The purpose of this experiment is to study the destiny of cancer cells and changes of lymph node after lymphatic metastasis.Ehrlich ascitic carcinoma cells were injected intradermally into the right footpad of mice. We try to estabilish a model about lymphatic metastasis in the popliteal lymph node.The lymph nodes of the drainage area were taken out at different time intervals and examined by light microscopy, transmission electron microscopy as well as scanning electron microscopy. Onehour after the injection cancer cells were found in the popliteal lymph node. Mitotic figures of cancer cells were discovered in fifth hours and the tumor cells had reached to second lymph node——lumber lymph node or parailiac lymph node. The metastasis were formed in 24 hours after injection. The tumor cells first migrated in the subcapsular sinus of lymph node, then they entered the intermediate and medullary sinuses. Besides, the lymph nodes showed active reactionary proliferation, hyperplasia of histocytes and enlargement of germinal centers after three days. There were many small lymphocytes assuming the form of active amebae, surrounding the postcapillary venules. Degeneration and necrosis of cancer cells was observed at same time.Under the electron microscope many lymphocytes were observed to adhere closely to the cancer cell and their Golgi apparatus and mitochondria were accumulated towards the cell memberane opposing the cancer cell, as if some substance were released to it.This experimental result showed that lymph node probably prosess ability to defend metastasis of cancer cells.

Objective To explore the pathological and imaging features of adenosquamous carcinoma (ASC) of pancreas.Methods Both clinical data and imaging findings in seven cases with pathologically proved ASC of pancreas were analyzed retrospectively.Imaging features were compared with pathological results.Results 1 )The disease mainly occurred in people around 55 years, among the 7 cases ,5 located in the pancreatic head, 2 in the body and tail, with abdominal pain and jaundice as the chief complaint.2)Pathologically, the solid part of the tumor was made up of ductal adenocarcinoma and squamous carcinoma components, with a different rate, while the cystic part was made up of necrosis, liquefaction.3) the imaging of 5 cases with ASC of pancreas in which squamous carcinoma components predominate shows solid and cystic tumors of pancreas, furthermore the ratio of central cystic diameter and the whole tumor diameter increase with the the volum of the tumor.4) There is no partitioning in the cystic part of the tumor, with a few irregular microcyst around it.5 ) The tumor shows a pattern of infiltrative growth, associated dilatation of the common bileduct or pancreatic duct in all cases, pancreatic atrophy in part.6) Squamous carcinoma components of the tumor was the pathologic basis for the formation of the solid and cystic structure in imaging.Conclusions ASC of pancreas is a rare aggressive subtype of pancreatic adenocarcinoma with a worse prognosis than the usual type of ductal adenocarcinoma, although symptoms similar to pancreatic ductal carcinoma.Cases of ASC of pancreas in which squamous carcinoma components predominate have certain characteristic imaging and pathologic features,which is important to early diagnosis.

Objective To study the effects of IFN-?on expression of B7 molecules in human lung adenocarcinoma cell line cultured in vitro.Methods Human lung adenocarcinoma SPC-A-1 cells were incubated in the medium with IFN-?respectively.Cell proliferation effect was measured by MTT assay;apoptosis was detected with flow cytometry assay;expression of B7-1 and B7-2 mRNA was determined by RT-PCR.Results Compared with those of control group,MTT shows that IFN-?could reduce the SPC-A-1 cell proliferation.FCM shows the apoptosis rate in the IFN-? group was significantly higher,but there is no different changes in each concentration group.Compared with the control group,expression of B7-1 and B7-2 significantly increased in the IFN-?group,and the expression was not correlated with the concentration of IFN-?in each control group.Conclusion IFN-?can inhibit cell proliferation and induce apoptosis in SPC-A-1 cell line.IFN-?markedly enhance the expression of B7-1 and B7-2 in SPC-A-1 line.The apoptosis may be mediated by up-expression of gene B7-1 and B7-2.

Objective To study on the ultrastructural characteristic of segments of photoreceptors from neonatal retinas for supporting donor retina choice of retinal transplantation. Methods Photoreceptors from neonatal calf and adult calf were analysed by scanning electron microscopy and transmission electron microscopy. Results Segments of photoreceptors from neonatal calf appeared the mushroom pattern, in which, distal end of outer segment which was ball shaped formed the head with mushrooms appea rance, and the inner segments along with some of outer segments formed the body with mushrooms appea rance. Within the outer segment, plasma membranes of adjacent evaginations form a disk subsequently. The array of most disks were vertical to the entire length of segments, but some were parallel and slope to. Owing to the incomplete formation, some rim of disk near distal end of outer segment revealed step shaped appearance. The distal end of outer segment displays some processes consisted of membranous discs, much vesicular material and mitochondria, much rough endoplasmic reticulum (RER) and numerous polysomes. Segments of photoreceptor connected with outer nuclear layer via the external limiting membrane. Conclusion The typical morphological structures of outer segments suggest the immature and strong gowth ability of photoreceptors of the retina of neonatal calf, and therefore the competence for donor material of retinal transplantation.

Cartilage is one of the earliest reconstructed tissues used in tissue engineering. Due to the lack of appropriate seeding cells, cartilage tissue engineering is, however, relatively lagged behind. With the emergence of stem cell research, adipose stem cells(ASCs) are introduced as seeding cells into tissue engineering for possessing many advantages such as wide spreading, large amount of cells available and easy to obtain. However, the outcome of tissue engineered cartilage construction by ASCs is not as ideal as that by bone marrow stem cells (BMSCs) yet. Low efficiency of ASC chondrogenesis is considered the major cause. This review summarizes the purification of adipose-derived cells, maintenance of sternness and optimization of ehondrogenie induction, which play vital roles in improving ASC s chondrogenesis.

Objective To investigate the effects of rolipram on neurofunction and the ultrastructure of the spinal cord in rats with spinal cord contusion.Methods Thirty adult,female Sprague-Dawley (SD) rats received spinal cord contusion at the T10 level.They were then randomited into an experimental group and a control group immediately after the operation.Rats in the experimental group received subcutaneous injections of 0.25mg/kg of rolipram twice daily for two weeks.Control rats received the same dosage of 0.9％ sodium chloride solution on the same schedule.The rats'functional recovery was evaluated using the open-field locomotion rating scale of Basso,Beattie and Bresnahan (BBB score),once a week within the 1st month after spinal cord injury (SCI),and once every two weeks subsequently.The morphology of the spinal cord tissue around the lesion site was observed under the light microscope with HE staining at the 8th week postoperation,and the ultrastructure of the spinal cord was observed under the transmission electron microscope at the 2nd,4th and 8th week postoperation.Results At the 2nd and 3rd week after SCI the experimental group exhibited significandy greater improvement in average BBB scores than the control group.However,the average BBB scores in the experimental and control groups were not significantly different at 8 weeks after SCI.Under the light microscope,cavities were observed in the posterior dorsal column near the SCI in both the experimental and control groups.However thick,condensed glial scars in the injured area were observed only in the control group.The density of glial cells decreased more in the experimental group than in the control group.Transmission electron microscopy revealed that,compared with the control group,inflammatory edema was attenuated and fewer axons were damaged at the 2nd week postoperation in the experimental group.That group also showed less axon degeneration as well as more angiogenesis at the 4th and 8th week.Conclusion Rolipram can reduce secondary neuron degeneration,inhibit gliosis and the formation of glial scars,and promote angiogenesis.

Objective To investigate the CT manifestations of follicular thyroid adenoma.Methods CT manifestations of follicular thyroid adenoma proved by operation and pathology in 19 cases were analyzed retrospectively.Results Of 19 cases,5 cases were male and 14 cases were female,the average age was 36.6 years old.There were single focus in 17 and multiple focus in 2.All lesions were round or round-like.The lesions were homogeneous low density with smooth clear edges on plain CT scans.2 cases showed calcification in tumor.All cases had slight enhancement on contrast-enhanced CT scans.Conclusion CT manifestations of follicular thyroid adenoma are mostly typical which appear round or round-like,with clear smooth edges and most of which can be correctly diagnosed.

Cerebellar Neoplasms ; ultrastructure ; Humans ; Medulloblastoma ; ultrastructure

BACKGROUND: Quiet a number of researches has reported the morphological changes of global ischemic reperfusion model. However, there are few reports on the ultrastructural changes of cortex in early reperfusion, especially the change of blood brain barrier.OBJECTIVE: To explore the changes of brain cortex neurons, glial cells and blood brain barrier in order to provide reliable evidence for clinical treatment.DESIGN: A randomized and controlled trial.SETTING: Department of Neurosurgery, Departnent of Anesthesia and Electron Microscope Room of Beijing Tiantan Hospital.MATERIALS: The experiment was conducted to 6 Wistar rats in Beijing Neurological Surgery Research Institute of Capital University of Medical Sciences during February 2003 to February 2004. The rats were randomly divided into two groups with one of ischemia-reperfusion group and sham operation group with 3 rats in each group.INTERVENTIONS: To prepare global ischemic reperfusion model of rats. Brain was removed from ischemic group in one hour of reperfusion and from sham operation group one hour after the operation. Electronic microscope technique was used to observe the ultrastructural changes of cortex.MAIN OUTCOME MEASURES: Ultrastructural changes of cortex.RESULTS: The neurons of cortex shrank to certain degree in the early stage of ischemic reperfusion(1 hour) . The glial cells were swollen with dissolved chromosome in nucleus and unclear nuclear membrane. The foot protrusions around blood vessel slightly swelled and separated from basement membrane. Mircro-tubes were partially dissolved.CONCLUSION: In early stage of reperfusion injury, the cortex neurons, glial cells, cellular framework and blood brain barrier already changed which suggested that the protective treatment such as reducing brain edema, protecting blood brain barrier should start as early as possible.

Objective To investigate the manifestations of MR imaging and histopathology of early postoperative normal brain, and to define the correlation between MRI and histopathology. Methods Thirty six New Zealand rabbits weighing 2.0 to 3.0 kg were divided into 10 groups according to the different postoperative days: 1 to 10 day. Six animals were in groups 3, 5, 7, 10, and 2 were in the other groups. A partial resection of the parietooccipital region was performed under the usual aseptic conditions after the animals were anesthetized intravenously with 3% pentobarbital (30 mg/kg). MR imaging procedures consisted of pre and postcontrast scanning were carried out on postoperative 1 to 10 day respectively. Brain tissue samples were obtained to be prepared for examinations immediately after MR scanning. Histopathological study was made under microscope and electron microscope. The findings of MRI were compared with pathology findings. Results (1) Surgical margin contrast enhancement on MR images could be seen 24 hours after surgery. (2) The degree of contrast enhancement increased gradually before 5 days postoperatively, and no remarkable changes were present from 5 to 10 days. (3) The disruption of blood brain barrier(BBB) is the main cause of contrast enhancement during the postoperative 3 days. After that period, mechanism responsible for contrast enhancement is the formation of neovascularity and broken BBB, an increase in the number of neovascularity play a predominant role in the contrast enhancement in normal postoperative brain tissue. Conclusion The characteristics of enhanced MRI present at the surgical margin followed a typical time course during the early postoperative period. The role of neovascularity and BBB disruption in the formation of contrast enhancement at surgical margin vary with time. Knowledge of the characteristics on postoperative MR images of the normal brain can help in differentiating benign changes from malignant gliomas residual.