Simulation of dose distribution in bone medium of 125I photon emitting source with Monte Carlo method / 北京大学学报(医学版)

OBJECTIVE@#To present a theoretical analysis of how the presence of bone in interstitial brachytherapy affects dose rate distributions with MCNP4C Monte Carlo code and to prepare for the next clinical study on the dose distribution of interstitial brachytherapy in head and neck neoplasm.@*METHODS@#Type 6711,125I brachytherapy source was simulated with MCNP4C Monte Carlo code whose cross section library was DLC-200. The dose distribution along the transverse axis in water and dose constant were compared with the American Association of Physicists in Medicine (AAPM) TG43UI update dosimetry formalism and current literature. The validated computer code was then applied to simple homogeneous bone tissue model to determine the affected different bone tissue had on dose distribution from 125I interstitial implant.@*RESULTS@#125I brachytherapy source simulated with MCNP4C Monte Carlo code met the requirements of TG43UI report. Dose rate constant, 0.977 78 cGy/(h×U), was in agreement within 1.32% compared with the recommended value of TG43UI. There was a good agreement between TG43UI about the dosimetric parameters at distances of 1 to 10 cm along the transverse axis of the 125I source established by MCNP4C and current published data. And the dose distribution of 125I photon emitting source in different bone tissue was calculated. Dose-deposition capacity of photons was in decreasing order: cortical bone, spongy bone, cartilage, yellow bone marrow, red bone marrow in the same medium depth. Photons deposited significantly in traversal axis among the phantom material of cortical bone and sponge bone relevant to the dose to water. In the medium depth of 0.01 cm, 0.1 cm, and 1 cm, the dose in the cortical bone was 12.90 times, 9.72 times, and 0.30 times of water respectively.@*CONCLUSION@#This study build a 125I source model with MCNP4C Monte Carlo code, which is validated, and could be used in subsequent study. Dose distribution of photons in different bone medium is not the same as water, and its main energy deposits in bone medium surface, so we should consider the effect of bone medium when we design the target area adjacent to the bone tissue in 125I sources implantation plan.

Experimental study of Solanum nigrum on inhibiting angiogenesis in chick chorioallantoic membrane / 中国中药杂志

<p><b>OBJECTIVE</b>To study the inhibitory effect of Solanum nigrum on angiogenesis.</p><p><b>METHOD</b>We examined the effects of S. nigrum on angiogenesis in the chick chorioallantoic membrane (CAM) model. On day 7 of chick embryo incubation, three concentrations of S. nigrum aqueous extracts were applied to CAMs, and their effects were evaluated on day 9.</p><p><b>RESULT</b>The angiogenesis area was significantly smaller in the CAM treated with S. nigrum than that in the control group (P < 0.001). Pathology analysis indicated that less angiogenesis occurred in the tissue of CAM under the filter paper treated with S. nigrum and the structure of large arteries was destroyed. The surrounding CAM showed a few angiogenesis formation. However, in the control group, a number of angiogenesis were observed.</p><p><b>CONCLUSION</b>S. nigrum could inhibit the angiogenesis on CAM.</p>

Diffraction enhanced imaging of condylar cartilage of osteoarthritic rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To observe the images of early lesions of condylar cartilage of osteoarthritic rats in synchrotron radiation diffraction enhanced imaging (DEI).</p><p><b>METHODS</b>The animal model of temporomandibular joint osteoarthrosis was established in rat following the method of partial resection of the joint disc. The changes of osteoarthritic condylar cartilage in different pathological stages were observed by DEI and compared with those in situ histopathological sections.</p><p><b>RESULTS</b>With DEI, straight and orbicular lines were detected in condylar cartilage 45 to 60 days after discs resection. The lines were confirmed by histopathology to be collagen degradation and tiny fissure formation inside the cartilage.</p><p><b>CONCLUSIONS</b>DEI is capable of imaging the early stages of pathological changes of excised condylar cartilage such as collagen degradation and tiny fissure formation, and this technique is of potential value to clinical application.</p>

Review about mechanisms of anti-cancer of Solanum nigrum / 中国中药杂志

This paper gave a brief introduction of the effect of Solanum nigrum on anti-cancer. The experimental results showed that the total alkaloid isolated from S. nigrum interfered structure and function of tumor cell membrane, disturbed the synthesis of DNA and RNA, changed the cell cycle distribution, so that total alkaloids could play in inhibabition to tumor cells, while the glycoprotein (150 x 10(3)) isolated from S. nigrum might have shown anti-cancer abilities by blocking the anti-apoptotic pathway of NF-kappaB, activating caspase cascades reaction and increasing the production of nitric oxide.

Development of measurement and control technologies for hyperthermia treatments of tumors with AC magnetic field / 中国医疗器械杂志

Hyperthermia therapy with AC magnetic field heating magnetic nanoparticles is a new kind of treatment method. The paper reviews the research progresses about AC magnetic heating setups for hyperthermia therapy measurements of magnetic field temperature control, and so on.

Preparation of magnetoliposomes and its in vivo behavior on ICR mice / 药学学报

<p><b>AIM</b>To prepare magnetoliposome (MLP) containing dextran-encapsulated magnetite (Fe3O4), and to examine its physicochemical properties and its in vivo behavior on ICR mice.</p><p><b>METHODS</b>Reverse phase evaporation method was used to formulate MLP and the Fe2+ concentration was measured by o-phenanthroline method. Then the basic properties of MLP and in vivo distribution were studied with the aid of 3H isotope as biomarker.</p><p><b>RESULTS</b>The mean diameter of MLP was 602.5 nm and the final concentration of encapsulated Fe3O4 was 88.1 mg x L(-1). Under natural conditions most of the MLP was taken up by spleen after the administration via tail vain, but its uptake was reduced under the magnetic field. There was a great difference in vivo distribution between the left and right lobes of the liver and the left and right kidneys in magnetic fields.</p><p><b>CONCLUSION</b>Reverse phase evaporation method was utilized to prepare magnetoliposomes. The formulation was stable and encapsulated high amount of magnetite. The delivery system could be oriented to certain tissues under magnetic field and satisfying magnetic responsiveness was observed.</p>

Primary investigation of space mutated tumor cells / 中国康复理论与实践

@#ObjectiveTo search for a new method of anti-tumor immunity,using mutated tumor cells by spaceflight.MethodsTumor cells were carried in the Shenzhou 4 and the recoverable satellite No.18.After 7 days and 18 days spaceflight respectively,the effects of spaceflight were investigated primarily.Results2382 and 1 strains of mutated tumor cells from the airship No.4 and the recoverable satellite No.18 had been obtained respectively. Comparing with the control group, the growth rate of mutated cells decreased, moreover, the secretion of cytokines also changed.ConclusionSpaceflight may affect physiological characteristics of tumor cells, and that, there was a negative correlation between the ratio of surviving cells and carrying time.