Treatment of thoracolumbar tumors with total en bloc spondylectomy and the results of spinal stability reconstruction / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic effect of total en bloc spondylectomy (TES) for thoracolumbar tumors and the results of spinal stability reconstruction.</p><p><b>METHODS</b>From January 2007 to June 2011 there were 18 patients with thoracolumbar tumors distributed in the thoracic vertebrae (n = 10) and lumbar vertebrae (n = 8). There were 7 haemangiomas, 5 giant cell tumors of bone, 1 malignant schwannoma, 1 solitary plasmocytoma, 1 neuroblastoma, 1 osteoblastoma, 1 metastatic malignant fibrous histiocytoma, and 1 metastasis of breast cancer. All the 18 patients were treated with improved TES under electrophysiological monitoring of spinal cord. Four patients were treated through one-stage combined anteroposterior approach and 14 patients through one-stage posterior approach. The anterior reconstructions included titanium mesh cages filled with bone or bone cement in 15 cases, titanium mesh cage with strengthened rings in 2 cases and artificial vertebral body replacement in 1 case. The posterior reconstruction included multiple segmental fixation with pedicle screw-rod system in 15 cases and short segmental fixation in 3 cases. Massive bone auto-graft was employed in 13 cases and fragmental bone graft in 5 cases.</p><p><b>RESULTS</b>The total en bloc spondylectomy was performed successfully in 15 patients and unsuccessful in 3 whose spinal tumors were resected by piecemeal technique. In 15 patients with successfully performed TES, the duration of surgery was from 340 to 610 min (average, 450.7 min), the blood loss was from 3000 to 10 200 ml (average, 4850 ml), and the intraoperative blood transfusion was from 2800 to 9600 ml (average, 4200 ml). The operation-related complications comprised hemopneumothorax, intercostal nerve pain, stress ulcer and bleeding, and so on. One year after operation, the patients with neurological dysfunction recovered from grade A to grade D in one patient, and to grade E in the other 14 cases. The average visual analog scale (VAS) scores was 0.5. One patient with plasmacytoma and another one with L5 metastatic tumor suffered progression of the disease and were living with the diseases. The patient with metastatic malignant fibrous histiocytoma died of local recurrence and lung metastasis 16 months postoperatively. One patient with L4 neuroblastoma died of other reason and all the rest were free from relapse. The Cobb angle of upper and lower vertebral body adjacent to the involved vertebrae in sagittal plane was from -26.7° to 12.0° (average, -2.57°) just postoperatively and from -17.5° to 57.2° (average, 11.5°) at the last follow-up or before reoperation. There were 2 patients with screw-rod breakdown and 2 patients with internal fixation loosening. The measurement of titanium mesh cage subsided into adjacent vertebral bodies was average 7.5 mm. The revision surgery was performed in 3 patients, through combined anteroposterior approach in 2 and only posterior approach in 1 patient.</p><p><b>CONCLUSIONS</b>TES significantly increases the therapeutic effect of spinal tumors, although accompanied with high difficulty and massive bleeding. In spinal stability reconstruction after total spondylectomy, it should be emphasized that posterior long segment fixation with pedicle screw-rod system, massive bone bridging graft and the application of thoracolumbosacral orthosis can achieve short-term firm fixation and long-term fusion-stabilization.</p>

Determination of laser energy density threshold leading to glare-induced blindness by pattern visual evoked potential in guinea pigs / 解放军医学杂志

Objective To explore the application of pattern visual evoked potential (PVEP) in examination of energy density threshold of laser beam that may lead to glare-induced blindness in guinea pigs. Methods Stainless steel bolts (5mm in length, 1.2mm in diameter), as reference electrode and recording electrode for the PVEP measurement, were implanted into skulls of 27 guinea pigs, located in 6mm proximal to bregma and 10mm distal to bregma. These guinea pigs were randomly divided into three groups with 9 (18 eyes) for each group, and they were exposed to laser beam at wave length of 635nm, 660nm and 690nm, respectively. The PVEP was recorded in each group before and immediately after laser irradiation, and also on day 2 and day 4 after laser irradiation in guinea pigs blinded immediately after laser exposure. The latency and amplitude of P wave in PVEP before irradiation was considered as control value for each group. When PVEP could not be recorded instantly after laser irradiation, the intensity of electric current applied at that time was considered as threshold value of each laser beam. The power of electricity(P) values was then calculated, and energy density threshold that led to glare-induced blindness was figured out according to currentpower curve (P-I curve). On day 2 and day 4 after irradiation, PVEP was additionally recorded, and latency and amplitude of P wave were compared with that of control values to examine the recovery of visual function of the blind guinea pigs. Results The energy density thresholds of the three laser beams at wave length of 635nm, 660nm, 690nm respectively were 356.36 10-9J/cm2, 349.58 10-9J/cm2 and 343.93 10-9J/cm2. In guinea pigs became blind after exposure to laser beams at wave length of 635nm, 660nm, 690nm, the latencies of P wave recorded 2 days after blindness were not significantly different with control value of each group(t=-0.356, P=0.729; t=0.492, P=0.633; t=-0.445, P=0.666), while the difference in amplitudes was statistically significant (t=11.01, P=0.000; t=5.223, P=0.000; t=5.702, P=0.000). Four days after blindness, the latencies and amplitudes of P wave recorded on the guinea pigs were also compared with the control values, but no statistically significant difference was found (latency: t=1.329, P=0.213; t=2.040, P=0.069; t=-0.894, P=0.392; amplitude: t=-3.030, P=0.768; t=0.194, P=0.850; t=-0.948, P=0.365). Conclusions The energy density threshold of laser beams, at length wave of 635nm, 660nm, 690nm, may lead to glare-induced blindness in guinea pigs is around 350 10-9J/cm2. PVEP examination is a useful and harmless way to determine the energy density threshold of laser beam which will cause blindness.

Separation of rod- and cone-driven oscillatory potential from retinal cone degeneration rat and congenital stationary night blindness rat / 中华实验眼科杂志

BackgroundOscillatory potentials (OPs) has been used extensively in experimental research and clinical diagnosis,but it is well known that OPs are the summating potentials originated from retinal rod and cone.To separate the rod and cone OPs is helpful for us to diagnose some retinal diseases.ObjectiveThis study was to analyze the characteristics of cone-and rod-driven OPs. Methods The retinal cone degeneration ( RCD ) and congenital stationary night blindness(CSNB) rats were used in this study and SD rats served as control,and 6 rats for each kinds of animals.Scotopic and photopic OPs were recorded in each rat under the dark adaptation for 12 hours and light adaptation for 10 minutes at the stimulate light intensities of -35,-25,-15,-5,0,5 db respectively with RETIscan Visual Electrophysical System.The scotopic and photopic OPs were extracted from flash electroretinogram (FERG) with Maflab7.0 Butterworth filtering waves,and the frequency spectrum of the OPs was analyzed by fast Fourier transform.The characteristics of OPs from RCD rats and CSNB rats were assessed and compared.Results The a wave and b wave of ERG were showed under the dark adaptation condition in both SD and RCD rats,but the b wave was absent in CSNB rat.Under the light adaptation condition,b wave was seen in both SD and CSNB rats,but a wave and b wave of RCD rat were absent.Two peaks were exhibited in both SD and RCD rats under the darkadaptation condition and high intensity of stimulate light at the lower frequency( domain frequency) of 75-110 Hz,90-120 Hz and high frequency ( minor frequency) 90- 120 Hz,110- 135 Hz respectively.In various intensities of stimulate light,CSNB rats appeared a peak at 70-100 Hz.But in light-adaptation and various intensities of stimulate light,the frequency peaks were seen at 75-95 Hz and 70-85 Hz from both SD and CSNB rats respectively.However,under the light adaptation condition,only one peak was seen in SD and CSNB rats at the 75-95 Hz and 70-85 Hz respectively.Compared with SD rats,the mean implied time of b wave was delayed and the amplitude was lowed under the light adaptation (P＜0.05 ),however,no significant differences were found in the implied time and amplitude of b wave of scotopic ERG between SD rats and RCD rats( P＞0.05 ).The scotopic OPs showed the prolong implied time and depressed amplitudes in RCD rats and CSNB rats compared with SD rats( P＜0.05 ),and the photopic OPs presented the prolong implied time and lowed amplitude in CSNB rat in comparison with SD rats (P ＜ O.05 ).ConclusionsCone- and rod-driven OPs appear very different characteristics.The results of this study imply that rod pathway gives more contribution to OPs than cone pathway.Analysis of these results will be helpful for the exploration of the origin of OPs and the diagnosis of the related disease.

Application value of 3T 1H-magnetic resonance spectroscopy in diagnosing tumors of bone and soft tissue / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study benign and malignant bone and soft tissue tumors with 1H-magnetic resonance spectroscopy (1H-MRS) at 3 Tesla MR scanner and assess the value of 1H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. METHODS; Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. 1H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 1H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds (Cho) opposite to the creatine (Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies.</p><p><b>RESULTS</b>1H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3.13 +/- 0.9 and 1.34 +/- 1.02, respectively (P = 0.02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94%, 80%, and 90%, respectively, in diagnosing malignancies.</p><p><b>CONCLUSIONS</b>The increased Cho level, as measured by 1H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. 1H-MRS can be an important supplement to the conventional magnetic resonance imaging.</p>

Analysis of curative effect for 21 recurrent soft-tissue sarcoma / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize the effect of the surgery for recurrent soft-tissue sarcoma, and evaluate the treatment strategies.</p><p><b>METHODS</b>The curative effect of 21 cases of recurrent soft-tissue sarcomas from January 2005 to March 2011 is analyzed.</p><p><b>RESULTS</b>In 21 cases, 7 cases were amputated, 12 cases were ampliative resection and 2 cases were marginal excision. The 4 cases were recurrent, metastasis and dead, 1 cases were recurrent and live with tumor, 1 cases had metastasis and live with tumor.</p><p><b>CONCLUSIONS</b>Appropriate enough surgery margine can prevent the local recurrence, and complete removal of the tumor and comprehensive radiation and chemotherapy treatment of recurrent soft tissue tumor is the key to success.</p>

Release kinetics of methotrexate loaded calcium phosphate cement and histological evaluation of the osteogenesis in rabbits / 中国医学科学院学报

<p><b>OBJECTIVE</b>To observe the release kinetics of methotrexate-loaded calcium phosphate cement (MTX-CPC) implanted in vivo and histologically investigate its resorption and osteogenesis.</p><p><b>METHODS</b>MTX-CPC consisting of 1% methotrexate (MTX) (weight/weight) was pre-set and implanted into femoral muscles of 24 New Zealand rabbits. The in vivo MTX release kinetics was determined on the 1st, 2nd, 5th, 10th, 15th, 20th, 25th, and 30th post-implantation day. The local concentrations and the residual percentage of MTX were determined. Then the pre-set MTX-CPC was implanted into femoral condyle. Calcium phosphate cement (CPC) without MTX was used as a control. The femurs were harvested at the 1st day and the 1st, 3rd, and 6th month and examined by X ray. Then histomorphometric analyses including percentage of newly formed bone and amount of osteoblast and osteoclast were performed.</p><p><b>RESULTS</b>The MTX release kinetics in vivo confirmed that MTX-CPC was a monolithic matrix system, with a burst effect in the initial stage and a sudden drop thereafter. The local concentration of the released MTX was 0.372 μg/ml on the 30th post-implantation day; with a concentration higher than the effective concentration,the incorporated MTX was expected to be continuously released over the following 2-3 months. Both MTX-CPC and CPC showed good biodegradability and osteoconduction. Although the release of MTX had an inhibitory effect on osteogenesis, especially in the initial stage, the area of newly formed bone, the amount of osteoblasts, and the amount of osteoclasts were not significantly different between MTX-CPC group and CPC group on the 6th post-implantation month.</p><p><b>CONCLUSIONS</b>MPX-CPC system is an effective drug delivery system. Both MTX-CPC and CPC has good biodegradability and osteoconduction. Therefore,MTX-CPC system can be an ideal material for filling defects and controlling local recurrence.</p>

Changes of 3-tesla 31P-MR spectroscopy of bone and soft tissue tumors / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors.</p><p><b>METHODS</b>41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr.</p><p><b>RESULTS</b>The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05).</p><p><b>CONCLUSION</b>Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.</p>

Preliminary study of 3T 1H MR spectroscopy in bone and soft tissue tumors / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Magnetic resonance spectroscopy (MRS) is one method that can examine noninvasively the alive specimen of the organ, metabolism of the organ and cell, and the biochemistry change. MRS provides the biochemistry information that may be used to diagnose tumors or differentiate the malignant tumor from benign. The objective of this study is to investigate the benign and malignant bone and soft tissue tumors by 1H-MR spectroscopy ((1)H-MRS) on a 3 Tesla MR scanner, then to assess the usefulness of (1)H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors.</p><p><b>METHODS</b>Fifty-six patients with bone and soft tissue tumors proved clinically and pathologically were examined with (1)H-MRS. (1)H-MRS was performed to study malignant musculoskeletal tumors, benign tumors and normal muscle adjacent to lesions to analyze the characteristics, and single-voxel point-resolved spectroscopy sequence was used. Proton brain exam-single voxel of (1)H-MRS which directly appeared in the spectrum, was observed to find the peak height of choline compounds (Cho) opposite to the creatine (Cr), and whether there was a Cho peak. Metabolite values were calculated automatically from the area under each metabolite peak by the Functool 3.1 software. Metabolite ratios of Cho/Cr were manually calculated. Then according to the results, it was judged whether there existed benign or malignant tumors. The Kappa statistical test was used to analyze the MRS results, the histopathology data and the surgical situation. Statistics processing was performed using the software package SPSS11.5 for Windows.</p><p><b>RESULTS</b>(1)H-MRS spectra style of bone and soft tissue tumors was different from that of normal muscle, and differences also existed between benign and malignant tumors. Choline level in malignant tumor was markedly higher than that in benign tumors. Cho/Cr in malignant tumor was higher than in benign tumor significantly (P < 0.05). The true positive rate of bone and soft tissue between benign and malignant tumors was 34/36, the true negative rate was 15/18, the false positive rate was 3/18 and the false negative rate was 2/36. Therefore in the group, sensitivity of the (1)H-MRS was 94% (34/36), specificity was 83% (15/18), positive predictive value was 92% (34/37), negative predictive value was 88% (15/17) and the accuracy rate was 91% (49/54). The MRS results and the histopathology inspection conclusions had very good uniformity. The kappa value was 0.76 +/- 0.10 (P < 0.01).</p><p><b>CONCLUSIONS</b>The increase of Cho level measured by (1)H-MRS is related to the bone and soft tissue malignant tumor. Cho/Cr in malignant tumor was higher than in benign tumor, so they will play a vital role in the diagnosis and differential diagnosis of bone and soft tissue tumors.</p>

Application of the proximal tibiofibular joint resection on the limb salvage for osteosarcoma of the proximal tibia / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the proximal tibiofibular joint resection on the limb salvage for osteosarcoma of the proximal tibia.</p><p><b>METHODS</b>Between August 1995 and January 2004, 11 patients with osteosarcoma of proximal tibia and tibiofibular joint involved underwent resection and endoprosthetic proximal tibial replacement. Seven patients were male and 4 were female. The patients ranged in age from 14 to 23 years (mean 18 years). The surgical stage were IIB.</p><p><b>RESULTS</b>The follow-up period varied from 2 to 9 years (mean 59 months). Three patients died of pulmonary metastases, 1 patient was still alive with pulmonary metastasis, 1 patient underwent amputation for local recurrence. There was 1 early skin necrosis, 2 transient palsy of the common peroneal nerve, and 2 thrombus of lower limb vein. The mean postoperative Musculoskeletal Tumor Society score of the knee joint was 70% (range 55% - 86%), the mean postoperative range of motion was 85 degrees (range 0 degrees - 120 degrees ), and the extensor lag varied from 0 degrees to 20 degrees .</p><p><b>CONCLUSIONS</b>Limb salvage for osteosarcoma of the proximal tibia with proximal tibiofibular joint resection and custom-made prosthesis reconstruction has had excellent results, however, the prevention and treatment of relevant complications should be given more attention.</p>