蒙脱石散对盐酸左氧氟沙星体外吸附的影响

目的: 探讨蒙脱石散对盐酸左氧氟沙星体外吸附的影响.方法: 采用不同剂量的盐酸左氧氟沙星分别与3 g蒙脱石散混合,加入0.1 mol·L-1盐酸溶液中,在(37±0.5)℃水浴中恒温2 h后过滤,用紫外分光光度法测定盐酸左氧氟沙星的含量变化.结果: 蒙脱石散对盐酸左氧氟沙星的吸附率为(98.37±0.03)%.结论: 蒙脱石散对盐酸左氧氟沙星有极强吸附,因此应避免两种药物同时服用.     

艾拉莫德片溶出度测定方法研究

目的:建立紫外分光光度法测定艾拉莫德片溶出度的方法。方法:以磷酸盐缓冲液(pH 8.0)1000 mL为溶出介质,转速75 r·min-1,紫外分光光度法测定溶出量,检测波长257 nm。结果:在1.04-16.7μg·mL-1范围内呈良好的线性关系,r=0.9999,精密度RSD为0.3％(n=6)。结论:本方法简便、准确,可用于艾拉莫德片剂的溶出度测定。     

Expression of cathepsin D and epidermal growth factor receptor in stage III cervical carcinomas

Cathepsin D and epidermal growth factor receptor (EGFR) antigens are related to tumor invasion, metastasis, progression, and recurrence. To assess the prognostic significance of the expression of these two antigens, biopsy specimens consecutively obtained from 216 patients with stage III cervical carcinomas (191 with squamous cell carcinomas and 25 with adenocarcinomas), who were treated with radiotherapy, were investigated immunohistochemically. The positive rate of cathepsin D expression in squamous cell carcinomas was 74%, significantly higher than the 47% observed in adenocarcinomas ( P  = 0.015). The EGFR positive rate in squamous cell carcinomas was 33%, somewhat higher than the 16% in adenocarcinomas ( P  = 0.088). The chi-square test and Kaplan–Meier method showed no significant relationship between the expression of either cathepsin D or EGFR and the prognosis in these patients. These results indicate that in stage III cervical carcinomas cathepsin D and EGFR expression do not correlate with prognosis.     

UV—微O3法去除饮用水中CCl4的研究

研究了以紫外－微臭氧为主体的光化学激发氧化技术的最佳运行参数，用该工艺处理饮用水中微量有机优先污染物。研究结果表明：紫外－微臭氧工艺对ＣＣｌ４－水中常见有机优先污染物有令人满意的去除效果，经２小时处理后，去除率可达９０％，紫外－微臭氧工艺对饮用水的深度处理能力接近于紫外－臭氧工艺，设备方便，投资少，是一种很有前途的饮用水净化工艺。     

Second cancers after medulloblastoma: population-based results from the United States and Sweden

Medulloblastoma, one of the most common central nervous system(CNS)tumors in children, requires aggressive multimodality therapy including surgery, radiation therapy, and occasionally chemotherapy. Given its intensive treatment regimen and improved survival during the past 20 years, it is likely that a cohort of survivors will result who may incur consequences of therapy, including a second cancer. We used population-based data from the United States and Sweden to estimate risks of second neo plasms in patients with histologically confirmed medulloblastoma (n = 1,262).Overall, there was a 5.4-fold excess of second neoplasms (95 percent confidence interval = 3.3-8.4) based on 20 observed and 3.7 expected cancers. The second cancers occurred eight to 432 months after initial diagnosis(median, 73 months) with significantly elevated ratios for all intervals examined except for less than one year after initial diagnosis. Significantly elevated risks were seen for cancers of the salivary glands, cervix uteri, brain and CNS, thyroid gland, and acute lymphoblastic leukemia. Of the 15second cancers with treatment data, seven occurred in the radiation field or within areas of scatter while two others may have been radiation-related. Although based on small numbers of second cancers, the results suggest that as survival increases, some patients with medulloblastoma will have an increased risk of a second cancer, particularly a radiation-related cancer. Thus, as survival improves, late-occurring consequences of diagnosis and treatment will need to be carefully assessed. Identification of patients hypersensitive to radiation therapy, such as those with Gorlin Syndrome, should also be attempted in order to reduce the sequelae from intensive radiation exposure. This revised version was published online in July 2006 with corrections to the Cover Date.     

Permanent low-activity iodine-125 implants for cerebral metastases

Beginning in 1987, selected patients with metastatic braintumors were treated with permanent implants of low-activityradioactive iodine-125 (¹²⁵I) seeds. These patients underwent craniotomy,gross total resection of the metastatic lesion, andplacement of the seeds. In general, criteria fortreatment included the presence of a recurrent tumorwith a volume too large to permit radiosurgery,and a Karnofsky Performance Score of 70 orhigher. Thirteen patients underwent 14 implant procedures; allreceived external whole-brain radiotherapy. Implant dose ranged from43 Gy to 132 Gy, with a meanof 83 Gy. Survival after implantation ranged from2 weeks to almost 9 years, with amedian of 9 months. Clinical and radiographic localcontrol was obtained in 9 patients. Two patientsdied of acute, postoperative complications within a monthof implantation, so no information regarding tumor controlis available for them. Late complications included abone flap infection in one patient and aCSF leak in another; both were treated withoutfurther sequelae.These results demonstrate that permanent ¹²⁵I implants canresult in good survival and quality of life,and occasionally can yield long-term survival. Potentially, itis a cost-effective treatment in that a separateprocedure for stereotactic implantation or radiosurgery is notneeded, as is the case with the useof temporary high-activity seeds. The permanent implantation itselfadds less than 10 minutes to the craniotomy,and the risk of symptomatic radiation necrosis islow. We recommend consideration of this procedure inpatients harboring large, recurrent metastatic tumors that requirefurther surgery.     

Photoprotective effects of some quinoxaline 1,4-dioxides in hairless mice

2-benzoyl-3-phenylquinoxaline 1,4-dioxide (BPQ) and other substituted quinoxaline 1,4-dioxides (QdO) were tested for their ability to inhibit the stimulations of ornithine decarboxylase (ODC) enzyme activity and DNA synthesis, two biochemical markers linked to skin tumour promotion by ultraviolet B (UVB) radiation. Topical application of BPQ on the dorsal skin of hairless mice was found to inhibit in a dose-dependent manner UVB-induced ODC activity and DNA synthesis. When applied 20 min before UVB radiation, a dose of 17 mg BPQ applied in 0.4 ml of vehicle inhibited UVB-induced ODC activity and DNA synthesis by 95% and 85%, respectively. This inhibitory effect is dependent on the time of administration of BPQ relative to UVB radiation, with a generally greater inhibition observed when this compound is applied before rather than after UVB treatment. The inhibitory abilities of the other QdO on the ODC and DNA responses induced by UVB radiation greatly varied and appear to be dependent on the structure of the compounds and their metabolic activation in the skin following irradiation. The remarkable effectiveness of BPQ against the ODC and DNA markers of UVB promotion is also observed following multiple applications of this agent. These results suggest that QdO, in particular BPQ and certain derivatives of it, may be useful in protecting the skin against UVB-induced skin damage.     

The results of radiotherapy for brainstem tumors

Objective: This analysis was performed to examine the outcome of adult and pediatric patients with brainstem tumors. Methods and materials: Forty patients with brainstem glioma were evaluated retrospectively. Included were 24 females and 16 males ranging in age from 3 to 81 years (median, 29.5 years). These patients were treated with various combinations of surgery, chemotherapy, and ratiotherapy (RT). The length of follow-up in survivors ranged from 0.6 to 20 years (median: 3.2 years, mean: 6 years). Survival rates were calculated with the Kaplan Meier method and differences between survival curves were calculated using the log-rank test. Results: The overall 2 and 5-year survival rates were 44% and 34%, respectively. The median survival time was 19 months. The 5-year survival rate was 54% for patients with tumors outside the pons compared to 21% for those with tumors involving the pons (p=0.04). The 5-year survival rate was 59% for patients with exophytic tumors as compared to 23% for those with intrinsic tumors (p=0.05). Patients undergoing subtotal resection had a 5-year survival rate of 53% compared to 28% for those having only a biopsy or no surgical intervention (p=0.04). None of the other potential prognostic or treatment related factors evaluated [patient age, tumor grade, tumor histology, radiotherapy parameters (including BID fractionation, 3-D treatment planning, or the use of doses > 55 Gy), or the administration of adjuvant chemotherapy] evaluated were associated with patient survival. Conclusions: Brainstem gliomas generally occur in younger individuals. The survival rates were better for patients with exophytic tumors, those involving sites other than the pons, and tumors amenable to subtotal resection. Improvements in the outcome of patients with brainstem gliomas will require new therapeutic approaches.     

Mechanism of action of lonidamine in the 9L brain tumor model involves inhibition of lactate efflux and intracellular acidification

Malignant gliomas have been associated with a high rate of glycolytic activity which is believed necessary to sustain cellular function and integrity. Since lonidamine (LND) is believed to reduce tumor glucose utilization by inhibition of the mitochondrially-bound glycolytic enzyme hexokinase (HK), ³¹P magnetic resonance spectroscopy (MRS) was used to noninvasively follow the effects of LND on both tumor pH and the high-energy phosphate metabolites; ATP, phosphocreatine (PCr) and inorganic phosphate (P_i) in subcutaneous rat 9L gliosarcomas. ³¹P tumor spectra acquired in 5 min intervals pre- and post LND administration of 50 and 100 mg/kg, i.p. revealed an acidotic pH shift of – 0.25 and – 0.45 pH units, respectively within 30 min post administration. The ATP/P_i ratio of 9L tumors decreased to 40% of control and P_i levels increased to 280% of control over a 3 hr period. LND exerted no effect on tumor blood flow and mean arterial blood pressure. Brain and muscle metabolite levels and pH were also unaffected by LND. In vitro measurements of cultured 9L tumor cell intra- and extracellular lactate, pentose phosphate pathway (PPP) and hexokinase (HK) activities suggest that the mode of action of LND involves inhibition of lactate efflux and intracellular acidification. The selective reduction of tumor energy metabolites and pH by LND may be exploitable for sensitizing gliomas to radiation, chemotherapy or hyperthermia.