Sequential pathologic changes and viral distribution in rabbits experimentally infected with new Korean strain of rabbit hemorrhagic disease virus (RHDVa) / 대한수의학회지

Rabbit hemorrhagic disease is a highly acute and fatal viral disease caused by rabbit hemorrhagic disease virus (RHDV). Since first outbreak in Korea 1987, RHDV has been continually affected in the country, but the pattern of outbreak seem to be changed. In this study, to understand the pathogenesis of the new RHDVa serotype, we therefore carried out to inoculate RHDVa to rabbits, and to examine the sequential histopathologic changes and viral distribution. Macroscopically, various sized dark red or white spots or appearance were observed in the liver, lung, kidney uterus and ureter. In euhanized rabbits, significant pathologic findings such as infiltration of heterophils and mononuclear cells were observed at 24 hours after inoculation (HAI), and these were sequentially extended periportal to centrilobular area. However, in dead rabbits, severe hepatic degeneration and/or necrosis with relatively weak inflammatory responses were observed. RHDV antigens began to detect in liver, spleen, and lung from 12 HAI by PCR. Immunohistochemically, RHDV positive cells were seen in only liver from 24 HAI, and the degree of immunogen reactivity was stronger in dead rabbits than in euthanized ones. In conclusion, RHDVa caused the subacute or chronic infection accompanying low mortality and moderate to severe inflammatory reaction in rabbits, suggesting the possibility that RHD could become endemic.

Muscle Fiber Conduction Velocity and Histopathologic Findings after Intramuscular Injection with 7% Phenol Solution in Rat

OBJECTIVE: To investigate the muscle fiber conduction velocity and histopathologic changes in skeletal muscle after 7% phenol solutions intramuscular injection. METHOD: Forty-five Sprague Dawley rats were divided into two groups: Experimental group, 30; Control group, 15. Experimental and control groups were injected with 0.1 cc of 7% phenol solution and 0.9% saline in right gastrocnemius, respectively. The histopathologic findings and muscle fiber conduction velocity were evaluated at 0, 1, 5, 14, and 28 days after each injection. RESULTS: In the light microscopic examination of experimental groups, vacuolar change, atrophy of myofibers, and intermyofiber cell proliferation were shown. The expression of synaptophysin began to be seen at 5 days and S-100 protein was increased 14 days after injection. In the electron microscopic examination of experimental groups, vacuolar change and denuded postsynaptic membrane were shown. In muscle fiber conduction study of experimental groups, the mean velocity were significantly slowed at 1, 5, 14, and 28 days after injection than those of control groups (p<0.05). CONCLUSION: On the basis of histopathologic findings, it is presumed that the mechanisms of paralysis following intramuscular injection of 7% phenol solutions were both myogenic and neurogenic. The slowing of muscle fiber conduction velocity tended to be related with the histopathologic changes of skeletal muscles after intramuscular injection with 7% phenol solution.

Pathologic Changes after Inferior Oblique Marginal Myotomy in Rabbits: The Effect of Triamcinolone

In the margial myotomy of inferior oblique muscle(IO myotomy), only the overaction of the muscle is eliminated and the normal action of the inferior oblique saved. Steroid is usually used to prevent the adhesion of the tissue after IO myotomy, subconjunctivally. The myotomy of IO was performed in 14 white rabbits which were divided into two groups, one group having local injection of triamcinolone after IO myotomy and the other not having it. At postoperative 1 month, there were edema of the muscle fibers and infiltration of the inflammatory cells. Three months postoperatively, ingrowth of fibrous tissue and atrophy of the muscle fibers were found. Those changes were less prominent in the group with triamcinolone injection. This study revealed that subconjunctival triamcinolone injection after the IO marginal myotomy produce a good effect on the prevention of postoperative adhesion in the long term.

Pathologic changes after inferior oblique marginal myotomy in rabbits

To evaluate the histopathologic changes after an inferior oblique marginal myotomy with local injection of triamcinolone, an inferior oblique marginal myotomy was performed in 14 white rabbits and they were divided into 2 groups, one group with a local injection of triamcinolone and the other group without triamcinolone injection after a myotomy. At the postoperative one month, an edema of the muscle fibers and an infiltration of the inflammatory cells were observed and at postoperative three months, a fibrous tissue ingrowth around the muscle fibers and an atrophy of the muscle fibers were found and those changes were less prominant in the group with triamcinolone injection. The local injection of triamcinolone after the inferior oblique marginal myotomy would help in decreasing the fibrous tissue ingrowth and the formation of the scar tissue, thus it could be used in augmenting the effect of the inferior oblique marginal myotomy.

Pathologic changes after inferior oblique marginal myotomy in rabbits

To evaluate the histopathologic changes after an inferior oblique marginal myotomy with local injection of triamcinolone, an inferior oblique marginal myotomy was performed in 14 white rabbits and they were divided into 2 groups, one group with a local injection of triamcinolone and the other group without triamcinolone injection after a myotomy. At the postoperative one month, an edema of the muscle fibers and an infiltration of the inflammatory cells were observed and at postoperative three months, a fibrous tissue ingrowth around the muscle fibers and an atrophy of the muscle fibers were found and those changes were less prominant in the group with triamcinolone injection. The local injection of triamcinolone after the inferior oblique marginal myotomy would help in decreasing the fibrous tissue ingrowth and the formation of the scar tissue, thus it could be used in augmenting the effect of the inferior oblique marginal myotomy.

Atypical Condyloma of Uterine Cervix: It's Cytological Similarity to Squamous Cell Carcinoma

Atypical condyloma is a variant of flat condyloma characterized by the presence of atypical koilocytes having large hyperchromatic, smudged and often bizarre nuclei. Atypical condyloma can be frequently misdiagnosed on cytologic smear and on tissue sections by its marked cellular atypia, as high grade dysplasia, in situ or even invasive squamous cell carcinoma. We described two cases of atypical condyloma of the female genital tract. The cytologic features and histologic changes were reminiscent of those of invasive squamous cell carcinoma and severe degree of dysplasia of the uterine cervix. The differential findings between atypical condyloma and squamous cell carcinoma were discussed in detail.