immunization with veterinary unencapsulated active anthrax vaccine. Results were compared with those obtained in unimmunized control guinea pigs (n = 216), in guinea pigs that received a non-immunizing dose of live vaccine (n = 183) and in guinea pigs inoculated with inactivated vaccine (n = 120). Anthraxin skin tests were positive in the first postvaccination days. The incidence and intensity of positive tests peaked between two weeks and one month after vaccination and then gradually decreased during the first year. Study of resistance of guinea pigs to an inoculum at a lethal dose of a virulent strain of Bacillus anthracis showed a close correlation between positive tests and resistance. These findings demonstrate development of cell-mediated immunity after anthrax vaccination. The Anthraxin skin test should have practical applications for the production of vaccines and for evaluation of the immune status of vaccinated livestock [corrected].

  19. [Isobutane driven salbutamol sulfate metered dose inhaler: formulation selection and respiratory tract absorption in guinea pigs].

    PubMed

    Ding, Li; Zhang, Jun-Shou

    2009-09-01

    This paper is to study the iso-butane (A-31)-driven salbutamol sulfate (SS) metered dose inhaler (MDI) formulations and inhaling status in guinea pigs. Solubility determination and orthogonal design were used to screen non-chlorofluorocarbon (CFC) SS MDI formulations. Intubation inhalation of MDI in guinea pigs was used as a main administration method. Fluorescence HPLC detection method was testified as a potential method in assaying the concentration of SS in plasma of guinea pigs after inhaling various SS MDI formulations. Analysis of the data was executed with statistical moment calculation from which pharmacokinetic parameters were obtained. The results show that A-31 based on SS MDI formulations were screened and the guinea pigs in vivo determination method after inhaling SS MDI was established. The zero-moment rations of SS/A-31 MDI formulation to contrast sample and CFC SS MDI was 143.26% and 147.01%, respectively. The first moment value of SS/A-31 MDI formulation was the highest. It is a preliminary conclusion that the absorption result of SS/A-31 MDI formulation inhaled by guinea pigs is equivalent to HFA-134a formulation in sale and better than CFC formulation. A-31 could be used as a potential substitute candidate for CFC MDI propellant.

  20. Reduced noise susceptibility in littermate offspring from heterozygous animals of the German waltzing guinea pig.

    PubMed

    Skjönsberg, Åsa; Mannström, Paula

    2015-07-08

    The German waltzing guinea pig is a spontaneously mutated strain with severe auditory and vestibular impairment caused by a so far unknown genetic mutation. The animals are born deaf and show a circling behavior. The heterozygote animals of this guinea pig strain have functionally normal hearing and balance. However, these animals have, in earlier studies, shown an increased resistance to noise compared with normal wild-type guinea pigs. In the present study, we explored the functional hearing with auditory brainstem response thresholds before and at different time points after noise exposure. Symptom-free littermates from heterozygote couples of the German waltzing guinea pigs were exclusively used for the study, which, after the hearing test, were sent back for breeding to confirm their genotype (i.e. heterozygote or normal). The aim of this paper was to ascertain that the previously shown reduced susceptibility to noise trauma in the heterozygote animals of the German waltzing guinea pig was also evident when littermates were used as control animals. The findings are important for further analysis of the heterozygote animals of this strain and for future investigations of the underlying mechanisms behind the diverse susceptibility to exposures of loud sound.

  1. Late effects of radiation on the lumbar spinal cord of guinea pigs: Re-treatment tolerance

    SciTech Connect

    Mason, K.A. ); Withers, H.R.; Chiang, Chi-Shiun )

    1993-07-15

    Using a guinea pig model of lumbar myelopathy, various factors affecting the tolerance of spinal cord to irradiation were assessed: (a) extent of initial injury; (b) time interval between priming and test doses; and (c) animal age at the time of initial radiation treatment. A 3 cm section of lumbar spinal cord of guinea pigs was irradiated with fractionated doses of 4.5 Gy gamma rays given as 9 fractions per week. Guinea pigs were primed with 9 x 4.5 Gy in 7 days which is 60% of the ED[sub 50] for a continuous course of treatment. After 28 or 40 weeks, animal were retreated with 6-14 fractions of 4.5 Gy. Animals were observed for 2 years following the priming dose and both the incidence and latency of myelopathy recorded. Young adult guinea pigs (8 wk old) showed both a decreased radiation tolerance and latency compared to old individuals (40 wk old). At 28 or 40 wk after 9 x 4.5 Gy, only about 8% of the initial injury was remembered in young adult guinea pigs. The amount of residual injury was dependent on the initial damage as a proportion of the tolerance dose. The spinal cord shows a greater capacity for long-term recovery than generally appreciated and re-treatment doses clinically prescribed may be lower than necessary. 8 refs., 3 figs., 2 tabs.

  2. Expression of matrix metalloproteinases and ovarian morphological changes in androgenized cyclic female guinea pigs.

    PubMed

    Li, Jun-rong; Shen, Ting; Wang, Yan-li; Wei, Quan-wei; Shi, Fang-xiong

    2016-02-01

    This study was conducted to investigate expression of matrix metalloproteinases (MMPs) and ovarian morphological changes in androgenized cyclic female guinea pigs. Adult cyclic female guinea pigs were injected daily for 28 days with medium doses of testosterone propionate (TP; 1 mg/100g), high doses of TP (2 mg/100g), or saline (control). Serum concentrations of testosterone, estradiol (E2), and progesterone (P4) were measured. Histologic sections of ovaries were stained with hematoxylin-eosin and by immunohistochemistry. Expressions of steroidogenic acute regulatory protein, proliferating cell nuclear antigen, and MMP-2 and MMP-9 in the ovary were characterized by immunohistochemistry. After 28 days of TP injection, serum testosterone concentrations were increased dose-dependently. An appropriate dosage of TP could induce permanent anovulation in guinea pigs, making them a potential model for human polycystic ovary syndrome. MMP-2 and MMP-9 are jointly involved in the growth and atresia of ovarian follicles in cyclic guinea pigs. Increased numbers of atretic antral follicles in the ovary might be associated with the observed high expression of MMP-2 in androgenized cyclic guinea pigs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A guinea pig model of hypersensitivity to allergenic fractions of natural rubber latex.

    PubMed

    Aamir, R; Safadi, G S; Mandelik, J; Cornish, K; Melton, A L; Pien, L C; Wagner, W O; Battisto, J R

    1996-06-01

    Allergy to natural rubber latex is a growing medical problem with life-threatening aspects. The aim of this study was to learn if guinea pigs could serve as a suitable model for immediate-type hypersensitivity to latex. Guinea pigs were immunized either with whole non-ammoniated latex extract, or with one of nine SDS-PAGE-separated components. Other animals were injected with electroeluted latex components localized on gel at 14, 24 and a cluster around 45 kD. Before and after immunization, sera from the animals were examined by ELISA, immunoblots, passive cutaneous anaphylaxis (PCA) and passive systemic anaphylaxis. Latex-specific antibodies were detected by ELISA and immunoblots in sera from all immunized animals. PCA assays showed that the guinea pigs had homocytotropic antibodies dilutable to 1:250. PCA was abolished when sera from animals immunized with allergens in alum were heated at 56 degrees C for 30 min indicating the antibodies were of the E isotype. Passive systemic anaphylaxis was induced in 4 of 10 guinea pigs. The results show that guinea pigs are capable of making antibodies to latex protein components that mediate dermal and systemic anaphylaxis, paralleling the spectrum of clinical and laboratory findings of humans with immediate-type clinical latex hypersensitivity.

  4. Isolation and characterization of guinea-pig serum amyloid P component.

    PubMed Central

    Maudsley, S; Hind, C R; Munn, E A; Buttress, N; Pepys, M B

    1986-01-01

    A pentraxin was isolated from acute-phase guinea-pig serum by calcium-dependent affinity chromatography on agarose. It was immunochemically identical to guinea-pig amyloid P component and therefore has been called guinea-pig serum amyloid P component (SAP). Guinea-pig SAP has an apparent MW of between 265,000 and 300,000 by different techniques, and is composed of 10 noncovalently associated subunits arranged in two pentameric annular discs interacting face-to-face. It is apparently composed of two types of subunit, which run as a closely spaced doublet on reduced sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). At least one type of subunit is glycosylated. The serum concentration was 16 +/- 4 mg/l in outbred animals, rising to 25 +/- 4 mg/l in an acute-phase response. Binding to agarose correlated with the agarose pyruvate content and was completely abolished by diazomethane treatment of the agarose, which methylates the pyruvate carboxylic moiety. Binding was also inhibited in the presence of free methyl 4,6-o-(carboxyethylidine)-beta-D-galactopyranoside. No protein resembling C-reactive protein (CRP) was obtained by calcium-dependent affinity chromatography of acute-phase guinea-pig serum on phosphorylcholine (PC)-Sepharose, and it not clear whether a counterpart of CRP exists in this species. Images Figure 1 Figure 2 PMID:3770806

  5. A protease-like permeability factor in guinea pig skin: immunologic identity with plasma Hageman factor.

    PubMed Central

    Yamamoto, T.; Cochrane, C. G.

    1982-01-01

    Vascular permeability enhancement activity of the protease-like permeability factor derived from guinea pig skin and of active guinea pig Hageman factor (beta HFa) were both inhibited by anti-guinea pig Hageman factor rabbit F(ab')2 antibody. The permeability activity of both factors was also absorbed on anti-Hageman factor F(ab')2-Sepharose beads. The latent form of the permeability factor derived from skin extracts produced a single immunoprecipitation line with anti-Hageman factor and gave a reaction of identity with a precipitation band developing between purified Hageman factor and anti-Hageman factor. The latent permeability factor in the fraction corrected the clotting activity of Hageman-factor-deficient human plasma. The clotting activity was also blocked by anti-Hageman factor F(ab')2 antibody. From these results, it was concluded that the skin permeability factor was immunologically and functionally indistinguishable from Hageman factor of plasma. Extracts were obtained from skin of guinea pigs given intravenous injections of 125I-guinea pig Hageman factor immediately before sacrifice to calculate the amount of Hageman factor in the extravascular tissue space of the skin. The pseudoglobulin fractions of the extracts containing a concentration of Hageman factor of approximately 9 microgram of Hageman factor per gram of skin. This was determined both by immunologic means and procoagulant activity. Only 4% of the Hageman factor in the extract was obtained from the intravascular plasma volume of the skin. Images Figure 1 PMID:7044129

  6. The guinea pig as an animal model for developmental and reproductive toxicology studies.

    PubMed

    Rocca, Meredith S; Wehner, Nancy G

    2009-04-01

    Regulatory guidelines for developmental and reproductive toxicology (DART) studies require selection of "relevant" animal models as determined by kinetic, pharmacological, and toxicological data. Traditionally, rats, mice, and rabbits are the preferred animal models for these studies. However, for test articles that are pharmacologically inactive in the traditional animal models, the guinea pig may be a viable option. This choice should not be made lightly, as guinea pigs have many disadvantages compared to the traditional species, including limited historical control data, variability in pregnancy rates, small and variable litter size, long gestation, relative maturity at birth, and difficulty in dosing and breeding. This report describes methods for using guinea pigs in DART studies and provides results of positive and negative controls. Standard study designs and animal husbandry methods were modified to allow mating on the postpartum estrus in fertility studies and were used for producing cohorts of pregnant females for developmental studies. A positive control study with the pregnancy-disrupting agent mifepristone resulted in the anticipated failure of embryo implantation and supported the use of the guinea pig model. Control data for reproductive endpoints collected from 5 studies are presented. In cases where the traditional animal models are not relevant, the guinea pig can be used successfully for DART studies. (c) 2009 Wiley-Liss, Inc.

  7. Inhibition of converting enzyme and neointima formation after vascular injury in rabbits and guinea pigs.

    PubMed

    Clozel, J P; Hess, P; Michael, C; Schietinger, K; Baumgartner, H R

    1991-10-01

    Recently, it has been shown that cilazapril could suppress neointima formation after vascular injury in rats. The goal of the present study was to confirm these findings in guinea pigs and rabbits. Vascular injury was produced by ballooning the right carotid artery of guinea pigs and the right iliac artery of rabbits. The animals were treated with either placebo or cilazapril (30 mg/kg/day and 3 mg/kg/day in guinea pigs and rabbits, respectively). Cilazapril decreased by 42% (p less than 0.001) the neointima area in the guinea pig but was ineffective in rabbits. However, in rabbits, doses of cilazapril higher than 3 mg/kg could not be given because of known toxicological effects in the rabbit. We conclude that the protective effect of cilazapril described in rats also is observed in guinea pigs. However, in rabbits, the maximal tolerated dose of cilazapril was ineffective. These results underline the importance of ongoing clinical studies to evaluate if, in humans, cilazapril inhibits restenosis after coronary angioplasty.

  8. Prevalence and zoonotic risks of Trichophyton mentagrophytes and Cheyletiella spp. in guinea pigs and rabbits in Dutch pet shops.

    PubMed

    Overgaauw, P A M; Avermaete, K H A van; Mertens, C A R M; Meijer, M; Schoemaker, N J

    2017-06-01

    Young rabbits and guinea pigs are often purchased as pets for children and may be infected with zoonotic skin infections. To assess the risk of acquiring such an infection from rabbits or guinea pigs, this study investigated the prevalence of the fungus Trichophyton mentagrophytes and the fur mite Cheyletiella parasitovorax in asymptomatic rabbits and guinea pigs in Dutch pet shops. In 91 pet shops a total of 213 rabbits and 179 guinea pigs were sampled using the Mackenzie technique and cultured. Clean cultures were examined microscopically and a PCR was performed on at least one sample from each pet shop. All animals were investigated for fur mite using a flea comb, a magnifying glass and white paper. From the fur of 3.8% (8/213) of the rabbits and 16.8% (30/179) of the guinea pigs, T. mentagrophytes was isolated. From 1 guinea pig (0,6%) Chrysosporium keratinophilum was isolated. Dermatophyte-positive rabbits and guinea pigs originated from 5.6% (5/90) and 27.3% (24/88) of the investigated pet shops, respectively. Fur mites were not found. Pet shops can play an important role in preventing transmission of zoonotic ringworm infections (dermatophytosis) and educating their customers. Specific preventive measures such as routine screening examinations and (prophylactic) treatment of rabbits and guinea pigs are recommended next to regular hygiene when handling animals. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Understanding the anatomy of ears from guinea pigs and rats and its use in basic otologic research.

    PubMed

    Albuquerque, Agnes Afrodite Sumarelli; Rossato, Maria; Oliveira, José Antonio Apparecido de; Hyppolito, Miguel Angelo

    2009-01-01

    The use of animal samples is important in otologic research and understanding the anatomy of their ears help make proper use of them in research projects. to study guinea pig's and rat's ears under light microscopy(LM) and scanning electron microscopy(SEM) and understand their anatomical advantages in basic otologic research. The temporal bones, tympanic bullas and cochleas from three albino guinea pigs and rats were photographed and analyzed under LM and SEM. Rats aren't as simple to handle as guinea pigs, and often present with otitis media. Rats have a fragile junction of the tympanic bulla, two and half turns in the cochlea, and their tympanic membranes do not seal off the entire external auditory canal. Guinea pigs have full bullas, their incus and malleus are fused and they have three and half cochlear turns. Under SEM, guinea pigs and rats have Tectori Membrane, Raissner's Membrane and the Organ of Corti. Only guinea pigs have Hensen's Cells. Guinea pigs were considered easy to handle for microdissection purposes because of the size and robustness of their temporal bones, and for surgical experiments involving the stapes, the oval window and the tympanic membrane. Under SEM there are similarities guinea pigs and rats, and both can be used in inner ear studies.

  10. Microangioarchitecture of the guinea pig gallbladder and bile duct as studied by scanning electron microscopy of vascular corrosion casts.

    PubMed Central

    Aharinejad, S; Lametschwandtner, A

    1992-01-01

    The microvasculature of the gallbladder, the common bile duct, and the duodenal papilla was investigated in 20 albino guinea pigs (Cavia porcellus) using microvascular corrosion casting and scanning electron microscopy (SEM). Main supplying and draining vessels (first-order vessels) approach the gallbladder along the cystic duct. From the latter, penetrating vessels (second-order vessels) arise which pierce the muscular coat of the gallbladder body to form the plexus of third-order vessels between the muscle coat and the mucosa. Third-order vessels finally branch to supply the subepithelial capillaries, which show a honeycomb arrangement, corresponding to the gallbladder pits. At the areas bordering mucosal pits and beneath the tunicae plicae mucosae, the capillaries form glomera. These structures make the mucosal vasculature suitable for adapting to gallbladder wall distension caused by volume changes. The mucosal capillary glomera may also be involved in absorption of substances from bile, or they could act as buffer zones, counteracting the pressure which develops as the gallbladder volume increases. Venous sphincters occurring at the junction of mucosal vessels with the subjacent third-order veins may regulate blood flow in the mucosal glomera. The neck region as well as bile ducts consist of 2 vascular layers: an inner capillary layer and an outer one containing arterioles and venules. The duodenal papilla has a hemispheric shape and is interposed in the transition zone between the stomach and the duodenum. On the most luminal aspect, the capillaries of the papilla have a ring-shaped arrangement, as do the capillaries of the stomach, surrounding the mucosal glands; the remainder of the papilla is covered by duodenal villi capillaries. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 PMID:1294573

  11. Chlamydial Variants Differ in Ability To Ascend the Genital Tract in the Guinea Pig Model of Chlamydial Genital Infection

    PubMed Central

    Yeruva, Laxmi; Bowlin, Anne K.; Spencer, Nicole; Maurelli, Anthony T.

    2015-01-01

    An important question in the study of chlamydial genital tract disease is why some women develop severe upper tract disease while others have mild or even “silent” infections with or without pathology. Animal studies suggest that the pathological outcome of an infection is dependent upon both the composition of the infecting chlamydial population and the genotype of the host, along with host physiological effects, such as the cyclical production of reproductive hormones and even the size of the infecting inoculum or the number of repeated infections. In this study, we compared two variants of Chlamydia caviae, contrasting in virulence, with respect to their abilities to ascend the guinea pig genital tract. We then determined the effect of combining the two variants on the course of infection and on the bacterial loads of the two variants in the genital tract. Although the variants individually had similar infection kinetics in the cervix, SP6, the virulent variant, could be isolated from the oviducts more often and in greater numbers than the attenuated variant, AZ2. SP6 also elicited higher levels of interleukin 8 (IL-8) in the lower genital tract and increased leukocyte infiltration in the cervix and uterus compared to AZ2. When the two variants were combined in a mixed infection, SP6 outcompeted AZ2 in the lower genital tract; however, AZ2 was able to ascend the genital tract as readily as SP6. These data suggest that the ability of SP6 to elicit an inflammatory response in the lower genital tract facilitates the spread of both variants to the oviducts. PMID:26015484

  12. Replication and Transmission of the Novel Bovine Influenza D Virus in a Guinea Pig Model.

    PubMed

    Sreenivasan, Chithra; Thomas, Milton; Sheng, Zizhang; Hause, Ben M; Collin, Emily A; Knudsen, David E B; Pillatzki, Angela; Nelson, Eric; Wang, Dan; Kaushik, Radhey S; Li, Feng

    2015-12-01

    Influenza D virus (FLUDV) is a novel influenza virus that infects cattle and swine. The goal of this study was to investigate the replication and transmission of bovine FLUDV in guinea pigs. Following direct intranasal inoculation of animals, the virus was detected in nasal washes of infected animals during the first 7 days postinfection. High viral titers were obtained from nasal turbinates and lung tissues of directly inoculated animals. Further, bovine FLUDV was able to transmit from the infected guinea pigs to sentinel animals by means of contact and not by aerosol dissemination under the experimental conditions tested in this study. Despite exhibiting no clinical signs, infected guinea pigs developed seroconversion and the viral antigen was detected in lungs of animals by immunohistochemistry. The observation that bovine FLUDV replicated in the respiratory tract of guinea pigs was similar to observations described previously in studies of gnotobiotic calves and pigs experimentally infected with bovine FLUDV but different from those described previously in experimental infections in ferrets and swine with a swine FLUDV, which supported virus replication only in the upper respiratory tract and not in the lower respiratory tract, including lung. Our study established that guinea pigs could be used as an animal model for studying this newly emerging influenza virus. Influenza D virus (FLUDV) is a novel emerging pathogen with bovine as its primary host. The epidemiology and pathogenicity of the virus are not yet known. FLUDV also spreads to swine, and the presence of FLUDV-specific antibodies in humans could indicate that there is a potential for zoonosis. Our results showed that bovine FLUDV replicated in the nasal turbinate and lungs of guinea pigs at high titers and was also able to transmit from an infected animal to sentinel animals by contact. The fact that bovine FLUDV replicated productively in both the upper and lower respiratory tracts of guinea pigs

  13. Replication and Transmission of the Novel Bovine Influenza D Virus in a Guinea Pig Model

    PubMed Central

    Sreenivasan, Chithra; Thomas, Milton; Sheng, Zizhang; Hause, Ben M.; Collin, Emily A.; Knudsen, David E. B.; Pillatzki, Angela; Nelson, Eric; Wang, Dan; Kaushik, Radhey S.

    2015-01-01

    ABSTRACT Influenza D virus (FLUDV) is a novel influenza virus that infects cattle and swine. The goal of this study was to investigate the replication and transmission of bovine FLUDV in guinea pigs. Following direct intranasal inoculation of animals, the virus was detected in nasal washes of infected animals during the first 7 days postinfection. High viral titers were obtained from nasal turbinates and lung tissues of directly inoculated animals. Further, bovine FLUDV was able to transmit from the infected guinea pigs to sentinel animals by means of contact and not by aerosol dissemination under the experimental conditions tested in this study. Despite exhibiting no clinical signs, infected guinea pigs developed seroconversion and the viral antigen was detected in lungs of animals by immunohistochemistry. The observation that bovine FLUDV replicated in the respiratory tract of guinea pigs was similar to observations described previously in studies of gnotobiotic calves and pigs experimentally infected with bovine FLUDV but different from those described previously in experimental infections in ferrets and swine with a swine FLUDV, which supported virus replication only in the upper respiratory tract and not in the lower respiratory tract, including lung. Our study established that guinea pigs could be used as an animal model for studying this newly emerging influenza virus. IMPORTANCE Influenza D virus (FLUDV) is a novel emerging pathogen with bovine as its primary host. The epidemiology and pathogenicity of the virus are not yet known. FLUDV also spreads to swine, and the presence of FLUDV-specific antibodies in humans could indicate that there is a potential for zoonosis. Our results showed that bovine FLUDV replicated in the nasal turbinate and lungs of guinea pigs at high titers and was also able to transmit from an infected animal to sentinel animals by contact. The fact that bovine FLUDV replicated productively in both the upper and lower respiratory tracts

  14. Worm recovery and precipitin antibody response in guinea pigs and rats infected with Clonorchis sinensis.

    PubMed

    Su, K E; Wang, F Y; Chi, P Y

    1998-12-01

    Guinea pigs (Hartley strain) and rats (Wistar strain) were each fed 200 and 100 Clonorchis sinensis metacercariae, respectively. Five animals from each species were sacrificed weekly between 1-8 weeks postinfection (WPI) and then at 12, 16, 20 and 30 WPI for collection of worms, bile and sera. The overall worm recovery rates for guinea pigs and rats were 18.7% and 12.4%, respectively. Only one of the five rats examined at 20 WPI still harbored one worm, while all were worm-free at 30 WPI. By a double diffusion test, no antibodies were detected against C. sinensis adult antigens in the bile juice. Serum antibodies were detected in at least 95% of the infected guinea pigs between 4-30 WPI and rats between 3-16 WPI. Precipitin antibodies seemed to be correlated with the presence of live worms in rats that had been infected for more than 12 weeks.

  15. Automaintenance in guinea pigs: effects of feeding regimen and omission training1

    PubMed Central

    Poling, Alan; Poling, Teresa

    1978-01-01

    Behavior maintained by stimulus-reinforcer pairings was examined. Guinea pigs maintained at 85 per cent of free-feeding weights reliably contacted a retractable lever presented before delivery of a single piece of guinea-pig chow or a 45-milligram guinea-pig pellet. When animals were given free access to one food and received the second food preceded by the lever, contact responses persisted. Such responses seldom occurred when a single food was freely available and was also delivered after lever presentation. Introduction of an omission training (negative automaintenance) procedure, in which lever contacts resulted in lever retraction and prevented food delivery, strongly reduced lever contacts. Observation indicated that mouthing the food cup, instead of the lever, became the prominent behavior during the prefood stimulus under the omission training procedure. PMID:16812086

  16. Effect of experimental zinc deficiency and repletion on some immunological variables in guinea-pigs.

    PubMed

    Verma, P C; Gupta, R P; Sadana, J R; Gupta, R K

    1988-01-01

    1. Cellular and humoral immune responses were studied in guinea-pigs fed on zinc-deficient (ZnD), Zn-adequate (control) and Zn-replete diets containing 1.25, 50 and 100 mg Zn/kg diet respectively. 2. It was found that the ZnD guinea-pigs had significantly decreased ability to elicit delayed-type hypersensitivity (DTH) response against sheep erythrocytes as compared with controls on the 9th day of immunization. This was further substantiated by histological examination of DTH-positive skin sections. 3. A significant reduction in direct splenic plaque-forming-cell response and haemagglutinating-antibody titre was also observed in ZnD guinea-pigs. 4. Serum electrophoretic studies revealed a highly disordered protein profile with a significantly depressed value for gamma-globulin. 5. Zn repletion of the previously ZnD group resulted in marked, though incomplete, restoration of immunological responses.

  17. Spasmolytic activity of a herbal drug isolated from Tephrosia purpurea in guinea pigs.

    PubMed

    Soni, Kapil K; Khare, M L; Saxena, R C

    2004-04-01

    We investigated the spasmolytic activity of herbal drugs isolated from Tephrosia purpurea on guinea pigs for the treatment of asthma in India. For this investigation, the herbal drug was extracted with 70% ethanol in soxhlet apparatus. After purification and isolution, the drug was used in experimental animals to observe prophylactic activity. For anaphylactic activity, horse serum 0.5 ml along with triple antigen (0.5 ml) was induced in guinea pigs. To observe prophylactic activity, male guinea pigs weighing about 250-450 gms were killed by cervical dislocation and the trachea was isolated. Each trachea was cut in to six segments. Each segment consists of three cartilage rings. Each end of tracheal muscles was attached to the bronchospasm transducers for isometric recording of the tension charges on a polygraph. The results of experiments clearly showed the spasmolytic activity of the drug. The preliminary phytochemical investigation, however shows the presence of glycoside saponins.

  18. Inhibition of gastric secretion in guinea pig by relatively low dose ionizing radiation

    SciTech Connect

    Batzri, S.; Catravas, G.

    1988-11-01

    We evaluated the effect of a single dose of ionizing radiation on gastric secretion in awake guinea pigs equipped with a permanent gastric cannula. Changes in gastric secretion were measured using a dye dilution technique. Infusion of histamine increased acid and fluid output and there was a positive correlation (r = 0.93) between the two. Total body irradiation with 400 cGy, like cimetidine, suppressed acid and fluid secretion under basal conditions and during histamine stimulation by 50-90%. Recovery from the radiation damage was only partial after one week. Irradiation inhibited the rise in gastric juice volume during histamine stimulation and also reduced the normal gain in body weight of the guinea pig. These results demonstrate that ionizing radiations have an immediate and long lasting effects on the gastric mucosal function of the guinea pig.

  19. Pathological and virological features of arenavirus disease in guinea pigs. Comparison of two Pichinde virus strains.

    PubMed

    Aronson, J F; Herzog, N K; Jerrells, T R

    1994-07-01

    A guinea pig passage-adapted strain of the arena-virus Pichinde (adPIC) is highly virulent in inbred guinea pigs, whereas the related strain PIC3739 is attenuated. Both viruses were macrophage tropic and infected peritoneal, splenic, liver, and alveolar macrophages during experimental Pichinde virus infection. Infection with the virulent strain was associated with unlimited viral replication in the face of exaggerated delayed-type hypersensitivity response, manifested by the macrophage disappearance reaction. Histopathological lesions unique to adPIC-infected guinea pigs included intestinal villus blunting with mucosal infiltration by pyknotic debris-laden macrophages and apoptosis of crypt epithelial cells. Splenic red pulp necrosis was also significantly associated with adPIC infection but not PIC3739 infection. These findings may provide clues to the pathogenesis of a group of poorly understood human viral hemorrhagic fevers.

  20. Pathological and virological features of arenavirus disease in guinea pigs. Comparison of two Pichinde virus strains.

    PubMed Central

    Aronson, J. F.; Herzog, N. K.; Jerrells, T. R.

    1994-01-01

    A guinea pig passage-adapted strain of the arena-virus Pichinde (adPIC) is highly virulent in inbred guinea pigs, whereas the related strain PIC3739 is attenuated. Both viruses were macrophage tropic and infected peritoneal, splenic, liver, and alveolar macrophages during experimental Pichinde virus infection. Infection with the virulent strain was associated with unlimited viral replication in the face of exaggerated delayed-type hypersensitivity response, manifested by the macrophage disappearance reaction. Histopathological lesions unique to adPIC-infected guinea pigs included intestinal villus blunting with mucosal infiltration by pyknotic debris-laden macrophages and apoptosis of crypt epithelial cells. Splenic red pulp necrosis was also significantly associated with adPIC infection but not PIC3739 infection. These findings may provide clues to the pathogenesis of a group of poorly understood human viral hemorrhagic fevers. Images Figure 6 Figure 7 PMID:8030751

  1. [In vitro inhibition of celastrol on spermatozoa fertilization ability of guinea pig].

    PubMed

    Yuan, Y Y; Gu, Z P; Shi, Q X; Qin, G W; Xu, R S; Cao, L

    1995-01-01

    The effects of celastrol (Cel), isolated from Tripterygium wilfordii, on guinea pig sperm forward motility (FM), capacitation (Cap), the acrosome reaction (AR) and sperm penetration assay (SPA) were assessed in vitro. Cel (5 micrograms.ml-1) was found to inhibit these spermatozoal functions, and the inhibitions were proportional to the concentrations of Cel used. The potency of inhibition of Cel on the fertilizing ability in guinea pig spermatozoa in vitro seems to follow the order: Cap > FM > SPA > AR. The inhibitory effect appeared to be reversible after washing away Cel if the duration of exposure of spermatozoa to Cel was shorter than 3 h. In a comparative study, the inhibitory effects of Cel on guinea pig sperm FM and AR were significantly stronger than those of gossypol acetic acid.

  2. Effects of oral administration of trimethoprim-sulfamethoxazole on tear production in clinically normal guinea pigs.

    PubMed

    Asadi, Faezeh; Rajaei, Seyed Mehdi; Golabdar, Salar

    2016-09-01

    To determine the effects of short-term oral administration of trimethoprim-sulfamethoxazole on tear production in clinically normal guinea pigs. Thirty-two healthy adult Abyssinian guinea pigs were used in this study. One day before the start of the trial, the pretreatment baseline phenol red thread test (PRTT) values were recorded. Sixteen guinea pigs in the treated group received 25 mg/kg trimethoprim-sulfamethoxazole orally twice a day for 14 days. The other sixteen guinea pigs were used as untreated controls and received a placebo during the study. All the ophthalmic tests were performed without chemical restraint. PRTT values were evaluated in both eyes of all the guinea pigs using a commercial PRTT strip of a single lot number on days 0 (baseline), 15, and 21 after starting the trial. The pretreatment baseline mean ± SD PRTT values for the treatment and control groups were 11.12 ± 3.82 mm/15 s and 11.93 ± 2.73 mm/15 s, respectively. After 14 days of drug administration, the mean ± SD PRTT values for the treatment and control groups were 10.87 ± 3.11 mm/15 s and 13.00 ± 2.47 mm/15 s, respectively. On Day 21, the mean ± SD PRTT values for the treatment and control groups were 12.62 ± 4.05 mm/15 s and 12.87 ± 2.99 mm/15 s, respectively. Significant decreases in the PRTT values, compared with the pretreatment baseline values, were not observed in the treatment group on Day 15 (P = 0.14) and Day 21 (P = 0.31). Trimethoprim-sulfamethoxazole did not decrease tear production in the guinea pigs in this study. © 2015 American College of Veterinary Ophthalmologists.

  3. Conjugated linoleic acid mitigates testosterone-related changes in body composition in male guinea pigs.

    PubMed

    Yang, Susan Q; DeGuire, Jason R; Lavery, Paula; Mak, Ivy L; Weiler, Hope A; Santosa, Sylvia

    2016-05-01

    We hypothesize that conjugated linoleic acid (CLA) may be effective in preventing the changes in total and regional body composition and increases in interleukin (IL) 6 that occur as a result of hypogonadism. Male guinea pigs (n = 40, 70- to 72-week retired breeders) were block randomized by weight into 4 groups: (1) sham surgery (SHAM)/control (CTRL) diet, (2) SHAM/conjugated linoleic acid (CLA) diet (1%), (3) orchidectomy (ORX)/CTRL diet, and (4) ORX/CLA diet. Dual-energy x-ray absorptiometry scans were performed at baseline and week 16 to assess body composition. Serum IL-6 was analyzed using an enzyme-linked immune sorbent assay. Fatty acids (FAs) from visceral and subcutaneous adipose tissue were analyzed using gas chromatography. In ORX/CTRL guinea pigs, percent total body fat increased by 6.1%, and percent lean mass decreased by 6.7% over the 16-week treatment period, whereas no changes were observed for either parameter in ORX/CLA guinea pigs. Guinea pigs fed the CLA diet gained less percent total, upper, and lower body fat than those fed the CTRL diet regardless of surgical treatment. Regional adipose tissue FA composition was reflective of dietary FAs. Serum IL-6 concentrations were not different among groups. In this study, we observed that, in male guinea pigs, hypogonadism resulted in increased fat mass and decreased lean mass. In addition, CLA was effective in reducing gains in body fat and maintaining lean mass in both hypogonadal and intact guinea pigs. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Adenosine transport systems on dissociated brain cells from mouse, guinea-pig, and rat

    SciTech Connect

    Johnston, M.E.; Geiger, J.D. )

    1990-09-01

    The kinetics and sodium dependence of adenosine transport were determined using an inhibitor-stop method on dissociated cell body preparations obtained from mouse, guinea-pig and rat brain. Transport affinity (KT) values for the high affinity adenosine transport systems KT(H) were significantly different between these three species; mean +/- SEM values were 0.34 +/- 0.1 in mouse, 0.9 +/- 0.2 in rat, and 1.5 +/- 0.5 microM in guinea-pig. The KT values for the low affinity transport system KT(L) were not different between the three species. Brain cells from rat displayed a significantly greater maximal capacity to accumulate (3H)adenosine (Vmax) than did mouse or guinea-pig for the high affinity system, or than did mouse for the low affinity system. When sodium chloride was replaced in the transport medium with choline chloride, the KT(H) values for guinea-pig and rat were both increased by approximately 100%; only in rat did the change reach statistical significance. The sodium-dependence of adenosine transport in mouse brain was clearly absent. The differences between KT(H) values in mouse and those in guinea-pig or rat were accentuated in the absence of sodium. The differences in kinetic values, ionic requirements, and pharmacological characteristics between adenosine transporters in CNS tissues of mouse, guinea-pig and rat may help account for some of the variability noted among species in terms of their physiological responses to adenosine.

  5. Species differences in the localization and number of CNS beta adrenergic receptors: Rat versus guinea pig

    SciTech Connect

    Booze, R.M.; Crisostomo, E.A.; Davis, J.N.

    1989-06-01

    The localization and number of beta adrenergic receptors were directly compared in the brains of rats and guinea pigs. The time course of association and saturability of (125I)cyanopindolol (CYP) binding to slide-mounted tissue sections was similar in rats (Kd = 17 pM) and guinea pigs (Kd = 20 pM). The beta-1 and beta-2 receptor subtypes were examined through the use of highly selective unlabeled receptor antagonists, ICI 118,551 (50 nM) and ICI 89,406 (70 nM). Dramatic species differences between rats and guinea pigs were observed in the neuroanatomical regional localization of the beta adrenergic receptor subtypes. For example, in the thalamus prominent beta-1 and beta-2 receptor populations were identified in the rat; however, the entire thalamus of the guinea pig had few, if any, beta adrenergic receptors of either subtype. Hippocampal area CA1 had high levels of beta-2 adrenergic receptors in both rats and guinea pigs but was accompanied by a widespread distribution of beta-2 adrenergic receptors only in rats. Quantitative autoradiographic analyses of 25 selected neuroanatomical regions (1) confirmed the qualitative differences in CNS beta adrenergic receptor localization, (2) determined that guinea pigs had significantly lower levels of beta adrenergic receptors than rats and (3) indicated a differential pattern of receptor subtypes between the two species. Knowledge of species differences in receptor patterns may be useful in designing effective experiments as well as in exploring the relationships between receptor and innervation patterns. Collectively, these data suggest caution be used in extrapolation of the relationships of neurotransmitters and receptors from studies of a single species.

  6. Rifapentine is not more active than rifampin against chronic tuberculosis in guinea pigs.

    PubMed

    Dutta, Noton K; Illei, Peter B; Peloquin, Charles A; Pinn, Michael L; Mdluli, Khisimuzi E; Nuermberger, Eric L; Grosset, Jacques H; Karakousis, Petros C

    2012-07-01

    Rifamycins are key sterilizing drugs in the current treatment of active tuberculosis (TB). Daily dosing of rifapentine (P), a potent rifamycin with high intracellular accumulation, in place of rifampin (R) in the standard antitubercular regimen significantly shortens the duration of treatment needed to prevent relapse in a murine model of active TB. We undertook the current study to compare directly the activities of human-equivalent doses of P and R in a guinea pig model of chronic TB, in which bacilli are predominantly extracellular within human-like necrotic granulomas. Hartley strain guinea pigs were aerosol infected with ~200 bacilli of Mycobacterium tuberculosis H37Rv, and treatment given 5 days/week was initiated 6 weeks later. R at 100 mg/kg of body weight and P at 100 mg/kg were given orally alone or in combination with isoniazid (H) at 60 mg/kg and pyrazinamide (Z) at 300 mg/kg. Culture-positive relapse was assessed in subgroups of guinea pigs after completion of 1 and 2 months of treatment. Human-equivalent doses of R and P showed equivalent bactericidal activity when used alone and in combination therapy. In guinea pigs treated with rifampin, isoniazid, and pyrazinamide (RHZ) or PHZ, microbiological relapse occurred in the lungs of 8/10 animals treated for 1 month and in 0/10 animals treated for 2 months. Substitution of P for R in the standard antitubercular regimen did not shorten the time to cure in this guinea pig model of chronic TB. Data from ongoing clinical trials comparing the activity of these two drugs are awaited to determine the relevance of the guinea pig TB model in preclinical drug screening.

  7. Rifapentine Is Not More Active than Rifampin against Chronic Tuberculosis in Guinea Pigs

    PubMed Central

    Dutta, Noton K.; Illei, Peter B.; Peloquin, Charles A.; Pinn, Michael L.; Mdluli, Khisimuzi E.; Nuermberger, Eric L.; Grosset, Jacques H.

    2012-01-01

    Rifamycins are key sterilizing drugs in the current treatment of active tuberculosis (TB). Daily dosing of rifapentine (P), a potent rifamycin with high intracellular accumulation, in place of rifampin (R) in the standard antitubercular regimen significantly shortens the duration of treatment needed to prevent relapse in a murine model of active TB. We undertook the current study to compare directly the activities of human-equivalent doses of P and R in a guinea pig model of chronic TB, in which bacilli are predominantly extracellular within human-like necrotic granulomas. Hartley strain guinea pigs were aerosol infected with ∼200 bacilli of Mycobacterium tuberculosis H37Rv, and treatment given 5 days/week was initiated 6 weeks later. R at 100 mg/kg of body weight and P at 100 mg/kg were given orally alone or in combination with isoniazid (H) at 60 mg/kg and pyrazinamide (Z) at 300 mg/kg. Culture-positive relapse was assessed in subgroups of guinea pigs after completion of 1 and 2 months of treatment. Human-equivalent doses of R and P showed equivalent bactericidal activity when used alone and in combination therapy. In guinea pigs treated with rifampin, isoniazid, and pyrazinamide (RHZ) or PHZ, microbiological relapse occurred in the lungs of 8/10 animals treated for 1 month and in 0/10 animals treated for 2 months. Substitution of P for R in the standard antitubercular regimen did not shorten the time to cure in this guinea pig model of chronic TB. Data from ongoing clinical trials comparing the activity of these two drugs are awaited to determine the relevance of the guinea pig TB model in preclinical drug screening. PMID:22547623

  8. The protective effect of Nigella sativa on lung injury of sulfur mustard-exposed Guinea pigs.

    PubMed

    Hossein, Boskabady Mohammad; Nasim, Vahedi; Sediqa, Amery

    2008-05-01

    The lung is one of the most exposable organs to chemical warfare agents such as sulfur mustard (SM) gas. Airway hyperresponsiveness and lung inflammation are reported in chemical warfare victims. There is no definite treatment for respiratory disorders induced by SM exposure. However, the protective effect of Nigella sativa on inflammatory process was shown. In the present study, the protective effect of Nigella sativa on tracheal responsiveness and lung inflammation of SM exposed guinea pigs was examined. Guinea pigs were exposed to diluent's solution (ethanol, control group), 100 mg/m(3) inhaled sulfur mustard (SME group), and SME treated with Nigella sativa, 0.08 g daily (SME+N), n = 6 for each group. Tracheal responsiveness (TR) to methacholine, total white blood cell (WBC) count of lung lavage, and differential WBC were done 14 days post exposure. The weigh of animal were measured at the beginning, middle (day 7), and the end (day 14) of the study. The TR of SM-exposed guinea pigs was significantly (P < .001) and WBC nonsignificantly higher than those of controls. In SME guinea pigs, there was a weight loss but in the case of SME+N guinea pigs, no obvious weight change thought the study was seen. The eosinophl, monocyte, and lympocytes in SME animals were significantly changed compared to control group (P < .001 for all cases). Monocyte, lymphocyte, and neutrophil number were decreased in SME+N group compared to SME animals, which was significant only for neutrophil (P < .05). These results showed a preventive effect of Nigella sativa on TR of SM-exposed guinea pigs.

  9. Role of interleukin-5 in enhanced migration of eosinophils from airways of immunized guinea-pigs.

    PubMed Central

    Coëffier, E; Joseph, D; Vargaftig, B B

    1994-01-01

    1. Platelet activating factor (PAF), leukotriene B4 (LTB4) and interleukin-5 (IL-5) are potent chemoattractants for guinea-pig eosinophils, which may be involved in eosinophil recruitment and up-regulation in allergic diseases. Eosinophils from the bronchoalveolar lavage fluid (BALF) of ovalbumin-sensitized guinea-pigs were collected 24 h after antigen provocation and migration induced by PAF, LTB4 and rhIL-5 was studied. 2. Total BALF content and distribution of eosinophils were greater in immunized, ovalbumin-challenged guinea-pigs (5.0 +/- 0.8 x 10(6)/guinea-pig; 12 +/- 1%) than in immunized, saline-challenged animals (3.0 +/- 0.7 x 10(6)/guinea-pig; 7 +/- 1%). 3. The chemoattraction of eosinophils isolated on a metrizamide gradient was studied in micro-Boyden chambers, results being expressed as the number of migrating cells (mean +/- s.e. mean). PAF and LTB4-induced migration of eosinophils from immunized and OA-challenged guinea-pigs were significantly enhanced, as compared to immunized and saline-challenged animals (170 +/- 36 vs 35 +/- 9 migrating eosinophils for 10 nM PAF; 271 +/- 60 vs 110 +/- 19 for 1 nM LTB4). 4. The IL-5 antibody TRFK-5, in vivo, reduced eosinophil recruitment in BALF of antigen-challenged immunized animals as well as the enhanced responsiveness of eosinophils from the challenged animals, suggesting a role for IL-5 in the priming of eosinophils in vivo. 5. In contrast to TRFK-5, nedocromil sodium reduced to a similar extent eosinophil, macrophage and lymphocyte recruitment into the BALF of antigen-challenged, but failed to down-regulate the enhanced responsiveness of eosinophils from the challenged animals.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7858864

  10. Onset and duration of immunity in guinea pigs and mice induced with different Q fever vaccines.

    PubMed

    Kazár, J; Votruba, D; Propper, P; Schramek, S

    1986-11-01

    Protective effects of different types of Q fever vaccines, namely untreated Coxiella burnetii phase I cells (Cb I) or Cb I cells treated with chloroform-methanol (CM) mixture (Cb I-CM) and of a Q fever chemovaccine obtained by trichloroacetic acid extraction (TCAE) from intact Cb I cells, were compared in mice and guinea pigs at different intervals after intraperitoneal (i.p.) or subcutaneous (s.c.) immunizations. The highest degree of protection at all intervals studied was achieved with Cb I cells, irrespective of the route of immunization and i.p. or aerosol challenge. This vaccine exerted a protective effect in guinea pigs and mice as early as after one or two weeks post-immunization, the effect lasting for at least 40 weeks in mice (i.p. challenge) and 12 months in guinea pigs (aerosol challenge). Addition of small amount of Cb I cells to TCAE increased resistance of guinea pigs to aerosol challenge. Degree, onset and duration of protection to either type of virulent challenge afforded by Cb I-CM cells and TCAE was similar, but when compared with that of Cb I cells it was lower, started later (from the 2nd week in guinea pigs and the 3rd week in mice), and in mice it lasted for a shorter period (20 weeks only). The resistance to virulent challenge in guinea pigs did not depend on the levels of microagglutination (MA) antibodies and in mice it was reflected by delayed type hypersensitivity (DTH) reaction and adoptively transferred splenocytes, rather than by MA antibody titres and passive transfer of immune sera to recipient mice.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Excitatory motor and electrical effects produced by tachykinins in the human and guinea-pig isolated ureter and guinea-pig renal pelvis

    PubMed Central

    Patacchini, Riccardo; Santicioli, Paolo; Zagorodnyuk, Vladimir; Lazzeri, Massimo; Turini, Damiano; Alberto Maggi, Carlo

    1998-01-01

    In isolated tissue experiments, neurokinin A (NKA) produced concentration-dependent contraction of human and guinea-pig ureter (pD2=6.7 and 7.2, respectively); an effect greatly reduced (>80% inhibition) by the tachykinin NK2 receptor-selective antagonist MEN 11420 (0.1 μM). The tachykinin NK1 and NK3 receptor agonists septide and senktide, respectively, were ineffective.Electrical field stimulation (EFS) of the guinea-pig isolated renal pelvis produced an inotropic response blocked by MEN 11420 (0.01–1 μM). In the same preparation MEN 11420 (0.1 μM) blocked (apparent pKB=8.2) the potentiation of spontaneous motor activity produced by the NK2 receptor-selective agonist [βAla8]NKA(4–10).In sucrose-gap experiments, EFS evoked action potentials (APs) accompanied by phasic contractions of human and guinea-pig ureter, which were unaffected by tetrodotoxin or MEN 11420 (3 μM), but were blocked by nifedipine (1–10 μM). NKA (1–3 μM) produced a slow membrane depolarization with superimposed APs and a tonic contraction with superimposed phasic contractions. NKA prolonged the duration of EFS-evoked APs and potentiated the accompanying contractions. MEN 11420 completely prevented the responses to NKA in both the human and guinea-pig ureter.Nifedipine (1–10 μM) suppressed the NKA-evoked APs and phasic contractions in both human and guinea-pig ureter, and slightly reduced the membrane depolarization induced by NKA. A tonic-type contraction of the human ureter in response to NKA persisted in the presence of nifedipine.In conclusion, tachykinins produce smooth muscle excitation in both human and guinea-pig ureter by stimulating receptors of the NK2 type only. NK2 receptor activation depolarizes the membrane to trigger the firing of APs from latent pacemakers. PMID:9846636

  12. Evidence for a non-opioid sigma binding site din the guinea-pig myenteric plexus

    SciTech Connect

    Roman, F.; Pascaud, X.; Vauche, D.; Junien, J.

    1988-01-01

    The presence of a binding site to (+)-(/sup 3/H)SKF 10,047 was demonstrated in a guinea-pig myenteric plexus (MYP) membrane preparation. Specific binding to this receptor was saturable, reversible, linear with protein concentration and consisted of two components, a high affinity site and a low affinity site. Morphine and naloxone 10/sup -4/M were unable to displace (+)-(/sup 3/H)SKF 10,047 binding. Haloperidol, imipramine, ethylketocyclazocine and propranolol were among the most potent compounds to inhibit this specific binding. These results suggest the presence of a non-opioid haloperidol sensitive sigma receptor in the MYP of the guinea-pig.

  13. The role of pheromones in the regulation of estrous cycle duration in the guinea pig.

    PubMed

    Jesel, L; Aron, C L

    1976-01-01

    A decrease in estrous cycle duration, due to shortening of the period of vaginal closure (VC), has been observed in female guinea pigs exposed to the odor of urine from males of the same species. VC shortening was also observed in females exposed to the odor of female urine collected during the period of vaginal opening (VO). No alteration in VC duration occurred, however, in females exposed to urine collected in the 1st 7 days of VC. Also VC shortening did not occur in bulbectomized females exposed to the odor of male urine. Therefore, it was concluded that guinea pig urine, when highly concentrated, contains pheromones capable of shortening estrous cycle VC.

  14. Vesicular Lesions Produced in Guinea Pigs by a Staphylococcus aureus Strain

    PubMed Central

    Tessler, J.

    1973-01-01

    A bacterium isolated from vesicular lesions on foot pads of guinea pigs reproduced lesions similar to those seen in experimental infections of guinea pigs with foot-and-mouth disease virus. (FMDV). These bacterial lesions were produced with an inactivated FMDV suspension. Identification as Staphylococcus aureus was determined by growth characteristics on nutrient and blood agar, Gram staining, fermentation of mannitol and coagulase positive reactions. In addition, the organism was sensitive to concentrations of penicillin and streptomycin commonly used in laboratory diluents. PMID:4355472

  15. Optic nerve head and intraocular pressure in the guinea pig eye.

    PubMed

    Ostrin, Lisa A; Wildsoet, Christine F

    2016-05-01

    The guinea pig is becoming an increasingly popular model for studying human myopia, which carries an increased risk of glaucoma. As a step towards understanding this association, this study sought to characterize the normal, developmental intraocular pressure (IOP) profiles, as well as the anatomy of the optic nerve head (ONH) and adjacent sclera of young guinea pigs. IOP was tracked in pigmented guinea pigs up to 3 months of age. One guinea pig was imaged in vivo with OCT and one with a fundus camera. The eyes of pigmented and albino guinea pigs (ages 2 months) were enucleated and sections from the posterior segment, including the ONH and surrounding sclera, processed for histological analyses - either hematoxylin and eosin (H&E) staining of paraffin embedded, sectioned tissue (n = 1), or cryostat sectioned tissue, processed for immunohistochemistry (n = 3), using primary antibodies against collagen types I-V, elastin, fibronectin and glial fibrillary acidic protein (GFAP). Transmission and scanning electron microscopy (TEM, SEM) studies of ONHs were also undertaken (n = 2 & 5 respectively). Mean IOPs ranged from 17.33 to 22.7 mmHg, increasing slightly across the age range studied, and the IOPs of individual animals also exhibited diurnal variations, peaking in the early morning (mean of 25.8, mmHg, ∼9 am), and decreasing across the day. H&E-stained sections showed retinal ganglion cell axons organized into fascicles in the prelaminar and laminar region of the ONHs, with immunostained sections revealing collagen types I, III, IV and V, as well as elastin, GFAP and fibronectin in the ONHs. SEM revealed a well-defined lamina cribrosa (LC), with radially-oriented collagen beams. TEM revealed collagen fibrils surrounding non-myelinated nerve fiber bundles in the LC region, with myelination and decreased collagen posterior to the LC. The adjacent sclera comprised mainly crimped collagen fibers in a crisscross arrangement. Both the sclera and LC were

  16. BCG vaccination enhances resistance to M. tuberculosis infection in guinea pigs fed a low casein diet.

    PubMed

    Sugawara, Isamu; Yamada, Hiroyuki; Mizuno, Satoru

    2007-03-01

    In order to examine the relationship between malnutrition and tuberculosis development in vivo, a malnourished guinea pig model fed with a low casein (5%) diet was developed. After being fed with the low casein diet, the guinea pigs were infected with Mycobacterium (M.) tuberculosis Kurono strain by aerosol infection, and seven weeks later were subjected to histopathologic examination, colony-forming unit (CFU) assay, fluorescence-activated cell sorter (FACS) analysis and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-12 and inducible nitric oxide synthase (iNOS) mRNA. Another group of guinea pigs were vaccinated subcutaneously with 10(6) CFU BCG Tokyo for three weeks and then similarly infected by aerosol. Eighty-eight% (7/8) of the malnourished guinea pigs succumbed to mycobacterial infection within 85 days after infection, while the malnourished guinea pigs vaccinated with BCG Tokyo survived. CFU assay showed that lung and splenic CFUs were higher in the low casein diet-fed groups than in the control diet (20% casein)-fed groups, although both groups had significantly lower CFUs after vaccination with BCG Tokyo (p<0.01). Examination of lung histopathology revealed that pulmonary granulomas were large and disorganized in the groups fed the low casein diet. The number of visible lesions on the surfaces of the fixed lungs in guinea pigs fed control diet+BCG and low casein diet+BCG was low significantly. Pan T-, CD4-, CD8- and Mac antigen-positive cells were also recognized in the infected lung tissues of low casein-fed guinea pigs and Pan T-, CD4- and Mac antigen-positive cells increased after vaccination with BCG Tokyo. Expression of IFN-gamma, TNF-alpha, IL-12 and iNOS mRNA was also recognized in the infected lung tissues of low casein-fed guinea pigs and IFN-gamma and TNF-alpha mRNA expression was enhanced with BCG vaccination. These results indicate that

  17. Serological response of guinea pigs to oily and aqueous inactivated vaccines containing a Brazilian isolate of the Bovine Viral Diarrhea Virus (BVDV).

    PubMed

    Jordão, Ricardo Spacagna; Ribeiro, Cláudia Pestana; Pituco, Edviges Maristela; Okuda, Líria Hiromi; Del Fava, Cláudia; Stefano, Eliana de; Filho, Moacir Marchiori; Mehnert, Dolores Ursula

    2011-10-01

    Bovine Viral Diarrhea Virus (BVDV) is widespread in cattle in Brazil and research shows its large antigenic variability. Available vaccines are produced with virus strains isolated in other countries and may not be effective. In this study, inactivated vaccines containing the Brazilian BVDV-Ib IBSP11 isolate were developed and tested on 6 groups of 10 guinea pigs (Cavia porcellus). Animals in groups A and C received an aqueous vaccine (aluminum hydroxide); B and D groups received an oily vaccine (Montanide ISA50); Group E positive-control animals were given an imported commercial vaccine with BVDV-Ia Singer; Group F animals were sham vaccinated (negative control). Groups A, B and E received two doses, and Groups C and D, three, every 21 days. Twelve blood samples were taken, at 21-day intervals over 231 days, and evaluated for antibody titer through virus-neutralization (VN), using a homologous strain (IBSP11), and a heterologous strain (BVDV-Ia NADL). Most animals, 42 days following the first dose, seroconverted to both strains and, after the second dose, there was a significant increase of titers in all groups. The oily formulation induced greater response after the third administration. This increase was not observed with the aqueous vaccines, regardless of the virus used in the VN. Antibody decline was more rapid in animals that received aqueous vaccines. The results showed the importance of studying the influence of endemic strains of commercial vaccines, to improve the efficacy of BVD vaccination. Use of the endemic strain in vaccine formulation presented promising results, as well as the use of guinea pigs as a laboratory model.

  18. Beam-Beam Interaction Simulations with Guinea Pig (LCC-0125)

    SciTech Connect

    Sramek, C

    2003-11-20

    At the interaction point of a particle accelerator, various phenomena occur which are known as beam-beam effects. Incident bunches of electrons (or positrons) experience strong electromagnetic fields from the opposing bunches, which leads to electron deflection, beamstrahlung and the creation of electron/positron pairs and hadrons due to two-photon exchange. In addition, the beams experience a ''pinch effect'' which focuses each beam and results in either a reduction or expansion of their vertical size. Finally, if a beam's disruption parameter is too large, the beam can develop a sinusoidal distortion, or two-stream (kink) instability. This project simulated and studied these effects as they relate to luminosity, deflection angles and energy loss in order to optimize beam parameters for the Next Linear Collider (NLC). Using the simulation program Guinea Pig, luminosity, deflection angle and beam energy data was acquired for different levels of beam offset and distortion. Standard deflection curves and luminosity plots agreed with theoretical models but also made clear the difficulties of e-e- feedback. Simulations emphasizing kink instability in modulated and straight beam collisions followed qualitative behavioral predictions and roughly fit recent analytic calculations. A study of e-e- collisions under design constraints for the NLC provided new estimates of how luminosity, beamstrahlung energy loss, upsilon parameter and deflection curve width scale with beam cross-sections ({sigma}{sub x}, {sigma}{sub y}, {sigma}{sub z}) and number of particles per bunch (N). Finally, this same study revealed luminosity maxima at large N and small {sigma}{sub y} which may merit further investigation.

  19. Pharmacometabolomic approach to predict QT prolongation in guinea pigs.

    PubMed

    Park, Jeonghyeon; Noh, Keumhan; Lee, Hae Won; Lim, Mi-sun; Seong, Sook Jin; Seo, Jeong Ju; Kim, Eun-Jung; Kang, Wonku; Yoon, Young-Ran

    2013-01-01

    Drug-induced torsades de pointes (TdP), a life-threatening arrhythmia associated with prolongation of the QT interval, has been a significant reason for withdrawal of several medicines from the market. Prolongation of the QT interval is considered as the best biomarker for predicting the torsadogenic risk of a new chemical entity. Because of the difficulty assessing the risk for TdP during drug development, we evaluated the metabolic phenotype for predicting QT prolongation induced by sparfloxacin, and elucidated the metabolic pathway related to the QT prolongation. We performed electrocardiography analysis and liquid chromatography-mass spectroscopy-based metabolic profiling of plasma samples obtained from 15 guinea pigs after administration of sparfloxacin at doses of 33.3, 100, and 300 mg/kg. Principal component analysis and partial least squares modelling were conducted to select the metabolites that substantially contributed to the prediction of QT prolongation. QTc increased significantly with increasing dose (r = 0.93). From the PLS analysis, the key metabolites that showed the highest variable importance in the projection values (>1.5) were selected, identified, and used to determine the metabolic network. In particular, cytidine-5'-diphosphate (CDP), deoxycorticosterone, L-aspartic acid and stearic acid were found to be final metabolomic phenotypes for the prediction of QT prolongation. Metabolomic phenotypes for predicting drug-induced QT prolongation of sparfloxacin were developed and can be applied to cardiac toxicity screening of other drugs. In addition, this integrative pharmacometabolomic approach would serve as a good tool for predicting pharmacodynamic or toxicological effects caused by changes in dose.

  20. Pharmacometabolomic Approach to Predict QT Prolongation in Guinea Pigs

    PubMed Central

    Lee, Hae Won; Lim, Mi-sun; Seong, Sook Jin; Seo, Jeong Ju; Kim, Eun-Jung; Kang, Wonku; Yoon, Young-Ran

    2013-01-01

    Drug-induced torsades de pointes (TdP), a life-threatening arrhythmia associated with prolongation of the QT interval, has been a significant reason for withdrawal of several medicines from the market. Prolongation of the QT interval is considered as the best biomarker for predicting the torsadogenic risk of a new chemical entity. Because of the difficulty assessing the risk for TdP during drug development, we evaluated the metabolic phenotype for predicting QT prolongation induced by sparfloxacin, and elucidated the metabolic pathway related to the QT prolongation. We performed electrocardiography analysis and liquid chromatography–mass spectroscopy-based metabolic profiling of plasma samples obtained from 15 guinea pigs after administration of sparfloxacin at doses of 33.3, 100, and 300 mg/kg. Principal component analysis and partial least squares modelling were conducted to select the metabolites that substantially contributed to the prediction of QT prolongation. QTc increased significantly with increasing dose (r = 0.93). From the PLS analysis, the key metabolites that showed the highest variable importance in the projection values (>1.5) were selected, identified, and used to determine the metabolic network. In particular, cytidine-5′-diphosphate (CDP), deoxycorticosterone, L-aspartic acid and stearic acid were found to be final metabolomic phenotypes for the prediction of QT prolongation. Metabolomic phenotypes for predicting drug-induced QT prolongation of sparfloxacin were developed and can be applied to cardiac toxicity screening of other drugs. In addition, this integrative pharmacometabolomic approach would serve as a good tool for predicting pharmacodynamic or toxicological effects caused by changes in dose. PMID:23593245

  1. Opioid receptors on guinea-pig intestinal crypt epithelial cells.

    PubMed Central

    Lang, M E; Davison, J S; Bates, S L; Meddings, J B

    1996-01-01

    1. Opioid peptides promote net intestinal absorption via two mechanisms: stimulation of Na+ and Cl- absorption and inhibition of Cl- secretion. Although these transport changes are predominantly mediated by submucosal neurones, it is currently unclear whether opioid peptides can regulate enterocyte function directly. We therefore tested the hypothesis that enterocytes have specific opioid receptors. 2. Villus and crypt jejunal epithelial cells were isolated by the distended sac method from anaesthetized guinea-pigs. Flow cytometry was used to resolve enterocytes from other cell types and to determine whether binding of a fluorescently labelled opioid antagonist, naltrexone-FITC, could be prevented by unlabelled mu- and delta-opioid receptor agonists. A population of crypt enterocytes (approximately 21%) exhibited high-affinity naltrexone-FITC binding to both mu- and delta-type binding sites that was stereoselective and sodium dependent. Villus enterocytes did not exhibit any of these characteristics. 3. Basal cAMP production was elevated in both villus and crypt cells treated with IBMX (3-isobutyl-1-methylxanthine). Villus cells did not respond to 100 nM vasoactive intestinal peptide (VIP), nor were they affected by opioid peptides. In contrast, 100 nM VIP significantly increased cAMP production in crypt epithelial cells, which was significantly reduced by both morphiceptin and D-Ser2-Leu-Enk-Thr. This opioid-mediated effect was stereoselective and blocked by the opioid receptor antagonist naltrexone. 4. These experiments suggest that enterocytes isolated from the crypt epithelium of guineapigs have both mu- and delta-types of opioid receptors. It is possible that these cells participate in opioid-mediated regulation of intestinal secretion. Images Figure 12 PMID:8951719

  2. Angiotensin receptors and actions in guinea pig enteric nervous system.

    PubMed

    Wang, Guo-Du; Wang, Xi-Yu; Hu, Hong-Zhen; Fang, Xiu-Cai; Liu, Sumei; Gao, Na; Xia, Yun; Wood, Jackie D

    2005-09-01

    Actions of ANG II on electrical and synaptic behavior of enteric neurons in the guinea pig small intestine were studied. Exposure to ANG II depolarized the membrane potential and elevated neuronal excitability. The number of responding neurons was small, with responses to ANG II in 32% of submucosal neurons and 25% of myenteric neurons. Hyperpolarizing responses were evoked by ANG II in 45% of the neurons. The hyperpolarizing responses were suppressed by alpha2-noradrenergic receptor antagonists, which suggested that the hyperpolarizing responses reflected stimulation of norepinephrine release from sympathetic neurons. Exposure to ANG II enhanced the amplitude and prolonged the duration of noradrenergic inhibitory postsynaptic potentials and suppressed the amplitude of both fast and slow excitatory postsynaptic potentials. The selective ANG II(1) receptor (AT1R) antagonists, ZD-7115 and losartan, but not a selective AT2R antagonist (PD-123319), suppressed the actions of ANG II. Western blot analysis and RT-PCR confirmed expression of AT1R protein and the mRNA transcript for the AT1R in the enteric nervous system. No expression of AT2R protein or mRNA was found. Immunoreactivity for AT1R was expressed by the majority of neurons in the gastric antrum and small and large intestine. AT1R immunoreactivity was coexpressed with calbindin, choline acetyltransferase, calretinin, neuropeptide Y, and nitric oxide synthase in subpopulations of neurons. The results suggest that formation of ANG II might have paracrine-like actions in the enteric nervous system, which include alterations in neuronal excitability and facilitated release of norepinephrine from sympathetic postganglionic axons. The enhanced presence of norepinephrine is expected to suppress fast and slow excitatory neurotransmission in the enteric microcircuits and to suppress neurogenic mucosal secretion.

  3. [+]-Huperzine A protects against soman toxicity in guinea pigs.

    PubMed

    Wang, Ying; Wei, Yanling; Oguntayo, Samuel; Jensen, Neil; Doctor, Bhupendra P; Nambiar, Madhusoodana P

    2011-12-01

    The chemical warfare nerve agent (CWNA) soman irreversibly inhibits acetylcholinesterase (AChE) causing seizure, neuropathology and neurobehavioral deficits. Pyridostigmine bromide (PB), the currently approved pretreatment for soman, is a reversible AChE inhibitor that does not cross the blood-brain barrier (BBB) to protect against central nervous system damage. [-]-Huperzine A, a natural reversible AChE inhibitor, rapidly passes through the BBB and has numerous neuroprotective properties that are beneficial for protection against soman. However, [-]-Huperzine A is toxic at higher doses due to potent AChE inhibition which limits the utilization of its neuroprotective properties. [+]-Huperzine A, a synthetic stereoisomer of [-]-Huperzine A and a weak inhibitor of AChE, is non-toxic. In this study, we evaluated the efficacy of [+]-Huperzine A for protection against soman toxicity in guinea pigs. Pretreatments with [+]-Huperzine A, i.m., significantly increased the survival rate in a dose-dependent manner against 1.2× LD(50) soman exposures. Behavioral signs of soman toxicity were significantly reduced in 20 and 40 mg/kg [+]-Huperzine A treated animals at 4 and 24 h compared to vehicle and PB controls. Electroencephalogram (EEG) power spectral analysis showed that [+]-Huperzine A significantly reduces soman-induced seizure compared to PB. [+]-Huperzine A (40 mg/kg) preserved higher blood and brain AChE activity compared to PB in soman exposed animals. These data suggest that [+]-Huperzine A protects against soman toxicity stronger than PB and warrant further development as a potent medical countermeasure against CWNA poisoning.

  4. Neurogenic mucosal bicarbonate secretion in guinea pig duodenum

    PubMed Central

    Fei, G; Fang, X; Wang, GD; Liu, S; Wang, XY; Xia, Y; Wood, JD

    2013-01-01

    Background and Purpose To test a hypothesis that: (i) duodenal pH and osmolarity are individually controlled at constant set points by negative feedback control centred in the enteric nervous system (ENS); (ii) the purinergic P2Y1 receptor subtype is expressed by non-cholinergic secretomotor/vasodilator neurons, which represent the final common excitatory pathway from the ENS to the bicarbonate secretory glands. Experimental Approach Ussing chamber and pH-stat methods investigated involvement of the P2Y1 receptor in neurogenic stimulation of mucosal bicarbonate (HCO3−) secretion in guinea pig duodenum. Key Results ATP increased HCO3− secretion with an EC50 of 160 nM. MRS2179, a selective P2Y1 purinergic receptor antagonist, suppressed ATP-evoked HCO3− secretion by 47% and Cl− secretion by 63%. Enteric neuronal blockade by tetrodotoxin or exposure to a selective vasoactive intestinal peptide (VIP, VPAC1) receptor antagonist suppressed ATP-evoked HCO3− secretion by 61 and 41%, respectively, and Cl- by 97 and 70% respectively. Pretreatment with the muscarinic antagonist, scopolamine did not alter ATP-evoked HCO3− or Cl− secretion. Conclusion and Implications Whereas acid directly stimulates the mucosa to release ATP and stimulate HCO3− secretion in a cytoprotective manner, neurogenically evoked HCO3− secretion accounts for feedback control of optimal luminal pH for digestion. ATP stimulates duodenal HCO3− secretion through an excitatory action at purinergic P2Y1 receptors on neurons in the submucosal division of the ENS. Stimulation of the VIPergic non-cholinergic secretomotor/vasodilator neurons, which are one of three classes of secretomotor neurons, accounts for most, if not all, of the neurogenic secretory response evoked by ATP. PMID:22994306

  5. Stability of the guinea pigs personality - cognition - linkage over time.

    PubMed

    Brust, Vera; Guenther, Anja

    2017-01-01

    In human psychological research, personality traits as well as cognitive traits are usually validated for both, their stability over time and contexts. While stability over time gives an estimate on how genetically fixated a trait can be, correlations across traits have the power to reveal linkages or trade - offs. In animals, these validations have widely been done for personality but not for cognitive traits. We tested guinea pigs in four consecutive discrimination tasks using four unique pairs of objects with two objects of the same form but different size in each pair. The same animals were tested twice each for three personality traits, i.e. boldness, aggression and sociopositive behaviour. The animals did not learn to "always choose the larger item" in the cognitive task but learned to discriminate the two objects of each stimulus pair anew, so that we did test for learning speed in four slightly different task setups. Performance over the four tasks was significantly repeatable as well as all tested personality traits. A stable linkage over time was found between sociopositive behaviour and learning performance, probably indicating an ecological relevance for a correlation between these two traits. Still, not all traits seem to be connected amongst each other, as in our case boldness and aggression are both not linked to individual learning performance. Future studies will hopefully further investigate the repeatability of various cognitive traits in several species and thus lead to a better understanding of the interdependence of personality and cognition. This will help to unravel which suites of traits facilitate individual life histories and hence improve our understanding of the emergence and maintenance of individual differences. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Biomechanical analysis of fracture healing in guinea-pigs.

    PubMed

    Kdolsky, Richard; Reihsner, Roland; Beer, Rudolf

    2008-01-01

    To validate the hypothesis that healing of fractures can be accelerated by oral administered L-arginine a guinea-pig model was chosen. A diaphyseal defect fracture was established in the right femur of each of the 32 small animals and stabilized. According to randomization groups the oral administration was realized (2 or 4 weeks medication / solvent). The following biomechanical variables were measured after 4 weeeks in 32 right femora and the corresponding uninjured left femora. The measurement for the healed femur was individually compared with that of the uninjured femur in each animal; bending, force (necessary for refracture) and energy (necessary for refracture). To apply the bending moment in a measurable and reproducible way each end of the femur was secured using a special device. For each femur a strain/momentum graph of the measurements and the essential parameters were drawn (stiffness, end of the linear range, and failure-point). The bending moment was always applied with the same loading rate. The following three variables were used for the biomechanical evaluation; bending stiffness, force until failure and energy necessary for refracture. The bending stiffness reached 73% by the control group and 88% by the 4-week treatment group. The force necessary for refracture was 52% in the control compared with 65% in the 4-week treatment group. The energy necessary for refracture was 36% in the control compared with 73% in the group treated for 4 weeks. The 2 week treatment group showed no statistical significant differences to the control, but the femora from the 4 week treatment group required statistically significant higher energy for refracture than the femora from the control.

  7. Macroscopic electrical propagation in the guinea pig urinary bladder.

    PubMed

    Hammad, F T; Stephen, B; Lubbad, L; Morrison, J F B; Lammers, W J

    2014-07-15

    There is little knowledge about macroscopic electrical propagation in the wall of the urinary bladder. Recording simultaneously from a large number of extracellular electrodes is one technology that could be used to study the patterns of macroscopic electrical propagations. The urinary bladders from 14 guinea pigs were isolated and placed in an organ bath. A 16 × 4-electrode array was positioned at various sites on the serosal bladder surface, and recordings were performed at different intravesical volumes. In four experiments, carbachol (CCH; 10(-6) M), nifedipine (10 mM), or tetrodotoxin (TTX; 10(-6) M) was added to the superfusing fluid. After the experiments, the extracellular signals were analyzed and propagation maps were constructed. Electrical waves were detected at all sites on the bladder surface and propagated for a limited distance before terminating spontaneously. The majority of waves (>90%) propagated in the axial direction (i.e., from dome to base or vice versa). An increase in vesicle volume significantly decreased the conduction velocity (from 4.9 ± 1.5 to 2.7 ± 0.7 cm/s; P < 0.05). CCH increased, nifedipine decreased, while TTX had little effect on electrical activities. In addition, a new electrical phenomenon, termed a "patch," was discovered whereby a simultaneous electrical deflection was detected across an area of the bladder surface. Two types of electrical activities were detected on the bladder surface: 1) electrical waves propagating preferentially in the axial direction and 2) electrical patches. The propagating electrical waves could form the basis for local spontaneous contractions in the bladder during the filling phase.

  8. Schirmer tear test, phenol red thread tear test, eye blink frequency and corneal sensitivity in the guinea pig.

    PubMed

    Trost, Katrin; Skalicky, M; Nell, Barbara

    2007-01-01

    To establish reference values for Schirmer tear tests (STT) I and II, phenol red thread (PRT) tear test and eye blink frequency, and to determine corneal sensitivity for normal guinea pigs. One hundred and eight eyes of 54 adult Duncan-Hartley guinea pigs. Schirmer tear test (STT) I and then STT II were performed in 36 guinea pigs. PRT and STT I were compared in 18 adult Duncan-Hartley guinea pigs. Corneal sensitivity was determined in 23 guinea pigs by evaluating the corneal touch threshold (CTT) of five different regions using a Cochet-Bonnet esthesiometer. Eye blink frequency was measured in 10 guinea pigs over a period of 20 min and in 17 guinea pigs over a period of 10 min. Mean STT I was 0.36 mm +/- 1.09 mm (wetting/min) and mean STT II was 0.43 mm +/- 1.29 mm (wetting/min). There was no significant difference between mean STT I and mean STT II (P = 0.79). The mean PRT-value was 16 +/- 4.7 mm (wetting/15 s), and the mean STT I-value in the same guinea pigs was 0.6 +/- 1.83 mm (wetting/min). Corneal sensitivity was significantly higher in the center than in the four limbal regions. The mean CTT for central, ventral, nasal, temporal and dorsal regions was 2, 1.7, 1.7, 1.7 and 1.6 cm or 3.7, 5.2, 5.6, 5.7 and 6.4 g/mm(2), respectively. Eye blink frequency was between two to five (mean 3.4 +/- 1.04) blinks per eye over 20 min in guinea pigs in their home environment, while in handheld and restrained guinea pigs eye blink frequency showed a variation between 0 and 17 blinks per eye (mean 3.24 +/- 3.64 blinks per eye) over 10 min. As there were no significant differences between STT I and STT II results, reflex tear secretion in the guinea pig may not exist. The most likely explanation is a lower corneal sensitivity in the guinea pig than in other species, such as cats, dogs and horses. Because of the small amount of tears, PRT is the preferred test for tear measurement in the guinea pig.

  9. Cell-mediated and humoral immune responses to chlamydial antigens in guinea pigs infected ocularly with the agent of guinea pig inclusion conjunctivitis.

    PubMed

    Senyk, G; Kerlan, R; Stites, D P; Schanzlin, D J; Ostler, H B; Hanna, L; Keshishyan, H; Jawetz, E

    1981-04-01

    Cell-mediated immune response and humoral response to chlamydial antigens were investigated in guinea pigs infected with the agent of guinea pig inclusion conjunctivitis (GPIC). Pronounced cell-mediated immune response to the homologous antigen, as well as to two other chlamydial antigens, 6BC (Chlamydia psittaci) and LB-1 (C. trachomatis), occurred in all infected animals. Cell-mediated immune response to GPIC, and to a lesser extent to 6BC and LB-1 as well, was enhanced with time after infection even without the re-inoculation of the infectious agent. Extensive cross-reactions among the three chlamydial antigens during the cell-mediated immune response appeared to be due to shared species-specific and group-reactive antigens. Serum antibody response was pronounced and uniform to GPIC; it was less marked to 6BC and LB-1, with fewer cross-reactions than seen in tests for cell-mediated immunity.

  10. Effect of estradiol on chlamydial genital infection of female guinea pigs.

    PubMed Central

    Rank, R G; White, H J; Hough, A J; Pasley, J N; Barron, A L

    1982-01-01

    Female guinea pigs were treated daily with 1 mg of beta-estradiol-3-benzoate intramuscularly beginning 14 days before intravaginal inoculation with the chlamydial agent of guinea pig inclusion conjunctivitis and continuing during the course of the infection. Treatment with estradiol was found to markedly influence the course of genital infection with the chlamydial agent of guinea pig inclusion conjunctivitis, producing infections of greater intensity and longer duration than those in control animals. Moreover, pathogenesis was altered in that ascending infection was observed, resulting in endometritis, cystic salpingitis, and cystitis. Infection in the controls was limited to the cervix and vagina. Estradiol treatment increased the apparent number of infected cells in the cervix and vagina as detected by histopathology and immunofluorescent staining. Humoral and cell-mediated immune responses to the chlamydial agent of guinea pig inclusion conjunctivitis were comparable in estradiol-treated and untreated animals. These data indicate that hormonal manipulation may have profound effects on the course of chlamydial genital infections. Images PMID:7141709

  11. Development and duration of BCG-induced allergy in the guinea-pig*

    PubMed Central

    Tolderlund, Knud; Bunch-Christensen, Kirsten; Waaler, Hans

    1960-01-01

    In assessing the biological activity of BCG vaccine by tuberculin testing of vaccinated guinea-pigs, it is necessary to take into account the rates of development and waning of allergy, and also the boosting effect on waning allergy caused by the tuberculin test itself. Using Danish liquid vaccine (in approximately standard dose), the authors have carried out two series of tests, involving more than six hundred guinea-pigs, to evaluate the significance of these factors. Post-vaccination tuberculin sensitivity was found to reach a maximum within 1-2 months. Three months after vaccination the BCG-induced allergy began to wane, and after 12 months it had dropped almost to the level observed in non-vaccinated guinea-pigs. The tuberculin test had a strong boosting effect, however, and even 12 months after vaccination the waning sensitivity could be considerably increased by a single injection of 10 TU of tuberculin. An analysis of the results showed that the waning of the level of allergy takes place gradually over several months. This is not an effect of aging, however, as the response to vaccination was found to be independent of the age of the animals. The indications of this study are that tuberculin testing of guinea-pigs used for the laboratory control of BCG vaccine is best performed about 6 weeks after vaccination. PMID:20604065

  12. Possible formation of nitrosamine in guinea pigs following exposure to nitrogen dioxide and dimethylamine

    SciTech Connect

    Chaudhari, A.; Dutta, S.

    1981-05-01

    The possibility of formation of nitrosamine was investigated in animals exposed to a combination of dimethylamine (DMA) and NO/sub 2/. First, the distribution and covalent binding of DMA and dimethylnitrosamine (DMN) in rats and guinea pigs were determined. The apparent volume of distribution and biological half-life for (/sup 14/C)-DMA or (/sup 14/C) DMN did not reveal any species difference. In general, there were no marked differences in accumulation of radioactivity in tissues of guinea pigs and rats 4 h after the administration of DMA, while the guinea pig tissues showed higher accumulation after DMN administration. Nucleic acid fractions prepared from liver and lungs of both species following administration of DMN or DMA in vivo showed much higher covalent binding with DMN than with DMA. Since guinea pig liver showed a higher degree of covalent binding than rat liver, this species was used to investigate the possible increase in covalent binding in the presence of NO/sub 2/ and DMA as a reflection of DMN formation. There was no evidence of enhancement of covalent binding when animals pretreated with (/sup 14/C)-DMA were exposed for vaious lengths of time to different concentrations of NO/sub 2/.

  13. Antispasmodic effects of Persea cordata bark fractions on guinea pig ileum.

    PubMed

    Cechinel-Filho, Valdir; Zampirolo, Júlio A; Stulzer, Hellen K; Schlemper, Valfredo

    2007-02-01

    The present study describes the antispasmodic activity of some fractions from the bark of Persea cordata, against guinea pig ileum contracted by acetylcholine and histamine. Hexane and dichloromethane fractions demonstrated the most promising biological effects, having similar potency to that of papaverine, a well-known antispasmodic agent.

  14. Combined selenium and vitamin C deficiency causes cell death in guinea pig skeletal muscle.

    PubMed

    Hill, Kristina E; Motley, Amy K; May, James M; Burk, Raymond F

    2009-03-01

    Combined antioxidant deficiencies of selenium and vitamin E or vitamin E and vitamin C in guinea pigs result in clinical illness. We hypothesized that combined selenium and vitamin C deficiency would have clinical consequences because in vitro interactions of these antioxidant nutrients have been reported. Because guinea pigs are dependent on dietary vitamin C, weanling male guinea pigs were fed selenium-deficient or control diet for 15 weeks before imposing vitamin C deficiency. Four dietary groups were formed and studied 3 weeks later: controls, vitamin C deficient, selenium deficient, and doubly deficient. Deficiencies were confirmed by determinations of glutathione peroxidase activity and vitamin C concentration in liver and skeletal muscle. Plasma creatine phosphokinase activity and liver, kidney, heart, and quadriceps histopathology were determined. Doubly deficient animals had moderately severe skeletal muscle cell death as judged by histopathology and plasma creatine phosphokinase activity of 6630 +/- 4400 IU/L (control, 70 + or - 5; vitamin C deficient, 95 + or - 110; selenium deficient, 280 + or - 250). Liver, kidney, and heart histology was normal in all groups. Muscle alpha-tocopherol levels were not depressed in the doubly deficient group, but muscle F2 isoprostane concentrations were elevated in them and correlated with markers of cell death. We conclude that combining selenium and vitamin C deficiencies in the guinea pig causes cell death in skeletal muscle that is more severe than the injury caused by selenium deficiency. The elevation of muscle F2 isoprostanes is compatible with the cell death being caused by oxidative stress.

  15. Development of a guinea pig cutaneous radiation injury model using low penetrating X-rays.

    PubMed

    Rodgers, Kathleen E; Tan, Alick; Kim, Lila; Espinoza, Theresa; Meeks, Christopher; Johnston, William; Maulhardt, Holly; Donald, Melissa; Hill, Colin; diZerega, Gere S

    2016-08-01

    A guinea pig skin model was developed to determine the dose-dependent response to soft X-ray radiation into the dermis. X-ray exposure (50 kVp) was defined to a 4.0 × 4.0 cm area on the lateral surface of a guinea pig using lead shielding. Guinea pigs were exposed to a single fraction of X-ray irradiation ranging from 25-79 Gy via an XRAD320ix Biological Irradiator with the collimator removed. Gross skin changes were measured using clinical assessments defined by the Kumar scale. Skin contracture was assessed, as well as histological evaluations. Loss of dermal integrity was shown after a single dose of soft X-ray radiation at or above 32 Gy with the central 2.0 × 2.0 cm of the exposed site being the most affected. Hallmarks of the skin injury included moist desquamation, ulceration and wound contracture, as well as alterations in epithelium, dermis, muscle and adipose. Changes in the skin were time- and radiation dose-dependent. Full-thickness injury occurred without animal mortality or gross changes in the underlying organs. The guinea pig is an appropriate small animal model for the short-term screening of countermeasures for cutaneous radiation injury (CRI).

  16. [Gallbladder contractility in early stages of lithogenesis in the lithogenic fed guinea pig].

    PubMed

    Lange, K; Gottschalk, M

    1995-07-01

    The main aim of our study was the investigation of gallbladder motility prior to gallstone formation in vivo in guinea pigs fed a lithogenic diet. In a first experiment guinea pigs were fed a lithogenic diet for 5, 15, 30 and 45 days. First gallstones (pigment calculi) appeared after 30 days diet application. The in vitro contractility after lithogenic diet remained unchanged. In a second experimental part the in vivo gallbladder contractility was measured in two experimental animal groups (control group and 21 days lithogenic fed guinea pigs). The isovolumetric pressure rise inside the gallbladder following the intravenous injection of 10(-9) mol/kg body weight ceruletid was the essential contractility parameter (intraluminal basal pressure 5 mm hg). Due to lithogenic feeding of 21 days--that means prior to gallstone formation--the isovolumetric pressure rise was significantly elevated (p < 0.01). Moreover we observed passive distensibility changes of gallbladder muscle due to muscular hyperplasia. The main result of this investigation is the fact that gallbladder muscle in guinea pigs fed a lithogenic diet response to ceruletid application with hypercontractility prior to provable pigment gallstone formation. However gallbladder hypomotility--believed to be a causal factor in cholelithogenesis--was not observed in our experimental conditions.

  17. Evaluation of bioactive glass for mastoid obliteration: a guinea pig model.

    PubMed

    Jang, Chul Ho; Cho, Yong Bum; Bae, Chun Sik

    2007-01-01

    Mastoid obliteration seeks to replace an open mastoid cavity with material that will become viable and free of infection and cholesteatoma. The purpose of this study was to evaluate the efficacy of bioactive glass ceramic particles for mastoid obliteration using a guinea pig animal model. Ten male guinea pigs (weighing 250-300 g) with normal eardrums and Preyer reflexes were used. Bulla obliteration using bioactive glass was performed on the left side in all guinea pigs. The implanted bioactive glass ceramic particles were examined clinically and radiologically by computed tomography (CT) and histologically. Clinically, there were no signs of inflammation, infection or implant exposure in all guinea pigs. The CT scans showed hyperintense areas that represented new bone formation. Histological evidence of new bone formation was observed in the implant specimens that included: active osteoblasts, osteocytes, chondrocytes and osteoid tissue. There was a definite bond between the implant and the bone interface at the areas of new bone formation. No inflammatory or foreign body reactions, caused by the bioactive glass ceramic particle implantation, were observed in the surrounding tissue. Our results suggest that bioactive glass ceramic particles are an ideal implant material. Further studies on bioactive glass ceramic particles should include a larger animal trial to lay the groundwork for human studies.

  18. Human mast cell mediator cocktail excites neurons in human and guinea-pig enteric nervous system.

    PubMed

    Schemann, M; Michel, K; Ceregrzyn, M; Zeller, F; Seidl, S; Bischoff, S C

    2005-04-01

    Neuroimmune interactions are an integral part of gut physiology and involved in the pathogenesis of inflammatory and functional bowel disorders. Mast cells and their mediators are important conveyors in the communication from the innate enteric immune system to the enteric nervous system (ENS). However, it is not known whether a mediator cocktail released from activated human mast cells affects neural activity in the ENS. We used the Multi-Site Optical Recording Technique to image single cell activity in guinea-pig and human ENS after application of a mast cell mediator cocktail (MCMC) that was released from isolated human intestinal mucosa mast cells stimulated by IgE-receptor cross-linking. Local application of MCMC onto individual ganglia evoked an excitatory response consisting of action potential discharge. This excitatory response occurred in 31%, 38% or 11% neurons of guinea-pig submucous plexus, human submucous plexus, or guinea-pig myenteric plexus, respectively. Compound action potentials from nerve fibres or fast excitatory synaptic inputs were not affected by MCMC. This study demonstrates immunoneural signalling in the human gut and revealed for the first time that an MCMC released from stimulated human intestinal mast cells induces excitatory actions in the human and guinea-pig ENS.

  19. COMPARATIVE GENOTOXIC RESPONSES TO ARSENITE IN GUINEA PIG, MOUSE, RAT AND HUMAN LYMPHOCYTES

    EPA Science Inventory

    Comparative genotoxic responses to arsenite in guinea pig, mouse, rat and human
    lymphocytes.

    Inorganic arsenic is a known human carcinogen causing skin, lung, and bladder cancer following chronic exposures. Yet, long-term laboratory animal carcinogenicity studies have ...

  20. THE PREPARATION OF SECTIONS OF GUINEA PIG LIVER FOR ELECTRON MICROSCOPY

    PubMed Central

    Claude, Albert; Fullam, Ernest F.

    1946-01-01

    1. A method is described whereby sections of guinea pig liver cells can be prepared for electron microscopy after fixation. 2. The high resolving powerof the electron microscope reveals the presence of two components, one particulate, the other apparently of fibrous texture, in the ground substance of the cells. PMID:19871546

  1. In vivo evaluation of antiviral efficacy against genital herpes using mouse and guinea pig models.

    PubMed

    Valencia, Frances; Veselenak, Ronald L; Bourne, Nigel

    2013-01-01

    Both the guinea pig and mouse are important animal models for the study of genital herpes. The murine model has been used extensively to evaluate vaccines and antiviral agents by measuring the incidence of infection and the magnitude of viral replication; however, this model is limited with regard to distinguishing between candidate vaccines or treatments. In contrast, the guinea pig closely mimics human infection and provides an excellent model of both primary and recurrent genital herpes disease. This animal model is especially important in the study of viral transmission through the evaluation of latent viral reactivation and virus shedding into the genital tract. Here, we describe methodologies to determine viral infection, severity of primary disease, and quantification of primary viral replication in the genital tract for both the guinea pig and murine models of genital herpes. Additionally, we detail the evaluation of the onset of primary disease and progression to the day of death in the mouse model. Further, we summarize methods to assess the frequency of recurrences, frequency and magnitude of virus shedding, and latent viral load in the sensory nerve ganglia of the guinea pig.

  2. Modeling production functions and economic weights in intensive meat production of guinea pigs.

    PubMed

    Pascual, Mariam; Cruz, Danny Julio; Blasco, Agustín

    2017-06-15

    A profit function for a typical commercial farm of intensive guinea pig production was designed. The simulated farm contained 86 cages with a ratio of 7:1 females/males, with continuous mating. Kits were weaned at 15 days of age and slaughtered for meat production at 90 days of age. The absolute (EW) and relative economic weights of the main traits were calculated. The highest EW were kits produced per kindling (US$25), kits weaned per kindling (US$22), kits born alive per kindling (US$20), and the number of kindlings per female and year (US$12). Profit, returns, and costs per female and year were US$15, 68, and 53, respectively. Returns came from the production of young guinea pigs and discarded reproductive adults for meat production, 90 and 10% of the total returns. The highest costs were feeding and labor, 44 and 23% of the total cost. The EW and profit did not substantially change when simulating variations of ±20% in the prices of kilograms of fattening feed and kilograms of live weight of guinea pig, showing their robustness to future variations in market prices or to variations in prices between countries. The results obtained highlight the importance of the feeding costs in the guinea pig meat production.

  3. Effects of disodium cromoglycate (DSCG) on the guinea pig trachea and ileum.

    PubMed

    González Alvarez, R; Arruzazabala, M L

    1983-01-01

    Disodium cromoglycate (DSCG) (10(-2)M) significantly inhibits contractions induced by potassium chloride and barium chloride on guinea pig ileum and trachea. The effects of DSCG against these spasmogens are greater on the guinea pig ileum than on its trachea, which may be related with the calcium ion if we take into account that the contraction of the latter preparation seems to be less dependent on the extracellular calcium concentration than the first one. DSCG (10(-2)M) inhibits contractions induced by electrical stimulation (0.1 Hz) but the action of exogenous acetylcholine is not affected. This effect supports a neural site of action for DSCG in the ileum. DSCG (10(-2)M) also suppresses contractions induced by electrical stimulation (20 Hz) on isolated guinea pig trachea. This effect of DSCG is concentration and time dependent. The fact that DSCG inhibits contractions induced by electrical stimulation in both, guinea pig ileum and trachea as well as atropine does, constitute evidence that either an inhibition of acetylcholine release from postganglionic parasympathetic fibers or an anticholinergic effect is involved in the mode of action of DSCG. These effects can be ascribed to membrane stabilizing properties of this antiallergic drug.

  4. Cutaneous Uptake of 14C-HD Vapor by the Hairless Guinea Pig.

    DTIC Science & Technology

    1996-10-01

    The hairless guinea pig ( HGP ) is used by our laboratory to model the human cutaneous response to sulfur mustard (HD) exposure. We have determined the...other aspects of the experimental model. These results contribute to a better understanding of the cutaneous response to HD in the HGP model.

  5. Endogenous histamine and promethazine-induced gastric ulcers in the guinea pig

    NASA Technical Reports Server (NTRS)

    Djahanguiri, B.; Hemmati, M.

    1978-01-01

    Experiments performed with an inhibitor of diaminoxydase, aminoguanidine and an inhibitor of histidine decarboxylase, NSD 1055, showed that the frequency of gastric ulcers induced by promethazine was increased with the first inhibitor and decreased with the second. It is suggested that ulcers induced by promethazine in guinea pigs might be due to histamino-liberator effect of the antihistaminio compound.

  6. Contractile properties of synthetic cationic polypeptides in guinea-pig isolated trachea.

    PubMed Central

    Spina, D.; Goldie, R. G.

    1994-01-01

    1. The synthetic polypeptides, poly-L-arginine, poly-L-lysine and poly-D-lysine contract guinea-pig isolated trachea in a concentration-dependent, epithelium-independent manner. Indomethacin augmented the contractile response to poly-L-arginine. 2. The contractile response to poly-L-arginine was not significantly inhibited by nicardipine, a selective L-type calcium channel blocker or by the histamine H1-receptor antagonist, mepyramine nor significantly augmented by the neutral endopeptidase inhibitor, phosphoramidon. 3. The contractile response to poly-L-arginine was inhibited in a concentration-dependent manner by prior incubation of guinea-pig tracheal rings with a number of anionic polypeptides including, low molecular weight heparin, poly-L-aspartic acid and bovine serum albumin. 4. In vitro capsaicin-induced desensitization failed to attenuate the contractile response to poly-L-arginine, suggesting little, if any role for sensory neuropeptides in the functional response in the guinea-pig. 5. Synthetic polypeptides induce an epithelium-independent, charge-dependent contraction of guinea-pig isolated trachea. PMID:8012709

  7. Combined Selenium and Vitamin C Deficiency Causes Cell Death in Guinea Pig Skeletal Muscle1

    PubMed Central

    Hill, Kristina E.; Motley, Amy K.; May, James M.; Burk, Raymond F.

    2009-01-01

    Combined antioxidant deficiencies of selenium and vitamin E or vitamin E and vitamin C in guinea pigs result in clinical illness. We hypothesized that combined selenium and vitamin C deficiency would have clinical consequences because in vitro interactions of these antioxidant nutrients have been reported. Since guinea pigs are dependent on dietary vitamin C, weanling male guinea pigs were fed selenium-deficient or control diet for 15 weeks prior to imposing vitamin C deficiency. Four dietary groups were formed and studied 3 weeks later: controls, vitamin C deficient, selenium deficient, and doubly deficient. Deficiencies were confirmed by determinations of glutathione peroxidase activity and vitamin C concentration in liver and skeletal muscle. Plasma creatine phosphokinase (CPK) activity and liver, kidney, heart, and quadriceps histopathology were determined. Doubly deficient animals had moderately severe skeletal muscle cell death as judged by histopathology and plasma CPK activity of 6630 ± 4400 IU/L (control 70 ± 5; vitamin C deficient 95 ± 110; selenium deficient 280 ± 250). Liver, kidney, and heart histology was normal in all groups. Muscle α-tocopherol levels were not depressed in the doubly deficient group but muscle F2 isoprostane concentrations were elevated in them and correlated with markers of cell death. We conclude that combining selenium and vitamin C deficiencies in the guinea pig causes cell death in skeletal muscle that is more severe than the injury caused by selenium deficiency. The elevation of muscle F2 isoprostanes is compatible with the cell death being caused by oxidative stress. PMID:19358936

  8. Diet Restriction and Fasting Exacerbate the Toxicity of Soman in Young and Old Guinea Pigs

    DTIC Science & Technology

    2012-09-01

    young and old guinea pigs Todd M . Myers Jeffrey L. Langston September 2012 Approved for public release; distribution...PAGES 19a. NAME OF RESPONSIBLE PERSON Todd M . Myers a. REPORT UNCLASSIFIED b. ABSTRACT UNCLASSIFIED c. THIS PAGE UNCLASSIFIED Unlimited 20...clip ( Vallejo -Freire, 1951) prior to soman or saline administration (at minus 1 week and at 0 h) and analyzed for acetylcholinesterase

  9. Synthesis by guinea pig megakaryocytes of platelet glycoprotein receptors for fibrinogen and von Willebrand factor.

    PubMed

    Kupinski, J M; Miller, J L

    1986-08-01

    In the preceding paper, we described two monoclonal antibodies, PG-1 and PG-2, that selectively blocked the binding of von Willebrand factor (PG-1) or of fibrinogen (PG-2) to guinea pig platelets. In this study we examine the structures and site of synthesis of these receptors. NP-40 lysates of radiolabeled guinea pig platelets were immunoprecipitated with monoclonal antibodies PG-1 or PG-2, and the precipitates analyzed by SDS-PAGE. PG-1 recognized a single polypeptide with reduced Mr of 143,000 daltons, while PG-2 precipitated two chains with reduced Mr of 121,000 and 93,000 daltons. Periodate-[3H]borohydride labeling of platelets, in conjunction with two-dimensional SDS-PAGE, showed that all three of the polypeptides are glycoproteins and that the 143,000 and 121,000 dalton chains are linked by disulfide bond(s) to smaller, approximately 25,000 dalton polypeptides. Guinea pig megakaryocytes synthesized polypeptides immunoprecipitable by PG-1 and PG-2, with molecular weights similar to polypeptides found associated with platelet membranes. These studies demonstrate that guinea pig platelets have functional receptors for fibrinogen and von Willebrand factor that are structurally homologous to human platelet glycoproteins Ib, IIb and IIIa, and that these glycoproteins are synthesized by megakaryocytes.

  10. The in vitro isolated whole guinea pig brain as a model to study epileptiform activity patterns.

    PubMed

    de Curtis, Marco; Librizzi, Laura; Uva, Laura

    2016-02-15

    Research on ictogenesis is based on the study of activity between seizures and during seizures in animal models of epilepsy (chronic condition) or in in vitro slices obtained from naïve non-epileptic brains after treatment with pro-convulsive drugs, manipulations of the extracellular medium and specific stimulation protocols. The in vitro isolated guinea pig brain retains the functional connectivity between brain structures and maintains interactions between neuronal, glial and vascular compartments. It is a close-to-in vivo preparation that offers experimental advantages not achieved with the use of other experimental models. Neurophysiological and imaging techniques can be utilized in this preparation to study brain activity during and between seizures induced by pharmacological or functional manipulations. Cellular and network determinants of interictal and ictal discharges that reproduce abnormal patterns observed in human focal epilepsies and the associated changes in extracellular ion and blood-brain permeability can be identified and analyzed in the isolated guinea pig brain. Ictal and interictal patterns recorded in in vitro slices may show substantial differences from seizure activity recorded in vivo due to slicing procedure itself. The isolated guinea pig brain maintained in vitro by arterial perfusion combines the typical facilitated access of in vitro preparations, that are difficult to approach during in vivo experiments, with the preservation of larger neuronal networks. The in vitro whole isolated guinea pig brain preparation offers an unique experimental model to study systemic and neurovascular changes during ictogenesis. Published by Elsevier B.V.

  11. Effects of ozone and sulfuric acid aerosol on gas trapping in the guinea pig lung

    SciTech Connect

    Silbaugh, S.A.; Mauderly, J.L.

    1986-01-01

    Four groups of 20 guinea pigs were sequentially exposed by inhalation to either air followed by sulfuric acid aerosol, ozone followed by sulfuric acid aerosol, ozone followed by air, or air followed by air to determine whether ozone preexposure sensitizes guinea pigs to the airway constrictive effects of sulfuric acid aerosol. All first exposures to ozone or air were 2 h in duration; all second exposures to sulfuric acid or air were for 1 h. All ozone and sulfuric acid exposures were 0.8 ppm and 12 mg/m3, respectively. Animals were observed for respiratory distress during exposure, and excised lungs were quantitated for trapped gas and wet/dry ratios. None of the guinea pigs developed dyspnea, and wet/dry ratios were not altered. Ozone significantly (p less than 0.05) increased trapped gas volumes, which were 44% (ozone-acid) to 68% (ozone-air) greater than in the air-air group. Trapped gas volume was 23% greater in the ozone-acid group than in the air-acid group, but the difference was not statistically significant (p less than 0.20). Thus, ozone increased gas trapping but did not significantly sensitize guinea pigs to the bronchoconstrictive action of sulfuric acid.

  12. Effect of systemic clarithromycin and prednisolone on histamine-induced otitis media in guinea pigs.

    PubMed

    Kozan, Günay; Aktan, Bülent; Sakat, Muhammed Sedat; Kurt, Sezgin; Öner, Fatih; Kara, Adem

    2015-01-01

    The results of the study showed that clarithromycin has anti-inflammatory and antioxidant effects and, when it is combined with prednisolone, those effects gain strength. The present study aims to investigate the effects that the antioxidant and anti-inflammatory activities of clarithromycin and/or prednisolone have on experimental otitis media in effusion-induced guinea-pigs. In this study, 35-male guinea pigs were randomly divided into five-groups. For the experimental otitis media, intra-tympanic histamine (0.1 ml) was injected into the guinea pigs in all of the groups except the control group. Then, 24-h after the intra-tympanic injections, clarithromycin (15 mg/kg/day) and/or prednisolone (1 mg/kg/day) were applied intraperitoneally to the guinea-pigs for 7-days. The biochemical analysis showed an increase in antioxidant capacity and a decrease in oxidant status and malondialdehyde (MDA) levels in the clarithromycin group and the prednisolone group and especially in the clarithromycin+prednisolone group, as compared to the experimental group (p < 0.05). In the cytokine analysis, lower levels of interleukin (IL)-6 and IL-17A and higher IL-10 were found in the clarithromycin, prednisolone, and clarithromycin+prednisolone groups than in the experimental group (p < 0.05). Furthermore, the histologic analyses showed histopathologic changes in the middle ear mucosa of the experimental group, but comparatively fewer-histopathologic changes were observed in the clarithromycin, prednisolone, and clarithromycin+prednisolone groups.

  13. THE IMPACT OF ULTRAVIOLET IRRADIATION ON MORPHO-FUNCTIONAL STATE OF SKIN IN GUINEA PIGS.

    PubMed

    Myronchenko, S; Naumova, O; Zvyagintseva, T

    2016-11-01

    The purpose of this study was to assess the impact of ultraviolet irradiation (UV) on morphological and functional condition of the skin in guinea pigs. The study involved 30 albino guinea pigs weighing 400-500 g subjected to local exposure to UV irradiation. Control group consisted of intact guinea pigs. Histological studies of the skin were carried out at different stages of the trial (2 hours, 4 hours, 3 days, 8 days following the exposure). Microscopic examination showed morphological signs of acute inflammation in the skin of animals within the first three days following the exposure to UV irradiation. Within 2 hours following the exposure to UV irradiation these changes were minimal with signs of mild exudative changes. In 4 hours after the exposure histological changes increased. The specimens were also found to contain altered apoptotic keratinocytes (sunburn cells). Histopathological changes persisted and reached maximum severity by the 3rd day. Within post-erythema period (the 8th day) proliferative, hyperplastic, degenerative and dystrophic changes in the skin persisted. The prolonged nature of the changes in the skin is suggestive of the development of chronic inflammation in the skin of guinea pigs subjected to local exposure to UV irradiation.

  14. Mitochondria-Targeted Antioxidant Mitoquinone Reduces Cisplatin-Induced Ototoxicity in Guinea Pigs.

    PubMed

    Tate, Alan D; Antonelli, Patrick J; Hannabass, Kyle R; Dirain, Carolyn O

    2017-03-01

    Objective To determine if mitoquinone (MitoQ) attenuates cisplatin-induced hearing loss in guinea pigs. Study Design Prospective and controlled animal study. Setting Academic, tertiary medical center. Subjects and Methods Guinea pigs were injected subcutaneously with either 5 mg/kg MitoQ (n = 9) or normal saline (control, n = 9) for 7 days and 1 hour before receiving a single dose of 10 mg/kg cisplatin. Auditory brainstem response thresholds were measured before MitoQ or saline administration and 3 to 4 days after cisplatin administration. Results Auditory brainstem response threshold shifts after cisplatin treatment were smaller by 28 to 47 dB in guinea pigs injected with MitoQ compared with those in the control group at all tested frequencies (4, 8, 16, and 24 kHz, P = .0002 to .04). Scanning electron microscopy of cochlear hair cells showed less outer hair cell loss and damage in the MitoQ group. Conclusion MitoQ reduced cisplatin-induced hearing loss in guinea pigs. MitoQ appears worthy of further investigation as a means of preventing cisplatin ototoxicity in humans.

  15. Effect of ozone exposure on antigen-induced airway hyperresponsiveness in guinea pigs

    SciTech Connect

    Vargas, M.H.; Segura, P.; Campos, M.G.; Hong, E.; Montano, L.M.

    1994-12-31

    Airway hyperresponsiveness can be induced by several stimuli including antigen and ozone, both of which may be present in the air of polluted cities. Though the effect of ozone on the bronchoconstrictor response to antigen has been well described, the combined effect of these stimuli on airway hyperresponsiveness has not yet been studied. Sensitized guinea pigs with or without ozone exposure for 1 h at 3 ppm, 18 h prior to study, were challenged with a dose-response curve to histamine (0.01-1.8 {mu}g/kg, iv), and then by a second histamine dose-response curve 1 h later. Airway responses were measured as the increase in pulmonary insufflation pressure. In sensitized guinea pigs, the histamine ED50 significantly decreased after antigen challenge, demonstrating the development of airway hyperresponsiveness. Sensitized guinea pigs exposed to ozone showed airway hyperresponsiveness to histamine when compared with nonexposed animals, and such hyperresponsiveness was further enhanced after antigen challenge. We conclude that in this guinea pig model of acute allergic bronchoconstriction both antigen challenge and ozone induce airway hyperresponsiveness, while ozone exposure does not modify the development of antigen-induced hyperresponsiveness. 25 refs., 1 fig., 1 tab.

  16. Effect of estradiol on chlamydial genital infection of female guinea pigs.

    PubMed

    Rank, R G; White, H J; Hough, A J; Pasley, J N; Barron, A L

    1982-11-01

    Female guinea pigs were treated daily with 1 mg of beta-estradiol-3-benzoate intramuscularly beginning 14 days before intravaginal inoculation with the chlamydial agent of guinea pig inclusion conjunctivitis and continuing during the course of the infection. Treatment with estradiol was found to markedly influence the course of genital infection with the chlamydial agent of guinea pig inclusion conjunctivitis, producing infections of greater intensity and longer duration than those in control animals. Moreover, pathogenesis was altered in that ascending infection was observed, resulting in endometritis, cystic salpingitis, and cystitis. Infection in the controls was limited to the cervix and vagina. Estradiol treatment increased the apparent number of infected cells in the cervix and vagina as detected by histopathology and immunofluorescent staining. Humoral and cell-mediated immune responses to the chlamydial agent of guinea pig inclusion conjunctivitis were comparable in estradiol-treated and untreated animals. These data indicate that hormonal manipulation may have profound effects on the course of chlamydial genital infections.

  17. Experimental Chagas' disease in complement-deficient mice and guinea pigs.

    PubMed Central

    Dalmasso, A P; Jarvinen, J A

    1980-01-01

    The course of infection with trypomastigotes of Trypanosoma cruzi (House 510 strain) in mice and guinea pigs with genetic complement deficiencies was compared with that in normocomplementemic animals. Parasitemias in a mouse strain (B10.D2/old) genetically deficient in C5 and therefore unable to sustain lysis were similar to or lower than in a congenic normocomplementemic strain (B10.D2/new). The levels of C3 measured immunochemically were generally unaffected. There were no significant differences in mortality rates. These results indicate that, in mice, complement-mediated lysis does not play a significant role in the control of T. cruzi (House 510) infections. Studies were also performed in normocomplementemic guinea pigs and in guinea pigs genetically deficient in the fourth component of complement and thus unable to support functions mediated by the classical pathway of complement activation. No significant differences were noted between the two strains in the course of infection, persistence of subpatent infection, or rate of mortality, indicating that if the classical complement pathway plays a role in resistance to T. cruzi (House 510) in guinea pigs, this role must be a small one. PMID:6772558

  18. Effects of chronic ascorbic acid deficiency on guinea pig lysosomal hydrolase activities.

    PubMed

    Hoehn, S K; Kanfer, J N

    1980-10-01

    Previously we have observed increased specific activities of several lysosomal hydrolases in scorbutic guinea pigs and thus the specificity of this effect was examined in guinea pigs marginally deficient in ascorbic acid (AA). Guinea pigs were fed an AA-deficient diet for 2 weeks to deplete body AA pools and then fed a stock diet containing 0.5 mg AA/g diet or the deficient diet plus oral administration of 10 mg AA/day, 1 mg AA/100 g body weight or 0.5 mg AA/100 g body weight each day. Animal were periodically killed during the 12-week experiment and lysosomes isolated from individual livers and analyzed. Serum and brain AA declined when AA was withheld, returned to normal when the stock diet or 10 mg AA were fed but remained at low levels on administation of 1.0 mg or 0.5 mg AA/100 g body weight. Brain norepinephrine followed a similar pattern to brain AA and was opposite to the pattern observed for dopamine. In guinea pigs receiving 1 mg AA/100 g body weight, amine concentrations slowly returned to normal after 8 weeks. Serum hexosaminidase and lysosomal cathepsins A and B were unchanged during the experiment, whereas lysosomal hexosaminidase and acid phosphatase were significantly higher when the experiment was terminated.

  19. Morphological analysis of the vestibular system of guinea pigs poisoned by organophosphate.

    PubMed

    Cogo, Lícia Assunção; Santos Filha, Valdete Alves Valentins dos; Murashima, Adriana de Andrade Batista; Hyppolito, Miguel Angelo; Silveira, Aron Ferreira da

    2016-01-01

    The vestibular system is responsible for body balance. There are substances that damage it, causing dizziness; these are termed vestibulotoxic substances. Agrochemicals have been investigated for ototoxicity because of studies that identified dizziness as a recurrent symptom among rural workers' complaints. To histopathologically evaluate the vestibular system in guinea pigs exposed to an organophosphate, and to identify the drug's effects on this system. Experimental clinical study. Eighteen guinea pigs were used; six of them poisoned with the organophosphate chlorpyrifos at doses of 0.5mg/kg/day and seven of them at 1mg/kg/day; and a control group of five guinea pigs was exposed to distilled water, all for 10 consecutive days. Later, ciliary tufts of saccule and utricle maculae were counted by scanning electron microscopy. Comparing the groups, a one-way ANOVA test for the variable "saccule" (p=0.0569) and a Kruskal-Wallis test for the variable "utricle" (p=0.8958) were performed, revealing no difference amo