Pathological study of cerebral amyloid angiopathy in rat models of Alzheimer's disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine cerebral pathologies in cerebral amyloid angiopathy in a rat model of Alzheimer's disease.</p><p><b>METHODS</b>Rat models of Alzheimer's disease was established by stereotactic Aβ1-42 fiber injection in the bilateral hippocampus. The cognitive function of the rats was evaluated with water maze test. HE staining, Congo red staining and double-labeling indirect immunofluorescence were used to examine the dynamic distribution of Aβ fiber deposit in the brain.</p><p><b>RESULTS</b>The model rats showed significant differences from the control rats in the escape latency and the times of crossing platform in waster maze test. HE staining revealed a decreased number and degeneration of the granular cells with increased glial cells in the model rats. Congo Red staining showed that the Aβ fiber was deposited gradually in the small vessels in the brain parenchyma to cause thickening, stenosis or occlusion of the small vessels. Immunofluorescence staining detected Aβ fiber migration from the parenchyma to the walls of the small arteries in the rat models.</p><p><b>CONCLUSION</b>Cerebral amyloid angiopathy is a major pathological feature in Alzheimer's disease.</p>

Intraperitoneal injection via a paravertebral approach in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore a simple and reliable method for intraperitoneal injection through a paravertebral approach in rabbits.</p><p><b>METHODS</b>Sixty New Zealand rabbits were randomized into conventional group and modified groups to receive intraperitoneal injections through conventional and paravertebral approaches, respectively. In the conventional group, the injection site was on the abdominal wall 3~4 cm lateral from the umbilicus bilaterally, while that in the modified group was located dorsally at L5/L6 level 3-4 cm lateral from the midline. Abdominal CT scan was performed in the post-injection rabbits, which were sacrificed after 24 h for abdominal dissection.</p><p><b>RESULTS</b>Success with a single puncture was achieved in 13 out of the 20 rabbits in the conventional group, and the rest required at least two punctures, with a mean rank sum of 23.50. With the modified approach, a single attempt was successful in all the 40 rabbits, with a mean rank sum of 34.0, showing a significant difference between the two groups (P<0.01). The success rates of a single injection differed significantly between the two groups (P<0.01). CT scan and abdominal dissection showed that the injection site with the modified approach was far away from the vital organs and large vessels with less peritoneal hyperemia and exudation.</p><p><b>CONCLUSION</b>Paravertebral intraperitoneal paracentesis is a convenient and reliable method for intraperitoneal injection in rabbits.</p>