Drusen and lipid-filled retinal pigment epithelium cells in a rhesus macula

A middle-aged rhesus monkey with detailed clinical history exhibited progression of a macular abnormality with a variety of clinical drusen and pigment changes typical of the Cayo Santiago phenotype. Numerous frozen sections of one sample of the macular retina/retinal pigment epithelium (RPE)/choroid showed a single classical druse but extensive single and clustered lipid-filled RPE cells. The monkey exhibited functional outer retinal decline and an insignificant number of 'window defects' as found among signs of relatively benign human macular aging. The clinical and histologically defined results agree if lipid-filled RPE cells are included among the clinically apparent signs of drusen.     

赛乐硒对发情奶牛外周血生殖激素含量和繁殖性能的影响

选用35头处于干奶期40d、泌乳期相近和上胎平均日产奶量20kg的荷斯坦奶牛,采用完全随机区组设计分为7组,即:对照组,基础日粮(不加硒);试验组1、2、3添加亚硒酸钠,分别在基础日粮中加硒7.5mg/d、15mg/d和22.5mg/d;试验组4、5、6添加赛乐硒,分别在基础日粮中加硒7.5mg/d、15mg/d和22.5mg/d,研究赛乐硒和无机硒对奶牛发情周期生殖激素分泌和繁殖性能的影响.结果表明:赛乐硒较无机硒显著提高了发情周期促性腺激素释放激素、促卵泡素、促黄体素、雌二醇和孕酮含量,显著提高了受配率和受胎率,缩短了胎衣排出周期,促进母牛正常发情.适宜补硒量为15 mg/d.     

Antigenic and morphological differentiation of placental and intestinal isolates of Chlamydia psittaci of ovine origin.

Ewe placental and lamb intestinal isolates of Chlamydia psittaci recovered from flocks affected with ovine enzootic abortion were examined by inclusion morphology, indirect immunofluorescence (IIF) and immunoblot analysis. Chlamydiae recovered from the faeces of sheep from two flocks free of clinical disease were also examined. In cell culture ovine abortion (OA) and intestinal isolates were distinguishable by inclusion development and morphology. Similarly, in two-way IIF tests with one week mouse antisera isolates fell into two distinct groups: abortion or intestinal. Immunoblotting with convalescent sheep abortion antiserum identified 30 out of at least 40 silver staining polypeptides as antigenic both in OA and intestinal isolates. The serum produced a similar reaction pattern to the resolved proteins of each OA isolate, indicating a higher degree of antigenic conservation among these isolates. Considerable cross reactivity between the OA and intestinal isolates was identified, but the serum also showed apparent molecular weight differences between antigens of the two types in the 87-116 kDa, 38-44 kDa and 26-28 kDa regions. Furthermore, the immunoblotting analysis revealed heterogeneity among the intestinal isolates, particularly in antigens between 87-116 kDa and 38-44 kDa.     

Bovine spongiform encephalopathy: detection and quantitation of fibrils, fibril protein (PrP) and vacuolation in brain

Bovine spongiform encephalopathy (BSE) is a new disease of cattle which has considerable homology with scrapie, the archetype of the transmissible spongiform encephalopathies. Abnormal brain fibrils, called scrapie associated fibrils (SAF), are specific ultrastructural markers for these diseases. Fibril detection was compared with histopathological diagnosis in the brains of 167 cattle; 157 clinically suspect BSE and 10 clinically normal. Fibrils were detected in samples of pooled brain regions of 67/144 in which vacuolar changes of BSE were confirmed, but absent in the remaining 23 brains, in which no vacuolation was found, including those from the clinically normal cattle and 13 with alternative neuropathological diagnoses. When eight defined anatomic regions from the brains of another 22 affected cows were examined, the sensitivity of fibril detection was greater than 90% for the brain stem areas. Fibril prevalence in these areas approximated to severity of vacuolar changes. When the same defined regions from four of the affected cows were assayed for fibril protein (PrP) by western blotting, the density of immuno-labelling generally correlated with the fibril prevalence. This study confirms the specificity of fibril detection for BSE, shows that the ease of fibril detection depends on anatomic region sampled and suggests an association between PrP accumulation and vacuolar changes in certain neuroanatomic areas.     

Natural scrapie: detection of fibrils in extracts from the central nervous system of sheep

Extracts from the cervical spinal cord and from the medulla, thalamus, cerebellum and cerebral cortex of the brains of 10 sheep, histopathologically confirmed as cases of scrapie, were examined by electron microscopy for the presence of scrapie-associated fibrils. Characteristic fibrils were observed in all the extracts except for that from the thalamus of one sheep. No fibrils were found in any extracts from three control sheep. A comparison of these results with a similar study of 22 cases of bovine spongiform encephalopathy (BSE) suggests that in cases of scrapie the area of the brain chosen for the detection of fibrils is less critical than in cases of BSE, in which fibrils are more readily extracted from areas of the brain stem.     

Some serological reactions to "brucella" antigen in the horse.

Seventy-three samples of serum, from 69 horses and one zebra, were subjected to the Rose Bengal Plate, serum tube agglutination, complement fixation, and anti-equine globulin (Coombs') tests for brucellosis. Fifty-one of the samples, from 48 horses, were submitted by practising veterinary surgeons; of these, 22 samples were associated with clinical conditions which might have been due to brucellosis. Fourteen samples were from healthy horses known to have been in contact with infected cattle, and six were from horses which were known not to have been exposed to brucellosis. More reactions at accepted diagnostic levels were obtained to the anti-globulin and complement fixation tests than to the agglutination test. Two horses showed no reactions, other than inconclusive titres to the antiglobulin test, and these titres could have resulted from exposure to Brucella. Eight of nine positive Rose Bengal tests were confirmed by a reaction at diagnostic level in at least one of the other tests, but two sera showing a reaction at diagnostic level to the other tests gave a negative Rose Bengal result.