The value of combined application of both ECG-gated cine MRA and 3D-CEMRA in the detection of large intracranial aneurysms was evaluated and the findings were compared with those of conventional MRA and DSA. Twenty-four patients with 26 large intracranial aneurysms underwent MRI and DSA. All these aneurysms, diameter from 15 to 39 mm, were located at internal cerebral artery (n=12), vertebral artery (n=3), basilar artery (n=4), anterior cerebral artery (n=2), middle cerebral artery (n=2), anterior communicate artery (n=2) and posterior communicate artery (n=1). Thirteen cases of hematoma or cavernoma were studied as control group. All patients were examined on GE 1. 5T MR system. ECG-gated cine MRA was performed with 2D multi-phase fast gradient-recalled echo sequence in a single section. All the images were analyzed with signal intensity VS time curve for differentiating intraaneurysmal blood flow from static tissue. The results were analzsed by statistic “t” test. 3D-CEMRA was performed with spoiled gradient-recalled echo and one dose of Gd-DTPA. All data was processed with multi-plannar reformat (MPR) and tomography for the demonstration of aneurysms in detail. All 26 aneurysms were demonstrated successfully by combined application of both cine MRA and 3D-CEMRA. Compared to DSA and conventional 3D-MOTSA, its sensitivity and specificity figures were both 100%. Cine MRA could differentiate the blood flow from the static tissue. The intensity VS time curves of intraaneurysmal blood flow offered fluctuating form and average signal change between systole and diastole period was about 89.8±37.4; However, under the control group, intraaneurysmal thrombus or cerebral hemorrhage or cavernomas had no significant signal change and the curves offered steady form with the average signal change being about 8.2±6.3. There was statistically significant difference between the intraaneurysmal blood flow and static tissue (P=0.025, <0.05). 3D-CEMRA was very useful in demonstrating the aneurysmal size, intraaneurysmal thrombus formation, neck and the detailed relationship of the aneurysm to the surrounding structures. It was concluded that the combined application of both cine MRA and 3D-CEMRA might be a valuable clinical tool for the detection of large intracranial aneurysms.
The compounds from the root ofRhododendron molle G. Don were isolated, purified by various chromatographic techniques, and their structures were identified according to the physical and chemical features and spectral data. Three compounds were separated from the root ofRhododendron molle G. Don and identified as Rhodojaponin-III,taraxerol, β-sitosterol for the first time.
The effects of different concentrations of vascular endothelial cell growth factor (VEGF) on the fibrovascular ingrowth into rabbits hydroxyapatite orbital implant were investigated. Twelve New Zealand white rabbits were divided into 3 groups and received hydroxyapatite orbital implant surgery in their right eyes. Before and after the operation, the implants were treated with 10 ng/ml VEGF, 100 ng/ml VEGF, or normal saline as control group. The animals received technetium bones scan at 2, 4, and 6 weeks postoperatively. The mean radioactivity counts within region of interest (ROI) of the surgery eye (R) and the non-surgery eye (L) in the same animal were tested, and the R/L ratios were calculated. The implants were harvested at 6th weeks and examined histopathologically. The results showed that at second week, there was no significant difference in mean R/L ratios between VEGF group and control group (F=2.83,P=0.111); At 4th week (F=7.728,P=0.011) and 6th week (F=7.831,P=0.011) postoperatively, the mean ratios in VEGF groups were significantly higher than that in control group. At 6th week postoperatively, the fibrovascularization rates in VEGF groups were higher than in control group significantly (F=8.711,P=0.008). It was suggested that VEGF could promote the fibrovascular ingrowth into hydroxyapatite orbital implant, thus might shorten the time required for complete vascularization of the HA orbital implant.
To determine the characteristics of magnetic resonance (MR) signals of normal growing cartilage and identify the difference in transverse relaxation times between physeal and epiphyseal cartilagein vivo, 24 distal femora of 12 two-week-old pigiets were imaged on a 1. 5 Tesla GE MR scanner. Comparison was made between signal intensity on MR images and the structure shown in corresponding histologic sections. T2 values were measured in eight piglets by means of multiecho spin-echo sequences. Our results showed that MR imaging delineated five regions between the secondary ossification center and the metaphysis, which histologically correspond to the zone of provisional calcification of the secondary ossification center, physics of the secondary ossification center, epiphyseal cartilage, physis and zone of provisional calcification. The T2 value in the physeal cartilage was much larger than that in the epiphyseal cartilage (P<0.05). It is concluded that MRI findings could differentiate the different regions of growing cartilage. T2 is longer in physeal than in epiphyseal cartilage, perhaps reflecting differences in water binding by proteoglycans.
In order to investigate the relationship between sex dysplasia and sex determining region Y (SRY) gene, 8 patients with sexual abnormality were analyzed by cytogentic and molecular genetic methods. Fluorescencein situ hybridization (FISH) using PY3, 4, X alpha satellite, and SRY probes was performed in each ease to analyze the sex chromosome translocation and gene translocation. SRY gene was amplified by polymerase chain reaction (PCR) and its mutation was detected by direct sequencing. The results showed that among 8 patients, 5 were positive for SRY and the remaining negative for SRY. In the patients positive for SRY genes, 3 presented testes and the left 2 streak ovaries. In the patients negative for SRY, only one case presented testes. while 2 ovaries. Direct sequencing demonstrated that all SRY genes were normal in the patients positive for SRY gene. FISR technique demonstrated that SRY genes translocated from Ypter to Xpter in 246 XX phenotypic males positive for SRY genes. It was concluded that SRY gene is strongly involved in male sex determination, while a sequence of other genes may be taken into account in sexual development.