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At least 19 recordsLinked to original sources
PubMed1976

Comparison of guinea pig cytomegalovirus and guinea pig herpes-like virus: growth characteristics and antigentic relationship.

The growth characteristics of guinea pig cytomegalovirus (GPCMV) and guinea pig herpes-like virus (GPHLV) in cell cultures were compared. Guinea pig fibroblast cells were highly susceptible to infection with both viruses, whereas guinea pig kidney cells were sensitive only to GPHLV. No cytopathic effect was observed in the latter cell system after infection with GPCMV,nor was there an increase in virus titer, although the cirus persisted in the kidney cells for 2 to 3 weeks postinfection. Electron microscope studies showed nonvirion tubular structures in GPCMV -infected fibroblast cells, but not in GPHLV- infected cells. Large packages of enveloped nuclear virus particles were commonly seen in GPHLV -infected cells, especially kidney epithelial cells, but none were found in the GPCMV -infected fibroblasts. Complete enveloped extracellular virus particles were present in both virus-cell systems. Both viruses showed narrow host spectra and replicated well only in guinea pig cells although GPHLV multiplied to some degree in rabbit cells. No antigenic relationship could be demonstrated between the two viruses using antisera specific for each virus that was produced in rabbits and guinea pigs. Rabbits produced high neutralizing antibody titers to GPHLV, whereas guinea pigs were the animals of choice for GPCMV antiserum production.

Animals↗
PubMed1975

Characterization of murine sarcoma virus transformation of guinea pig cells and activation of an RNA tumor-like virus from nonproducer guinea pig cells.

Guinea pig embryo (GEP) cells were transformed in vitro by the Kirsten strain of mouse sarcoma virus (Ki-MSV). The transformed cells were found to release infectious virus continuously and produced high titers of group-specific (gs) complement-fixing (CF) antigen characteristics of the murine sarcoma-leukemia virus complex. Foci of transformed cells were similar in appearance to those obtained with Ki-MSV in mouse and rat cells. The transformed cells produced RNA dependent DNA polymerase and type C virus particles with a density of approximately 1.15 g/ml in sucrose gradients by 3H-uridine labeling. The transformed cells produced tumors when transplanted into newborn guinea pigs. A number of focus-derived clonal lines from Ki-MSV transformed cells were isolated and characterized. All the focus-derived lines were found to be either producers or nonproducers (NP). The NP guinea pig cells produced neither infectious virus nor viral antigens of the murine sarcoma-leukemia virus complex although they were morphologically indistinguishable from virus-releasing MSV transformed GPE lines and produced tumors when transplanted into newborn guinea pigs. However, the sarcoma virus genome could be rescued in these NP cells by cocultivation with "helper" murine leukemia virus (MuLV) releasing GPE cells. Particles resembling guinea pig leukemia virus were activated from guinea pig NP cells or cultured normal guinea pig cells following chemical treatment. These particles were approximately 100 nm in the mature form and had a density of 1.16-1.17 g/ml. They contained RNA dependent DNA polymerase activity.

Animals↗
PubMed1979

Studies on the pathogenesis of experimental autoimmune renal tubulointerstitial disease in guinea pigs. VI. Induction of renal lesions by active or passive immunization of strain 2 guinea pigs.

It has been reported that strain 2 guinea pigs do not develop experimental autoimmune renal tubulointerstitial disease (RTD) by active or passive immunization. Under our experimental conditions strain 2 guinea pigs are susceptible to the induction of RTD. Typical moderate to severe renal lesions were seen 22 days after immunization with rabbit tubular basement membrane in complete Freund's adjuvant. Most Albany strain guinea pigs had severe RTD. Susceptibility to induction of RTD by passive transfer of antitubular basement membrane autoantibodies was studied in Albany (A) and strain 2 (2) guinea pigs, as well as in A leads to A, A leads to 2, and 2 leads to A radiation chimeras. Only some strain 2 guinea pigs had mild to severe renal lesions by day 9, but by day 19 all had typical histologic renal abnormalities. Albany guinea pigs already had moderate to severe RTD by days 9-10. Strain 2 differed from Albany recipients by a noticeable delay in the onset of lesions. Bone marrow transplants between Albany and strain 2 did not affect these susceptibility differences. A leads to 2 recipients responded like strain 2, and 2 leads to A like Albany. This indicates that the delay of onset of RTD in strain 2 is not a defect in the bone marrow-derived inflammatory cells.

Animals↗
PubMed1976

Comparison of guinea pig cytomegalovirus and guinea pig herpes-like virus: pathogenesis and persistence in experimentally infected animals.

The pathogenesis of guinea pig cytomegalovirus (GPCMV) and guinea pig herpes-like virus (GPHLV) in guinea pigs was compared. Animals were inoculated with the two viruses by different routes and sacrificed after varying periods of time. GPCMV was consistently isolated from salivary gland 2 weeks postinoculation and thereafter following intraperitoneal or subcutaneous incoulaton. Virus was less frequently found in other tissues including blood, spleen, and kidney. Intranuclear inclusions were seen in tissue sections of salivary gland after inoculation with GPCMV- infected tissue suspension, but were only rarely found after inoculation with tissue culture virus. In GPHLV-infected guinea pigs, consistent latent infection of leukocytes and other tissues was detected by cocultivation techniques. Intranuclear inclusions were not found in the spleen, salivary gland, or other infected tissues after GPHLV infection with either tissue culture virus or infected tissue suspension. Guinea pigs inoculated with GPCMV produced high titers of specific neutralizing antibody to the homologous virus; those inoculated with GPHLV developed long-term viremia accompanied by minimal neutralizing antibody levels to the virus.

Animals↗
PubMed1976

Guinea pig histocompatibility antigens. III. Analysis of normal lymphocyte transfer (NLT) reactions among guinea pigs with serologically defined phenotypes (GPL-AB locus and I region).

The normal lymphocyte transfer (NLT) reaction occurring upon intradermal injection of lymphocytes into a normal recipient may be considered as a kind of mixed lymphocyte reaction in vivo. In previous experiments, we have defined serologically a number of guinea pig lymphocyte antigens, controlled either by a GPL-A locus (equivalent of H-2 D locus in mice) or by a so-called I region (equivalent to the I region in mice). The I region also appears to control a number of immune response genes in the guinea pig. Using guinea pig inbred strains (such as 2, 13, OM3, BE), guinea pig families homozygous for their GPL-A antigens and serologically characterized outbreds, it has been possible to show that antigens of the I region probably play a higher role in NLT reactions. No NLT reactions occur among outbred animals of a closed colony which have been bred to homozygozity for their GPL-A antigens and thereby probably possess haplotype homozygozity for their major histocompatibility complex. The NLT reaction among serologically characterized guinea pigs may become a convenient way to detect new specificities and recombinant progeny.

Animals↗
PubMed1977

Cytotoxicity of guinea-pig lymphoid cells against guinea-pig hepatoma cells in tissue culture.

The cytotoxic effect of guinea-pig lymphoid cells on guinea-pig hepatoma cell lines in tissue culture was investigated, using the microplate technique of Takasugi and Klein (1970). The effect of lymphoid cells from guinea-pigs immunized against tumor cells was compared to that of cells from normal controls. Several ratios of effector to target cells (10 : 1, 50 : 1, 150: 1, 250 : 1) were used. In Hartley guinea-pigs immunized with allogeneic tumour cells, peripheral blood lymphoid cells from 14/16 animals showed significant cytotoxicity against that tumour in culture. In a syngeneic tumour/host system, 7/13 animals showed cytotoxicity. Spleen cells gave less consistent results in both systems. The cytotoxic activity of subpopulations of immune lymphocytes against tumour cells in vitro was investigated. It was found that although both T-cell-enriched and T-cell-depleted cell populations exhibited cytotoxicity against tumour cells, the unfractionated cell population was the most effective. This suggests that some degree of cell cooperation may be involved in the cytotoxicity. Antibody-dependent cellular cytotoxicity was also obtained. A T-cell-depleted population of normal cells was shown to be cytotoxic to tumour cells in the presence of serum from immune animals. This type of cytotoxicity could be obtained concomitantly with cell-mediated cytotoxicity in the same animals.

Animals↗
PubMed1978

Strain related infectivity of Neisseria gonorrhoeae for the guinea-pig subcutaneous chamber and the variability of the immune resistance in different breeds of guinea-pig.

The ability of gonococci to infect the subcutaneous chamber in guinea-pigs is strictly strain related. This ability was usually present in prototrophic strains and auxotrophs requiring proline only which were obtained from patients with uncomplicated gonorrhoea, but it was invariably absent in Neisseria gonorrhoeae auxotypes requiring arginine, uracil, and hypoxanthine, or arginine only for growth. All the strains obtained from disseminated gonococcal infections (all dependent upon arginine, uracil, and hypoxanthine) were unable to infect the guinea-pig chamber. Hence, the high invasiveness of N. gonorrhoeae for man and its infectivity for guinea-pig chambers appear to be unrelated properties. Although guinea-pigs of the same origin (Dunkin-Hartley) were used throughout, the degree of immune resistance was found to differ between the lines supplied by various breeders--that is, after a standard immunisation schedule using whole cell gonococcal vaccines, the homologous immune resistance to challenge varied from weak or non-existent in some lines, to highly resistant in others.

Animals↗
PubMed1979

Experimental chlamydial salpingitis in immunosuppressed guinea pigs infected in the genital tract with the agent of guinea pig inclusion conjunctivitis.

At necropsy indication of spread of infection to fallopian tubes was found in 25 of 41 (60%) female guinea pigs infected in the genital tract with the chlamydial agent of guinea pig inclusion conjunctivitis and immunosuppressed with cyclophosphamide. Eighteen were examined histologically, and the diagnosis of acute salpingitis was confirmed in 10, based on inflammatory reaction, detection of guinea pig inclusion conjunctivitis in tissue, and formation of cysts (pyosalpinx and hydrosalpinx). Infection of fallopian tube tissue was confirmed by indirect immunofluorescence and electron microscopy. Infection of endometrial tissue and peritoneum was also recognized. Data suggested that the immunosuppression mediated by cyclophosphamide resulted in a prolonged genital tract infection and concomitant ascending infection leading to salpingitis.

Animals↗
PubMed1976

Formed blood elements in peritoneal effusion and the macrophage migration inhibition test in healthy guinea pigs and in guinea pigs with experimental allergic encephalomyelitis.

An attempt was made to correlate the percentages of macrophages, lymphocytes and granulocytes in the peritoneal effusion in healthy guinea pigs and guinea pigs with experimental allergic encephalomyelitis (EAE), with the macrophage migration inhibition (MMI) test. Varying percentages of the cells had no influence on values of MMI. Similarly, in guinea pigs with EAE, percentages of formed elements in peritoneal effusion were not correlated with intensity of MMI or with histopathologic lesions in the brain and spinal cord. It is suggested that the observed differences are due to individual immunologic responsiveness of animals and, probably, to other hitherto unknown mechanisms.

Animals↗
PubMed1976

Mutant lines of guinea pig L2C leukemia. III. The reaction of an alloantiserum detecting idiotypic determinants on a clonally derived guinea pig B cell leukemia with IgM and Ia molecules.

An alloantiserum was prepared in a strain 13 guinea pig against the GH line of the strain 2 guinea pig L2C leukemia. This serum contained antibodies to both IgM and Ia molecules. After absorption with normal spleen cells from a strain 2 guinea pig, this antiserum no longer reacted with strain 2 cells, but detected idiotypes on the IgM molecules of the L2C leukemia. These idiotypes were on the same IgM molecules detected by a xenogeneic sheep anti-L2C Fab mu antiserum. As assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the idiotype-bearing IgM molecules were synthesized by the cell, composed of normal sized mu and light chains, appeared on the cell surface as monomeric IgM, and were the only immunoglobulin molecules present on the cell. Although the alloantiserum potentially contained antibodies to unique Ia idiotypic determinants, none were found. Furthermore, the anti-IgM idiotype antisera did not react with any Ia-like molecules.

Animals↗
PubMed1975

Herpes genitalis in guinea-pigs. II. Morphological studies in female guinea-pigs infected with Herpesvirus hominis type 2.

Gross and microscopial morphological changes developing in female guinea-pigs after vaginal infection with HVH 2/Angelotti were studied. In the mucosa of the external genital tract there were inflammatory changes with formation of intra-epithelial vesicles, erosions and ulcerations. In the late stages of the infection signs of inflammatory dysplasia were also observed. The infection spread into the nervous system and produced characteristic inflammatory changes. The inflammation began as a bilateral posterior myelitis and ascended in the course of infection through the upper spinal-cord towards the brain-stem. The morphological changes were preceded by increased virus replication in the respective tissues and were correlated in time with clinical symptoms. The morphological changes seen at the site of inoculation in the external genital tract of the guinea-pig bore a certain resemblance to those seen in some cases of human infection with the same type of virus.

Animals↗
PubMed1979

Inhibition by digoxin and SC4453 of (Na+ + K+)-ATPase prepared from human heart, guinea-pig heart and guinea-pig brain.

SC4453 is a digoxin analogue with a pyridazine instead of a lactone ring on C17 beta. SC4453 was compared with digoxin with respect to inhibition of (Na+ + K+)-ATPase prepared from human heart, guinea-pig heart and guinea-pig brain. SC4453 was slightly less potent than digoxin but showed a similar sensitivity to K+. As for cardenolides, species differences in sensitivity to SC4453 were accounted for by differences in the rate of dissociation from the receptors. These observations confirm that the human heart is one of the tissues most sensitive to cardiac glycosides.

Animals↗
PubMed1979

Target tissues associated with genital infection of female guinea pigs by the chlamydial agent of guinea pig inclusion conjunctivitis.

Female guinea pigs were experimentally infected in the genital tract with the strain of Chlamydia psittaci that causes guinea pig inclusion conjunctivitis. Chlamydiae were found frequently in superficial squamous epithelial cells of the exocervix, along with heavy involvement at the squamocolumnar junction. In this zone chlamydiae were observed in columnar cells, but inflammation and chlamydial inclusions were not observed in true endocervical epithelium. These observations were supported by results of immunofluorescence microscopy. Electron micrographs revealed typical chlamydiae within surface epithelial cells at the squamocolumnar junction; various stages of the growth cycle (elementary, reticulate, and intermediate bodies) were also present. Cytopathologic features were not remarkable, but peripheral distribution of organelles, rarefaction of the cytoplasm, and loss of microvilli were observed.

Animals↗
PubMed1979

Ultrastructural development of guinea pig cytomegalovirus in cultured guinea pig embryo cells.

The ultrastructural development of guinea pig cytomegalovirus (GPCMV) in guinea pig embryo cells was studied using electron microscopy. Tubular structures were found in nuclei of virus infected cells, followed by the appearance of intranuclear inclusions containing virus nucleocapsids. While some nucleocapsids were enveloped at the inner nuclear membrane, others were released into the cytoplasm where they were associated with, or within, dense matrix which was subsequently enveloped by cytoplasmic membranes to form enveloped dense virions. Dense bodies without virus capsids were formed in the cytoplasm and enveloped in a similar manner. An involvement of the nuclear pores in the release of unenveloped virus capsids from the nucleus to the cytoplasm was postulated. Evidence that the enveloped dense virions and dense bodies shared common envelope antigen(s) was obtained by immunoelectron microscopy. The similarities and differences in the ultrastructural development of GPCMV and other cytomegaloviruses are discussed.

Animals↗
PubMed1978

A comparison of the binding constant (KD) of 125I-labelled 3-(4-iodophenoxy)-1-isopropylamino-propan-2-ol obtained on beta-adrenoceptors in guinea-pig myocardial membranes, with its dissociation constants (KB) obtained on guinea-pig isolated atria and trachea.

The dissociation constant of binding (KD) of 125I-labelled 3-(4-iodophenoxy)-1-isoproplyaminopropan-2-ol (IIP) to guinea-pig myocardial membrane preparations was 2.2 x 10-8M. In pharmacological experiments with the non-labelled material and 60 min contact time, IIP produced a parallel shift in the orciprenaline concentration-response line on guinea-pig isolated tracheal and atrial preparations. The dissociation constant (KB) of IIP was 2.9 x 10-8M on atria (pA2 7.54) and 3.3 x 10-8M on trachea (pA2 7-48). These values indicate that IIP is not a selective beta-adrenoceptor blocking drug. In addition, agreement was found between the affinity constant of this antagonist for beta-adrenoceptors as determined by a direct binding study and an indirect pharmacological study.

Adrenergic beta-Antagonists↗
PubMed1977

Studies of sperm antigenicity. 6. In vivo and in vitro cellular reactivity in guinea pigs sensitized with fractions of guinea pig spermatozoa.

Normal guinea pig spermatozoa cells were homogenized by a French pressure cell. Three soluble and three insoluble fractions were obtained by ultrascentrifugation and (emulsified in CFA) were used for guinea pig sensitization. The following were observed: 1) all fractions were immunogenic except one; 2) in vivo and in vitro delayed hypersensitivity was elicited in animals immunized with these fractions; 3) two distinctive histopathologic lesions were observed in the testes of sensitized animals: lesions of orchitis type developed in animals injected with some fractions. Other fractions induced lesions of aspermatogenic type. These results correlated well with delayed hypersensitivity results obtained by in vivo and in vitro tests. Although some other spermatozoal fractions did not cause severe changes in the testes. The lack of sperm accumulation in the epididymis was obvious.

Animals↗
PubMed1976

[The effect of urine from castrated male or female guinea pigs and rats on the estrous cycle of guinea pigs and rats, respectively].

A 24-hour reduced cycle duration was observed in 5-day cyclic female rats exposed to the odor of urine from male or female castrated rats. A decrease in the duration of the period of vaginal closure, ranging from 2 to 5 days, was observed in female guinea pigs exposed to the odor of urine from male or female castrated guinea pigs. The pheromonal activity of urine in both species was concluded to be no dependent upon the gonadal function.

Animals↗
PubMed1978

[Comparative histological studies of mouth mucosa, gingiva and desmodont in normal guinea pigs and guinea pigs fed a vitamin C deficient diet].

The changes occurring in the oral mucosa, gingivae and periodontium of guinea pigs fed a vitamin C-deficient diet were determined by means of histological comparison with animals on a normal diet. The following results were obtained from the scorbutic guinea pigs: --detachment of the horny layer from the underlying epithelium, --bullous cells in the spinose and the granular layer, --formation of periodontal pockets, --reduction in number and disorientation of collagenous fibres of the periodontium associated with loosening of the molars.

Animals↗