Objective To investigate the morphology and the cause of the ascending aortic aneurysm induced by ascending aorta banding. Methods Forty young Wistar rats were divided into two groups:the control group (10 rats) and the experiment group (30 rats).The rat models induced by ascending aorta banding were made.The ascending aortas were taken after operation in 3-5 months,and special staining and immuohistochemical staining technique were performed and observed under light microscope. Results The ascending aortic aneurysms were induced by ascending aorta banding of the young Wistar rats 3-5 months after operation.The occurrence of the aneurysm is 63.3%,and the occurrence of dissecting aneurysms is 36.7%.The expression of MMP-2 and MMP-3 is strong in the ascending aortic aneurysm.Conclusion The occurrence of ascending aortic induced by banding ascending aorta of the young Wistar rat is high,and the expression of MMP-2 and MMP-3 is strong.

Objective To observe the novel endothelial like cells of the marginal ear vein intima of rabbit by scanning electron microscope.Methods The marginal ear veins were obtained from male Japanese big ear white rabbits,and prepared for scanning electron microscope(SEM).The novel endothelial like cells of the marginal ear vein intima were observed.Results Between endothelial cells and basement membrane of the marginal ear vein intima of rabbit,some oval-shaped endothelial like cells were found.This kind of cells was measured,the length was(8.32?1.04)?m,width was(5.79?0.68)?m,and length/width is 1.45?0.22.The cells were connected each other by some filament structure,and the average length between two adjacent cells was(6.41?2.45)?m.Conclusion There are novel endothelial like cells in the marginal ear vein intima of rabbit.The filament structure,connected between endothelial like cells,might be a new type of cell junction.

The fresh cadavers were injected with A. B. S into the popliteal arteries. We have studied the micro-vascular structure of this skin area under scanning electron microscope. There are 5 layers of the vascular network in this skin area. They were formed by the small branches coming from either the direct or indirect cutaneous arteries. The 5 layers are as follows: The capillary network of the papillary layer. The vascular network of the subpapillary layer. The deep dermal network. The network in the subcutaneous tissue. The network in the deep fascia tissue. It is clear that each layer of the vascular network has it's -own special character.

The vascular morphological character of the microcirculation in the nail bed of the toe have been studied with the scanning electron microscope. Three types of vascular network were identified: 1) The blood vessels at the proximal two fifth of the nail bed were parallelly arranged. 2) At the middle two fifths of the nail bed, the blood vessels interwoved with each other and formed the polygonal vascular networks. 3) At the distal one fifth of the nail bed there were only a few vascular loops running in a slanting position. These loops were connected with the vascular network from the papillary layer of the skin of the toe.

Objective To culture the osteoblast of Wistar rat in vitro and study its biological characteristics. Methods With heat-cool alternative method and by way of the trysin digestion, the osteoblast cells, obtained from femoral bone of Wistar rats, were colleced and cultured with special cultural fluid in vitro. After about two weeks, cells lined up in one layer. Then cells were generationed and examined by phase contrast microscope, H E strain, ALP strain, type Ⅰ and type Ⅲ collagen strains. Results The cells had the same morphological feature with ALP activity, type Ⅰ collagen strain positive. Conclusion The cultured osteoblasts derived from bone mass were seed cells for the bony tissue engineering, which is the base for the tissue-engineering born construction in vitro.

Objective To observe the possibility of inducing mesenchymal stem cells(MSCs)to differetiate into hair follicle stem cells by the supernatant of cultured hair follicle in vitro and to investigate the transdifferentiation potentiality of MSCs. Methods MSCs were isolated and cultured from rat bone marrow by complete adherence.MSCs of passage 3 were characterized with markers CD44 and CD29 by immuohistochemical staining technique.The stem cells were induced by the supernatant of cultured hair follicle.The morphological character was observed by inverse phase-contrast microscopy.The expression of keratin 15 was detected by immunohistochemical staining technique and immunofluorescence staining technique.RT-PCR was further used to detect the expression of keratin 15. Results The isolated and separated MSCs were immunostaining positive in CD44 and CD29.After induced by the hair follicle conditioned medium in vitro,MSCS could be partially identified by the positive staining for keratin 15,a specific antibody of hair follicle stem cells.After 3 weeks′ induction,keratin 15 was detected by RT-PCR in MSCs induced by supernatant of cultured hair follicle.Conclusion MSCs have the potential to differentiate into hair follicle stem cells induced by the supernatant of cultured hair follicle in vitro.

Objective:Our purpose was to establish an ideal chronic pressure-afterload heart failure rat model which has the transition from cardiac hypertrophy to heart failure. Methods: Chronic pressure-afterload heart failure rat model was induced by gradually constricting the ascending aorta of young rats. Young rats were randomly divided into 2 groups: the constricted and sham-operated groups. Clinical manifestation, tail-cuff blood pressure, organ weight, and hemodynamic data were observed at various time after operation. Results: The overall survival rate was 87%. Tail-cuff pressure began to increase in 4 weeks after operation. Left ventricular hypertrophy appeared in 12 weeks and heart failure in 5 months. Conclusion:It's a practical and reproducible model of cardiac hypertrophy that progresses to chronic heart failure.

Objective The experiment aims at probing the best condition of the isolation and purification of rat islets. Methods The islets were isolated from rat pancreas by hepatopancreatic duct perfusing with collagenase and purified with Ficoll 400 discontinuous density gradient centrifugation.Then the purified islets were subjected to histological staining,electron microscopy and radioimmunoassay for identification of specificity and viability. Results The histological staining revealed that the viability and the purity of the purified islets were above 95% and 85% respectively.Electron microscopy showed that the purified islets were morphologically intact with clear membrane and plenty of secreting granules.Radioimmunoassay demonstrated the secreted insulin concerntration between low-glucose groups and high-glucose groups varied significantly,which verified the good function of the islets.Conclusion Hepatopancreatic duct perfusing with collagenase is a good method for digestion.There are many factors that influence the quantity and quality of the acquired islets,such as the completed expansion of pancreas,the concentration and viability of collagenase and the digested time,etc.

Objective Applying a reliable precise method to assess the mitotic index of cardiomyocytes,to disclose of disclosure the mechanism implicated in cardiomyocytes proliferation. Methods H9c2(2-1) cardiomyocytes were originally developed from rat BD1X heart(ATCC).These cells were cultured on coverslips.Double immunofluorescence staining with monoclonal antibodies(1:100) against phospho-histone H3 and ?-sarcomeric actin was performed on the cultured cells.Anti-mouse IgG FITC was used as the secondary antibody for the H3P antibody,and anti-mouse IgM Cy3 was used as the secondary antibody for the ?-sarcomeric actin.DNA was visualized with Hochest 33342.All photographs were taken with an Olympus fluorescence microscope. Results The cytoplasm of cardiomyocytes appeared red,the mitotic chromosomes green with distinct shape,and Hochest 33342-stained nuclei blue.Conclusion Our method is the reliable and exact means to observe and assess cardiomyocytes mitosis.

The cell volume, length, cross-section area, surface area, width and thickness of isolated cardiac myocytes were measured by using of a new computer system of coulter channelyzer and avias eye imaging analysis system. The rats, 3 weeks to 24 weeks in age after birth, were performed thoracic operation the morphological growth characteristics of isolated cardiac myocytes were observed.1. Physiological growth of normal cardiac myocytes was due to increase in cell volume, i. e. the cell length and cross-section area were enlarged. In the mean time, the changes in cross-section shape of myocytes happened when the myocytes growing.2. The major axis of cross-section area of myocytes was enlarged but the minor cross-section diameter did not show any more changes. So that, the growth lead to the cardiac myocytes be flattened in shape. The flattened growing pattern was one of the characteristics of normal growing myocytes. It might be very significant for the clinicians to eliminate the factors which would stimulate myocytes to be enlarged in cell width, and to treat and to prevent the heart disease.