AIM: To clarify if TA9901, a natural antioxidants, could inhibit the formation of β-amyloid (Aβ) fibril when Aβ1-40 were injected into cerebral cortex of rat brain, and explore the mechanism of action of TA9901 on Alzheimer disesse. METHODS: Twelve Wistar rats (250-300 g) were randomly divided into four groups (n=3). (1) control group; (2) TA9901 treatment group (ip 100 mg·kg-1 ·d-1); (3) Vitamin E (VE) treatment group (ip 100 mg·kg-1 ·d-1); (4) PBS group. 5 μL 0.2% Aβ1-40 was immediately injected into the right side of the deep cerebral cortex of control, TA9901 and VE group rats. The animals were sacrificed at the seventh day after the injection. The sections of the rat brain that contained the injected field were examined with transmission electron microscopy and Congo red staining with polarized microscopy. RESULTS: Many depositions of high electron density were observed by electron microscopy in the field where Aβ1-40was injected. They are intimately intermingled with macrophages and astrocytes. In the field, abou10nm fibrillar structures were observed that appeared similar to the fibrils seen in senile plaque (SP) of the brain of Alzheimer disease (AD). The fields in control and VE group contained richer Aβ fibrils than that in TA9901 group. After the sections stained with Congo red, A1-40aggregation demonstrated intense birefringence under, indication the formation of amyloid fibrils. In TA9901 group, there was a weak birefringence. CONCLUSIONS: TA9901 can inhibit the fibril formation of Aβ that was injected into deep cerebral cortex of rat brain, this indicates primarily that TA9901 may be a potential therapeutic drug to interfere with the progression of amyloidgenesis in AD. 相似文献
Gastrointestinal segments from 4 healthy, 17-, 21-, 22- and 23-day-old calves fed on whole cow’s milk were examined. Scanning electron microscopy showed that the anterior duodenum had short villi varying in shape from leaf-shaped to nodular; the middle duodenum had broad, tongue-shaped villi and the anterior, middle, and parts of the posterior jejunum had slender, finger-shaped or leaf-shaped villi. The villi of the mucosa covering Peyer’s patches in the posterior jejunum were short and either conical or tongue-shaped; there were also small “pseudovilli” caused by bulges in the lymphoid tissue. Morphometry showed that the villi were longer in the anterior jejunum than in the duodenum and the posterior parts of the jejunum (P < 0.005). Morphologically fat absorption was most heavy in the anterior third of the small intestine. Moderate amounts of fat were also found in the epithelium of the posterior jejunum and of the abomasum. Large fat droplets were seen in apical duodenal enterocytes, in contrast to the small epithelial droplets in other areas with fat absorption. Nile blue staining indicated that the fat in the large droplets was esterified. 相似文献
Out of a total of 224 bovine eye secretions, 126 Moraxella bovis and 64 Neisseria ovis strains were isolated. The pathogenesis and histological lesions caused by Neisseria ovis have been studied on the eyes of three calves naturally affected with IBK, using electron microscopy.
Neisseria ovis caused in 1–12 weeks old calves acute, transient and mostly benign serous conjunctivitis with only slight affection of the cornea. More rarely erosions and even ulceration of the cornea have been observed.
Moraxella bovis and Neisseria ovis strains proved nearly unanimously sensitive in vitro to chloramphenicol, neomycin, oxytetracyclin, nitrofurantoin, erythromycin and cefoperazone. Other antibiotics and chemotherapeutics inhibited the growth of these agents only partly or were ineffective.
Experimental therapy has been carried out using a single i.m. injection of Terramycin/LA inj. (Pfizer) in a dose of 20 mg/kg body mass, repeated if necessary after 72–96 h. This formulation proved more effective and practical than treatments used earlier. 相似文献