Laser-induced interstitial thermotherapy via a single-needle delivery system: Optimal conditions of ablation, pathological and ultrasonic changes / 华中科技大学学报（医学）（英德文版）

This study aimed to examine the optimal conditions of laser-induced interstitial thermotherapy (LITT) via a single-needle delivery system, and the ablation-related pathological and ultrasonic changes. Ultrasound (US)-guided LITT (EchoLaser system) was performed at the output power of 2-4 Wattage (W) for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers (n=24), and VX2 tumors implanted in the hind limbs of rabbits (n=24). The ablation area was histologically determined by hematoxylin-eosin (HE) staining. Traditional US and contrast enhanced ultrasound (CEUS) were used to evaluate the treatment outcomes. The results showed: (1) In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 min, and it extended slightly with the ablation time. (2) In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. (3) Gross examination of the liver and carcinoma showed three distinct regions: ablation crater/carbonization, coagulation and congestion distributed from the center outwards. (4) Microscopy revealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and congestion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. (5) The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effectively guide and assess the treatment.

The effect of RNA interference-mediated down-regulation of EphB4 on the growth of malignant glioma cell line U251 / 肿瘤

Objective: To determine the interfering effects of EphB4-targeted short interfering RNA (siRNA) on EphB4 mRNA expression and its effect on the growth of glioma U251 cell line. Method: EphB4-targeted siRNA was designed and synthesized, and then was transfected into U251 cells. The inhibition of EphB4 mRNA expression was detected by RT-PCR. The effect of EphB4-targeted siRNA on cell growth rate was measured by CCK-8 method. Cell apoptosis was tested by flow cytometry (FCM). Wound healing test was used to observe the migration ability of cells. The invasiveness of tumor cells was evaluated by counting the number of cells passing the Transwell membrane. Results: EphB4 mRNA transcription level was decreased by 75.0% after transfection of malignant glioma U251 cells with 100 nmol/L siRNA-EphB4. The inhibition of cell proliferation was in a dose-dependent manner. FCM analysis showed that cells were arrested at sub-G1 phase at different degrees and the migration capacity decreased after transfection with 100 nmol/L siRNA-EphB4 compared with the negative control. The number of cells permeating the matrigel membrane significantly were decreased in the siRNA-EphB4 transfection group compared with the control group. Conclusion: siRNA-EphB4 markedly targetes and knocks down EphB4 gene transcription. Down-regulation of EphB4 affects cell proliferation and induces apoptosis of cells. Transfection of siRNA-EphB4 into U251 cells inhibits the migration and invasion abilities of cells at various degrees. It indicates that silencing EphB4 expression might become a noval approach in the treatment of glioma.

Toxic effects of ammonium perchlorate on thyroid of rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of toxicity of ammonium perchlorate (AP) on thyroid of rats.</p><p><b>METHODS</b>Eighty-eight Wistar rats were treated orally with different dosages of AP. Three treated groups received 129, 257, 514 mg.kg(-1).d(-1) of AP respectively and one control group drunk water for 13 weeks. Another 3 groups received 1.2, 46.5, 465.0 mg.kg(-1).d(-1) of AP respectively and one control group drunk water for 36 weeks. The behavior and change of body weight in rats were observed. The levels of thyroid hormones in serum were measured and the pathological changes of thyroid tissue were observed as well.</p><p><b>RESULTS</b>There were no differences in behavior and change of body weight between different AP exposure time. When the rats were treated with AP 514 mg for 13 weeks, free triiodothyronine (FT3, 2.48 pmol/L), free thyroxin (FT4, 13.33 pmol/L) were lower than those in control group (3.24, 20.92 pmol/L respectively, P<0.05). Thyroid-stimulating hormone (TSH, 0.375 mIU/L), thyroglobulin (TG, 3.37 microg/L) were higher than those in control group (0.29 mIU/L, 2.00 microg/L respectively, P<0.05). When the rats were treated with AP 465 mg for 36 weeks, FT3 (2.65 pmol/L) was lower than that in control group (4.97 pmol/L, P<0.01). FT4 in 46.5, 465 mg groups (10.63, 2.17 pmol/L respectively) were lower than that in control group (15.74 pmol/L, P<0.05, P<0.01). TSH in 465 mg group (0.34 mIU/L) was higher than that in control group (0.14 mIU/L, P<0.05). Histopathologic examination showed that follicle proliferation, no colloid in follicle, gore, follicular diminishing or atresia were found in 46.5, 465 mg groups with a dose-effect relationship.</p><p><b>CONCLUSIONS</b>The toxic effects of AP on the growth of rats were not found, but those on the thyroid of rats were found significantly. Thyroid is the target organ of AP. It is considered that none effect dose of AP for rat thyroid may be 1.2 mg.kg(-1).d(-1), its threshold dose may be 46.5 mg.kg(-1).d(-1).</p>