BACKGROUND:Ricin possesses strong cytotoxicity but lacks of specificity.Severe adverse reactions can be caused if ricin is systemically administered.Interstitial chemotherapy with ricin coated by a sustained-release carrier can enhance local therapeutic effects of tumor,avoiding systemic-toxic occurrence.OBJECTIVE:To prepare injectable and biodegradable thermosensitive poly(D,L-lactide-co-glycolide)(PLGA)-polyethylene glycol(PEG)-PLGA copolymer-based hydrogels and to observe the in vitro drug delivery of the PLGA-PEO-PLGA copolymer hydrogel as a sustained-release carrier of ricin.DESIGN,TIME AND SETTING:A controlled observation was performed at the Center for Medical Bioengineering.Fujian Medical University between August and December 2007.MATERlALS:Ricin with a purity of 95%was purified by Fuiian Institute of Ultrasonic Medicine.DL-lactide and L-glycolide were provided by Glycolide Lactide Co.,Ltd..China.METHODS:PLGA-PEG-PLGA-copolymer was synthesized by ring-opening polymerization.MAIN OUTCOME MEASURES:Phase transition temperature was determined by test tube turnover.relativemolecular mass by high-performance gel permeation chromatography,the proportion of block copolymer by nuclear magnetic resonance spectrometry.the in vitro drug delivery of ricin coated by PLGA-PEG-PLGA copolymcr hydrogelby enzyme linked immunosorbent assay.the structural integrity of released ricin by high-performance liquid chromatography,the cytotoxicity of released ricin by methyl thiazolyl tetrazolium assay.RESULTS:The synthesized copolymer PLGA-PEG-PLGA exhibited reverse.thermosensitivity.The phase transition temperature of the copolymer was 26℃at 230 g/L.The weight-average molecular weight and number-average molecular weight of this copolymer was 8 027 and 6 643,respectively,and the multiple-dispersion toefficient was 1.17.The block ratio for PEG and PLGA was 3:2.Drug-loaded PLGA-PEG-PLGA hydrogel could release ricin in vitro for a total of 18 successive days and simultaneously well maintain cytotoxicity and the structural stability of ricin.CONCLUSION:PLGA-PEG-PLGA copolymer is an ideal carrier for sustained delivery of ricin

ObjectiveTo assess the clinical value of ultrasound-guided percutaneous ethanol injection (PEI) in the treatment of hepatocellular carcinoma (HCC) combined with portal vein tumor thrombosis (PVTT).MethodsNinety HCC patients with different type PVTT underwent ultrasound-guided PEI once or twice a week.The follow-up lasted 12 to 60 months,and the 1-,2-,3-,4- and 5-year survival rates were calculated.ResultsThe median survival time of HCC combined with PVTT patients treated with PEI was 12 months,and the 1-,2-,3-,4- and 5-year survival rates was 52.22％,23.33％,15.56％,12.22％ and 10.00％,respectively.The survival rate correlated significantly to the type of PVTT.The lower the type of PVTT was,the longer the patients lived.ConclusionUltrasound-guided PEI is a safe and effective method for the treatment of HCC combined with PVTT,and can prolong the survival time of HCC patients with low type PVTT.

Objective: To evaluate the safety and efficacy of intratumoral injection of polylactic-co-glycolic acid (PLGA) microspheres containing cobra venom cytotoxin in nude mice with transplanted human hepatoma. Methods: Cytotoxic activity of cytotoxin from cobra venom was determined by using methyl thiazolyl tetrazolium method in vitro. Microspheres containing cobra venom cytotoxin were prepared with a double emulsion-solvent evaporation method. Forty BALB/c nude mice were inoculated subcutaneously in right flank with hepatoma BEL-7404 cells. Thirty-two mice whose tumor size reached about 1.0 cm in diameter, were randomly assigned into normal saline group, blank microsphers group, cytotoxin group and cytotoxin-PLGA group. Nude mice were intratumorally injected with normal saline, blank microspheres, cytotoxin or cytotoxin-PLGA microspheres respectively. Internal echo characteristics and blood flow of tumors were observed by high-frequency ultrasound every week after treatment. Twenty-six days after treatment, the tumors were removed to calculate the inhibition rate of tumor growth. The tumor, heart, liver and kidney tissues were obtained for histopathological examination. Results: The cytotoxin separated and purified from crude cobra venom caused intense cytotoxic effects to the BEL-7404 cells in vitro. The diameter of PLGA microspheres containing cobra venom cytotoxin was about (34.45+/-9.85)mum. Encapsulation rate was up to (78.13+/-8.92)%, and cumulative amount of cobra venom cytotoxin released from the PLGA microspheres in vitro during 30 days was up to 84.3%. After intratumoral injection, tumor volumes and weights in the cytotoxin-PLGA group were lower than those in the normal saline group, with a tumor growth inhibition rate of 52.36%. Observed under a light microscope, most tumor tissues were necrotic. No obvious morphological change could be seen on the liver, kidney and heart tissues. Conclusion: The above findings indicate that intratumoral injection of cytotoxin-PLGA microspheres has strong antitumor effect and can obviously lessen systemic toxicity, which may provide an effective and feasible method for hepatocellular carcinoma treatment.

Objective To observe the effects of family cognitive training on patients with vascular cognitive impairment but without dementia.Methods Sixty patients with non-dementia type vascular cognitive impairment were divided at random into a group which received family cognitive training (30 cases) and a control group (30 cases).The 2 groups all took routine drugs and exercise.The family cognitive training group received cognitive training additionally.Before treatment and after 1 and 6 months of treatment,all of the patients of both groups were assessed using the mini-mental state examination (MMSE),the Montreal cognitive assessment (MoCA) and the modified Barthel index (MBI).Results After 1 month of treatment there was no significant difference between the 2 groups in any of the assessments.After6 months the scores on each item of the MMSE,MoCA and MBI had improved significantly more in the family cognitive training group than in the control group.Conclusion Family cognitive training is effective in treating non-dementia type vascular cognitive impairment.It can delay disease progression and improve cognitive function and ability in the activities of daily living.

Objective To investigate the ultrasonic characteristics of invasive micropapillary carcinoma(IMPC) of breast and the metastatic lymph nodes,and to evaluate the value of ultrasonography for preoperative TNM staging.Methods The ultrasonic characteristics of 16 IMPC and 81 invasive ductal carcinoma (IDC) confirmed by pathology,as well as the metastatic lymph nodes were analyzed retrospectively.The TNM-staging for IMPC by preoperative ultrasonography was evaluated according to pathology.Results Compared with IDC group,the masses showed higher A/T ratio (＜ 0.7),larger maximum diameter,more calcification,unclear border and lymph node metastasis rate,while less acoustic halo in IMPC group.Meanwhile,similar ultrasonic characteristics,such as irregular shape,uneven internal echo,spiculate margin,posterior acoustic attenuation and internal blood flow were seen in IMPC and IDC groups (P ＞0.05).According to pathology,the ultrasonic coincidence rate for T staging was 56.3 ％,and T2-staging was 85.7％.The sensitivity,specificity,positive predictive value and negative predictive value of ultrasonic diagnosis on lymph node metastases was 70.0％,83.3％,87.5％ and 62.5％,respectively.Conclusions Ultrasonography displayed more typical malignant signs,higher lymph node metastasis rate and diagnosis accuracy for IMPC,which possessed certain value for preoperative TNM staging.

Objective To investigate the features of quantitative analysis and parametric imaging of contrast-enhanced ultrasound (CEUS) in renal clear cell carcinoma (ccRCC).Methods Ninety-seven pathologically confirmed ccRCCs underwent conventional ultrasound and CEUS.Both quantitative parameters and dynamic vascular pattern (DVP) reconstructure were analyzed with Sonoliver software.Four types of DVP curves were described with type Ⅰ (Unipolar +),type Ⅱ (Bipolar + /-),type Ⅲ (Bipolar -/+) and type Ⅳ (Unipolar-),while the DVP parametric images,similarly,were divided into four types,with type Ⅰ,Ⅱ,Ⅲ and Ⅳ,respectively.Results As for the parameter of CEUS,there were statistical differences in maximum intensity (IMAX),area under the curve (AUC) and mean transit time (mTT) (P ＜0.05) and no statistic differences in rise time (RT) and time to peak (TTP) between ccRccs and peripheral renal parenchyma.Concerning of DVP of ccRCCs,type Ⅰ,Ⅱ,Ⅲ and Ⅳ accounted for 58.8％ (57/97),11.3％ (11/97),10.3％ (10/97) and 19.6％ (19/97) respectively.As for each type in DVP parametric images,the percentages were 58.8％ (57/97),11.3％ (11/97),8.2％ (8/97),21.7％ (21/97),respectively.Conclusions Quantitative analysis and parametric imaging can depict different features of vascularity in ccRCCs and improve the diagnosis of the tumors.

Objective To investigate the usefulness of acoustic radiation force impulse (ARFI) elastography for noninvasive evaluation of liver fibrosis in rats.Methods A total of 70 male Wistar rats were included in the group for dimethylnitrosamine (DMN)-induced liver injury,and 10 saline-injected rats were used as normal control.Hepatic injury was induced by a single intraperitoneal injection of DMN at a dose of 50 mg/kg of body weight.Several rats in the group with DNM injected and the normal control group were randomly selected and sacrificed at each of the following post-injection time:day 5,7,10,14,21,24,and 28.And their livers were taken for pathology analysis.All the rats underwent ARFI elastography before sacrificed in order to acquire a shear wave velocity (Vs) to represent liver stiffness.Correlation between Vs and the histological finding was analysed.ResultsAmong 58 successfully modeled rats,9,13,14 and 12 rats were found to be with S1,S2,S3 and S4 of liver fibrosis pathologically,respectively.And 10 rats were found to be with severe inflammatory activity without any fibrosis.Values of Vs increased with the stage of liver fibrosis ( P ＜0.05).There was a significant correlation between Vs and stage of liver fibrosis ( r =0.947,P =0.000).The areas under ROC curve for the diagnosis of fibrosis S≥S1,S≥S2,S≥S3 and S=S4 were 0.983,0.995,0.999 and 0.964,respectively;for the cutoff values of Vs were 1.59 m/s,2.13 m/s,2.33 m/s and 2.51 m/s,respectively,the sensitivity was 95.8％,92.3％,100％ and 84.6％,and specificity was 100％,100％,96.9％ and 95.6％,respectively.The values of Vs in the group with severe inflammatory activity were significantly higher than those in the control group ( P =0.000).ConclusionsARFI has a relatively high value in the evaluation of liver fibrfosis in rats,while severe inflammatory activity may affect its accuracy.

Objective To assess the value of echo tracking(ET) technique on atherosclerosis in the rabbit models, and to probe the pathological foundation of its indexes changes and the usefulness in evaluating arterial elasticity. Methods Thirty New Zealand rabbits were divided into 3 groups randomly: group A was the control group;group B,C were fed with high lipid feedstuffs for 8 weeks and 12 weeks, respectively. The ET examination of abdominal aorta was performed in group A and group B at the end of 8 weeks,it was performed in group A and group C at the end of 12 weeks. The parameters of elasticity were measured including pressure-strain elastic modulus (Ep), stiffness parameters(β), pulse wave velocity (PWVβ), augmentation index (AI), arterial compliance (AC), etc. Two dimensional ultrasound and pathological examination of abdominal aorta were performed at the same time. Results No obvious plaque and arterial wall thickness were seen in the abdominal aorta. Ep,β,PWVβ of group C were higher than that of group A and B, while AC of group C was lower than that of group A and B, and the difference had statistical significance (P<0.05). AI had no significant difference in all groups (P>0.05). Pathological examinations indicated that foam cell formation was seen in the abdominal aorta intima, the elastic fiber layer and smooth muscle layer were kept well in B group. Lots of cholesterol crystal formation was seen in the abdominal aorta intima and the two layer were obvious destroyed in group C. Conclusions ET can detect the atherosclerosis earlier than two-dimensional ultrasound. ET can detect the elasticity changes only when the elastic fiber layer and smooth muscle layer were destroyed . So it can be concluded that the destroy of elastic fiber layer and smooth muscle layer may be the pathological foundation of ET elasticity parameters changes.

Objective To prepare a sustained-delivery of paclitaxel-loaded thermosensitive hydrogel for the treatment of breast cancer by ultrasound-guided intratumoral injection,and probe the antitumor effect and mechanism of the new method. Methods Paclitaxel-loaded thermosensitive hydrogel was prepared. A total of 40 rats bearing subcutaneous breast tumor were randomized into 4 groups. Each group of rats were administered ultrasound-guided intratumoral injection of different agents as follows: salin, thermosensitive hydrogel, paclitaxel injection and paclitaxel-loaded thermosensitive hydrogel. The tumor nodules were scanned by high frequence ultrasound. The rats were sacrificed on the 14th day,and then the tumors were stripped to calculate the growth inhibitory rate. Histological examinations were undergone and RT-PCR was performed for the detection of bcl-2 and bax expression. Results Greater decrease in average tumor weight was found in paclitaxel-gel group [(16. 04 ± 2. 82)g], compared with that in paclitaxel group [(27.45 ±5.13)g, P ＜0. 05],and tumor growth inhibitory rate in the group was 62.77 %. In this group, blood flow signals reduction was detected on ultrasound and extensive necrosis was found in histological examination. In addition,down-regulation in bcl-2 mRNA expression and up-regulation in bax were found. Conclusions Ultrasound-guided percutaneous intratumoral injection of paclitaxel-loaded thermosensitive hydrogel may provide an effective method for breast tumor ablation therapy. The mechanism may be related to the inhibition of proliferation and induction of apoptosis.

Objective To study the impact of ultrasound contrast agent with different doses or imaging modes on rabbit spermatogenic cell in the diagnosis of radiation dose.Methods Thirty-three New Zealand white rabbits were randomly divided into 3 groups.In group Ⅰ ,three minutes gray scale ultrasound radiation was performed for three rabbits.In group Ⅱ, SonoVue was bolus injected from ear vein for eighteen rabbits.The rabbits in this group were divided into 6 sub-group according to different doses and different sampling times, the single injections of SonoVue with dosage of 0.1 ml/kg(A1, A2) or 1 ml/kg (C1 ,C2) and repeated injections with dosage of 0.1 ml/kg interval 15 min (B1 ,B2) were taken.In group Ⅲ ,twelve rabbits were bolus injected with SonoVue and then the agent bubbles were blasted when the SonoVue suffused the whole testis.The rabbits in this group were divided into 4 sub-groups according to different doses and different sampling times, and the dosages of SonoVue were 0.1 ml/kg(D1, D2) and 1 ml/kg(E1,E2).Testis were drew immediately or 24 hours later for the observation under light microscope and transmission electron microscope.Results Apoptotic cells in group Ⅲ were more than those in group Ⅰ and Ⅱ ( P ＜0.05) ,while no significant difference of the total number of apoptotic cells between group Ⅰ and Ⅱ ( P ＞0.05).The appearances of focal ultra-structural damage were observed by transmission electron microscope in group C1, such as intercellular space widening and mitochondria swelling, and no distinct damage were observed in the other groups.The appearances of intercellular space widening, mitochondria swelling and cellular edema were observed by transmission electron microscope in group Ⅲ, and spotty necrosisetc was also observed in group D1 and E1.Conclusions Large dose of contrast agent could cause germ cells slight instantaneous effects, while conventional dose had no effect.Contrast agent blasting may cause germ cells unrecoverable damage.