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patients immediately upon collection. Data on the storage of caprine whole blood is limited, so blood that is collected but not utilized cannot reliably be saved for later use. Establishing the storage life of caprine whole blood would enhance guidance for

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

The distribution and characteristics of lymph vessels in caprine hemal nodes were studied after glutaraldehyde fixation and epoxy resin embedding. Histologically, the lymph vessels were characterized by thin walls and wide lumens containing inspissated lymph in which a few cells were suspended. The lymph vessels contrasted sharply with adjacent blood sinuses that were filled with elements of circulating blood. A circumferential lymph vessel in the cortex joined radial branches in the medulla that met at the hilum to drain through a large efferent lymph channel. Ultrastructurally, the lymph vessel wall comprised endothelial cells supported by a continuous basal lamina, collagen fibrils, and adventitial reticular cells. The cytoplasm of endothelial cells had fenestrations, plasmalemma-associated vesicles, vacuoles, and focal splits that enclosed large compartments. Many compartments contained erythrocytes and lymphocytes. Modifications of the endothelial cells signified their endowment with features that favored transendothelial transport. The distribution of lymph vessels and the finding of only efferent lymph channels are related to the roles of hemal nodes in blood storage by hemoconcentration and in immune defense mechanisms.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To establish immortalized caprine fibroblastic cell lines permissive for replication of small ruminant lentiviruses.

Animals

Carpal synovial membrane explants collected aseptically from a surgically delivered fetus of a lentivirus-seronegative goat.

Procedure

Immortalization of goat embryonic fibroblasts was performed by DNA transfection with plasmids coding for simian virus 40 large T antigen. The generated cell lines were phenotypically characterized. Cytogenetics, growth pattern, and sensitivity to viral infection were studied.

Results

3 cell lines, designated TIGEF, mMTSV-54, and mMTSV-93, were generated. They had a more rapid doubling time than did fibroblasts from which they were derived, and retained morphologic and phenotypic fibroblastic characteristics. They were immortalized but not transformed because tumor formation was not promoted after their SC injection into athymic nude mice. The 3 cell lines were susceptible to caprine arthritisencephalitis virus and visna-maedi virus infections, and supported a complete virus replication cycle.

Conclusions

Cultured caprine fibroblastic cells were immortalized, using simian virus 40 large T antigen. The TIGEF, mMTSV-54, and mMTSV-93 immortalized cell lines were permissive to in vitro small ruminant lentivirus replication.

Clinical Relevance

Because lentivirus detection, as well as detailed studies of host-lentivirus interactions, are hampered by differences in viral susceptibility of each primary culture, permanent cell lines are essential tools for such analysis. (Am J Vet Res 1997;58:579–584)

Free access
in American Journal of Veterinary Research

Summary

Goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. Of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. This prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. Such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. Prevalence was highest in western Pacific and northern plains regions, increased with age to 3 years, was highest among goats on family-owned farms, and was lowest in the Angora breed. Differences in prevalence were not related to gender or size of herd.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether monocyte-derived macrophages from Mouflon-domestic sheep hybrids (Ovis musimon X Ovis spp) were susceptible to productive infection with caprine arthritis-encephalitis virus (CAEV) in vitro and whether experimental inoculation of Mouflon-domestic sheep hybrids with a molecularly cloned CAEV would result in persistent infection.

Animals—5 Mouflon hybrids.

Procedure—Macrophage monolayers were inoculated with virus in vitro. Three animals were inoculated with virus intratracheally.

Results—Productive replication of CAEV was demonstrated in monocyte-derived macrophages following in vitro and in vivo inoculation. Titer of infectious cytopathic CAEV produced by macrophages from the Mouflon hybrids was similar to titers produced by macrophages from an infected goat or by synovial membrane cells. Isolation of virus from monocytederived macrophages and use of a semiquantitative polymerase chain reaction assay to amplify a portion of the viral genome demonstrated persistent virus replication in all 3 inoculated animals. Two weeks after inoculation of sheep, approximately 1 of 5,000 monocytes was harboring the virus.

Conclusions and Clinical Relevance—Results indicate that Mouflon-domestic sheep hybrids are susceptible to infection with isolates of CAEV that cause infection in domestic small ruminants. (Am J Vet Res 2000;61:456–461)

Full access
in American Journal of Veterinary Research

Summary

One hundred eight milking goats from a dairy that had been using a modified caprine arthritis-encephalitis virus (caev) eradication program were tested for caev antibodies by serologic methods and for proviral caev dna by use of polymerase chain reaction (pcr) technology. All goats were free of clinical symptoms of caev infection. Twenty-seven of the 108 goats were considered seropositive, on the basis of elisa results. Proviral caev dna was detected, using pcr techniques, in mononuclear leukocytes in blood samples obtained from 25 of the these 27 seropositive goats. Twenty of the 81 seronegative goats also had positive pcr test results. Ten of these goats seroconverted by 8 months later, and virus was readily isolated from mononuclear leukocytes in venous blood samples after the goats had seroconverted. Virus was also isolated from mononuclear leukocytes in blood samples collected from 4 of 11 goats that were seronegative, but had positive pcr test results. These results indicated that seroconversion can be delayed for many months following natural infection with caev. Delayed seroconversion appears to be a feature of caev infection, which may have direct implications for caev eradication programs and epidemiologic studies that rely on serologic methods to detect infected goats.

Free access
in American Journal of Veterinary Research

SUMMARY

Log-linear methodology was used to examine relations among caprine arthritis-encephalitis virus (caev) seroreactivity and host/management factors in a cross-sectional study of 2,826 goats on 13 California dairies. The caev serologic status was associated with age and feeding method (pasteurized/unpasteurized milk), but not with breed. Data from a prevalence survey of 321 goats from 2 additional dairies demonstrated very good fit of the selected log-linear model (P = 1.00), indicating that the model was very appropriate to describe the relations. Odds of seropositivity and odds ratios were generated by use of a logit model derived from the log-linear model. Goats raised by the unpasteurized feeding method were estimated to have been 3.3 times more likely to be caev-seropositive than goats fed by the pasteurized method, when adjusted for the effects of age. Goats aged 2, 3, 4, and 5 or greater years were estimated to have been 1.7, 2.6, 4.5, and 5.7 times, respectively, more likely to be caev-seropositive than were yearling goats when ratios were adjusted for pasteurization status. Breed, gender, and herd of origin were not associated with caev seroreactivity when the effects of other factors were considered. Estimated odds of caev seroreactivity and the associated odds ratios for combinations of factor levels are reported. In this study, the magnitude and direction of the associations among caev serologic status, age, and pasteurized feeding methods were demonstrated.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of caprine arthritis- encephalitis virus (CAEV) infection on expression of interleukin-16 (IL-16).

Animals—-6 goats experimentally infected with CAEV and 6 age-matched healthy uninfected control goats.

Procedure—-Peripheral blood mononuclear cells (PBMCs) and synovial membrane cells from infected and control goats cultured with or without phytohemagglutinin were analyzed for IL-16 mRNA by use of a reverse transcriptase-polymerase chain reaction assay with goat-specific primers, after cloning and sequencing of a 384-bp fragment of the goat IL-16 gene. Synovial fluid, serum, and culture supernatants of PBMCs and synovial cells of control and CAEVinfected goats were analyzed for IL-16 by use of an ELISA.

Results—-The 384-bp product was 86% homologous to the corresponding human IL-16 nucleotide sequence. Higher expression of IL-16 mRNA in PBMCs (unstimulated or stimulated with phytohemagglutinin) was detected in samples from CAEVinfected goats, compared with control goats, but the difference was not significant. Synovial membrane cells infected in vitro had higher expression than uninfected control cells. Higher IL-16 concentration was detected in synovial fluid, serum, and culture supernatants of PBMCs of infected goats than in samples from control goats.

Conclusions and Clinical Relevance—Infection with CAEV increases expression of IL-16, a proinflammatory and chemotactic cytokine. This cytokine appears to be constitutively expressed at low concentrations in normal uninfected PBMCs and synovial membrane cells. Increased production of IL-16 in CAEV infection may partly be responsible for increased lymphoid cell infiltrations observed in arthritic joints and other tissues of CAEV-infected goats. (Am J Vet Res 2002;63:1418–1422)

Full access
in American Journal of Veterinary Research

SUMMARY

The core protein and the transmembrane protein, encoded for the structural genes gag and env, respectively, of caprine arthritis-encephalitis virus were amplified by use of polymerase chain reaction, cloned into a pGEX-2T vector, and expressed in Escherichia coli as fusion proteins with the glutathione S-transferase at their C-terminus. The recombinant proteins were purified and evaluated by use of an elisa. Sera from 269 goats were tested, and the results were compared with those obtained by use of immunoblot analysis. When results from both recombinant elisa (r-elisa) were compared, it appeared that the transmembrane glycoprotein was more immunoreactive than the core protein, because it was recognized by a higher percentage of sera from infected goats. When results of the 2 elisa (p28 r-elisa and p40 r-elisa) were combined in parallel, they were comparable to those of the immunoblot test, with sensitivity of 100% and specificity of 98.3%. It was also found that use of both r-elisa makes it possible to compare the variable immunoreactivity against gag and env viral antigens, which may be correlated with the disease state. The r-elisa, using core and transmembrane proteins, appears to be highly sensitive and specific for detection of antibodies against caprine arthritis-encephalitis virus.

Free access
in American Journal of Veterinary Research

Summary

Incidence of seroconversion to caprine arthritis-encephalitis virus (caev) was determined for 1,194 goats on 11 dairies, using 2 repeated annual herd tests for caev. Current life table methods were used to compare age-specific incidence of seroconversion for pasteurized milk-raised and unpasteurized milk-raised goats. Logistic regression models were used to determine the risk factors associated with caev seroconversion, and to estimate odds ratios for seroconversion for various factor levels. Goats raised by unpasteurized milk-feeding methods were 2.5 to 6.7 times more likely to seroconvert than were goats raised by pasteurized milkfeeding methods, depending on the method of comparison. Similarly, 61.6 to 85.0% of seroconversions in yearling goats possibly were attributable to unpasteurized milk feeding. Among yearling goats, caev seroconversion was associated with feeding method, breed, and source of goat (herd of origin) when the effect of dairy was considered. In addition to the 6.7 times greater risk of seroconversion for unpasteurized milk-raised goats, yearling goats of the Saanen and Toggenburg breeds were 2.2 and 3.3 times, respectively, more likely to seroconvert than were Alpine yearling goats. Yearling goats purchased from another source were less likely to seroconvert than were yearlings raised on the dairy where they were studied. Among goats > 1 year old, age was associated with risk of seroconversion. Goats that were 3 years old or were ≥ 4 years old were 1.7 and 3.2 times, respectively, more likely to seroconvert than were 2-year-old goats, when adjusted for effect of dairy. The effects of dairy were significant (P ≤ 0.001) in yearling and older goats.

Free access
in American Journal of Veterinary Research