组织相容性复合物DQ基因与胰岛素依赖型糖尿病易感相关性剂量效应规律的研究

为研究中国北方汉族人中组织相容性复合物ＤＱ（ＨＬＡ－ＤＱ）基因与胰岛素依赖型糖尿病（ＩＤＤＭ）遗传易感性相关的剂量效应规律，采用聚合酶链反应和序列特异性寡核苷酸探针杂交技术，对５４例胰岛素依赖型糖尿病患儿和４０例正常成年供血员ＨＬＡ－ＤＱ基因进行了研究。结果：携带４个易感性基因的个体只见于患者，携带３个易感性基因的个体在患者中为３３．３％，正常对照中为１０％；携带２个或１个易感性或保护性基因的个体在正常对照中频率较患者为高，但差异无显著意义；携带３个保护性基因的个体只见于正常对照。提示：ＩＤＤＭ易感性基因具有部分隐性遗传的特点且具有累加效应。个体中１个或２个易感性基因的存在不能对ＩＤＤＭ构成显著的易感性，３个或３个以上易感性基因的存在方可对ＩＤＤＭ构成显著易感性。ＤＱ保护性基因具有部分显性遗传的特点并且也具有累加效应。携带１个或２个保护性基因的个体患ＩＤＤＭ的机会将大大减少，而携带３个保护性基因的个体则可以不发生ＩＤＤＭ。     

Radiation tolerance of the cochlear nerve at the γ-knife in rabbits

Since the first treatment of acoustic neurinoma using the γ-knife by Leksell, a series of cases have been reported with good control rates. However, the most frequent complication is delayed hearing loss which occurs in more than 50% of patients. The purpose of this study was to define a safe dose by analyzing the radiosurgical dose-response relationship and histological effects on the normal cochlear nerve in rabbit. The rabbits had computed tomography (CT)-guided stereotactic radiosurgery on their cochlear nerves in the internal auditory canal with a 4 mm collimator focusing of a γ-unit. Maximum doses of 10, 20, 30, 40, 60, 80, 100, 200 and 500 Gy were administered. After the radiosurgery, auditory brain stem responses (ABR) and the behavior of the rabbits were evaluated periodically. At the conclusion, histological investigations were performed. No physiological or histological findings were observed from doses of 30 Gy or below during the 12 month period after the radiosurgery. A dose of 100 Gy caused a severe ABR threshold elevation, vestibular dysfunction and facial palsy. Necrosis and demyelination of nerves were observed pathologically. In this study, we determined that the safe dose to the normal cochlear nerve during radiosurgery was under 40 Gy in rabbits, and complications seemed to vary due to individual differences in radiation tolerance.     

Three-dimensional visualization and measurement of conformal dose distributions using magnetic resonance imaging of bang polymer gel dosimeters

: The measurement of complex dose distributions (those created by irradiation through multiple beams, multiple sources, or multiple source dwell positions) requires a dosimeter that can integrate the dose during a complete treatment. Integrating dosimeter devices generally are capable of measuring only dose at a point (ion chamber, diode, TLD) or in a plane (film). With increasing use of conformal dose distributions requiring shaped, noncoplanar beams, there will be an increased requirement for a dosimeter that can record and display a 3D dose distribution. The use of a 3D dosimeter will be required to confirm the accuracy of treatment plans produced by the current generation of 3D treatment-planning computers.

: The use of a Fricke-infused gel and magnetic resonance imaging (MRI) to demonstrate the localization of stereotactic beams has been demonstrated (11). The recently developed BANG polymer gel dosimetry system (MGS Research, Inc., Guilford, CT), based on radiation-induced chain polymerization of acrylic monomers dispersed in a tissue-equivalent gel, surpasses ther Fricke-gel method by providing accurate, quantitative dose distribution data that do not deteriorate with time (6, 9). The improved BANG2 formulation contains 3% N,N′-methylene-bisacrylamide, 3% acrylic acid, 1% sodium hydroxide, 5% gelatin, and 88% water, where all percentage are by weight. The gel was poured into volumetric flasks, of dimensions comparable to a human head. The gels were irradiated with complex beam arrangements, similar to those used for conformal radiation therapy. Images of the gels were acquired using a Siemens 1.5T imager and a Hahn spin-echo pulse sequence (90°-τ-180°-τ-acquire, for different values of τ). The images were transferred via network to a Macintosh computer for which a data analysis and display program was written. The program calculates R2 maps on the basis of multiple TE images, using a monoexponential nonlinear least-squares fit based on the Levenberg-Marquardt algorithm. The program also creates a dose-to-R2 calibration function by fitting a polynomial to a set of dose and R2 data points, obtained from gels irradiated in test tubes to known doses. This function can then be applied to any other R2 map, so that a dose map can be computed and displayed.

: Through exposure to known doses of radiation, the gel has been shown to respond linearly with dose in the range of 0 to 10 Gy, and its response is independent of the beam energy or modality. Dose distributions have been imaged in orthogonal planes, and can be displayed in a convenient form for comparison with isodose plans. The response of the gel is stable; the gel can be irradiated at any time after its manufacture, and imaging can be conducted any time following a brief interval after irradiation.

: The polymer gel dosimeter has been shown to be a valuable device for displaying three-dimensional dose distributions. The imaged dose distribution can be compared easily with calculated dose distributions, to validate a treatment planning system. In the future, gels may be prepared in anthropomorphic phantoms, to confirm unique patient dose distributions.     

Radioenhancement by cisplatin with accelerated fractionated radiotherapy in a human tumour xenograft

The aim of the present study was to investigate whether cisplatin would enhance the radioresponse of a human tumour xenograft when given in different schedules combined with accelerated fractionated radiation therapy. A human squamous carcinoma of the hypopharynx, FaDu, was grown in the thigh of athymic nude mice. Tumours were exposed to twice-daily 2-Gy fractions, applied 6 h apart over 2 weeks, 5 days a week, alone or combined with cisplatin given at maximally tolerated doses in three different schedules: (1) i.p. as a single bolus (SB) or (2) i.p. as a daily bolus at 30 min before the first daily radiation fraction or (3) s.c. as a continuous infusion through a mini-osmotic pump over 13 days, commencing 24 h prior to the first daily radiation fraction. The end point for the study was tumour growth delay (TGD), calculated as the difference between the delay in regrowth to 200% of the initial tumour size in treated versus control mice. SB cisplatin plus radiation showed only an additive effect on TGD, whereas daily-bolus and continuous-infusion cisplatin demonstrated a greater than additive effect when combined with accelerated fractionated radiation in this human tumour model. Cisplatin appears to be especially beneficial as a radiation enhancer when given throughout the course of radiation. Received: 15 December 1996 / Accepted: 25 March 1997     

Increased risk of salivary gland tumors after low-dose irradiation

Objective: To assess the risk of neoplastic development among persons exposed to scalp irradiation. Study Design: Historical cohort study initially; prospective follow-up subsequently. Method: Two control groups—population and siblings—matched for age, sex, ethnic origin, and year of immigration. Follow-up from time of irradiation (1950s) until the end of 1991. Linkage with nationwide cancer registry. Results: A 4.5–fold incidence of cancer (P < .01) and a 2.6–fold increase of benign tumors were noted. The mean length of latency period until tumor development was 11 years for malignant tumors and 21.5 years for benign. A clear dose response effect for both cancer and benign tumors was demonstrated. Conclusions: The study confirms the role of radiation in salivary gland carcinogenesis. It indicates a need for better awareness, a comprehensive examination, and long-term follow-up of patients who have been subjected to head and neck radiation.     

放、化疗同步与非同步治疗Ⅲ期非小细胞肺癌的对比观察

目的:为比较放、化疗同步治疗与非同步治疗肺癌的临床效果.方法:选择不手术的Ⅲ期非小细胞肺癌(NSCLC)患者81例,随机分为同步治疗组(42例)和非同步组(39例).结果:治疗总有效率同步组66.7%,非同步组61.5%,前者略高于后者,两者比较无显著差异(P>0.05),但达到上述有效率所用的时间前者平均69天,后者为143天,两者比较有非常显著差异(P<0.01).结论:同步组的近期疗效似优于非同步组,且前者治疗周期、住院周期缩短,更有利于患者康复.     

61例喉癌单纯放射治疗临床分析

目的喉癌单纯放疗效果分析。方法６１例喉癌，以６０Ｃｏ外放射治疗，常规照射。结果五年生存率，声门癌６５％，声门上型癌２４．４％。结论推荐剂量，声门癌Ｔ１Ｔ２６０００ｃＧｙ，Ｔ３６８００ｃＧｙ。声门上型癌Ｔ１Ｔ２６０００～６５００ｃＧｙ，Ｔ３７０００ｃＧｙ。     

76例乳腺癌术后放疗

 从1985年1月～1990年1月，我们对76例乳癌术后患者进行了放疗。Ⅱ期54例、Ⅲ期18例、Ⅳ期4例。放疗采用60钴γ线或6mv一x线、10～12mev电子线。照射胸壁、内乳、锁骨上、腋下等区域。放疗剂量45～50Gy/4.5～5周，5年生存率Ⅱ期80.6％（25/31）、Ⅲ期33.3％（3/9）、Ⅳ期25％（1/4）。我们认为放疗对Ⅱ期以上的患者可降低复发率、提高生存率     

Enhancement of Radiation Response by Paclitaxel in Mice According to Different Treatment Schedules

Purpose: The aim of our study was to determine if paclitaxel could be used as a radiosensitizer in vivo.

Materials and methods: Paclitaxel was tested as a single agent and combined with an X-ray treatment. Paclitaxel was administered i.p. in doses from 30 to 120 mg/kg b.w. to (C3D2F1) mice bearing spontaneous mammary carcinoma. Tumor growth delay (TGD) or tumor control dose (TCD₅₀, radiation dose needed to induce local tumor control in 50% of irradiated animals) and moist desquamation dose (MDD₅₀, radiation dose needed to induce serious moist desquamation in 50% of the non-tumor-bearing feet) were the endpoints. DNA flow cytometric analysis was performed.

Results: DNA analysis demonstrated a G2/M block of tumor cells and a depletion of cells in S phase, with a maximum at 24 h from paclitaxel administration. Administering paclitaxel, in graded doses, 15 min before a 10-Gy X-ray treatment resulted in a linear regression line, almost parallel to that with paclitaxel alone, with a growth delay of about 6 days. In contrast, varying the X-ray dose with a constant paclitaxel injection (45 mg/kg b.w.) treatment showed some degree of synergism as the linear regression curves diverged. Interval time and sequence between paclitaxel administration and a 10 Gy X-ray treatment did not influence TGD. Protocols with paclitaxel at 30, 45, or 60 mg/kg were combined with radiation treatments at various doses (from 10 to 65 Gy). Values of TCD50 varied from 50.8 Gy for X-ray alone to 31.8 Gy for paclitaxel 60 mg/kg + X-ray. No differences were observed among MDD of different protocols.

Conclusions: These results suggest that, under some conditions, paclitaxel combined with radiation can show superadditive effects and this result combined with the lack of severe normal tissue damage indicate that a favorable therapeutic gain can be obtained.