[Histogenesis of leukemic changes in cows]. / Khistogeneza na levkoznite izmeneniia pri kravite.

A histopathologic study was carried out on lymph nodes and viscera of 98 cows and 28 heifers that responded positively in serologic examinations for leukosis. The animals did not exhibit clinical and paraclinical symptoms, neither were there found any morphologic changes characteristic of leukosis. There existed activation and proliferation of the reticuloendothelial tissue in the sinuses of the lymph nodes. The same response was shown by the endothelium of the capillaries in visceral organs. There was also metaplasia that concerned mainly the connective tissue cells of the lymph node trabeculas as well as the adventitial cells of the vascular walls. It was considered that the infection could be manifested morphologically as a reticuloendotheliosis. By its clinical course and morphologic manifestation bovine leukosis resembles some other virus diseases that have been systematized as "delayed virus infections'.

[Pathomorphological changes in experimental nematodiriasis of lambs]. / Patomorfologichni izmeneniia pri eksperimentalna nematodiroza po agnetata.

Pathomorphological studies on three lamb groups experimentally invaded by 5000, 10 000 and 30 000 capable of invasion N. spathiger larvae were performed. The macro- and microscopic changes of the inner parenchymal organs observed at the 18th and 60th day post invasion are described. It was established that morphological changes due to experimental nematodirosis depend both on the number of N. sathiger larvae swallowed and on the duration of their sojourn in the host organism. Lighter invasion caused slight to moderate changes mainly in the small intestines, while heavier invasion led to similar changes in some parenchymal organs (liver, spleen and kidneys) also.

[Clinico-epizootologic studies in Gumboro disease]. / Kliniko-epizootologichni prouchvaniia na bolestta Gumboro.

The disease was established on a poultry dressing combine, affecting birds at the age of three to eleven weeks. It ran its course with clinical symptoms and epizootiology that were characteristic of it. A total of 8778 birds or 10% succumbed to the disease. Its notification on a newly built poultry dressing combine made it reasonable to believe that possibility existed of its transmission through the hatcheries. The outbreak occurred almost simultaneously with the inadequate feeding that was admitted on the combine. The cyclogramme concerning the admission of birds and its strict application were shown to influence the course of the epizootic process. Clinical and epizootiological investigations coupled with virological and histopathological studies rendered it possible to draw the conclusion that the birds on the combine were affected with infectious bursitis, identified as Gumboro disease. It was established for the first time in this country.

[Histoimmunofluorescent demonstration of Br. suis in necropsy material]. / Khistoimunofluorestsentno dokazvane na Br. suis v nekropsichen material

Use was made of the direct immunofluorescence method for the demonstration of Brucella suis bacteria in paraffin and frozen histosections following the respective handling. The method was tested on necropsy material from experimentally infected test animals and spontaneously infected swine embryos. Compared with the cultural and serologic methods the histoimmunofluorescence one showed far better diagnostic possibilities. The use of the histoimmunofluorescence method is suggested along with the remaining routinely employed techniques in the laboratory practice. It will raise the effectiveness of the investigations for the demonstration of Brucella suis bacteria.