Objective To study isolation and identification and culture of rat type A spermatogonial cells in vitro.Methods Percoll discontinue density gradient centrifugation combined with different speeds of different cells adhering to dish was used to purify the type A spermatogonial cells.The c-kit and TERT special antibodies were used to identify the type A spermatogonial cells.The purified cells were cultured in vitro. Results 0.614?10~6 cells per testis finally were obtained and the percentage of viable cells was 92.1% by trypan blue dye exclusion test.The percentage of type A spermatogonial cells expressing c-kit and TERT were 91.7?1.2% and 90.8?1.0% respectively.Type A spermatogonial cells could proliferate and self-renew in the DMEM containing 10% NBS.Conclusion Percoll discontinue density gradient centrifugation combined with different speeds of different cells adhering to dish is an efficiency method for isolation of rat type A spermatogonial cells.The purified cells are type A spermatogonial cells by identification of the immunohistochemistry of c-kit and TERT antibodies.Type A spermatogonial cells can proliferate and self-renew in vitro.

Objective To sum up the imaging features of tuberous sclerosis.Methods CT and MRI findings of brain in 20 patients with tuberous sclerosis proved by clinic,imaging or pathology were retrospectively studied. Results Among 20 cases,on CT,the lesions appeared as subependymal calcified noduli in 16 cases (multiple noduli in 14 cases and single nodule in 2) and subependymal uncalcified noduli in 2,the noduli were 2~12 mm in diameter,2 cases were normal.On MRI,the subependymal noduli were multiple in 19 cases and single in one case,the noduli were iso-or hypointensity on T1WI and iso-,hypo or hyperintensity on T2WI.In addition,the lesions within cortical or sub-cortical matter were demonstrated by MRI in 19 cases,and the abnormal signals were showed in local patterns of cortical tubers.The abnormal findings of white matter were radial linear or wedge-shaped or irregular type in 7 cases.The subependymal noduli were enhanced,and the most of cortical lesions were not enhanced after contrast-enhanced MR scans in 9 cases.Conclusion There are characteristic findings of tuberous sclerosis both on CT and MRI.

ObjectiveTo evaluate the role of perfusion weighted magnetic resonance imaging ( PWMRI ) in distinguishing brain glioma recurrence for postoperative radiotherapy patients.Methods Thirty-five patients with suggested recurrent brain glioma (20 true,15 false) were examined by conventional MRI and PWMRI.Regions of interests (ROI) were manually drawn in contrast-enhancing lesion,surround edema region and normal white matter of contra-lateral brain on regional cerebral blood volume (rCBV) images.rCBV values of ROI and rCBVmax were measured,the standardized rCBV ratios were calculated,The mean rCBVmax ratio were compared between two lesion types with group t-test.The rCBVmax ratios of contrastenhancing regions was analyzed by the receiver operating characteristic curve.ResultsThe mean rCBVmax ratio of contrast-enhancing lesion in tumor recurrence was higher than those in non tumor recurrence (4.36vs 1.28,t =3.00,P =0.005 ).The mean rCBVmax of edema regions in tumor recurrence was also higher than those in non tumor recurrence ( 1.79 vs 0.85,t =2.41,P =0.026).Four patients with recurrent tumor and three with non tumor recurrence were wrong diagnosed when set the recurrent tumor rCBVmax ratio ＞2.15.The diagnostic sensitivity,specificity and accuracy for recurrent tumor by PWMRI were 80％respectively.Conclusion PWMRI examination is a useful method for distinguishing brain glioma recurrence.

Objective To observe the changes of behavior, intracellular free calcium and the expression of calmodulin dependent protein kinase Ⅱ(CaMKⅡ) in the hippocampal neurons of chronic forced swimming stress rats. Methods Male Wistar rats were randomly divided into control group and chronic forced swimming stress group. The behavior was examined using sucrose preference test, open-filed test and Morris water maze. The intracellular free calcium was examined by fluorescence spectrophotometer. The expression of CaMKⅡ was detected using colloidal gold immunoelectron microscopy technique, Western blotting and RT-PCR. Results The consumption of sucrose and erect quantity of chronic forced swimming stress group were lower than those of control group(P<0.01, P<0.05). The escape latency time in Morries water maze test of chronic forced swimming stress group was higher than that of control group(P<0.01). The intracellular free calcium level and the expression of CaMKⅡ in the hippocampus was higher than that of control group(P<0.01).Conclusion The lasting dysfunction of Ca~(2+)/CaMKⅡ signaling cascades in hippocampus may play important roles in the pathogenesis of chronic forced swimming stress rats.

Objective To explore the MRI appearances of tuberculosis of myelon and spinal meninges,and to study the value of MRI in diagnosis of this disease.Methods The imaging appearances of tuberculosis of myelon and spinal meninges tuberculosis in 8 cases were reviewed.All cases underwent plain MRI and contrast-enhanced MRI examinations.Results In 8 cases,there were myelonic tuberculosis in 3,myelonic tuberculosis accompanied with spinal meninges tuberculosis in 2 and spinal meninges tuberculosis in 3.Myelonic tuberculosis appeared as intramedullary tuberculous granuloma in 2,granulitis in 1 and tuberculous myelitis in 2.The appearances of MRI were spinal cord swelling,low signal intensity on T1WI and high signal intensity on T2WI.On contrast-enhanced MRI,the lesions were circular enhancement,military nodules or non-enhancement.The typical MRI appearances of spinal meningeal tuberculosis showed spinal meninges generally thickened,narrowing or closing of subarachnoid cavity,on contrast-enhanced MRI,the lesions were tubiform enhancement of sagittal images or circular enhancement of axial images.All cases had active tuberculosis in neighbourhood organ or tissue.Conclusion The MRI appearances of tuberculosis of myelon and spinal meninges are representative,the definite diagnosis of which can be made when the MRI appearances in combination with the history of the patients and the active tuberculosis of neighbourhood organ or tissue.

Objective To summary MRI findings and its diagnostic value of Balo's concentric sclerosis .Methods Brain MRI images of 4 cases with Balo's concentric sclerosis were studied with review of the literature in 13 cases.Results MRI showed multiple ring-like lesions within brains in 16 patients and single lesion only in 1.The deep white matters of cerebrum were involved in all patients.The cerebellum and brain stem were invaded in 2 and 4 respectively. Typical concentric sclerosis lesions demonstrated alternate middle and low signal rings on T1WI, middle and high on T2WI. The ring-like lesions were best seen on T1WI. The middle signal rings were enhanced on post-contrast images.The typical multiple sclerosis lesions were seen in 7 patients. Conclusion Balo's concentric sclerosis has characteristic findings on MRI.MRI is a very reliable diagnostic methed for this disease.

Objective To summarize imaging appearances of brain in AIDS patients,as to supply the evidences of imaging diagnosis for this disease . Methods CT or/and MRI appearances of brain in 19 patients with AIDS of nervous system type were reviewed . Results 3 cases showed the symmetry signal abnormal in bilateral whiter matter and 2 cases showed brain atrophy in 5 patients with HIV encephalitis.2 cases of toxoplasma encephalitis appeared multiple abnormal density or/and signal intensity in the brain and multiple ring enhancement . 3 patients with lymphoma displayed single or multiple nodule in the brain and nodular-enhancement or inhomogenous enhancement.3 patients with brain infarction displayed lower density in the basal ganglia on CT.2 patients with progressive multifocal leukoencephalopathy displaied multiple patch abnormal signal intensity of the white matter in frontal and parietal lobus.1 patient with cryptococcal infection showed abnormal signal and ring enhancement of the pons.1 patient with cryptococcal meningitis and 2 patients with intracranial hypertension had not abnormal imaging appearances.Conclusion Most lesions of the brain in AIDS patient may be detected by CT and MRI,but the definite diagnosis is still in need of combining with clinical appearances and other relative examination.

Objective To evaluate the role of magnetic resonance angiography ( MRA ) in diagnosing peripheral hemangioma andvascular malformation . Methods 61 cases of hemangioma and vascular malformations in peripheral soft tissue were undergone MRAexamination.Results Of 13 patients with hemangioma,the arteries within hemangioma were increased and gradually fine from proximal to distal in 7 cases and in company with arteriovenous fistulae in 2 cases,there were no arteries within hemangioma in 6 cases.Vascular malformations were found in 48 patients,arteries and veins of vascular malformation were showed in 35 cases,but arteries of vascular malformations were only showed in one case.Arteries of vascular malformation were showed in 5 cases and the arteries were pressed on arterial angioyraphy in 23 cases.On MR venography(MRV),the shallow malformed veina were showed in 25 cases and in company with deep malformed veina in 13 cases,only the shallow and deep veina increased and thickness be showed in 2 cases.Arterioveinous fistulae could be seen in 8 cases on MR aterio-venography.There were no vessel be showed in 12 cases within the losions.Conclusion MRA is of significant value in diagnosis and differential diagnosis of peripheral hemangioma and vascular malformations.

Objective To study the manifestations and diagnostic value of MRI for cavernous hemangioma in maxillofacial region.Methods Thirty-one cases of cavernous hemangioma in maxillofacial region proved pathologically were retrospectively analyzed.Results The lesions localized in parotideomasseteric region in 13 cases,in buccal and zygomalicotemporal region in 12 cases,in orbital area in 3 cases and labium in 3 cases.The lesions appeared as ellipse or round-like in 3 cases,fusiform in 2 cases,mass or flat irregular shape in 26 cases.On MRI,20 cases showed long T1 signal intensity,4 cases were slight long T1 and 7 cases were equal T1;on T2WI,27 cases showed high signal intensity and 4 were slight signal intensity.Conclusion The diagnosis of cavernous hemangioma in maxillofacial region can be verified and the shape,the extent of lesion can also be showed by MRI.It provides a reliable basis for clinical diagnosis and operative plan.

Objective To sum up MRI and MR venography features of the dural sinus thrombosis (DST).Methods The findings of MRI and MR venography in 20 patients with DST were retrospectively analysed.Results MRI showed the normal flowing void of the dural sinus disappeared,instead of the abnormal high signal intensities.The easily involved positions respectively were transversal - sigmoid, superior sagittal and straight sinuses. Some cortical drainage and large internal cerebral veins were also involved . MR venography demonstrated that there were no blood flowing in these involved dural sinuses or veins . The locations of these lesions in MRI were same as that in MRV.Conclusion Because the DST can be directly displayed in MRI and MR venography,they are the most reliable methods of non- invasive diagnosis of DST.