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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate progesterone and estrogen receptor expression in meningiomas of the CNS in dogs and cats.

Animals—8 dogs (1 of which was treated with gestrinone) and 5 cats with intracranial meningiomas and 2 dogs with spinal cord meningiomas; tissue samples were also obtained from 1 clinically normal dog and 1 clinically normal cat.

Procedure—Meningioma tissue was obtained during surgery or at necropsy; samples were processed for histologic classification and immunohistochemical evaluation of the proportion of tumor cells with progesterone and estrogen receptors. Correlation among receptor expression, tumor grade, and histologic subtypes was determined.

Results—Several histologic subtypes of intracranial meningiomas were detected among tissue samples. In the cats, all intracranial meningiomas were benign. Progesterone receptor immunoreactivity was detected in 14 of 15 meningiomas. Progesterone receptor expression was identified in > 80% of cells in 8 intracranial meningiomas (4 dogs and 4 cats) and 2 spinal cord meningiomas. In samples of malignant transitional and granular cell meningiomas in dogs, progesterone receptors were detected in 32 and 4.8% of cells respectively. In 1 cat, 38% of tumor cells had progesterone receptors. In a dog treated with gestrinone, no progesterone receptors were detected in the intracranial meningioma. Estrogen receptors were only detected in the tumor of 1 dog.

Conclusions and Clinical Relevance—Results indicate a high proportion of progesterone receptors in cells of meningiomas of the CNS in dogs and cats. Antiprogesterone treatment may have a role in the treatment of unresectable or recurrent meningiomas in dogs and cats. (Am J Vet Res 2003;64:1310–1318)

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Summary

To determine whether intrauterine transmission of Borrelia burgdorferi could exist in dogs, 10 female Beagles were inoculated intradermally with approximately 1,000 B burgdorferi on day 1 of proestrus; inoculation was repeated every 2 weeks during the gestation period. Ten female control Beagles were similarly inoculated with phosphate-buffered saline solution. Prior to the start of the study, all females and 3 males used for breeding were seronegative for B burgdorferi on the basis of results of the indirect fluorescent antibody test and immunoblot (western blot) analysis. Similarly, results of culture of blood for B burgdorferi were negative. All 20 of the females were bred naturally. Blood samples were collected weekly for serologic testing and culture. Blood samples were obtained from live pups on day 1 of life, then weekly until pups were 6 weeks old when they were euthanatized. Tissues were obtained for culture and testing by use of polymerase chain reaction (pcr). Of 10 spirochete-inoculated (si) females, 8 became infected with B burgdorferi as evidenced by spirochete culture results and/or pcr-detected B burgdorferi dna in the tissues of females or their pups. Of the 10 si females, 8 delivered litters (3 to 7 pups) that had at least 1 neonatal or 6-week-old pup with B burgdorferi dna-positive tissues (by pcr), and spirochetes were cultured from tissues from pups of 2 litters. Four pups of 3 separate litters (a stillborn, a neonate that survived to 30 minutes of age, a 20- hour-old, and a 48-hour-old) had B burgdorferi-positive tissues (by pcr), and the 20-hour-old pup was also culture-positive, indicating intrauterine infection. Further evidence of intrauterine exposure was the presence of IgM antibodies to B burgdorferi detectable by western blot in 3 of 7 one-day-old pups that did not receive colostrum, indicating a primary immune response. Eight of 10 si females and 10 of 10 control females carried litters to term. Differences between si and control Beagles were seen in the duration of gestation, number of resorptions, and number of dystocias. All control females and pups remained seronegative, culture-negative, and B burgdorfer-inegative throughout the study.

Intrauterine infection by B burgdorferi does occur in dogs and is a potential means by which the spirochete can be transmitted in a breeding population in the absence of a tick vector.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine the usefulness of a new method of measuring acoustic backscatter and attenuation in the liver of dogs with experimental steroid-induced hepatopathy.

Animals

10 clinically normal dogs.

Procedure

Steroid hepatopathy was induced by daily injections of prednisone (2 mg/kg of body weight, IM). Dogs were evaluated histologically and were sonographically imaged on days 0, 3, 7, 10, and 14. Acoustic backscatter and attenuation were measured from in vivo images of dogs, using a video signal method, and compared with results obtained from analysis of the unprocessed radio frequency signal.

Results

Histologic evaluation revealed midzonal, predominantly water-filled vacuoles in hepatocytes by day 7, which persisted for the remainder of the study and significantly (P = 0.0001) increased liver weight on day 14. Attenuation and backscatter increased during the experimental period. Mean effective attenuation difference was higher (P = 0.015) in the liver imaged through a left paraxyphoid window in experimental dogs by day 3. Significantly (P < 0.05) greater attenuation persisted in the liver of experimental dogs throughout the experimental period. Mean backscatter ratio was significantly increased (P = 0.02) by day 10. Uncorrected pixel intensity of the liver in 2 experimental dogs was approximately equal to that of the spleen on day 10 and greater than that of the spleen on day 14.

Conclusion

Administration of prednisone to dogs results in increased acoustic backscatter and attenuation in the liver.

Clinical Relevance

The video signal method is a sensitive technique for detecting subtle acoustic changes in the liver of dogs. (Am J Vet Res 1996;57:1690–1694)

Free access
in American Journal of Veterinary Research