OBJECTIVE:To establish an ion-pair RP-HPLC method for determination of the concentration of netilmicin sulfate in human serum.METHODS:The determination was performed on Luna C18 column with column temperature set at 40℃;the mobile phase consisted of acetonitrile-water (15∶85,pH 2.0,containing 10 mmol?L-1 sodium heptanesulfonate) at a flow rate of 0.8 mL?min-1.The detection wavelength was set at 205 nm.RESULTS:The linear range of netilmicin was 2～20 mg?L-1(r=0.997 6) with a recovery rate of 93.66%～96.05%.The intra-day and inter-day RSD were both less than 10%,respectively.CONCLUSION:The method is sensitive and simple with accurate and reliable results,and it is able to satisfy the requirement for the determination of serum concentration of netilmicin.

Objective To evaluate the efficacy of ultrasonically guided radiofrequency (RF) thermal ablation of hepatic carcinoma (HC) with a clustered electrode. Methods Clinical records on 245 consecutively admitted HC patients who underwent RF tissue ablation therapy were analyzed. The tumor supplying blood flow, changes of tumor size, clinical manifestation, and AFP level were analyzed. Results AFP value decreased significantly in 50% of patients one week after ablation. Tumors less than 5*!cm in diameter became avascularized 1 to 6 months after the therapy, and it was noted that all tumors shrank in size after the therapy. For tumors more than 5*!cm in diameter, RF ablation was used in conjunction with intraarterial chemotherapy and embolization. Conclusion Ultrasound guided RF thermal ablation is an effective, safe, minimally invasive technique for treating malignant hepatic tumors.

Objective　To evaluate the results and feasibility of US-guided radio-frequency(RF) ablation for the treatment of primary or secondary liver tumors.Method　180 patients with liver tumor were treated with percutaneous ultrasound-guided RF ablation.RF was applied by a frequency at 10W with an increase of 10W every other minute until 90W for a total of 15 minutes,using single or multi puncture method.After RF treatment,the α-fetoprotein(AFP) level was examined,the ultrasonograph,computered tomography(CT),biopsy were performed.Results　In those with abnormal pretreatment AFP level,1 week after RF treatment AFP returned to normal in 119/153(77.8%)patients;2-4 weeks later or after the second treatment AFP drops to normal in 144/153(94.1%) patients.Tumors failed to grow or shrank in size,some underwent liquefaction on CT and ultrasound follow-up.The biopsy results of the treated lessions showed necrosis accompanied with microvessel thrombosis.Abdominal pain disappeared or relieved in 121/142(85.2%) patients.Ascites and temporary jaundice occured in 26/180(14.4%),and 16/180(8.9%) patients,respectively.Conclusion　RF ablation is a mini-invasive,safe,effective treatment for primary and secondary liver tumor.

Objective To investigate the morphologic characteristics of neuron-like cells induced from the rat mesenchymal stem cells(MSCs). Methods The rat MSCs from bone marrow were cultured by being adhered to the culture dish.The thirdgeneration of the MSCs were induced by the neonate rat brain homogenate supernatant for 48 hours.The morphological characteristics and the ultrastructures of both non-induced and induced MSCs were observed under the inverted microscope and the electron microscope.The property of the induced cells was identified by using immunocytochemical method. Results Under the inverted microscope MSCs showed spindle or polygon-shaped cell bodies and the nuclei with one or two nucleoli were located in the middle of the cells.After the inducement the cells appeared neuron-like with axonlike and dendrite-like processes.The neuron-like cells were neuron special endolase(NSE),neurofilament protein(NF) positive and glial filbrillary acidic protein(GFAP) negative by irnmunocytochemical staining.Under the electron microscope the MSCs had plentiful cytoplasm and organelles and had an obvious nuclei containing a nucleoli.There were a lot of microvilli on the surfaces of the MSCs.The neuron-like cells had plentiful cytoplasm and irregular nuclei with one to three nucleoli.There were also plenty of microvilli on the cell surfaces.Conclusion MSCs are one kind of multipotent stem cells and can differentiate neurons with matured organelles induced by the neonate rat brain homogenate supernatant.

To investigate the effects of TGF?antisense oligodexynucleotides(ASODN) and EGFR ASODN on human rectal carcinoma cell line HR8348. Cationic liposome, lipofectamine, were selected as delivery vector HR8348 cells were treated with ASODN in vitro. HR8348 cells with or without pretreatment were inoculated into nude mice. The proliferation and DNA synthesis of HR8348 cells treated with TGF-? ASODN and EGFR ASODN were greatly inhibited, and tumorigenic rate was also greatly reduced. TGF-? ASODN and EGFR ASODN could inhibit the proliferation of human colon cancer cell line in vitro as well as in vivo, the results implicate. The potential value in colorectal cancer gene therapy.

Objective To evaluate the therapeutic effect of combined splenorenal shunt and portaazygous devascularization on bleeding esophageal varices.Methods We summarized 120 cases suffering from esophageal variceal bleeding treated by splenorenal shunt plus portaazygods devascularization,from April,1978 to April,1997.Results The operative mortality was 4.2%,no short-term postoperative bleeding,and long-term postoperative bleeding rate was 9.5%,postoperative hepatic encephalopathy rate was 4.8%.Five,ten and fifteen years survival rate were 83.6%,64.5% and 54.5% respectively. The portal hemodynamics was observed by means of Doppler flowmeter,DSA,and intraoperative portal pressure measurement in some of the patients.Conclusion The result showed that combined shunt and portaazygous devacularization not only preserve the advantage of devacularization but also decrease the portal pressure and blood volume,alleviating portal hyperhemodynamics while preserve hepatopetal blood flow to some extent.

Objective To explore the neurovascular distribution around multifidus muscles in the low back and its clinical significance via regional dissection.Methods Five cadavers were dissected in the low back.The anatomical relationships between the longissimus thoracis,iliocostalis and the start-stop,direction and position of multifidus muscles were observed.Branches,distribution and the characteristics of the erector spinae muscle,the lateral branches of spinal nerves and blood vessels were examined.Then measured the distances from the emerging point of the lateral cutaneous branches of spinal nerves to the spinous processes.Results After removed the deep fascia,the longissimus thoracis was found medially and the iliocostalis was found laterally.The muhifidus muscles located deeply to the longissimus and the iliocostalis muscles.The lateral branches of the posterior rami of the spinal nerves and the dorsal branches of lumbar blood vessels run in the multifidus muscle gaps.Conclusion The multifidus muscle gaps contain plenty of neurovascular bundles.Surgery involving the low back often takes the advantage of the gaps between multifidus muscles.Therefore,surgeons should take caution to avoid damaging the lateral branches of the posterior rami of the spinal nerves and the dorsal branches of lumbar vessels during low back surgery.

Annulate lamellae (AL) in oocytes of eel, Anguilla japonica have been observed with electron microscopy. Two types of AL have been found in the cytoplasm of these cells, one of which is the common type, characterized by a stack of parallelly arranged lamellae with annuli (or rings) as shown in figure 1, another is a rare one, which appears as alternative arrangement of parellel lamellae with annuli and membrane-like structures as shown in figures 2～4. The only difference between them is the presence of membrane-like structure in the latter. The origin and function of the membrane-like structure have not been found out yet. It is suggested that this structure might be similar to above-mentioned lamellae in origin and might be a "buffer" in function.

Objective To observe the inhibition of transforming growth factor-alpha(TGFa) anti-senseoligodeoxynucleotides on the malignant proliferation of HR8348 cell line. Methods Using the TGFa anti-sense oligodeoxynucleotides, composed of 23 and indifferent oligodeoxynucleotides, to affect the HR8348cell. By observing the cell growth inhibiton, 3H-TdR incorporation,mRNA hybridization and the cell cycleanalysis to identify the inhibiting effects of TGFa anti-sense oligodeoxynucleotides and its mechanism.Results TGFa anti-sense oligodeoxynucleotides can Inhibit the proliferation of HR8348 cell, DNA0synthesis,mRNA expression,and defer the transition period of G,/G, phase to S phase. Conclusion TGFaanti-sense oligodeoxynucleotides can inhibit the malignant proliferation of HR8348 cell effectively.

Objective To study the relationship between MRI features and pathological characteristics of the renal clear cell carcinoma,and to conduct a comparative analysis.Methods 23 patients renal clear cell carcinoma who were proved by postoperative pathology were retrospectively analyzed. The preoperative MRI findings and the postoperative pathological characteristics were compared. Results MRI plain scan showed uniform signal was seen in 2 cases, and mixed signal was found in 21 cases with cystic and necrosis. Blood was seen in 11 cases and false envelope was present in 12 cases. Dynamic enhanced scanning revealed that solid part was enhanced obviously, it was lower than the renal cortex but higher than the renal medulla in cortical phase and continued to be enhanced in medullary phase and delay phase.Postoperative pathological characteristics showed that tumor profiles were yellow-white and cystic and necrotic structures were present within tumors, blood was found in 17 cases. Endoscopic tumor cells were present in solid nests or acinar structure, and mesenchyma was rich in thin-walled vessels involved in reticular interval.14 cases were found to have false envelope.Conclusion Renal clear carcinoma MRI imaging manifestion is related to organixational srructure. MR plain scan combined with dynamic enhanced scan has very high value in the diangnodis of renal cell carcoinoma.