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Sample records for guinea pig cavia

  1. 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

  2. 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.

  3. Experimental poisoning of guinea pig (Cavia porcellus) with Indigofera suffruticosa.

    PubMed

    Salvador, I S; Medeiros, R M T; Pessoa, C R M; Oliveira, D M; Duarte, A L A; Fighera, R A; Riet-Correa, F

    2011-05-01

    Indigofera suffruticosa causes hemolytic anemia and hemoglobinuria in cattle. The plant was administered to six groups of two guinea pigs each, at the daily dose of 10 g/kg body weight, for periods of 2, 4, 6, 8, 10 and 15 days. The guinea pigs progressively developed reduced hematocrits and hemoglobin concentrations, and finally presented anemia, without hemoglobinuria. Urine passed by guinea pigs that had ingested the plant for more than 24 h acquired a turquoise blue pigmentation 8-10 h after urination. It is suggested that the anemia is caused by the aniline contained in I. suffruticosa.

  4. Experimental poisoning of guinea pig (Cavia porcellus) with Indigofera suffruticosa.

    PubMed

    Salvador, I S; Medeiros, R M T; Pessoa, C R M; Oliveira, D M; Duarte, A L A; Fighera, R A; Riet-Correa, F

    2011-05-01

    Indigofera suffruticosa causes hemolytic anemia and hemoglobinuria in cattle. The plant was administered to six groups of two guinea pigs each, at the daily dose of 10 g/kg body weight, for periods of 2, 4, 6, 8, 10 and 15 days. The guinea pigs progressively developed reduced hematocrits and hemoglobin concentrations, and finally presented anemia, without hemoglobinuria. Urine passed by guinea pigs that had ingested the plant for more than 24 h acquired a turquoise blue pigmentation 8-10 h after urination. It is suggested that the anemia is caused by the aniline contained in I. suffruticosa. PMID:21396390

  5. 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. PMID:21090891

  6. 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.

  7. 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

  8. 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

  9. 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

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

    PubMed

    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.

  11. Characterization of fetal growth by repeated ultrasound measurements in the wild guinea pig (Cavia aperea).

    PubMed

    Schumann, K; Guenther, A; Göritz, F; Jewgenow, K

    2014-08-01

    Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P < 0.001) other and with gestational age (BPD regression equation y = 0.04x - 0.29; P < 0.001 and CRL regression equation y = 0.17x - 2.21; P < 0.01). Furthermore, fetuses in the most frequent uterine positions did not differ in their growth parameters and were not influenced by the mother ID. Our results imply that ultrasound measurement of a single fetal growth parameter is sufficient to reliably estimate gestational age in the wild guinea pig.

  12. Bitter avoidance in Guinea Pigs (Cavia porcellus) and Mice (Mus musculus and Peromyscus leucopus)

    PubMed Central

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

    2010-01-01

    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 non-herbivorous mouse species (Mus musculus and Peromyscus leucopus). Guinea pigs did show weaker avoidance of QHCl 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. PMID:21090891

  13. 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.

  14. 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

  15. 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.

  16. Female novelty and the courtship behavior of male guinea pigs (Cavia porcellus).

    PubMed

    Cohn, D W H; Tokumaru, R S; Ades, C

    2004-06-01

    In several rodent species, an increase or recovery of sexual behavior can be observed when sexually satiated males are placed in contact with a novel mate. In order to assess the influence of female novelty on the courtship behavior of guinea pigs (Cavia porcellus), four adult males were observed during four daily 15-min sessions while interacting with the same pregnant female (same-female sessions). A new female was presented during the fifth session (switched-female session). The duration of behavioral categories was obtained from videotape records using an observational software. From the first to the second session, all males decreased the time allocated to investigating (sniffing and licking), following, and mounting the female, and that response did not recover by the end of the same-female sessions. No similar decreasing tendencies were detected in the circling or rumba categories. A marked increase of investigating occurred in all males from the last same-female session (8.1, 11.9, 15.1 and 17.3 percent session time) to the switched-female one (16.4, 18.4, 37.1 and 28.9 percent session time, respectively). Increases in following and circling were recorded in three of four males, and full-blown recovery of mounting in one male. No consistent changes in the females' responses to males (following or attacking) were observed throughout testing. These results are consistent with the hypothesis that guinea pig males recognize individual females and that courtship responses may suffer a habituation/recovery process controlled by mate novelty.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  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. 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. PMID:25517408

  5. 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

  6. 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.

  7. 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

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

    PubMed Central

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

    2015-01-01

    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. PMID:26632788

  9. 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. PMID:26632788

  10. 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

  11. 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. PMID:27423156

  12. Enriched open field facilitates exercise and social interaction in 2 strains of guinea pigs (Cavia porcellus).

    PubMed

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

    2014-07-01

    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.

  13. 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

  14. 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. PMID:25051197

  15. 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

  16. 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.

  17. Ultrasound-guided percutaneous antegrade hydropropulsion to relieve ureteral obstruction in a pet guinea pig (Cavia porcellus)

    PubMed Central

    Eshar, David; Lee-Chow, Bridget; Chalmers, Heather J.

    2013-01-01

    Severe hydroureter and hydronephrosis secondary to ureteral obstruction by calculus were present in a guinea pig. A palliative ultrasound-guided percutaneous antegrade hydropropulsion was performed under general anesthesia to relieve the ureteral obstruction and the associated clinical signs. We describe the technique and the considerations for its potential application in similar cases. PMID:24293674

  18. 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

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

    PubMed

    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

  20. Comparison of tympanic, transponder, and noncontact infrared laser thermometry with rectal thermometry in strain 13 guinea pigs (Cavia porcellus).

    PubMed

    Stephens Devalle, Julie M

    2005-09-01

    The purpose of this experiment was to assess the practicality, ease, and reliability of using tympanic, transponder, and noncontact infrared laser thermometry versus rectal thermometry in strain 13 guinea pigs. Body temperatures were measured by all four methods within each animal over 10 min, and three sets of measurements were taken over 2 days. Each method was compared for agreement over time and agreement with the rectal temperature of each animal. Over time the transponder temperatures were the most reliable and had the closest agreement with the rectal temperatures. There was an overall difference in mean temperatures among methods but not between times, indicating that the guinea pigs had stable body temperatures over different time periods. Although the mean temperatures from the transponder and tympanic thermometers were not significantly different from the rectal temperatures, only the transponder method was in close agreement with the rectal method. The tympanic and noncontact infrared laser methods had poor agreement with the rectal method. These study results suggest that transponder thermometry is an easy and accurate alternative to rectal thermometry in strain 13 guinea pigs.

  1. Chronic stress in pregnant guinea pigs (Cavia aperea f. porcellus) attenuates long-term stress hormone levels and body weight gain, but not reproductive output.

    PubMed

    Schöpper, Hanna; Palme, Rupert; Ruf, Thomas; Huber, Susanne

    2011-12-01

    Stress, when extreme or chronic, can have a negative impact on health and survival of mammals. This is especially true for females during reproduction when self-maintenance and investment in offspring simultaneously challenge energy turnover. Therefore, we investigated the effects of repeated stress during early- and mid-gestation on the maternal stress axis, body weight gain and reproductive output. Female guinea pigs (Cavia aperea f. porcellus, n = 14) were either stressed (treatment: exposure to strobe light in an unfamiliar environment on gestational day -7, 0, 7, 14, 21, 28, 35, 42) or left completely undisturbed (control) throughout pregnancy. Females of both groups received the same respective diets, and reproductive parameters were evaluated upon parturition. Additionally, hormonal data were obtained from blood and feces. The stress exposure induced a significant increase in plasma cortisol concentrations during the afternoon. In contrast to this short-term response in plasma cortisol concentrations, we found no significant differences in the levels of cortisol metabolites in feces collected after stress exposure between groups and even significantly decreased levels of fecal cortisol metabolites on non-stress days over time in treatment females. Among treatment females, gain in body weight was attenuated over gestation and body weight was lower compared to control females during lactation, especially in cases of large litter sizes. No differences could be seen in the reproductive parameters. We conclude that repeated stress exposure with strobe light during early- and mid-gestation results in a down-regulation of the hypothalamic-pituitary-adrenal axis and lower weight gain in treatment females, but has no effect on reproductive output. PMID:21647601

  2. 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

  3. 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.

  4. 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

  5. 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. PMID:26181690

  6. 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.

  7. 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

  8. Survey of endoparasites in pet guinea pigs in Italy.

    PubMed

    d'Ovidio, Dario; Noviello, Emilio; Ianniello, Davide; Cringoli, Giuseppe; Rinaldi, Laura

    2015-03-01

    Little information is available on the occurrence of endoparasites in pet guinea pigs (Cavia porcellus). The purpose of this study was to evaluate the prevalence of intestinal parasites in cavies kept as pets in southern Italy. Fresh fecal samples were randomly collected from 60 guinea pigs housed in pet shops or privately owned. All fecal samples were processed using the FLOTAC pellet technique to identify and count helminthic eggs/larvae and protozoan cysts/oocysts. In addition, the specimens were analyzed also by the Remel Xpect® Giardia/Cryptosporidium immunoassay. Intestinal parasites were detected in 19 out of 60 guinea pigs (31.7 %). Paraspidodera uncinata eggs were found in 13.3 % (8/60) of the rodents examined, Nippostrongylus-like eggs in 10 % (6/60), and finally Eimeria caviae oocysts were found in 10 % (6/60) of the animals. In one case, both E. caviae oocysts and P. uncinata eggs were found. None of the samples was positive for Cryptosporidium or Giardia. To the authors' knowledge, this is the first survey of endoparasites in pet guinea pigs in Italy.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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....

  10. Chlamydiales in guinea-pigs and their zoonotic potential.

    PubMed

    Lutz-Wohlgroth, L; Becker, A; Brugnera, E; Huat, Z L; Zimmermann, D; Grimm, F; Haessig, M; Greub, G; Kaps, S; Spiess, B; Pospischil, A; Vaughan, L

    2006-05-01

    The aim was to detect and characterize chlamydial infections in guinea-pigs (GP) with ocular disease, study their pathogenicity and zoonotic potential and to test for the presence of Acanthamoebae spp. in GP eyes and to investigate whether they could act as vectors for Chlamydia-like organisms. Overall 126 GP, of which 77 were symptomatic, were screened by clinical examination, cytology, gross pathology, histology, immunohistochemistry, polymerase chain reaction (PCR) and bacteriology. A new Chlamydiaceae-specific intergenic spacer rRNA gene PCR, designed to amplify this segment linking the 16S and 23S regions, was performed. DNA samples were also received from one owner including samples of his cat and rabbit. Guinea-pigs: 48 of 75 symptomatic, but only 11 of 48 asymptomatic GP were positive by PCR for Chlamydophila caviae guinea-pig inclusion conjunctivitis (GPIC) (P < 0.0001). Eighteen of 75 or 15/48, respectively, were positive for DNA from Chlamydia-like organisms. Acanthamoebae-DNA could be found in two GP, of which one was symptomatic. Owner, cat and rabbit: Samples of all three species were positive by PCR for C. caviae GPIC and the owner's one-day disposable contact lenses showed a positive PCR result for the Chlamydia-like organism Parachlamydia acanthamoebae. No Acanthamoebae-DNA could be detected. This study is the first to describe Chlamydia-like organisms in GP and to detect C. caviae GPIC in human, cat and rabbit. Therefore, C. caviae GPIC could pose a zoonotic potential. We believe that the finding of C. caviae GPIC in species other than GP is probably not unique.

  11. 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

  12. An ecologically relevant guinea pig model of fetal behavior.

    PubMed

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

    2015-04-15

    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 multicolored Hartley males were observed longitudinally without restraint using noninvasive ultrasound at weekly intervals across the 10 week gestation. To ensure 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

  13. An ecologically relevant guinea pig model of fetal behavior.

    PubMed

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

    2015-04-15

    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 multicolored Hartley males were observed longitudinally without restraint using noninvasive ultrasound at weekly intervals across the 10 week gestation. To ensure 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.

  14. Guinea pig models of asthma.

    PubMed

    McGovern, Alice E; Mazzone, Stuart B

    2014-01-01

    Described in this unit are methods for establishing guinea pig models of asthma. Sufficient detail is provided to enable investigators to study bronchoconstriction, cough, airway hyperresponsiveness, inflammation, and remodeling. PMID:25446291

  15. 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.

  16. 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

  17. 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

  18. Coccidiosis in guinea-pigs.

    PubMed

    Ellis, P A; Wright, A E

    1961-07-01

    The attention of laboratory workers is drawn to the possibility of coccidiosis as a cause of death in guinea-pigs. The purchase of a number of guinea-pigs infected with this protozoon was followed by 12 deaths when these animals were injected with material for diagnostic purposes. No deaths occurred in the laboratory stock herd, as these were kept separate from the newcomers and were not infected. The life history of the parasite is described, together with the post-mortem findings in our series of animals.

  19. 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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  20. Digesta retention and fibre digestion in maras (Dolichotis patagonum) and guinea-pigs.

    PubMed

    Sakaguchi, E; Nippashi, K; Endoh, G

    1992-04-01

    1. Digestibilities of feed and turnover time (1/k), transit time (TT) and mean retention time (MRT: 1/k+TT) of fluid and particle markers were measured in maras (Dolichotis patagonum) and guinea-pigs (Cavia procellus) fed a diet containing 50% alfalfa. 2. The digestibility of fibre was similar in both animals, however, the digestibilities of crude protein (nitrogen x 6.25) and crude ash were lower in the mara than in the guinea-pig. 3. 1/k of the digesta markers were similar in both animals, suggesting that the two animals possess similar dilution and retention time of digesta in their caecum and proximal colon. PMID:1351463

  1. 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. PMID:26139838

  2. 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.

  3. 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.

  4. 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)

  5. Isolation and characterization of Guinea pig properidin.

    PubMed

    Nicholson, A; Austen, K F

    1977-01-01

    Guinea pig properdin was purified to homogeneity by employing as an assay during isolation its capacity to augment the hemolytic activity of a heterologous human C3b-dependent C3 convertase, C3B. The purified protein elicited a monospecific antibody response in a rabbit. The antiserum, by immunodiffusion, gave a reaction of identity between a protein in whole guinea pig serum and the immunogen. A solid phase immunoadsorbent prepared with the antiserum removed properdin function from the purified protein. The purified guinea pig protein exhibited the classical properdin function of reconstituting a human RP for zymosan-induced C3 inactivation. The guinea pig properdin also agglutinated red cell intermediates bearing either guinea pig or human C3b and retarded the decay of homologous C3 convertase, C3B. These activities are the same as those observed for purified human properdin and validate the amplification function of properdin on terminal component activation in a second species.

  6. Endocrine tumours in the guinea pig.

    PubMed

    Künzel, Frank; Mayer, Jörg

    2015-12-01

    Functional endocrine tumours have long been thought to be rare in guinea pigs, although conditions such as hyperthyroidism and hyperadrenocorticism have been documented with increasing frequency so the prevalence of hormonal disorders may have been underestimated. Both the clinical signs and diagnosis of hyperthyroidism in guinea pigs appear to be very similar to those described in feline hyperthyroidism, and methimazole has been proven to be a practical therapy option. Hyperadrenocorticism has been confirmed in several guinea pigs with an adrenocorticotropic hormone stimulation test using saliva as a non-invasive sample matrix; trilostane has been successfully used to treat a guinea pig with hyperadrenocorticism. Insulinomas have only rarely been documented in guinea pigs and one animal was effectively treated with diazoxide. PMID:26542368

  7. Endocrine tumours in the guinea pig.

    PubMed

    Künzel, Frank; Mayer, Jörg

    2015-12-01

    Functional endocrine tumours have long been thought to be rare in guinea pigs, although conditions such as hyperthyroidism and hyperadrenocorticism have been documented with increasing frequency so the prevalence of hormonal disorders may have been underestimated. Both the clinical signs and diagnosis of hyperthyroidism in guinea pigs appear to be very similar to those described in feline hyperthyroidism, and methimazole has been proven to be a practical therapy option. Hyperadrenocorticism has been confirmed in several guinea pigs with an adrenocorticotropic hormone stimulation test using saliva as a non-invasive sample matrix; trilostane has been successfully used to treat a guinea pig with hyperadrenocorticism. Insulinomas have only rarely been documented in guinea pigs and one animal was effectively treated with diazoxide.

  8. 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

  9. 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...

  10. 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...

  11. 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...

  12. Peptide immunization of guinea pigs against Chlamydia psittaci (GPIC agent) infection induces good vaginal secretion antibody response, in vitro neutralization and partial protection against live challenge.

    PubMed

    Volp, K; Mathews, S; Timms, P; Hafner, L

    2001-06-01

    Immunization of female guinea pigs with a chimeric peptide consisting of variable domain IV (VDIV) and a region known as GP8 from the major outer membrane protein of Chlamydophila caviae, formerly Chlamydia psittaci guinea pig inclusion conjunctivitis strain, was performed to assess whether humoral immune responses could be elicited in the reproductive tracts of immunized animals. The C. caviae strain is able to cause a sexually transmitted infection in the guinea pig that closely parallels C. trachomatis infections in humans. The best anti-VDIV antibody response in vaginal secretions was achieved by intraperitoneal priming with subsequent intravaginal boosting (P < 0.001). Dot-blot analyses of vaginal secretions confirmed that these anti-VDIV antibodies, produced against a linear peptide, were able to recognize and bind to whole conformational C. caviae elementary bodies. Following live intravaginal challenge with C. caviae, a significant reduction in the intensity (P = 0.01) and an apparent reduction in the duration of the infection was evident between the guinea pigs immunized with VDIV-GP8 and non-immunized controls.

  13. 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

  14. 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.

  15. 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.

  16. Transmission in the guinea pig model.

    PubMed

    Lowen, Anice C; Bouvier, Nicole M; Steel, John

    2014-01-01

    The ability of an influenza virus to transmit efficiently from human-to-human is a major factor in determining the epidemiological impact of that strain. The use of a relevant animal model to identify viral determinants of transmission, as well as host and environmental factors affecting transmission efficiency, is therefore critical for public health. The characterization of newly emerging influenza viruses in terms of their potential to transmit in a mammalian host is furthermore an important part of pandemic risk assessment. For these reasons, a guinea pig model of influenza virus transmission was developed in 2006. The guinea pig provides an important alternative to preexisting models for influenza. Most influenza viruses do not readily transmit among mice. Ferrets, while highly relevant, are expensive and can be difficult to obtain in high numbers. Moreover, it is generally accepted that efforts to accurately model human disease are strengthened by the use of multiple animal species. Herein, we provide an overview of influenza virus infectivity, growth, and transmission in the guinea pig and highlight knowledge gained on the topic of influenza virus transmission using the guinea pig model.

  17. Chlamydial pneumonitis induced in newborn guinea pigs.

    PubMed Central

    Rank, R G; Hough, A J; Jacobs, R F; Cohen, C; Barron, A L

    1985-01-01

    One- to three-day-old guinea pigs were inoculated intranasally with the chlamydial agent of guinea pig inclusion conjunctivitis. Physical signs of infection included a marked increase in respiration rate on days 5 to 10 of infection and radiographic evidence of pneumonia on day 6. When animals were killed at various times after infection and lung tissue was examined by histopathology, evidence of pneumonia was found beginning on day 4 and lasting as long as day 12, with maximal pathological changes on days 6 to 8. The pneumonia was generally unilateral and consisted of an acute inflammatory component in the bronchioles with granulocytes in both the lumen and the wall of the bronchioles and an interstitial and intra-alveolar mononuclear infiltrate in the parenchyma of the lung. Chlamydial antigen was detected in the bronchial epithelial cells by immunoperoxidase staining, and the guinea pig inclusion conjunctivitis organism was isolated from lung tissue on days 6 to 9. No other significant bacteria were isolated from lung tissue or seen on gram stains of lung sections. Both immunoglobulin M and immunoglobulin G serum antibodies to the guinea pig inclusion conjunctivitis agent were detected as early as day 8 and reached peak levels on day 12. The infection was apparently self-limiting. This model presents the opportunity to investigate pathophysiological and immunological aspects of chlamydial respiratory infections in a neonatal animal. Images PMID:3980080

  18. Instituting Dark-Colored Cover to Improve Central Space Use Within Guinea Pig Enclosure.

    PubMed

    Byrd, Charles P; Winnicker, Christina; Gaskill, Brianna N

    2016-01-01

    Domestic guinea pigs (Cavia aperea f. porcellus) in laboratories have been shown to actively avoid the centers of their cages. This experiment tested a novel, dark-colored "shader" placed over the central portion of a cage. Based on the observed behavior of wild guinea pig species, it was hypothesized that utilization of the central portion of the cage would increase when the shader was present. Eleven male and 11 female albino, 3-week-old Hartley guinea pigs (Crl:HA) experienced the control and treatment conditions in a crossover study design. They spent more time in central cage sections when the shader was present and spent more time in and around the food hopper when the shader was absent (p < .001). Differences between sexes included increased inactivity in males versus females (p < .05) and a difference in time spent in a corner section of the cage (p < .001), likely associated with location in the room. We concluded that the presence of a shader increased utilization of cage space, which appeared to provide a similar increase in space utilization as structural enrichments.

  19. The cochleogram of the guinea pig.

    PubMed

    Linss, Volker; Linss, Werner; Emmerich, Edeltraut; Richter, Frank

    2007-04-01

    The cochleogram is an important tool to relate properties of the cochlea (e.g. hair cell loss, damaged hair cells) to their position in the cochlear turns, to calculate the average hair cell density, and to measure the length of the whole cochlea. In this work different methods of plotting cochleograms are compared. We suggest that a sector-wise division of the cochlea for counting a cochleogram has advantages over line diagrams that provide a higher spatial resolution but might lead to misinterpretations of the degree of missing hair cells. The scanning electron microscopic analysis of 171 guinea pig cochleas revealed a mean basilar membrane length of 16.4 +/- 1.4 mm (mean +/- standard deviation) with sector lengths of 6.9, 4.2, 3.2, and 1.9 mm, thus adding relevant information to the morphology of the guinea pig cochlea. PMID:17082943

  20. 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

  1. Methoxatin (PQQ) in guinea-pig neutrophils.

    PubMed

    Bishop, A; Paz, M A; Gallop, P M; Karnovsky, M L

    1994-10-01

    PQQ, also called methoxatin, has been isolated from guinea-pig neutrophils. The organic cations diphenyleneiodonium (DPI) and diphenyliodonium (BPI) and the aromatic o-diamine 4,5-dimethylphenylenediamine (DIMPDA) sequester synthetic PQQ and inhibit its redox-cycling activity in a model system. Standards were made of adducts of tritiated PQQ with unlabeled DIMPDA and of unlabeled PQQ with tritiated DPI or DIMPDA. PQQ adducts were isolated from guinea-pig neutrophils with each of the tritiated inhibitors. They were separated and defined by high-performance liquid chromatography (HPLC). Tiron, a disodium benzene disulphonic acid, broke the DPI-PQQ adduct isolated from neutrophils and released free PQQ. Both DPI and DIMPDA, as well as BPI, blocked O2.- release by stimulated neutrophils. The blockade exerted by these inhibitors was released by the addition of PQQ to the cell suspensions. The data demonstrate the presence of PQQ in guinea-pig neutrophils and suggest that it has a possible role, direct or indirect, in the O2.(-)-producing respiratory burst.

  2. Development of the first oligonucleotide microarray for global gene expression profiling in guinea pigs: defining the transcription signature of infectious diseases

    PubMed Central

    2012-01-01

    Background The Guinea pig (Cavia porcellus) is one of the most extensively used animal models to study infectious diseases. However, despite its tremendous contribution towards understanding the establishment, progression and control of a number of diseases in general and tuberculosis in particular, the lack of fully annotated guinea pig genome sequence as well as appropriate molecular reagents has severely hampered detailed genetic and immunological analysis in this animal model. Results By employing the cross-species hybridization technique, we have developed an oligonucleotide microarray with 44,000 features assembled from different mammalian species, which to the best of our knowledge is the first attempt to employ microarray to study the global gene expression profile in guinea pigs. To validate and demonstrate the merit of this microarray, we have studied, as an example, the expression profile of guinea pig lungs during the advanced phase of M. tuberculosis infection. A significant upregulation of 1344 genes and a marked down regulation of 1856 genes in the lungs identified a disease signature of pulmonary tuberculosis infection. Conclusion We report the development of first comprehensive microarray for studying the global gene expression profile in guinea pigs and validation of its usefulness with tuberculosis as a case study. An important gap in the area of infectious diseases has been addressed and a valuable molecular tool is provided to optimally harness the potential of guinea pig model to develop better vaccines and therapies against human diseases. PMID:23031549

  3. 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…

  4. 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. PMID:26432777

  5. 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.

  6. A 2-D guinea pig lung proteome map

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. ANAPHYLAXIS IN CHOPPED GUINEA PIG LUNG

    PubMed Central

    Austen, K. F.; Brocklehurst, W. E.

    1961-01-01

    The quantitative release of histamine by specific antigen from perfused, chopped, sensitized guinea pig lung has been used to study the effect of peptidase substrates and inhibitors on the anaphylactic reaction. The anaphylactic release of histamine is prevented by chymotrypsin substrates and inhibitors but not by trypsin, carboxypeptidase, or leucine aminopeptidase substrates or the soybean trypsin inhibitor. The chymotrypsin substrates and inhibitors appear to be acting on an antigen-antibody-activated step because these substances fail to inhibit if the tissue is washed free of them prior to antigen addition, and because there is complete desensitization of the tissue without histamine release when the antigen is added in the presence of these inhibitors. The inhibitors work equally well in tissue from passively sensitized animals or in tissue from animals actively sensitized with either ovalbumin or bovine gamma globulin. These observations suggest that activation of a chymotrypsin-like enzyme is a necessary condition for the anaphylactic release of histamine in guinea pig lung. Diisopropylfluophosphate is inhibitory when present at the time of antigen addition but not when the tissue is washed free of unfixed diisopropylfluophosphate prior to adding antigen. This indicates that diisopropylfluophosphate must be acting exclusively on an enzyme which exists in lung tissue in a precursor form resistant to diisopropylfluophosphate until activated by the antigen-antibody interaction. Thiol alkylating or oxidizing agents also prevent the anaphylactic release of histamine, but in contrast to the situation with diisopropylfluophosphate and the other chymotrypsin inhibitors, the phase of the anaphylactic reaction inhibited by N-ethylmaleimide is available prior to the antigen-antibody interaction. The similarities and differences between immune hemolysis and anaphylaxis in chopped guinea pig lung are considered in detail. PMID:13685194

  8. Biosynthesis of plasmenylcholine in guinea pig heart

    SciTech Connect

    Wientzek, M.; Choy, P.C.

    1986-05-01

    In some mammalian hearts, up to 40% of the choline phosphoglyceride (CPG) exists as plasmenylcholine (1-alkenyl-2-acyl-glycero-3-phosphocholine). Although the majority of diacylphosphatidylcholine (PC) in mammalian hearts is synthesized from choline via the CDP-choline pathway, the formation of plasmenylcholine from choline was not known. In this study, they investigated the biosynthesis of plasmenyl-choline in the isolated guinea pig heart by perfusion with (/sup 3/H)choline. Labelled choline containing metabolites and labelled plasmenylcholine were isolated and determined at different perfusion time points. Significant amounts of labelling were found only in choline, phosphocholine, CDP-choline, plasmenyl-choline and PC. In addition, a precursor-product relationship was observed between the labelling of CDP-choline and plasmenylcholine. Such a relationship was not observed between choline and plasmenylcholine. Hence, they postulate that the incorporation of choline into plasmenylcholine is via the CDP-choline pathway and not via base exchange. The ability to condense 1-alkenyl-2-acyl-glycerol with CDP-choline was also demonstrated in vitro with guinea pig heart microsomes.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... observed for 7 days. (b) If unfavorable reactions attributable to the product occur in either of the guinea pigs during the observation period, the serial or subserial is unsatisfactory. If unfavorable...

  15. Absence of pork-like insulin in guinea pig tissues.

    PubMed Central

    Eng, J; Yalow, R S

    1982-01-01

    By using a technique for concentrating insulin 100-fold from tissue extracts with 75-95% recoveries, we earlier failed to detect pork-like insulin in guinea pig tissues and thus were unable to confirm reports from the National Institutes of Health that these tissues contain a pork-like insulin at concentrations averaging 1 ng/g. This difference could have been due to differences in strains of guinea pigs studied or in the species specificities of the antisera used for radioimmunoassay. In the current study, tissue extracts from both NIH and Hartley guinea pigs were assayed with three antisera routinely used in our laboratory and one antiserum that had been used in the National Institutes of Health laboratory. We observed that pork-like insulin in tissues from both strains of guinea pigs as determined with the four antisera is less than 0.02 ng/g. We therefore conclude that is is unlikely that nonpancreatic guinea pig tissues contain or synthesize a peptide resembling pork or other non-guinea pig mammalian insulin. PMID:7045868

  16. Astragalosides reduce cisplatin ototoxicity in guinea pigs.

    PubMed

    Xiong, Min; He, Qinglian; Wang, Jian; Lai, Huangwen

    2011-01-01

    Cisplatin is known to cause high-frequency neurosensory hearing loss. While reactive oxygen species have been shown to play a role, reactive nitrogen species have been implicated, but not proven to be involved, in cisplatin ototoxicity. The purpose of the present study was to investigate the role of nitric oxide (NO) in cisplatin ototoxicity by administering astragalosides, a natural antioxidant, in conjunction with cisplatin. Guinea pigs were injected with cisplatin, astragalosides or both. Auditory brainstem-evoked responses (ABRs) were measured before and 3 days after cisplatin administration. The cochlear tissue was then assayed for NO and malondialdehyde (MDA), and cochleae were also examined by scanning electron microscopy. Cisplatin alone caused significant ABR threshold shifts at all stimuli tested, whereas astragalosides alone caused no shifts. There was a significant reduction in threshold shift for clicks, 8-kHz and 16-kHz tone bursts (but not 32 kHz) when astragalosides was given with cisplatin. Both the MDA concentration and the NO concentration in the astragalosides/cisplatin group were significantly lower than those of the cisplatin group. Correspondingly, the loss of outer hair cells in the astragalosides/cisplatin group was much less than that in the cisplatin group. This suggests that astragalosides reduces cisplatin ototoxicity by its antioxidant property. PMID:21494054

  17. 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.

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

    PubMed

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

    2014-01-01

    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. PMID:25350490

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

    PubMed

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

    2014-01-01

    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.

  20. Non-Terminal Blood Sampling Techniques in Guinea Pigs

    PubMed Central

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

    2014-01-01

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models1-3. 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 disadvantages4,5. 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 animals6. All the described methods have been thoroughly tested and applied for repeated in vivo blood sampling in studies within our research facility. PMID:25350490

  1. 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

  2. Severe gastritis in guinea-pigs infected with Helicobacter pylori.

    PubMed

    Sturegård, E; Sjunnesson, H; Ho, B; Willén, R; Aleljung, P; Ng, H C; Wadström, T

    1998-12-01

    An appropriate animal model is essential to study Helicobacter pylori infection. The aim of this study was to investigate if H. pylori can colonise the guinea-pig stomach and whether the infection causes gastritis and a serological response similar to that observed in man. Guinea-pigs were infected either with fresh H. pylori isolates from human gastric biopsies or with a guinea-pig passaged strain. When the animals were killed, 3 and 7 weeks after inoculation, samples were taken for culture, histopathology and serology. H. pylori was cultured from 22 of 29 challenged animals. All culture-positive animals exhibited a specific immune response against H. pylori antigens in Western blotting and gastritis in histopathological examination. Antibody titres in enzyme immunoassay were elevated among animals challenged with H. pylori. The inflammatory response was graded as severe in most animals and consisted of both polymorphonuclear leucocytes and lymphocytes. Erosion of the gastric epithelium was found in infected animals. These results suggest that the guinea-pig is suitable for studying H. pylori-associated diseases. Moreover, guinea-pigs are probably more similar to man than any other small laboratory animal as regards gastric anatomy and physiology.

  3. 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...

  4. 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...

  5. 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...

  6. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways.

    PubMed

    Zaccone, Eric J; Lieu, TinaMarie; Muroi, Yukiko; Potenzieri, Carl; Undem, Blair E; Gao, Peisong; Han, Liang; Canning, Brendan J; Undem, Bradley J

    2016-01-01

    The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ "cough receptors" such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli. PMID:27213574

  7. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways

    PubMed Central

    Lieu, TinaMarie; Muroi, Yukiko; Potenzieri, Carl; Undem, Blair E.; Gao, Peisong; Han, Liang; Canning, Brendan J.

    2016-01-01

    The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ “cough receptors” such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli. PMID:27213574

  8. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways.

    PubMed

    Zaccone, Eric J; Lieu, TinaMarie; Muroi, Yukiko; Potenzieri, Carl; Undem, Blair E; Gao, Peisong; Han, Liang; Canning, Brendan J; Undem, Bradley J

    2016-01-01

    The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ "cough receptors" such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli.

  9. 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

  10. 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.

  11. Measurement of cochlear acoustic pressure in guinea pigs

    NASA Astrophysics Data System (ADS)

    Franke, R.; Dancer, A.

    1983-10-01

    Guinea pig cochlear acoustic pressure was measured in the 3 to 200 Hz range. The cochlear microphonic potential was recorded. The experimental results agree with the Peterson and Bogert model. The pressure transducers and the calibrating device are confirmed to be excellent tools for this type of research.

  12. 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.

  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. 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.

  15. Gallbladder motility and the sex of the guinea pig.

    PubMed

    Kline, Loren; Karpinski, Edward

    2016-06-01

    Progesterone (P), 17β-estradiol (E2), and dihydrotestosterone (DHT) affect gallbladder motility. When gallbladders were taken from women and men, women had more estrogen and P receptors than men. Both P and E2 had an inhibitory effect upon gallbladder contractility in men and premenopausal and postmenopausal women. Similar findings have been reported in gallbladder strips from male and female guinea pigs. In the present study, there was no significant difference in the amount of E2-, P-, or DHT-induced relaxation of CCK-induced tension when the responses in gallbladder strips from male and female guinea pigs were compared. Three metabolites of P were used: 17-hydroxyprogesterone (17-P), 20α-hydroxyprogesterone (20-P), and 21-hydroxyprogesterone (21-P). There was no significant difference in the responses from strips from male and female guinea pigs. In order to determine if the effects of E2 and P were additive, strips from male animals were exposed to either E2 or P and the amount of relaxation recorded. After recovery, the strips were exposed to E2 or P in reverse order to ensure the order of treatment had no effect. Then, the strips were treated with both E2 and P simultaneously and the relaxation recorded. This procedure was repeated with strips from female guinea pigs. The effect of E2 and P was found to be additive; however, the response of the strips from each sex were not significantly different. It is concluded that the sex of the guinea pig has no significant effect on the response to the sex hormones used. PMID:27354545

  16. Gallbladder motility and the sex of the guinea pig.

    PubMed

    Kline, Loren; Karpinski, Edward

    2016-06-01

    Progesterone (P), 17β-estradiol (E2), and dihydrotestosterone (DHT) affect gallbladder motility. When gallbladders were taken from women and men, women had more estrogen and P receptors than men. Both P and E2 had an inhibitory effect upon gallbladder contractility in men and premenopausal and postmenopausal women. Similar findings have been reported in gallbladder strips from male and female guinea pigs. In the present study, there was no significant difference in the amount of E2-, P-, or DHT-induced relaxation of CCK-induced tension when the responses in gallbladder strips from male and female guinea pigs were compared. Three metabolites of P were used: 17-hydroxyprogesterone (17-P), 20α-hydroxyprogesterone (20-P), and 21-hydroxyprogesterone (21-P). There was no significant difference in the responses from strips from male and female guinea pigs. In order to determine if the effects of E2 and P were additive, strips from male animals were exposed to either E2 or P and the amount of relaxation recorded. After recovery, the strips were exposed to E2 or P in reverse order to ensure the order of treatment had no effect. Then, the strips were treated with both E2 and P simultaneously and the relaxation recorded. This procedure was repeated with strips from female guinea pigs. The effect of E2 and P was found to be additive; however, the response of the strips from each sex were not significantly different. It is concluded that the sex of the guinea pig has no significant effect on the response to the sex hormones used.

  17. 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.

  18. 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.

  19. Homologous radioimmunoassay for guinea pig corticosteroid-binding globulin

    SciTech Connect

    Hsu, B.R.S.; Kato, E.A.; Raymoure, W.J.; Kuhn, R.W.

    1987-07-01

    A rapid, specific, and sensitive (requiring only 20 fmole of antigen equivalent to 0.007) l of serum) radioimmunoassay (RIA) was developed for the measurement of guinea pig corticosteroid-binding globulin (CBG). CBG was purified to homogeneity from guinea pig serum by affinity chromatography and used for immunization, as the standard and as the radiolabeled trace in the RIA. The antiserum to CBG was raised in rabbits. It was judged specific by immunoelectrophoresis and by comparison of RIA values with steroid-binding assay profiles obtained on serum separated on the basis of size and ion-exchange properties. The results of the radioimmunoassays agree with those of a steroid-binding assay run on identical samples. The sensitivity of the assay allows detection of CBG in serial serum samples, other biologic fluids such as milk, and cell culture supernatants.

  20. 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.

  1. Immunoreactive atrial natriuretic peptide in the guinea pig spleen

    SciTech Connect

    Vollmar, A.M.; Friedrich, A.; Schulz, R. )

    1989-01-01

    The presence of immunoreative ANP precursor-like material in the guinea pig spleen is suggested. This is based on the following experimental evidence: An acidic extract of guinea pig spleen analyzed by Sephadex G-50 gel filtration contained 4.6 pmol/g wet tissue immunoreactive atrial natriuretic peptide (IR-ANP), IR-ANP coeluting with 15 kDa synthetic ANP (2-126). Gel filtrated IR-ANP material was further submitted to reverse phase high performance liquid chromatography and monitored by radioimmunoassay employing two antisera. One antiserum recognizes the C-terminal of ANP (1-126), the second is directed against the N-terminal sequence. Both antisera revealed material eluting with synthetic ANP (2-126). Furthermore, immunohistochemical analysis suggests this ANP-like material to be localized mainly at the periphery of the white pulp of the spleen. These findings link ANP with the immune system.

  2. Autonomic Nerve Regulation of Colonic Peristalsis in Guinea Pigs

    PubMed Central

    Gribovskaja-Rupp, Irena; Babygirija, Reji; Takahashi, Toku; Ludwig, Kirk

    2014-01-01

    Background/Aims Colonic peristalsis is mainly regulated via intrinsic neurons in guinea pigs. However, autonomic regulation of colonic motility is poorly understood. We explored a guinea pig model for the study of extrinsic nerve effects on the distal colon. Methods Guinea pigs were sacrificed, their distal colons isolated, preserving pelvic nerves (PN) and inferior mesenteric ganglia (IMG), and placed in a tissue bath. Fecal pellet propagation was conducted during PN and IMG stimulation at 10 Hz, 0.5 ms and 5 V. Distal colon was connected to a closed circuit system, and colonic motor responses were measured during PN and IMG stimulation. Results PN stimulation increased pellet velocity to 24.6 ± 0.7 mm/sec (n = 20), while IMG stimulation decreased it to 2.0 ± 0.2 mm/sec (n = 12), compared to controls (13.0 ± 0.7 mm/sec, P < 0.01). In closed circuit experiments, PN stimulation increased the intraluminal pressure, which was abolished by atropine (10−6 M) and hexamethonium (10−4 M). PN stimulation reduced the incidence of non-coordinated contractions induced by NG-nitro-L-arginine methyl ester (L-NAME; 10−4 M). IMG stimulation attenuated intraluminal pressure increase, which was partially reversed by alpha-2 adrenoceptor antagonist (yohimbine; 10−6 M). Conclusions PN and IMG input determine speed of pellet progression and peristaltic reflex of the guinea pig distal colon. The stimulatory effects of PN involve nicotinic, muscarinic and nitrergic pathways. The inhibitory effects of IMG stimulation involve alpha-2 adrenoceptors. PMID:24847719

  3. 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.

  4. Strain differences in guinea pigs' bronchial sensitivity to acetylcholine.

    PubMed

    Mikami, H; Nishibata, R; Kawamoto, Y; Ino, T

    1990-01-01

    The bronchial sensitivity to acetylcholine (ACh) of guinea pigs of various strains was investigated to clarify strain differences. Inbred Strain 2, Strain 13 and JY-1 and non-inbred Hartley strain (two colonies) were used in this experiment. (1) Guinea pigs were exposed to 0.08% ACh aerosol and the time needed to produce falling down (TNPFD) was determined. Mean +/- standard error of TNPFD (n = 14 per group) of animals was 182 +/- 28 sec, 148 +/- 22 sec, 210 +/- 30 sec, 342 +/- 24 sec and 406 +/- 36 sec in Strain 2, Strain 13, JY-1, Hartley (Japan SLC) and Hartley (Hitachi), respectively. There was a significant difference in TNPFD between inbred strains and non-inbred strains (P less than 0.05 or P less than 0.01), indicating that inbred strains had higher sensitivity. (2) Guinea pigs were exposed to 20-5000 micrograms/ml ACh for 2 min. The mean dose threshold as determined by transcutaneous oxygen pressure was 524 micrograms/ml, 424 micrograms/ml, 614 micrograms/ml, 1317 micrograms/ml and 1651 micrograms/ml (n = 14 per group) in Strain 2, Strain 13, JY-1, Hartley (Japan SLC) and Hartley (Hitachi), respectively. Inbred strains showed lower dose thresholds than non-inbred strains. (3) Isolated trachea-lungs of 5 guinea pigs were perfused with 10(-9)-10(-5) g/ml ACh to determine strain differences. Dose response curves of animals of inbred strains shifted to the left (lower concentrations), unlike those of non-inbred strains, suggesting that inbred strains had higher sensitivity to ACh than non-inbred strains.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. 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.

  6. Tracheal ultrastructure in kerosene treated guinea pigs. A preliminary report.

    PubMed

    Noa, N; Sanabria, J

    1984-01-01

    p6high correlation between the usage of kerosene and the appearance of asthmatic crises has been demonstrated. The ultrastructure of the upper respiratory tract of animals treated with kerosene has not been previously reported. Kerosene aerosol was administered for 15 minutes daily during 21 days to adult male guinea pigs with fragments of trachea being processed for ultrathin electron microscopical studies. Controls did not receive any treatment. Trachea of guinea pigs submitted to kerosene aerosols showed swelling, ruffling and breakdown of the ciliary membrane. The regularly arranged ciliary border was disturbed to a certain degree in some areas by the development of cytoplasmatic protrusions at the apical part of the ciliated cells. An eosinophilic infiltrate was observed deep inside the epithelium and into the lamina propria. Therefore, these ciliary alterations can be considered as one of the most important changes induced by kerosene in tracheal epithelial cells. The protrusions may represent a sign of cell alteration produced by kerosene aerosol inhalation in the guinea pig.

  7. 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.

  8. Infection of Guinea Pigs with Vesicular Stomatitis New Jersey Virus Transmitted by Culicoides sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interpretive Biting midges,Culicoides sonorensis were shown to be capable of transmitting vesicular stomatitis New Jersey virus (VSNJV) to guinea pigs. Despite seroconversion for VSNJV, none of the guinea pigs developed clinical signs when infected in the abdomen by either infected insects or by nee...

  9. 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.

  10. The maternal social environment shapes offspring growth, physiology, and behavioural phenotype in guinea pigs

    PubMed Central

    2015-01-01

    Background Prenatal conditions influence offspring development in many species. In mammals, the effects of social density have traditionally been considered a detrimental form of maternal stress. Now their potential adaptive significance is receiving greater attention.Sex-specific effects of maternal social instability on offspring in guinea pigs (Cavia aperea f. porcellus) have been interpreted as adaptations to high social densities, while the effects of low social density are unknown. Hence, we compared morphological, behavioural and physiological development between offspring born to mothers housed either individually or in groups during the second half of pregnancy. Results Females housed individually and females housed in groups gave birth to litters of similar size and sex-ratios, and there were no differences in birth weight. Sons of individually-housed mothers grew faster than their sisters, whereas daughters ofgroup-housed females grew faster than their brothers, primarily due to an effect on growth of daughters. There were few effects on offspring behaviour. Baseline cortisol levels in saliva of pups on day 1 and day 7 were not affected, but we saw a blunted cortisol response to social separation on day 7 in sons of individually-housed females and daughters of group-housed females. The effects were consistent across two replicate experiments. Conclusions The observed effects only partially support the adaptive hypothesis. Increased growth of daughters may be adaptive under high densities due to increasedfemale competition, but it is unclear why growth of sons is not increased under low social densities when males face less competition from older, dominant males. The differences in growth may be causally linked to sex-specific effects on cortisol response, although individual cortisol response and growth were not correlated, and various other mechanisms are possible. The observed sex-specific effects on early development are intriguing, yet the potential

  11. Comparative study of Helicobacter pylori infection in guinea pigs and mice - elevation of acute-phase protein C3 in infected guinea pigs.

    PubMed

    Sjunnesson, H; Sturegård, E; Grubb, A; Willén, R; Wadström, T

    2001-03-01

    Eighteen Dunkin-Hartley guinea pigs and 50 NMRI mice were inoculated with Helicobacter pylori and the infection followed by culture, histopathology, antibody response, and plasma levels of the acute-phase proteins albumin, C3, and transferrin for up to 7 weeks. The immune response to H. pylori surface proteins was studied by an enzyme immunoassay (EIA) and Western immunoblot and the plasma levels of albumin, C3, and transferrin were analyzed by single radial immunodiffusion. Guinea pigs had a more severe gastritis and a higher EIA immune response than NMRI mice. Serum C3 levels were elevated in infected guinea pigs after 3 and 7 weeks indicating a systemic inflammatory response and a possible link between H. pylori infection and extragastric manifestations such as vasculitis associated with atherosclerosis. Serum cholesterol levels were analyzed in guinea pigs at 7 weeks and indicated a higher level in H. pylori-infected than in control animals, but this difference was not statistically significant.

  12. 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.

  13. 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

  14. Chlamydial infection of subcutaneous conjunctival transplants in guinea pigs.

    PubMed

    Pham, R T; Sung, M; Dawson, C R; Schachter, J

    1990-07-01

    The development and testing of candidate vaccines for trachoma are constrained because only humans and nonhuman primates are susceptible to conjunctival infection with Chlamydia trachomatis. Guinea pig inclusion conjunctivitis (GPIC), an analogous disease of guinea pigs, provides a useful, less expensive model to study ocular chlamydial infections. GPIC is caused by a Chlamydia psittaci strain whose external constituents are very similar to those of C. trachomatis. To develop a better model for studying GPIC immunity, conjunctival pockets were established under the abdominal skin of guinea pigs by subcutaneous implantation. Up to six implants could be produced in each animal. The success rate of implantation was 79.0% (n = 148). These pockets were then infected with GPIC. The organism was recovered from the autografts indicating local replication, and tests for serum antibody by microimmunofluorescence showed production of GPIC-specific antibody of IgG and IgM classes after infection. There was minimal antibody response after moderate inoculating doses to the implants, and the titers increased more slowly than after eye infection with GPIC; with higher concentration of the inoculum, however, the antibody response increased to the same levels as with the ocular challenge but more slowly. Inoculation of pockets with GPIC also produced acute inflammatory changes in infected autografts (n = 101). Histologic examination of infected grafts showed chlamydial inclusions in epithelial cells and significant infiltration with lymphocytes and polymorphonuclear cells. Subcutaneous autografts may provide a useful model for chronologic studies of chlamydial infection. The delayed immunologic response, however, suggests that these pockets of implanted epithelium do not have full access to the immune system.

  15. Growth failure after recurrent fever in young guinea pigs.

    PubMed

    Madu, S C; Faurie, A; Pettifor, J M; Laburn, H P

    2007-03-16

    Infection causes fever and suppression of appetite, a combination of effects which threatens normal growth in infected children. We have used an animal model to study the effects on growth of recurrent simulated Gram-positive bacterial infection. After weaning, 10 guinea pig pups underwent surgery under general anaesthesia for the implantation of temperature-sensitive radiotelemeters and thereafter were assigned to receive intramuscular injections of either 50 microg/kg muramyl dipeptide (MDP), or sterile saline. During a 30-day period corresponding to their rapid growth phase, the pups were given eight injections. MDP resulted in fevers of about 1.5 degrees C on each occasion, but no significant change in body temperature occurred after saline injections. Food intake was suppressed during each febrile episode such that 24-h intake was significantly lower on days of injections of MDP, compared to days between MDP injections in the same animals, and compared to that of animals injected with saline. The rate of weight gain of the MDP-injected guinea pigs was significantly lower than that of the control group and failed even to achieve a rate similar to the saline-injected group in their more adult-like growth phase. Plasma zinc concentration was significantly lower in MDP-compared to saline-injected animals sampled 8 days after the last injection. Our results show that recurrent fever during the growth phase of young guinea pigs results in irreversible growth failure, and that reduced food intake on days when the animals were febrile was at least partly responsible for this reduced rate of growth.

  16. 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. PMID:26837703

  17. Allergy to guinea pigs: II Identification of specific allergens in guinea pig dust by crossed radio-immunoelectrophoresis and investigation of the possible origin.

    PubMed

    Walls, A F; Newman Taylor, A J; Longbottom, J L

    1985-11-01

    An extract of dust from the air-vent filters of a room housing guinea pigs was analysed by quantitative immunoelectrophoretic procedures and compared with extracts of various materials derived from guinea pigs. Crossed radio-immunoelectrophoresis (CRIE) of the dust, performed with sera from twenty asthmatic patients who were positive by skin testing and RAST to guinea pig extracts, identified fourteen IgE-binding constituents. Although responses varied, most sera reacted with four particular allergens, antigens 2, 3, 10 and Sl. The numbers of allergens recognized by individual patients correlated with the RAST score, but not with total serum IgE. All seventeen dust constituents detected by crossed immunoelectrophoresis (and all four major allergens), were also present in extracts of guinea pig dander, fur, saliva and urine; several of these components were absent in an epithelial extract, and there were even less in preparations of shaved pelt, serum or faeces. None of the dust extract antigens were detected in materials used in animal husbandry, dust samples from rooms without guinea pigs, or a D. pteronyssinus extract. These findings suggest that inhalant allergens may be derived predominantly from material shed from the guinea pig coat after contamination with saliva, and possibly to a lesser extent, urine. PMID:2416489

  18. 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. PMID:26948264

  19. Anatomy and Disorders of the Oral Cavity of Guinea Pigs.

    PubMed

    Legendre, Loic

    2016-09-01

    Acquired dental disease represents the most common oral disorder of guinea pigs. Most patients are presented with nonspecific clinical signs and symptoms, such as weight loss, reduced food intake, difficulty chewing and/or swallowing. The physical examination must be followed by standard radiography and/or computed tomography, and thorough inspection under general anesthesia. Several complications may follow, including periodontal disease, subluxation of the temporomandibular joint, periapical infection, and abscessation. The dental treatment is aimed to restore the proper length and shape of both the incisor and cheek teeth, associated with medical and supportive treatment. Abscesses should be surgically addressed by complete excision. PMID:27497208

  20. 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. PMID:27066228

  1. 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.

  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. 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.

  4. THE FINE STRUCTURE OF TESTICULAR INTERSTITIAL CELLS IN GUINEA PIGS

    PubMed Central

    Christensen, A. Kent

    1965-01-01

    In guinea pig testes perfused with either glutaraldehyde or osmium tetroxide fixative, the cytoplasm of the interstitial cells contains an exceptionally abundant agranular endoplasmic reticulum. The reticulum in central regions of the cell is a network of interconnected tubules, but in extensive peripheral areas the reticulum is commonly organized into closely packed, flattened cisternae which are fenestrated. Occasional small patches of the granular reticulum occur in the cytoplasm and connect freely with the agranular reticulum. The mitochondria have a dense matrix and contain cristae and some tubules. The Golgi complex is disperse and shows no evidence of secretory material. The cytoplasm also contains lipid droplets. Lipofuscin pigment granules are probably polymorphic residual bodies and contain three components: (1) a dense material which at high magnification shows a 75-A periodicity; (2) a medium-sized lipid droplet; and (3) a cap-like structure. In glutaraldehyde-perfused testis the interstitial cell cytoplasm appears to have the same density from cell to cell, and the agranular reticulum is tubular or cisternal but not in the form of empty vesicles. Thus the "dark" and "light" cells and the vesicular agranular reticulum sometimes encountered in other fixations may be artifacts. Biochemical results from other laboratories, correlated with the present findings, indicate that the membranes of the agranular endoplasmic reticulum in guinea pig interstitial cells are the site of at least two enzymes of androgen biosynthesis, the 17-hydroxylase and the 17-desmolase. PMID:19866687

  5. 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.

  6. Low barometric pressure aggravates neuropathic pain in guinea pigs.

    PubMed

    Sato, Jun; Itano, Yuya; Funakubo, Megumi; Mizoguchi, Hiroyuki; Itoh, Mariko; Mori, Rarami

    2011-10-01

    Several clinical studies have demonstrated a consistent relationship between changes in meteorological factors, particularly barometric pressure, and pain intensity in subjects with chronic pain. We have previously demonstrated that exposure to artificially low barometric pressure (LP) intensifies pain-related behaviors in rats with neuropathic pain. In the present study, guinea pigs with unilateral L5 spinal nerve ligation (SNL) were placed in a pressure-controlled chamber and subjected to LP of 10 or 27hPa below the ambient pressure. The SNL surgery led to increased hindpaw withdrawal frequencies to 34-, 59-, and 239-mN von Frey filaments (VFFs). When the SNL animals were subjected to both LP exposures consecutively, the hindpaw withdrawal frequencies further increased; the effect was most significant when the animals were exposed to LP 27hPa below ambient pressure. In contrast, no change was seen in a group of sham-operated control animals. These results indicate that fluctuations in LP within the range of natural weather patterns can potentiate neuropathic pain in guinea pigs.

  7. Chlamydial salpingitis in female guinea pigs receiving oral contraceptives.

    PubMed

    Barron, A L; Pasley, J N; Rank, R G; White, H J; Mrak, R E

    1988-01-01

    Female guinea pigs were given daily doses of a combination of oral contraceptive (OC) agents, consisting of mestranol and norethynodrel suspended in sesame oil or distilled H2O, and were infected in the genital tract with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). Counts of chlamydial inclusions in cells of vaginal smears collected during infection, showed prolongation and enhancement of infection in OC-treated animals as compared with controls. Appearance of IgG and IgA antibodies to GPIC in genital secretions, as determined by enzyme-linked immunosorbent assay (ELISA), was also delayed in OC-treated animals as compared with controls. OC-treated infected animals were killed on days 15 and 43, and gross pathological evidence for ascending infection culminating in salpingitis was found in all of five and four of five animals, respectively. On the other hand, among untreated infected controls on each sacrifice day, only one of five animals had any evidence for ascending infection. Chlamydiae were detected by light and electron microscopy in fallopian tube tissue collected on day 15 following OC-treatment but not in tissue from control animals.

  8. 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.

  9. Five month persistence of Helicobacter pylori infection in guinea pigs.

    PubMed

    Sjunnesson, Hakan; Sturegard, Erik; Hynes, Sean; Willen, Roger; Feinstein, Ricardo; Wadstrom, Torkel

    2003-06-01

    Seven Dunkin-Hartley guinea pigs were infected with the Sydney strain of H. pylori (SS1). Gastric histopathology was evaluated and serum antibody response to H. pylori cell-surface proteins was analysed by enzyme immunoassay (EIA) and immunoblot. Tissue and faecal samples from five control animals were analysed for the presence of naturally occurring Helicobacter spp. infection by culture and Helicobacter genus-specific PCR. The H. pylori infection persisted for 5 months, in most animals accompanied by a histologically severe antral gastritis, exhibiting focal degeneration and necrosis of gastric crypt epithelium. Increased numbers of mitotic figures were observed in the gastric epithelium, indicating a regenerative process. Infected animals displayed specific antibodies towards H. pylori cell-surface proteins in immunoblot, whereas EIA was of dubious value creating false-positive results. Serum complement C3 and cholesterol levels appeared to be elevated in infected animals. Helicobacter spp. infection was not detected in the control animals. The persistent infection, accompanied by severe gastritis and a prominent serum antibody response, and the apparent absence of a natural Helicobacter spp. infection makes the guinea pig model useful in H. pylori research.

  10. Cortical evoked potentials recorded from the guinea pig without averaging.

    PubMed

    Walloch, R A

    1975-01-01

    Potentials evoked by tonal pulses and recorded with a monopolar electrode on the pial surface over the auditory cortex of the guinea pig are presented. These potentials are compared with average potentials recorded in previous studies with an electrode on the dura. The potentials recorded by these two techniques have similar waveforms, peak latencies and thresholds. They appear to be generated within the same region of the cerebral cortex. As can be expected, the amplitude of the evoked potentials recorded from the pial surface is larger than that recorded from the dura. Consequently, averaging is not needed to extract the evoked potential once the dura is removed. The thresholds for the evoked cortical potential are similar to behavioral thresholds for the guinea pig at high frequencies; however, evoked potential thresholds are eleveate over behavioral thresholds at low frequencies. The removal of the dura and the direct recording of the evoked potential appears most appropriate for acute experiments. The recording of an evoked potential with dura electrodes empploying averaging procedures appears most appropriate for chronic studies.

  11. Two Types of Calcium Channels in Guinea Pig Ventricular Myocytes

    NASA Astrophysics Data System (ADS)

    Mitra, Raman; Morad, Martin

    1986-07-01

    In cardiac muscle, Ca2+ plays a key role in regulation of numerous processes, including generation of the action potential and development of tension. The entry of Ca2+ into the cell is regulated primarily by voltage-gated channels in the membrane. Until recently, it was felt that only one type of Ca2+ channel existed in cardiac ventricular muscle. Experiments reported here suggest that in isolated guinea pig ventricular myocytes, there are two distinct types of Ca2+ channels with markedly different activation thresholds, inactivation kinetics, and sensitivities to inorganic and organic Ca2+ channel blockers. The channels were also distinguished based on their response to increased frequency of clamping such that the current through the low-threshold channel decreased while that through the high-threshold channel increased. In a few cells, the current through both channels was enhanced by isoproterenol, a β -adrenergic agonist, but only the high-threshold channel was enhanced by the Ca2+-channel agonist Bay K 8644. Thus, isolated guinea pig ventricular myocytes appear to have two types of Ca2+ channels distinguished by various criteria.

  12. Bambuterol: uptake and metabolism in guinea pig isolated lungs

    SciTech Connect

    Ryrfeldt, A.; Nilsson, E.; Tunek, A.; Svensson, L.A.

    1988-03-01

    The lung uptake and biotransformation of /sup 3/H-bambuterol, a prodrug to terbutaline, were studied using isolated perfused and ventilated guinea pig lungs. /sup 14/C-Sucrose was used as an extracellular marker. The lung uptake of bambuterol was significantly (0.05 greater than or equal to P greater than or equal to 0.001) higher than that found for sucrose in single-pass perfusion experiments. High-performance liquid chromatographic (HPLC) analysis showed that 95.6 +/- 3.6% of the effluent /sup 3/H radioactivity was attributable to bambuterol. In recirculating experiments (120 min) the lung biotransformation of /sup 3/H-bambuterol (8.5 pmol/ml) was studied. Both oxidative and hydrolytic metabolism took place. The dominating metabolites were hydroxylated bambuterol and the monocarbamate derivative which is a product of hydrolysis of bambuterol. Traces of terbutaline were also formed. The results show that bambuterol has a certain affinity to lung tissue and that the drug is, to some extent, biotransformed in the guinea pig lung.

  13. Characterization of gastrin receptors on guinea pig pancreatic acini

    SciTech Connect

    Yu, Dahong; Noguchi, Masato; Zhou, Zhichao; Villanueva, M.L.; Gardner, J.D.; Jensen, R.T. )

    1987-12-01

    Recent studies have demonstrated gastrin receptors in some pancreatic tumors and that gastrin is a potent stimulant of pancreatic Na{sup +}-H{sup +} exchange. In the present study the authors used {sup 125}I-labeled gastrin ({sup 125}I-gastrin) to characterize gastrin receptors on guinea pig pancreatic acini. Binding of {sup 125}I-gastrin was temperature dependent, saturable, and specific for gastrin-related peptides. Analysis demonstrated a single class of receptors with high affinity for gastrin and a binding capacity of 1 fmol/mg protein. Binding of {sup 125}I-gastrin was inhibited with the following relative potencies: cholecystokinin octapeptide (CCK-8) > gastrin-17-I = gastrin-34-I > pentagastrin > desulfated (des(SO{sub 3}))CCK-8 > CCK-4 and by the receptor antagonists CBZ-CCK-27-32-NH{sub 2} > proglumide analogue 10 > asperlicin > Bt{sub 2}-guanosine 3{prime},5{prime}-cyclic monophosphate. The present results demonstrate that guinea pig pancreatic acini possess gastrin receptors that have a high affinity for gastrin and are distinct from CCK receptors previously described. Only occupation of the CCK receptors results in enzyme secretion. Gastrin receptors on pancreatic acini resemble those described in parietal cells and gastric glands; however, their function is unknown.

  14. Evidence for independent evolution of functional progesterone withdrawal in primates and guinea pigs

    PubMed Central

    Nnamani, Mauris C.; Plaza, Silvia; Romero, Roberto; Wagner, Günter P.

    2013-01-01

    Background and objectives: Cervix remodeling (CRM) is a critical process in preparation for parturition. Early cervix shortening is a powerful clinical predictor of preterm birth, and thus understanding how CRM is regulated is important for the prevention of prematurity. Humans and other primates differ from most other mammals by the maintenance of high levels of systemic progesterone concentrations. Humans have been hypothesized to perform functional progesterone withdrawal (FPW). Guinea pigs are similar to humans in maintaining high-progesterone concentrations through parturition, thus making them a prime model for studying CRM. Here, we analyze the phylogenetic history of FPW and document gene expression in the guinea pig uterine cervix. Methodology: Data on progesterone withdrawal were collected from the literature, and character evolution was analyzed. Uterine cervix samples were collected from non-pregnant, mid-pregnant and late pregnant guinea pigs. RNA was extracted and sequenced. Relative transcript levels were estimated and compared among sample groups. Results: The phylogenetic analysis shows that FPW evolved independently in primates and guinea pigs. The transcriptome data confirms that guinea pigs down-regulate progesterone receptor toward parturition, in contrast to humans. Some of the similarities between human and guinea pig are: down-regulation of estrogen receptor, up-regulation of VCAN and IGFBP4 as well as likely involvement of prostaglandins. Conclusions and implications: (i) FPW in guinea pigs evolved independently from that in primates. (ii) A small set of conserved gene regulatory changes has been detected. PMID:24481205

  15. 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.

  16. Therapeutic efficacy of oral lactobacillus preparation for antibiotic-associated enteritis in guinea pigs.

    PubMed

    Wasson, K; Criley, J M; Clabaugh, M B; Koch, M A; Peper, R L

    2000-01-01

    Enteritis is a potential complication of antimicrobial agent use, particularly in certain species of rodents. The organism most frequently implicated in this disease is Clostridium difficile. Anecdotal information suggests that administration of yogurt or other Lactobacillus-containing products in conjunction with antimicrobial agents will prevent or minimize the effects of antibiotic-associated enteritis. We wanted to determine whether a single subcutaneous injection of clindamycin phosphate could induce enteritis in guinea pigs and whether a commercial Lactobacillus preparation would ameliorate the clinical effects of antibiotic administration in these animals. Juvenile male guinea pigs were divided into three treatment groups. Group 1 guinea pigs (n=8) received a single saline injection followed by an oral Lactobacillus preparation twice daily; group 2 (n=8) received a single antibiotic injection followed by an oral Lactobacillus preparation twice daily; group 3 (n=8) received a single antibiotic injection. Attitude, body temperature, body weight, and feed and water consumption were recorded for each guinea pig 7 days prior to and after treatment. Fecal samples were collected and necropsies performed on each guinea pig at the time of euthanasia. C. difficile and other enteric pathogens were not isolated from any group before or after treatment, although some guinea pigs receiving the antibiotic developed enteritis. There were no significant clinical differences between guinea pigs receiving antibiotics with the oral Lactobacillus preparation, and those receiving antibiotics alone. The results of this study suggest that a single injection of clindamycin phosphate can induce enteritis in guinea pigs and that oral administration of a Lactobacillus-containing product is ineffective in preventing clinical disease in guinea pigs administered clindamycin phosphate.

  17. 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

  18. Immunity to vaginal reinfection in female guinea pigs infected sexually with Chlamydia of guinea pig inclusion conjunctivitis.

    PubMed

    Lamont, H C; Semine, D Z; Leveille, C; Nichols, R L

    1978-03-01

    Guinea pig boars were inoculated intraurethrally with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). At the heights of their urethral infections, they were caged with sows in estrus. Whereas some of the sows had not been previously exposed to GPIC agent, others had received an intravaginal inoculation 5 to 8 weeks earlier. Those sows for which infected boars provided the first exposure were challenged by intravaginal inoculation 5 to 8 weeks later. Vaginal and conjunctival scrapings were taken regularly and stained for chlamydial inclusions. Titers of serum anti-GPIC antibodies and of vaginal secretory IgA anti-GPIC antibodies were determined by immunofluorescence. Our results show for the first time that a sexually acquired vaginal GPIC infection induces immunity to manual reinfection of the vagina. Because of the high incidence of secondary conjunctival infections among the vaginally infected sows, we could not provide a sound statistical basis for our tentative conclusion that manual infection of the vagina induces immunity to sexual reinfection. The results of our antibody titrations confirm previous work showing that vaginal GPIC infection induces formation of both serum antibody and vaginal secretory immunoglobulin A antibody.

  19. Lead acetate action on anaphylactic response of guinea pig smooth muscle.

    PubMed

    Gijón, E; Cartas, L; García, X

    2001-01-01

    Experiments were performed to evaluate lead acetate effects on the anaphylactic contraction in guinea pigs smooth muscles. Aortic rings from guinea pigs exposed to lead acetate developed an anaphylactic contraction significantly lower than the contraction induced by the antigen in controls. In the smooth muscle of the intestine, lead acetate did not modify the anaphylactic response. Lead induced immunosuppression of the anaphylactic response of aortic rings, whereas sodium acetate had no effect on the anaphylactic reaction of the guinea pig smooth muscle. The amplitude of the norepinephrine contraction was not modified by lead nor by sodium acetate.

  20. 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.

  1. 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

  2. Audiometric effects of simulated sonic booms in guinea pigs

    NASA Astrophysics Data System (ADS)

    Reinis, S.; Weiss, D. S.; Featherstone, J. W.; Tsaros, C.

    1987-03-01

    Changes of hearing thresholds have been studied in guinea pigs following exposure to 100 simulated sonic booms. Simulated sonic booms increased the hearing thresholds at frequencies above 30 kHz. The only early structural change observed was an appearance of a small blood clot in the scala tympani of the basal turn of the cochlea. Although these changes may be specific for small laboratory animals only, they indicate that caution is necessary in exposing people to repeated or intense sonic booms. Also, the data indicate that, following the exposure to the sonic booms, the high frequency hearing is influenced first. Therefore, audiometric testing following the sonic boom exposure should not be limited to the routine audiometric curve ending at 8 kHz.

  3. 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.

  4. Studies on contact hypersensitivity in the guinea pig.

    PubMed

    Tsuchiya, S; Kondo, M; Okamoto, K; Takase, Y

    1982-07-01

    A method to determine the quantitative induction and challenge of the allergenicity of externally applied toiletories and cosmetics, including their components, is described. The experiment used oil-soluble cinnamic aldehyde and water-soluble formalin as allergens, and guinea pigs as the experimental animals. A high sensitization method resulted, carried out as follows. A 24-h closed patch is attached to the skin every other day over a period of 2 weeks (a total of 4 applications). Freund's complete adjuvant is administered intradermally just before the 3rd application of the patch. The challenge step is performed by directly applying the test material. This method was compared with other allergenicity evaluation methods. As a result, this method was found to be in no way inferior in sensitization performance to the other methods. The method was used on perfume mixtures and tested for its evaluation effectiveness. It proved to be satisfactory.

  5. Assay of contact photosensitivity to musk ambrette in guinea pigs.

    PubMed

    Kochever, I E; Zalar, G L; Einbinder, J; Harber, L C

    1979-08-01

    This study reports the induction of contact photodermatitis to musk ambrette, 2-methoxy-3,5-dinitro-4-methyl-t-butylbenzene, in guinea pigs. Photoallergic contact dermatitis was assayed using 2 alternative induction methods. Successful photosensitization was achieved only when the nuchal skin was stripped with scotch tape before application of musk ambrette and ultraviolet radiation. Induction methods utilizing nonstripped nuchal skin which induce photosensitivity to potent photoallergens were ineffective for musk ambrette. Phtotoxicity tests to musk ambrette at concentrations between 1 and 50% and a dose of 10.2 joules/cm2 from "Black Light" fluorescent tubes were all negative. Under identical irradiation conditions, anthracene at 0.9% and 8-methoxypsoralen at 1% were consistently positive. The mechanism of photosensitivity to musk ambrette appears to be photoallergic rather than phototoxic. The requirement for skin abrasion to induce photosensitization parallels the clinical reports of photosensitivity to musk ambrette in man.

  6. Naegleria: another pathogenic ameba studies in germfree guinea pigs.

    PubMed

    Phillips, B P

    1974-09-01

    Free-living amebas of the genus Naegleria, of world-wide distribution and long considered harmless, have been linked etiologically with 57 fatal cases of primary amebic meningoencephalitis during the last decade. Naegleria from cultures derived from one of these fatal cases in Richmond, Virginia, have been inoculated intranasally, intraorally, into the conjunctival sac near the inner canthus of the eyes, and into induced skin lesions in adult germfree guinea pigs. Of 33 animals inoculated intranasally with 18 to 31 amebas, 31 developed a fatal encephalitis. There was considerable destruction of tissues of the cerebellum and the cerebrum and including the olfactory lobes. The meninges were involved to varying degrees in most of the animals. None of the animals inoculated by the three other routes developed either symptoms or lesions. PMID:4451226

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

    PubMed

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

    2011-12-01

    It has been demonstrated that 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.

  8. Interactions of trimebutine with guinea-pig opioid receptors.

    PubMed

    Roman, F; Pascaud, X; Taylor, J E; Junien, J L

    1987-05-01

    Affinities of trimebutine (TMB) and N-desmethyl trimebutine (NDTMB) for mu, delta and kappa opioid receptor subtypes have been examined using specific 3H-ligands and guinea-pig membrane. TMB and NDTMB showed a relative higher affinity for the mu receptor subtype although they were, respectively, 30- and 48-fold less active than morphine. The receptor selectivity index for mu, delta and kappa were 100:12:14.4 for TMB, 100:32:25 for NDTMB and 100:5:5 for morphine. The sodium shift ratio was 14 for TMB, 10 for NDTMB and 37 for morphine. These data show that (unlike morphine, a pure mu agonist) TMB and NDTMB can be classified as weak opioid agonists and confirm that peripheral opioid receptors mediate their gastrointestinal motility effects. PMID:2886594

  9. Oxygen radicals stimulate guinea pig gallbladder glycoprotein secretion in vitro

    SciTech Connect

    Hale, W.B.; Turner, B.; LaMont, J.T. )

    1987-11-01

    In several animal models of cholelithiasis, and in humans with gallstones, hypersecretion of gallbladder mucin is observed. This study was undertaken to determine the effect of oxygen radicals on guinea pig gallbladder glycoprotein secretion in organ culture. Mucosal explants were incubated with ({sup 3}H)glucosamine hydrochloride to label glycoproteins, then exposed to oxygen radicals generated by chelated ferric iron and ascorbic acid. Marked stimulation of glycoprotein release was observed after a 30-min exposure to the oxygen radical-generating system, and the effect was inhibited by mannitol. The stimulatory effect of hydroxyl radical was not accompanied by leakage of intracellular lactate dehydrogenase. Parallel experiments with human granulocytes activated with f-Met-Leu-Phe and coincubated with gallbladder explants revealed similar results. These results indicate that oxygen radicals, especially the hydroxyl radical (OH), are capable of stimulating rapid release of mucous-type glycoproteins from gallbladder epithelium.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  11. 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.

  12. 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

  13. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... lifting shall be provided on the exterior of the primary enclosure to enable the primary enclosure to be... guinea pig Weight (grams) Square centimeters Square inches Up to 350 193.6 30 350 to 600 290.3 45...

  14. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... lifting shall be provided on the exterior of the primary enclosure to enable the primary enclosure to be... guinea pig Weight (grams) Square centimeters Square inches Up to 350 193.6 30 350 to 600 290.3 45...

  15. Chronic estrogen exposure maintains elevated levels of progesterone receptor mRNA in guinea pig hypothalamus.

    PubMed

    Bayliss, D A; Millhorn, D E

    1991-05-01

    We performed in situ hybridization on hypothalamic sections from ovariectomized guinea pig using a cocktail of three 35S-labeled oligonucleotides complementary to mammalian progesterone receptor (PR) cDNA. PR mRNA was readily detected in hypothalamic neurons from guinea pigs pretreated with 17 beta-estradiol benzoate (E2B), but not from animals which did not receive supplemental E2B. The distribution of PR mRNA-containing cells corresponded well with previous localizations of PR in guinea pig. In contrast to earlier reports of E2B regulation of PR mRNA in rat hypothalamus, however, we found that PR mRNA remained elevated during chronic exposure to E2B (up to 10 days) in guinea pig. PMID:2072827

  16. Cortical representation of species-specific vocalizations in Guinea pig.

    PubMed

    Suta, Daniel; Popelář, Jiří; Burianová, Jana; Syka, Josef

    2013-01-01

    We investigated the representation of four typical guinea pig vocalizations in the auditory cortex (AI) in anesthetized guinea pigs with the aim to compare cortical data to the data already published for identical calls in subcortical structures - the inferior colliculus (IC) and medial geniculate body (MGB). Like the subcortical neurons also cortical neurons typically responded to many calls with a time-locked response to one or more temporal elements of the calls. The neuronal response patterns in the AI correlated well with the sound temporal envelope of chirp (an isolated short phrase), but correlated less well in the case of chutter and whistle (longer calls) or purr (a call with a fast repetition rate of phrases). Neuronal rate vs. characteristic frequency profiles provided only a coarse representation of the calls' frequency spectra. A comparison between the activity in the AI and those of subcortical structures showed a different transformation of the neuronal response patterns from the IC to the AI for individual calls: i) while the temporal representation of chirp remained unchanged, the representations of whistle and chutter were transformed at the thalamic level and the response to purr at the cortical level; ii) for the wideband calls (whistle, chirp) the rate representation of the call spectra was preserved in the AI and MGB at the level present in the IC, while in the case of low-frequency calls (chutter, purr), the representation was less precise in the AI and MGB than in the IC; iii) the difference in the response strength to natural and time-reversed whistle was found to be smaller in the AI than in the IC or MGB.

  17. 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.

  18. Guinea Pig Lung Lavage Cells After Intranasal BCG Sensitization

    PubMed Central

    Terai, T.; Ganguly, Rama; Waldman, Robert H.

    1979-01-01

    Recent studies have suggested that intranasal administration of antigen can induce local cell-mediated immunity in lung lavage cells. The present study was designed to examine the changes in composition of lung lavage cells and their capacity to produce the lymphokine migration inhibitory factor after intranasal immunization with BCG in guinea pigs. Results indicate that guinea pigs responded to respiratory tract BCG infection with an increase in immunocompetent cells in the bronchoalveolar tract and with production of migration inhibitory factor. After local pulmonary BCG administration, the total number of cells increased as compared with that of the uninfected animals, the increase being statistically significant within 2 weeks. This marked increase in the total cell population is due to a more than doubling of the number of macrophages in the lavage fluid. Animals also developed at this time positive delayed hypersensitivity to intradermally administered purified protein derivative. A significant increase in the total lymphoid cells and macrophage population was observed again at 6 weeks after sensitization, suggesting that the response is biphasic in nature. At 6 weeks, however, there was also a significant rise in total lymphocytes and T cell population in addition to macrophage numbers. This increase in T cells correlated with an increase in production of migration inhibitory factor in the presence of purified protein derivative. These data suggest that the immune response of the respiratory tract after BCG challenge involves increased recruitment of immunocompetent cells locally at the site of infection and that these cells are capable of producing effector molecules in terms of the elaboration of migration inhibitory factor. PMID:387595

  19. Processing of communication calls in Guinea pig auditory cortex.

    PubMed

    Grimsley, Jasmine M S; Shanbhag, Sharad J; Palmer, Alan R; Wallace, Mark N

    2012-01-01

    Vocal communication is an important aspect of guinea pig behaviour and a large contributor to their acoustic environment. We postulated that some cortical areas have distinctive roles in processing conspecific calls. In order to test this hypothesis we presented exemplars from all ten of their main adult vocalizations to urethane anesthetised animals while recording from each of the eight areas of the auditory cortex. We demonstrate that the primary area (AI) and three adjacent auditory belt areas contain many units that give isomorphic responses to vocalizations. These are the ventrorostral belt (VRB), the transitional belt area (T) that is ventral to AI and the small area (area S) that is rostral to AI. Area VRB has a denser representation of cells that are better at discriminating among calls by using either a rate code or a temporal code than any other area. Furthermore, 10% of VRB cells responded to communication calls but did not respond to stimuli such as clicks, broadband noise or pure tones. Area S has a sparse distribution of call responsive cells that showed excellent temporal locking, 31% of which selectively responded to a single call. AI responded well to all vocalizations and was much more responsive to vocalizations than the adjacent dorsocaudal core area. Areas VRB, AI and S contained units with the highest levels of mutual information about call stimuli. Area T also responded well to some calls but seems to be specialized for low sound levels. The two dorsal belt areas are comparatively unresponsive to vocalizations and contain little information about the calls. AI projects to areas S, VRB and T, so there may be both rostral and ventral pathways for processing vocalizations in the guinea pig. PMID:23251604

  20. Cortical representation of species-specific vocalizations in Guinea pig.

    PubMed

    Suta, Daniel; Popelář, Jiří; Burianová, Jana; Syka, Josef

    2013-01-01

    We investigated the representation of four typical guinea pig vocalizations in the auditory cortex (AI) in anesthetized guinea pigs with the aim to compare cortical data to the data already published for identical calls in subcortical structures - the inferior colliculus (IC) and medial geniculate body (MGB). Like the subcortical neurons also cortical neurons typically responded to many calls with a time-locked response to one or more temporal elements of the calls. The neuronal response patterns in the AI correlated well with the sound temporal envelope of chirp (an isolated short phrase), but correlated less well in the case of chutter and whistle (longer calls) or purr (a call with a fast repetition rate of phrases). Neuronal rate vs. characteristic frequency profiles provided only a coarse representation of the calls' frequency spectra. A comparison between the activity in the AI and those of subcortical structures showed a different transformation of the neuronal response patterns from the IC to the AI for individual calls: i) while the temporal representation of chirp remained unchanged, the representations of whistle and chutter were transformed at the thalamic level and the response to purr at the cortical level; ii) for the wideband calls (whistle, chirp) the rate representation of the call spectra was preserved in the AI and MGB at the level present in the IC, while in the case of low-frequency calls (chutter, purr), the representation was less precise in the AI and MGB than in the IC; iii) the difference in the response strength to natural and time-reversed whistle was found to be smaller in the AI than in the IC or MGB. PMID:23785425

  1. 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.

  2. 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.

  3. Pharmacokinetics of activated protein C in guinea pigs

    SciTech Connect

    Berger, H. Jr.; Kirstein, C.G.; Orthner, C.L. )

    1991-05-15

    Protein C is a vitamin K-dependent zymogen of the serine protease, activated protein C (APC), an important regulatory enzyme in hemostasis. In view of the potential of human APC as an anticoagulant and profibrinolytic agent, the pharmacokinetics and tissue distribution of APC were studied in guinea pigs. The plasma elimination of a trace dose of {sup 125}I-APC was biphasic following an initial rapid elimination of approximately 15% of the injected dose within 1 to 2 minutes. This rapid removal of {sup 125}I-APC from the circulation was found to be a result of an association with the liver regardless of the route of injection. Essentially identical results were obtained with active site-blocked forms of APC generated with either diisopropylfluorophosphate or D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone, which indicates that the active site was not essential for the liver association. Accumulation of all three forms of APC in the liver peaked at 30 minutes and then declined as increasing amounts of degraded radiolabeled material appeared in the gastrointestinal tract and urine. Removal of the gamma-carboxyglutamic acid (gla) domain of diisopropylphosphoryl-APC resulted in a 50% reduction in the association with liver and an accumulation in the kidneys. Protein C and protein S were cleared from the circulation at rates approximately one-half and one-fourth, respectively, that of APC. Both in vitro and in vivo, APC was found to form complexes with protease inhibitors present in guinea pig plasma. Complex formation resulted in a more rapid disappearance of the enzymatic activity of APC than elimination of the protein moiety. These findings indicate two distinct mechanisms for the elimination of APC. One mechanism involves reaction with plasma protease inhibitors and subsequent elimination by specific hepatic receptors. (Abstract Truncated)

  4. Ozone-induced modulation of airway hyperresponsiveness in guinea pigs.

    PubMed

    Schlesinger, Richard B; Cohen, Mitchell; Gordon, Terry; Nadziejko, Christine; Zelikoff, Judith T; Sisco, Maureen; Regal, Jean F; Ménache, Margaret G

    2002-06-01

    Although acute exposure to ozone (03*) has been shown to influence the severity and prevalence of airway hyperresponsiveness, information has been lacking on effects due to long-term exposure at relatively low exposure concentrations. The goals of this study were to determine whether long-term repeated ozone exposures could induce nonspecific hyperresponsiveness in normal, nonatopic (nonsensitized) animals, whether such exposure could exacerbate the preexisting hyperresponsive state in atopic (sensitized) animals, or both. The study was also designed to determine whether gender modulated airway responsiveness related to ozone exposure. Airway responsiveness was measured during and after exposure to 0.1 and 0.3 ppm ozone for 4 hours/day, 4 days/week for 24 weeks in normal, nonsensitized guinea pigs, in guinea pigs sensitized to an allergen (ovalbumin) prior to initiation of ozone exposures, and in animals sensitized concurrently with ozone exposures. Both male and female animals were studied. Ozone exposure did not produce airway hyperresponsiveness in nonsensitized animals. Ozone exposure did exacerbate airway hyperresponsiveness to specific and nonspecific bronchoprovocation in both groups of sensitized animals, and this effect persisted at least 4 weeks after the end of the exposures. Although the overall degree of airway responsiveness did differ between genders (males had more responsive airways than did females), the airway response to ozone exposure did not differ between the two groups. Ozone-induced effects upon airway responsiveness were not associated with the number of pulmonary eosinophils or with any chronic pulmonary inflammatory response. Levels of antigen-specific antibodies increased in sensitized animals, and a significant correlation was observed between airway responsiveness and antibody levels. The results of this study provide support for a role of ambient ozone exposure in exacerbation of airway dysfunction in persons with atopy.

  5. Immunologically induced neuromodulation of guinea pig nodose ganglion neurons.

    PubMed

    Undem, B J; Hubbard, W; Weinreich, D

    1993-07-01

    The influence of specific antigen challenge on the excitability of C-cells in nodose ganglia isolated from actively sensitized guinea pigs was evaluated using intracellular recording techniques. Antigen (ovalbumin) caused a significant depolarization (approximately 8 mV) of the resting membrane potential. Antigen exposure had differing effects on the membrane input impedance; decreasing it in 15 neurons, increasing it in 6 neurons, and having no effect in 8 neurons. About 20% of guinea pig nodose C-cells reveal a long-lasting after-spike hyperpolarization (AHPslow). Antigen challenge reversibly blocked the AHPslow in 4 of 18 neurons studied in 18 ganglia. About 30% of the nodose ganglion neurons display a time- and voltage-dependent inward rectification at membrane potentials more negative than -75 mV. Exposing the ganglion to the sensitizing antigen consistently blocked this response in 8 of 8 neurons. Histological assessment of toluidine blue stained cells revealed that the nodose ganglion contained approximately 100 mast cells. Exposing the ganglion to ovalbumin stimulated mast cell degranulation, as measured by a decrease in number of stained cells, and evoked the release of histamine, PGD2, and immunoreactive peptidoleukotrienes from the tissue. The results support the hypothesis that endogenous inflammatory mediators released during the immediate hypersensitivity (allergic) reactions can modulate the excitability of primary C-fiber afferents. Mechanisms underlying antigen-induced neuromodulation of these neurons include depolarization of the resting membrane potential, changes in membrane resistance, blockade of a time- and voltage-dependent anomalous rectifier, and, in some cells, blockade of the AHPslow.

  6. 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.

  7. 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.

  8. Immunisation of guinea-pigs with circulating immune complexes from patients with rheumatoid arthritis.

    PubMed

    Hack, C E; Lim, H G; Aalberse, R C

    1984-10-01

    Sixteen guinea-pigs were immunised with immune complexes isolated from serum of nine patients with rheumatoid arthritis. The resulting antisera were analysed by radioimmunoassays. All guinea-pig sera were extensively absorbed with normal human serum. After this absorption eight guinea-pig sera contained antibodies specific for immune complexes isolated from the sera of three patients. One of these antisera reacted not only with immune complexes (and serum) from the corresponding patient but also with immune complexes (and sera) from other patients with rheumatoid arthritis. The antigen(s) to which the guinea-pig antibodies were directed sedimented as IgM, and they bound to IgG Sepharose. Therefore the guinea-pig sera were absorbed with IgM-rheumatoid factors isolated from the serum of the corresponding patient. After this absorption, the guinea-pig sera had lost their reactivity with immune complexes. We conclude that these antisera did not detect an exogenous antigen in immune complexes from patients with rheumatoid arthritis. The positive reactions found were due to antibodies specific for (idiotypic?) antigenic determinants on IgM-rheumatoid factors.

  9. Pathogenesis of aerosolized Eastern Equine Encephalitis virus infection in guinea pigs

    PubMed Central

    Roy, Chad J; Reed, Douglas S; Wilhelmsen, Catherine L; Hartings, Justin; Norris, Sarah; Steele, Keith E

    2009-01-01

    Mice and guinea pigs were experimentally exposed to aerosols containing regionally-distinct strains (NJ1959 or ArgM) of eastern equine encephalitis virus (EEEV) at two exclusive particle size distributions. Mice were more susceptible to either strain of aerosolized EEEV than were guinea pigs; however, clinical signs indicating encephalitis were more readily observed in the guinea pigs. Lower lethality was observed in both species when EEEV was presented at the larger aerosol distribution (> 6 μm), although the differences in the median lethal dose (LD50) were not significant. Virus isolation and immunohistochemistry indicated that virus invaded the brains of guinea pigs within one day postexposure, regardless of viral strain or particle size distribution. Immunohistochemistry further demonstrated that neuroinvasion occurred through the olfactory system, followed by transneuronal spread to all regions of the brain. Olfactory bipolar neurons and neurons throughout the brain were the key viral targets. The main microscopic lesions in infected guinea pigs were neuronal necrosis, inflammation of the meninges and neuropil of the brain, and vasculitis in the brain. These results indicate that guinea pigs experimentally infected by aerosolized EEEV recapitulate several key features of fatal human infection and thus should serve as a suitable animal model for aerosol exposure to EEEV. PMID:19852817

  10. 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.

  11. 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.

  12. 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

  13. Viral strain dependent differences in experimental Argentine hemorrhagic fever (Junin virus) infection of guinea pigs.

    PubMed

    Kenyon, R H; Green, D E; Maiztegui, J I; Peters, C J

    1988-01-01

    Guinea pigs infected with low-passage Junin virus of human origin showed viral strain dependent differences in mortality, LD50, time to death, and in viral spread and distribution. Different Junin strains appeared to cause at least two broad patterns of Argentine hemorrhagic fever in guinea pigs. A number of strains of Junin virus caused a viscerotropic type of illness in which virus replicated predominantly in lymph nodes, spleen, and bone marrow. With the most severe visceral forms of Argentine hemorrhagic fever, the guinea pigs became viremic, developed necrosis of spleen, lymph nodes, and bone marrow, showed gastric hemorrhages, and all animals died within 13-15 days. Other Junin strains induced a neurological type of illness with transient viral replication in and lymphocyte depletion of spleen and lymph nodes, with no detectable viremia or viral replication in bone marrow. Subsequently, virus was found in the brain with varying severities of polioencephalitis, and the guinea pigs frequently showed rear leg paralysis before death occurred 28-34 days after inoculation. Not all animals infected with a neurotropic strain developed all these signs. One viral strain induced some signs characteristic of both patterns of illness. Although the disease forms in the guinea pig model did not strictly correlate with those observed in the humans from which these strains were obtained, the different strains of Junin virus consistently caused very different patterns of illness in infected guinea pigs.

  14. Immunosuppression of experimental allergic encephalomyelitis in guinea pigs by antibrain and antithymocyte heteroantisera.

    PubMed

    Rauch, H C; Tom, B H

    1980-01-01

    Experimental allergic encephalomyelitis (EAE), induced by central nervous system (CNS) myelin basic protein (MBP) in adjuvant, is considered a thymus dependent autoimmune disease. Brain contains the thymic antigen, thy 1. The possibility that brain associated anti thy 1 immunoglobulin may be provoked in certain pathologic conditions of the CNS suggested a comparative evaluation of brain and thymocyte antisera on the development of EAE. Antisera produced in rabbits against brain from guinea pigs, rats and mice or fetal guinea pig thymus were highly reactive against thy 1 containing cells when assessed by indirect immunofluorescent staining or complement-mediated cell lysis. Treatment of guinea pigs with heteroantisera to guinea pig and mouse, but not to rat brain, for 3 days around the time of MBP sensitization markedly reduced physical signs of disease, particularly paralysis, but had little effect on the development of inflammatory lesions in the CNS. Anti-guinea pig thymocyte sera eliminated all physical signs of EAE with only residual pathology. These results establish the relative immunosuppressive effect of brain and thymocyte antisera in EAE and corroborate the thymus-dependent nature of EAE in guinea pigs.

  15. 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

  16. 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.

  17. 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.

  18. T-cell-activating monoclonal antibodies, reacting with both leukocytes and erythrocytes, recognize the guinea pig Thy-1 differentiation antigen: characterization and cloning of guinea pig CD90.

    PubMed

    Schäfer, H; Bartels, T; Hahn, G; Otto, A; Burger, R

    1999-11-01

    A glycophosphatidylinositol (GPI)-linked differentiation antigen expressed on guinea pig T and B lymphocytes was identified by several monoclonal antibodies; it has been shown previously that this membrane protein induced strong polyclonal T cell proliferation upon antibody binding and costimulation by PMA. Purification by immunoadsorption and microsequencing revealed that this T-cell-activating protein is the homologue of Thy-1 or CD90. In contrast to the Thy-1 antigen of most other species, guinea pig Thy-1 has a much higher molecular weight, which is due to a more extensive N-linked glycosylation, bringing the molecular weight of the total antigen up to 36 kDa. Molecular cloning of guinea pig Thy-1 indicated that the deduced molecular weight of the protein backbone is 12,777 after removal of an N-terminal 19-amino-acid leader peptide and cleavage of the 31 amino acids for GPI anchoring the C-terminal end. Sequence comparison showed that guinea pig Thy-1 has an 82% homology to human and a 72% homology to mouse Thy-1 on the amino acid level. Immunohistological staining of cryostat sections revealed intensive staining with the monoclonal antibody H154 on fibroblasts, fibrocytes, Kupffer cells, alveolar macrophages, and mesangial cells. As observed in the human, mouse, and rat, Thy-1 is abundant in the guinea pig brain. Unlike Thy-1 expression in other species, guinea pig Thy-1 is strongly expressed on most resting, nonactivated B cells and, to a lesser extent, on erythrocytes. While treatment of erythrocytes and lymphocytes with GPI-specific phospholipase C largely decreased reactivity with mAb H154, T cells retained the proliferative response to antibody and phorbol esters.

  19. 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.

  20. Effect of KOB03, a polyherbal medicine, on ovalbumin-induced allergic rhinitis in guinea pigs

    PubMed Central

    2012-01-01

    Background KOB03 is a polyherbal medicine that originated from the oriental prescription for the treatment of chronic allergic diseases such as rhinitis and asthma. This study aims to evaluate the effect of KOB03 on ovalbumin (OVA)-induced allergic rhinitis (AR) in guinea pigs. Methods Hartley guinea pigs were sensitized to OVA by intraperitoneal injection on days 0, 7, and 14 and challenged with intranasal exposure to OVA three times for 7 days after the last sensitization. KOB03 at doses of 200 and 500 mg/kg were orally administrated to guinea pigs once daily during challenge. The serum levels of histamine, OVA-specific immunoglobulin (Ig) E, eosinophil cationic protein (ECP) and cytokines (TNF-α, IL-4 and IFN-γ) in OVA sensitization/challenge-induced AR guinea pigs were measured. We also observed histological changes in nasal tissues of AR guinea pigs by staining with H&E, Periodic acid-Schiff, and toluidine blue. Results The administration of KOB03 at a dose of 500 mg/kg significantly decreased the serum levels of histamine (P = 0.001), OVA-specific IgE (P = 0.0017), ECP (P = 0.008), and TNF-α (P = 0.0003) in OVA-sensitized/challenged guinea pigs compared with controls. KOB03 significantly decreased the serum levels of a Th2 cytokine, IL-4 (P = 0.017), while significantly increasing the levels of a Th1 cytokine, IFN-γ (P = 0.0006) in OVA-sensitized/challenged guinea pigs compared with controls. In addition, KOB03 suppressed the epithelial destruction, goblet cell hyperplasia and eosinophilic infiltration into nasal mucosa associated with AR. Conclusion KOB03 may regulate allergic inflammation in AR by inhibiting nasal damage, the release of allergic mediators and modulating the balance of Th1/Th2 cytokines. PMID:23253436

  1. Acoustic stimulation promotes DNA fragmentation in the Guinea pig cochlea.

    PubMed

    Kamio, Tomonobu; Watanabe, Ken-Ichi; Okubo, Kimihiro

    2012-01-01

    Apoptosis can be described as programmed cell death. Apoptosis regulates cell turnover and is involved in various pathological conditions. The characteristic features of apoptosis are shrinkage of the cell body, chromatin condensation, and nucleic acid fragmentation. During apoptosis, double-stranded DNA is broken down into single-stranded DNA (ssDNA) by proteases. Acoustic trauma is commonly encountered in otorhinolaryngology clinics. Intense noise can cause inner ear damage, such as hearing disturbance, tinnitus, ear fullness, and decreased speech discrimination. In this study, we used immunohistochemical and electrophysiological methods to examine the fragmentation of DNA in the cochleas of guinea pigs that had been exposed to intense noise. Twenty-four guinea pigs weighing 250 to 350 g were used. The animals were divided into 4 groups: (I) a control group (n=6), (II) a group that was exposed to noise for 2 hours (n=6), (III) a group that was exposed to noise for 5 hours (n=6), and (IV) a group that was exposed to noise for 20 hours. The stimulus was a pure tone delivered at a frequency of 2 kHz. The sound pressure level was 120 dBSPL. No threshold shifts were apparent in group I. Group II showed a significant elevation of the hearing threshold (ANOVA, p<0.05(*)). The ABR threshold level was also significantly elevated immediately after the acoustic stimulation in groups III and IV (ANOVA, p<0.01(**)). In groups I, II, and IV, the lateral wall of the ear did not show immunoreactivity to ssDNA but did in group III. No immunoreactivity was apparent in the organ of Corti in group I or II. However, the supporting cells and outer hair cells in groups III and IV showed reactions for ssDNA. The fine structure of the organ of Corti had been destroyed in group IV. The lateral wall showed immunoreactivity for ssDNA only in group III, whereas the organ of Corti showed reactions for ssDNA in groups III and IV. Our study suggests that apoptotic changes occur in patients that

  2. Acoustic stimulation promotes DNA fragmentation in the Guinea pig cochlea.

    PubMed

    Kamio, Tomonobu; Watanabe, Ken-Ichi; Okubo, Kimihiro

    2012-01-01

    Apoptosis can be described as programmed cell death. Apoptosis regulates cell turnover and is involved in various pathological conditions. The characteristic features of apoptosis are shrinkage of the cell body, chromatin condensation, and nucleic acid fragmentation. During apoptosis, double-stranded DNA is broken down into single-stranded DNA (ssDNA) by proteases. Acoustic trauma is commonly encountered in otorhinolaryngology clinics. Intense noise can cause inner ear damage, such as hearing disturbance, tinnitus, ear fullness, and decreased speech discrimination. In this study, we used immunohistochemical and electrophysiological methods to examine the fragmentation of DNA in the cochleas of guinea pigs that had been exposed to intense noise. Twenty-four guinea pigs weighing 250 to 350 g were used. The animals were divided into 4 groups: (I) a control group (n=6), (II) a group that was exposed to noise for 2 hours (n=6), (III) a group that was exposed to noise for 5 hours (n=6), and (IV) a group that was exposed to noise for 20 hours. The stimulus was a pure tone delivered at a frequency of 2 kHz. The sound pressure level was 120 dBSPL. No threshold shifts were apparent in group I. Group II showed a significant elevation of the hearing threshold (ANOVA, p<0.05(*)). The ABR threshold level was also significantly elevated immediately after the acoustic stimulation in groups III and IV (ANOVA, p<0.01(**)). In groups I, II, and IV, the lateral wall of the ear did not show immunoreactivity to ssDNA but did in group III. No immunoreactivity was apparent in the organ of Corti in group I or II. However, the supporting cells and outer hair cells in groups III and IV showed reactions for ssDNA. The fine structure of the organ of Corti had been destroyed in group IV. The lateral wall showed immunoreactivity for ssDNA only in group III, whereas the organ of Corti showed reactions for ssDNA in groups III and IV. Our study suggests that apoptotic changes occur in patients that

  3. Ouabain uptake by endocytosis in isolated guinea pig atria

    SciTech Connect

    Nunez-Duran, H.; Riboni, L.; Ubaldo, E.; Kabela, E.; Barcenas-Ruiz, L. Instituto Nacional de Cardiologia, Mexico DF )

    1988-10-01

    Mammalian cells specifically internalize some molecular species through receptor-mediated endocytosis (RME). The authors have used four different experimental protocols to investigate whether ouabain enters cardiac cells of guinea pig atrium through this pathway. First, by electron microscope morphometry the authors found that ouabain increased endocytic vesicles in atrial cells. Second, by scintillation counting they found that ({sup 3}H)ouabain uptake by the tissue is decreased by three treatments that decrease RME, i.e., NH{sub 4}Cl, trifluoperazine, and 16 mM (K{sup +}){sub 0}. Third, by radioautography at the electron microscope level, they checked that in preceding experiments ({sup 3}H)ouabain was washed out of plasma membrane after 60-min rinse and interiorized into the cardiac cells. Fourth, isometric tension recordings showed that the positive inotropic effect of ouabain was diminished in the presence of inhibitors, whereas that of a hydrophobic analogue, ouabagenin, was not affected. These results suggest that ouabain enters cardiac cells through RME and also that an intracellular site may, at least in part, be responsible for its inotropic effect.

  4. Absorption Kinetics of Subcutaneously Administered Ceftazidime in Hypoperfused Guinea Pigs

    PubMed Central

    Ebihara, Tsuyoshi; Oshima, Shinji; Okita, Mitsuyoshi; Shiina, Sayumi; Negishi, Akio; Ohara, Kousuke; Ohshima, Shigeru; Iwasaki, Hiroyuki; Yoneyama, Akira; Kitazumi, Eiji; Kobayashi, Daisuke

    2014-01-01

    Background Pneumonia is the most common cause of death in patients with severe motor and intellectual disabilities (SMID), and intravenous ceftazidime (CAZ) is a widely used treatment for such infections. However, intravenous administration in patients with SMID may be difficult because of insufficient vascular development. Objectives The aim of our study was to determine the feasibility of subcutaneous drug administration by mentholated warm compresses (WMCs) as an alternative delivery method for ceftazidime in patients with SMID. Methods CAZ was subcutaneously administered to the abdominal region of naphazoline-treated hypoperfused guinea pigs, which were used as a hemodynamic model of patients with SMID. MWCs or warm compresses (WCs) were applied to the injection site to increase blood flow. We calculated the cumulative CAZ absorption over time by using the deconvolution method. Results Application of MWCs or WCs increased blood flow at the administration site and increased CAZ plasma levels. Application of MWCs or WCs after subcutaneous CAZ injection led to higher CAZ plasma levels than the mutant prevention concentration for a longer period than was observed for CAZ administration without the application of MWCs or WCs. Conclusions The application of MWCs or WCs enhanced subcutaneous CAZ absorption by increasing blood flow. MWCs and WCs are considered to be safe and routine methods to induce defecation after surgery on the digestive system; thus, the combination of these methods and subcutaneous CAZ administration is a potential method for treating pneumonia in patients with SMID. PMID:26649076

  5. Visual evoked potentials in guinea pigs with brain lesion.

    PubMed

    Takeuchi, T; Suzuki, M; Sitizyo, K; Isobe, R; Saito, T; Umemura, T; Shimada, A

    1992-10-01

    Visual evoked potentials (VEPs) were recorded in 10 adult male guinea pigs with brain lesion. Lesions were produced in 5 animals by superficial suction of the occipital lobe. The other 5 animals were orally administered with hexachlorophene (about 35 mg/kg/day) for 28 days. In the VEP following the ablation of the occipital lobe, the peaks P10, N20, P55, N75, N140 and P200 disappeared in many cases. The amplitude of the peak N40 decreased to approximately one half its control VEP. In the VEP obtained from the animals administered with hexachlorophene, the peak latencies of N20, P30, P55, N75 and P100 were slightly prolonged after the 7th day following the first administration. On the other hand, there was no change in the latency of N40 during the whole period of administration. The peak-to-peak amplitude showed some variability in different peaks. Histologically, diffuse status spongiosis were found in the white matter of the cerebrum, cerebellum, and brain stem. As described above, the ablation of the occipital lobe caused markedly depressed VEPs, however, the responses to the photic stimulation persisted after the injury. On the other hand, the VEPs of animals administered with hexachlorophene showed a high probability of peak appearance, and a decrease in amplitude was not marked.

  6. 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.

  7. Transport of cyanide into guinea pig cardiac mitochondria.

    PubMed

    Wisler, J A; Dulaney, M D; Pellicore, L S; Lenz, D E

    1991-05-01

    The transport of cyanide (CN) into cells has been presumed to be by passive diffusion. Recently, there have been reports that CN, in the form of an anion, may enter the cell by active or facilitated transport. To characterize the mechanism(s) and kinetics of CN movement across the cell membrane, we measured the rate of 14CN (Na salt) uptake into guinea-pig mitochondria. Initial velocities of CN movement into mitochondria were determined at time points ranging from 10-100 msec and at CN concentrations ranging from 1 microM-10 mM using a rapid filtration device. A Hofstee plot of the data suggests that an active or facilitated transport predominates at lower CN concentrations (less than 10 microM), whereas passive diffusion of CN predominates at higher CN concentrations. The kinetic constants for the active phase transport were Jmax = 0.9 pmol/ms and Kt = 14 microM. These results suggest that a large portion of CN movement across the cell membrane is due to an active or facilitated transport phenomenon.

  8. Cross-links between stereocilia in the guinea pig cochlea.

    PubMed

    Furness, D N; Hackney, C M

    1985-05-01

    Cross-links between stereocilia on guinea pig cochlear hair cells have been examined using high resolution scanning (SEM) and transmission electron microscopy (TEM), confirming recent descriptions of these structures. Links from the tips of shorter stereocilia to the sides of the adjacent taller stereocilia (upward-pointing links), between stereocilia of the same row (side-to-side links) and between adjacent rows (row-to-row links), have been observed on inner and outer hair cells. These links have been seen in material fixed using (1) glutaraldehyde only, (2) glutaraldehyde/osmium and (3) glutaraldehyde/osmium/thiocarbohydrazide (a technique which makes gold coating unnecessary). Upward-pointing links were seen less frequently, and the surfaces of stereocilia and microvilli were smoother after fixation (3) compared with fixations (1) and (2) in which they were usually roughened in appearance. In TEM, side-to-side and row-to-row links form a regular lattice between stereocilia, and consist of a number of strands. Upward-pointing links consist of a single strand, the ends of which are associated with electron-dense material. This lies between the stereociliary membrane and the actin filament bundle, at the tip of the shorter stereocilium and the side of the taller stereocilium.

  9. 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.

  10. 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.

  11. [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.

  12. Biosynthesis of glucagon in isolated pancreatic islets of guinea pigs

    PubMed Central

    Hellerström, Claes; Howell, Simon L.; Edwards, John C.; Andersson, Arne; Östenson, Claes-Göran

    1974-01-01

    1. The biosynthesis of glucagon in guinea-pig A2 cells was investigated by incubation of isolated islets of Langerhans in the presence of [3H]tryptophan for periods of up to 14 days. Proteins were extracted from islets and incubation media and analysed by gel filtration. 2. In addition to very-high-molecular-weight (100000) proteins, the principal tryptophan-containing biosynthetic product after incubation for up to 17h was a protein of minimum mol.wt. 9000, which co-eluted on gel filtration with a peak of glucagon-like immunoreactivity, but was apparently devoid of biological activity in a fat-cell assay. A discrete peak of labelled glucagon was only recovered after incubation for at least 6 days. Losses of glucagon during the extraction and rapid secretion of newly synthesized glucagon into incubation media were excluded as reasons for the lack of recovery of labelled hormone from islets after shorter incubations. 3. The 9000-mol.wt. protein was localized to A2 cells in experiments using B-cell-depleted islets, and to A2-cell granules by subcellular fractionation and electron-microscopic radioautography. Only glucagon was secreted into the incubation medium. 4. Possible relationships between the 9000-mol.wt. protein and glucagon are discussed in the light of postulated mechanisms of glucagon biosynthesis. PMID:4615708

  13. A plant histaminase modulates cardiac anaphylactic response in guinea pig.

    PubMed

    Masini, Emanuela; Vannacci, Alfredo; Marzocca, Cosimo; Mannaioni, Pier Francesco; Befani, Olivia; Federico, Rodolfo; Toma, Alessandro; Mondovì, Bruno

    2002-08-30

    The effect of a copper amine oxidase (histaminase) purified from the pea seedling as free or immobilized enzyme on the response to specific antigen was studied in isolated hearts from actively sensitized guinea pigs. In vitro challenge with the specific antigen of hearts from actively sensitized animals evokes a positive inotropic and chronotropic effect, a coronary constriction, followed by dilation and an increase in the amount of histamine and nitrites, the oxidation product of nitric oxide, in the perfusates. In the presence of both forms of histaminases, the positive inotropic and chronotropic responses as well as the coronary constriction and the release of histamine were fully blocked. The amount of nitrites, appearing in the perfusates when anaphylaxis is elicited in the presence of both forms of histaminases, is significantly increased, as well as nitric oxide synthase activity and cyclic GMP content in cardiac tissue, while cardiac calcium overload was significantly prevented. These observations demonstrate that the decrease in the anaphylactic release of histamine and the subsequent abatement of the cardiac response to antigen can be accounted for by the inactivation by histaminase of the released histamine and by a stimulation of endogenous nitric oxide production. PMID:12200124

  14. Gene Targeting to the Uteroplacental Circulation of Pregnant Guinea Pigs.

    PubMed

    Mehta, Vedanta; Ofir, Keren; Swanson, Anna; Kloczko, Ewa; Boyd, Michael; Barker, Hannah; Avdic-Belltheus, Adnan; Martin, John; Zachary, Ian; Peebles, Donald; David, Anna L

    2016-08-01

    Our study aimed to target adenoviral gene therapy to the uteroplacental circulation of pregnant guinea pigs in order to develop a novel therapy for fetal growth restriction. Four methods of delivery of an adenovirus encoding β-galactosidase (Ad.LacZ) were evaluated: intravascular injection using phosphate-buffered saline (PBS) into (1) uterine artery (UtA) or (2) internal iliac artery or external administration in (3) PBS or (4) pluronic F-127 gel (Sigma Aldrich). Postmortem examination was performed 4 to 7 days after gene transfer. Tissue transduction was assessed by X-gal histochemistry and enzyme-linked immunosorbent assay. External vascular application of the adenovirus vector in combination with pluronic gel had 91.7% success rate in terms of administration (85% maternal survival) and gave the best results for maternal/fetal survival and local transduction efficiency without any spread to maternal or fetal tissues. This study suggests an optimal method of gene delivery to the UtAs of a small rodent for preclinical studies.

  15. 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

  16. 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.

  17. 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. PMID:381262

  18. Reduced noise susceptibility in littermate offspring from heterozygous animals of the German waltzing guinea pig.

    PubMed

    Skjönsberg, Åsa; Mannström, Paula

    2015-07-01

    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.

  19. Reduced noise susceptibility in littermate offspring from heterozygous animals of the German waltzing guinea pig.

    PubMed

    Skjönsberg, Åsa; Mannström, Paula

    2015-07-01

    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. PMID:26053702

  20. 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

  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. 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

  3. Enhancement of the responsiveness of vas deferens and ileum smooth muscle in sensitized guinea pigs: in vitro study.

    PubMed

    Bidon, J C; Blin, M; Gogny, M; Vu, A T; Jondet, A

    1994-05-01

    Changes in the reactivity of the ileum (to histamine and barium chloride) and vas deferens (to acetylcholine and barium chloride), isolated from actively egg albumen-sensitized guinea pigs, have been investigated. The study was performed on 2 guinea pig strains: the Dunkin-Hartley strain, usually used as an airway allergic model, and the BFA strain. In actively sensitized guinea pigs of both strains, concentration-response curves exhibited a significant dose-dependent upward shift compared to those obtained in control guinea pigs. The maximal contraction strength calculated from these curves was significantly enhanced in both sensitized guinea pig strains, without a change in EC50 values. This study showed that the active antigen sensitization procedure involved several smooth muscle functions, and not exclusively the trachea. PMID:7950408

  4. Respiration and glucose oxidation in human and guinea pig leukocytes: comparative studies

    PubMed Central

    Baehner, Robert L.; Gilman, Neal; Karnovsky, Manfred L.

    1970-01-01

    A comparison has been made of the metabolic shifts in human and guinea pig leukocytes when they phagocytize. Respiration of guinea pig polymorphonuclear leukocytes (PMN) and the increment during phagocytosis were each about 2½-fold that of human PMN. This was also true of the direct oxidation of glucose-6-P (hexose monophosphate shunt). Enzymes potentially responsible for these phenomena have been compared in each species. Cyanide-insensitive NADH oxidase and NADPH oxidase were measured and only the formed exhibited adequate activity to account for the respiratory stimulus durintg phagocytosis. The hydrogen peroxide formed by this enzyme stimulates the hexose monophosphate shunt by oxidizing glutathione which upon reduction by an NADPH-linked glutathione reductase provides NADP to drive the hexose monophosphate shunt. Other linkages between respiratory stimulation and that of the hexose monophosphate shunt also pertain in the guinea pig. PMID:4392648

  5. Influence of body condition on reproductive output in the guinea pig.

    PubMed

    Michel, Catherine Louise; Bonnet, Xavier

    2012-01-01

    Reproduction is expensive. Substantial body reserves (i.e. high body condition) are usually required for females to undertake offspring production. In many vertebrates, maternal body condition positively influences reproductive output, and emaciated individuals skip reproduction. However, the impact of extremely high body condition, more specifically obesity, on animal reproductive performance remains poorly understood and research has generated contradictory results. For instance, obesity negatively affects fertility in women, but does not influence reproductive capacity or reproductive output in laboratory rodents. We examined the influence of high body condition on reproductive status and reproductive output in the guinea pig. In captivity, when fed ad libitum, guinea pigs store large amounts of fat tissues and exhibit a tendency for obesity. Our results show that obesity negatively affected reproduction in this species: both the proportion of fertile females and litter size were lower in the fattest females. Therefore, guinea pigs may represent suitable organisms to better understand the negative effect of obesity on reproduction.

  6. Chronic prenatal ethanol exposure increases disinhibition and perseverative responding in the adult guinea pig.

    PubMed

    Olmstead, Mary C; Martin, Amanda; Brien, James F; Reynolds, James N

    2009-09-01

    Cognitive and behavioural deficits, including increased impulsivity and perseveration, are associated with chronic prenatal ethanol exposure (CPEE) in humans. We tested whether these same deficits occur in the guinea pig after CPEE treatment. Pregnant guinea pigs received oral administration of ethanol (4 g/kg maternal body weight/day), or isocaloric-sucrose/pair-feeding throughout gestation. Young adult offspring were trained in lever-pressing paradigms to work for a sucrose-pellet food reward. CPEE increased No-Go, but not Go, responses in the Go/No-Go paradigm, indicative of a disinhibition deficit in these animals. Perseverative responses in the Cued Alternation task were also increased in CPEE offspring. These data show that CPEE induces behavioural deficits in the guinea pig that are remarkably similar to the executive function deficits that follow prenatal ethanol exposure in humans.

  7. 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.

  8. Resistance to reinfection with a chlamydial agent (guinea pig inclusion conjunctivitis agent).

    PubMed

    Ahmad, A; Dawson, C R; Yoneda, C; Togni, B; Schachter, J

    1977-06-01

    Although most chlamydial infections are chronic or recurrent, infection of the guinea pig's eye with guinea pig inclusion conjunctivitis (GPIC) agent induces a marked resistance to reinfection. To characterize this resistance to GPIC agent, we compared the disease and infection in previously infected guinea pigs with that in animals infected for the first time. In animals experiencing primary infection, even the lowest dose (10 egg-lethal doses [ELD50]) produced the disease and chlamydial inclusions in conjunctival smears, but the incubation period became progressively shorter with the highest inocula (10(4) and 10(5) ELD50). In animals with previous infection only these two highest inocula produced disease and infection, but the disease was short-lived, and replication of the agent was severely limited. The mechanism of this resistance may be due to secretory antibody in the tears, cellular immunity, or other local factors.

  9. Cystitis associated with chlamydial infection of the genital tract in male guinea pigs.

    PubMed

    Rank, R G; White, H J; Soloff, B L; Barron, A L

    1981-01-01

    Male guinea pigs were infected with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC) by intraurethral injection of chlamydiae or by placement of a drop of chlamydial suspension on the meatus of the extruded penis. Transient urethritis and cystitis were observed in animals infected by either method. The production of cystitis by the drop-on technique indicated that chlamydiae are able to ascend the urethra and that the bladder may be a target organ of chlamydial infection. When infected animals were immunosuppressed with cyclophosphamide, the number of guinea pigs with cystitis was increased, and chlamydiae could be detected in the bladder for as long as 50 days after infection. In contrast, GPIC was not detected in the bladders of untreated animals after day 18.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Differences in the distribution and characteristics of tachykinin NK1 binding sites between human and guinea pig lung.

    PubMed Central

    Walsh, D A; Salmon, M; Featherstone, R; Wharton, J; Church, M K; Polak, J M

    1994-01-01

    1. The distribution and characteristics of tachykinin NK1 binding sites have been compared in human and guinea pig lung using quantitative in vitro receptor autoradiography with [125I]-Bolton Hunter-labelled substance P ([125I]-BH-SP). In addition, the effects on these sites of ovalbumin sensitization and challenge have been determined in guinea pig lung. 2. [125I]-BH-SP bound specifically and with high affinity to microvascular endothelium in both human and guinea pig lung, but to bronchial smooth muscle and pulmonary artery media in only guinea pig lung. 3. Specific binding of [125I]-BH-SP to guinea pig bronchial smooth muscle was positively correlated with airway diameter in the range 150-800 microns and was less dense in trachea than in main bronchi. 4. [125I]-BH-SP binding was inhibited by tachykinins with rank orders of affinity of SP > NKA > NKB (human microvessels) and SP > NKA = NKB (guinea pig bronchi and pulmonary arteries). NKA displayed a higher affinity for [125I]-BH-SP binding sites in human microvessels than in guinea pig tissues (P < 0.0001), indicating differences in selectivity for tachykinins between human and guinea pig NK1 receptors. 5. In both human and guinea pig lung, [125I]-BH-SP binding was inhibited by the specific tachykinin receptor antagonists FK888 (NK1 selective antagonist) and FK224 (mixed NK1/NK2 antagonist), with FK888 displaying equal affinity to SP and > 500 times higher affinity than FK224. SP, NKA, NKB and FK888 exhibited similar affinities for [125I]-BH-SP binding sites in both guinea pig arteries and bronchi.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 Figure 2 PMID:7534186

  15. Apparent lack of beta 3-adrenoceptors and of insulin regulation of glucose transport in brown adipose tissue of guinea pigs.

    PubMed

    Himms-Hagen, J; Triandafillou, J; Begin-Heick, N; Ghorbani, M; Kates, A L

    1995-01-01

    Norepinephrine-induced thermogenesis was substantial in adipocytes from brown adipose tissue (BAT) of cold-acclimated guinea pigs but absent in adipocytes from BAT of warm-acclimated guinea pigs. There was no thermogenic response to any beta 3-adrenergic agonist (CL-316,243, ZD-7114, BRL-28410, CGP-12177). The receptor was characterized as a beta 1-adrenoceptor. Adrenergic agonists stimulated adenylate cyclase in membranes from BAT of both warm- and cold-acclimated guinea pigs also via a beta 1-adrenoceptor; beta 3-adrenergic agonists had no effect. Glucose transport by brown adipocytes from warm-acclimated guinea pigs was not stimulated by either norepinephrine or insulin. Cold acclimation induced the appearance of stimulation of glucose transport by norepinephrine in association with the appearance of a large capacity for thermogenesis, but there was little improvement in response to insulin. GLUT4 was present in membranes from BAT of both warm- and cold-acclimated guinea pigs. Insulin is known to have an antilipolytic effect on both BAT and white adipose tissue of guinea pigs. Thus there is a selective lack of insulin-regulated glucose transport that is not improved by cold acclimation. Guinea pigs may have a mutated component of the translocation mechanism for GLUT4. beta 3-Adrenoceptors appear to be absent in brown adipocytes of adult guinea pigs, as in white adipocytes of guinea pigs, yet are known to be present in the gut. Tissue-specific expression of beta 3-adrenergic receptors in guinea pigs may differ from that in rats, in which receptors are expressed in the adipose tissues and gut. PMID:7840345

  16. Purification and characterization of guinea pig liver morphine 6-dehydrogenase.

    PubMed

    Yamano, S; Kageura, E; Ishida, T; Toki, S

    1985-05-10

    Morphine 6-dehydrogenase, which catalyzes the dehydrogenation of morphine to morphinone, has been purified about 440-fold from the soluble fraction of guinea pig liver with a yield of 38%. The purified enzyme was a homogeneous protein on polyacrylamide gel disc electrophoresis and isoelectric focusing. The molecular weight and isoelectric point of the enzyme were 29,000 and 7.6, respectively. The enzyme utilizes both NAD and NADP as a cofactor, and the Km values were 0.12 mM for NAD and 0.42 mM for NADP. The Vmax values for morphine were 588 milliunits/mg of protein (with NAD) and 1600 milliunits/mg of protein (with NADP). The Km values for morphine were 0.12 mM (with NAD) and 0.49 mM (with NADP). The enzyme also exhibited activity for morphine-related compounds: nalorphine, normorphine, codeine, and ethylmorphine; however, 7,8-saturated congeners such as dihydromorphine and dihydrocodeine were poor substrates. The enzyme was inactivated by removal of 2-mercaptoethanol from the enzyme solution. The inactivated enzyme was rapidly recovered by the addition of 2-mercaptoethanol. Phenylarsine oxide and CdCl2 (dithiol modifiers) inhibited competitively toward cofactor binding and noncompetitively toward morphine binding. These results suggest that the enzyme possesses the essential thiol groups, probably vicinal dithiol, at or near the cofactor-binding site. Using the partially purified enzyme, 8-(2-hydroxyethylthio)dihydromorphinone was isolated as the product and identified by UV, mass, and NMR spectra. It was confirmed that morphinone proposed as the dehydrogenation product was nonenzymatically and covalently bound to 2-mercaptoethanol. Accordingly, the isolated morphinone-2-mercaptoethanol conjugate must be formed by two steps: enzymatic production of morphinone from morphine and then nonenzymatic binding of 2-mercaptoethanol to morphinone. PMID:2580834

  17. 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.

  18. [+]-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.

  19. Vagal non-adrenergic inhibition of guinea-pig stomach

    PubMed Central

    Beani, L.; Bianchi, Clementina; Crema, A.

    1971-01-01

    1. The effect of vagal and sympathetic stimulation on the mechanical and electrical activity (intracellular recording) of the body of the guinea-pig stomach was investigated in vitro. 2. Following atropine, 1 × 10-6-1 × 10-7 g/ml., vagal responses were reversed from excitatory to inhibitory. 3. Sympathetic blockade, produced by α- and β-receptor antagonists and adrenergic neurone-blocking agents, reduced or abolished sympathetic, but not vagal inhibition. 4. Hexamethonium (5 × 10-5 g/ml.) reduced vagal relaxation to 11-30% according to the stimulation rate. The residual response was maintained in the presence of 5-hydroxytryptamine tachyphylaxis. 5. Many muscle cells were observed to be under the influence of both vagus and sympathetic nerves: the effect of sympathetic stimulation was always inhibitory in nature, but high stimulation rates were required. The effect of vagal stimulation was both excitatory and inhibitory even in the absence of atropine: low stimulation rates gave rise either to E.J.P.s (excitatory junctional potentials), often followed by spikes, or to I.J.P.s (inhibitory junctional potentials). 6. In some spontaneously firing cells the interruption of electrical activity produced by vagal stimulation at 2/sec and sympathetic stimulation at 20/sec was recorded for a long enough time to check the effect of guanethedine (5 × 10-6 g/ml.): the drug selectively blocked sympathetic inhibition. 7. The significance of the inhibitory non-adrenergic transmitter, released by the intramural neurones activated by preganglionic vagal fibres, is discussed. PMID:4398576

  20. 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.

  1. Essential Role for Neutrophils in Pathogenesis and Adaptive Immunity in Chlamydia caviae Ocular Infections ▿

    PubMed Central

    Lacy, H. Marie; Bowlin, Anne K.; Hennings, Leah; Scurlock, Amy M.; Nagarajan, Uma M.; Rank, Roger G.

    2011-01-01

    Trachoma, the world's leading cause of preventable blindness, is produced by chronic ocular infection with Chlamydia trachomatis, an obligate intracellular bacterium. While many studies have focused on immune mechanisms for trachoma during chronic stages of infection, less research has targeted immune mechanisms in primary ocular infections, events that could impact chronic responses. The goal of this study was to investigate the function of neutrophils during primary chlamydial ocular infection by using the guinea pig model of Chlamydia caviae inclusion conjunctivitis. We hypothesized that neutrophils help modulate the adaptive response and promote host tissue damage. To test these hypotheses, guinea pigs with primary C. caviae ocular infections were depleted of neutrophils by using rabbit antineutrophil antiserum, and immune responses and immunopathology were evaluated during the first 7 days of infection. Results showed that neutrophil depletion dramatically decreased ocular pathology, both clinically and histologically. The adaptive response was also altered, with increased C. caviae-specific IgA titers in tears and serum and decreased numbers of CD4+ and CD8+ T cells in infected conjunctivae. Additionally, there were changes in conjunctival chemokines and cytokines, such as increased expression of IgA-promoting interleukin-5 and anti-inflammatory transforming growth factor β, along with decreased expression of T cell-recruiting CCL5 (RANTES). This study, the first to investigate the role of neutrophils in primary chlamydial ocular infection, indicates a previously unappreciated role for neutrophils in modulating the adaptive response and suggests a prominent role for neutrophils in chlamydia-associated ocular pathology. PMID:21402767

  2. Essential role for neutrophils in pathogenesis and adaptive immunity in Chlamydia caviae ocular infections.

    PubMed

    Lacy, H Marie; Bowlin, Anne K; Hennings, Leah; Scurlock, Amy M; Nagarajan, Uma M; Rank, Roger G

    2011-05-01

    Trachoma, the world's leading cause of preventable blindness, is produced by chronic ocular infection with Chlamydia trachomatis, an obligate intracellular bacterium. While many studies have focused on immune mechanisms for trachoma during chronic stages of infection, less research has targeted immune mechanisms in primary ocular infections, events that could impact chronic responses. The goal of this study was to investigate the function of neutrophils during primary chlamydial ocular infection by using the guinea pig model of Chlamydia caviae inclusion conjunctivitis. We hypothesized that neutrophils help modulate the adaptive response and promote host tissue damage. To test these hypotheses, guinea pigs with primary C. caviae ocular infections were depleted of neutrophils by using rabbit antineutrophil antiserum, and immune responses and immunopathology were evaluated during the first 7 days of infection. Results showed that neutrophil depletion dramatically decreased ocular pathology, both clinically and histologically. The adaptive response was also altered, with increased C. caviae-specific IgA titers in tears and serum and decreased numbers of CD4(+) and CD8(+) T cells in infected conjunctivae. Additionally, there were changes in conjunctival chemokines and cytokines, such as increased expression of IgA-promoting interleukin-5 and anti-inflammatory transforming growth factor β, along with decreased expression of T cell-recruiting CCL5 (RANTES). This study, the first to investigate the role of neutrophils in primary chlamydial ocular infection, indicates a previously unappreciated role for neutrophils in modulating the adaptive response and suggests a prominent role for neutrophils in chlamydia-associated ocular pathology. PMID:21402767

  3. Stimulation of anti-tumour immunity in guinea-pigs by methanol extraction residue of BCG.

    PubMed Central

    Wainberg, M. A.; Deutsch, V.; Weiss, D. W.

    1976-01-01

    The immunoprophylactic effects of the methanol extraction residue (MER) of BCG were investigated in Strain 2 guinea-pigs injected with cells of the transplantable, diethylnitrosamine-induced, Line 10 hepatocarcinoma. Pretreatment with MER at times ranging from 18 to 182 days prior to tumour implantation protected approximately 40% of guinea-pigs from progressive neoplastic disease. In addition, MER-treated animals developed specific cell-mediated anti-tumour immunity both more rapidly and at higher levels than did non-MER-treated tumour-bearing controls. It was not possible, however, to prognosticate from the results of such laboratory studies to the outcome of immunoprophylaxis. PMID:187207

  4. 5'-Adenosine monophosphate and adenosine metabolism, and adenosine responses in mouse, rat and guinea pig heart.

    PubMed

    Headrick, J P; Peart, J; Hack, B; Garnham, B; Matherne, G P

    2001-11-01

    We examined myocardial 5'-adenosine monophosphate (5'-AMP) catabolism, adenosine salvage and adenosine responses in perfused guinea pig, rat and mouse heart. MVO(2) increased from 71+/-8 microl O(2)/min per g in guinea pig to 138+/-17 and 221+/-15 microl O(2)/min per g in rat and mouse. VO(2)/beat was 0.42+/-0.03, 0.50+/-0.03 and 0.55+/-0.04 microl O(2)/g in guinea pig, rat and mouse, respectively. Resting and peak coronary flows were highest in mouse vs. rat and guinea pig, and peak ventricular pressures and Ca(2+) sensitivity declined as heart mass increased. Net myocardial 5'-AMP dephosphorylation increased significantly as mass declined (3.8+/-0.5, 9.0+/-1.4 and 11.0+/-1.6 nmol/min per g in guinea pig, rat and mouse, respectively). Despite increased 5'-AMP catabolism, coronary venous [adenosine] was similar in guinea pig, rat and mouse (45+/-8, 69+/-10 and 57+/-14 nM, respectively). Comparable venous [adenosine] was achieved by increased salvage vs. deamination: 64%, 41% and 39% of adenosine formed was rephosphorylated while 23%, 46%, and 50% was deaminated in mouse, rat and guinea pig, respectively. Moreover, only 35-45% of inosine and its catabolites derive from 5'-AMP (vs. IMP) dephosphorylation in all species. Although post-ischemic purine loss was low in mouse (due to these adaptations), functional tolerance to ischemia decreased with heart mass. Cardiovascular sensitivity to adenosine also differed between species, with A(1) receptor sensitivity being greatest in mouse while A(2) sensitivity was greatest in guinea pig. In summary: (i) cardiac 5'-AMP dephosphorylation, VO(2), contractility and Ca(2+) sensitivity all increase as heart mass falls; (ii) adaptations in adenosine salvage vs. deamination limit purine loss and yield similar adenosine levels across species; (iii) ischemic tolerance declines with heart mass; and (iv) cardiovascular sensitivity to adenosine varies, with increasing A(2) sensitivity relative to A(1) sensitivity in larger hearts.

  5. Limited survey of genital infection by guinea pig inclusion conjunctivitis agent.

    PubMed

    Reed, C; Campbell, L H; Soave, O A

    1977-09-01

    Cervical or urethral scrapings were collected from 245 guinea pigs that had clinical signs of guinea pig inclusion conjunctivitis (GPIC) or were parents of newborn young having clinical signs of GPIC. Giemsa-stained smears were examined for cytoplasmic inclusion bodies, and samples were passaged in 6-day-old embryonating eggs. Complement-fixation tests were performed on 44 samples passaged through eggs in an effort to detect the presence of GPIC antigen. Unequivocal evidence of chlamydial infection of the genital tract was not found.

  6. Biolistic-mediated gene expression in guinea pigs and cattle tissue in vivo.

    PubMed

    Rech, E L; De-Bem, A R; Aragão, F J

    1996-10-01

    Foreign genes were introduced and expressed in vivo in guinea pigs and cattle utilizing a new hand-held device based on high-pressure helium gas to accelerate DNA-coated microparticles. Guinea pigs were used to evaluate the physical parameters to introduce and express the exogenous DNA. The best conditions were applied to conduct bombardments in cattle. The results showed a high frequency of gene expression in all the bombarded cattle. This procedure could be used to study the immune responses in cattle and in a wide variety of animals through genetic immunization. PMID:9181095

  7. 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.

  8. The relationship between contraction and intracellular sodium in rat and guinea-pig ventricular myocytes.

    PubMed Central

    Harrison, S M; McCall, E; Boyett, M R

    1992-01-01

    1. The contraction, measured optically, and the intracellular Na+ activity (aNai), measured with the Na(+)-sensitive fluorescent dye SBFI, have been recorded simultaneously in rat and guinea-pig ventricular myocytes. 2. In rat and guinea-pig ventricular myocytes at rest, aNai was 7.8 +/- 0.3 mM (n = 4) and 5.1 +/- 0.3 mM (n = 16), respectively. 3. When both rat and guinea-pig ventricular myocytes were stimulated at 1 Hz after a rest there was usually a gradual increase in twitch shortening (referred to as a 'staircase') over several minutes accompanied by an increase in aNai over a similar time course. Twitch shortening increased by 21 +/- 3% (n = 6) and 20 +/- 4% (n = 16) (of steady-state twitch shortening during 1 Hz stimulation) per millimolar rise in aNai in rat and guinea-pig ventricular myocytes, respectively. 4. When rat and guinea-pig ventricular myocytes were exposed to strophanthidin to block the Na(+)-K+ pump, there were increases in twitch shortening and aNai over similar time courses. Twitch shortening increased by 24 +/- 4% (n = 5) and 20 +/- 3% (n = 10) (of control twitch shortening) per millimolar rise in aNai in rat and guinea-pig ventricular myocytes respectively. 5. The inotropic effect of cardiac glycosides, such as strophanthidin, is widely regarded to be principally the result of the rise in aNai. The similarity of the relation between twitch shortening and aNai during the staircase and on application of strophanthidin suggests that the progressive increase in the strength of contraction during the staircase was also linked to the rise in aNai. 6. In guinea-pig, but not rat, ventricular myocytes there was hysteresis in the relation between twitch shortening and aNai on application and wash-off of strophanthidin. This indicates that strophanthidin has another inotropic action in guinea-pig ventricular myocytes. 7. A computer model of excitation-contraction coupling has been developed to simulate the staircase and the action of cardiac glycoside

  9. In vitro metabolism of cannabinol in rat, mouse, rabbit, guinea pig, hamster, gerbil and cat.

    PubMed

    Brown, N K; Harvey, D J

    1990-01-01

    Metabolism of cannabinol (CBN) was studied in hepatic microsomal incubates from mouse, rat, rabbit, guinea pig, cat, hamster and gerbil. Metabolites were extracted with ethyl acetate, concentrated by chromatography on Sephadex LH-20 and identified by GC/MS as TMS derivatives. Six monohydroxy metabolites were identified. These had hydroxy groups at C-11 and at all positions of the pentyl side-chain. Metabolism varied considerably between the species. 11-Hydroxylation was the most prominent route in the majority of species, but in the hamster and cat the major metabolic pathway was 4'-hydroxylation. Metabolites hydroxylated in the pentyl chain were generally more abundant in guinea pig, hamster and cat. PMID:2253656

  10. 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

  11. Ambient temperature and pregnancy influence cortisol levels in female guinea pigs and entail long-term effects on the stress response of their offspring.

    PubMed

    Michel, C L; Chastel, O; Bonnet, X

    2011-05-01

    Mammals generally respond to the important metabolic requirements imposed by thermoregulation and pregnancy by increasing plasma concentrations of glucocorticoid that promote the mobilization of body reserves and enhance energy use by tissues. This study examined the impact of distinct ambient temperatures and reproductive status on cortisol plasma levels in female guinea pigs (Cavia aperea f. porcellus). We also examined cortisol profiles of their offspring. Forty adult females were placed in individual boxes, 20 were exposed to a neutral thermal regime (mean ambient temperature 22.1 ± 1.5 °C) and 20 were maintained under a cool thermal regime (15.1 ± 1.5 °C). Within each treatment, 12 females were pregnant and 8 were non-pregnant. Pregnancy generated a marked elevation of baseline cortisol. Ambient temperature also affected cortisol concentrations. Compared to the pregnant females from the neutral thermal regime, pregnant females maintained under cool conditions exhibited lower baseline levels of cortisol, were less active, but they displayed a greater stress response (i.e. rapid increase of plasma cortisol) following handling. Thermal treatment did not influence reproductive output, reproductive effort, or offspring characteristics. This suggests that pregnant female guinea pigs cope with cool (but not extreme) thermal conditions by reducing activity and baseline cortisol levels, possibly to save energy via an adaptive response. Interestingly, the greater amplitude of the stress response of the cool regime females was also observed in their offspring 2 months after parturition, suggesting that hormonal ambience experienced by the individuals in utero shaped their stress response long after birth.

  12. Ascorbic acid suppresses endotoxemia and NF-κB signaling cascade in alcoholic liver fibrosis in guinea pigs: a mechanistic approach.

    PubMed

    Abhilash, P A; Harikrishnan, R; Indira, M

    2014-01-15

    Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-κB activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4g/kg b.wt for 90days. After 90days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250mg/kg b.wt) and AA (250mg/kg b.wt) supplemented groups and maintained for 30days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKKβ and the protein expressions of phospho-IκBα, NF-κB, TNF-α, TGF-β1 and IL-6 were also altered in ethanol group. The expressions of fibrosis markers α-SMA, α1 (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-κB activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKKβ, which decreased the activation of NF-κB and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. PMID:24239723

  13. 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.

  14. Electron microscopic observations concerning the in vivo uptake and release of the agent of guinea-pig inclusion conjunctivitis (Chlamydia psittaci) in guinea-pig exocervix.

    PubMed

    Soloff, B L; Rank, R G; Barron, A L

    1985-07-01

    This report details electron-microscopical observations concerning C. psittaci infection in vivo. The model employed was that of the guinea-pig infected at the exocervical region with the agent of guinea-pig inclusion conjunctivitis (GPIC). Our observations indicate that chlamydial particles gain access to their target cells by the mechanism of endocytosis. Single GPIC elementary bodies were seen to be positioned within individual endosomes. The observations reported here provide evidence that chlamydial particles that had undergone their developmental cycle within the exocervical epithelial cells may leave the epithelium in 2 ways; within entire infected cells that had been shed into the lumen of the cervix and by means of the liberation of chlamydial particles from disrupted cells. The mechanism of cell disruption and shedding is thought to involve the large number of PMNs observed to be present within the enlarged intercellular spaces of the infected epithelium.

  15. 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.

  16. Immunization with extracellular proteins of Mycobacterium tuberculosis induces cell-mediated immune responses and substantial protective immunity in a guinea pig model of pulmonary tuberculosis.

    PubMed Central

    Pal, P G; Horwitz, M A

    1992-01-01

    We have studied the capacity of a selected fraction of Mycobacterium tuberculosis extracellular proteins (EP) released into broth culture by mid-logarithmic-growth-phase organisms to induce cell-mediated immune responses and protective immunity in a guinea pig model of pulmonary tuberculosis. Guinea pigs infected with M. tuberculosis by aerosol but not uninfected control guinea pigs exhibit strong cell-mediated immune responses to EP, manifest by dose-dependent cutaneous delayed-type hypersensitivity and splenic lymphocyte proliferation. Guinea pigs immunized subcutaneously with EP but not sham-immunized control guinea pigs also develop strong cell-mediated immune responses to EP, manifest by dose-dependent cutaneous delayed-type hypersensitivity and splenic lymphocyte proliferation. EP is nonlethal and nontoxic to guinea pigs upon subcutaneous immunization. Guinea pigs immunized with EP and then challenged with aerosolized M. tuberculosis exhibit protective immunity. In five independent experiments, EP-immunized guinea pigs were consistently protected against clinical illness, including weight loss. Compared with EP-immunized guinea pigs, sham-immunized control guinea pigs lost 12.9 +/- 2.0% (mean +/- SE) of their total weight. EP-immunized guinea pigs also had a 10-fold reduction in viable M. tuberculosis bacilli in their lungs and spleens (P = 0.004 and 0.001, respectively) compared with sham-immunized control animals. In the two experiments in which some guinea pigs died after aerosol challenge, EP-immunized animals were protected from death. Whereas all 12 (100%) EP-immunized guinea pigs survived challenge with aerosolized M. tuberculosis, only 6 of 12 (50%) sham-immunized control guinea pigs survived challenge (P = 0.007, Fisher exact test). This study demonstrates that actively growing M. tuberculosis cells release immunoprotective molecules extracellularly, that a subunit vaccine against tuberculosis is feasible, and that extracellular molecules of M

  17. Allergy to guinea pigs: I. Allergenic activities of extracts derived from the pelt, saliva, urine and other sources.

    PubMed

    Walls, A F; Newman Taylor, A J; Longbottom, J L

    1985-05-01

    Guinea pig-sensitive patients with asthma and rhinitis were skin test positive to extracts of several materials derived from guinea pigs. A radioallergosorbent test (RAST) was developed to measure serum IgE specific for the dander, urine, saliva and also for dust from the air-vent filters of a room housing guinea pigs. A strong correlation was found between positive skin test reactions, and raised serum IgE to these extracts. Furthermore, the relative allergenic potency of extracts was similar when determined by skin-prick testing and by inhibition of the RAST to guinea pig dust. Non-guinea pig-derived extracts such as the hay, sawdust and diet had negligible activity in skin testing and RAST inhibition; and preparations of Dermatophagoides pteronyssinus, house dust and rat dust did not inhibit the RAST for guinea pig room dust. The guinea pig dust, dander, fur, urine and saliva were the more potent extracts; while whole pelt, faeces and serum were considerably less active. Extracts from different sexes were not appreciably different in potency. The results of skin testing, RAST and RAST inhibition suggest cross-allergenicity between the various extracts. Although material shed from the pelt may have been derived from saliva, or even urine, allergenic activities of urinary and salivary preparations were found to be less than those of the dander, fur or dust. This suggests that allergens have become concentrated on the pelt. PMID:4006174

  18. Recognition of Modified Conditioning Sounds by Competitively Trained Guinea Pigs.

    PubMed

    Ojima, Hisayuki; Horikawa, Junsei

    2015-01-01

    The guinea pig (GP) is an often-used species in hearing research. However, behavioral studies are rare, especially in the context of sound recognition, because of difficulties in training these animals. We examined sound recognition in a social competitive setting in order to examine whether this setting could be used as an easy model. Two starved GPs were placed in the same training arena and compelled to compete for food after hearing a conditioning sound (CS), which was a repeat of almost identical sound segments. Through a 2-week intensive training, animals were trained to demonstrate a set of distinct behaviors solely to the CS. Then, each of them was subjected to generalization tests for recognition of sounds that had been modified from the CS in spectral, fine temporal and tempo (i.e., intersegment interval, ISI) dimensions. Results showed that they discriminated between the CS and band-rejected test sounds but had no preference for a particular frequency range for the recognition. In contrast, sounds modified in the fine temporal domain were largely perceived to be in the same category as the CS, except for the test sound generated by fully reversing the CS in time. Animals also discriminated sounds played at different tempos. Test sounds with ISIs shorter than that of the multi-segment CS were discriminated from the CS, while test sounds with ISIs longer than that of the CS segments were not. For the shorter ISIs, most animals initiated apparently positive food-access behavior as they did in response to the CS, but discontinued it during the sound-on period probably because of later recognition of tempo. Interestingly, the population range and mean of the delay time before animals initiated the food-access behavior were very similar among different ISI test sounds. This study, for the first time, demonstrates a wide aspect of sound discrimination abilities of the GP and will provide a way to examine tempo perception mechanisms using this animal species

  19. Recognition of Modified Conditioning Sounds by Competitively Trained Guinea Pigs

    PubMed Central

    Ojima, Hisayuki; Horikawa, Junsei

    2016-01-01

    The guinea pig (GP) is an often-used species in hearing research. However, behavioral studies are rare, especially in the context of sound recognition, because of difficulties in training these animals. We examined sound recognition in a social competitive setting in order to examine whether this setting could be used as an easy model. Two starved GPs were placed in the same training arena and compelled to compete for food after hearing a conditioning sound (CS), which was a repeat of almost identical sound segments. Through a 2-week intensive training, animals were trained to demonstrate a set of distinct behaviors solely to the CS. Then, each of them was subjected to generalization tests for recognition of sounds that had been modified from the CS in spectral, fine temporal and tempo (i.e., intersegment interval, ISI) dimensions. Results showed that they discriminated between the CS and band-rejected test sounds but had no preference for a particular frequency range for the recognition. In contrast, sounds modified in the fine temporal domain were largely perceived to be in the same category as the CS, except for the test sound generated by fully reversing the CS in time. Animals also discriminated sounds played at different tempos. Test sounds with ISIs shorter than that of the multi-segment CS were discriminated from the CS, while test sounds with ISIs longer than that of the CS segments were not. For the shorter ISIs, most animals initiated apparently positive food-access behavior as they did in response to the CS, but discontinued it during the sound-on period probably because of later recognition of tempo. Interestingly, the population range and mean of the delay time before animals initiated the food-access behavior were very similar among different ISI test sounds. This study, for the first time, demonstrates a wide aspect of sound discrimination abilities of the GP and will provide a way to examine tempo perception mechanisms using this animal species

  20. Papular Dermatitis Induced in Guinea Pig by Biting Midge Culicoides Sonorensis (Diptera: Ceratopogonidaie)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 h...

  1. T-lymphocyte responses in guinea pigs vaccinated with foot-and-mouth disease virus.

    PubMed

    Bartels, T; Schäfer, H; Liebermann, H; Burger, R; Beyer, J

    1994-03-01

    The guinea pig provides an alternative experimental model for analysis of the immune response against foot-and-mouth disease virus (FMDV). The cellular immune response against FMDV in this experimental animal is unknown and was analyzed by in vivo and in vitro studies. In guinea pigs immunized with an FMDV A5 vaccine, a marked change in T-lymphocyte count appeared. For analyzing which functional T-cell compartment was affected, immunofluorescence studies, using monoclonal antibodies directed against differentiation antigens on guinea pig lymphoid cells, were performed. The proliferating T-cells were predominantly CD4-positive and, therefore, helper cells. T-cells from these animals were re-stimulated in vitro with homologous inactivated virus. The antigen-specific proliferative response of the T-cells in vitro was measured using the thymidine incorporation assay. A proliferative response to FMDV was observed that depended on the dose of the antigen. High concentration of virus had an inhibitory effect on T-cell proliferation. These data indicate that the guinea pig is a useful model for analysis of T-cell mediated mechanisms in the pathogenesis and immunity of foot-and-mouth disease. PMID:7909182

  2. Pathogenesis of endometritis and salpingitis in a guinea pig model of chlamydial genital infection.

    PubMed Central

    Rank, R. G.; Sanders, M. M.

    1992-01-01

    The development of tubal obstruction and subsequent infertility is a major sequelum of upper genital tract infection with Chlamydia trachomatis; however, little is known about the pathogenesis of the infection. In this investigation, the authors present a detailed study of the progression of ascending chlamydial infection in female guinea pigs resulting from intravaginal inoculation of the Chlamydia psittaci agent of guinea pig inclusion conjunctivitis (GPIC). Isolation of chlamydiae from different tissues of the genital tract revealed definitive evidence for ascending infection that was not dose-related. By 7 days after infection, GPIC was isolated from the endometrium and oviducts of 78% of the animals. Pathologic changes analogous to those seen in human chlamydial disease, including polymorphonuclear, mononuclear, and plasma cell infiltration, were seen in the endometrium and oviducts, although not all isolation positive animals developed overt tubal disease. Long-term fibrosis, often in combination with hydrosalpinx, was noted in the mesosalpingeal tissue in 20% of the animals. Thus, the guinea pig:GPIC system represents a model for ascending chlamydial infection resulting from vaginal inoculation of normal guinea pigs that closely approximates the disease as seen in humans and can be used to study the pathogenesis of chlamydial genital infection. Images Figure 4 Figure 7 Figure 8 Figure 9 Figure 10 PMID:1562052

  3. Effects of polylactic acid film on middle ear mucosa and cochlear function in Guinea pigs.

    PubMed

    Ensari, Nuray; Tutar, Hakan; Ekinci, Ozgur; Ugur, Mehmet Birol; Bayazıt, Yıldırım A; Gokdogan, Cagil; Goksu, Nebil

    2015-05-01

    Our aim was to assess the effects of polylactic acid (PLA) on middle ear mucosa and cochlea, to be used as a film barrier for postoperative adhesion prevention in the middle ear. Twenty-one albino Guinea pigs were included in the study. A window was opened on both tympanic bulla and on one side PLA material was placed in the middle ear and on the other side only fenestration was performed and used as a control. All Guinea pigs underwent evaluation of tympanic membranes microscopically; functional hearing was analyzed by auditory brainstem responses preoperatively, in the first and the sixth month. All Guinea pigs were killed on the sixth month for histopathologic evaluation of their temporal bones. There was no statistical difference between both groups regarding hearing thresholds, interpeak wave latencies preoperatively and on first and the sixth months postoperatively. Histopathological evaluation revealed no specific changes. There was a mild local inflammation both in the PLA implanted and control ears. PLA film barrier most likely has no toxic effects on Guinea pig middle ear and does not show any ototoxic side effects.

  4. 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

  5. Immunization of mice and guinea-pigs against Salmonella dublin infection with live and inactivated vaccine.

    PubMed

    Cameron, C M; Fuls, W J

    1975-06-01

    The immunogenicity of a number of avirulent rough Salmonella dublin mutants was compared in mice and guinea-pigs. Live vaccine prepared from Strain HB 1/17 at doses of 5 X 10(7) per mouse usually gave an immunity of between 70 and 80% but in certain experiments the results were more variable and always poorer. This strain gave a cross protection of 28,5% to S. typhimurium in mice. In guinea-pigs it evoked an average protection of approximately 46% to homologous challenge and approximately 26% to challenge with S. tryphimurium. Strain 5765 protected up to 80% of mice against S. dublin infection and was generally superior to Strain HB 1/17 in this respect. It was, however, less effective in protecting mice against S. tryphimurium (20%). In guinea-pigs it was also less effective than Strain HB 1/17, giving 34% protection against homologous and 20% against heterologous challenge. Other strains also produced immunity in mice but they were not studied in detail. Formalin-inactivated alum-precipitated vaccine prepared from avirulent smooth strain and containing 0,5% packed cells proved to be extremely effective in protecting mice against S. dublin infection. It produced an average immunity of 75% and was often 100% effective. It also protected 60% of mice against challenge with S. tryphimurium. In guinea-pigs it was, however, totally ineffective against challenge with both S. dublin and S. tryphimurium.

  6. Pathogenesis of endometritis and salpingitis in a guinea pig model of chlamydial genital infection.

    PubMed

    Rank, R G; Sanders, M M

    1992-04-01

    The development of tubal obstruction and subsequent infertility is a major sequelum of upper genital tract infection with Chlamydia trachomatis; however, little is known about the pathogenesis of the infection. In this investigation, the authors present a detailed study of the progression of ascending chlamydial infection in female guinea pigs resulting from intravaginal inoculation of the Chlamydia psittaci agent of guinea pig inclusion conjunctivitis (GPIC). Isolation of chlamydiae from different tissues of the genital tract revealed definitive evidence for ascending infection that was not dose-related. By 7 days after infection, GPIC was isolated from the endometrium and oviducts of 78% of the animals. Pathologic changes analogous to those seen in human chlamydial disease, including polymorphonuclear, mononuclear, and plasma cell infiltration, were seen in the endometrium and oviducts, although not all isolation positive animals developed overt tubal disease. Long-term fibrosis, often in combination with hydrosalpinx, was noted in the mesosalpingeal tissue in 20% of the animals. Thus, the guinea pig:GPIC system represents a model for ascending chlamydial infection resulting from vaginal inoculation of normal guinea pigs that closely approximates the disease as seen in humans and can be used to study the pathogenesis of chlamydial genital infection.

  7. Utility of Oral Swab Sampling for Ebola Virus Detection in Guinea Pig Model.

    PubMed

    Spengler, Jessica R; Chakrabarti, Ayan K; Coleman-McCray, JoAnn D; Martin, Brock E; Nichol, Stuart T; Spiropoulou, Christina F; Bird, Brian H

    2015-10-01

    To determine the utility of oral swabs for diagnosing infection with Ebola virus, we used a guinea pig model and obtained daily antemortem and postmortem swab samples. According to quantitative reverse transcription PCR analysis, the diagnostic value was poor for antemortem swab samples but excellent for postmortem samples.

  8. Oral therapy using nanoparticle-encapsulated antituberculosis drugs in guinea pigs infected with Mycobacterium tuberculosis.

    PubMed

    Johnson, Christine M; Pandey, Rajesh; Sharma, Sadhna; Khuller, G K; Basaraba, Randall J; Orme, Ian M; Lenaerts, Anne J

    2005-10-01

    We evaluated the efficacy of nanoparticle-encapsulated antituberculosis drugs administered every 10 days versus that of daily nonencapsulated drugs against Mycobacterium tuberculosis aerosol infection in guinea pigs. Both treatments significantly reduced the bacterial count and lung histopathology, suggesting that the nanoparticle drug delivery system has potential in intermitted treatment of tuberculosis.

  9. Calcium antagonistic activity of Bacopa monniera in guinea-pig trachea

    PubMed Central

    Channa, Shabana; Dar, Ahsana

    2012-01-01

    Objective: To demonstrate the calcium antagonistic property of ethanol extract of Bacopa monniera in guinea-pig trachea. Materials and Methods: The dose response curves of CaCl2 (1 × 10-5 to 1 × 10-1 M) were constructed in the absence and presence of ethanol extract of Bacopa monniera (100, 500 and 700 μg/ml) or nifedipine (1 × 10-6 M) in guinea-pig trachea in calcium free high K+-MOPS-PSS (3-(N-morpholino)-propanesulphonic acid physiological salt solution). The data was analyzed by ANOVA followed by least significant difference test or by Student's ‘t’ test for unequal variance when appropriate. A probability of at least P < 0.05 was considered statistically significant. Results: The plant extract (500 and 700 μg/ml) significantly (P < 0.05) depressed and shifted the calcium concentration-response curves (1 × 10-3- 1 × 10-1 M) to rightward similar to that of nifedipine. Conclusions: Bacopa monniera extract exhibited calcium channel blocking activity in guinea-pig tracheal smooth muscles that may rationalize its relaxant action on guinea-pig trachea and its traditional use in respiratory disorders. PMID:23087517

  10. The influence of starvation upon hepatic drug metabolism in rats, mice, and guinea pigs.

    NASA Technical Reports Server (NTRS)

    Furner, R. L.; Feller, D. D.

    1971-01-01

    Male rats, mice, and guinea pigs were starved for 1, 2, or 3 days, and the metabolism of ethylmorphine, p-nitroanisole, and aniline was studied. Results suggest that the oxidative enzyme systems studied are not interdependent, and the pathways studied appear to be species dependent.

  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. 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 ...

  13. Sensitization studies in the guinea pig with the active ingredients of Euxyl K 400.

    PubMed

    Bruze, M; Gruvberger, B; Agrup, G

    1988-01-01

    The preservative Euxyl K 400 consists of the 2 active ingredients, 2-phenoxyethanol and 1,2-dibromo-2,4-dicyanobutane. Sensitization studies with the guinea pig maximization test were performed with these substances, but no sensitizing capacity was demonstrated in the case of either compound.

  14. Primary structure and functional expression of a guinea pig kappa opioid (dynorphin) receptor.

    PubMed Central

    Xie, G X; Meng, F; Mansour, A; Thompson, R C; Hoversten, M T; Goldstein, A; Watson, S J; Akil, H

    1994-01-01

    A full-length cDNA encoding the guinea pig kappa opioid (dynorphin) receptor has been isolated. The deduced protein contains 380 aa and seven hydrophobic alpha-helices characteristic of the G protein-coupled receptors. This receptor is 90% identical to the mouse and rat kappa receptors, with the greatest level of divergence in the N-terminal region. When expressed in COS-7 cells, the receptor displays high affinity and stereospecificity toward dynorphin peptides and other kappa-selective opioid ligands such as U50, 488. It does not bind the mu- and delta-selective opioid ligands. The expressed receptor is functionally coupled to G protein(s) to inhibit adenylyl cyclase and Ca2+ channels. The guinea pig kappa receptor mRNA is expressed in many brain areas, including the cerebellum, a pattern that agrees well with autoradiographic maps of classical guinea pig kappa binding sites. Species differences in the pharmacology and mRNA distribution between the cloned guinea pig and rat kappa receptors may be worthy of further examination. Images PMID:8170987

  15. THE INFLUENCE OF THE "DIAPLYTE" ANTIGEN OF DREYER ON TUBERCULOSIS OF THE GUINEA PIG.

    PubMed

    Bronfenbrenner, J J; Straub, E L

    1925-01-31

    We have prepared "diaplyte" antigen according to Dreyer's procedure and have studied its therapeutic and prophylactic value in experimental tuberculosis of guinea pigs. In our hands it has failed to yield beneficial effects. The animals treated with the antigen tended in general to develop lesions more quickly and to die earlier than the controls.

  16. Occurrence of parasympathetic vasodilator fibers in the lower lip of the guinea-pig.

    PubMed

    Watanabe, H; Ishii, H; Niioka, T; Yamamuro, M; Izumi, H

    2008-03-01

    The present study was designed to examine whether there are parasympathetic vasodilator fibers in the lower lip of the guinea-pig. Electrical stimulation of the central cut end of the lingual nerve of guinea-pigs evoked intensity- and frequency-dependent decreases in lower lip blood flow and systemic arterial blood pressure (SABP). Pretreatment with guanethidine, a postganglionic sympathetic nerve blocker and antihypertensive drug (30 mg kg(-1), s.c., 24 h prior to experiments), reduced the magnitude of the decrease in SABP while the intensity- and frequency-dependent increases of the lip blood flow occurred by the lingual nerve stimulation only on the side ipsilateral to stimulation. Increases in the lip blood flow evoked by lingual nerve stimulation in guanethidine pretreated guinea-pigs were reduced by hexamethonium (an autonomic ganglion cholinergic blocker) in a dose-dependent manner. When fluoro-gold (a retrograde neural tracer) was injected into the lower lip, labeled neurons were observed in the ipsilateral otic ganglion. The present study indicates the presence of parasympathetic vasodilator fibers originating from the otic parasympathetic ganglion in the guinea-pig lower lip, similar to those reported previously in rats, cats, rabbits and humans. PMID:18030480

  17. [The effection of obstructing OCB with strychnine on the guinea pig's DPOAE].

    PubMed

    Li, K; Wang, Z; Ni, D

    1998-08-01

    The strychnine was used to obstruct the oliver cochlear bundle (OCB) in order to explore the effect of the efferent system on distortion product otoacoustic emission (DPOAE) of guinea pig. The result showed that the DPOAE were not changed after strychnine were administrated. It is concluded that the efferent pulses of the CNS does not affect on DPOAE in silent circumstance. PMID:11263161

  18. Adrenergic lipolysis in guinea pig is not a beta 3-adrenergic response: comparison with human adipocytes.

    PubMed

    Carpéné, C; Castan, I; Collon, P; Galitzky, J; Moratinos, J; Lafontan, M

    1994-03-01

    beta 3-Adrenoceptor agonists are potent lipolytic activators in rats, but they are only weak stimulators in human adipocytes, indicating interspecies differences in the adrenergic regulation of lipid mobilization. Like human but not rat adipocytes, guinea pig fat cells were poorly responsive to the beta 3-agonists BRL-37344, CGP-12177, SR-58611, and ICI-215001, acid metabolite of ICI-D7114. In guinea pigs, the beta 1-agonist dobutamine was more lipolytic than the beta 2-agonist procaterol. Anatomic location of fat deposits was without major influence on the beta-adrenergic responsiveness. Weak responses to beta 3-agonists were found whatever the sex or the age (from 2 days to 16 mo) of the animals. Even in the interscapular brown adipose tissue, which is well known in rats for its beta 3-adrenergic responsiveness, a blunted response to BRL-37344 was observed. The alpha 2-adrenergic antilipolytic effect and receptor number were smaller in guinea pig than in human adipocytes, but the beta-adrenergic receptor number was similar in the two species. Thus guinea pig adipocytes resemble human fat cells when their weak beta 3-adrenergic responsiveness is considered. PMID:7909205

  19. Skin sensitization, false positives and false negatives: experience with guinea pig assays.

    PubMed

    Basketter, David A; Kimber, Ian

    2010-07-01

    The advent of the local lymph node assay (LLNA), and efforts to develop in vitro alternatives for the identification of skin sensitizing chemicals has focused attention on the issue of false positive and false negative results. In essence, the question becomes 'what is the gold standard?' In this context, attention has focused primarily on the LLNA as this is now the preferred assay for skin sensitization testing. However, for many years prior to introduction of the LLNA, the guinea pig maximization test and the occluded patch test of Buehler were the methods of choice. In order to encourage a more informed dialogue about the relative performance, accuracy and applicability of the LLNA and guinea pig tests, we have here considered the extent to which guinea pig methods were themselves subject to false positives and negative results. We describe and discuss here well-characterized examples of instances where both false negatives (including abietic acid and eugenol) or false positives (including vanillin and sulfanilic acid) have been recorded in guinea pig tests. These and other examples are discussed with particular reference to the fabrication of a gold standard dataset that is required for the validation of in vitro alternatives.

  20. 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.

  1. The sensitizing potential of primary amyl acetate in the guinea pig.

    PubMed

    Ballantyne, B; Tyler, T R; Auletta, C S

    1986-06-01

    Primary amyl acetate is a liquid mixture of the isomeric forms of pentyl acetate, which is used as a volatile organic solvent. Because of the possibility for skin contact, primary amyl acetate was investigated for its potential to cause allergic contact dermatitis. Using a guinea pig maximization procedure, primary amyl acetate was found to be a possible marginal skin sensitizer. PMID:3727350

  2. Utility of Oral Swab Sampling for Ebola Virus Detection in Guinea Pig Model.

    PubMed

    Spengler, Jessica R; Chakrabarti, Ayan K; Coleman-McCray, JoAnn D; Martin, Brock E; Nichol, Stuart T; Spiropoulou, Christina F; Bird, Brian H

    2015-10-01

    To determine the utility of oral swabs for diagnosing infection with Ebola virus, we used a guinea pig model and obtained daily antemortem and postmortem swab samples. According to quantitative reverse transcription PCR analysis, the diagnostic value was poor for antemortem swab samples but excellent for postmortem samples. PMID:26401603

  3. 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.

  4. Protein A suppresses immune responses during Staphylococcus aureus bloodstream infection in guinea pigs

    DOE PAGESBeta

    Kim, Hwan Keun; Falugi, Fabiana; Thomer, Lena; Missiakas, Dominique M.; Schneewind, Olaf

    2015-01-06

    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 Bmore » cell responses. Immunization with SpAKKAA, which cannot bind immunoglobulin, elicits neutralizing antibodies that enable guinea pigs to develop protective immunity.« less

  5. Effect of ochratoxin and aflatoxin on serum proteins, complement activity, and antibody production to Brucella abortus in guinea pigs.

    PubMed

    Richard, J L; Thurston, J R; Deyoe, B L; Booth, G D

    1975-01-01

    The effect of ochratoxin alone and in combination with aflatoxin and Brucella abortus antigen on complement activity, serum proteins, and antibody response in guinea pigs was investigated. Ochratoxin did not affect complement activity or antibody response and there was no interaction between ochratoxin and aflatoxin on any of the responses tested. Ochratoxin significantly lowered the level of beta-globulin in serum of guinea pigs. There was no significant interaction between aflatoxin and antigen on lowering of the serum albumin levels of guinea pigs. PMID:45955

  6. The effects of an alpha hydroxy acid (glycolic acid) on hairless guinea pig skin permeability.

    PubMed

    Hood, H L; Kraeling, M E; Robl, M G; Bronaugh, R L

    1999-11-01

    The barrier integrity of hairless guinea pig skin after treatment with an alpha hydroxy acid was assessed through in vivo topical application of an oil-in-water emulsion containing 5 or 10% glycolic acid at pH 3.0. The control was a commercial moisturizing lotion, pH 7.8. A dosing regimen for the glycolic acid formulations that was tolerated by the hairless guinea pigs and significantly decreased stratum corneum turnover time was determined using the dansyl chloride staining technique. Once-daily dosing of hairless guinea pig skin for 3 weeks with the glycolic acid formulations resulted in approximately a 36-39% decrease in stratum corneum turnover time compared with the control lotion. After this treatment, hairless guinea pigs were sacrificed for the in vitro measurement of the percutaneous absorption of [14C]hydroquinone and [14C]musk xylol. No significant differences in the 24-hour absorption of either test compound were found for skin treated with the control lotion or the glycolic acid formulations. There were also no significant differences found in the absorption of [3H]water through skin from the different treatment groups. Although no increase in skin penetration occurred after treatment with the glycolic acid formulations, histology revealed approximately a twofold increase in epidermal thickness. Also the number of nucleated cell layers nearly doubled in skin treated with 5% and 10% glycolic acid compared with the control lotion and untreated skin. These studies demonstrate that substantial changes in the structure of hairless guinea pig epidermis can occur without significant effect on skin permeability of two model compounds.

  7. Assessing recruitment of lung diffusing capacity in exercising guinea pigs with a rebreathing technique

    PubMed Central

    Yilmaz, Cuneyt; Dane, D. Merrill; Hsia, Connie C. W.

    2008-01-01

    Noninvasive techniques for assessing cardiopulmonary function in small animals are limited. We previously developed a rebreathing technique for measuring lung volume, pulmonary blood flow, diffusing capacity for carbon monoxide (DlCO) and its components, membrane diffusing capacity (DmCO) and pulmonary capillary blood volume (Vc), and septal volume, in conscious nonsedated guinea pigs at rest. Now we have extended this technique to study guinea pigs during voluntary treadmill exercise with a sealed respiratory mask attached to a body vest and a test gas mixture containing 0.5% SF6 or Ne, 0.3% CO, and 0.8% C2H2 in 40% or 98% O2. From rest to exercise, O2 uptake increased from 12.7 to 25.5 ml·min−1·kg−1 while pulmonary blood flow increased from 123 to 239 ml/kg. The measured DlCO, DmCO, and Vc increased linearly with respect to pulmonary blood flow as expected from alveolar microvascular recruitment; body mass-specific relationships were consistent with those in healthy human subjects and dogs studied with a similar technique. The results show that 1) cardiopulmonary interactions from rest to exercise can be measured noninvasively in guinea pigs, 2) guinea pigs exhibit patterns of exercise response and alveolar microvascular recruitment similar to those of larger species, and 3) the rebreathing technique is widely applicable to human (∼70 kg), dog (20–30 kg), and guinea pig (1–1.5 kg). In theory, this technique can be extended to even smaller animals provided that species-specific technical hurdles can be overcome. PMID:18483171

  8. Pulmonary effects of inhaled zinc oxide in human subjects, guinea pigs, rats, and rabbits

    SciTech Connect

    Gordon, T.; Chen, L.C.; Fine, J.M.; Schlesinger, R.B.; Su, W.Y.; Kimmel, T.A.; Amdur, M.O. )

    1992-08-01

    Occupational exposure to freshly formed zinc oxide (ZnO) particles (less than 1.0 micron aerodynamic diameter) produces a well-characterized response known as metal fume fever. An 8-hr threshold limit value (TLV) of 5 mg/m3 has been established to prevent adverse health effects because of exposure to ZnO fumes. Because animal toxicity studies have demonstrated pulmonary effects near the current TLV, the present study examined the time course and dose-response of the pulmonary injury produced by inhaled ZnO in guinea pigs, rats, rabbits, and human volunteers. The test animals were exposed to 0, 2.5, or 5.0 mg/m3 ZnO for up to 3 hr and their lungs lavaged. Both the lavage fluid and recovered cells were examined for evidence of inflammation or altered cell function. The lavage fluid from guinea pigs and rats exposed to 5 mg/m3 had significant increases in total cells, lactate dehydrogenase, beta-glucuronidase, and protein content. These changes were greatest 24 hr after exposure. Guinea pig alveolar macrophage function was depressed as evidenced by in vitro phagocytosis of opsonized latex beads. Significant changes in lavage fluid parameters were also observed in guinea pigs and rats exposed to 2.5 mg/m3 ZnO. In contrast, rabbits showed no increase in biochemical or cellular parameters following a 2-hr exposure to 5 mg/m3 ZnO. Differences in total lung burden of ZnO, as determined in additional animals by atomic absorption spectroscopy, appeared to account for the observed differences in species responses. Although the lungs of guinea pigs and rats retained approximately 20% and 12% of the inhaled dose, respectively, rabbits retained only 5%.

  9. Effects of 900 MHz electromagnetic field emitted by cellular phones on electrocardiograms of guinea pigs.

    PubMed

    Meral, I; Tekintangac, Y; Demir, H

    2014-02-01

    This study was carried out to determine the effects of electromagnetic field (EMF) emitted by cellular phones (CPs) on electrocardiograms (ECGs) of guinea pigs. A total of 30 healthy guinea pigs weighing 500-800 g were used. After 1 week of adaptation period, animals were randomly divided into two groups: control group (n = 10) and EMF-exposed group (n = 20). Control guinea pigs were housed in a separate room without exposing them to EMFs of CPs. Animals in second group were exposed to 890-915 MHz EMF (217 Hz of pulse rate, 2 W of maximum peak power and 0.95 wt kg(-1) of specific absorption rate) for 12 h day(-1) (11 h 45 min stand-by and 15 min speaking mode) for 30 days. ECGs of guinea pigs in both the groups were recorded by a direct writing electrocardiograph at the beginning and 10th, 20th and 30th days of the experiment. All ECGs were standardized at 1 mV = 10 mm and with a chart speed of 50 mm sec(-1). Leads I, II, III, lead augmented vector right (aVR), lead augmented vector left (aVL) and lead augmented vector foot (aVF) were recorded. The durations and amplitudes of waves on the trace were measured in lead II. The data were expressed as mean with SEM. It was found that 12 h day(-1) EMF exposure for 30 days did not have any significant effects on ECG findings of guinea pigs. However, this issue needed to be further investigated in a variety of perspectives, such as longer duration of exposure to be able to elucidate the effects of mobile phone-induced EMFs on cardiovascular functions.

  10. Uptake and Accumulation of Oxidized Low-Density Lipoprotein during Mycobacterium tuberculosis Infection in Guinea Pigs

    PubMed Central

    Palanisamy, Gopinath S.; Kirk, Natalie M.; Ackart, David F.; Obregón-Henao, Andrés; Shanley, Crystal A.; Orme, Ian M.; Basaraba, Randall J.

    2012-01-01

    The typical host response to infection of humans and some animals by M. tuberculosis is the accumulation of reactive oxygen species generating inflammatory cells into discrete granulomas, which frequently develop central caseous necrosis. In previous studies we showed that infection of immunologically naïve guinea pigs with M. tuberculosis leads to localized and systemic oxidative stress that results in a significant depletion of serum total antioxidant capacity and the accumulation of malondialdehyde, a bi-product of lipid peroxidation. Here we show that in addition, the generation of excessive reactive oxygen species in vivo resulted in the accumulation of oxidized low density lipoproteins (OxLDL) in pulmonary and extrapulmonary granulomas, serum and lung macrophages collected by bronchoalveolar lavage. Macrophages from immunologically naïve guinea pigs infected with M. tuberculosis also had increased surface expression of the type 1 scavenger receptors CD36 and LOX1, which facilitate the uptake of oxidized host macromolecules including OxLDL. Vaccination of guinea pigs with Bacillus Calmette Guerin (BCG) prior to aerosol challenge reduced the bacterial burden as well as the intracellular accumulation of OxLDL and the expression of macrophage CD36 and LOX1. In vitro loading of guinea pig lung macrophages with OxLDL resulted in enhanced replication of bacilli compared to macrophages loaded with non-oxidized LDL. Overall, this study provides additional evidence of oxidative stress in M. tuberculosis infected guinea pigs and the potential role OxLDL laden macrophages have in supporting intracellular bacilli survival and persistence. PMID:22493658

  11. Sp8 expression in putative neural progenitor cells in guinea pig and human cerebrum.

    PubMed

    Zhang, Xue-Mei; Cai, Yan; Wang, Fang; Wu, Jun; Mo, Lin; Zhang, Feng; Patrylo, Peter R; Pan, Aihua; Ma, Chao; Fu, Jin; Yan, Xiao-Xin

    2016-09-01

    Neural stem/progenitor cells have been characterized at neurogenic sites in adult mammalian brain with various molecular markers. Here it has been demonstrated that Sp8, a transcription factor typically expressed among mature GABAergic interneurons, also labels putative neural precursors in adult guinea pig and human cerebrum. In guinea pigs, Sp8 immunoreactive (Sp8+) cells were localized largely in the superficial layers of the cortex including layer I, as well as the subventricular zone (SVZ) and subgranular zone (SGZ). Sp8+ cells at the SGZ showed little colocalization with mature and immature neuronal markers, but co-expressed neural stem cell markers including Sox2. Some layer I Sp8+ cells also co-expressed Sox2. The amount of Sp8+ cells in the dentate gyrus was maintained 2 weeks after X-ray irradiation, while that of doublecortin (DCX+) cells was greatly reduced. Mild ischemic insult caused a transient increase of Sp8+ cells in the SGZ and layer I, with the subgranular Sp8+ cells exhibited an increased colabeling for the mitotic marker Ki67 and pulse-chased bromodeoxyuridine (BrdU). Sp8+ cells in the dentate gyrus showed an age-related decline in guinea pigs, in parallel with the loss of DCX+ cells in the same region. In adult humans, Sp8+ cells exhibited comparable morphological features as seen in guinea pigs, with those at the SGZ and some in cortical layer I co-expressed Sox2. Together, these results suggested that Sp8 may label putative neural progenitors in guinea pig and human cerebrum, with the labeled cells in the SGZ appeared largely not mitotically active under normal conditions. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 939-955, 2016.

  12. In vivo formation of nitrosocarbamates in the stomach of rats and guinea pigs

    SciTech Connect

    Rickard, R.W.; Dorough, H.W.

    1984-01-01

    The N-nitrosocarbamates are potent mutagens and carcinogens and have been synthesized under acid conditions that prevail in the human stomach. However, it has never been documented that nitrosocarbamates are actually formed in vivo in the stomach of any mammalian species. Using /sup 14/C-labeled carbaryl and carbofuran, attempts were made to isolate the nitroso derivatives from the stomach contents of rats and guinea pigs treated orally with the carbamate and sodium nitrite. Only trace quantities of nitrocarbamate were recovered from the rat stomach, whereas 0.5 to 2.0% of the carbamate doses were isolated as the nitroso derivative from the contents of the guinea pig stomach. The rather low apparent yields resulted in part from the instability of the nitrosocarbamates and from absorption of the carbamate and/or nitrosocarbamate from the stomach. Higher rates of synthesis were indicated by incubating the carbamates with sodium nitrite in the presence of the stomach contents at 37/sup 0/C for 15 min. About 30% nitrosation occurred with the guinea pig and about 0.5% with the rat. The difference was attributed to the pH of the gastric contents. For the rat, the pH ranged from 3 to 5; gastric contents of the guinea pig had a pH between 1 and 2. Since the pH of the human stomach is also in the pH 1-2 range, it is likely that nitrosation of carbamates in humans would be very similar to that in the guinea pig. 21 references, 3 figures, 3 tables.

  13. Metabolism and disposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin in guinea pigs

    SciTech Connect

    Olson, J.R.

    1986-09-15

    Marked interspecies variability exists in the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with the guinea pig being the mammalian species most sensitive to the acute toxicity of TCDD. The metabolism and disposition of TCDD was investigated in guinea pigs for 45 days following a single exposure to purified (/sup 3/H)TCDD (0.56 microgram/kg, ip). Guinea pigs included in the toxicokinetic study gained body weight, maintained a normal relative body composition, and exhibited no gross signs of toxicity during the 45-day study. Approximately 36% of the dose of TCDD-derived /sup 3/H remained in the adipose tissue at 45 days following exposure to (/sup 3/H)TCDD, while the liver, pelt, and skeletal muscle and carcass each contained about 7% of the administered dose. Although most of the TCDD-derived radioactivity in liver, kidney, perirenal adipose tissue, and skeletal muscle represented unchanged TCDD, from 4 to 28% of the /sup 3/H was associated with metabolites of TCDD. This unexpected finding suggests that TCDD metabolites are not efficiently excreted from guinea pigs. The urinary and fecal excretion of TCDD-derived radioactivity followed apparent first-order kinetics, with an elimination half-life of 93.7 +/- 15.5 days (mean +/- SD). HPLC analysis of urine and bile from (/sup 3/H)TCDD-treated guinea pigs showed that all of the radioactivity represented metabolites of TCDD, indicating that these routes of elimination are dependent on prior metabolism of TCDD. However, 70 to 90% of the radioactivity in fecal samples was found to represent unmetabolized TCDD throughout the 45-day excretion study. The presence of TCDD in feces and its absence in bile suggest that the fecal excretion of unchanged TCDD resulted from the direct intestinal elimination of the lipophilic toxin.

  14. Guinea pig protection test as indicator of potency of oil emulsion foot-and-mouth disease vaccines.

    PubMed

    Black, L; Pullen, L; Boge, A

    1985-09-01

    A vaccine potency test is described involving virus challenge to six groups of 10 guinea pigs at five weeks after vaccination. Sixteen oil emulsion foot-and-mouth disease vaccines were so tested and nine retested after storage at 4 degrees C for up to 28.3 months. The results were compared with those of the routinely used oil emulsion vaccine potency test (protection afforded to eight pigs challenged 21 days after vaccination). When guinea pig estimates of 3 log2 PD50 or more were obtained, then, with one exception, the batches protected all or almost all pigs from challenge, but when the guinea pig estimates were less than 1 log2 PD50, the vaccines failed to protect five out of eight pigs. The sensitivity and reproducibility of the guinea pig method, established by repeated tests on two vaccine batches, seemed acceptable. The results suggested that guinea pig estimates might provide a suitable substitute for pig challenge potency tests because they reflected the potency of the vaccines, were likely to involve smaller standard errors and caused less discomfort to animals. PMID:2999930

  15. Semicarbazide-sensitive amine oxidase activity of guinea pig dorsal skin.

    PubMed

    Buffoni, F; Cambi, S; Banchelli, G; Ignesti, G; Pirisino, R; Raimondi, L

    1994-01-01

    A semicarbazide-sensitive amine oxidase activity with a high affinity for benzylamine (Bz.SSAO) (E.C. 1.4.3.6) is present in guinea pig dorsal skin. This enzymic activity oxidized benzylamine, histamine, 1,4-methylhistamine and acetylputrescine and was inhibited by semicarbazide and by B24 (3,5-diethoxy-4-aminomethylpyridine), a selective inhibitor of Bz.SSAO enzymes. It cross reacted with the antibodies raised against pure pig plasma benzylamine oxidase. Immunohistochemistry showed that it was localized in fibroblasts. Bz.SSAO activity of guinea pig dorsal skin increased during the process of skin healing. A treatment of the wounds with 3 micrograms of b-FGF significantly accelerated the process of skin healing and the increase of Bz.SSAO activity. PMID:7931260

  16. Detection of Aeromonas caviae in the common housefly Musca domestica by culture and polymerase chain reaction.

    PubMed

    Nayduch, D; Honko, A; Noblet, G P; Stutzenberger, F

    2001-12-01

    Aeromonas caviae has been implicated in diarrhoeal disease of livestock and humans. The potential role of houseflies in the epidemiology of this pathogen was investigated by examining the prevalence of A. caviae in houseflies collected from two South Carolina farms and one restaurant. Isolation was accomplished by culture of flies in alkaline peptone water followed by identification with Aeromonas-specific PCR using novel primers (APW-PCR). All isolates cultured from houseflies were identified as A. caviae by biochemical characteristics and direct sequencing approximately 800 bp of the 16S rRNA gene. Aeromonas caviae was detected in 78% (272/349) dairy farm flies, 55% (54/99) pig farm flies and 39% (77/200) restaurant flies. Faeces from cows and pigs at the farms also were positive for A. caviae (58% and 100%, respectively). The APW PCR method provided a rapid, convenient way to identify A. caviae from faeces and houseflies that contained hundreds of bacterial species.

  17. Animal model studies of genital chlamydial infections. Immunity to re-infection with guinea-pig inclusion conjunctivitis agent in the urethra and eye of male guinea-pigs.

    PubMed

    Howard, L V; O'Leary, M P; Nichols, R L

    1976-08-01

    A previous report demonstrated that male guinea-pigs could be infected in the urethra with guinea-pig inclusion conjunctivitis (GPIC) agent and that the infection was transmitted during mating from infected males to females. In the experiments reported here, inoculation of male guinea-pigs in the urethra with GPIC organisms resulted in infection which subsided spontaneously in about 2 weeks. Males were demonstrated to be completely resistant to urethral challenge with 10(3)ID50 when tested 6 weeks after urethral infection. These guinea-pigs, immune to re-infection of the urethra, remained susceptible to infection of the eye, but this ocular infection was shorter in duration than that in previously uninfected control animals. Infection in the eye resulted in immunity to both ocular and urethral infection when animals were challenged 6 weeks after the ocular infection.

  18. Identification, evolution, and regulation of expression of Guinea pig trappin with an unusually long transglutaminase substrate domain.

    PubMed

    Furutani, Yutaka; Kato, Akira; Fibriani, Azzania; Hirata, Taku; Kawai, Ryoji; Jeon, Ju-Hong; Fujii, Yasuhisa; Kim, In-Gyu; Kojima, Soichi; Hirose, Shigehisa

    2005-05-27

    Trappins are found in human, bovine, hippopotamus, and members of the pig family, but not in rat and mouse. To clarify the evolution of the trappin genes and the functional significance of their products, we isolated the trappin gene in guinea pig, a species belonging to a rodent family distinct from rat and mouse. Guinea pig trappin was confirmed to encode the same domain structure as trappin, consisting of a signal sequence, an extra large transglutaminase substrate domain, and a whey acidic protein motif. Northern blot analysis and in situ hybridization histochemistry as well as immunohistochemistry demonstrated that guinea pig trappin is expressed solely in the secretory epithelium of the seminal vesicle and that its expression is androgen-dependent. We confirmed that guinea pig trappin is cross-linked by prostate transglutaminase and that the whey acidic protein motif derived from guinea pig trappin has an inhibitory activity against leukocyte elastase. Genome sequence analysis showed that guinea pig trappin belongs to the family of REST (rapidly evolving seminal vesicle transcribed) genes. PMID:15778505

  19. Afterhyperpolarization current in myenteric neurons of the guinea pig duodenum.

    PubMed

    Vogalis, F; Furness, J B; Kunze, W A

    2001-05-01

    Whole cell patch and cell-attached recordings were obtained from neurons in intact ganglia of the myenteric plexus of the guinea pig duodenum. Two classes of neuron were identified electrophysiologically: phasically firing AH neurons that had a pronounced slow afterhyperpolarization (AHP) and tonically firing S neurons that lacked a slow AHP. We investigated the properties of the slow AHP and the underlying current (I(AHP)) to address the roles of Ca(2+) entry and Ca(2+) release in the AHP and the characteristics of the K(+) channels that are activated. AH neurons had a resting potential of -54 mV and the AHP, which followed a volley of three suprathreshold depolarizing current pulses delivered at 50 Hz through the pipette, averaged 11 mV at its peak, which occurred 0.5-1 s following the stimulus. The duration of these AHPs averaged 7 s. Under voltage-clamp conditions, I(AHP)'s were recorded at holding potentials of -50 to -65 mV, following brief depolarization of AH neurons (20-100 ms) to positive potentials (+35 to +50 mV). The null potential of the I(AHP) at its peak was -89 mV. The AHP and I(AHP) were largely blocked by omega-conotoxin GVIA (0.6-1 microM). Both events were markedly decreased by caffeine (2-5 mM) and by ryanodine (10-20 microM) added to the bathing solution. Pharmacological suppression of the I(AHP) with TEA (20 mM) or charybdotoxin (50-100 nM) unmasked an early transient inward current at -55 mV following step depolarization that reversed at -34 mV and was inhibited by niflumic acid (50-100 microM). Mean-variance analysis performed on the decay of the I(AHP) revealed that the AHP K(+) channels have a mean chord conductance of ~10 pS, and there are ~4,000 per AH neuron. Spectral analysis showed that the AHP channels have a mean open dwell time of 2.8 ms. Cell-attached patch recordings from AH neurons confirmed that the channels that open following action currents have a small unitary conductance (10-17 pS) and open with a high probability (

  20. Inhibition of the effects of thrombin on guinea pig platelets by the diacylglycerol lipase inhibitor RHC 80267

    SciTech Connect

    Amin, D.; Sutherland, C.A.; Khandwala, A.S.; Jamall, I.S.; Kapoor, A.L.

    1986-10-01

    Phospholipase C (PLC) and diacylglycerol lipase (DGL) activities were found in guinea pig platelet microsome preparations. No phospholipase A2 (PLA2) activity was detected. RHC 80267 (1,6-di (0-(carbamoyl) cyclohexanone oxime)hexane) inhibited DGL activity (IC50 = 4 uM) from guinea pig platelet microsomes but had no effect on PLC. RHC 80267 inhibited platelet aggregation (IC50 = 11 uM), release of arachidonic acid (AA), its metabolites, and ATP (IC50 = 4.5 uM) when guinea pig platelets were challenged with a low concentration of thrombin. We propose that PLC-DGL is an important enzymatic pathway for the release of AA in guinea pig platelets.

  1. [Effect produced by the alkaloid fraction of Mimosa tenuiflora (tepescohuite) on the peristaltic reflex of the guinea pig ileum].

    PubMed

    Meckes-Lozoya, M; Lozoya, X; González, J L; Martínez, M

    1990-01-01

    An alkaloidal fraction was obtained from Mimosa tenuiflora (Willd.) Poir (tepescohuite) trunk bark. The product contained mainly an indolealkylamine and three minor alkaloids. This fraction inhibited the peristaltic reflex in the guinea-pig isolated ileum in vitro.

  2. Improved facility and sensitivity in the use of guinea pigs for the isolation of Legionella pneumophila from cooling tower water

    SciTech Connect

    Leinbach, E.D.; Winkler, H.H.; Wood, D.O.; Coggin, J.H. Jr.

    1983-03-01

    The established criteria for the determination of the optimum time for the sacrifice of guinea pigs inoculated with samples of cooling tower water were found to be inadequate for the detection of low levels of Legionella pneumophila. By ignoring the requirement for fever and by sequentially sacrificing the infected guinea pigs on days 3 through 5 postinoculation, we simplified the procedure, and the sensitivity of detection was improved a great deal.

  3. An enzyme-linked immunosorbent assay (ELISA) for anti-chlamydial secretory immunoglobulin A in guinea pig tears.

    PubMed

    Finney, P M; Bushell, A C

    1986-01-22

    A method is described which permits the assay of specific secretory immunoglobulin A (sIgA) antibodies produced by guinea pigs in response to ocular infection with the guinea pig inclusion conjunctivitis strain of Chlamydia psittaci (GPIC agent). The enzyme-linked immunosorbent assay (ELISA) developed was shown to be more sensitive and less subjective than the micro-immunofluorescence assay as a means of assaying specific antibody.

  4. Nickel allergy: tolerance to metallic surface-plated samples in nickel-sensitive humans and guinea pigs.

    PubMed

    Cavelier, C; Foussereau, J; Gille, P; Zissu, D

    1988-11-01

    The purpose of this work is to evaluate in nickel-sensitive patients and guinea pigs the tolerance to nickel samples, surface-plated with one or several metals of varying structures and thicknesses. All the metal samples elicited allergic reactions in the guinea pig. In humans, absolute tolerance was not observed for any sample. In humans, the interposing of a layer of bright copper between nickel and surface chrome greatly increased the tolerance.

  5. Activation of the alternative complement pathway by natural antibody to glycolipids in guinea-pig serum.

    PubMed Central

    Okada, N; Yasuda, T; Tsumita, T; Okada, H

    1983-01-01

    Liposomes containing paragloboside (PG) on their membrane were readily lysed by C4-deficient guinea-pig serum (C4D-GPS) through activation of the alternative complement pathway (ACP). Therefore we examined the reactivity of several types of guinea-pig serum (GPS) on PG-liposomes and determined that all GPS except that from specific pathogen-free (SPF) Hartley guinea-pigs had lytic capacity in Mg-EGTA-GVB (gelatin veronal-buffered saline containing Mg++ and ethyleneglycol-bis(beta-aminoethyl ether)N,N'-tetraacetate). This lytic capacity of GPS corresponded with the amount of natural antibody to PG in those sera. Although GPS of SPF guinea-pigs (SPF-GPS) could not lyse PG-liposomes in Mg-EGTA-GVB, it could lyse the liposomes when heated C4D-GPS or Hartley GPS was added. Natural antibody to PG in the heated sera was regarded to have sensitized PG-liposomes to lysis by SPF-GPS via ACP activation. Since the antibody to PG-liposomes was removed by lacto-N-nor-hexaosylceramide which has the same chemical structure in the terminal oligosaccharide, the antibody to PG in GPS was suggested to have a specificity to the terminal structure of oligosaccharide shared by lacto-N-nor-hexaosylceramide. Furthermore, the IgM fraction, which had been prepared by gel filtration of heated C4D-GPS on a Sephadex G200 column, could also sensitize PG-liposomes to lytic reaction of SPF-GPS in Mg-EGTA-GVB. This sensitizing capacity of heated C4D-GPS was suppressed by absorption of the serum or its IgM fraction with anti-guinea-pig mu-chain antibody coupled to Sepharose. Therefore, it was concluded that the lysis of PG-liposomes by GPS in Mg-EGTA-GVB was a result of ACP activation mediated by natural antibodies to PG of the IgM type which are present in usual GPS. This conclusion indicated that natural antibodies of the IgM type might play a role with ACP in host defence, especially in C4-deficient guinea-pigs where the classical complement pathway is impaired. PMID:6193057

  6. Bicarbonate effects, electromotive forces and potassium effluxes in rabbit and guinea-pig gall-bladder.

    PubMed

    Cremaschi, D; Meyer, G; Rossetti, C

    1983-02-01

    The stimulating effect of external HCO3- on Na+ salt transport has been examined in rabbit and guinea-pig gall-bladder by electrophysiological methods, as a sequel to a previous study carried out by radiochemical techniques. At steady state, cell K+ activity was found to be significantly reduced in the presence of HCO3-, whereas cell Na+ activity significantly increased; in parallel the apical membrane p.d. was depolarized; K+ equilibrium potential was higher than membrane p.d. in every case. The apical p.d. dependence on K+ was unaffected by HCO3-, but in the guinea-pig it was affected by Cl-. Rapid increases in HCO3- concentration on the luminal side caused a depolarization of the apical p.d. of the guinea-pig within about 30 sec, an effect that did not occur if the tissue was pre-treated with 10(-4) M-acetazolamide; the epithelial resistance and apical/basolateral resistance ratio were unchanged in all cases. The primary action of HCO3- is confirmed to be on the apical membrane; an HCO3- conductance does not seem to be present at this level, either in the rabbit or guinea-pig, nor does HCO3- affect Na+ influx through the apical conductive pathway, so that all the stimulating effects of the anion are confirmed to be on the neutral transports of Na+ salts; in spite of this, the apical electromotive force is modified due to the changed cell K+ activity. The rapid depolarization caused by the anion in the guinea-pig is in agreement with an HCO3- electrogenic secretion and/or a basolateral conductance for the anion. Polyelectrolyte dissociation from protons increases in the absence of external HCO3-: the negative charges are mainly counterbalanced by bound Na+ in the rabbit and by free K+ in the guinea-pig. K+ leakage from the cell into the lumen is calculated to be minimal in the rabbit and all K+ lost could be reabsorbed through the paracellular pathways; K+ efflux to the subepithelial layer via conductive routes is insufficient to account for the over-all K

  7. Opioid binding sites in the guinea pig and rat kidney: Radioligand homogenate binding and autoradiography

    SciTech Connect

    Dissanayake, V.U.; Hughes, J.; Hunter, J.C. )

    1991-07-01

    The specific binding of the selective {mu}-, {delta}-, and {kappa}-opioid ligands (3H)(D-Ala2,MePhe4,Gly-ol5)enkephalin ((3H) DAGOL), (3H)(D-Pen2,D-Pen5)enkephalin ((3H)DPDPE), and (3H)U69593, respectively, to crude membranes of the guinea pig and rat whole kidney, kidney cortex, and kidney medulla was investigated. In addition, the distribution of specific 3H-opioid binding sites in the guinea pig and rat kidney was visualized by autoradiography. Homogenate binding and autoradiography demonstrated the absence of {mu}- and {kappa}-opioid binding sites in the guinea pig kidney. No opioid binding sites were demonstrable in the rat kidney. In the guinea pig whole kidney, cortex, and medulla, saturation studies demonstrated that (3H)DPDPE bound with high affinity (KD = 2.6-3.5 nM) to an apparently homogeneous population of binding sites (Bmax = 8.4-30 fmol/mg of protein). Competition studies using several opioid compounds confirmed the nature of the {delta}-opioid binding site. Autoradiography experiments demonstrated that specific (3H)DPDPE binding sites were distributed radially in regions of the inner and outer medulla and at the corticomedullary junction of the guinea pig kidney. Computer-assisted image analysis of saturation data yielded KD values (4.5-5.0 nM) that were in good agreement with those obtained from the homogenate binding studies. Further investigation of the {delta}-opioid binding site in medulla homogenates, using agonist ((3H)DPDPE) and antagonist ((3H)diprenorphine) binding in the presence of Na+, Mg2+, and nucleotides, suggested that the {delta}-opioid site is linked to a second messenger system via a GTP-binding protein. Further studies are required to establish the precise localization of the {delta} binding site in the guinea pig kidney and to determine the nature of the second messenger linked to the GTP-binding protein in the medulla.

  8. Capillarity and oxygen diffusion distances of the soleus muscle of guinea pigs and rats. Effects of hyperthyroidism.

    PubMed

    Sillau, A H

    1985-01-01

    The relationship between capillarity and oxidative capacity in the soleus muscle of rats and guinea pigs injected with triiodothyronine (T3) or with saline for up to 4 weeks was studied. The rats' soleus weight and FCSA were not affected by T3, but the guinea pigs that received T3 had smaller muscle weight and FCSA than the controls. The activities of cytochrome c oxidase and citrate synthase were significantly (41 and 65%) higher in the T3 than in the control rats. T3 administration did not affect the activities of these enzymes in the soleus of the guinea pigs. Capillary density (CD) was higher in T3 rats (892 +/- 80 vs 622 +/- 54 caps/mm2), and in T3 guinea pigs (1219 +/- 95 vs 739 +/- 142 caps/mm2). The higher CD in T3 rats was due to growth of new microvessels, while in the T3 guinea pigs it was due to a reduction in FCSA. Mean and maximal diffusion distances evaluated by the closest individual method were reduced by 2.02 and 3.37 microns in rats, and by 3.73 and 6.16 microns in guinea pigs. The magnitude of the reduction in diffusion distances brought about by the increased capillary density was partially offset by a concomitant change in the capillary arrangement from an ordered (hexagonal), towards a random distribution. These results seem to indicate that skeletal muscle capillarity is not necessarily determined by the oxidative capacity of the fibers.

  9. Effects of sulfuric acid mist inhalation on mucous clearance and on airway fluids of rats and guinea pigs

    SciTech Connect

    Wolff, R.K.; Henderson, R.F.; Gray, R.H.; Carpenter, R.L.; Hahn, F.F.

    1986-01-01

    The responses of guinea pigs and rats to inhaled sulfuric acid aerosols were compared to define species differences and to determine the small-animal model most relevant to human exposures. Rats were exposed for 6 hr to 1, 10, and 100 mg H/sub 2/SO/sub 4//m/sup 3/. Guinea pigs were exposed for 6 h to 1, 10, and 27 mg H/sub 2/SO/sub 4//m/sup 3/. Tracheal mucous clearance of guinea pigs was slowed 1 d after exposures to 1 mg H/sub 2/SO/sub 4//m/sup 3/. A tendency toward faster clearance was observed at high concentrations of H/sub 2/SO/sub 4/ for both guinea pigs and rats (statistically significant only for the rats). The speeding of mucous clearance was correlated with increases in airway sialic acid and also with the appearance of excess tracheal secretions, detected using scanning electron microscopy in both rats and guinea pigs. The responses of guinea pigs to sulfuric acid exposures were more similar to those reported for humans than were those of rats.

  10. Increased severity of tuberculosis in Guinea pigs with type 2 diabetes: a model of diabetes-tuberculosis comorbidity.

    PubMed

    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

    2014-04-01

    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.

  11. Conventional anticonvulsant drugs in the guinea-pig kindling model of partial seizures: effects of acute phenytoin.

    PubMed

    Gilbert, T H; Bharadia, V; Teskey, G C

    2001-10-01

    This study addressed some of the controversial issues surrounding the anticonvulsant effect of phenytoin, and the predictive validity of the guinea-pig kindling model for the screening of anticonvulsant drugs. Following an intraperitoneal injection of either 50 or 75 mg/kg phenytoin, we analysed plasma concentrations of phenytoin at various time intervals. Behavioural toxicity was assessed at 0.5 h postinjection using quantitative locomotor tests, as well as scores on a sedation/muscle relaxation rating index. The anticonvulsant efficacy of phenytoin was evaluated from measurements of afterdischarge threshold (ADT), afterdischarge duration (ADD) and behavioural seizure severity at three phases of kindling: non-kindled, kindling acquisition (early and late) and kindled (50+ ADs). ADD and seizure severity were also measured in response to both threshold and suprathreshold kindling stimulation. Plasma levels of phenytoin corresponded to the human therapeutic range at the time of behavioural testing and kindling. Phenytoin did not exert significant adverse effects in guinea-pigs on both the behavioural tests and rating index. Phenytoin increased ADT in non-kindled and kindled guinea-pigs and effectively reduced ADD and seizure severity, indicating that the guinea-pig model correctly predicted phenytoin's anticonvulsant effect. Phenytoin produced reliable anticonvulsant activity in the guinea-pig at threshold stimulation but a somewhat reduced efficacy on seizure severity at suprathreshold stimulation intensities. Kindling in the guinea-pig is a valid model of human partial seizures.

  12. Partial protection against genital reinfection by immunization of guinea-pigs with isolated outer-membrane proteins of the chlamydial agent of guinea-pig inclusion conjunctivitis.

    PubMed

    Batteiger, B E; Rank, R G; Bavoil, P M; Soderberg, L S

    1993-12-01

    Because partial protection against reinfection is induced by experimental infection in the guinea-pig model of genital chlamydial infection, we sought to induce immunity by immunization. Female guinea-pigs were immunized subcutaneously with the major outer-membrane protein (MOMP) and the 61 kDa cysteine-rich outer-membrane protein (61 kDa) of the agent of guinea-pig inclusion conjunctivitis (GPIC) eluted from SDS-polyacrylamide gels (SDS-MOMP, SDS-61 kDa). Post-immunization sera and secretions contained antibodies to the SDS-purified proteins at high titre as measured by immunoblotting, whereas enzyme immunoassays (EIA) using whole elementary bodies as antigen showed significantly lower titres (P < 0.001). Likewise, blastogenic responses of peripheral mononuclear cells to GPIC elementary bodies were weak. Animals immunized with SDS-MOMP and SDS-61 kDa were fully susceptible to intravaginal challenge, as were control animals immunized with buffer without protein. Another group of animals were immunized with material prepared by extraction of chlamydial outer-membrane complexes with octyl beta-D-glucopyranoside (OGP) and dithiothreitol, which consisted largely of MOMP (OGP-MOMP). In contrast to the SDS-MOMP group, sera and secretions in the OGP-MOMP group showed high titres in EIA, and high titre antibodies to MOMP by immunoblot; however, most animals also had antibodies to 61 kDa, 72 kDa and ca. 84 kDa outer-membrane proteins. OGP-MOMP animals were partially protected against genital challenge as evidenced by low inclusion scores compared to control animals, although duration of infection measured by culture isolation was similar to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Reduction of biliverdin and placental transfer of bilirubin and biliverdin in the pregnant guinea pig.

    PubMed Central

    McDonagh, A F; Palma, L A; Schmid, R

    1981-01-01

    Biliverdin was reduced to bilirubin in pregnant and foetal guinea pigs, and the 100000 g supernatant from homogenates of foetal liver, placenta and maternal liver showed high biliverdin reductase activity. The placental transport of unconjugated bilirubin and biliverdin was compared by injecting unlabelled and radiolabelled pigments into the foetal or maternal circulation and analysing blood collected from the opposite side of the placenta. Injected bilirubin crossed the placenta from foetus to mother and vice versa, but injected biliverdin did not appear to cross without prior reduction to bilirubin. The guinea-pig placenta is apparently more permeable to bilirubin than biliverdin. Reduction of biliverdin to bilirubin in the foetus may, therefore, be essential for efficient elimination of haem catabolites from the foetus in placental mammals. PMID:7305981

  14. Induction of contact drematitis in guinea pigs by quaternary ammonium compounds: the mechanisms of antigen formation

    SciTech Connect

    Schallreuter, K.R.; Schulz, K.H.; Wood, J.M.

    1986-12-01

    Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane lipids in forming immunogenic complexes. This surface complexation phenomenon was confirmed by using a spin-labeled quaternary ammonium salt which competed for binding sites to the surface of epidermal cells in vivo. Electron spin resonance was used to demonstrate that stable ion-pairs are formed between binding sites and the two allergenic preservatives. Furthermore, information was obtained on the kinetics of immunogenic complex formation as well as on the position and orientation of the quaternary ammonium ion at the cell surface.

  15. Further characterization of presynaptic beta-adrenoceptors in guinea-pig pulmonary arteries.

    PubMed

    Misu, Y; Kuwahara, M; Kaiho, M; Kubo, T

    1983-07-22

    Presynaptic beta-adrenoceptors were further characterized in spiral strips of guinea-pig pulmonary arteries preloaded with [3H]norepinephrine. l-Metoprolol (3 X 10(-6) M) inhibited isoproterenol (3 X 10(-7) M)-induced increases in 3H efflux by transmural field stimulation, whereas the d-isomer produced no inhibition. However, IPS 339, H 35/25, butoxamine and metoprolol (3 X 10(-6) M) antagonized salbutamol (3 X 10(-7) M)-induced increases in the parameter, whereas acebutolol, bevantolol and practolol (3 X 10(-6) M) produced no antagonism. Presynaptic beta-adrenoceptors in guinea-pig pulmonary arteries appear to have characteristics similar to those postsynaptic classical beta-adrenoceptors.

  16. Scanning electron microscopy of experimental Trichophyton mentagrophytes infections in guinea pig skin.

    PubMed Central

    Hutton, R D; Kerbs, S; Yee, K

    1978-01-01

    Trichophyton mentagrophytes invasion of guinea pig skin was examined by scanning electron microscopy. Biopsies were obtained daily for 12 days from experimental infection sites. Dermatophyte invasion, examined in detail by scanning electron microscopy of cross-sectioned, prefixed skin was evidenced by: the appearance of hyphae within the stratum corneum; follicular invasion by hyphae, which remained initially within the follicle wall; emergence of the hyphae from the wall into the follicular canal; proliferation of the fungus down the follicle, with furrowing of the follicle wall and hair shaft cuticle; penetration of hyphae into the hair shaft by subcuticular and transcuticular routes; and massive peripilar hyphal proliferation with arthrosporogenesis. A three-dimensional perception of the invasion sequence of a dermatophyte in guinea pig skin was obtained by scanning electron microscopy. Images PMID:711318

  17. Extraction of an incisor embedded within the nasal cavity in two guinea pigs

    PubMed Central

    KIDO, Nobuhide; ONO, Kaori; OMIYA, Tomoko; OGUCHI, Yukio; SETOGAWA, Moemi; MACHIDA, Yuuki

    2015-01-01

    Oral examination of two guinea pigs revealed that the unilateral incisor was absent. On radiographic examination, the incisor was identified within the nasal cavity in both patients. Under anesthesia in both patients, the skin was incised from the nostril to 1.5 cm proximal, and the premaxilla and part of the maxilla were exposed. The bone was removed using a surgical drill, and the incisor was exposed in the nasal cavity. The root was grasped with forceps and carefully extracted as it was degraded and very fragile. Diagnosis was easy using oral and radiographic examination. In guinea pig patients where an incisor is absent on oral examination, this condition should be considered. PMID:26118492

  18. "Rickettsia amblyommii" induces cross protection against lethal Rocky Mountain spotted fever in a guinea pig model.

    PubMed

    Blanton, Lucas S; Mendell, Nicole L; Walker, David H; Bouyer, Donald H

    2014-08-01

    Rocky Mountain spotted fever (RMSF) is a severe illness caused by Rickettsia rickettsii for which there is no available vaccine. We hypothesize that exposure to the highly prevalent, relatively nonpathogenic "Rickettsia amblyommii" protects against R. rickettsii challenge. To test this hypothesis, guinea pigs were inoculated with "R. amblyommii." After inoculation, the animals showed no signs of illness. When later challenged with lethal doses of R. rickettsii, those previously exposed to "R. amblyommii" remained well, whereas unimmunized controls developed severe illness and died. We conclude that "R. amblyommii" induces an immune response that protects from illness and death in the guinea pig model of RMSF. These results provide a basis for exploring the use of low-virulence rickettsiae as a platform to develop live attenuated vaccine candidates to prevent severe rickettsioses.

  19. Adapted Lethality: What We Can Learn from Guinea Pig-Adapted Ebola Virus Infection Model

    PubMed Central

    Cheresiz, S. V.; Semenova, E. A.; Chepurnov, A. A.

    2016-01-01

    Establishment of small animal models of Ebola virus (EBOV) infection is important both for the study of genetic determinants involved in the complex pathology of EBOV disease and for the preliminary screening of antivirals, production of therapeutic heterologic immunoglobulins, and experimental vaccine development. Since the wild-type EBOV is avirulent in rodents, the adaptation series of passages in these animals are required for the virulence/lethality to emerge in these models. Here, we provide an overview of our several adaptation series in guinea pigs, which resulted in the establishment of guinea pig-adapted EBOV (GPA-EBOV) variants different in their characteristics, while uniformly lethal for the infected animals, and compare the virologic, genetic, pathomorphologic, and immunologic findings with those obtained in the adaptation experiments of the other research groups. PMID:26989413

  20. Schistosoma mansoni: migration potential of normal and radiation attenuated parasites in naive guinea pigs

    SciTech Connect

    Kamiya, H.; McLaren, D.J.

    1987-02-01

    Compressed tissue autoradiography using (75Se)selenomethionine labelled parasites has been used to investigate the migration potential of normal and radiation attenuated cercariae of Schistosoma mansoni in naive guinea pigs. By Day 14 after infection. 44% of normal parasites were detected as reduced silver foci in the liver; this value corresponded well with the number of liver parasites recovered by retrograde perfusion of the hepatic portal system on Day 42 (42% of the challenge). In contrast, cercariae subjected to 50 krad of gamma irradiation failed to migrate out of the skin. The migration capacity of 20 krad irradiated parasites was less severely affected in that about half of the challenge parasites reached the lungs, but virtually none moved to the liver. These data are discussed in relation to the kinetics of immunity induced in guinea pigs by infection or vaccination with normal or radiation attenuated parasites.

  1. [Morphological changes in the respiratory tract of guinea pigs exposed to kerosene aerosol].

    PubMed

    Sanabria, J; Noa, M; Casacó, A; González, R

    1984-01-01

    It's well known that there exists a high correlation between daily usage of Kerosene and the appearance of dyspnea in healthy humans and in asthmatic patients. Our aim is to study the histological alterations of the respiratory tract of guinea pigs submitted to Kerosene aerosol. It was administered to male guinea pigs fifteen minutes daily for a month. Fragments of trachea and lungs were processed for histological studies. Erosion of tracheal epithelium and inflammatory infiltration were observed. Lungs presented with thickening of the interalveolar septa. The eosinophilic infiltration may represent an immunological response resembling reactions of immediate hypersensitivity. The morphological alterations may be induced by toxic products of Kerosene such as sulphur impurities that act as mucosal irritants which damage defense mechanisms of the organism.

  2. Effects of nedocromil sodium on antigen-induced conjunctivitis in guinea pigs.

    PubMed

    Hoyos, L; Norris, A; Vargaftig, B B

    2000-01-01

    We evaluated nedocromil sodium in a guinea pig model of allergic conjunctivitis. Ten days after the animals were passively sensitized to ovalbumin, nedocromil sodium (2 mg) or normal saline was instilled into the conjunctival sac, followed by antigen challenge with ovalbumin (100 micrograms or 300 micrograms/10 microL). Conjunctival hyperemia, edema, and eyelid edema were evaluated at 10 minutes and 4 hours in the 100-microgram ovalbumin group. Eyes with nedocromil sodium exhibited fewer early and late clinical signs of allergic conjunctivitis than control eyes. Infiltrating eosinophils were counted at 24 hours in the 300-microgram ovalbumin group. Nedocromil sodium inhibited antigen-induced eosinophil infiltration into the limbus, fornix, and eyelids by 77%, 66%, and 74%, compared with controls. Nedocromil sodium can effectively suppress early- and late-phase conjunctival hyperemia, conjunctival edema, eyelid edema, and eosinophil infiltration in the guinea pig passive-sensitization model. Nedocromil sodium may represent a versatile option for the treatment of allergic conjunctivitis.

  3. Genital herpes in guinea pigs: pathogenesis of the primary infection and description of recurrent disease.

    PubMed

    Stanberry, L R; Kern, E R; Richards, J T; Abbott, T M; Overall, J C

    1982-09-01

    Guinea pigs inoculated intravaginally with herpes simplex virus type 2 (HSV-2) developed a self-limiting infection characterized by vesiculo-ulcerative lesions on the external genital skin, urinary retention, and hindlimb paralysis. Infection rarely resulted in death. Virologic, histologic, and immunoperoxidase data suggested the following scheme for viral pathogenesis: initial replication in the introitus, vagina, and bladder; spread via sensory nerves to the lumbosacral dorsal root ganglia and spinal cord, and transmission via peripheral nerves to the external genital skin to produce the characteristic lesions. After recovery from primary infection, animals developed recurrent vesicular lesions, shed virus from genital sites in the absence of lesions, and harbored latent HSV-2 in dorsal root ganglia. Genital infection in the guinea pig shares many features with genital herpes in humans and provides a model to explore mechanisms of latency and reactivation and to evaluate several methods for control of recurrent disease.

  4. Effect of Artocarpus integer lectin on functional activity of guinea-pig complement.

    PubMed

    Hashim, O H; Gendeh, G S; Cheong, C N; Jaafar, M I

    1994-03-01

    The effect of Artocarpus integer lectin (lectin C) on the functional activity of guinea-pig complement was investigated. Purified and crude extract of lectin C from six cultivars of Artocarpus integer seeds were found to consume complement and thus decreased the complement-induced haemolytic activity of sensitized sheep erythrocytes. The change in the complement-mediated haemolytic activity was significantly decreased when incubation of the lectins was performed in the presence of melibiose. The reversal effect of the carbohydrate, which is a potent inhibitor of the lectin's binding to O-linked oligosaccharides of glycoprotein, demonstrate involvement of the lectins interaction with O-glycans of glycoproteins in the consumption of guinea-pig complement.

  5. In vivo cystometrogram studies in urethane-anesthetized and conscious guinea pigs.

    PubMed

    Peterson, J S; Hanson, R C; Noronha-Blob, L

    1989-05-01

    Urinary bladder cystometry using urethral catheters is described in vivo in a urethane-anesthetized guinea pig preparation and compared to an awake-animal preparation in which surgically implanted catheters were used. Anticholinergic drugs dose-dependently inhibited the peak intravesical pressure (PvesP) to a maximum of approximately 80% but had no effect on other cystometrogram (CMG) parameters (threshold pressure, bladder capacity). Stereoselectivity was evident; dexetimide but not levetimide potently depressed PvesP. Oxybutynin was equipotent (ID50 approximately 0.15 mg/kg) in both preparations and showed a similar duration of action (t1/2 = 48-53 min). The data suggests that CMG parameters and the effects of oxybutynin were not affected by urethane anesthesia, making the in vivo urethane-anesthetized guinea pig preparation a valuable tool to evaluate both the filling and voiding phases of cystometry. PMID:2724992

  6. Zeta-crystallin, a novel protein from the guinea pig lens is related to alcohol dehydrogenases.

    PubMed

    Rodokanaki, A; Holmes, R K; Borrás, T

    1989-05-30

    zeta-Crystallin is a major component of the water-soluble proteins of the guinea pig lens. We have constructed a lens cDNA library from one- to seven-day-old guinea pigs in the plasmid Bluescript KS+ and used the 16 amino acid (aa) sequence of a CNBr peptide to design an oligodeoxyribonucleotide probe. Analysis of two positive clones and direct sequence of the 5' end of the RNA resulted in the completion of a most probably full-length mRNA comprising 1842 nucleotides (nt). The ATG start codon occurs 83 nt downstream from the 5' end. The open reading frame, ending with a stop codon at nt position 1070, predicts a protein of 328 aa with a calculated Mr of 35,071. Comparison of the amino acid sequence with the National Biomedical Research Foundation protein data base reveals a significant similarity of zeta-crystallin with the enzyme of the alcohol dehydrogenase family.

  7. Impaired performance on odor-aversion testing following prenatal aspartame exposure in the guinea pig.

    PubMed

    Dow-Edwards, D L; Scribani, L A; Riley, E P

    1989-01-01

    Pregnant guinea pigs were administered aspartame (500 mg/kg) in sesame oil by gavage or sesame oil alone between the day of conception and parturition. A nontreated control group was also maintained. There were no statistically significant effects of the treatment on maternal weight gain, litter size, or birth weight of the pups. Newborn pups were weighed daily and on day 15 were injected with either LiCl or saline and placed in a cage with vanilla odor for 30 min. Twenty-four hr later the pups were permitted to choose between vanilla and lemon odors in a preference test. While both the vehicle-treated control and nontreated control groups injected with LiCl showed a conditioned aversion to vanilla, the aspartame-treated pups injected with LiCl did not. These data indicate that aspartame exposure at 500 mg/kg throughout gestation disrupts odor-associative learning in 15-day-old guinea pigs.

  8. Existence of subtypes of gustducin-immunoreactive cells in the vallate taste bud of guinea pigs.

    PubMed

    Ohkubo, Yasuhiro; Yokosuka, Hiroyuki; Kumakura, Masahiko; Yoshie, Sumio

    2007-12-01

    Vallate taste buds in the guinea-pig tongue were immunohistochemically investigated with regard to the colocalization of gustducin with calbindin-D28K (=spot 35 protein) and type III inositol triphosphate receptor (IP(3)R-3) in order to characterize gustducin-immunoreactive cells. Individual taste bud cells ranged from totally immunopositive to totally immunonegative for these three molecules. Among the immunoreactive cells, gustducin-immunoreactive cells were divided into two cell populations: one immunopositive and the other immunonegative for calbindin-D28K. Applying our previous data to the present results, the former cells should belong to Type III cells designated by electron microscopy. This finding provides new evidence regarding the taste bud types of cells expressing gustducin in the guinea pig. PMID:18431029

  9. Quantitative analysis of squamous epithelium of normal palatal mucosa in guinea pigs.

    PubMed

    Andersen, L; Schroeder, H E

    1978-07-01

    The epithelium of intact guinea pig palate was subjected to stereologic analysis in a study of structural alterations in the keratinizing epithelium in response to wounding. Point counting procedures were employed to analyse electron micrographs sampled from three epithelial strata in biopsies collected from five animals. The differentiation pattern of the guinea pig palate epithelium displayed the following structural density gradients from basal to granular layers: descending gradients of metabolically active organelles, ascending gradient of bundled filaments coupled with the appearance of membrane coating granules and keratohyalin granules, and a plateau-like gradient of cytoplasmic ground substance. This pattern of epithelial differentiation is basically identical to that of human hard palate epithelium and epidermis. Regional and species variations in structure of keratinizing epithelia are suggested based on interepithelial differences in morphometric parameters.

  10. Macrophage activation of allogeneic lymphocyte proliferation in the guinea pig mixed leukocyte culture.

    PubMed

    Greineder, D K; Rosenthal, A S

    1975-05-01

    The role of the macrophage in the guinea pig mixed leukocyte culture was investigated. Macrophages obtained from oil-induced peritoneal exudates, peritoneal wash-out cells, spleen, and alveolar washings were found to be effective stimulators of allogeneic lymph node and splenic lymphocyte DNA synthesis. The stimulatory properties of macrophages proved radioresistant but viability dependent. Unfractionated lymph node cells or adherence column purified lymph node lymphocytes and thymocytes were only minimally active as stimulators, even in the presence of macrophages syngeneic to the responder lymphocytes. Allogeneic fibroblasts, polymorphonuclear leukocytes, L2C leukemia cells, and xenogeneic (murine) macrophages failed to simulate. These data provide evidence that the macrophage is the predominant stimulator of the mixed leukocyte culture in the guinea pig.

  11. [Breeding and management of mycobacteria-free guinea pigs (author's transl)].

    PubMed

    Kazda, J

    1976-08-01

    A number of mycobacterial species are detectable under conventional holding condition of guinea pigs. These mycobacteria originating in drinking water and litter caused cross reactions in the Jones-Mote hypersensitivity test. Using suitable precautions it was possible to breed and hold the animals mycobacteria-free. The precautions depend mainly in alteration of the wire mesh floor in cages to avoide the contact of the animals with the litter, in cleaning and desinfection of water bottles, in using of heated water and food and in the prevention of mycobacterial contamination from the staff. The control examination on mycobacteria without treating is given in details. Cases are refered in which a oral rece ption of mycobacteria can alter the immune response. The modification of guinea pigs management to the mycobacteria-free ones is possible in a short time and with minimal cost.

  12. Constitutive and allergen-induced expression of eotaxin mRNA in the guinea pig lung

    PubMed Central

    1995-01-01

    Eotaxin is a member of the C-C family of chemokines and is related during antigen challenge in a guinea pig model of allergic airway inflammation (asthma). Consistent with its putative role in eosinophilic inflammation, eotaxin induces the selective infiltration of eosinophils when injected into the lung and skin. Using a guinea pig lung cDNA library, we have cloned full-length eotaxin cDNA. The cDNA encodes a protein of 96 amino acids, including a putative 23-amino acid hydrophobic leader sequence, followed by 73 amino acids composing the mature active eotaxin protein. The protein-coding region of this cDNA is 73, 71, 50, and 48% identical in nucleic acid sequence to those of human macrophage chemoattractant protein (MCP) 3, MCP-1, macrophage inflammatory protein (MIP) 1 alpha, and RANTES, respectively. Analysis of genomic DNA suggested that there is a single eotaxin gene in guinea pig which is apparently conserved in mice. High constitutive levels of eotaxin mRNA expression were observed in the lung, while the intestines, stomach, spleen, liver, heart, thymus, testes, and kidney expressed lower levels. To determine if eotaxin mRNA levels are elevated during allergen-induced eosinophilic airway inflammation, ovalbumin (OVA)-sensitized guinea pigs were challenged with aerosolized antigen. Compared with the lungs from saline-challenged animals, eotaxin mRNA levels increased sixfold within 3 h and returned to baseline by 6 h. Thus, eotaxin mRNA levels are increased in response to allergen challenge during the late phase response. The identification of constitutive eotaxin mRNA expression in multiple tissues suggests that in addition to regulating airway eosinophilia, eotaxin is likely to be involved in eosinophil recruitment into other tissues as well as in baseline tissue homing. PMID:7869037

  13. Mast cell expression of the serotonin1A receptor in guinea pig and human intestine.

    PubMed

    Wang, Guo-Du; Wang, Xi-Yu; Zou, Fei; Qu, Meihua; Liu, Sumei; Fei, Guijun; Xia, Yun; Needleman, Bradley J; Mikami, Dean J; Wood, Jackie D

    2013-05-15

    Serotonin [5-hydroxytryptamine (5-HT)] is released from enterochromaffin cells in the mucosa of the small intestine. We tested a hypothesis that elevation of 5-HT in the environment of enteric mast cells might degranulate the mast cells and release mediators that become paracrine signals to the enteric nervous system, spinal afferents, and secretory glands. Western blotting, immunofluorescence, ELISA, and pharmacological analysis were used to study expression of 5-HT receptors by mast cells in the small intestine and action of 5-HT to degranulate the mast cells and release histamine in guinea pig small intestine and segments of human jejunum discarded during Roux-en-Y gastric bypass surgeries. Mast cells in human and guinea pig preparations expressed the 5-HT1A receptor. ELISA detected spontaneous release of histamine in guinea pig and human preparations. The selective 5-HT1A receptor agonist 8-hydroxy-PIPAT evoked release of histamine. A selective 5-HT1A receptor antagonist, WAY-100135, suppressed stimulation of histamine release by 5-HT or 8-hydroxy-PIPAT. Mast cell-stabilizing drugs, doxantrazole and cromolyn sodium, suppressed the release of histamine evoked by 5-HT or 8-hydroxy-PIPAT in guinea pig and human preparations. Our results support the hypothesis that serotonergic degranulation of enteric mast cells and release of preformed mediators, including histamine, are mediated by the 5-HT1A serotonergic receptor. Association of 5-HT with the pathophysiology of functional gastrointestinal disorders (e.g., irritable bowel syndrome) underlies a question of whether selective 5-HT1A receptor antagonists might have therapeutic application in disorders of this nature.

  14. Fetal guinea pig brain 15-hydroxyprostaglandin dehydrogenase: Ontogeny and effect of ethanol

    SciTech Connect

    Treissman, D.; Brien, J.F. )

    1991-03-01

    The objectives of this study were to determine the ontogeny of 15-hydroxyprostaglandin dehydrogenase (15-OH-PGDH) activity in the brain of the fetal guinea pig and to test the hypothesis that acute in vitro ethanol exposure produces concentration-dependent inhibition of fetal brain 15-OH-PGDH activity. Enzyme activity was determined in vitro by measuring the rate of oxidation of PGE2 to 15-keto-PGE2 using an optimized radiometric procedure. The study was conducted utilizing the whole brain of the fetal guinea pig at mean gestational ages of 34, 43 and 62 days (term, about 66 days) and the brain stem (pons and medulla) of the fetal guinea pig at mean gestational ages of 43 and 62 days. The direct effect of acute in vitro exposure to ethanol was assessed by incubating 15-OH-PGDH with ethanol in the concentration range of 10 to 80 mM. 15-OH-PGDH was measurable in the whole brain and brain stem, and the enzyme activity was similar for the gestational ages examined. There was no significant ethanol-induced inhibition of 15-OH-PGDH activity in the whole brain or brain stem. The data demonstrate that the whole brain and brain stem of the fetal guinea pig have the capacity to metabolize PGE2 to 15-keto-PGE2, an inactive metabolite, during the second half of gestation. The data apparently are not consistent with the hypothesis that acute in vitro exposure to ethanol directly inhibits 15-OH-PGDH activity in fetal brain.

  15. The adverse effect of commercial dentine-bonding systems on the skin of guinea pigs.

    PubMed

    Katsuno, K; Manabe, A; Kurihara, A; Itoh, K; Hisamitsu, H; Wakumoto, S; Yoshida, T

    1998-03-01

    It was widely known that 2-hydroxyethyl methacrylate (2-HEMA) can cause contact dermatitis. Commercially available dentine primers and dentine bonding agents that contain 2-HEMA are widely used. The purpose of this study was to investigate the cumulative irritation and delayed hypersensitivity caused by commercial dentine bonding systems when applied to the skin of guinea pigs. We have concluded that almost no dentine bonding systems cause cumulative irritation, but some commercially available dentine bonding systems may produce delayed hypersensitivity.

  16. Early microvascular changes in the preterm neonate: a comparative study of the human and guinea pig

    PubMed Central

    Dyson, Rebecca M.; Palliser, Hannah K.; Lakkundi, Anil; de Waal, Koert; Latter, Joanna L.; Clifton, Vicki L.; Wright, Ian M. R.

    2014-01-01

    Abstract Dysfunction of the transition from fetal to neonatal circulatory systems may be a major contributor to poor outcome following preterm birth. Evidence exists in the human for both a period of low flow between 5 and 11 h and a later period of increased flow, suggesting a hypoperfusion–reperfusion cycle over the first 24 h following birth. Little is known about the regulation of peripheral blood flow during this time. The aim of this study was to conduct a comparative study between the human and guinea pig to characterize peripheral microvascular behavior during circulatory transition. Very preterm (≤28 weeks GA), preterm (29–36 weeks GA), and term (≥37 weeks GA) human neonates underwent laser Doppler analysis of skin microvascular blood flow at 6 and 24 h from birth. Guinea pig neonates were delivered prematurely (62 day GA) or at term (68–71 day GA) and laser Doppler analysis of skin microvascular blood flow was assessed every 2 h from birth. In human preterm neonates, there is a period of high microvascular flow at 24 h after birth. No period of low flow was observed at 6 h. In preterm animals, microvascular flow increased after birth, reaching a peak at 10 h postnatal age. Blood flow then steadily decreased, returning to delivery levels by 24 h. Preterm birth was associated with higher baseline microvascular flow throughout the study period in both human and guinea pig neonates. The findings do not support a hypoperfusion–reperfusion cycle in the microcirculation during circulatory transition. The guinea pig model of preterm birth will allow further investigation of the mechanisms underlying microvascular function and dysfunction during the initial extrauterine period. PMID:25350751

  17. Frictional Properties of Hartley Guinea Pig Knees With and Without Proteolytic Disruption of the Articular Surfaces

    PubMed Central

    Teeple, Erin; Fleming, Braden C.; Mechrefe, Anthony P.; Crisco, Joseph J.; Brady, Mark F.; Jay, Gregory D.

    2007-01-01

    Summary Objective To apply a pendulum technique to detect changes in the coefficient of friction of the articular cartilage of the intact guinea pig tibiofemoral joint after proteolytic disruption. Design 22 hind limbs were obtained from eleven 3-month old Hartley Guinea pigs. 20 knees were block randomized to one of two treatment groups receiving injections of: 1) α-chymotrypsin (to disrupt the superficial layer of the articular surface) or 2) saline (sham; to control for the effects of the intra-articular injection). The legs were mounted in a pendulum where the knee served as the fulcrum. The decay in pendulum amplitude as a function of oscillation number was first recorded and the coefficient of friction of the joint was determined from these data before injection. 10 μL of either isotonic saline or 1 Unit/μL α-chymotrypsin was then injected into the intra-articular joint space and incubated for two hours. The pendulum test was repeated. Changes in the coefficient of friction between the sham and α-chymotrypsin joints were compared. One additional pair of knees was used for histological study of the effects of the injections. Results Treatment with α-chymotrypsin significantly increased the coefficient of friction of the guinea pig knee by 74% while sham treatment decreased it by 8%. Histological sections using Gomori trichrome stain verified that the lamina splendens was damaged following treatment with α-chymotrypsin and not following saline treatment. Conclusions Treatment with α-chymotrypsin induces mild cartilage surface damage and increases the coefficient of friction in the Hartley guinea pig knee. PMID:17010648

  18. Behavioral recovery induced by applied electric fields after spinal cord hemisection in guinea pig

    SciTech Connect

    Borgens, R.B.; Blight, A.R.; McGinnis, M.E.

    1987-10-16

    Applied electric fields were used to promote axonal regeneration in spinal cords of adult guinea pigs. A propriospinal intersegmental reflex (the cutaneous trunci muscle reflex) was used to test lateral tract function after hemisection of the thoracic spinal cord. An electrical field (200 microvolts per millimeter, cathode rostral) applied across the lesion led to functional recovery of the cutaneous trunci muscle reflex in 25 percent of experimental animals, whereas the functional deficit remained in control animals, which were implanted with inactive stimulators.

  19. Reflex-mediated desquamation of bronchiolar epithelium in guinea pigs exposed acutely to sulfuric acid aerosol.

    PubMed Central

    Brownstein, D. G.

    1980-01-01

    Terminal conducting airways are known to be vulnerable to direct injury by a variety of noxious aerosols. Sulfuric acid aerosol, a by-product of fossil fuel combustion, produces desquamation of terminal bronchiolar epithelium in guinea pigs that is believed to result from direct deep lung irritation, an effect separable from reflex airway constriction induced by sulfuric acid. To characterize desquamation of bronchiolar epithelium, 20 guinea pigs were exposed to 32.6 mg/cu m sulfuric acid aerosol with a mass median aerodynamic diameter of 1.0 micron for 4 hours. The guinea pigs were killed upon termination of the exposure, or 24 hours later, and airway alterations were evaluated by light and transmission electron microscopy. To test whether the development of bronchiolar epithelial desquamation is independent of reflex airway constriction, 24 guinea pigs were exposed to an identical aerosol for 4 hours after pretreating half with 5 mg/kg atropine sulfate intraperitoneally to inhibit airway constriction. Sulfuric acid produced diffuse pulmonary hyperinflation with areas of consolidation and atelectasis. Epithelial desquamation occurred in airways supplying regions of developing atelectasis and was most extensive in terminal bronchioles. Parasympathetic effector blockade with atropine eliminated epithelial desquamation. These results indicate that sulfuric acid-produced desquamation of terminal bronchiolar epithelium is not separable from reflex airway constriction and that terminal conducting airways are vulnerable not only to direct injury by noxious aerosols but also to indirect, reflex-mediated injury. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 PMID:7361847

  20. Cellular immune responses to amoebic liver abcess in the guinea-pig.

    PubMed Central

    Bray, R S; Harris, W G

    1977-01-01

    Guinea-pigs infected in the liver with the Biswas strain of Entamoeba histolytica showed no dermal hypersensitivity but showed positive lymphocyte transformation and macrophage-migration inhibition. The time sequence showed an activated response at 4 days after infection, a full response at 8 days when the liver abscesses were resolving and a waning response at 12 days when the abscesses had healed. PMID:891028

  1. Evidence for Oxidative Stress and Defective Antioxidant Response in Guinea Pigs with Tuberculosis

    PubMed Central

    Palanisamy, Gopinath S.; Kirk, Natalie M.; Ackart, David F.; Shanley, Crystal A.; Orme, Ian M.; Basaraba, Randall J.

    2011-01-01

    The development of granulomatous inflammation with caseous necrosis is an important but poorly understood manifestation of tuberculosis in humans and some animal models. In this study we measured the byproducts of oxidative stress in granulomatous lesions as well as the systemic antioxidant capacity of BCG vaccinated and non-vaccinated guinea pigs experimentally infected with Mycobacterium tuberculosis. In non-vaccinated guinea pigs, oxidative stress was evident within 2 weeks of infection as measured by a decrease in the serum total antioxidant capacity and blood glutathione levels accompanied by an increase in malondialdehyde, a byproduct of lipid peroxidation, within lesions. Despite a decrease in total and reduced blood glutathione concentrations, there was an increase in lesion glutathione by immunohistochemistry in response to localized oxidative stress. In addition there was an increase in the expression of the host transcription factor nuclear erythroid 2 p45-related factor 2 (Nrf2), which regulates several protein and non-proteins antioxidants, including glutathione. Despite the increase in cytoplasmic expression of Nrf2, immunohistochemical staining revealed a defect in Nrf2 nuclear translocation within granulomatous lesions as well as a decrease in the expression of the Nrf2-regulated antioxidant protein NQO1. Treating M. tuberculosis–infected guinea pigs with the antioxidant drug N-acetyl cysteine (NAC) partially restored blood glutathione concentrations and the serum total antioxidant capacity. Treatment with NAC also decreased spleen bacterial counts, as well as decreased the lung and spleen lesion burden and the severity of lesion necrosis. These data suggest that the progressive oxidative stress during experimental tuberculosis in guinea pigs is due in part to a defect in host antioxidant defenses, which, we show here, can be partially restored with antioxidant treatment. These data suggest that the therapeutic strategies that reduce oxidant

  2. Properties of kallikrein-containing granules isolated from the submaxillary gland of the guinea-pig.

    PubMed

    Bhoola, K D; Heap, P F

    1970-09-01

    1. Granular fractions of high purity consisting of subcellular kallikrein- and amylase-storing organelles have been isolated from homogenates of guinea-pig submaxillary gland.2. The isolated kallikrein- and amylase-containing granules closely resembled secretory granules observed in situ in serous acinar cells in intra-granular appearance, size and histochemical reaction.3. The subcellular, histochemical and ultrastructural studies indicate that the serine protease, kallikrein, is like amylase an exocrine enzyme with a functional role in saliva. PMID:5501268

  3. Autoradiographic visualization of muscarinic receptor subtypes in human and guinea pig lung

    SciTech Connect

    Mak, J.C.; Barnes, P.J. )

    1990-06-01

    Muscarinic receptor subtypes have been localized in human and guinea pig lung sections by an autoradiographic technique, using (3H)(-)quinuclidinyl benzilate (( 3H)QNB) and selective muscarinic antagonists. (3H)QNB was incubated with tissue sections for 90 min at 25 degrees C, and nonspecific binding was determined by incubating adjacent serial sections in the presence of 1 microM atropine. Binding to lung sections had the characterization expected for muscarinic receptors. Autoradiography revealed that muscarinic receptors were widely distributed in human lung, with dense labeling over submucosal glands and airway ganglia, and moderate labeling over nerves in intrapulmonary bronchi and of airway smooth muscle of large and small airways. In addition, alveolar walls were uniformly labeled. In guinea pig lung, labeling of airway smooth muscle was similar, but in contrast to human airways, epithelium was labeled but alveolar walls were not. The muscarinic receptors of human airway smooth muscle from large to small airways were entirely of the M3-subtype, whereas in guinea pig airway smooth muscle, the majority were the M3-subtype with a very small population of the M2-subtype present. In human bronchial submucosal glands, M1- and M3-subtypes appeared to coexist in the proportions of 36 and 64%, respectively. In human alveolar walls the muscarinic receptors were entirely of the M1-subtype, which is absent from the guinea pig lung. No M2-receptors were demonstrated in human lung. The localization of M1-receptors was confirmed by direct labeling with (3H)pirenzepine. With the exception of the alveolar walls in human lung, the localization of muscarinic receptor subtypes on structures in the lung is consistent with known functional studies.

  4. Myocardial KChIP2 Expression in Guinea Pig Resolves an Expanded Electrophysiologic Role.

    PubMed

    Nassal, Drew M; Wan, Xiaoping; Liu, Haiyan; Deschênes, Isabelle

    2016-01-01

    Cardiac ion channels and their respective accessory subunits are critical in maintaining proper electrical activity of the heart. Studies have indicated that the K+ channel interacting protein 2 (KChIP2), originally identified as an auxiliary subunit for the channel Kv4, a component of the transient outward K+ channel (Ito), is a Ca2+ binding protein whose regulatory function does not appear restricted to Kv4 modulation. Indeed, the guinea pig myocardium does not express Kv4, yet we show that it still maintains expression of KChIP2, suggesting roles for KChIP2 beyond this canonical auxiliary interaction with Kv4 to modulate Ito. In this study, we capitalize on the guinea pig as a system for investigating how KChIP2 influences the cardiac action potential, independent of effects otherwise attributed to Ito, given the endogenous absence of the current in this species. By performing whole cell patch clamp recordings on isolated adult guinea pig myocytes, we observe that knock down of KChIP2 significantly prolongs the cardiac action potential. This prolongation was not attributed to compromised repolarizing currents, as IKr and IKs were unchanged, but was the result of enhanced L-type Ca2+ current due to an increase in Cav1.2 protein. In addition, cells with reduced KChIP2 also displayed lowered INa from reduced Nav1.5 protein. Historically, rodent models have been used to investigate the role of KChIP2, where dramatic changes to the primary repolarizing current Ito may mask more subtle effects of KChIP2. Evaluation in the guinea pig where Ito is absent, has unveiled additional functions for KChIP2 beyond its canonical regulation of Ito, which defines KChIP2 as a master regulator of cardiac repolarization and depolarization.

  5. A small animal model study of perlite and fir bark dust on guinea pig lungs.

    PubMed

    McMichael, R F; DiPalma, J R; Blumenstein, R; Amenta, P S; Freedman, A P; Barbieri, E J

    1983-05-01

    Fir bark (Abies) and perlite (noncrystalline silicate) dusts have been reported to cause pulmonary disease in humans. Guinea pigs were exposed to either fir bark or perlite dust in a special chamber. Severe pathologic changes occurred in the lungs, consisting of lymphoid aggregated and a perivascular inflammatory response. Both dusts caused similar changes although one was vegetable (fir bark) and the other mineral (perlite). Fir bark and perlite dust appeared to be more than just nuisance dusts.

  6. C-Kit expression in the gallbladder of guinea pig with chronic calculous cholecystitis and the effect of Artemisia capillaris Thunb on interstitial cells of Cajal

    PubMed Central

    Feng, Hua; Wang, Fang; Wang, Changmiao

    2016-01-01

    Objective(s): To study the c-Kit expression in the gallbladder of cholesterol lithogenic guinea pig model and the effect of Artemisia capillaris Thunb on interstitial cells of Cajal (ICCs). Materials and Methods: A total of 45 guinea pigs were randomly assigned into three groups: the control group (guinea pigs fed a standard diet, normal group); the model group (guinea pigs fed a cholesterol gallstone-inducing diet); and the Chinese medicine group (guinea pigs fed the cholesterol gallstone-inducing diet and treated with A. capillaris through intragastric administration, therapy group). Each group had 15 guinea pigs. The gallbladders of the guinea pigs were harvested after 8 weeks. C-Kit expression was detected using an immunohistochemistry staining, real-time PCR, and Western blot analyses. The effect of A. capillaris on ICCs was evaluated by muscle strip contraction experiments. Results: C-Kit expression significantly decreased in the gallbladder of model group, but increased in the Chinese medicine group. The Contractility of guinea pig gallbladder muscle strip significantly improved in the Chinese medicine group. Conclusion: Our results indicated that A. capillaris improves gallbladder impairment by up-regulating c-Kit expression, and it also can improve the contractile response of in vitro guinea pig gallbladder muscle strips.

  7. The antigenic specificity of the humoral immune response to primary and repeated ocular infections of the guinea pig with the GPIC agent (Chlamydia psittaci).

    PubMed

    Treharne, J D; Shallal, A

    1991-01-01

    The antigenic specificity of the humoral immune response in guinea pigs to primary and repeated ocular infections with the guinea pig inclusion conjunctivitis (GPIC) chlamydial agent was analysed using microbiological, serological and Western blotting techniques. The results indicate that although there was a response to many minor polypeptide antigens, there was a marked lack of reactivity to the major outer membrane protein (MOMP), particularly following reinfection of guinea pigs. It is suggested that, lack of a good antibody response to the MOMP, may be one of the reasons why guinea pigs are susceptible to repeated ocular infections with this chlamydial agent.

  8. C-Kit expression in the gallbladder of guinea pig with chronic calculous cholecystitis and the effect of Artemisia capillaris Thunb on interstitial cells of Cajal

    PubMed Central

    Feng, Hua; Wang, Fang; Wang, Changmiao

    2016-01-01

    Objective(s): To study the c-Kit expression in the gallbladder of cholesterol lithogenic guinea pig model and the effect of Artemisia capillaris Thunb on interstitial cells of Cajal (ICCs). Materials and Methods: A total of 45 guinea pigs were randomly assigned into three groups: the control group (guinea pigs fed a standard diet, normal group); the model group (guinea pigs fed a cholesterol gallstone-inducing diet); and the Chinese medicine group (guinea pigs fed the cholesterol gallstone-inducing diet and treated with A. capillaris through intragastric administration, therapy group). Each group had 15 guinea pigs. The gallbladders of the guinea pigs were harvested after 8 weeks. C-Kit expression was detected using an immunohistochemistry staining, real-time PCR, and Western blot analyses. The effect of A. capillaris on ICCs was evaluated by muscle strip contraction experiments. Results: C-Kit expression significantly decreased in the gallbladder of model group, but increased in the Chinese medicine group. The Contractility of guinea pig gallbladder muscle strip significantly improved in the Chinese medicine group. Conclusion: Our results indicated that A. capillaris improves gallbladder impairment by up-regulating c-Kit expression, and it also can improve the contractile response of in vitro guinea pig gallbladder muscle strips. PMID:27635195

  9. Identification of 5HT/sub 2/-receptors on longitudinal muscle of the guinea pig ileum

    SciTech Connect

    Engel, G.; Hoyer, D.; Kalkman, H.O.; Wick, M.B.

    1984-01-01

    In binding experiments with the radioligands (/sup 3/H)Ketanserin (HKet) and (/sup 125/I)LSD (ILSD) 21 compounds were investigated using rat brain cortex membranes. The pK/sub D/-values of the compounds were virtually independent of the radioligand used and their rank order was consistent with classification of the binding sites as being of the 5-HT/sub 2/-type. In contrast, in the longitudinal muscle of the guinea pig ileum in the presence of 0.3 microM cinanserin, ILSD labelled sites which were quite different to those in the cortex. In a functional test antagonism of the 5HT induced contraction of the guinea-pig ileum was measured in the presence of 1 microM atropine. The pharmacological inhibition constants (IC/sub 50/-values) of 8 compounds correlated well with the dissociation constants for HKet binding in the cortex and did not correlate with the data from ILSD binding in the guinea pig ileum. It is concluded that the ileum contains postjunctional 5HT/sub 2/-receptors which mediate contraction. The nature of the ILSD binding sites in the ileum remains to be elucidated.

  10. Effects of thyroid state on respiration of perfused rat and guinea pig hearts

    SciTech Connect

    Read, L.C.; Wallace, P.G.; Berry, M.N. )

    1987-09-01

    The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na{sup 131}I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. In the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses.

  11. Anatomical study of blood supply to the cervical spinal cord in the guinea pig.

    PubMed

    Mazensky, David; Danko, Jan; Petrovova, Eva; Flesarova, Slavka; Supuka, Peter; Supukova, Anna; Luptakova, Lenka; Purzyc, Halina

    2015-06-01

    The aim of this study was to describe the arterial arrangement of the cervical spinal cord in the guinea pig. The study was carried out on 20 adult English self guinea pigs using corrosion and dissection technique. Batson's corrosion casting kit no. 17(©) was used as a casting medium. The origin of the ventral spinal artery from the left vertebral artery was found on average in 35% of the cases and from the right vertebral artery on average in 40% of the cases. The ventral spinal artery with origin from the anastomosis of two medial branches was found on average in 25% of the cases. The presence of ventral radicular branches of rami spinales entering the ventral spinal artery in the cervical region was observed in 42% of the cases on the right side and in 58% of the cases on the left side. The presence of dorsal radicular branches of rami spinales that reached the spinal cord was observed in 63% of the cases on the left side and in 37% of the cases on the right side. The number of radicular branches supplying the spinal cord is greater in guinea pig than in humans.

  12. Reduced airway hyperresponsiveness by phosphodiesterase 3 and 4 inhibitors in guinea-pigs.

    PubMed Central

    Germain, N; Boichot, E; Planquois, J M; Lagente, V

    1999-01-01

    The aim of the present study was to compare the effects of selective phosphodiesterase (PDE) 3, 4 and 5 inhibitors on antigen-induced airway hyperresponsiveness in sensitized guinea-pigs. When the sensitized guinea-pigs were orally pre-treated with the selective PDE4 inhibitor, Ro 20-1724 (30 mg/kg), and studied 48h after OA, a significant reduction (P<0.01) of the leftward shift of the dose-response curve to ACh was noted, whereas it was ineffective at the lower dose (10 mg/kg). Administration of the selective PDE3 inhibitor, milrinone (30 mg/kg) also elicited a significant reduction (P<0.01) of the airway hyperresponsiveness, whereas the PDE5 inhibitor zaprinast (30 mg/kg) was ineffective. These results show that both PDE3 and PDE4 inhibitors are able to inhibit the antigen-induced airway hyperresponsiveness in sensitized guinea-pigs and support the potential utility of selective PDE inhibitors in the treatment of asthma. PMID:10704053

  13. Metabolic disposition of acyclovir in the guinea pig, rabbit, and monkey.

    PubMed

    Good, S S; de Miranda, P

    1982-07-20

    Two guinea pigs and two rabbits were each inoculated subcutaneously with 14C-labeled acyclovir (25 mg/kg). Both species excreted the entire amount within 72 hours. The rabbits excreted all of the radioactivity in the urine while the guinea pigs excreted an average of 14.2 percent in the feces. The rabbits excreted an average of 71.0 percent of the dose as unchanged drug; 25.1 percent was excreted as 9-carboxymethoxymethylguanine (CMMG) and 3.5 percent as 8-hydroxy-9-(2-hydroxyethoxymethyl)guanine (8-hydroxyacyclovir). An average of 60.7 percent of the dose was recovered from the guinea pigs as acyclovir; 32.3 percent was excreted as CMMG and 3.1 percent as 8-hydroxyacyclovir. The two rabbits showed elimination-phase half-lives (t 1/2 beta) for plasma acyclovir of 0.8 and 2.2 hours. Mean t 1/2 beta for acyclovir in two rhesus, four patas, and four african green monkeys, each receiving acyclovir (10 mg/kg) as a bolus intravenous injection, were 1.2, 1.7, and 1.8 hours respectively. The average 48 hour urinary excretion of acyclovir, 8-hydroxyacyclovir, and CMMG in the rhesus monkey was estimated to be 21.3 percent, 15.3 percent, and 7.1 percent, respectively, of the total administered amount. The patas and african green species excreted the dose mostly as acyclovir and CMMG.

  14. Characterization of the Receptors for Mycobacterial Cord Factor in Guinea Pig

    PubMed Central

    Toyonaga, Kenji; Miyake, Yasunobu; Yamasaki, Sho

    2014-01-01

    Guinea pig is a widely used animal for research and development of tuberculosis vaccines, since its pathological disease process is similar to that present in humans. We have previously reported that two C-type lectin receptors, Mincle (macrophage inducible C-type lectin, also called Clec4e) and MCL (macrophage C-type lectin, also called Clec4d), recognize the mycobacterial cord factor, trehalose-6,6′-dimycolate (TDM). Here, we characterized the function of the guinea pig homologue of Mincle (gpMincle) and MCL (gpMCL). gpMincle directly bound to TDM and transduced an activating signal through ITAM-bearing adaptor molecule, FcRγ. Whereas, gpMCL lacked C-terminus and failed to bind to TDM. mRNA expression of gpMincle was detected in the spleen, lymph nodes and peritoneal macrophages and it was strongly up-regulated upon stimulation of zymosan and TDM. The surface expression of gpMincle was detected on activated macrophages by a newly established monoclonal antibody that also possesses a blocking activity. This antibody potently suppressed TNF production in BCG-infected macrophages. Collectively, gpMincle is the TDM receptor in the guinea pig and TDM-Mincle axis is involved in host immune responses against mycobacteria. PMID:24533147

  15. The Association of Viral Activation with Penicillin Toxicity in Guinea Pigs and Hamsters 1

    PubMed Central

    Green, Robert H.

    1974-01-01

    Penicillin toxicity in the guinea pig may be manifested in several different ways, and it is proposed that these toxic effects be categorized into three syndromes: (1) toxic syndrome, characterized by acute fatal illness; (2) hemorrhagic syndrome, characterized by delayed illness with leukopenia and thrombocytopenia, and culminating in massive visceral hemorrhages; (3) chronic syndrome, characterized by retardation of growth and alopecia, a condition somewhat resembling “runt disease.” A virus having some of the properties of a parvovirus has been isolated repeatedly from animals ill or dying of penicillin-induced disease. This finding has been construed as being activation of a latent virus by this antibiotic, but the relationship, if any, of the phenomenon of viral activation to the syndromes produced by penicillin and its frequent lethal toxicity is unknown. That a strong association exists, however, has been established. Of some 60 guinea pigs which received injections of penicillin three developed tumors and four others were found to have gallstones. A virus similar or identical to the guinea pig virus also has been isolated from hamsters dying of penicillin-induced disease. It is hypothesized that the absorption of endotoxin, resulting from the well known change in intestinal flora caused by penicillin, produces a state of immunodeficiency which regularly gives rise to activation of a latent virus, and perhaps, rarely, to the development of malignant neoplasms. PMID:4446629

  16. Use of the Albino Guinea-pig to Detect the Skin-sensitizing Ability of Chemicals

    PubMed Central

    Stevens, M. A.

    1967-01-01

    The guinea-pig has been used for over 20 years to demonstrate skin-sensitizing ability in chemical compounds. Correlation between the results of workers in this field is difficult because of the wide range of conditions under which tests for sensitizing potential have been performed. This has made difficult any attempt to compare the relative abilities of various chemical compounds to produce skin sensitization. In a routine test for skin-sensitizing potential, solutions of suspected sensitizing substance have been applied over three days to the ears of guinea-pigs, and the flanks have been challenged one week later with a range of concentrations of suspected sensitizing substance. The erythematous reaction produced 24 hours after challenge was rated and compared with that in unsensitized controls. Various alternative methods of skin testing have been compared with this ear-flank test. The ear-flank test gives good, reproducible results with many classes of chemical compound, including types of compound not previously described as giving rise to sensitization in the guinea-pig or in man, and including some compounds which are known to have carcinogenic potential. It is also demonstrated that sensitizing potential is found more frequently among aromatic (aryl) than aliphatic (alkyl) compounds. Particularly strong sensitization reactions are produced by certain aryl halides, aryl isocyanates, aryl hydrazines, N-nitroso compounds, and aromatic nitroso-compounds. An attempt is made to relate the results of animal tests to reported cases of human skin sensitization. PMID:6028714

  17. Multipotent stromal cells for autologous cell therapy approaches in the guinea pig model.

    PubMed

    Frölich, Katrin; Scherzed, Agmal; Mlynski, Robert; Technau, Antje; Hagen, Rudolf; Kleinsasser, Norbert; Radeloff, Andreas

    2011-01-01

    Multipotent stromal cells have become of increasing interest due to their potential to provide therapeutic approaches for autologous tissue repair. However, these cells are not well defined in the guinea pig, which represents an important model in hearing research. Adipose-tissue-derived stem cells (ADSC) and bone-marrow-derived stem cells (BMSC) were isolated from different donor sites, and growth curves were generated to judge the proliferation potential. Adipogenic, chondrogenic and osteogenic differentiation was induced and confirmed histologically. Finally, the capability of guinea pig ADSC to differentiate into neuron-like cells was investigated. With regard to the expansion potential, total cell number and doubling time, ADSC from the neck were the most suitable cells of the tested donor sites. Both ADSC and BMSC showed nearly identical behaviour and ability to undergo multilineage differentiation. Thus, we identified ADSC from the neck as a promising cell source for autologous cell-based approaches in hearing research using the guinea pig model. PMID:20975314

  18. Neuronal release of endogenous dopamine from corpus of guinea pig stomach.

    PubMed

    Shichijo, K; Sakurai-Yamashita, Y; Sekine, I; Taniyama, K

    1997-11-01

    Neuronal release of endogenous dopamine was identified in mucosa-free preparations (muscle layer including intramural plexus) from guinea pig stomach corpus by measuring tissue dopamine content and dopamine release and by immunohistochemical methods using a dopamine antiserum. Dopamine content in mucosa-free preparations of guinea pig gastric corpus was one-tenth of norepinephrine content. Electrical transmural stimulation of mucosa-free preparations of gastric corpus increased the release of endogenous dopamine in a frequency-dependent (3-20 Hz) manner. The stimulated release of dopamine was prevented by either removal of external Ca2+ or treatment with tetrodotoxin. Dopamine-immunopositive nerve fibers surrounding choline acetyltransferase-immunopositive ganglion cells were seen in the myenteric plexus of whole mount preparations of gastric corpus even after bilateral transection of the splanchnic nerve proximal to the junction with the vagal nerve (section of nerves between the celiac ganglion and stomach). Domperidone and sulpiride potentiated the stimulated release of acetylcholine and reversed the dopamine-induced inhibition of acetylcholine release from mucosa-free preparations. These results indicate that dopamine is physiologically released from neurons and from possible dopaminergic nerve terminals and regulates cholinergic neuronal activity in the corpus of guinea pig stomach. PMID:9374701

  19. Captain America, Tuskegee, Belmont, and Righteous Guinea Pigs: Considering Scientific Ethics through Official and Subaltern Perspectives

    NASA Astrophysics Data System (ADS)

    Weinstein, Matthew

    2008-09-01

    With an eye towards a potential scientific ethics curriculum, this paper examines four contrasting discourses regarding the ethics of using human subjects in science. The first two represent official statements regarding ethics. These include the U.S.’s National Science Education Standards, that identify ethics with a professional code, and the Belmont Report, that conceptualizes ethics in three principles to guide research oversight boards. Contrasting this view of ethics as decorum and practice in line with a priori principles is the conception of ethics from unofficial sources representing populations who have been human subjects. The first counter-discourse examined comes from Guinea Pig Zero, an underground magazine for professional human subjects. Here ethics emerges as a question of politics over principle. The good behavior of the doctors and researchers is an effect of the politics and agency of the communities that supply science with subjects. The second counter-discourse is a comic book called Truth, which tells the story of Black soldiers who were used as guinea pigs in World War II. Ethics is both more political and more uncertain in this narrative. Science is portrayed as complicit with the racism of NAZI Germany; at the same time, and in contrast to the professional guinea pigs, neither agency nor politics are presented as effective tools for forcing the ethical conduct of the scientific establishment. The conclusion examines the value of presenting all of these views of scientific ethics in science education.

  20. Endogenous leukotriene D4 formation during anaphylactic shock in the guinea pig.

    PubMed Central

    Keppler, A; Orning, L; Bernström, K; Hammarström, S

    1987-01-01

    Experiments on the metabolism and excretion of i.v. administered selectively labeled [3H8]leukotriene C4 in bile duct-cannulated guinea pigs indicated predominantly biliary excretion of tritium. The major leukotriene metabolite in bile was identified as leukotriene D4. By monitoring leukotriene excretion radioimmunochromatographically, it was shown that guinea pigs suffering from anaphylactic shock produce leukotriene D4 endogenously. Immunological challenge of animals sensitized to ovalbumin was accompanied by an increase of biliary leukotriene D4 concentrations from 10 +/- 1 to 86 +/- 10 nM (mean +/- SEM, n = 5, P less than 0.001). When considering that bile flow was decreased to about half after challenge, the excretion rate of leukotriene D4 in bile increased from 0.88 +/- 0.16 before to 3.18 +/- 0.38 pmol X min-1 X kg-1 after challenge (mean +/- SEM, n = 5, P less than 0.002). It is concluded that systemic anaphylaxis in the guinea pig is associated with endogenous generation of leukotriene C4 (up to 1 nmol/kg during a 30-min period after the challenge. PMID:3039514

  1. Layer I as a putative neurogenic niche in young adult guinea pig cerebrum.

    PubMed

    Xiong, Kun; Cai, Yan; Zhang, Xue-Mei; Huang, Ju-Fang; Liu, Zhong-Yu; Fu, Guang-Ming; Feng, Jia-Chun; Clough, Richard W; Patrylo, Peter R; Luo, Xue-Gang; Hu, Chun-Hong; Yan, Xiao-Xin

    2010-10-01

    A considerable number of cells expressing typical immature neuronal markers including doublecortin (DCX+) are present around layer II in the cerebral cortex of young and adult guinea pigs and other larger mammals, and their origin and biological implication await further characterization. We show here in young adult guinea pigs that these DCX+ cells are accompanied by in situ cell division around the superficial cortical layers mostly in layer I, but they co-express proliferating cell nuclear antigen (PCNA) and an early neuronal fate determining factor, PAX6. A small number of these DCX+ cells also colocalize with BrdU following administration of this mitotic indicator. Cranial X-ray irradiation causes a decline of DCX+ cells around layer II, and novel environmental exploration induces c-Fos expression among these cells in several neocortical areas. Together, these data are compatible with a notion that DCX+ cortical neurons around layer II might derive from proliferable neuronal precursors around layer I in young adult guinea pig cerebrum, and that these cells might be modulated by experience under physiological conditions.

  2. The guinea pig as a model for predicting photoallergic contact dermatitis.

    PubMed

    Jordan, W P

    1982-03-01

    This report describes modifications in the techniques used for both the induction and elicitation of photoallergic contact dermatitis (PACD) in the guinea pig. These changes have improved the reliability of this animal as the model of choice for screening chemicals or products for their tendency to produce PACD. The induction period consists of 15 exposures of the test substance to shoulder skin that has been abraded with a nylon brush rotating at 13,000 rpm. One hour later, the test site is irradiated with broadband UVA from a source having some irradiance below 320 nm (UVA/b). The animals receive 450 J/cm2 of UVA during the three-week induction period. The elicitation (challenge) test is repeated for two consecutive days. Each day, the test material, if a liquid, is applied to two sites every 30 to 60 min for 6 h; then one of the sites receives 20 J/cm2 of UVA. These photo-induction and photo-induction and photo-elicitation procedures have demonstrated that low-level concentrations (0.25% range) of 6-methyl coumarin or musk ambrette will both induce and elicit PACD in the guinea pig. This report adds more evidence that the induction of PACD in the guinea pig is dependent on broadband UVA.

  3. A novel behavioural approach to detecting tinnitus in the guinea pig.

    PubMed

    Berger, Joel I; Coomber, Ben; Shackleton, Trevor M; Palmer, Alan R; Wallace, Mark N

    2013-03-15

    Tinnitus, the perception of sound in the absence of an external stimulus, is a particularly challenging condition to demonstrate in animals. In any animal model, objective confirmation of tinnitus is essential before we can study the neural changes that produce it. A gap detection method, based on prepulse inhibition of the whole-body startle reflex, is often used as a behavioural test for tinnitus in rodents. However, in the guinea pig the whole-body startle reflex is subject to rapid habituation and hence is not an ideal behavioural measure. By contrast, in this species the Preyer or pinna reflex is a very reliable indicator of the startle response and is much less subject to habituation. We have developed a novel adaptation of the gap detection paradigm, which uses the Preyer reflex to measure the startle response, rather than whole-body movement. Using this method, we have demonstrated changes in gap detection, in guinea pigs where tinnitus had been induced by the administration of a high dose of salicylate. Our data indicate that the Preyer reflex gap detection method is a reliable test for tinnitus in guinea pigs. PMID:23291084

  4. Treatment outcome of Paederus dermatitis due to rove beetles (Coleoptera: Staphylinidae) on guinea pigs.

    PubMed

    Fakoorziba, M R; Eghbal, F; Azizi, K; Moemenbellah-Fard, M D

    2011-08-01

    Linear dermatitis (or dermatitis linearis, DL) is a skin blistering inflammatory lesion caused by exposure to the pederin toxin from rove beetles. Although it is prevalent in many countries of the Middle East region, this is not a notifiable disease. In recent years, a number of clinical symptoms outbreaks of DL has been reported from a few neighboring countries of Iran, but no report of experimental treatment among small laboratory rodents is known. This is a prerequisite to ascertain the nature of the best treatment strategy in cases of infestation with these beetles, as it occurs among local settlers during hot seasons in certain parts of the southern Iranian province of Fars. Live Paederus beetles were collected, identified to species level, sexed apart and partly processed to obtain their hemolymph toxin pederin in ethanol for dermal application on guinea pigs. Two Paederus species were found. Paederus ilsae (Bernhauer) (Coleoptera: Staphylinidae) was more abundant than P. iliensis (Coiffait). Recovery from DL due to live P. ilsae beetles was quicker and less complex than that of pederin in ethanol on guinea pigs. The application of potassium permanganate with calamine to heal DL was also more effective than fluocinolone treatment. This topical corticosteroid is thus considered less able to avert the cytotoxic action of pederin on the skin of guinea pigs than the antipruritic and cleansing agents. It seems likely that fluocinolone has certain effects which delays the recovery period for the treated skin.

  5. Prostaglandins in the perilymph of guinea pig with type II collagen induced ear diseases

    SciTech Connect

    Takeda, T.; Chiang, T.; Kitano, H.; Sudo, N.; Kim, S.Y.; Ha, S.; Woo, V.; Wolf, B.; Floyd, R.; Yoo, T.J.

    1986-03-01

    The authors have studied the prostaglandins (PGs) in the perilymph from guinea pig with type II collagen induced autoimmune ear disease. Hartly guinea pigs were immunized with type II collagen in CFA and auditory brain stem responses (ABR) were measured at 2, 3, 4, and 6 months after initial immunization perilymph was obtained and the levels of PGE2 and 6 keto-PGFl..cap alpha.. were measured by radioimmunoassays. Temporal bones were examined for the histopathologic changes. Immunized guinea pigs showed the evidence of hearing loss by ABR. The temporal bones showed the following changes: spiral ganglia degeneration, mild to moderate degree of degeneration in organ of Corti, infrequent very mild endolymphatic hydrops and labrynthitis. The perilymph from immunized animals contained about 5 times more PGE2 and about 3 times more 6 keto-PGFl..cap alpha.. than control animals. However, between these two groups, there was no difference in the CSF and sera levels of PGE2 and 6 keto-PGFl..cap alpha... Thus, this study suggests that these inflammatory mediators might be involved in the pathogenesis of collagen induced autoimmune inner ear disease.

  6. Absence of progesterone effects on chlamydial genital infection in female guinea pigs.

    PubMed

    Pasley, J N; Rank, R G; Hough, A J; Cohen, C; Barron, A L

    1985-01-01

    The effect of progesterone alone and in combination with estradiol was investigated in ovariectomized and gonadally intact female guinea pigs infected with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). The course of the infection, as determined by the percentage of cells with GPIC (chlamydia) inclusions in Giemsa-stained vaginal scrapings, was not affected in animals receiving 5.0 mg of progesterone daily. Progesterone had no influence on the enhancement of infection by estradiol. In comparison with sesame oil-treated controls, infection was prolonged by four to six days (P less than .05) in animals receiving a combination of 5.0 mg of progesterone plus 1.0 microgram of estradiol or 1.0 microgram of estradiol alone each day. In ovariectomized animals, estradiol delayed the appearance of IgA antibody in genital secretions, whereas progesterone alone had no effect. Guinea pigs treated with estradiol or progesterone plus estradiol manifested an acute endometritis not observed in animals treated with progesterone alone or in controls receiving sesame oil. Although cervical ectopy, analogous to that seen in women with high levels of progesterone, was identified by histopathology in animals treated with progesterone, no enhancement of the chlamydial infection was observed.

  7. The Guinea Pig Sensitized by House Dust Mite: A Model of Experimental Cough Studies.

    PubMed

    Buday, T; Gavliakova, S; Mokry, J; Medvedova, I; Kavalcikova-Bogdanova, N; Plevkova, J

    2016-01-01

    The guinea pig sensitized by ovalbumin is the most widely used model to study cough experimentally, as the neurophysiology of the vagus nerve in the guinea pig is closest to humans. Nonetheless, the choice of the antigen remains questionable, which influences the translation of results into clinical medicine. The present study seeks to develop an alternative model of cough study using house dust mite sensitization (HDM). Thirty guinea pigs were divided into the HDM group, ovalbumin (OVA) group, and control group based on their cough response to 0.4 M citric acid. In the HDM group animals were sensitized by 0.25 %HDM aerosol, which they inhaled for 5 min over 5 days, followed by inhalation of 0.5 %HDM in the same protocol. Sensitization was confirmed by a skin test. Symptoms of allergic rhinitis were induced by intranasal application of 15 μl 0.5 %HDM and cough challenges with citric acid were performed. Airway resistance was measured in vivo by Pennock's method. We found that both HDM and OVA-sensitized groups showed a significantly enhanced nasal reactivity and cough response compared with controls. The airway resistance data did not show significant differences. We conclude that the HDM cough model replicates functional aspects of the OVA model, which may make it an alternative to the latter. However, the superiority of the HDM model for experimental cough studies remains to be further explored. PMID:26987338

  8. Comparison of effects of glass fibre and glass powder on guinea-pig lungs

    PubMed Central

    Botham, Susan K.; Holt, P. F.

    1973-01-01

    Botham, Susan K., and Holt, P. F. (1973).British Journal of Industrial Medicine,30, 232-236. Comparison of effects of glass fibre and glass powder on guinea-pig lungs. Following 24 hours inhalation by guinea-pigs of powdered glass dust, the pulmonary effects over the succeeding month differed from those previously observed to follow inhalation of glass fibre in that (1) fewer erythrocytes escaped from the capillaries, (2) very few giant cells were produced, (3) erythrocytes and intracellular glass particles were cleared more readily because junctions between respiratory and terminal bronchioles were not blocked by giant cells, (4) intracellular granules containing Perls-positive material did not appreciably increase in number or intensity of staining during the month, and (5) particles were not coated with Perls-positive material during the time that pseudo-asbestos bodies would be formed from glass fibres. The difference between the effects of chemically similar glass powder and fibre during a month in a guinea-pig lung is considered to be due to the morphology of the inhaled particle. Images PMID:4124978

  9. Assessment of vaccine testing at three laboratories using the guinea pig model of tuberculosis.

    PubMed

    Grover, Ajay; Troudt, Jolynn; Arnett, Kimberly; Izzo, Linda; Lucas, Megan; Strain, Katie; McFarland, Christine; Hall, Yper; McMurray, David; Williams, Ann; Dobos, Karen; Izzo, Angelo

    2012-01-01

    The guinea pig model of tuberculosis is used extensively in different locations to assess the efficacy of novel tuberculosis vaccines during pre-clinical development. Two key assays are used to measure protection against virulent challenge: a 30 day post-infection assessment of mycobacterial burden and long-term post-infection survival and pathology analysis. To determine the consistency and robustness of the guinea pig model for testing vaccines, a comparative assessment between three sites that are currently involved in testing tuberculosis vaccines from external providers was performed. Each site was asked to test two "subunit" type vaccines in their routine animal model as if testing vaccines from a provider. All sites performed a 30 day study, and one site also performed a long-term survival/pathology study. Despite some differences in experimental approach between the sites, such as the origin of the Mycobacterium tuberculosis strain and the type of aerosol exposure device used to infect the animals and the source of the guinea pigs, the data obtained between sites were consistent in regard to the ability of each "vaccine" tested to reduce the mycobacterial burden. The observations also showed that there was good concurrence between the results of short-term and long-term studies. This validation exercise means that efficacy data can be compared between sites.

  10. [The electron microscopic findings of helicoid bacteria lining the mucosa of the cecum in guinea pigs].

    PubMed

    Raygoza-Anaya, M; Bondarenko, V M; Mora-Galindo, H; González-Robles, A

    1991-08-01

    This study has revealed that helical bacteria inhabiting the mucous membrane of the cecum of guinea pigs are localized in the parietal zone of the epithelium and can be detected as biological film consisting of many microcolonies. Helical bacteria are attached to the epithelium by insertion of one of the ends of an eukaryotic cell into the space between microvilli without damaging epithelial cells and their microvilli. Helical bacteria have been found to use the "anchor" type of attachment to the epithelium, which ensures the stability of their high population level in the biotope. These microorganisms appear on the mucous membrane of the epithelium, starting from day 15 of the life of guinea pigs. At the period of the transition of suckling guinea pigs to independent nourishment the population of helical bacteria is partially suppressed due to the appearance of bacillary and filamentous forms of bacteria, but later, after the adaptation of the animals to their diet, helical bacteria become normal resident microflora which forms biofilm covering large areas of the mucous membrane and the entrances of crypts of Lieberkühn.

  11. Effects of novel bile salts on cholesterol metabolism in rats and guinea-pigs.

    PubMed

    Fears, R; Brown, R; Ferres, H; Grenier, F; Tyrrell, A W

    1990-11-01

    Novel bile salts (quaternary ammonium conjugates) inhibited cholic acid binding and transport in everted ileal sacs in vitro. The cationic piperazine conjugate of lithocholic acid (di-iodide salt, compound 8, BRL 39924A) appeared most active, inhibiting binding by 29% and transport by 59% in guinea-pig ileum (200 microM). BRL 39924A also inhibited taurocholate uptake into guinea-pig ileal sacs and cholate uptake into rat ileal sacs and was selected for further study in vivo. In hyperlipidaemic rats, BRL 39924A significantly raised cholesterol 7 alpha-hydroxylase activity and decreased hepatic accumulation of exogenous cholic acid. HDL cholesterol concentration in the serum increased and the level of VLDL plus LDL cholesterol decreased. In hyperlipidaemic guinea-pigs. BRL 39924A lowered serum total cholesterol and triglyceride levels. Although metabolic changes were less than those achieved with the bile acid sequestrant, cholestyramine, the doses of BRL 39924A used were much lower (100-500 mg/kg body wt). Selective inhibition of receptor mediated bile acid uptake may be associated with local side-effects but these novel bile salts are useful pharmacological tools to examine the effects of receptor blockade on lipoprotein metabolism. PMID:2242032

  12. Neuronal release of endogenous dopamine from corpus of guinea pig stomach.

    PubMed

    Shichijo, K; Sakurai-Yamashita, Y; Sekine, I; Taniyama, K

    1997-11-01

    Neuronal release of endogenous dopamine was identified in mucosa-free preparations (muscle layer including intramural plexus) from guinea pig stomach corpus by measuring tissue dopamine content and dopamine release and by immunohistochemical methods using a dopamine antiserum. Dopamine content in mucosa-free preparations of guinea pig gastric corpus was one-tenth of norepinephrine content. Electrical transmural stimulation of mucosa-free preparations of gastric corpus increased the release of endogenous dopamine in a frequency-dependent (3-20 Hz) manner. The stimulated release of dopamine was prevented by either removal of external Ca2+ or treatment with tetrodotoxin. Dopamine-immunopositive nerve fibers surrounding choline acetyltransferase-immunopositive ganglion cells were seen in the myenteric plexus of whole mount preparations of gastric corpus even after bilateral transection of the splanchnic nerve proximal to the junction with the vagal nerve (section of nerves between the celiac ganglion and stomach). Domperidone and sulpiride potentiated the stimulated release of acetylcholine and reversed the dopamine-induced inhibition of acetylcholine release from mucosa-free preparations. These results indicate that dopamine is physiologically released from neurons and from possible dopaminergic nerve terminals and regulates cholinergic neuronal activity in the corpus of guinea pig stomach.

  13. Pulmonary dendritic cell distribution and prevalence in guinea pig airways: effect of ovalbumin sensitization and challenge.

    PubMed

    Lawrence, T E; Millecchia, L L; Frazer, D G; Fedan, J S

    1997-08-01

    We characterized the localization and prevalence of dendritic cells (DC) in guinea pig airways before and after s.c. sensitization and aerosol challenge with ovalbumin (OVA). DC, eosinophils, macrophages, T cells and B cells in lung and trachea were identified and quantified in frozen sections using monoclonal antibodies and computer-assisted image analysis. Airway reactivity of conscious animals to inhaled methacholine was examined. In unsensitized animals, DC were localized primarily within the lamina propria of the trachea and bronchi, in the submucosa of the trachea and in the adventitia of the bronchi. In contrast to reported studies on rats, few DC were noted in the epithelium. After OVA challenge, sensitized animals demonstrated an early obstructive response and a late-phase response that was well developed by 18 hr. Challenge with OVA increased DC prevalence in the lamina propria and submucosa of the trachea and in the lamina propria and adventitia of the bronchi. There was widespread eosinophilia throughout the airways, but no changes in B cells or T cells were evident. Macrophages were increased in the epithelium of both OVA-treated and saline-treated animals. At 18 hr after challenge, sensitized guinea pigs but not saline-treated controls were hyperreactive to inhaled methacholine. Except for macrophages, none of these effects were observed after saline treatment. Our findings indicate that inflammation in the airways of OVA-sensitized guinea pigs involves infiltration of DC, which is seen at the time animals are hyperreactive to inhaled methacholine. PMID:9262368

  14. The effect of subchronic exposure to the rubber vulcanization fumes on guinea pig lungs.

    PubMed

    Rydzyński, K; Domańska, A; Czerczak, S; Krysiak, B

    1990-01-01

    The influence of 28 days' inhalatory exposure to rubber vulcanization fumes at a concentration of 100 mg/m3 on guinea pigs' lung morphology was investigated. Focal infiltrations of pulmonary parenchyma with lymphocytes, neutrophilic and eosinophilic granulocytes and macrophages were observed. Lymphatic tissue concentrations having the typical appearance of solitary lymphatic nodules were also seen. The use of the double sequential Alcian blue/safranin O staining method for the identification of the mast cells [MCs] revealed that only Alcian-blue-positive MCs were observed, regardless of the region of the lungs examined, both in control and exposed guinea pigs. No safranin-0-positive MCs were seen. However, the MCs number increased from 1934 +/- 91 cells/mm3 tissue in controls to a statistically significant (p less than 0.05) 2486 +/- 89 cells/mm3 tissue in exposed guinea pig lungs. It was accompanied by histamine content increase from 1.50 +/- 0.06 micrograms/g wet tissue weight and 2.45 +/- 0.18 micrograms/g wet tissue weight, respectively. The distribution of the lung MCs varied, showing a statistically significant (p less than 0.05) increase in their number in the intraalveolar septa: from 957 +/- 53 to 1369 +/- 74 cells/mm3 tissue and in the peribronchial and peribronchiolar spaces: from 204 +/- 36 to 359 +/- 42 cells/mm3 tissue.

  15. Effect of intratympanic application of efinaconazole 10 % solution in the guinea pig.

    PubMed

    Arakawa, Kazuya; Nomura, Kazuhiro; Oshima, Hidetoshi; Honkura, Yohei; Ikeda, Ryoukichi; Hidaka, Hiroshi; Kawase, Tetsuaki; Katori, Yukio

    2016-05-01

    Efinaconazole 10 % solution is a new triazole antifungal agent developed for the topical treatment of fungal infections of the nails. The current study examined the effect of intratympanic application of efinaconazole 10 % solution in the guinea pig ear. Sixteen male Hartley guinea pigs (weight 501-620 g) were divided into 3 groups to be treated with efinaconazole 10 % solution, gentamicin (50 mg/mL), or saline solution. Topical solutions of 0.2 mL were applied through a small hole made at the tympanic bulla once daily for 7 consecutive days. Post-intervention auditory brainstem responses were obtained 7 days after the last treatment. The extent of middle ear damage and hair cell loss was investigated. The efinaconazole- and gentamicin-treated groups showed severe deterioration in auditory brainstem response threshold. Middle ear examination revealed extensive changes in the efinaconazole-treated group and medium changes in the gentamicin-treated group. Hair cells were preserved in the efinaconazole- and saline-treated groups, but severe damage was seen in the gentamicin group. In conclusion, efinaconazole 10 % solution applied intratympanically to the guinea pig middle ear caused significant middle ear inflammation and hearing impairment.

  16. Lethal Gram-Negative Bacterial Superinfection in Guinea Pigs Given Bacitracin

    PubMed Central

    Farrar, W. Edmund; Kent, Thomas H.; Elliott, Van B.

    1966-01-01

    Farrar, W. Edmund, Jr. (Walter Reed Army Institute of Research, Washington, D.C.), Thomas H. Kent, and Van B. Elliott. Lethal gram-negative bacterial superinfection in guinea pigs given bacitracin. J. Bacteriol. 92:496–501. 1966.—Oral administration of a single dose of bacitracin (either 2,000 or 10,000 units) was lethal to more than 80% of guinea pigs. Within the first 12 hr, there was a 2,000-fold fall in the number of gram-positive organisms in the cecum. An increase in the number of coliform bacteria in the cecum was demonstrable within 6 hr, and, by 48 hr, these organisms had increased from the normal level of less than 100 per gram to approximately 1 billion per gram. The changes in intestinal bacterial flora were associated with development of a severe cecitis, mild ileitis, and acute regional lymphadenitis. Bacteremia, primarily due to coliform bacteria, was demonstrated in approximately 40% of the animals killed between 72 and 96 hr after administration of bacitracin. Development of this disease syndrome was suppressed by the administration of neomycin and polymyxin B, nonabsorbable antibiotics effective against coliform bacteria. The lethal disease produced by bacitracin in the guinea pig is similar to that produced by penicillin. Images PMID:16562140

  17. Leucocyte kinesis in blood, bronchoalveoli and nasal cavities during late asthmatic responses in guinea-pigs.

    PubMed

    Nabe, T; Shinoda, N; Yamashita, K; Yamamura, H; Kohno, S

    1998-03-01

    Recently, we reported a reproducible model of asthma in guinea-pigs in vivo, which developed a late asthmatic response (LAR) as well as an early response. In this study, time-related changes in the occurrence of the LAR and leucocyte kinesis were assessed. Furthermore, the state of the activation of eosinophils that migrated into the lower airways was characterized in vitro. Guinea-pigs were alternately sensitized/challenged by inhalation with aerosolized ovalbumin adsorbed on aluminium hydroxide and ovalbumin alone, once every 2 weeks. At defined times before and after the fifth challenge, airway resistance was measured, blood was drawn and bronchoalveolar lavage (BAL) and nasal cavity lavage (NCL) were performed. Superoxide anion (.O2-) production of eosinophils was measured with cytochrome c. Occurrence of LAR and considerable increases in circulating eosinophils coincided with each other 5-7 h after the challenge. After 7 h, eosinophil infiltrations into bronchoalveolar spaces were observed. The capacity of eosinophils from the sensitized animals to produce .O2- was higher than those from the non-sensitized ones, when eosinophils were stimulated by platelet-activating factor. Although an increased number of eosinophils in the NCL fluid was observed, it was much less than that in the BAL fluid. Thus, it has been concluded that eosinophilia in the blood and the lung may participate in the occurrence of the late asthmatic response, which is thought to be preferentially evoked in the lower airways in guinea-pigs in vivo.

  18. Predominant involvement of the cerebellum in guinea pigs infected with bovine spongiform encephalopathy (BSE).

    PubMed

    Furuoka, H; Horiuchi, M; Yamakawa, Y; Sata, T

    2011-05-01

    This study reports the experimental transmission of bovine spongiform encephalopathy (BSE) to guinea pigs and describes the cerebellar lesions in these animals. Guinea pigs were inoculated intracerebrally with 10% brain homogenates from BSE-affected cattle. These animals were designated as the first passage. Second and third passages were subsequently performed. All guinea pigs developed infection at each passage. The mean incubation period of the first passage was 370 days post-infection (dpi) and this decreased to 307 dpi and 309 dpi for the second and third passages, respectively. Mild to severe spongiform degeneration and gliosis were observed in the cerebral cortex, thalamus and brainstem. In addition, the affected animals had marked pathological changes in the cerebellum characterized by severe cortical atrophy associated with Bergmann radial gliosis of the molecular layer and reduction in the width of the granular cell layer. Immunohistochemically, intense PrP(Sc) deposition and scattered plaque-like deposits were observed in the molecular and granular cell layers. Cerebellar lesions associated with severe atrophy of the cortex have not been reported in animal prion diseases, including in the experimental transmission of PrP(Sc) to small rodents. These lesions were similar to the lesions of human kuru or the VV2 variant of sporadic Creutzfeldt-Jakob disease, although typical kuru plaques or florid plaques were not observed in the affected animals.

  19. Effects of increased dietary cholesterol with carbohydrate restriction on hepatic lipid metabolism in Guinea pigs.

    PubMed

    deOgburn, Ryan; Leite, Jose O; Ratliff, Joseph; Volek, Jeff S; McGrane, Mary M; Fernandez, Maria Luz

    2012-04-01

    Excessive lipid accumulation within hepatocytes, or hepatic steatosis, is the pathognominic feature of nonalcoholic fatty liver disease (NAFLD), a disease associated with insulin resistance and obesity. Low-carbohydrate diets (LCD) improve these conditions and were implemented in this study to potentially attenuate hepatic steatosis in hypercholesterolemic guinea pigs. Male guinea pigs (n = 10 per group) were randomly assigned to consume high cholesterol (0.25 g/100 g) in either a LCD or a high-carbohydrate diet (HCD) for 12 wk. As compared with HCD, plasma LDL cholesterol was lower and plasma triglycerides were higher in animals fed the LCD diet, with no differences in plasma free fatty acids or glucose. The most prominent finding was a 40% increase in liver weight in guinea pigs fed the LCD diet despite no differences in hepatic cholesterol or triglycerides between the LCD and the HCD groups. Regardless of diet, all livers had severe hepatic steatosis on histologic examination. Regression analysis suggested that liver weight was independent of body weight and liver mass was independent of hepatic lipid content. LCD livers had more proliferating hepatocytes than did HCD livers, suggesting that in the context of cholesterol-induced hepatic steatosis, dietary carbohydrate restriction enhances liver cell proliferation.

  20. Effects of Increased Dietary Cholesterol with Carbohydrate Restriction on Hepatic Lipid Metabolism in Guinea Pigs

    PubMed Central

    deOgburn, Ryan; Leite, Jose O; Ratliff, Joseph; Volek, Jeff S; McGrane, Mary M; Fernandez, Maria Luz

    2012-01-01

    Excessive lipid accumulation within hepatocytes, or hepatic steatosis, is the pathognominic feature of nonalcoholic fatty liver disease (NAFLD), a disease associated with insulin resistance and obesity. Low-carbohydrate diets (LCD) improve these conditions and were implemented in this study to potentially attenuate hepatic steatosis in hypercholesterolemic guinea pigs. Male guinea pigs (n = 10 per group) were randomly assigned to consume high cholesterol (0.25 g/100 g) in either a LCD or a high-carbohydrate diet (HCD) for 12 wk. As compared with HCD, plasma LDL cholesterol was lower and plasma triglycerides were higher in animals fed the LCD diet, with no differences in plasma free fatty acids or glucose. The most prominent finding was a 40% increase in liver weight in guinea pigs fed the LCD diet despite no differences in hepatic cholesterol or triglycerides between the LCD and the HCD groups. Regardless of diet, all livers had severe hepatic steatosis on histologic examination. Regression analysis suggested that liver weight was independent of body weight and liver mass was independent of hepatic lipid content. LCD livers had more proliferating hepatocytes than did HCD livers, suggesting that in the context of cholesterol-induced hepatic steatosis, dietary carbohydrate restriction enhances liver cell proliferation. PMID:22546916

  1. Analysis of anabolic steroids in hair: time courses in guinea pigs.

    PubMed

    Shen, Min; Xiang, Ping; Yan, Hui; Shen, Baohua; Wang, Mengye

    2009-09-01

    Sensitive, specific, and reproducible methods for the quantitative determination of eight anabolic steroids in guinea pig hair have been developed using LC/MS/MS and GC/MS/MS. Methyltestosterone, stanozolol, methandienone, nandrolone, trenbolone, boldenone, methenolone and DHEA were administered intraperitoneally in guinea pigs. After the first injection, black hair segments were collected on shaved areas of skin. The analysis of these segments revealed the distribution of anabolic steroids in the guinea pig hair. The major components in hair are the parent anabolic steroids. The time courses of the concentrations of the steroids in hair (except methenolone, which does not deposit in hair) demonstrated that the peak concentrations were reached on days 2-4, except stanozolol, which peaked on day 10 after administration. The concentrations in hair appeared to be related to the physicochemical properties of the drug compound and to the dosage. These studies on the distribution of drugs in the hair shaft and on the time course of their concentration changes provide information relevant to the optimal time and method of collecting hair samples. Such studies also provide basic data that will be useful in the application of hair analysis in the control of doping and in the interpretation of results.

  2. A unique localization of mechanoreceptors in the periodontal tissue of guinea pig teeth.

    PubMed

    Jayawardena, Chantha K; Takahashi, Nobuyuki; Takano, Yoshiro

    2002-08-01

    This study describes the unique distribution of Ruffini endings (RE) in the periodontal tissues of the guinea pig teeth with special references to their presence in the enamel-related aspects of the continuously growing incisors and molars. In guinea pig incisors, immunohistochemistry for PGP 9.5 and glia specific S-100 protein revealed a condensed distribution of well-developed RE in the bone-related part of the lingual periodontal ligament as has been reported in many other rodents. In most cases, some RE-like nerve elements characterized by dendritic ramification and rounded terminal Schwann cells were found to be located in the labial, enamel-related regions, where no periodontal ligament-like fiber arrangement was established. In the molar periodontal ligament, well-developed RE-like nerve elements were also distributed in the enamel-related part, but in intimate relation to thick periodontal fiber bundles inserted in the cementum pearls grown on the enamel surface. In some cases, few RE were located in the apical region of the alveolar socket, where no periodontal fiber bundles could be identified. Our data provide the first morphological evidence of the presence of RE-like nerve elements in the enamel-related, fibrous connective tissue of continuously erupting rodent incisors. These data indicate that RE in guinea pig periodontal tissues have variable spatial correlation to the surrounding fibers, implicating their diverse mechanoreceptive properties depending on the anatomical location. PMID:12389662

  3. Molecular cloning and functional expression of a sodium bicarbonate cotransporter from guinea-pig parotid glands.

    PubMed

    Koo, Na-Youn; Li, Jingchao; Hwang, Sung Min; Choi, Se-Young; Lee, Sung Joong; Oh, Seog-Bae; Kim, Joong-Soo; Lee, Jong Heun; Park, Kyungpyo

    2006-04-21

    We recently found that the concentration of HCO3- in guinea-pig saliva is very similar to that of human saliva; however, the entity that regulates HCO3- transport has not yet been fully characterized. In order to investigate the mechanism of HCO3- transport, we identified, cloned, and characterized a sodium bicarbonate (Na(+)/HCO3- cotransporter found in guinea-pig parotid glands (gpNBC1). The gpNBC1 gene encodes a 1079-amino acid protein that has 95% and 96% homology with human and mouse parotid NBC1, respectively. Oocytes expressing gpNBC1 were exposed to HCO3- or Na(+)-free solutions, which resulted in a marked change in membrane potentials (V(m)), suggesting that gpNBC1 is electrogenic. Likewise, a gpNBC1-mediated pH recovery was observed in gpNBC1 transfected human hepatoma cells; however, in the presence of 4, 4-diisothiocyanostilbene-2,2-disulfonic acid, a specific NBC1 inhibitor, such changes in V(m) and pH(i) were not observed. Together, the data show that the cloned guinea-pig gene is a functional, as well as sequence homologue of human NBC1. PMID:16513089

  4. Histochemical localization of cholinesterase activity in the dental epithelium of guinea pig teeth.

    PubMed

    Jayawardena, C K; Takano, Y

    2004-07-01

    Cholinesterase is known for its remarkable diversity in distribution and function. An association of this enzyme with proliferative and morpho-differentiating tissues has been reported in several species. Here we report on the first evidence of the presence of cholinesterase in the enamel organ of continuously erupting incisors and molars of the guinea pig. Frozen sections of the incisors and molars of the guinea pig were incubated for histochemical demonstration of cholinesterase activity by means of the thiocholine method as described by Karnovsky and Root. The cholinesterase activity was observed in several types of cells of the dental epithelium; cells forming the basal portion of the enamel organ, outer enamel epithelium and maturation stage ameloblasts of both the incisors and molars. In the crown analogue side, the outer enamel epithelial cells gained strong reactions for cholinesterase and maintained the reaction throughout the secretory and maturation stages of amelogenesis. In contrast, cholinesterase reactions were lacking in the inner enamel epithelium, pre-ameloblasts, and secretory ameloblasts. In the early stage of enamel maturation, ameloblasts began to show positive reactions for cholinesterase, which was upregulated in the incisal direction. Although both tooth types showed similar reactive patterns for cholinesterase at the growing ends, maturation ameloblasts depicted a different pattern of staining displaying the reactions only sporadically in molars. These data indicate the role of cholinesterase in the enamel organ in tooth morphogenesis and function of guinea pig teeth. PMID:15224211

  5. Chronic prenatal ethanol exposure alters glucocorticoid signalling in the hippocampus of the postnatal Guinea pig.

    PubMed

    Iqbal, U; Brien, J F; Banjanin, S; Andrews, M H; Matthews, S G; Reynolds, J N

    2005-09-01

    The present study tested the hypothesis that chronic prenatal ethanol exposure causes long-lasting changes in glucocorticoid signalling in postnatal offspring. Pregnant guinea pigs were treated with ethanol (4 g/kg maternal body weight/day), isocaloric-sucrose/pair-feeding or water throughout gestation, and maternal saliva cortisol concentration was determined 2 h after treatment at different stages of gestation. Electrically-stimulated release of glutamate and GABA, in the presence or absence of dexamethasone, as well as glucocorticoid and mineralocorticoid receptor mRNA expression, was determined in the hippocampus and prefrontal cortex of adult offspring of treated pregnant guinea pigs. Maternal saliva cortisol concentration increased throughout pregnancy, which was associated with increased foetal plasma and amniotic fluid cortisol concentration. Ethanol administration to pregnant guinea pigs increased maternal saliva cortisol concentration during early and mid-gestation. In late gestation, ethanol administration did not increase saliva cortisol concentration above that induced by pregnancy. Chronic prenatal ethanol exposure had no effect on stimulated glutamate or GABA release, but selectively prevented dexamethasone-mediated suppression of stimulated glutamate release, and decreased expression of mineralocorticoid, but not glucocorticoid, receptor mRNA in the hippocampus of adult offspring. These data indicate that maternal ethanol administration leads to excessively increased maternal cortisol concentration that can impact negatively the developing foetal brain, leading to persistent postnatal deficits in glucocorticoid regulation of glutamate signalling in the adult hippocampus. PMID:16101899

  6. Endogenous leukotriene D/sub 4/ formation during anaphylactic shock in the guinea pig

    SciTech Connect

    Keppler, A.; Oerning, L.; Bernstroem, K.; Hammarstroem, S.

    1987-08-01

    Experiments on the metabolism and excretion of i.v. administered selectively labeled (/sup 3/H/sub 8/)leukotriene C/sub 4/ in bile duct-cannulated guinea pigs indicated predominantly biliary excretion of tritium. The major leukotriene metabolite in bile was identified as leukotriene D/sub 4/. By monitoring leukotriene excretion radioimmunochromatographically, it was shown that guinea pigs suffering from anaphylactic shock produce leukotriene D/sub 4/ endogenously. Immunological challenge of animals sensitized to ovalbumin was accompanied by an increase of biliary leukotriene D/sub 4/ concentrations from 10 +/- 1 to 86 +/- 10 nM. When considering that bile flow was decreased to about half after challenge, the excretion rate of leukotriene D/sub 4/ in bile increased from 0.88 +/- 0.16 before 3.18 +/- 0.38 pmol x min/sup -1/ x kg/sup -1/ after challenge. It is concluded that systemic anaphylaxis in the guinea pig is associated with endogenous generation of leukotriene C/sub 4/.

  7. Cardiac actions of phencyclidine in isolated guinea pig and rat heart: possible involvement of slow channels

    SciTech Connect

    Temma, K.; Akera, T.; Ng, Y.C.

    1985-03-01

    The mechanisms responsible for the positive inotropic effect of phencyclidine were studied in isolated preparations of guinea pig and rat heart. In electrically paced left atrial muscle preparations, phencyclidine increased the force of contraction; rat heart muscle preparations were more sensitive than guinea pig heart muscle preparations. The positive inotropic effect of phencyclidine was not significantly reduced by a combination of phentolamine and nadolol; however, the effect was competitively blocked by verapamil in the presence of phentolamine and nadolol. Inhibition of the outward K+ current by tetraethylammonium chloride also produced a positive inotropic effect; however, the effect of tetraethylammonium was reduced by phentolamine and nadolol, and was almost insensitive to verapamil. The inotropic effect of phencyclidine was associated with a marked prolongation of the action potential duration and a decrease in maximal upstroke velocity of the action potential, with no change in the resting membrane potential. The specific (/sup 3/H)phencyclidine binding observed with membrane preparations from guinea pig ventricular muscle was saturable with a single class of high-affinity binding site. This binding was inhibited by verapamil, diltiazem, or nitrendipine, but not by ryanodine or tetrodotoxin. These results suggest that the positive inotropic effect of phencyclidine results from enhanced Ca/sup 2 +/ influx via slow channels, either by stimulation of the channels or secondary to inhibition of outward K/sup +/ currents.

  8. Intimal permeability evaluated in a short-term organ culture of diabetic guinea pig aorta

    SciTech Connect

    Schlosser, M.J.; Verlangieri, A.J.

    1988-01-01

    A novel short-term organ culture system was used to evaluate intimal permeability changes by measuring aortic (/sup 14/C)methylated albumin accumulation. Aortic plugs were removed from the upper thoracic aorta of male guinea pigs and maintained in serum-free media. The accumulation of (/sup 14/C)albumin in the intimal-medial layer was determined after a 5 h incubation. In preliminary studies, albumin recovered from intimal-injured aortic plugs was significantly greater than those from non-injured plugs. Aortic plugs from streptozotocin-treated guinea pigs, diabetic for 3 weeks, also accumulated significantly more (/sup 14/C)albumin than plugs from nondiabetic controls. Histological changes were not observed in the aorta of either the diabetic or control group. A strong significant inverse correlation was found between plasma ascorbic acid levels and (/sup 14/C)-activity recovered from aortic plugs. This study demonstrates a simple and rapid method for assessing aortic permeability changes under a well-defined in vitro system, and suggests that vascular permeability changes in the streptozotocin-diabetic guinea pig may be associated with an ascorbic acid deficit.

  9. U-60,257 inhibits O3-induced bronchial hyperreactivity in the guinea pig

    SciTech Connect

    Murlas, C.; Lee, H.K.

    1985-10-01

    We studied the effects on ozone-induced airway hyperreactivity of U-60,257, a pyrroloprostacyclin shown to inhibit leukotriene C/D biosynthesis in vitro. A group of 5 guinea pigs were pretreated with U-60,257 (5 mg/kg IV), and studied before and 30 min after a 15 min exposure to 3.0 ppm ozone. These animals were compared to a similarly exposed group that was untreated (n = 10). Reactivity was determined by measuring specific airway resistance (SRaw) upon intravenous acetylcholine infusion in unanesthetized, spontaneously breathing animals. Prior to ozone exposure, we found that U-60,257 treatment did not affect either SRaw or muscarinic reactivity. After exposure to 3.0 ppm, all untreated guinea pigs showed substantial muscarinic hyperreactivity. In contrast, no significant change in SRaw or muscarinic reactivity occurred after ozone in any animal pretreated with U-60,257. We conclude that ozone-induced bronchial hyperreactivity in the guinea pig rapidly develops after a brief, high level exposure. This effect may be mediated, in part, by leukotrienes generated upon ozone exposure.

  10. Estimation of guinea pig tracheobronchial transport rates using a compartmental model

    SciTech Connect

    Velasquez, D.J.; Morrow, P.E.

    1984-01-01

    Mucociliary clearance in the tracheobronchial tree of guinea pigs was examined using monodisperse 7.9 ..mu..m MMAD polystyrene particles. Animals were exposed for approximately 1 h by inhalation via an intratracheal tube to aerosols tagged with gold-198 and fluorescent dyes. Following exposure, animals were radioactively monitored and sacrificed at predetermined times. The lungs were removed, freeze-dried, sectioned completely, and examined with a fluorescent microscope. Measurements were made of airway diameters where particles were found. An anatomic model for guinea pig lung morphology was used to assign ranges of airway diameters to five zones, which were incorporated into a compartmental model for lung clearance. Kinetic analysis of particle distributions in the zones led to development of first-order equations describing the compartmental clearance. Rate constants obtained from the kinetic analysis were used to estimate mucociliary transport rates in specific bronchial generations, which ranged from approximately 0.001 mm/min in the distal bronchioles to approximately 8 mm/min in the trachea, and resulted in a calculated 24-h clearance time for tracheobronchial clearance in the guinea pig. No evidence for either bronchial penetration by particles or relatively prolonged bronchial retention of particles was found in this study. 22 references, 3 figures, 3 tables.

  11. Catecholamine secretion by chemical hypoxia in guinea-pig, but not rat, adrenal medullary cells: differences in mitochondria.

    PubMed

    Harada, K; Endo, Y; Warashina, A; Inoue, M

    2015-08-20

    The effects of mitochondrial inhibitors (CN(-), a complex IV inhibitor and CCCP, protonophore) on catecholamine (CA) secretion and mitochondrial function were explored functionally and biochemically in rat and guinea-pig adrenal chromaffin cells. Guinea-pig chromaffin cells conspicuously secreted CA in response to CN(-) or CCCP, but rat cells showed a little, if any, secretory response to either of them. The resting metabolic rates in rat adrenal medullae did not differ from those in guinea-pig adrenal medullae. On the other hand, the time course of depolarization of the mitochondrial membrane potential (ΔΨm) in guinea-pig chromaffin cells in response to CN(-) was slower than that in rat chromaffin cells, and this difference was abolished by oligomycin, an F1F0-ATPase inhibitor. The extent of CCCP-induced decrease in cellular ATP in guinea-pig chromaffin cells, which was indirectly measured using a Mg(2+) indicator, was smaller than that in rat chromaffin cells. Relative expression levels of F1F0-ATPase inhibitor factor in guinea-pig adrenal medullae were smaller than in rat adrenal medullae, and the opposite was true for F1F0-ATPase α subunit. The present results indicate that guinea-pig chromaffin cells secrete more CA in response to a mitochondrial inhibitor than rat chromaffin cells and this higher susceptibility in the former is accounted for by a larger extent of reversed operation of F1F0-ATPase with the consequent decrease in ATP under conditions where ΔΨm is depolarized. PMID:26047729

  12. Covalent binding of nitroso-sulfonamides to glutathione S-transferase in guinea pigs with delayed type hypersensitivity.

    PubMed

    Eyanagi, Reiko; Toda, Akihisa; Imoto, Masumi; Uchiyama, Hidemori; Ishii, Yuji; Kuroki, Hiroaki; Kuramoto, Yukako; Soeda, Shinji; Shimeno, Hiroshi

    2012-04-01

    Drug induced allergies are believed to be induced by conjugates consisting of biological macromolecules and active metabolites. The present study investigated whether guinea pig glutathione S-transferase (gpGST), a protein that binds with sulfanilamide (SA) and sulfamethoxazole (SMX), could be detected in the liver cytosol fraction of guinea pigs that intraperitoneally received SA or SMX, and whether gpGST is a carrier protein. We synthesized three nitroso compounds, i.e., 4-nitroso-sulfanilamide (SA-NO), 4-nitrososulfamethoxazole (SMX-NO) and fluorescent-labeled nitroso compound (DNSBA-NO), and examined binding quantities of nitroso compounds to gpGST purified from untreated female guinea pigs. Furthermore, the concentrations of IgG in serum antibody for nitroso compounds were estimated using ELISA. When guinea pigs were sensitized using the three nitroso compounds, the dose dependent skin reactions were confirmed with each compound. In addition, sensitized guinea pigs using each nitroso compound showed positive skin reactions at an elicitation test performed using gpGST alone. The results confirmed synthesis of antibody against gpGST due to hapten sensitization. Therefore, when a nitroso compound binds with gpGST in the body of guinea pigs, nitroso-gpGST acts as a neoantigen, which induces synthesis of autoantibody. Thus, gpGST appears to be one of the carrier proteins that induce sulfa drug-induced allergies. Immunization of guinea pigs with active metabolite of drugs may give information for predicting the occurrence of delayed type hypersensitivity in human. PMID:22342371

  13. Characterization of the guinea pig animal model and subsequent comparison of the behavioral effects of selective dopaminergic drugs and methamphetamine

    PubMed Central

    Lee, Kiera-Nicole; Pellom, Samuel T.; Oliver, Ericka; Chirwa, Sanika

    2014-01-01

    Though not commonly used in behavior tests guinea pigs may offer subtle behavior repertoires that better mimic human activity and warrant study. To test this, 31 Hartley guinea pigs (male, 200–250 g) were evaluated in PhenoTyper cages using the video-tracking EthoVision XT 7.0 software. Results showed that guinea pigs spent more time in the hidden zone (small box in corner of cage) than the food/water zone, or arena zone. Guinea pigs exhibited thigmotaxis (a wall following strategy) and were active throughout the light and dark phases. Eating and drinking occurred throughout the light and dark phases. An injection of 0.25 mg/kg SCH23390, the dopamine D1 receptors (D1R) antagonist, produced significant decreases in time spent in the hidden zone. There were insignificant changes in time spent in the hidden zone for guinea pigs treated with 7.5 mg SKF38393 (D1R agonist), 1.0 mg/kg sulpiride (D2R antagonist), and 1.0 or 10.0 mg/kg methamphetamine. Locomotor activity profiles were unchanged after injections of saline, SKF38393, SCH23390 and sulpiride. By contrast, a single injection or repeated administration for 7 days of low-dose methamphetamine induced transient hyperactivity but this declined to baseline levels over the 22-hour observation period. Guinea pigs treated with high-dose methamphetamine displayed sustained hyperactivity and travelled significantly greater distances over the circadian cycle. Subsequent 7-day treatment with high-dose methamphetamine induced motor sensitization and significant increases in total distances moved relative to single drug injections or saline controls. These results highlight the versatility and unique features of the guinea pig for studying brain-behavior interactions. PMID:24436154

  14. Characterization of the guinea pig animal model and subsequent comparison of the behavioral effects of selective dopaminergic drugs and methamphetamine.

    PubMed

    Lee, Kiera-Nicole; Pellom, Samuel T; Oliver, Ericka; Chirwa, Sanika

    2014-05-01

    Although not commonly used in behavior tests guinea pigs may offer subtle behavior repertoires that better mimic human activity and warrant study. To test this, 31 Hartley guinea pigs (male, 200-250 g) were evaluated in PhenoTyper cages using the video-tracking EthoVision XT 7.0 software. Results showed that guinea pigs spent more time in the hidden zone (small box in corner of cage) than the food/water zone, or arena zone. Guinea pigs exhibited thigmotaxis (a wall following strategy) and were active throughout the light and dark phases. Eating and drinking occurred throughout the light and dark phases. An injection of 0.25 mg/kg SCH23390, the dopamine D1 receptors (D1R) antagonist, produced significant decreases in time spent in the hidden zone. There were insignificant changes in time spent in the hidden zone for guinea pigs treated with 7.5 mg SKF38393 (D1R agonist), 1.0 mg/kg sulpiride (D2R antagonist), and 1.0 or 10.0 mg/kg methamphetamine. Locomotor activity profiles were unchanged after injections of saline, SKF38393, SCH23390, and sulpiride. By contrast, a single injection or repeated administration for 7 days of low-dose methamphetamine induced transient hyperactivity but this declined to baseline levels over the 22-h observation period. Guinea pigs treated with high-dose methamphetamine displayed sustained hyperactivity and travelled significantly greater distances over the circadian cycle. Subsequent 7-day treatment with high-dose methamphetamine induced motor sensitization and significant increases in total distances moved relative to single drug injections or saline controls. These results highlight the versatility and unique features of the guinea pig for studying brain-behavior interactions.

  15. Catecholamine secretion by chemical hypoxia in guinea-pig, but not rat, adrenal medullary cells: differences in mitochondria.

    PubMed

    Harada, K; Endo, Y; Warashina, A; Inoue, M

    2015-08-20

    The effects of mitochondrial inhibitors (CN(-), a complex IV inhibitor and CCCP, protonophore) on catecholamine (CA) secretion and mitochondrial function were explored functionally and biochemically in rat and guinea-pig adrenal chromaffin cells. Guinea-pig chromaffin cells conspicuously secreted CA in response to CN(-) or CCCP, but rat cells showed a little, if any, secretory response to either of them. The resting metabolic rates in rat adrenal medullae did not differ from those in guinea-pig adrenal medullae. On the other hand, the time course of depolarization of the mitochondrial membrane potential (ΔΨm) in guinea-pig chromaffin cells in response to CN(-) was slower than that in rat chromaffin cells, and this difference was abolished by oligomycin, an F1F0-ATPase inhibitor. The extent of CCCP-induced decrease in cellular ATP in guinea-pig chromaffin cells, which was indirectly measured using a Mg(2+) indicator, was smaller than that in rat chromaffin cells. Relative expression levels of F1F0-ATPase inhibitor factor in guinea-pig adrenal medullae were smaller than in rat adrenal medullae, and the opposite was true for F1F0-ATPase α subunit. The present results indicate that guinea-pig chromaffin cells secrete more CA in response to a mitochondrial inhibitor than rat chromaffin cells and this higher susceptibility in the former is accounted for by a larger extent of reversed operation of F1F0-ATPase with the consequent decrease in ATP under conditions where ΔΨm is depolarized.

  16. 9 CFR 113.38 - Guinea pig safety test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... shall be conducted when prescribed in a Standard Requirement or approved Outline of Production for a... specified in the Standard Requirement or approved Outline of Production for the product, a 2 ml dose shall... pigs during the observation period, the serial or subserial is unsatisfactory. If unfavorable...

  17. Strain-related differences in the tracheal responsiveness of sensitized guinea pig.

    PubMed

    Bidon, J C; Blin, M; Gogny, M; Vu, A T; Jondet, A

    1995-01-01

    The purpose of this study was to evaluate the strain-related differences in tracheal hyperresponsiveness in control and egg albumen-sensitized guinea pigs. Concentration-response curves to acetylcholine and barium chloride were established from tracheal rings of Dunkin-Hartley and BFA strain guinea pigs. In the Dunkin-Hartley strain, sensitization did not significantly increase the tracheal responsiveness to acetylcholine and barium chloride. By contrast, in the BFA strain, significant sensitization-induced hyperreactivity was achieved as the maximal contractions induced by acetylcholine and barium chloride, were enhanced from 6.5 +/- 1.2 and 3.2 +/- 0.4 mN in control to 10.0 +/- 1.4 and 5.6 +/- 0.8 mN, respectively, in sensitized animals. However, antigen challenge, performed in vitro, exhibited a similar amplitude of contraction in tracheal rings from both strains (Dunkin-Hartley 5.1 +/- 0.8 mN; BFA 5.9 +/- 0.5 mN). Finally, while the two guinea-pig strains developed specific sensitization to allergen, only tracheal rings from the BFA strain developed hyperresponsiveness to acetylcholine and barium chloride. The strain-related difference appears to be partly explained by a lower basal reactivity in the BFA strain both acetylcholine (Em 7.3 +/- 1.7 and 6.5 +/- 1.2 mN for Dunkin-Hartley and BFA, respectively) and barium chloride (Em 9.4 +/- 2.6 and 3.2 +/- 0.4 mN for Dunkin-Hartley and BFA, respectively). As the same procedure of sensitization provides different results in the genesis of hyperreactivity between the two guinea-pig strains used for asthma models, the BFA guinea-pig strain seems to be a better model because sensitized non-challenged animals could easily be dissociated from control ones, similar to that which occurs in asthmatic patients during provocation tests with cholinergic drugs. PMID:7812171

  18. Passive sensitization of skin and lung by guinea-pig immunoglobulins

    PubMed Central

    Colquhoun, D.; Brocklehurst, W. E.

    1965-01-01

    Guinea-pig γ1- and γ2-globulins have been purified by preparative electrophoresis followed by chromatography. No γ1-globulin was detectable in purified γ2-globulin, but purified γ1-globulin always contained fast γ2-globulin. Normal guinea-pig serum contained much less γ1-globulin than immune serum. Antisera prepared against normal guinea-pig serum did not contain useful amounts of antibody specific for γ1-globulin. Guinea-pig lung tissue was sensitized by very low concentrations of guinea-pig γ1-globulin (of the order of 6×10-10 molar) but γ2-globulin antibodies were almost inactive. No evidence was found that the trace of activity in γ2-globulin was not due to very slight contamination with γ1-globulin antibodies. The finding that γ1-globulin antibodies are far more potent than γ2-globulin antibodies in sensitizing skin has been confirmed, but several lines of evidence suggest that γ2-globulin antibodies may also have weak activity. Thus quantitative passive cutaneous anaphylaxis (PCA) tests showed that whenever the γ2-globulin fraction contained antibody it appeared far more potent relative to γ1-globulin than when the same proteins were tested on lung tissue. The PCA activity of moderate amounts of purified γ2-globulin antibodies disappeared faster than the skin sensitization produced by small amounts of γ1-globulin antibodies, and the γ2-globulin preparations did not contain enough γ1-globulin impurity to account for their PCA activity. No inhibition of skin responses was observed with the largest doses of antigen tested. The most plausible explanation of these results is that, under the conditions of our experiments, γ2-globulin antibody had weak PCA activity. Objections to this hypothesis are discussed. The PCA activity of γ2-globulin antibody probably involves a mechanism different from that of the sensitization produced by the highly potent γ1-globulin antibody. ImagesFIG. 4FIG. 5FIG. 6FIG. 7FIG. 8FIG. 9 PMID:4159033

  19. Pathogenesis of a genotype C strain of bovine parainfluenza virus type 3 infection in albino guinea pigs.

    PubMed

    Shi, Hong-Fei; Zhu, Yuan-Mao; Dong, Xiu-Mei; Cai, Hong; Ma, Lei; Wang, Shu; Yan, Hao; Wang, Xue-Zhi; Xue, Fei

    2014-08-01

    Bovine parainfluenza virus type 3 (BPIV3) is one of the most important of the known viral respiratory tract agents of both young and adult cattle and widespread among cattle around the world. Up to present, three genotypes A, B and C of BPIV3 have been described on the basis of genetic and phylogenetic analysis and only limited studies on the pathogenesis of the genotype A of BPIV3 infection in calves and laboratory animals have been performed. The report about experimental infections of the genotypes B and C of BPIV3 in laboratory animals and calves was scant. Therefore, an experimental infection of guinea pigs with the Chinese BPIV3 strain SD0835 of the genotype C was performed. Sixteen guinea pigs were intranasally inoculated with the suspension of SD0835, while eight control guinea pigs were also intranasally inoculated with the same volume of supernatant from uninfected MDBK cells. The virus-inoculated guinea pigs displayed a few observable clinical signs that were related to the respiratory tract disease and two of the sixteen experimentally infected guinea pigs died at 2 and 3 days post inoculation (PI), respectively, and apparent gross pneumonic lesions were observed at necropsy. The gross pneumonic lesions in guinea pigs inoculated with SD0835 consisted of dark red, slightly depressed, irregular areas of consolidation in the lung lobes from the second to 9th day of infection at necropsy, and almost complete consolidation and atelectasis of the lung lobes were seen at 7 days PI. Histopathological changes including alveoli septa thickening and focal cellulose pneumonia were also observed in the lungs of guinea pigs experimentally infected with SD0835. Viral replication was detectable by virus isolation and titration, real-time RT-PCR and immunohistochemistry (IHC) staining in the respiratory tissues of guinea pigs as early as 24h after intranasal inoculation with SD0835. The results of virus isolation and titration showed that guinea pigs were permissive for

  20. Effect of pregnancy on vasopressin-mediated responses in guinea-pig uterine arteries with intact and denuded endothelium.

    PubMed

    Jovanović, A; Grbović, L; Jovanović, S; Zikić, I

    1995-07-01

    The effect of pregnancy on vasopressin-induced contraction of guinea-pig uterine arterial rings was investigated. Initially, vasopressin induced contraction (pD2 = 9.14) in pregnant guinea-pig uterine artery with greater potency than in non-pregnant guinea-pig uterine artery (pD2 = 8.77). Removal of the endothelium did not affect vasopressin-induced contractions, regardless of pregnancy status. In all types of preparations, [d(CH2)5Tyr(Me)2]vasopressin (10-100 nM) and [d(CH2)5,D-Ile2,Ile4]vasopressin (300 nM-3 microM) produced parallel rightward shifts of the curves for vasopressin. The Schild plots constrained to a slope of unity gave the following -log KB values: [d(CH2)5Tyr(Me)2]vasopressin vs. [d(CH2)5,D-Ile2,Ile4]vasopressin 8.74 vs. 6.82 and 8.50 vs. 6.72 for non-pregnant guinea-pig uterine artery with intact and denuded endothelium, respectively; 8.38 vs. 6.49 and 8.36 vs. 6.75 for pregnant guinea-pig uterine artery with intact and denuded endothelium, respectively. The pKA values for vasopressin itself also did not differs between preparations: 6.49 and 6.55 for non-pregnant guinea-pig uterine artery with intact and denuded endothelium, respectively; 6.48 and 6.52 for pregnant guinea-pig uterine artery with intact and denuded endothelium, respectively. The receptor reserve (KA/EC50) was significantly greater in preparations taken from pregnant than from non-pregnant animals. It is concluded that vasopressin-induced contractions of guinea-pig uterine artery are not modulated by the endothelium, regardless of pregnancy status. The receptor reserve for vasopressin in guinea-pig uterine artery is increased during pregnancy, that is not related to the changes of vasopressin receptor affinity for vasopressin. It is probable that vasopressin receptors involved in vasopressin-induced contraction of all types of vessels studied belong to the V1A-like subtype.

  1. Ascorbic acid suppresses endotoxemia and NF-κB signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach

    SciTech Connect

    Abhilash, P.A.; Harikrishnan, R.; Indira, M.

    2014-01-15

    Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-κB activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKKβ and the protein expressions of phospho-IκBα, NF-κB, TNF-α, TGF-β{sub 1} and IL-6 were also altered in ethanol group. The expressions of fibrosis markers α-SMA, α{sub 1} (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-κB activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKKβ, which decreased the activation of NF-κB and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-κB activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKKβ and alteration of

  2. The effects of compensated cardiac hypertrophy on dihydropyridine and ryanodine receptors in rat, ferret and guinea-pig hearts.

    PubMed

    Rannou, F; Sainte-Beuve, C; Oliviero, P; Do, E; Trouvé, P; Charlemagne, D

    1995-05-01

    The number of dihydropyridine and ryanodine receptors (DHP-R and RyR) has been measured in control and hypertrophied ventricles from rats, guinea pigs and ferrets to determine whether these two channels contribute to the alterations in excitation-contraction coupling (ECC), and in Ca2+ transient during compensated cardiac hypertrophy. We found that ventricular hypertrophy did not change the density of DHP-R. Mild hypertrophy did not alter the density of RyR in the rat but decreased it in the guinea-pig and in the ferret (30% and 36%, respectively). Severe hypertrophy decreased the density of RyR by 20% in the rat and by 34% in the guinea-pig. Therefore, the decrease is greater in ferret and guinea-pig hearts than in rat heart. We conclude that the sarcoplasmic reticulum (SR) Ca2+ release channels but not the L-type Ca2+ channels could contribute to the slowing of intracellular Ca2+ movements and to the reduced velocity of shortening of the hypertrophied hearts. We suggest that, in the guinea pig and ferret hearts which express only the beta myosin heavy chain (MHC) isoform, the reduced velocity of shortening during hypertrophy is related to the decrease in RyR density, whereas in the rat, it is regulated primarily via a shift in the MHC isoform, except in severe hypertrophy in which the moderate decrease in RyR would also be involved. PMID:7473781

  3. Changes in pulmonary lavage fluid of guinea pigs exposed to ultrafine zinc oxide with adsorbed sulfuric acid

    SciTech Connect

    Conner, M.W.; Flood, W.H.; Rogers, A.E.; Amdur, M.O.

    1989-01-01

    Ultrafine metal oxide particles (diameters less than 0.1 microns) and sulfur dioxide are important products of coal combustion. Interaction of these products in the effluent stream results in formation of ultrafine particles with adsorbed sulfur compounds, including sulfuric acid. The toxicity of ultrafine zinc oxide particles with adsorbed sulfuric acid was evaluated by comparing pulmonary lavage fluid from guinea pigs exposed for 1, 2, 3, 4, or 5 consecutive daily 3-h periods to ultrafine zinc oxide generated in the presence of sulfur dioxide (ZnO + SO/sub 2/) to pulmonary lavage fluid from guinea pigs exposed to an equivalent concentration of ultrafine ZnO. Two groups of guinea pigs exposed either to SO/sub 2/ or to particle-free furnace gas served as additional controls. Cells, protein, and activities of lactate dehydrogenase, acid phosphatase, and alkaline phosphatase were increased in lavage fluid obtained from guinea pigs exposed to ZnO + SO/sub 2/ as compared to guinea pigs exposed to ZnO. These results demonstrate the potential importance of ultrafine metal oxides as carries of sulfuric acid derived from fossil fuel combustion.

  4. High-fat diet-dependent modulation of the delayed rectifier K(+) current in adult guinea pig atrial myocytes.

    PubMed

    Aromolaran, Ademuyiwa S; Colecraft, Henry M; Boutjdir, Mohamed

    2016-06-01

    Obesity is associated with hyperlipidemia, electrical remodeling of the heart, and increased risk of supraventricular arrhythmias in both male and female patients. The delayed rectifier K(+) current (IK), is an important regulator of atrial repolarization. There is a paucity of studies on the functional role of IK in response to obesity. Here, we assessed the obesity-mediated functional modulation of IK in low-fat diet (LFD), and high-fat diet (HFD) fed adult guinea pigs. Guinea pigs were randomly divided into control and obese groups fed, ad libitum, with a LFD (10 kcal% fat) or a HFD (45 kcal% fat) respectively. Action potential duration (APD), and IK were studied in atrial myocytes and IKr and IKs in HEK293 cells using whole-cell patch clamp electrophysiology. HFD guinea pigs displayed a significant increase in body weight, total cholesterol and total triglycerides within 50 days. Atrial APD at 30% (APD30) and 90% (APD90) repolarization were shorter, while atrial IK density was significantly increased in HFD guinea pigs. Exposure to palmitic acid (PA) increased heterologously expressed IKr and IKs densities, while oleic acid (OA), severely reduced IKr and had no effect on IKs. The data are first to show that in obese guinea pigs abbreviated APD is due to increased IK density likely through elevations of PA. Our findings may have crucial implications for targeted treatment options for obesity-related arrhythmias.

  5. Bronchointerstitial pneumonia in guinea pigs following inoculation with H5N1 high pathogenicity avian influenza virus.

    PubMed

    Kwon, Y K; Lipatov, A S; Swayne, D E

    2009-01-01

    The H5N1 high-pathogenicity avian influenza (HPAI) viruses have caused widespread disease of poultry in Asia, Africa and the Middle East, and sporadic human infections. The guinea pig model has been used to study human H3N2 and H1N1 influenza viruses, but knowledge is lacking on H5N1 HPAI virus infections. Guinea pigs were inoculated intranasally or intragastrically with A/Vietnam/1203/04 (VN/04) or A/Muscovy duck/Vietnam/209/05 (MDk/VN/05) viruses. Mild listlessness was seen at 2 and 3 days postinoculation (DPI) in guinea pigs inoculated intranasally with VN/04 virus. At 5 DPI, the guinea pigs had bronchointerstitial pneumonia and virus was identified in bronchiolar epithelium and alveolar macrophages. Virus was isolated from the lungs but was lacking from other organs. Minimal lung lesions were seen in intranasal MDk/VN/06 group and virus was not detected, but serologic evidence of infection was observed. Intragastric exposure failed to produce infection or lesions with either virus. The localized respiratory disease in guinea pigs with H5N1 viruses was very similar to that of H3N2 and H1N1 influenza in humans and was less severe than reported for H5N1 human cases.

  6. Molecular basis of non-responsiveness to peroxisome proliferators: the guinea-pig PPARalpha is functional and mediates peroxisome proliferator-induced hypolipidaemia.

    PubMed Central

    Bell, A R; Savory, R; Horley, N J; Choudhury, A I; Dickins, M; Gray, T J; Salter, A M; Bell, D R

    1998-01-01

    The guinea pig does not undergo peroxisome proliferation in response to peroxisome proliferators, in contrast with other rodents. To understand the molecular basis of this phenotype, the peroxisome proliferator activated receptor alpha (PPARalpha) from guinea-pig liver was cloned; it encodes a protein of 467 amino acid residues that is similar to rodent and human PPARalpha. The guinea-pig PPARalpha showed a high substitution rate: maximum likelihood analysis was consistent with rodent monophyly, but could not exclude rodent polyphyly (P approximately 0.06). The guinea-pig PPARalpha cDNA was expressed in 293 cells and mediated the induction of the luciferase reporter gene by the peroxisome proliferator, Wy-14,643, dependent on the presence of a peroxisome proliferator response element. Moreover the PPARalpha RNA and protein were expressed in guinea-pig liver, although at lower levels than in a species which is responsive to peroxisome proliferators, the mouse. To determine whether the guinea-pig PPARalpha mediated any physiological effects, guinea pigs were exposed to two selective PPARalpha agonists, Wy-14, 643 and methylclofenapate; both compounds induced hypolipidaemia. Thus the guinea pig is a useful model for human responses to peroxisome proliferators. PMID:9620871

  7. [Effects of dietary fat composition on food anaphylaxis and formaldehyde sensitization in guinea pigs].

    PubMed

    Malikova, N A; Pestova, M I; Krzhechkovskaia, V V; Gmoshinskiĭ, I V; Mazo, V K

    1993-01-01

    Adult guinea pigs were fed for 10-14 days with synthetic diets, fat constituting 11% of its total energy. Dietary fat was composed of coconut, corn, dairy and soybean oils mixtures with ratio of polyunsaturated fatty acids (PUFA) omega-6 to PUFA omega-3 equal to 24.2 (K1) or 5.53 (K2). The animals were sensitized orally by pasteurized cow milk (PCM) or epicutaneously by formaldehyde (F) during these diets feeding. The degree of the sensitization was assessed in the reaction of active anaphylactic shock (AAS) in PCM-sensitized animals and in the reaction of leukocytes specific lysis (LSL) in F-sensitized guinea pigs. In the latter pigs the concentration of serum antibodies (Ab) against dietary soya protein was measured by ELISA. Animals fed by K1 and K2 were also tested for histamine mean lethal dose resistance. The lowest lethality in AAS, number of convulsions, of positive LSL cases and Ab level were found in animals fed by K1 compared to both K2 and to animals fed by common animal chew. Resistance to histamine was similar in K1 and K2 groups, but was significantly higher compared to control (chew) group. In convulsion, the changes in PUFA omega-6/PUFA omega-3 ratio have marked effect on different indices of allergic sensitivity. PMID:8042314

  8. The pathogenesis of leptospirosis I. Hemorrhages in experimental leptospirosis in guinea pigs.

    PubMed Central

    Higgins, R; Cousineau, G

    1977-01-01

    In experimental infections of guinea pigs with a virulent strain of Leptospira icterohaemorrhagiae widespread hemorrhages were observed. Thrombocytopenia, prolongation of prothrombin, thrombin, partial thromboplastin and coagulation times, decrease of plasma fibrinogen, factor V, factor VIII and the presence of fibrinogen degradation products were demonstrated. Treatment of infected guinea pigs with heparin prolonged life for two to three days. The histological observations revealed that the main lesion is a severe injury of the vasculature, mainly arteries, arterioles and capillaries. Most of the endothelial cells are affected or destroyed and the muscular fibers of arteries and arterioles are injured. With Martius-Scarlet-Blue, Weigert or Picro-Mallory stains it was demonstrated that the organization seen in the vessels is not all made of fibrin. The conclusion reached was that the hemorrhages observed in experimental leptospirosis in guines pigs are due to disseminated intravascular coagulation. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. 11. PMID:861835

  9. Protein and glycoprotein electrophoretic patterns of enriched fractions of primary and secondary granules from guinea pig polymorphonuclear leukocytes

    PubMed Central

    1975-01-01

    The postnuclear supernatant fraction of sucrose homogenates of guinea pig polymorphonuclear leukocytes (PMNL) was subjected to differential centrifugation to obtain a total particulate fraction, a particle-free supernatant fraction, highly enriched fractions of primary and secondary granules, and a membrane-rich fraction. The various fractions were solubilized in buffer containing sodium dodecyl sulfate (SDS) and analyzed for protein and glycoproteincomponents by SDS -polyacrylamide gel electrophoresis. The major glycoprotein components of the postnuclear supernatant fraction were found mainly associated with the enriched fraction of secondary granules and, to a lesser extent, with the membrane-rich fraction. No major glycoprotein components were visible in the polypeptide electrophoretic patterns of the primary granule fraction or of the particle-free supernate. Attempts at separation of guinea pig granules by zonal sucrose density gradient centrifugation were only partially successful. Data supporting a species difference in this regard between rabbit and guinea pig PMNL granules are presented. PMID:166079

  10. L-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs.

    PubMed

    Frikke-Schmidt, Henriette; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-04-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs-as in humans-is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis.

  11. Modification of Osteoarthritis in the Guinea Pig with Pulsed Low-Intensity Ultrasound Treatment

    PubMed Central

    Gurkan, Ilksen; Ranganathan, Archana; Yang, Xu; Horton, Walter E.; Todman, Martin; Huckle, James; Pleshko, Nancy; Spencer, Richard G.

    2010-01-01

    Objective The Hartley guinea pig develops articular cartilage degeneration similar to that seen in idiopathic human osteoarthritis. We investigated whether the application of pulsed low-intensity ultrasound (PLIUS) to the Hartley guinea pig joint would prevent or attenuate the progression of this degenerative process. Methods Treatment of male Hartley guinea pigs was initiated at the onset of degeneration (8 weeks of age) to assess the ability of PLIUS to prevent osteoarthritis, or at a later age (12 months) to assess the degree to which PLIUS acted to attenuate the progression of established disease. PLIUS (30 mW/cm2) was applied to stifle joints for 20 minutes per day over periods ranging from three to ten months, with contralateral limbs serving as controls. Joint cartilage histology was graded according to a modified Mankin scale to evaluate treatment effect. Immunohistochemical staining for IL-1 receptor antagonist (IL-1ra), MMP-3, MMP-13, and TGF-β1 was performed on the cartilage to evaluate patterns of expression of these proteins. Results PLIUS did not fully prevent cartilage degeneration in the prevention groups, but diminished the severity of the disease, with the treated joints showing markedly decreased surface irregularities and a much smaller degree of loss of matrix staining as compared to controls. PLIUS also attenuated disease progression in the groups with established disease, although to a somewhat lesser extent as compared to the prevention groups. Immunohistochemical staining demonstrated a markedly decreased degree of TGF-β1 production in the PLIUS-treated joints. This indicates less active endogenous repair, consistent with the marked reduction in cartilage degradation. Conclusions PLIUS exhibits the ability to attenuate the progression of cartilage degeneration in an animal model of idiopathic human OA. The effect was greater in the treatment of early, rather than established, degeneration. PMID:20175971

  12. Immunocytochemical evidence for SNARE protein-dependent transmitter release from guinea pig horizontal cells

    PubMed Central

    Lee, Helen; Brecha, Nicholas C.

    2013-01-01

    Horizontal cells are lateral interneurons that participate in visual processing in the outer retina but the cellular mechanisms underlying transmitter release from these cells are not fully understood. In non-mammalian horizontal cells, GABA release has been shown to occur by a non-vesicular mechanism. However, recent evidence in mammalian horizontal cells favors a vesicular mechanism as they lack plasmalemmal GABA transporters and some soluble NSF attachment protein receptor (SNARE) core proteins have been identified in rodent horizontal cells. Moreover, immunoreactivity for GABA and the molecular machinery to synthesize GABA have been found in guinea pig horizontal cells, suggesting that if components of the SNARE complex are expressed they could contribute to the vesicular release of GABA. In this study we investigated whether these vesicular and synaptic proteins are expressed by guinea pig horizontal cells using immunohistochemistry with well-characterized antibodies to evaluate their cellular distribution. Components of synaptic vesicles including vesicular GABA transporter, synapsin I and synaptic vesicle protein 2A were localized to horizontal cell processes and endings, along with the SNARE core complex proteins, syntaxin-1a, syntaxin-4 and synaptosomal-associated protein 25 (SNAP-25). Complexin I/II, a cytosolic protein that stabilizes the activated SNARE fusion core, strongly immunostained horizontal cell soma and processes. In addition, the vesicular Ca2+-sensor, synaptotagmin-2, which is essential for Ca2+-mediated vesicular release, was also localized to horizontal cell processes and somata. These morphological findings from guinea pig horizontal cells suggest that mammalian horizontal cells have the capacity to utilize a regulated Ca2+-dependent vesicular pathway to release neurotransmitter, and that this mechanism may be shared among many mammalian species. PMID:20384779

  13. Role of ion channels in sepsis-induced atrial tachyarrhythmias in guinea pigs

    PubMed Central

    Aoki, Yuta; Hatakeyama, Noboru; Yamamoto, Seiji; Kinoshita, Hiroyuki; Matsuda, Naoyuki; Hattori, Yuichi; Yamazaki, Mitsuaki

    2012-01-01

    BACKGROUND AND PURPOSE Supraventricular tachyarrhythmias, including atrial fibrillation, are occasionally observed in patients suffering from sepsis. Modulation of cardiac ion channel function and expression by sepsis may have a role in the genesis of tachyarrhythmias. EXPERIMENTAL APPROACH Sepsis was induced by LPS (i.p.; 300 µg·kg−1) in guinea pigs. Membrane potentials and ionic currents were measured in atrial myocytes isolated from guinea pigs 10 h after LPS, using whole cell patch-clamp methods. KEY RESULTS In atrial cells from LPS-treated animals, action potential duration (APD) was significantly shortened. It was associated with a reduced L-type Ca2+ current and an increased delayed rectifier K+ current. These electrophysiological changes were eliminated when NG-nitro-l-arginine methyl ester (l-NAME) or S-ethylisothiourea was given together with LPS. In atrial tissues from LPS-treated animals, Ca2+ channel subunits (Cav1.2 and Cav1.3) decreased and delayed rectifier K+ channel subunits (Kv11.1 and Kv7.1) increased. However, L-NAME treatment did not substantially reverse such changes in atrial expression in LPS-treated animals, with the exception that Kv11.1 subunits returned to control levels. After LPS injection, inducible NOS in atrial tissues was up-regulated, and atrial NO production clearly increased. CONCLUSIONS AND IMPLICATIONS In atrial myocytes from guinea pigs with sepsis, APD was significantly shortened. This may reflect nitration of the ion channels which would alter channel functions, rather than changes in atrial expression of the channels. Shortening of APD could serve as one of the mechanisms underlying atrial tachyarrhythmia in sepsis. PMID:22050008

  14. Integration of Pulse Trains in Humans and Guinea Pigs with Cochlear Implants.

    PubMed

    Zhou, Ning; Kraft, Casey T; Colesa, Deborah J; Pfingst, Bryan E

    2015-08-01

    Temporal integration (TI; threshold versus stimulus duration) functions and multipulse integration (MPI; threshold versus pulse rate) functions were measured behaviorally in guinea pigs and humans with cochlear implants. Thresholds decreased with stimulus duration at a fixed pulse rate and with pulse rate at a fixed stimulus duration. The rates of threshold decrease (slopes) of the TI and MPI functions were not statistically different between the guinea pig and human subject groups. A characteristic of the integration functions that the two groups shared was that the slopes of the TI functions were similar in magnitude to slopes of the MPI function only at low pulse rates (< approximately 300 pulses per second). This is consistent with the notion that the TI functions and the MPI functions at the low rates are mediated by a mechanism of long-term integration described in the statistical "multiple looks" model. Histological analysis of the guinea pig cochleae suggested that the slopes of both the MPI and the TI functions were dependent on sensory and neural health near the stimulated regions. The strongest predictor for spiral ganglion cell densities measured near the stimulation sites was the slope of the MPI functions below 1,000 pps. Several mechanisms may be considered to account for the association of shallow integration functions with poor sensory and neural status. These mechanisms are related to abnormal across-fiber synchronization, increased refractoriness and adaptation with impaired neural function, and steep growth of neural excitation with current level associated with neural pathology. The slope of the integration functions can potentially be used as a non-invasive measure for identifying stimulation sites with poor neural health and selecting those sites for removal or rehabilitation, but these applications remain to be tested. PMID:25990549

  15. Immediate post-dosing paralysis following severe soman and VX toxicosis in guinea pigs.

    PubMed

    Bide, R W; Schofield, L; Risk, D J

    2005-01-01

    There have been numerous studies of the central nervous system (CNS) involvement in organophosphate (OP) poisoning showing status epilepticus and/or 'electrographic seizures'. Brain damage has been demonstrated as 'neuronal necrosis' primarily in the cortex, thalamus and hippocampus. To the authors' knowledge there have been no reports of partial/total paralysis following close upon OP exposure although delayed paralysis has been reported. This report summarizes the immediate, OP induced paralytic events recorded in guinea pigs during development of the Canadian reactive skin decontaminant lotion (RSDL). As part of the development work, supra-lethal cutaneous doses of OP were applied to large numbers of guinea pigs followed by decontamination with the RSDL or predecessor lotions and solvents. Soman (pinacolyl methylphosphonofluoridate; GD) challenges were applied to 1277 animals and S-(2-diisopropyl-aminoethyl) methylphosphorothiolate (VX) challenges to 108. The classic sequence of clinical signs--ptyalism, tremors, fasciculations, convulsions, apnea and flaccid paralysis before death--was seen in the 658 animals that died and in many of the survivors. Eighty-four of 688 survivors of GD and 4 of 39 survivors of VX showed random paralysis of various distal regions following recovery from an insult which produced convulsions and/or flaccid paralysis. Because the experiments were designed to assess the decontamination procedures, there were no apparent relationships between the amounts of OP applied and the sequellae recorded. The observations of paralysis were also incidental to the prime focus of the experiments. Because of this, only ten animals paralysed following GD exposure were examined for histological effects. The pathologist diagnosed 'encephalomalacia' and 'focal necrotic lesions' in the cerebral cortex and 'focal necrotic lesions' in one spinal cord. Of the 84 guinea pigs paralysed after GD challenge, one was not decontaminated and the decontaminants used

  16. Receptors involved in the modulation of guinea pig urinary bladder motility by prostaglandin D2

    PubMed Central

    Guan, Na N; Svennersten, Karl; de Verdier, Petra J; Wiklund, N Peter; Gustafsson, Lars E

    2015-01-01

    Background and Purpose We have described a urothelium-dependent release of PGD2-like activity which had inhibitory effects on the motility of guinea pig urinary bladder. Here, we have pharmacologically characterized the receptors involved and localized the sites of PGD2 formation and of its receptors. Experimental Approach In the presence of selective DP and TP receptor antagonists alone or combined, PGD2 was applied to urothelium-denuded diclofenac-treated urinary bladder strips mounted in organ baths. Antibodies against PGD2 synthase and DP1 receptors were used with Western blots and for histochemistry. Key Results PGD2 inhibited nerve stimulation -induced contractions in strips of guinea pig urinary bladder with estimated pIC50 of 7.55 ± 0.15 (n = 13), an effect blocked by the DP1 receptor antagonist BW-A868C. After blockade of DP1 receptors, PGD2 enhanced the contractions, an effect abolished by the TP receptor antagonist SQ-29548. Histochemistry revealed strong immunoreactivity for PGD synthase in the urothelium/suburothelium with strongest reaction in the suburothelium. Immunoreactive DP1 receptors were found in the smooth muscle of the bladder wall with a dominant localization to smooth muscle membranes. Conclusions and Implications In guinea pig urinary bladder, the main effect of PGD2 is an inhibitory action via DP1 receptors localized to the smooth muscle, but an excitatory effect via TP receptors can also be evoked. The urothelium with its suburothelium might signal to the smooth muscle which is rich in PGD2 receptors of the DP1 type. The results are important for our understanding of regulation of bladder motility. PMID:25917171

  17. Maternal Vitamin C Deficiency during Pregnancy Persistently Impairs Hippocampal Neurogenesis in Offspring of Guinea Pigs

    PubMed Central

    Tveden-Nyborg, Pernille; Vogt, Lucile; Schjoldager, Janne G.; Jeannet, Natalie; Hasselholt, Stine; Paidi, Maya D.

    2012-01-01

    While having the highest vitamin C (VitC) concentrations in the body, specific functions of VitC in the brain have only recently been acknowledged. We have shown that postnatal VitC deficiency in guinea pigs causes impairment of hippocampal memory function and leads to 30% less neurons. This study investigates how prenatal VitC deficiency affects postnatal hippocampal development and if any such effect can be reversed by postnatal VitC repletion. Eighty pregnant Dunkin Hartley guinea pig dams were randomized into weight stratified groups receiving High (900 mg) or Low (100 mg) VitC per kg diet. Newborn pups (n = 157) were randomized into a total of four postnatal feeding regimens: High/High (Control); High/Low (Depleted), Low/Low (Deficient); and Low/High (Repleted). Proliferation and migration of newborn cells in the dentate gyrus was assessed by BrdU labeling and hippocampal volumes were determined by stereology. Prenatal VitC deficiency resulted in a significant reduction in postnatal hippocampal volume (P<0.001) which was not reversed by postnatal repletion. There was no difference in postnatal cellular proliferation and survival rates in the hippocampus between dietary groups, however, migration of newborn cells into the granular layer of the hippocampus dentate gyrus was significantly reduced in prenatally deficient animals (P<0.01). We conclude that a prenatal VitC deficiency in guinea pigs leads to persistent impairment of postnatal hippocampal development which is not alleviated by postnatal repletion. Our findings place attention on a yet unrecognized consequence of marginal VitC deficiency during pregnancy. PMID:23119033

  18. Mast cell mediators in citric acid-induced airway constriction of guinea pigs

    SciTech Connect

    Lin, C.-H.; Lai, Y.-L. . E-mail: tiger@ha.mc.ntu.edu.tw

    2005-08-15

    We demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. In this study, we further investigated the underlying mediator(s) for this type of airway constriction. At first, to examine effects caused by blocking agents, 67 young Hartley guinea pigs were divided into 7 groups: saline + CA; methysergide (serotonin receptor antagonist) + CA; MK-886 (leukotriene synthesis inhibitor) + CA; mepyramine (histamine H{sub 1} receptor antagonist) + CA; indomethacin (cyclooxygenase inhibitor) + CA; cromolyn sodium (mast cell stabilizer) + CA; and compound 48/80 (mast cell degranulating agent) + CA. Then, we tested whether leukotriene C{sub 4} (LTC{sub 4}) or histamine enhances CA-induced airway constriction in compound 48/80-pretreated guinea pigs. We measured dynamic respiratory compliance (Crs) and forced expiratory volume in 0.1 s (FEV{sub 0.1}) during either baseline or recovery period. In addition, we detected histamine level, an index of pulmonary mast cell degranulation, in bronchoalveolar lavage (BAL) samples. Citric acid aerosol inhalation caused decreases in Crs and FEV{sub 0.1}, indicating airway constriction in the control group. This airway constriction was significantly attenuated by MK-886, mepyramine, cromolyn sodium, and compound 48/80, but not by either methysergide or indomethacin. Both LTC{sub 4} and histamine infusion significantly increased the magnitude of CA-induced airway constriction in compound 48/80-pretreated guinea pigs. Citric acid inhalation caused significant increase in histamine level in the BAL sample, which was significantly suppressed by compound 48/80. These results suggest that leukotrienes and histamine originating from mast cells play an important role in CA inhalation-induced noncholinergic airway constriction.

  19. Immediate post-dosing paralysis following severe soman and VX toxicosis in guinea pigs.

    PubMed

    Bide, R W; Schofield, L; Risk, D J

    2005-01-01

    There have been numerous studies of the central nervous system (CNS) involvement in organophosphate (OP) poisoning showing status epilepticus and/or 'electrographic seizures'. Brain damage has been demonstrated as 'neuronal necrosis' primarily in the cortex, thalamus and hippocampus. To the authors' knowledge there have been no reports of partial/total paralysis following close upon OP exposure although delayed paralysis has been reported. This report summarizes the immediate, OP induced paralytic events recorded in guinea pigs during development of the Canadian reactive skin decontaminant lotion (RSDL). As part of the development work, supra-lethal cutaneous doses of OP were applied to large numbers of guinea pigs followed by decontamination with the RSDL or predecessor lotions and solvents. Soman (pinacolyl methylphosphonofluoridate; GD) challenges were applied to 1277 animals and S-(2-diisopropyl-aminoethyl) methylphosphorothiolate (VX) challenges to 108. The classic sequence of clinical signs--ptyalism, tremors, fasciculations, convulsions, apnea and flaccid paralysis before death--was seen in the 658 animals that died and in many of the survivors. Eighty-four of 688 survivors of GD and 4 of 39 survivors of VX showed random paralysis of various distal regions following recovery from an insult which produced convulsions and/or flaccid paralysis. Because the experiments were designed to assess the decontamination procedures, there were no apparent relationships between the amounts of OP applied and the sequellae recorded. The observations of paralysis were also incidental to the prime focus of the experiments. Because of this, only ten animals paralysed following GD exposure were examined for histological effects. The pathologist diagnosed 'encephalomalacia' and 'focal necrotic lesions' in the cerebral cortex and 'focal necrotic lesions' in one spinal cord. Of the 84 guinea pigs paralysed after GD challenge, one was not decontaminated and the decontaminants used

  20. Effect of memantine on cough reflex sensitivity: translational studies in guinea pigs and humans.

    PubMed

    Dicpinigaitis, Peter V; Canning, Brendan J; Garner, Rachel; Paterson, Blake

    2015-03-01

    Cough is the most common complaint for which outpatients in the United States seek medical attention, and yet available therapeutic options for cough lack proven efficacy and are further limited by safety and abuse liabilities. Thus, safe and effective cough suppressants are needed. Recent preclinical studies described the antitussive effects of memantine, an N-methyl-d-aspartate receptor channel blocker used in the treatment of Alzheimer's disease. The goals of the present study were to compare the antitussive effects of memantine, dextromethorphan, and codeine in guinea pigs; to relate the dose-dependent actions of memantine in these studies to peak plasma concentrations achieved following oral administration; and to provide the first ever evaluation of the antitussive effect of memantine in humans. In guinea pigs, memantine and codeine were comparable in efficacy and potency but both were superior to dextromethorphan in the citric acid cough challenge model. The pharmacokinetic analyses suggest that memantine was active in guinea pigs at micromolar plasma concentrations. Subsequently, 14 healthy volunteers as well as 14 otherwise healthy adults with acute viral upper respiratory tract infection (URI) underwent capsaicin cough challenges 6 hours after ingestion of 20 mg memantine and matched placebo in a randomized, double-blind, crossover fashion. In healthy volunteers, memantine significantly inhibited cough reflex sensitivity (P = 0.034). In subjects with URI, responsiveness to capsaicin was markedly increased, and in these patients, the inhibition of cough reflex sensitivity by memantine relative to placebo did not reach statistical significance (P = 0.088). These data support further research to investigate the potential of memantine as a clinically useful antitussive.

  1. Antitussive activity of sigma-1 receptor agonists in the guinea-pig.

    PubMed

    Brown, Claire; Fezoui, Malika; Selig, William M; Schwartz, Carl E; Ellis, James L

    2004-01-01

    1. Current antitussive medications have limited efficacy and often contain the opiate-like agent dextromethorphan (DEX). The mechanism whereby DEX inhibits cough is ill defined. DEX displays affinity at both NMDA and sigma receptors, suggesting that the antitussive activity may involve central or peripheral activity at either of these receptors. This study examined and compared the antitussive activity of DEX and various putative sigma receptor agonists in the guinea-pig citric-acid cough model. 2. Intraperitoneal (i.p.) administration of DEX (30 mg kg(-1)) and the sigma-1 agonists SKF-10,047 (1-5 mg kg(-1)), Pre-084 (5 mg kg(-1)), and carbetapentane (1-5 mg kg(-1)) inhibited citric-acid-induced cough in guinea-pigs. Intraperitoneal administration of a sigma-1 antagonist, BD 1047 (1-5 mg kg(-1)), reversed the inhibition of cough elicited by SKF-10,047. In addition, two structurally dissimilar sigma agonists SKF-10,047 (1 mg ml(-1)) and Pre-084 (1 mg ml(-1)) inhibited cough when administered by aerosol. 3. Aerosolized BD 1047 (1 mg ml(-1), 30 min) prevented the antitussive action of SKF-10,047 (5 mg kg(-1)) or DEX (30 mg kg(-1)) given by i.p. administration and, likewise, i.p. administration of BD 1047 (5 mg kg(-1)) prevented the antitussive action of SKF-10,047 given by aerosol (1 mg ml(-1)). 4. These results therefore support the argument that antitussive effects of DEX may be mediated via sigma receptors, since both systemic and aerosol administration of sigma-1 receptor agonists inhibit citric-acid-induced cough in guinea-pigs. While significant systemic exposure is possible with aerosol administration, the very low doses administered (estimated <0.3 mg kg(-1)) suggest that there may be a peripheral component to the antitussive effect.

  2. Inhaled large porous particles of capreomycin for treatment of tuberculosis in a guinea pig model.

    PubMed

    Garcia-Contreras, L; Fiegel, J; Telko, M J; Elbert, K; Hawi, A; Thomas, M; VerBerkmoes, J; Germishuizen, W A; Fourie, P B; Hickey, A J; Edwards, D

    2007-08-01

    Capreomycin is used for the treatment of multidrug-resistant tuberculosis (MDR-TB), but it is limited therapeutically by its severe side effects. The objectives of the present studies were (i) to design low-density porous capreomycin sulfate particles for efficient pulmonary delivery to improve local and systemic drug bioavailability and capacity to reduce the bacillary load in the lungs in a manner similar to that achieved with intramuscular injections; (ii) to determine pharmacokinetic parameters after pulmonary administration of these capreomycin particles; and (iii) to evaluate the efficacy of these particles in treating animals in a small-aerosol-inoculum guinea pig model of TB. Capreomycin particles were manufactured by spray drying and characterized in terms of size and drug content. Pharmacokinetic parameters were determined by noncompartmental methods with healthy guinea pigs after administration of capreomycin particles by insufflation. The efficacy of the particles was evaluated by histopathological analysis and in terms of wet organ weight and bacterial burden in TB-infected animals. Lungs of animals receiving a 14.5-mg/kg dose of capreomycin particles showed significantly lower wet weights and smaller bacterial burdens than those of animals receiving any other treatment. These results were supported by histopathological analysis. The feasibility of inhaling capreomycin in a novel powder form, with the ultimate objective of the treatment of MDR-TB, is demonstrated by pharmacokinetic and pharmacodynamic studies with guinea pigs. If applied to humans with MDR-TB, such a therapeutic approach might simplify drug delivery by eliminating injections and might reduce adverse effects through lowering the dose.

  3. Basolateral anion transport mechanisms underlying fluid secretion by mouse, rat and guinea-pig pancreatic ducts

    PubMed Central

    Fernández-Salazar, M Paz; Pascua, Patricia; Calvo, José Julián; López, María A; Case, R Maynard; Steward, Martin C; San Román, José I

    2004-01-01

    Fluid secretion by interlobular pancreatic ducts was determined by using video microscopy to measure the rate of swelling of isolated duct segments that had sealed following overnight culture. The aim was to compare the HCO3− requirement for secretin-evoked secretion in mouse, rat and guinea-pig pancreas. In mouse and rat ducts, fluid secretion could be evoked by 10 nm secretin and 5 μm forskolin in the absence of extracellular HCO3−. In guinea-pig ducts, however, fluid secretion was totally dependent on HCO3−. Forskolin-stimulated fluid secretion by mouse and rat ducts in the absence of HCO3− was dependent on extracellular Cl− and was completely inhibited by bumetanide (30 μm). It was therefore probably mediated by a basolateral Na+–K+–2Cl− cotransporter. In the presence of HCO3−, forskolin-stimulated fluid secretion was reduced ∼40% by bumetanide, ∼50% by inhibitors of basolateral HCO3− uptake (3 μm EIPA and 500 μm H2DIDS), and was totally abolished by simultaneous application of all three inhibitors. We conclude that the driving force for secretin-evoked fluid secretion by mouse and rat ducts is provided by parallel basolateral mechanisms: Na+–H+ exchange and Na+–HCO3− cotransport mediating HCO3− uptake, and Na+–K+–2Cl− cotransport mediating Cl− uptake. The absence or inactivity of the Cl− uptake pathway in the guinea-pig pancreatic ducts may help to account for the much higher concentrations of HCO3− secreted in this species. PMID:14978209

  4. Vigilance states, EEG spectra, and cortical temperature in the guinea pig.

    PubMed

    Tobler, I; Franken, P; Jaggi, K

    1993-06-01

    Vigilance states, electroencephalogram (EEG) power spectra (0.25-25.0 Hz), and cortical temperature (TCRT) were obtained in nine guinea pigs for 24 h in a 12:12-h light-dark (LD 12:12) schedule. Sleep was markedly polyphasic and fragmented and amounted to 32% of recording time, which is a low value compared with sleep in other rodents. There was 6.8% more sleep in the light period than in the dark period. EEG power density in non-rapid eye movement (NREM) sleep showed no significant temporal trend within the light or the dark period. The homeostatic aspects of sleep regulation, as proposed in the two-process model, can account for the slow-wave activity (SWA) pattern also in the guinea pig: The small 24-h amplitude of the sleep-wakefulness pattern resulted in a small, 12% decline of SWA within the light period. In contrast to more distinctly nocturnal rodents, SWA in the dark period was not higher than in the light period. TCRT showed no difference between the light and the dark period. TCRT in REM sleep and waking was higher than TCRT in NREM sleep. TCRT increased after the transition from NREM sleep to either REM sleep or waking, and decreased in the last minute before the transition and after the transition from waking to NREM sleep. Motor activity measured in six animals for 11 days in constant darkness showed no apparent rhythm in three animals and a significant circadian rhythm in three others. Our data support the notion that guinea pigs exhibit only a weak circadian rest-activity rhythm. PMID:8322965

  5. Lectin histochemistry of the gastric mucosa in normal and Helicobacter pylori infected guinea-pigs.

    PubMed

    Lueth, M; Sturegård, E; Sjunnesson, H; Wadström, T; Schumacher, U

    2005-02-01

    Helicobacter pylori attaches via lectins, carbohydrate binding proteins, to the carbohydrate residues of gastric mucins. Guinea-pigs are a suitable model for a H. pylori infection and thus the carbohydrate composition of normal and H. pylori infected gastric mucosa was investigated by lectin histochemistry. The stomach of all infected animals showed signs of an active chronic gastritis in their mucosa, whereas no inflammation was present in the control animals. The corpus-fundus regions of the controls showed heterogeneous WGA, SNA-I, UEA-I and HPA binding in almost all parts of the gastric glands. While these lectins labelled the superficial mucous cells and chief cells heterogeneously, the staining of the parietal cells was limited to WGA and PHA-L. Mucous neck cells reacted heterogeneously with UEA-I, HPA, WGA and PHA-L. In the antrum, the superficial mucous cells and glands were stained by WGA, UEA-I, HPA, SNA-I or PHA-L. WGA, UEA-I, SNA-I and HPA labelled the surface lining cells strongly. The mucoid glands reacted heterogeneously with WGA, UEA-I, HPA, SNA-I and PHA-L. In both regions, the H. pylori infected animals showed similar lectin binding pattern as the controls. No significant differences in the lectin binding pattern and thus in the carbohydrate composition between normal and H. pylori infected mucosa could be detected, hence H. pylori does not induce any changes in the glycosylation of the mucosa of the guinea-pig. This unaltered glycosylation is of particular relevance for the sialic acid binding lectin SNA-I as H. pylori uses sialic acid binding adhesin for its attachment to the mucosa. As sialic acid binding sites are already expressed in the normal mucosa H. pylori can immediately attach via its sialic acid binding adhesin to the mucosa making the guinea-pig particularly useful as a model organism.

  6. Arachidonic acid metabolites do not mediate toluene diisocyanate-induced airway hyperresponsiveness in guinea pigs

    SciTech Connect

    Gordon, T.; Thompson, J.E.; Sheppard, D.

    1988-05-01

    Arachidonic acid metabolites have previously been demonstrated to mediate the airway hyperresponsiveness observed in guinea pigs and dogs after exposure to ozone. Guinea pigs were treated with indomethacin (a cyclooxygenase inhibitor), U-60,257 (piriprost, a 5-lipoxygenase inhibitor), or BW775c (a lipoxygenase and cyclooxygenase inhibitor) and exposed to air or 3 ppm TDI. Airway responsiveness to acetylcholine aerosol was examined 2 h after exposure. In control animals, the provocative concentration of acetylcholine which caused a 200% increase in pulmonary resistance over baseline (PC200) was significantly less (p less than 0.05) after exposure to TDI (8.6 +/- 2.0 mg/ml, geometric mean + geometric SE, n = 10) than after exposure to air (23.9 + 2.5 mg/ml, n = 14). The airway responsiveness to acetylcholine in animals treated with indomethacin or piriprost and exposed to TDI was not different from that of control animals exposed to TDI. Treatment with BW755c enhanced the airway hyperresponsiveness observed in animals exposed to TDI without altering the PC200 of animals exposed to air. The PC200 of animals treated with BW755c and exposed to TDI (2.3 + 0.8 mg/ml, n = 8) was significantly lower than the PC200 of control animals exposed to TDI (p less than 0.025). These results suggest that products of arachidonic acid metabolism are not responsible for TDI-induced airway hyperresponsiveness in guinea pigs. BW755c, however, appears to potentiate the TDI-induced airway hyperresponsiveness to acetylcholine by an as yet unidentified mechanism.

  7. Efficacy of the investigational echinocandin ASP9726 in a guinea pig model of invasive pulmonary aspergillosis.

    PubMed

    Wiederhold, Nathan P; Najvar, Laura K; Matsumoto, Satoru; Bocanegra, Rosie A; Herrera, Monica L; Wickes, Brian L; Kirkpatrick, William R; Patterson, Thomas F

    2015-05-01

    ASP9726 is an investigational echinocandin with in vitro activity against Aspergillus species. We evaluated the pharmacokinetics and efficacy of this agent in an established guinea pig model of invasive pulmonary aspergillosis. ASP9726 plasma concentrations were measured in guinea pigs administered either a single dose or multiple doses of this agent at 2.5, 5, and 10 mg/kg of body weight/day by subcutaneous injection. Immunosuppressed guinea pigs were inoculated with A. fumigatus AF293, and ASP9726 (2.5, 5, and 10 mg/kg/day), voriconazole (10 mg/kg by oral gavage twice daily), or caspofungin (3 mg/kg/day by intraperitoneal injection) was administered for 8 days. Changes in fungal burden were measured by enumerating CFU and by quantitative PCR of specimens from within the lungs, as well as by analysis of serum (1 → 3)-β-D-glucan and galactomannan. Lung histopathology was also evaluated. ASP9726 plasma concentrations increased in a dose-proportional manner, and the drug was well tolerated at each dose. Each dose of ASP9726, voriconazole, and caspofungin significantly reduced pulmonary fungal burden as measured by quantitative PCR and by determining (1 → 3)-β-D-glucan and galactomannan levels, but only voriconazole significantly reduced numbers of CFU. ASP9726 at 5 mg/kg also significantly improved survival. Histopathology demonstrated morphological changes in hyphae in animals exposed to ASP9726 and caspofungin, consistent with the activities of the echinocandins. These results suggest that ASP9726 may be efficacious for the treatment of invasive pulmonary aspergillosis. PMID:25753643

  8. Acute respiratory toxicity following inhalation exposure to soman in guinea pigs

    SciTech Connect

    Perkins, Michael W.; Pierre, Zdenka; Rezk, Peter; Sabnekar, Praveena; Sciuto, Alfred M.; Nambiar, Madhusoodana P.

    2010-06-01

    Respiratory toxicity and lung injury following inhalation exposure to chemical warfare nerve agent soman was examined in guinea pigs without therapeutics to improve survival. A microinstillation inhalation exposure technique that aerosolizes the agent in the trachea was used to administer soman to anesthetized age and weight matched male guinea pigs. Animals were exposed to 280, 561, 841, and 1121 mg/m{sup 3} concentrations of soman for 4 min. Survival data showed that all saline controls and animals exposed to 280 and 561 mg/m{sup 3} soman survived, while animals exposed to 841, and 1121 mg/m{sup 3} resulted in 38% and 13% survival, respectively. The microinstillation inhalation exposure LCt{sub 50} for soman determined by probit analysis was 827.2 mg/m{sup 3}. A majority of the animals that died at 1121 mg/m{sup 3} developed seizures and died within 15-30 min post-exposure. There was a dose-dependent decrease in pulse rate and blood oxygen saturation of animals exposed to soman at 5-6.5 min post-exposure. Body weight loss increased with the dose of soman exposure. Bronchoalveolar lavage (BAL) fluid and blood acetylcholinesterase and butyrylcholinesterase activity was inhibited dose-dependently in soman treated groups at 24 h. BAL cells showed a dose-dependent increase in cell death and total cell counts following soman exposure. Edema by wet/dry weight ratio of the accessory lung lobe and trachea was increased slightly in soman exposed animals. An increase in total bronchoalveolar lavage fluid protein was observed in soman exposed animals at all doses. Differential cell counts of BAL and blood showed an increase in total lymphocyte counts and percentage of neutrophils. These results indicate that microinstillation inhalation exposure to soman causes respiratory toxicity and acute lung injury in guinea pigs.

  9. Neurogenic and myogenic motor activity in the colon of the guinea pig, mouse, rabbit, and rat.

    PubMed

    Costa, M; Dodds, K N; Wiklendt, L; Spencer, N J; Brookes, S J H; Dinning, P G

    2013-11-15

    Gastrointestinal motility involves interactions between myogenic and neurogenic processes intrinsic to the gut wall. We have compared the presence of propagating myogenic contractions of the isolated colon in four experimental animals (guinea pig, mouse, rabbit, and rat), following blockade of enteric neural activity. Isolated colonic preparations were distended with fluid, with the anal end either closed or open. Spatiotemporal maps of changes in diameter were constructed from video recordings. Distension-induced peristaltic contractions were abolished by tetrodotoxin (TTX; 0.6 μM) in all animal species. Subsequent addition of carbachol (0.1-1 μM) did not evoke myogenic motor patterns in the mouse or guinea pig, although some activity was observed in rabbit and rat colon. These myogenic contractions propagated both orally and anally and differed from neurogenic propagating contractions in their frequency, extent of propagation, and polarity. Niflumic acid (300 μM), used to block myogenic activity, also blocked neural peristalsis and thus cannot be used to discriminate between these mechanisms. In all species, except the mouse colon, small myogenic "ripple" contractions were revealed in TTX, but in both rat and rabbit an additional, higher-frequency ripple-type contraction was superimposed. Following blockade of enteric nerve function, a muscarinic agonist can evoke propulsive myogenic peristaltic contractions in isolated rabbit and rat colon, but not in guinea pig or mouse colon. Marked differences between species exist in the ability of myogenic mechanisms to propel luminal content, but in all species there is normally a complex interplay between neurogenic and myogenic processes.

  10. Repeated low-dose exposures to sarin, soman, or VX affect acoustic startle in guinea pigs.

    PubMed

    Smith, C D; Lee, R B; Moran, A V; Sipos, M L

    2016-01-01

    Chemical warfare nerve agents (CWNAs) are known to cause behavioral abnormalities in cases of human exposures and in animal models. The behavioral consequences of single exposures to CWNAs that cause observable toxic signs are particularly well characterized in animals; however, less is known regarding repeated smaller exposures that may or may not cause observable toxic signs. In the current study, guinea pigs were exposed to fractions (0.1, 0.2, or 0.4) of a medial lethal dose (LD50) of sarin, soman, or VX for two weeks. On each exposure day, and for a post-exposure period, acoustic startle response (ASR) was measured in each animal. Although relatively few studies use guinea pigs to measure behavior, this species is ideal for CWNA-related experiments because their levels of carboxylesterases closely mimic those of humans, unlike rats or mice. Results showed that the 0.4 LD50 doses of soman and VX transiently increased peak startle amplitude by the second week of injections, with amplitude returning to baseline by the second week post-exposure. Sarin also increased peak startle amplitude independent of week. Latencies to peak startle and PPI were affected by agent exposure but not consistently among the three agents. Most of the changes in startle responses returned to baseline following the cessation of exposures. These data suggest that doses of CWNAs not known to produce observable toxic signs in guinea pigs can affect behavior in the ASR paradigm. Further, these deficits are transient and usually return to baseline shortly after the end of a two-week exposure period. PMID:26829110

  11. Existence of three subtypes of bradykinin B2 receptors in guinea pig.

    PubMed

    Seguin, L; Widdowson, P S; Giesen-Crouse, E

    1992-12-01

    We describe the binding of [3H]bradykinin to homogenates of guinea pig brain, lung, and ileum. Analysis of [3H]bradykinin binding kinetics in guinea pig brain, lung, and ileum suggests the existence of two binding sites in each tissue. The finding of two binding sites for [3H]bradykinin in ileum, lung, and brain was further supported by Scatchard analysis of equilibrium binding in each tissue. [3H]Bradykinin binds to a high-affinity site in brain, lung, and ileum (KD = 70-200 pM), which constitutes approximately 20% of the bradykinin binding, and to a second, lower-affinity site (0.63-0.95 nM), which constitutes the remaining 80% of binding. Displacement studies with various bradykinin analogues led us to subdivide the high- and lower-affinity sites in each tissue and to suggest the existence of three subtypes of B2 receptors in the guinea pig, which we classify as B2a, B2b, and B2c. Binding of [3H]bradykinin is largely to a B2b receptor subtype, which constitutes the majority of binding in brain, lung, and ileum and represents the lower-affinity site in our binding studies. Receptor subtype B2c constitutes approximately 20% of binding sites in the brain and lung and is equivalent to the high-affinity site in brain and lung. We suggest that a third subtype of B2 receptor (high-affinity site in ileum), B2a, is found only in the ileum. All three subtypes of B2 receptors display a high affinity for bradykinin, whereas they show different affinities for various bradykinin analogues displaying agonist or antagonist activities.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Spontaneous osteoarthritis in Dunkin Hartley guinea pigs: histologic, radiologic, and biochemical changes.

    PubMed

    Jimenez, P A; Glasson, S S; Trubetskoy, O V; Haimes, H B

    1997-12-01

    Dunkin Hartley guinea pigs develop spontaneous, age-related osteoarthritis (OA) of the knee and other joints. Histologic changes are observed beginning at 3 months of age. Disease severity increases with age, and at 18 months moderate to severe OA is observed. A study was undertaken to assess the morphologic and biochemical changes of 22-month-old animals, and to compare them with values in 2-month-old guinea pigs. Biochemical indices characteristic of OA, from tibial cartilage, indicated an increase in proteoglycan content from 233 +/- 2 micrograms/mg (mean +/- SEM) at 2 months of age to 365 +/- 6 micrograms/mg at 22 months. Collagen concentration in cartilage decreased from 364 +/- 2 micrograms/mg at 2 months to 223 +/- 3 micrograms/mg at 22 months. Proteoglycan fragments found in synovial fluid measured 4.6 +/- 1 micrograms/ml at 2 months and increased to 37 +/- 2 micrograms/ml at 22 months. Radiographic changes observed at 22 months included marginal osteophytes of the tibia and femur, sclerosis of the subchondral bone of the tibial plateau, femoral condyle cysts, and calcification of the collateral ligaments. Histologic evaluation revealed severe OA, with a Mankin score of 10.7 +/- 0.5 in 22-month-old animals. In contrast, 2-month-old animals had no histologic or radiographically detectable lesions. The results of the study reported here indicate that the lesions observed in this model are similar to those of human OA. Spontaneous development of OA in guinea pigs is amenable to the study of the pathogenesis of OA and to the evaluation of potential disease-modifying agents.

  13. Non-diabetic hyperglycemia exacerbates disease severity in Mycobacterium tuberculosis infected guinea pigs.

    PubMed

    Podell, Brendan K; Ackart, David F; Kirk, Natalie M; Eck, Sarah P; Bell, Christopher; Basaraba, Randall J

    2012-01-01

    Hyperglycemia, the diagnostic feature of diabetes also occurs in non-diabetics associated with chronic inflammation and systemic insulin resistance. Since the increased risk of active TB in diabetics has been linked to the severity and duration of hyperglycemia, we investigated what effect diet-induced hyperglycemia had on the severity of Mycobacterium tuberculosis (Mtb) infection in non-diabetic guinea pigs. Post-prandial hyperglycemia was induced in guinea pigs on normal chow by feeding a 40% sucrose solution daily or water as a carrier control. Sucrose feeding was initiated on the day of aerosol exposure to the H37Rv strain of Mtb and continued for 30 or 60 days of infection. Despite more severe hyperglycemia in sucrose-fed animals on day 30, there was no significant difference in lung bacterial or lesion burden until day 60. However the higher spleen and lymph node bacterial and lesion burden at day 30 indicated earlier and more severe extrapulmonary TB in sucrose-fed animals. In both sucrose- and water-fed animals, serum free fatty acids, important mediators of insulin resistance, were increased by day 30 and remained elevated until day 60 of infection. Hyperglycemia mediated by Mtb infection resulted in accumulation of advanced glycation end products (AGEs) in lung granulomas, which was exacerbated by sucrose feeding. However, tissue and serum AGEs were elevated in both sucrose and water-fed guinea pigs by day 60. These data indicate that Mtb infection alone induces insulin resistance and chronic hyperglycemia, which is exacerbated by sucrose feeding. Moreover, Mtb infection alone resulted in the accumulation tissue and serum AGEs, which are also central to the pathogenesis of diabetes and diabetic complications. The exacerbation of insulin resistance and hyperglycemia by Mtb infection alone may explain why TB is more severe in diabetics with poorly controlled hyperglycemia compared to non-diabetics and patients with properly controlled blood glucose levels.

  14. Nerve-epithelium association in the periodontal ligament of guinea pig teeth.

    PubMed

    Jayawardena, Chantha K; Takano, Yoshiro

    2006-07-01

    Several lines of evidence have suggested that periodontal nerves have other roles besides sensory function. Exploring the distribution pattern of nerves in relation to other structures within the periodontal ligament of various species should be important to understand their roles within the ligament. This study investigated whether any association exists between the nerves and the epithelial cells in the periodontal ligament of continuously erupting guinea pig molars, which show distinct enamel epithelium layers among the cementum pearls. Ten guinea pigs were fixed by vascular perfusion and jaw sections were processed for immunohistochemistry of protein gene product 9.5 (PGP 9.5), growth-associated protein-43 (GAP-43) and glia-specific S-100 protein, and for enzyme histocytochemistry of cholinesterase. Nerves that were immunopositive for the above neuronal markers were located predominantly in the alveolus-related part of the periodontal ligament. Some nerves, immunoreactive for PGP 9.5 and GAP-43, were also found in the tooth-related part (TRP) of the periodontal ligament close to the tooth surface. PGP 9.5-positive nerves in the TRP appeared very thin and terminated by making loops or plexus-like structures in close apposition to the epithelium layers, overlying the enamel surface in between cementum pearls. Such an intimate association between nerves and the enamel epithelium was not found in the labial periodontal tissue of incisors or the apical growing end of the molar, where periodontal fibre attachment was indistinct. The association between nerves and epithelium in the periodontal ligament of guinea pig molar is site specific and is only seen in the presence of cementum, suggesting that this association is related to the attachment function of the ligament. PMID:16510117

  15. Organophosphorus Pesticides Decrease M2 Muscarinic Receptor Function in Guinea Pig Airway Nerves via Indirect Mechanisms

    PubMed Central

    Proskocil, Becky J.; Bruun, Donald A.; Thompson, Charles M.; Fryer, Allison D.; Lein, Pamela J.

    2010-01-01

    Background Epidemiological studies link organophosphorus pesticide (OP) exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE) inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on peripheral neurons via similar direct mechanisms. Methodology/Principal Findings Intravenous administration of paraoxon, but not parathion, caused acute frequency-dependent potentiation of vagally-induced bronchoconstriction and increased electrical field stimulation (EFS)-induced contractions in isolated trachea independent of AChE inhibition. However, paraoxon had no effect on vagally-induced bradycardia in intact guinea pigs or EFS-induced contractions in isolated ileum, suggesting mechanisms other than pharmacologic antagonism of M2 receptors. Paraoxon did not alter M2 receptor expression in cultured cells at the mRNA or protein level as determined by quantitative RT-PCR and radio-ligand binding assays, respectively. Additionally, a biotin-labeled fluorophosphonate, which was used as a probe to identify molecular targets phosphorylated by OPs, did not phosphorylate proteins in guinea pig cardiac membranes that were recognized by M2 receptor antibodies. Conclusions/Significance These data indicate that neither direct pharmacologic antagonism nor downregulated expression of M2 receptors contributes to OP inhibition of M2 function in airway nerves, adding to the growing evidence of non-cholinergic mechanisms of OP neurotoxicity. PMID:20479945

  16. Modulation of experimental autoimmune uveitis with formosanin-C in guinea pigs.

    PubMed

    Wu, R T; Lin, W J; Chiang, H C; Horng, L Y; Chung, Y M

    1990-01-01

    Formosanin-C, a diosgenin saponin, was isolated from a perennial herb, Paris formosana Hayata (Liliaceae) which has been used as a folk remedy for snake bite and as an anti-inflammatory or anti-neoplastic agent. Its effect on the development of S-antigen-induced experimental autoimmune uveitis (EAU) in guinea pigs was studied. Guinea pigs treated with formosanin-C (1.5 mg/kg/2 days and 0.5 mg/kg/2 days) were compared with untreated guinea pigs in regard to the development of EAU, lymphocytic proliferative responses, and anti-S-antigen serum antibodies. The higher dosage of formosanin-C (1.5 mg/kg) obviously delayed the onset of EAU. Treatment of this drug, 1.5 mg/kg and 0.5 mg/kg doses, significantly inhibited the specific lymphocytic response of lymph node and spleen cells to S-antigen. On the contrary, treatment in 1.5 mg/kg dose significantly increased the response of lymph node and spleen cells to the polyclonal T cell mitogen, phytohemagglutinin (PHA). Treatment with formosanin-C in both the 1.5 mg/kg and 0.5 mg/kg doses had a minimal effect on the lymphocytic response of lymph node to concanavalin-A (ConA), while a noticeable suppressive effect on the response of spleen cells to ConA was observed in the 1.5 mg/kg dose. This agent in 1.5 mg/kg and 0.5 mg/kg doses significantly inhibited the anti-S-antigen antibody production by days 14 and 18 postimmunization. This study suggests that formosanin-C, an immunomodulator, may offer a new approach to modulate the development of EAU. PMID:2097314

  17. Tonic eye movements induced by bilateral and unilateral galvanic vestibular stimulation (GVS) in guinea pigs.

    PubMed

    Kim, Juno

    2013-01-01

    Galvanic vestibular stimulation (GVS) stimulates primary vestibular afferents innervating the semicircular canals (SCCs) and otoliths found in the inner ear of humans and other mammals, including guinea pigs. To determine which pathways contribute to eye movements generated by this artificial vestibular stimulation in guinea pigs, low current intensities of GVS were passed either bilaterally between the tensor-tympani muscles of the two ears (up to 30 μA) or unilaterally between one tensor-tympani electrode and an indifferent on the back of the neck (up to 60 μA). Both forms of GVS were found to selectively generate tonic eye movements without nystagmus, characteristic of the otolith-ocular reflex; the axis of eye rotation did not align with any semicircular canal plane, but was oriented close to the expected axis of eye rotation that would occur in response to the net stimulation of otolith afferents. The induced eye rotation was predominantly vertical with a smaller horizontal deviation and very little torsion. Consistent with the results of previous human studies, the tonic eye movements were found to exhibit bilateral gain enhancement, whereby bilateral GVS generated twice the amplitude of eye rotation as unilateral anodal or cathodal stimulation alone. Eye movement responses to unilateral GVS were symmetrical in amplitude during equivalent intensities of anodal and cathodal stimulation, consistent with the known responses of more regularly and intermediately discharging primary vestibular afferents to GVS. These results together suggest that more regularly discharging otolith-ocular projections may mediate the tonic changes in eye position induced during maintained, low-intensity GVS in guinea pigs.

  18. Effects of Eszopiclone and Zolpidem on Sleep and Waking States in the Adult Guinea Pig

    PubMed Central

    Xi, Mingchu; Chase, Michael H.

    2008-01-01

    Study Objective: The present study was designed to compare and contrast the effects of eszopiclone and zolpidem on the states of sleep and wakefulness in chronically instrumented, unanesthetized adult guinea pigs. Design: Adult guinea pigs were implanted with electrodes to record sleep and waking states and to perform a frequency analysis of the EEG. Eszopiclone (1 and 3 mg/kg) and zolpidem (1 and 3 mg/kg) were administered intraperitoneally. Measurements and Results: The administration of eszopiclone (1 and 3 mg/kg) resulted in a significant dose-dependent increase in NREM sleep. Zolpidem produced a significant increase in NREM sleep, but only at a dose of 3 mg/kg. The following changes in NREM and REM sleep, as well as in the power spectra, were all significant when the effects of 1 and 3 mg/kg of eszopiclone were compared with responses induced with 1 and 3 mg/kg of zolpidem, respectively: The increase in NREM sleep produced by eszopiclone was greater than that following the administration of zolpidem. The mean latency to NREM sleep following the administration of eszopiclone was significantly shorter than zolpidem. Eszopiclone significantly increased the latency to REM sleep. The mean duration of episodes of NREM sleep was increased by eszopiclone, but not by zolpidem. The EEG power increased in the delta band and decreased in the theta band during NREM sleep following the administration of eszopiclone. No significant changes occurred in any of the frequency bands analyzed following zolpidem administration. Conclusions: The differences in the effects of eszopiclone and zolpidem on sleep and waking states and the power spectra of the EEG likely reflect the fact that eszopiclone and zolpidem bind to different subunits of the GABAA receptor complex. Citation: Xi M; Chase MH. Effects of eszopiclone and zolpidem on sleep and waking states in the adult guinea pig. SLEEP 2008;31(7):1043-1051. PMID:18652100

  19. Functional differences between the outer and inner zones of the guinea pig adrenal cortex

    SciTech Connect

    Strott, C.A.; Goff, A.K.; Lyons, C.D.

    1981-12-01

    The guinea pig adrenal cortex is grossly composed of two regions: an outer, yellow zone and an inner, brown zone. These zones, which represent 33% and 66% of the total adrenocortical volume, respectively, can be separated by blunt dissection. It has been previously reported that specific pregnenolone and pregnenolone sulfate binding proteins are present in the high speed supernatant fraction (cytosol) prepared from the whole adrenal cortex of the guinea pig. However, when cytosol was prepared from the separate outer and inner cortical zones, it was found that the steroid-binding proteins were concentrated in the inner zone. This correlated with the level of pregnenolone which was significantly greater in the cytosol of the inner zone where greater than 50% was found to be bound. In contrast, the concentration of cortisol was 30 times greater in the cytosol of the outer cortical zone and less than 4% was found to be bound. These data suggest that cortisol is produced primarily in the outer cortical zone, a region which comprises only one-third of the total cortical volume. On the other hand, the coexistence of pregnenolone and its binding protein in the inner cortical zone, a region which comprises two-thirds or the greatest cortical volume, indicates a different functional status for this zone. The exact hormonal control of these two vastly different regions (chromatically, morphologically, and functionally) remains to be determined. It is speculated that the inner cortical zone of the adult guinea pig adrenal is the counterpart of the fetal cortex which did not involute.

  20. O3-induced mucosa-linked airway muscle hyperresponsiveness in the guinea pig

    SciTech Connect

    Murlas, C.G.; Murphy, T.P.; Chodimella, V. )

    1990-07-01

    We investigated the effects of ozone exposure (3.0 ppm, 2 h) on the responsiveness of guinea pig airway muscle in vitro from animals developing bronchial hyperreactivity. Muscarinic reactivity in vivo was determined by measuring specific airway resistance (sRaw) in response to increasing concentrations of aerosolized acetylcholine (ACh) administered before and 30 min after exposure. Immediately after reactivity testing, multiple tracheal rings from ozone- and air-exposed animals were prepared and the contractile responses to increasing concentrations of substance P, ACh, or KCl were assessed in the presence of 10 microM indomethacin with or without 1 microM phosphoramidon, an inhibitor of neutral endopeptidase. Isometric force generation in vitro was measured on stimulation by cumulative concentrations of the agonists, and force generation (in g/cm2) was calculated after determination of muscle cross-sectional area. The smooth muscle of mucosa-intact airways from guinea pigs with ozone-induced bronchial hyper-reactivity proved to be hyperresponsive in vitro to substance P and ACh but not to KCl. Pretreatment with phosphoramidon abolished the increase in substance P responsiveness but had no effect on muscarinic hyperresponsiveness after ozone exposure. Furthermore, substance P responsiveness was not augmented in ozone-exposed airways in which the mucosa had been removed before testing in vitro. Likewise, muscarinic hyperresponsiveness was not present in ozone-exposed airways without mucosa. Our data indicate that airway smooth muscle responsiveness is increased in guinea pigs with ozone-induced bronchial hyperreactivity and suggest that this hyperresponsiveness may be linked to non-cyclooxygenase mucosa-derived factors.

  1. The actions of isoprenaline and mirabegron in the isolated whole rat and guinea pig bladder.

    PubMed

    Persyn, Sara; De Wachter, Stefan; Wyndaele, Jean-Jacques; Eastham, Jane; Gillespie, James

    2016-07-01

    β3-adrenoceptor agonists influence overactive bladder in humans and animal models. However, data is emerging that the mode of action of these drugs is complex. The present study explored the actions of the β3-adrenergic agonist mirabegron and the non-selective agonist isoprenaline on the contractile systems in the rat and guinea pig bladder. Intravesical pressure was measured in isolated whole bladders from female adult animals. In both species spontaneous contractile activity was observed. The muscarinic agonist arecaidine produced complex responses consisting of an initial transient pressure rise followed by complex phasic activity. Three contractile elements were identified: intrinsic micro-contractile activity, initial transient response and steady state phasic activity. The intrinsic and steady state activity could be further divided into a baseline pressure with superimposed phasic activity. The effects of isoprenaline and mirabegron were investigated on these elements. In the rat, the micro-contractile activity could be completely inhibited by isoprenaline (full agonist). The arecaidine-induced initial and steady state baseline pressures were partially reduced, while the phasic activity was little affected. In the guinea pig, both the arecaidine-induced baseline pressure and the phasic activity were affected by isoprenaline. Mirabegron didn't produce significant inhibitory effects in any of the contractile elements in either species. These results show that complex contractile systems operate in the rat and guinea pig bladder that can be modulated by β1/β2-adrenoceptor mechanisms. No evidence was obtained for any β3-dependent regulation of contraction. These data support similar data in humans. Therefore the primary site of therapeutic action of β3-adrenergic agonists remains unknown.

  2. Heat-killed Corynebacterium parvum enhances endotoxin lung injury with increased TNF production in guinea pigs.

    PubMed

    Tasaka, S; Ishizaka, A; Sayama, K; Sakamaki, F; Nakamura, H; Terashima, T; Waki, Y; Soejima, K; Nakamura, M; Matsubara, H; Fujishima, S; Kanazawa, M

    1996-03-01

    Corynebacterium parvum (CP) is known to increase susceptibility to endotoxin, which is associated with increased production of tumor necrosis factor (TNF). We investigated the effect of CP-priming on the pathogenesis of acute lung injury caused by intratracheal Escherichia coli endotoxin (lipopolysaccharide [LPS]). Guinea pigs were divided into four groups: (1) control (n=6), (2) CP-alone (n=6), (3) LPS-alone (n=6) and (4) CP + LPS (n=6). A CP dose of 4 mg/kg was injected intraperitoneally 7 d before the study. Animals were observed for 4 h after intratracheal administration of 0.02 mg/kg of LPS. The lung wet-to-dry weight ratio (W/D), [125I] albumin concentration ratio of lung tissue to plasma (T/P) and of bronchoalveolar lavage (BAL) fluid to plasma (B/P) and differential cell count in BAL fluid were examined. In the LPS-alone group, neither excess lung water nor increased albumin leakage was observed. The CP + LPS group showed increased lung water and albumin leakage as compared with the other three groups (p<0.05). We also observed increased cell counts in BAL fluid (p<0.05), in the CP + LPS group. The spleen weight was increased in guinea pigs pretreated with CP, indicating reticuloendothelial system (RES) activation. In the CP + LPS group, the TNF level was increased in both plasma and BAL fluid. We conclude that pretreatment with CP enhances LPS-induced acute lung injury in parallel with increasing TNF production, which suggests that the activation of mononuclear phagocytes contributes to increased susceptibility to intratracheal endotoxin in guinea pigs. PMID:8630544

  3. SLC26 anion exchangers of guinea pig pancreatic duct: molecular cloning and functional characterization

    PubMed Central

    Stewart, Andrew K.; Shmukler, Boris E.; Vandorpe, David H.; Reimold, Fabian; Heneghan, John F.; Nakakuki, M.; Akhavein, Arash; Ko, Shigeru; Ishiguro, Hiroshi

    2011-01-01

    The secretin-stimulated human pancreatic duct secretes HCO3−-rich fluid essential for normal digestion. Optimal stimulation of pancreatic HCO3− secretion likely requires coupled activities of the cystic fibrosis transmembrane regulator (CFTR) anion channel and apical SLC26 Cl−/HCO3− exchangers. However, whereas stimulated human and guinea pig pancreatic ducts secrete ∼140 mM HCO3− or more, mouse and rat ducts secrete ∼40–70 mM HCO3−. Moreover, the axial distribution and physiological roles of SLC26 anion exchangers in pancreatic duct secretory processes remain controversial and may vary among mammalian species. Thus the property of high HCO3− secretion shared by human and guinea pig pancreatic ducts prompted us to clone from guinea pig pancreatic duct cDNAs encoding Slc26a3, Slc26a6, and Slc26a11 polypeptides. We then functionally characterized these anion transporters in Xenopus oocytes and human embryonic kidney (HEK) 293 cells. In Xenopus oocytes, gpSlc26a3 mediated only Cl−/Cl− exchange and electroneutral Cl−/HCO3− exchange. gpSlc26a6 in Xenopus oocytes mediated Cl−/Cl− exchange and bidirectional exchange of Cl− for oxalate and sulfate, but Cl−/HCO3− exchange was detected only in HEK 293 cells. gpSlc26a11 in Xenopus oocytes exhibited pH-dependent Cl−, oxalate, and sulfate transport but no detectable Cl−/HCO3− exchange. The three gpSlc26 anion transporters exhibited distinct pharmacological profiles of 36Cl− influx, including partial sensitivity to CFTR inhibitors Inh-172 and GlyH101, but only Slc26a11 was inhibited by PPQ-102. This first molecular and functional assessment of recombinant SLC26 anion transporters from guinea pig pancreatic duct enhances our understanding of pancreatic HCO3− secretion in species that share a high HCO3− secretory output. PMID:21593449

  4. Biological and physiocochemical properties of purified anti-DNP guinea-pig non-precipitating antibodies

    PubMed Central

    Margni, R. A.; Hajos, Silvia

    1973-01-01

    Methods for isolation and purification of precipitating and non-precipitating guinea-pig antibodies are described. The physicochemical properties of γ1 and γ2 non-precipitating antibodies are similar to γ1 and γ2 precipitating ones. Biological properties are also similar excepting the reverse Arthus reaction, which is positive with the precipitating and negative with the non-precipitating antibodies. Bivalence of these antibodies was experimentally demonstrated. Precipitating antibodies K0 do not differ greatly from those obtained with the corresponding non-precipitating ones. The incapacity to precipitates with the antigen may be a consequence of a steric impediment. ImagesFIG. 1 PMID:4267511

  5. Preliminary report on the influence of an argon laser on electrophysiology of cochlea in guinea pigs

    NASA Astrophysics Data System (ADS)

    Michalski, Wojciech; Dziewiszek, Wojciech

    1997-10-01

    A small electrical potential generated by cochlear, when the ear is stimulated by sound, has been used to estimate the influence of the argon laser on cochlear activity in guinea pigs. The detected potentials were recorded prior to, during and after laser irradiation of bone of cochlear, Laser pulses of 0.5-1 s duration and peak power of 100-660 mW were used in the experiment. The number of pulses in the series and the time interval between single laser pulses were varied, too. Depending on the laser irradiation parameters the values of CM returned or no to the pre-impact value.

  6. Experimental joint immobilization in guinea pigs. Effects on the knee joint

    NASA Technical Reports Server (NTRS)

    Marcondesdesouza, J. P.; Machado, F. F.; Sesso, A.; Valeri, V.

    1980-01-01

    In young and adult guinea pigs, the aftermath experimentally induced by the immobilization of the knee joint in hyperextended forced position was studied. Joint immobilization which varied from one to nine weeks was attained by plaster. Eighty knee joints were examined macro and microscopically. Findings included: (1) muscular hypotrophy and joint stiffness in all animals, directly proportional to the length of immobilization; (2) haemoarthrosis in the first week; (3) intra-articular fibrous tissue proliferation ending up with fibrous ankylosis; (4) hyaline articular cartilage erosions; (5) various degrees of destructive menisci changes. A tentative explanation of the fibrous tissue proliferation and of the cartilage changes is offered.

  7. Placental transfer of a large angiotensin fragment in the guinea pig.

    PubMed

    Broughton Pipkin, F; Benjamin, N; Macallan, C

    1977-08-15

    Angiotensin II (AII) levels are usually higher in the fetal than in the maternal circulations. Radioiodinated AII has been used to establish whether or not this hormone crosses the placenta from the fetus to the mother in the pregnant guinea pig. No intact radioiodinated AII was found to have crossed in any of 13 experiments. A single radioiodinated AII fragment was found in 10 of these experiments. This ran as (des-(Asp1 Arg2 Val3)) in one solvent, but this could not be confirmed when a different solvent was used. The results support the hypothesis, previously based on indirect evidence, that AII does not cross the placenta.

  8. Identification of both NK1 and NK2 receptors in guinea-pig airways.

    PubMed Central

    McKee, K. T.; Millar, L.; Rodger, I. W.; Metters, K. M.

    1993-01-01

    1. NK1 and NK2 receptors have been characterized in guinea-pig lung membrane preparations by use of [125I-Tyr8]-substance P and [125I]-neurokinin A binding assays in conjunction with tachykinin-receptor selective agonists ([Sar9Met(O2)11]substance P for NK1 and [beta Ala8]neurokinin A (4-10) for NK2) and antagonists (CP-99,994 for NK1 and SR48968 for NK2). 2. The presence of high affinity, G-protein-coupled NK1 receptors in guinea-pig lung parenchymal membranes has been confirmed. The rank order of affinity for competing tachykinins was as predicted for an NK1 receptor: substance P = [Sar9Met(O2)11]substance P > substance P-methyl ester = physalaemin > neurokinin A = neurokinin B >> [beta Ala8]neurokinin A (4-10). The novel NK1 antagonist CP-99,994 has a Ki of 0.4 nM at this NK1 site. 3. In order to characterize [125I]-neurokinin A binding to guinea-pig lung, the number of [125I]-neurokinin A specific binding sites was increased 3-4 fold by purification of the parenchymal membranes over discontinuous sucrose gradients. The rank order of affinity determined for NK1- and NK2-receptor agonists and antagonists in competition for these sites showed that the majority (80%) of [125I]-neurokinin A specific binding was also to the NK1 receptor. 4. Under conditions where the guinea-pig lung parenchymal NK1 receptor was fully occupied by a saturating concentration of either [Sar9Met(O2)11]substance P (1 microM) or CP-99,994 (2.7 microM), residual [125I]-neurokinin A specific binding was inhibited in a concentration-dependent manner by both [beta Ala8]neurokinin A and SR48968. This result shows that the NK2 receptor is also present in these preparations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7694756

  9. Strain-dependent CNS dissemination in guinea pigs after Mycobacterium tuberculosis aerosol challenge.

    PubMed

    Be, Nicholas A; Klinkenberg, Lee G; Bishai, William R; Karakousis, Petros C; Jain, Sanjay K

    2011-09-01

    Clinical reports suggest an association of distinct Mycobacterium tuberculosis strains with CNS disease. We therefore examined CNS dissemination by different laboratory strains (two M. tuberculosis H37Rv, one CDC1551) in a guinea pig aerosol infection model. Although all strains grew exponentially in lungs, with similar bacterial burdens at the time of extrapulmonary dissemination, M. tuberculosis CDC1551 disseminated to the CNS significantly more than the H37Rv strains. No CNS lesions were observed throughout the study, with only a modest cytokine response. These data suggest that M. tuberculosis may have virulence factors that promote CNS dissemination, distinct from those required for pulmonary TB.

  10. Carrageenan-induced ulceration of the large intestine in the guinea pig.

    PubMed

    Watt, J; Marcus, R

    1971-02-01

    A 5% aqueous solution of degraded carrageenan derived from the red seaweed Eucheuma spinosum was fed to guinea pigs in their drinking water over a period of 20-45 days. Occult blood in the faeces and multiple ulcers in the caecum, colon and rectum occurred in 100% of animals by the 30th day. The clinical and pathological features bear a close resemblance to human ulcerative colitis. The method provides a simple experimental model for the study of various aspects of the pathology of ulcerative lesions in the large intestine as well as the effects of therapeutic agents. PMID:5548564

  11. [The auditory pathway in guinea pigs. A [14C]2-deoxyglucose study (author's transl)].

    PubMed

    Strutz, J; Beck, C; Schmidt, C L

    1981-01-01

    The auditory pathway of guinea pigs was labeled with [14C]-deoxyglucose after mon- or binaural stimulation with farfield white noise in a sound-proof chamber. In the autoradiographs, all auditory nuclei were labeled. The highest metabolic effects were seen in the dorsal cochlear nucleus, the lateral superior olivary nucleus, and in the inferior colliculus. No selective labeling was observed in the auditory cortex. Monaural stimulation depressed the metabolic activity contralaterally in the ventral cochlear nucleus and ipsilaterally in the medial nucleus of the trapezoid body, the dorsomedial periolivary nucleus, and in the inferior colliculus. PMID:7213192

  12. Synaptic potentials recorded from neurones of the submucous plexus of guinea-pig small intestine.

    PubMed Central

    Hirst, G D; McKirdy, H C

    1975-01-01

    1. Intracellular recordings have been made from neurones lying in the submucous plexus of guinea-pig mid small intestine. 2. Most neurones in this plexus receive an extensive excitatory input which could be abolished by tubocurarine. 3. A proportion of neurones also received a single inhibitory input which was activated by transmural stimulation. 4. Some of the characteristics of the inhibitory potentials evoked by transmural stimulation are described. 5. The observations are discussed in relation to the concept of descending excitation (Hirst, Holman & McKirdy, 1975). Images a b c PMID:1177096

  13. Effects of acute ozone exposure on the electrophysiological properties of guinea pig trachea

    SciTech Connect

    Croxton, T.L.; Takahashi, Masahiko; Kokia, Ira

    1994-12-31

    Acute ozone (O{sub 3}) exposures produce an increase in the apparent permeability of the tracheal epithelium, but the mechanism of this response is poorly understood. Comparison of previous studies suggests that qualitative differences may exist between measurements made in vivo or in vitro. To test this possibility we used both in vitro and in vivo electrophysiological techniques to investigate the effects of O{sub 3} exposure on guinea pig tracheal epithelium. Male Hartley guinea pigs were exposed to either 1 or 2 ppm O{sub 3} or to filtered air for 3 h and were studied 0, 6, or 24 h after exposure. Air-exposed animals had in vitro mean tracheal potential (V{sub T}) -32.0 {+-} 1.5 mV, conductance (G{sub T}{sup L}) 2.18 {+-} 0.22 mS/cm, short-circuit current (I{sub SC}{sup L}) 62.6 {+-} 3.7 {mu}A/cm, and diameter (D) 2.44 {+-} 0.10 mm. In vitro properties after 1 ppm O{sub 3} exposure did not differ at any time point from control. Two parts per million O{sub 3} increased I{sub SC}{sup L}, but only at 6 h postexposure. The effect of O{sub 3} on I{sub SC}{sup L} was abolished by amiloride. There were no significant changes in V{sub T}, G{sub T}{sup L}, or D. In vivo tracheal potential under pentobarbital anesthesia was -19.7 {+-} 1.7 mV. At 6 h postexposure to 2 ppm O{sub 3}, but not at 0 or 24 h, in vivo V{sub I} was increased. Thus, acute exposure of guinea pigs to a high concentration of O{sub 3} caused a delayed increase in Na{sup +} absorption by the trachea with no change in conductance. This indicates that paracellular permeability of guinea pig tracheal epithelium was not substantially increased by acute O{sub 3} and suggests that enhanced macromolecular uptake in this species probably occurs transcellularly. 24 refs., 1 fig., 2 tabs.

  14. Production of arachidonic and linoleic acid metabolites by guinea pig tracheal epithelial cells

    SciTech Connect

    Oosthuizen, M.J.; Engels, F.; Van Esch, B.; Henricks, P.A.; Nijkamp, F.P. )

    1990-08-01

    Pulmonary epithelial cells may be responsible for regulating airway smooth muscle function, in part by release of fatty acid-derived mediators. Incubation of isolated guinea pig tracheal epithelial cells with radiolabeled arachidonic acid (AA) leads to the production of 5- and 15-hydroxyeicosatetraenoic acid (5- and 15-HETE) and smaller amounts of leukotriene (LT) B4 and C4 and 12-hydroxyheptadecatrienoic acid (HHT). Epithelial cells also are able to release linoleic acid (LA) metabolites. Incubation with radiolabeled linoleic acid leads to the formation of 9- and 13-hydroxyoctadecadienoic acid (9- and 13-HODE). The biological significance of these mediators produced by epithelial cells is discussed.

  15. Ultrastructural and Metabolic Determinants of Resistance to Azo-dye and Susceptibility to Nitrosamine Carcinogenesis of the Guinea-pig

    PubMed Central

    Bryant, G. M.; Sohal, R. S.; Argus, M. F.; Arcos, J. C.

    1977-01-01

    During diethylnitrosamine (DEN) administration, a distinctive difference was observed between rats and guinea-pigs in the sequence of ultrastructural changes in the hepatic endoplasmic reticulum (ER). In DEN-induced hepatic tumour cells in the guinea-pig there was extensive proliferation of the rough ER, while the smooth ER was quite sparse; in the premalignant liver the opposite was noted. This is in contrast to the rat, in which administration of either DEN or 3′-methyl-4-dimethylaminoazobenzene (3′-Me-DAB) brings about, in both premalignant and malignant hepatic tissue, proliferation of the smooth ER and sparsity of the rough ER. Yet, as in the rat, the number of ribosomes on the outer surface of the guinea-pig liver rough ER is greatly reduced and this is paralleled by a 49% decrease of the RNA/protein ratio as early as 4 weeks of nitrosamine administration. The decrease of RNA/protein ratio and ultrastructurally observed loss of ribosomes from the ER, following nitrosamine administration, correlate with a decrease of photometric response of microsomal suspensions to the sulphydryl probe, p-chloromercuribenzoate. While azo-dye-reductase activity is higher in untreated rats than in untreated guinea-pigs, feeding 3′-Me-DAB for 6 weeks brings about a 76% decrease in the rat, but no significant decrease in the guinea-pig, which is refractory to azo-dye carcinogenesis. Thus, the ability of the liver to inactivate the dye is greatly decreased in the rat, but not in the guinea-pig, as administration progresses toward the threshold dose for tumorigenesis. On the other hand, constitutive levels of nitrosamine dealkylase are identical in the 2 species and remain essentially unchanged following administration of DEN for 10 weeks. Inasmuch as nitrosamine dealkylation represents activating metabolism, this provides a rationale for the comparable susceptibility of the rat and guinea-pig to DEN carcinogenesis. Of the 2 enzymes in the 2 species, it is only azo

  16. Antagonism of acetylcholine action in guinea-pig tracheal smooth muscle and epithelium by pirenzepine, 4-DAMP and atropine.

    PubMed

    Orer, H S; Guc, M O; Rezaki, Y E; Ilhan, M; Kayaalp, S O

    1990-01-01

    Acetylcholine-induced guinea-pig tracheal smooth muscle contraction and epithelium-derived relaxant factor release were evaluated using guinea-pig open tracheal rings and rat anococcygeus muscle bioassay to get insight into the participation of muscarinic receptor subtypes in these responses. There was a significant difference between the two pA2 values obtained in contraction and relaxation experiments for pirenzepine, but no difference was found either for atropine or for 4-DAMP. This difference seems to be due to the participation of M1-receptors in smooth muscle contraction.

  17. Identification of beta 2-adrenoceptors on guinea pig alveolar macrophages using (-)-3-( sup 125 I)iodocyanopindolol

    SciTech Connect

    Leurs, R.; Beusenberg, F.D.; Bast, A.; Van Amsterdam, J.G.; Timmerman, H. )

    1990-08-01

    The beta-adrenoceptor antagonist (-)-3-({sup 125}I)iodocyanopindolol (({sup 125}I)ICYP) binds with high affinity and in saturable way to membranes of guinea pig alveolar macrophages. The equilibrium dissociation constant for ({sup 125}I)ICYP is 24.3 +/- 1.2 pM, and the number of binding sites is 166.3 +/- 13.7 fmol/mg protein (N = 4, +/- SEM). Displacement studies with selective antagonists showed that ({sup 125}I)ICYP labels beta 2-adrenoceptors on guinea pig alveolar macrophages.

  18. An Ex vivo culture model for placental cytomegalovirus infection using slices of Guinea pig placental tissue.

    PubMed

    Yamada, Souichi; Katano, Harutaka; Sato, Yuko; Fukuchi, Saki; Hashimoto, Kaede; Inoue, Naoki

    2016-01-01

    Congenital infection with human cytomegalovirus (CMV) through the placenta is one of the major causes of birth and developmental abnormalities. Guinea pig CMV (GPCMV) causes in utero infection, which makes its animal models useful for studies on congenital diseases. Here, we established an ex vivo culture method for tissue slices prepared from guinea pig placentas and demonstrated that viral spread in the model resembles those in the placenta of GPCMV-infected animals and that the infection is independent of the pentameric glycoprotein complex for endothelial/epithelial cell tropism. Thus, this model affords a useful tool for pathobiological studies on CMV placental infection.

  19. Guinea pig-adapted foot-and-mouth disease virus with altered receptor recognition can productively infect a natural host.

    PubMed

    Núñez, José I; Molina, Nicolas; Baranowski, Eric; Domingo, Esteban; Clark, Stuart; Burman, Alison; Berryman, Stephen; Jackson, Terry; Sobrino, Francisco

    2007-08-01

    We report that adaptation to infect the guinea pig did not modify the capacity of foot-and-mouth disease virus (FMDV) to kill suckling mice and to cause an acute and transmissible disease in the pig, an important natural host for this pathogen. Adaptive amino acid replacements (I(248)-->T in 2C, Q(44)-->R in 3A, and L(147)-->P in VP1), selected upon serial passages of a type C FMDV isolated from swine (biological clone C-S8c1) in the guinea pig, were maintained after virus multiplication in swine and suckling mice. However, the adaptive replacement L(147)-->P, next to the integrin-binding RGD motif at the GH loop in VP1, abolished growth of the virus in different established cell lines and modified its antigenicity. In contrast, primary bovine thyroid cell cultures could be productively infected by viruses with replacement L(147)-->P, and this infection was inhibited by antibodies to alphavbeta6 and by an FMDV-derived RGD-containing peptide, suggesting that integrin alphavbeta6 may be used as a receptor for these mutants in the animal (porcine, guinea pig, and suckling mice) host. Substitution T(248)-->N in 2C was not detectable in C-S8c1 but was present in a low proportion of the guinea pig-adapted virus. This substitution became rapidly dominant in the viral population after the reintroduction of the guinea pig-adapted virus into pigs. These observations illustrate how the appearance of minority variant viruses in an unnatural host can result in the dominance of these viruses on reinfection of the original host species. PMID:17522230

  20. l-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs

    PubMed Central

    Frikke-Schmidt, Henriette; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2015-01-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)—commonly found in vitamin C containing food products prone to oxidation—was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25 mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs—as in humans—is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis. PMID:26609560

  1. Efficacy comparison of scopolamine (SCP) and diazepam (DZ) against soman-induced lethality in guinea pigs

    SciTech Connect

    Harris, L.W.; Gennings, C.; Carter, W.H.; Anderson, D.R.; Lennox, W.J.

    1994-12-31

    Diazepam (DZ) and scopolamine (SCP) are known to be beneficial when each is used in combination with atropine (AT) + oxime therapy against intoxication by soman, but the efficacy of each might be expected to vary with the dosage of AT. Thus, the therapeutic efficacy of SCP (5 doses; 0 - 0.86 mg/kg) versus DZ (5 doses; 0 - 5 mg/kg), when used in conjunction with AT (3 doses; 0.5 - S mg/kg) + 2-PAM (25 mg/kg) therapy, was tested in groups of pyridostigmine pretreated guinea pigs exposed to 1.6, 2.0, 2.5 or 3.2 LD5Os of soman. Response surface methodology was employed to describe the relationship between lethality and the AT/DZ or AT/SCP dosages. Results show that within the indicated dose ranges used, the efficacy of SCP is not dependent on the presence of AT, whereas AT is needed for DZ to maintain the lowest probability of death. These findings suggest that in guinea pigs SCP could supplement AT or replace DZ as therapy against nerve agent intoxication.

  2. Efficacy comparison of scopolamine and diazepam against soman-induced debilitation in guinea pigs

    SciTech Connect

    Anderson, D.R.; Gennings, C.; Carter, W.H.; Harris, L.W.; Lennox, W.J.

    1994-12-31

    The efficacy of diazepam (DZ) and scopolamine (SCP), in combination with atropine (ATR) + oxime therapy, against soman-induced seizure/convulsive activity and associated brain damage has been demonstrated, but the efficacy of each against the incapacitating effects of soman has not been addressed. Thus, the therapeutic efficacies of SCP (5 doses; 0-0.86 mg/kg) and DZ (5 doses; 0-5 mg/kg), when each was used in conjunction with ATR (3 doses; 0.5-8 mg/kg) + 2-PAM (25 mg/kg) therapy, were compared in groups of pyridostigmine pretreated guinea pigs exposed to 1.6, 2.0, 2.5, or 3.2 LD5Os of soman. Response surface methodology was employed to describe the relationship between soman-induced incapacitation and the ATR/DZ or ATRISCP dosages. Incapacitation was measured by toxicity scores assigned by three graders to test animals at 60 min postsoman. Results show that as the dosage of SCP increased, the mean toxicity scores decreased. Also, within the indicated dose ranges used, the efficacy of SCP was not dependent on the presence of ATR. In contrast, ATR alone was found to be more effective than when combined with DZ at any dose, and indicates that DZ might be temporarily contributing to soman-induced incapacitation. These findings suggest that in guinea pigs, SCP could replace ATR or DZ, or both, as therapy against soman-induced incapacitation.

  3. Persistent structural adaptation in the lungs of guinea pigs raised at high altitude.

    PubMed

    Ravikumar, Priya; Bellotto, Dennis J; Hsia, Connie C W

    2015-03-01

    Laboratory guinea pigs raised at high altitude (HA, 3800 m) for up to 6 mo exhibit enhanced alveolar growth and remodeling (Hsia et al., 2005. Resp. Physiol. Neurobiol. 147, 105-115). To determine whether initial HA-induced structural enhancement persists following return to intermediate altitude (IA), we raised weanling guinea pigs at (a) HA for 11-12 mo, (b) IA (1200 m) for 11-12 mo, and (c) HA for 4 mo followed by IA for 7-8 mo (HA-to-IA). Morphometric analysis was performed under light and electron microscopy. Body weight and lung volume were similar among groups. Prolonged HA residence increased alveolar epithelium and interstitium volumes while reducing alveolar-capillary blood volume. The HA-induced gains in type-1 epithelium volume and alveolar surface area were no longer present following return to IA whereas volume increases in type-2 epithelium and interstitium and the reduction in alveolar duct volume persisted. Results demonstrate persistent augmentation of some but not all aspects of lung structure throughout prolonged HA residence, with partial reversibility following re-acclimatization to IA.

  4. Representation of the purr call in the guinea pig primary auditory cortex.

    PubMed

    Wallace, Mark N; Shackleton, Trevor M; Anderson, Lucy A; Palmer, Alan R

    2005-06-01

    Guinea pigs produce the low-frequency purr or rumble call as an alerting signal. A digitised example of the call was presented to anaesthetised guinea pigs via a closed sound system while recording from the primary auditory cortex. The exemplar used in this study had 9 regular phrases each spaced with their centres about 80 ms apart. Low-frequency (1.1 kHz) units responded best to the call but within this population there were four separate groups: (1) cells that responded vigorously to many or all of the 9 phrases; (2) cells that gave an onset response; (3) cells that only responded to a click embedded in the call; (4) cells that did not respond. Particular response types were often grouped together. Thus when orthogonal electrode tracks were used most units gave a similar response. There was no correlation between the type of response and the cortical depth. A similar range of response types was also found in the thalamus and there was no evidence of a distinct response in the cortex that was due to intracortical processing. Cells in the cortex were able to represent the temporal structure of the purr with the same fidelity as cells in the thalamus.

  5. Antihyperalgesic activity of nucleoside transport inhibitors in models of inflammatory pain in guinea pigs

    PubMed Central

    Maes, Sabine S; Pype, Stefan; Hoffmann, Vincent LH; Biermans, Maria; Meert, Theo F

    2012-01-01

    Background and methods The role of the endogenous purine nucleoside, adenosine, in nociception is well established. Inhibition of the equilibrative nucleoside transporter (ENT1) prevents adenosine uptake into cells, and could therefore enhance the antinociceptive properties of adenosine. The effects of ENT1 inhibition were studied in two animal models of inflammatory pain. Analgesic activity was assessed in a complete Freund’s adjuvant (CFA)-induced and carrageenan-induced mechanical and thermal hyperalgesia model in the guinea pig. Results Draflazine, dipyridamole, dilazep, lidoflazine, soluflazine, and KF24345 showed efficacy in the CFA thermal hyperalgesia model. Draflazine, the most potent compound in this test, was further characterized in the CFA model of mechanical hyperalgesia and the carrageenan inflammation model of thermal and mechanical hyperalgesia, where it completely reversed the hypersensitivity. The antihyperalgesic effects of draflazine (10 mg/kg, administered subcutaneously) were attenuated by the A1 receptor antagonist, cyclopentyltheophylline (5–40 mg/kg, administered intraperitoneally), by the nonselective adenosine antagonist, caffeine (10–40 mg/kg intraperitoneally), and by the A2 antagonist, DMPX (10 mg/kg administered intraperitoneally). Conclusion ENT1 inhibition is an effective way of reversing mechanical and thermal inflammatory hyperalgesia in the guinea pig, and these effects are mediated by enhancement of endogenous adenosine levels. Both A1 and A2 adenosine receptor subtypes are likely to be involved. PMID:23091396

  6. Photoprotective role of epidermal melanin granules against ultraviolet damage and DNA repair in guinea pig skin

    SciTech Connect

    Ishikawa, T.; Kodama, K.; Matsumoto, J.; Takayama, S.

    1984-11-01

    We previously developed a quantitative autoradiographic technique with special forceps for measuring unscheduled DNA synthesis (UDS) in mouse skin after treatment with ultraviolet light in vivo. By this method, we investigated the relationship between the protective role of melanin and UV-induced DNA repair in black-and-white guinea pigs. Flat areas containing a sharp border between pigmented and unpigmented skin were selected. The skin of the selected areas was shaved and irradiated with short-wave UV (254 nm) or UV-AB (270 to 440 nm, emission peak at 312 nm) at various doses. Immediately after irradiation, the skin was clamped off with forceps, and an isotonic aqueous solution of (methyl-/sup 3/H)thymidine was injected s.c. into the clamped off portion. UDS was clearly demonstrated as silver grains in this portion of the skin after irradiation with 254 nm UV or UV-AB. Errors due to individual differences were avoided by comparing the intensities of UDS in basal cells from pigmented skin and unpigmented skin of the same animals. Unexpectedly, in groups of animals treated with 254 nm UV or UV-AB, no difference in UDS in pigmented and unpigmented skin was seen at any UV dose. These results suggested that epidermal melanin granules do not significantly protect DNA of basal cells against 254 nm UV or UV-AB irradiation. Results of a study on the effect of the wavelength of irradiation on the UDS response of albino guinea pigs are also reported.

  7. The temporal representation of speech in a nonlinear model of the guinea pig cochlea

    NASA Astrophysics Data System (ADS)

    Holmes, Stephen D.; Sumner, Christian J.; O'Mard, Lowel P.; Meddis, Ray

    2004-12-01

    The temporal representation of speechlike stimuli in the auditory-nerve output of a guinea pig cochlea model is described. The model consists of a bank of dual resonance nonlinear filters that simulate the vibratory response of the basilar membrane followed by a model of the inner hair cell/auditory nerve complex. The model is evaluated by comparing its output with published physiological auditory nerve data in response to single and double vowels. The evaluation includes analyses of individual fibers, as well as ensemble responses over a wide range of best frequencies. In all cases the model response closely follows the patterns in the physiological data, particularly the tendency for the temporal firing pattern of each fiber to represent the frequency of a nearby formant of the speech sound. In the model this behavior is largely a consequence of filter shapes; nonlinear filtering has only a small contribution at low frequencies. The guinea pig cochlear model produces a useful simulation of the measured physiological response to simple speech sounds and is therefore suitable for use in more advanced applications including attempts to generalize these principles to the response of human auditory system, both normal and impaired. .

  8. Pharmacokinetics of niacinamide in blood and skin of hairless guinea pigs

    SciTech Connect

    Bongiovannieier, R.; Koplovitz, I.; Shulz, S.; Lieb, J.; Railer, R.

    1993-05-13

    Niacinamide (NA) has been reported to be effective in reducing the development of microblisters caused by sulfur mustard (HD) vapor exposure in the Hairless guinea pig when given as a single bolus pretreatment 30 min prior to HD vapor exposure (Yourick et al.). The purpose of these experiments was to establish the pharmacokinetics of NA in the hairless guinea pig to optimize the evaluation of NA against HD cutaneous injury. A high performance liquid chromatography (HPLC) method was developed for the quantitation of NA in blood and skin. The method was linear (corr coeff r = 0.998) and sensitive with a working range from 50 microns/ml to 2000 microns/ml. The NA Tl/2 was measured after a bolus injection of 750 and 375 mg/kg via IP and IV routes, respectively. The Tl/2 was 2.8 + or - 0.3 hr for both routes. Drug concentrations in blood, during multiple dosing (5 IP) of a fixed dose (375 mg/kg, i.p.) given every 2.8 hr, were within 15% of the theoretical values calculated using a computer model (Principle of Superposition). NA serum levels ranged from 325 microns/mL to 1404 microns/mL (n = 12). The corresponding skin levels were within 93% of the blood levels. The elimination of NA from the skin paralleled its elimination from the blood. The results of these studies will aid in the future evaluation of NA as a pretreatment/treatment for HD injury.

  9. Guinea pigs: a suitable animal model to study lipoprotein metabolism, atherosclerosis and inflammation.

    PubMed

    Fernandez, Maria Luz; Volek, Jeff S

    2006-03-27

    Numerous animal models have been used to study diet effects on cholesterol and lipoprotein metabolism. However, most of those models differ from humans in the plasma distribution of cholesterol and in the processing of lipoproteins in the plasma compartment. Although transgenic or knock-out mice have been used to study a specific pathway involved in cholesterol metabolism, these data are of limited use because other metabolic pathways and responses to interventions may differ from the human condition. Carbohydrate restricted diets have been shown to reduce plasma triglycerides, increase HDL cholesterol and promote the formation of larger, less atherogenic LDL. However, the mechanisms behind these responses and the relation to atherosclerotic events in the aorta have not been explored in detail due to the lack of an appropriate animal model. Guinea pigs carry the majority of the cholesterol in LDL and possess cholesterol ester transfer protein and lipoprotein lipase activities, which results in reverse cholesterol transport and delipidation cascades equivalent to the human situation. Further, carbohydrate restriction has been shown to alter the distribution of LDL subfractions, to decrease cholesterol accumulation in aortas and to decrease aortic cytokine expression. It is the purpose of this review to discuss the use of guinea pigs as useful models to evaluate diet effects on lipoprotein metabolism, atherosclerosis and inflammation with an emphasis on carbohydrate restricted diets.

  10. Radioprotective Effect of Aminothiol PrC-210 on Irradiated Inner Ear of Guinea Pig.

    PubMed

    Giese, Arnaud P J; Guarnaschelli, Jess G; Ward, Jonette A; Choo, Daniel I; Riazuddin, Saima; Ahmed, Zubair M

    2015-01-01

    Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino)-2-((methylamino)methyl)propane-1-thiol) on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiation (3000 cGy) to each ear. Auditory Brainstem Responses (ABRs) were recorded one week and two weeks after the radiation and compared with the sham animal group. ABR thresholds of guinea pigs that received an intra-peritoneal dose of PrC-210 were significantly better compared to the non-treated, control animals at one week post-radiation. Morphologic analysis of the inner ear revealed significant inflammation and degeneration of the spiral ganglion in the irradiated animals not treated with PrC-210. In contrast, when treated with PrC-210 the radiation effect and injury to the spiral ganglion was significantly alleviated. PrC-210 had no apparent cytotoxic effect in vivo and did not affect the morphology or count of cochlear hair cells. These findings suggest that aminothiol PrC-210 attenuated radiation-induced cochlea damage for at least one week and protected hearing. PMID:26599238

  11. Effect of Binghuang ear drop treatment on otitis externa in guinea pigs.

    PubMed

    Zhai, Suo-qiang; Yu, Ning; Guo, Wei-Wei; Zhang, Yue

    2014-12-01

    To investigate the pharmacodynamic effects of Binghuang ear drop on acute suppurative otitis externa in guinea pig model. Thirty guinea pigs were randomly divided into three groups, with ten animals in each group. Group A animals had normal ear canal and Binghuang ear drops (two drops, B.I.D) were applied in both ears for 7 days; Group B animals had induced otitis externa and received identical prescription as group A; Group C had normal ear canal and were treated with normal saline (two drops, B.I.D) for 7 days. After the treatments, the external morphology of ear canals was observed and the paraffin sections of external auditory canal were prepared and examined under the microscope. The inflammatory manifestation and cell infiltration into the skin of group B was significantly attenuated after the Binghuang ear drops treatment. In contrast, no allergy or side effects were produced by Binghuang ear drops application in the animals with normal ear canals. Binghuang ear drops could be used to treat acute otitis externa by eliciting anti-bacterial effects. PMID:25269771

  12. Integrated Omic Analysis of a Guinea Pig Model of Heart Failure and Sudden Cardiac Death.

    PubMed

    Foster, D Brian; Liu, Ting; Kammers, Kai; O'Meally, Robert; Yang, Ni; Papanicolaou, Kyriakos N; Talbot, C Conover; Cole, Robert N; O'Rourke, Brian

    2016-09-01

    Here, we examine key regulatory pathways underlying the transition from compensated hypertrophy (HYP) to decompensated heart failure (HF) and sudden cardiac death (SCD) in a guinea pig pressure-overload model by integrated multiome analysis. Relative protein abundances from sham-operated HYP and HF hearts were assessed by iTRAQ LC-MS/MS. Metabolites were quantified by LC-MS/MS or GC-MS. Transcriptome profiles were obtained using mRNA microarrays. The guinea pig HF proteome exhibited classic biosignatures of cardiac HYP, left ventricular dysfunction, fibrosis, inflammation, and extravasation. Fatty acid metabolism, mitochondrial transcription/translation factors, antioxidant enzymes, and other mitochondrial procsses, were downregulated in HF but not HYP. Proteins upregulated in HF implicate extracellular matrix remodeling, cytoskeletal remodeling, and acute phase inflammation markers. Among metabolites, acylcarnitines were downregulated in HYP and fatty acids accumulated in HF. The correlation of transcript and protein changes in HF was weak (R(2) = 0.23), suggesting post-transcriptional gene regulation in HF. Proteome/metabolome integration indicated metabolic bottlenecks in fatty acyl-CoA processing by carnitine palmitoyl transferase (CPT1B) as well as TCA cycle inhibition. On the basis of these findings, we present a model of cardiac decompensation involving impaired nuclear integration of Ca(2+) and cyclic nucleotide signals that are coupled to mitochondrial metabolic and antioxidant defects through the CREB/PGC1α transcriptional axis.

  13. Spontaneous tone in different types of longitudinal muscle preparations of guinea pig ileum.

    PubMed

    Suzuki, N; Shibayama, T; Mambo, T; Gomi, Y

    1995-09-01

    Spontaneous tone of longitudinal muscle in guinea pig ileum was investigated in three types of preparations, intact segment preparation, segment preparation deprived of the mucosal layer and longitudinal strip preparation. Tone was defined as the sustained contraction that was lost by 10(-7) M atropine in the isotonically recorded manner. The magnitudes of tone were constant for at least 3 hr in the two types of segment preparations. Contractions in response to 10(-6) M acetylcholine, which were induced 9 times with an interval of 20 min between each induction, were almost identical throughout the period. In the longitudinal strip preparation, on the other hand, the tone gradually decayed and was eventually lost, while the amplitudes of acetylcholine-induced contractions were reciprocally increased. The tone in the intact segment preparation was reduced to 19% of the control by tetrodotoxin (3 x 10(-7) M), to 51% by indomethacin (3 x 10(-6) M) and to 26% by N6-cyclopentyladenosine (10(-7) M), but was not affected by AA-861 (3 x 10(-6) M) or CP-96,345 (3 x 10(-7) M). In the three types of preparations, the dose-response curves for acetylcholine were alike with similar EC50s. These results suggest that the tone of longitudinal muscle was mainly induced due to neural activity in the myenteric plexus of guinea pig ileum and that sensitivity to acetylcholine was not affected by the neural activity.

  14. The effects of malnutrition on variables of host defense in the guinea pig.

    PubMed

    Wunder, J A; Stinnett, J D; Alexander, J W

    1978-10-01

    Studies were conducted in young guinea pigs to determine the effects of malnutrition on selected variables of host resistance. Malnutrition was produced differently in two experiments. In the first the quantity of a standard, normal diet was reduced progressively so that test groups were fed 25% less each week over a 4 week period. Control groups were fed ad libitum. In the subsequent experiment, animals were fed defined guinea pig diets containing 5%, 30%, and 60% casein, respectively, which were similar in caloric content, vitamins, and minerals. Measurements of phagocytic bactericidal activity, serum opsonization, serum IgG and C3 levels, and mitogenic response of lymphocytes were made at weekly intervals. Results obtained from both experiments were comparable. There was a significant decline in phagocyte function by the third week in malnourished animals while the numbers of phagocytes per milliliter of peritoneal washings were similar to controls at all time periods. A depression of serum opsonization was observed when animals became moribund even though serum IgG levels remained unchanged. Serum C3 levels in malnourished animals were significantly lower than controls. Mitogenic response of lymphocytes to phytohemagglutinin was 85% lower in the 5% casein group after the third week. These results indicated that a marasmus-like condition and protein malnutrition depress critical functions of resistance.

  15. Low temperature scanning electron microscopy of dog and guinea-pig hyaline articular cartilage.

    PubMed Central

    Gardner, D L; O'Connor, P; Oates, K

    1981-01-01

    Fifty seven blocks of cartilage excised from the femoral condyles of 20 beagle dogs, and whole lower ends of 5 guinea-pig femora, were examined at -195 degrees (78 K), by scanning electron microscopy. The unfixed tissue, taken into slushy nitrogen at -210 degrees (63 K), was not exposed to atmospheric air after quenching and remained fully hydrated throughout long periods of observation. Images susceptible to analysis were obtained from washed and from unwashed cartilage surfaces. Preliminary coating with gold or with aluminium, known to be possible without exposing cold cartilage surfaces to changes in temperature likely to cause water loss by sublimation, was valuable in minimising charging and in facilitating the recording of electron images at higher magnifications. Although examination was possible without coating, the resultant images were of low resolution. Microscopy revealed a pattern of secondary surface irregularities of tertiary elevations closely resembling those seen by the conventional scanning electron microscopy of fixed, dehydrated hyaline cartilage. However, the pattern of tertiary surface structures was predominantly that of elevations, not of hollows. Quaternary surface ridges were common on the surfaces of excised dog cartilage blocks and were not seen on the surfaces of guinea-pig cartilage which remained on the femoral condyles. 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 Fig. 13 Fig. 14 PMID:7024225

  16. First spike latency code for interaural phase difference discrimination in the guinea pig inferior colliculus.

    PubMed

    Zohar, Oran; Shackleton, Trevor M; Nelken, Israel; Palmer, Alan R; Shamir, Maoz

    2011-06-22

    First spike latency has been suggested as a source of the information required for fast discrimination tasks. However, the accuracy of such a mechanism has not been analyzed rigorously. Here, we investigate the utility of first spike latency for encoding information about the location of a sound source, based on the responses of inferior colliculus (IC) neurons in the guinea pig to interaural phase differences (IPDs). First spike latencies of many cells in the guinea pig IC show unimodal tuning to stimulus IPD. We investigated the discrimination accuracy of a simple latency code that estimates stimulus IPD from the preferred IPD of the single cell that fired first. Surprisingly, despite being based on only a single spike, the accuracy of the latency code is comparable to that of a conventional rate code computed over the entire response. We show that spontaneous firing limits the capacity of the latency code to accumulate information from large neural populations. This detrimental effect can be overcome by generalizing the latency code to estimate the stimulus IPD from the preferred IPDs of the population of cells that fired the first n spikes. In addition, we show that a good estimate of the neural response time to the stimulus, which can be obtained from the responses of the cells whose response latency is invariant to stimulus identity, limits the detrimental effect of spontaneous firing. Thus, a latency code may provide great improvement in response speed at a small cost to the accuracy of the decision. PMID:21697370

  17. Greenwood frequency-position relationship in the primary auditory cortex in guinea pigs.

    PubMed

    Nishimura, Masataka; Song, Wen-Jie

    2014-04-01

    Although orderly representation of sound frequency over space is a hallmark feature of the primary auditory cortex (A1), the quantitative relationship between sound frequency and cortical position is unclear. We examined this relationship in the guinea pig A1 by presenting a series of stimulus tones with a wide frequency range, and recording the evoked cortical responses using an optical imaging technique with high spatial resolution. We identified the cortical positions of three best-frequency indices for each tone: the onset response position, the peak amplitude position, and the maximum rise rate position of the response. We found a nonlinear log frequency-position relationship for each of the three indices, and the frequency-position relationship was always well described by a Greenwood equation, with correlation coefficients greater than 0.98. The cortical magnification factor, measured in octave/mm, was found to be a function of frequency, i.e. not a constant. Our results are novel in that they demonstrate a quantitative relationship between sound frequency and cortical position in the guinea pig A1, as described by the Greenwood equation. PMID:24342224

  18. Primary neural degeneration in the Guinea pig cochlea after reversible noise-induced threshold shift.

    PubMed

    Lin, Harrison W; Furman, Adam C; Kujawa, Sharon G; Liberman, M Charles

    2011-10-01

    Recent work in mouse showed that acoustic overexposure can produce a rapid and irreversible loss of cochlear nerve peripheral terminals on inner hair cells (IHCs) and a slow degeneration of spiral ganglion cells, despite full recovery of cochlear thresholds and no loss of inner or outer hair cells (Kujawa and Liberman, J Neurosci 29:14077-14085, 2009). This contrasts with earlier ultrastructural work in guinea pig suggesting that acute noise-induced neural degeneration is followed by full regeneration of cochlear nerve terminals in the IHC area (Puel et al., Neuroreport 9:2109-2114, 1998; Pujol and Puel, Ann N Y Acad Sci 884:249-254, 1999). Here, we show that the same patterns of primary neural degeneration reported for mouse are also seen in the noise-exposed guinea pig, when IHC synapses and cochlear nerve terminals are counted 1 week post-exposure in confocal images from immunostained whole mounts and that the same slow degeneration of spiral ganglion cells occurs despite no loss of IHCs and apparent recovery of cochlear thresholds. The data cast doubt on prior claims that there is significant neural regeneration and synaptogenesis in the adult cochlea and suggest that denervation of the inner hair cell is an important sequela of "reversible" noise-induced hearing loss, which likely applies to the human ear as well. PMID:21688060

  19. Antitussive effect of naringin on experimentally induced cough in Guinea pigs.

    PubMed

    Gao, Sen; Li, Peibo; Yang, Hongliang; Fang, Siqi; Su, Weiwei

    2011-01-01

    The mechanism of action of naringin has been investigated in different models of experimentally induced cough in guinea pigs. In contrast to codeine phosphate (6 mg/kg, intravenous administration [i. v.]), naringin (15, 30, and 60 mg/kg, i. v.) had no central antitussive effect on cough elicited by electrical stimulation of the superior laryngeal nerve. Naringin (0.5, 1.0, and 2.0 µmol) could not prevent the cough reflex induced by stimulation of the trachea after intracerebroventricular injection (i. c. v.), while codeine phosphate (0.5 µmol) was highly effective. Further characterizing the peripheral mechanism of naringin, we found that its effect (50 mg/kg, i. v.) was not affected by the depletion of sensory neuropeptides, whereas levodropropizine (10 mg/kg, i. v.) lost its capacity to prevent cough in the capsaicin-desensitized guinea pig. Furthermore, pretreatment with glibenclamide (10 mg/kg, intraperitoneal [i. p.]) significantly reduced the antitussive effect of pinacidil (5 mg/kg, subcutaneous [s. c.]), but could not antagonize the antitussive effect of naringin (30 mg/kg, s. c.). Our present results suggest that naringin is not a central antitussive drug. And naringin does not exert its peripheral antitussive effect through either the sensory neuropeptides system or the modulation of ATP-sensitive K (+) channels.

  20. Effects of the antitussive drug cloperastine on ventricular repolarization in halothane-anesthetized guinea pigs.

    PubMed

    Takahara, Akira; Fujiwara, Kaori; Ohtsuki, Atsushi; Oka, Takayuki; Namekata, Iyuki; Tanaka, Hikaru

    2012-01-01

    Cloperastine is an antitussive drug, which can be received as an over-the-counter cold medicine. The chemical structure of cloperastine is quite similar to that of the antihistamine drug diphenhydramine, which is reported to inhibit hERG K⁺ channels and clinically induce long QT syndrome after overdose. To analyze its proarrhythmic potential, we compared effects of cloperastine and diphenhydramine on the hERG K⁺ channels expressed in HEK293 cells. We further assessed their effects on the halothane-anesthetized guinea-pig heart under the monitoring of monophasic action potential (MAP) of the ventricle. Cloperastine inhibited the hERG K⁺ currents in a concentration-dependent manner with an IC₅₀ value of 0.027 μM, whose potency was 100 times greater than that of diphenhydramine (IC₅₀; 2.7 μM). In the anesthetized guinea pigs, cloperastine at a therapeutic dose of 1 mg/kg prolonged the QT interval and MAP duration without affecting PR interval or QRS width. Diphenhydramine at a therapeutic dose of 10 mg/kg prolonged the QT interval and MAP duration together with increase in PR interval and QRS width. The present results suggest that cloperastine may be categorized as a QT-prolonging drug that possibly induces arrhythmia at overdoses like diphenhydramine does.

  1. Regulation of (/sup 3/H)GABA release from strips of guinea pig urinary bladder

    SciTech Connect

    Shirakawa, J.; Taniyama, K.; Iwai, S.; Tanaka, C.

    1988-12-01

    The presence of receptors that regulate the release of gamma-aminobutyric acid (GABA) was studied in strips of the guinea pig urinary bladder. GABA (10(-8)-10(-5) M) and muscimol (10(-8)-10(-5) M), but not baclofen (10(-5) M), reduced the Ca2+-dependent, tetrodotoxin-resistant release of (/sup 3/H)GABA evoked by high K+ from the urinary bladder strips preloaded with (/sup 3/H)GABA. The inhibitory effect of muscimol was antagonized by bicuculline and potentiated by diazepam, clonazepam, and pentobarbital sodium. The potentiating effect of clonazepam was antagonized by Ro 15-1788. Acetylcholine (ACh) inhibited the high K+-evoked release of (/sup 3/H)GABA. The inhibitory effect of ACh was antagonized by atropine sulfate and pirenzepine but not by hexamethonium. Norepinephrine (NE) inhibited the evoked release of (/sup 3/H)GABA. The inhibitory effect of NE was mimicked by clonidine, but not by phenylephrine, and was antagonized by yohimbine but not by prazosin. These results provide evidence that the release of GABA from strips of guinea pig urinary bladder is regulated via the bicuculline-sensitive GABAA receptor, M1-muscarinic, and alpha 2-adrenergic receptors.

  2. Contractile activity of lymphatic vessels is altered in the TNBS model of guinea pig ileitis.

    PubMed

    Wu, Theresa F; Carati, Colin J; Macnaughton, Wallace K; von der Weid, Pierre-Yves

    2006-10-01

    The ability of the lymphatic system to actively remove fluid from the interstitium is critical to the resolution of edema. The response of the lymphatics to inflammatory situations is poorly studied, so we examined mesenteric lymphatic contractile activity in the 2,4,6-trinitrobenzenesulfonic acid (TNBS) model of guinea pig ileitis, a well-accepted animal model of intestinal inflammation, by videomicroscopy in vivo and in vitro 1, 3, and 6 days after induction of ileitis. Lymphatic function (diameter, constriction frequency, amplitude of constrictions, and calculated stroke volume and lymph flow rate) of isolated vessels from TNBS-treated guinea pigs were impaired compared with sham-treated controls. The dysfunction was well correlated with the degree of inflammation, with differences reaching significance (P < 0.05) at the highest inflammation-induced damage observed at day 3. In vivo, significantly fewer lymphatics exhibited spontaneous constrictions in TNBS-treated than sham-treated animals. Cyclooxygenase (COX) metabolites were suggested to be involved in this lymphatic dysfunction, since application of nonselective COX inhibitor (10 microM indomethacin) or a combination of COX-1 and COX-2 inhibitors (1 microM SC-560 and 10 microM celecoxib) markedly increased constriction frequency or induced them in lymphatics from TNBS-treated animals in vivo and in vitro. The present results demonstrate that lymphatic contractile function is altered in TNBS-induced ileitis and suggest a role for prostanoids in the lymphatic dysfunction.