立体定向放射治疗在妇科肿瘤中的应用进展

立体定向放射治疗（SBRT）是近年来兴起的放疗新技术,该技术的优点在于它能够在控制正常组织剂量的前提下提高肿瘤组织的剂量。SBRT在妇科肿瘤中的应用主要集中在盆腔复发灶、腹主动脉旁转移淋巴结、远处转移灶的局部治疗,可获得良好的局部控制,甚至一些患者有长期无病生存的可能。尽管SBRT有严格的剂量限制,但放疗后野内复发灶治疗后出现严重不良反应的概率较高。SBRT可以作为局部晚期宫颈癌体外放疗结束后,因某些因素而无法实施后装治疗的替代治疗。     

Prostaglandin Synthesis in Membrane Fractions from the Rabbit Renal Medulla

In order to investigate the subcellular location of the prostaglandin synthesizing enzyme complex (prostaglandin synthetase) the distribution of this enzyme was analysed in membrance fractions from the rabbit renal medulla using an improved radioactive asay with arachidonic acid as a substrate. 3 membrane fractions were isolated and the subcellular origin of the membranes was determined by electron microscopy and by their contents of different marker enzymes. Fraction I was a plasma memberane fractin, II was a cytomembrane fraction, mainly derived from the endoplasmic reticulum and fraction III was a mitochodrial fraction. The specific activity of prostaglandin synthetase in the homogenate of rabbit renal mitochondrial fraction. The specific activity of prostaglandin synthetase in the homogenate of rabbit renal medulla was 0.1 nmol arachidonic acid converted/min per mg protein. In fraction II, the cytomembrane fraction, the specific activity was increased 2.4 times over the homogenate, the plasma membrane fraction and the mitochondrial fraction having lower activities. The results suggest that prostaglandin synthetase is located in the endoplasmic reticulum of renal medullary cells.     

Field Flow Fractionation for the Size,Molar Mass,and Gel Content Analysis of Emulsion Polymers for Water‐Based Coatings

In the present investigation, styrene‐acrylic and pure acrylic emulsions used in water‐based decorative coatings are characterized by size exclusion chromatography (SEC) and asymmetric flow field‐flow fractionation (AF4). Both the separation techniques are coupled online to multiangle laser light scattering (MALLS) and refractive index detection to investigate the molar mass properties during the course of the free radical polymerization reaction. For the acrylic emulsion, kinetic samples are taken from the reactor at fixed time intervals and analyzed. In SEC‐MALLS, unusual elution behavior is observed which is found previously for highly branched polymer species. In contrast, the AF4 fractograms indicate normal mode elution without any unusual behavior as compared to the SEC analyses. The molar masses obtained by AF4 are significantly higher compared to the SEC results. Further, AF4 is used to determine the gel contents of the kinetic samples of the acrylic emulsion and for both the acrylic and styrene‐acrylic emulsions, AF4 proves to be a robust and feasible tool allowing for improved correlations of the molecular and materials properties of water‐based polymer emulsions.

     

The Structure of Cationic Polyisoprene: Branching versus Cyclization

The structure, molecular weight, and molecular weight distribution (MWD) of polyisoprene fractions, which were obtained during the fraction of polyisoprene with broad MWD (M _w/M _n = 25.6) synthesized with ^tBuCl/TiCl₄ initiating system have been investigated. It is established that chain transfer to polymer leading to branched macromolecules is responsible for the formation of polyisoprene with broad MWD and reduced unsaturation. It is shown for the first time that unsaturation decreased while the content of head and end groups in a single macromolecule increased with increasing molecular weight of polyisoprene fraction. The unsaturated part of the polymer chain consists of presumably trans‐1,4‐units independently of the molecular weight of polyisoprene fraction.

     

The Role of Stereotactic Radiosurgery in the Management of Benign, Atypical, and Malignant Meningiomas

Stereotactic radiosurgery and fractionated Stereotactic radiotherapy (SR) offer precise localization of radiation dose (Gy) for the treatment of meningioma (M). For the multimodal treatment with preservation of function, SR is complementary to both microsurgery (S) and conventional external beam radiotherapy (XRT). The role of SR in the management of atypical and malignant meningiomas, however, remains unexplored. Fifty consecutive patients with meningioma: 18 males (60.1 +/– 2.3 years) and 32 females (56.9 +/– 2.2 years) (p = NS) received SR. Thirty-one patients had surgery 69.6 +/– 13.9 months (95% CI: 53.3–98.0) prior to SR. For patients having S, the incidence of atypical or malignant versus benign meningiomas (14 versus 17 patients) increased with age (p = 0.03). Twenty patients had XRT approximately 18 months prior to SR. For antecedent XRT, the range of doses was 3600–6400 cGy (median: 5040 cGy). Following failure of S and/or XRT, patients had SR. Compared to other series, the mean tumor volumes for SR were comparatively large: 9.8 +/– 1.3 cm³ (range 0.3–37.1 cm³). The median SR dose was 3500 cGy (range 540–5400 cGy) administered in seven fractions (range 1–30). Linear regression analysis showed a consistent method for fractionation: the number of administered fractions increased (p = 0.053) and the total dose increased (p = 0.054) with tumor size. During the interval for follow–up (17.9 +/– 2.9 months), one patient with malignant meningioma required surgery for progression 8 months after SR. In the remaining patients, post-SR MRIs showed control (unchanged or smaller tumor volume) regardless of histology. These results show that SR may provide control of M regardless of grade.     

场流分级分离及其在多糖分析中的应用

本文介绍了场流分级分离技术中分支技术：流动场流分级分离和热力场流分级分离技术的一般原理、设计情况及其在多糖分离中的应用。     

食管癌术前不均等剂量放疗效果观察

目的　对食管癌术前放射治疗的方法探讨 ,与单纯手术近、远期疗效的比较。方法　 2 3 0例中晚期食管癌患者经食管X线片、病理证实为鳞癌。随机分为术前不均等剂量放疗组 80例、常规组 80例、单纯手术组 70例 ,术前放疗组均为前后两野对穿照射。不均等剂量组 :第 1周 ,每次 4Gy ,照射 5次 ;第 2、3周 ,每次 2Gy ,每周照射 5次 ;40Gy ,15次 ,共 3周。常规组 :每次 2Gy ,每周照射 5次 ,40Gy ,2 0次 ,共 4周。休息 2周后手术。结果　全部病例随访 5年以上。不均等组、常规组、单纯手术组 1、3、5年生存率分别为85 %、5 1 3 %、43 8%;80 %、48 8%、3 6 3 %和 64 3 %、3 2 9%、2 1 4%(P <0 0 5 )。不均等组和常规组术后病理显示 ,重度放射反应分别为 49 3 %和 3 2 %(P <0 0 5 )。不均等组、常规组、单纯手术组淋巴结转移率分别为 11 7%、16%、49 2 %,术前放疗两组较单纯手术组淋巴结转移率有明显降低 (P <0 0 5 ) ,手术根治率为 85 %、78 8%、61 4%(P <0 0 5 )。结论　术前放疗使瘤体缩小 ,降低局部复发率和淋巴结转移率 ,提高了手术根治率和远期生存率 ,不增加手术难度和并发症。不均等组较单纯组缩短了疗程 ,疗效也有所提高。     

Multi-constituent synergism is responsible for anti-inflammatory effect of Azadirachta indica leaf extract

Context: Azadirachta indica A. Juss. (Meliaceaes) leaves have been used traditionally to treat swelling and rheumatism in Indian cultures.

Objective: To fractionate A. indica leaf extracts using bioactivity guided manner for identification of the active anti-inflammatory principles.

Materials and methods: Polarity-gradient sequential extracts (petroleum ether, chloroform, methanol, and water) of A. indica leaves were screened for their anti-inflammatory potential using the carrageenan-induced rat paw edema model (1?g/kg). The chloroform extract was sequentially fractionated to obtain n-hexane (F-1), n-hexane-chloroform (F-2), and chloroform (F-3) fractions and their inhibitory effect on rat paw edema was evaluated (500?mg/kg). Inhibitory effect of F-2 on granuloma formation, plasma interleukin (IL-1), and tumor necrosis factor (TNF-α) was assessed at the doses of 100, 200, and 400?mg/kg using the cotton pellet assay in rats. Three sub-fractions (SF-1, SF-2, and SF-3) were obtained upon chromatography of F-2, and their inhibitory effect on cyclooxygenase was assessed at 200?µg/mL concentration. The sub-fractions were subjected to gas chromatography–mass spectrometry (GC-MS).

Results: All the extracts showed significant anti-inflammatory effect; however, chloroform extract was the most effective against paw edema (53.25% inhibition). The three fractions of chloroform extract showed significant effect, while F-2 being the most potent (51.02%). F-2 demonstrated dose-dependent inhibition of granuloma and cytokines. Interestingly, all the sub-fractions of F-2 inhibited COX-1 and COX-2 with almost equal potential. GC-MS revealed that chemically the sub-fractions were totally different from each other.

Discussion and conclusion: Anti-inflammatory effect of A. indica is a result of cumulative and synergistic effects of diversified constituents with varying polarities that collectively exert the effect via suppression of cyclo-oxygenases and cytokines (IL-1 and TNF-α).     

Hypofractionated Whole-Breast Radiotherapy: Impact on Departmental Waiting Times and Cost

Conventionally fractionated breast radiation therapy is delivered over 5–6 weeks. Randomised evidence has shown that hypofractionated whole-breast radiotherapy (HWBRT) over 3 weeks results in similar local control without increased toxicity. HWBRT is not standard practice in Australia for all eligible women. We examined the effect of using HWBRT (for eligible patients) on waiting lists and monetary costs. We identified factors associated with prescribing HWBRT. The Princess Alexandra Hospital Radiation Oncology Database was searched for all women with breast cancer treated with adjuvant radiotherapy in 2008. Included patients had undergone breast conserving surgery and had T1-2N0 tumours with negative margins. Women with large breasts and those receiving nodal irradiation were excluded. The outcome evaluated was fractionation schedule. Patient, tumour and treatment factors associated with the use of HWBRT were examined. The impact on departmental resources and health-care costs were calculated assuming the entire cohort received HWBRT. Two hundred seventy-nine patients met the inclusion criteria. Sixty-seven (24%) of these patients were treated with HWBRT. Compared with the conventionally fractionated breast radiation therapy group, the HWBRT group were older (median 69 vs. 54 years; P < 0.001) and more likely to have smaller tumours (12 mm vs. 15 mm; P = 0.02). Had all eligible patients received HWBRT an extra 14 patients each month could be treated and health-care costs would be reduced by 24%. HWBRT was more frequently prescribed in older women with small tumours. More widespread use of HWBRT would allow significantly more patients to be treated each month with considerable cost savings.