Potent, orally active heterocycle-based combretastatin A-4 analogues: synthesis, structure-activity relationship, pharmacokinetics, and in vivo antitumor activity evaluation

The synthesis and structure-activity relationship study of a series of compounds with heterocycles in place of the cis double bond in combretastatin A-4 (CA-4) are described. Substituted tosylmethyl isocyanides were found to be the key intermediates in construction of the heterocycles. Cytotoxicities of the heterocycle-based CA-4 analogues were evaluated against NCI-H460 and HCT-15 cancer cell lines. 3-Amino-4-methoxyphenyl and N-methyl-indol-5-yl were the best replacements for the 3-hydroxy-4-methoxyphenyl in CA-4. 4,5-Disubstituted imidazole was found to be the best for the replacement of the cis double bond in CA-4. Medicinal chemistry efforts led to the discovery of compounds 24h and 25f that were found to be 32 and 82% bioavailable, respectively, in rat. Evaluation of 24h and 25f against murine M5076 reticulum sarcoma in mice revealed that both compounds were orally efficacious with an increase in life span of 38.5 and 40.5%, respectively.     

Healing of root resorption: a case report

External resorption is sequelae of necrotic periodontal membrane over a large area of root following an injury to the tooth. This usually occurs after severe dental injuries such as intrusion, severe luxations or exarticulation injuries complicated by a prolonged extra oral period. This case report presents a clinical and radiographic follow up (13 months) of treatment of inflammatory external root resorption on maxillary central incisor using Vitapex. Gradual healing of resorption was observed radiographically with no tenderness or pathological mobility.     

Epidermal growth factor improves nutritional outcome in a rat model of short bowel syndrome

Background/Purpose: This study investigates the effect of epidermal growth factor (EGF) on nutrient absorption in a rat model of short bowel syndrome (SBS). Methods: Male juvenile rats underwent either transection (Sham) or ileocecal resection leaving a 20-cm jejunal remnant. Animals underwent follow-up for 10 days, and resected animals were treated with placebo or recombinant human EGF (1-53). Animals were pair fed; in vivo nutrient absorption, intestinal permeability, morphology, and total intestinal DNA and protein content were measured. Results: Resected EGF-treated animals lost significantly less weight than those in the placebo group ([minus ]4.2 [plusmn] 3 v [minus ]13.7 [plusmn] 6.9%), absorbed significantly more 3-0 methylglucose (76.8 [plusmn] 6.6 v 64.9 [plusmn] 10.1%), and had reduced permeability (lactulose/mannitol ratio, 0.35 [plusmn] 0.19 v 0.60 [plusmn] 0.20; P [lt ] .05 for all comparisons). Conclusions: These findings show that treatment of short bowel syndrome animals with EGF reduced weight loss and improved carbohydrate absorption and intestinal permeability. These findings suggest that enteral EGF may be a useful therapy for short bowel syndrome; further studies are indicated.     

Gene-viral vectors: a promising way to target tumor cells and express antican cer genes simultaneously

目的：研究一种结合肿瘤基因治疗与美丽治疗优势的新型肿瘤治疗载体系统,即基因-病毒载体系统。方法：利用病毒重组技术将抗癌基因插入肿瘤细胞特异性的增殖病毒基因组中,通过细胞病理作用、荧光显微镜、免疫酶链技术及电镜等技术分别观察病毒的杀伤效应、报告基因绿色荧光蛋白、抗癌基因小鼠白细胞介素12表达量及病毒复制情况。结果：构建了一种新型基因-病毒载体系统,该载体系统腺病毒E1b-55kDa蛋白缺失,保留了腺病毒E1a蛋白。该载体系统具有肿瘤增殖病毒ONYX-015相似功能,即它可在肿瘤细胞内复制及增殖,而在正常细胞内不能复制及增殖,从而特异性杀灭肿瘤细胞。它还具有更大的优势,即该载体系统可携带各种抗癌基因以进一步提高抗肿瘤的疗效。应用该载体系统携带该报告基因绿色荧光蛋白可使绿色荧光蛋白在肿瘤细胞内高效表达,其表达量明显高于传统基因治疗的腺病毒载体系,而在正常细胞内低表达,与传统腺病毒载体系统相似或更低。应用该载体系统携带抗癌基因小鼠白细胞介素12,也产生类似结果,并在电镜中证实该载体系统携带抗癌基因小鼠白细胞介素12可在肿瘤细胞株中复制及增殖。结论：基因-病毒载体是将抗癌基因插入肿瘤增殖病毒基因组,通过肿瘤增殖病毒在肿瘤细胞内特异性复制及增殖,从而数百倍乃至上万倍提高抗癌基因的表达量。它充分利用了肿瘤基因治疗与病毒治疗优势,进一步提高抗肿瘤的疗效,克服了传统基因治疗转染率低、表达量少及靶向性弱等缺点及病毒治疗的杀伤力低的缺点。它将成为肿瘤治疗最有希望的治疗方案之一。     

Peripheral gamma delta T-cell deficit in nasopharyngeal carcinoma

Previous studies identified CD56(+) and CD56(-) subsets of peripheral gamma delta T cells from healthy donors. Both subsets responded to stimulation by a myeloma cell line, XG-7 and undergo vigorous ex vivo expansion in the presence of exogenous IL-2. They are cytotoxic for different tumor targets including nasopharyngeal carcinoma, but they differ from one another in that the CD56(-) subset has an additional growth requirement for IL-7 and exhibited greater cytotoxicity against nasopharyngeal carcinoma (NPC) targets. These immune cells were further shown to retard tumor growth in a nude mice NPC model. To assess if these immune cells might contribute to host defense against NPC, we compared gamma delta T-cell status of NPC patients with healthy donors and survivors who had been in clinical remission of the cancer. It was found that peripheral gamma delta T cells of patients were impaired in their response to the stimulatory effects of XG-7 and exhibited weak or essentially no cytotoxicity for the NPC targets. The deficits were present in early and advanced stages of the cancer but were restored among survivors after successful treatment of the cancer. These findings support a role for peripheral gamma delta T cells in host defense against NPC. It was noted that these immune cells comprise less than 5% of peripheral blood monocytic cells and hence it was not surprising that this component of host defense was breached early in the development of the cancer.     

Factors affecting risk of symptomatic temporal lobe necrosis: significance of fractional dose and treatment time

PURPOSE: To study the factors affecting the risk of symptomatic temporal lobe necrosis after different fractionation schedules. METHODS AND MATERIALS: One thousand thirty-two patients with T1-2 nasopharyngeal carcinoma treated with radical radiotherapy in Hong Kong during 1990-1995 were studied. They were treated at four different centers with similar techniques but different fractionation schedules: 984 patients were given 1 fraction daily throughout (q.d.), and 48 patients were irradiated twice daily (b.i.d.) for part of the course. The median total dose was 62.5 Gy (range 50.4-71.2), dose per fraction was 2.5 Gy (range 1.6-4.2), and overall treatment time (OTT) was 44 days (range 29-70). In addition, 500 patients received supplementary doses for parapharyngeal extension, 113 received booster doses by brachytherapy, and 114 received sequential chemotherapy using cisplatin-based regimes. RESULTS: Altogether, 24 patients developed symptomatic temporal lobe necrosis: 18 from the q.d. group and 6 from the b.i.d. group. The 5-year actuarial incidence ranged from 0% (after 66 Gy in 33 fractions within 44 days) to 14% (after 71.2 Gy in 40 fractions within 35 days). Multivariate analyses showed that the risk was significantly affected by the fractional effect of the product of total dose and dose per fraction (hazard ratio [HR] = 1.04, 95% confidence interval [CI] 1.02-1.05), OTT (HR 0.88, 95% CI 0.80-0.97), and b.i.d. scheduling (HR 13, 95% CI 3-54). Repeating the analyses for patients treated with the q.d. schedules confirmed the independent significance of OTT in addition to the product of total dose and dose per fraction. CONCLUSION: The tentative results suggest that in addition to fractional dose, the OTT also had significant impact on the risk of temporal lobe necrosis, and b.i.d. scheduling increased the hazard further.     

Concomitant chemoirradiation for stage III-IV nasopharyngeal carcinoma in Chinese patients: results of a matched cohort analysis

PURPOSE: To evaluate the toxicity and efficacy of concomitant chemoirradiation (CRT) followed by adjuvant chemotherapy compared with radiotherapy (RT) alone in Chinese patients with locoregionally advanced nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Between March 1997 and September 2000, 47 Chinese patients with Stage III (n = 9, 19%) and IV (n = 38, 81%) NPC were treated with by CRT using cisplatin 100 mg/m(2) on Days 1, 22, and 43 of RT, plus adjuvant chemotherapy using cisplatin 80 mg/m(2) for 1 day and 5-fluorouracil 1 g/m(2) for 4 days on Days 71, 99, and 127. These patients were then compared with a cohort of 47 patients treated between 1990 and 1993 with RT alone, who were matched with respect to T stage, N stage, nodal bilaterality, nodal level, and nodal size. The RT techniques were similar in the two groups but different dose and fractionation schemes were used. The median biologic equivalent dose to 2 Gy per fraction delivered to the nasopharynx was 68 Gy in the CRT group and 65.3 Gy in the RT-alone group. RESULTS: The compliance rates were 62% for concomitant chemotherapy and 40% for adjuvant chemotherapy. No treatment-related deaths occurred. At the end of treatment, 96% of the CRT group and 79% of the RT-alone group achieved a complete response (p = 0.013). With a median follow-up of 26 months, the 3-year relapse-free survival, disease-specific survival, overall survival, local relapse-free survival, nodal relapse-free survival, and distant metastasis-free survival rate for the CRT group and the RT-alone group was 62% vs. 44% (p = 0.048), 67% vs. 71% (p = 0.88), 65% vs. 69% (p = 0.93), 87% vs. 75% (p = 0.059), 95% vs. 80% (p = 0.026), and 75% vs. 70% (p = 0.84), respectively. CONCLUSION: Our experience indicates that concomitant CRT improves locoregional control in Chinese patients with locoregionally advanced NPC, but our analyses failed to detect any impact on distant failure and survival. The failure to reduce distant metastasis and improve survival may have related in part to the more advanced disease stage in our patients and the relatively low compliance rate of adjuvant chemotherapy. Our findings suggest caution should be exercised in extrapolating the findings of the Intergroup Study 0099 to Chinese patients, and confirmatory results from prospective randomized studies in the endemic population are needed.     

Is waist circumference a useful measure in predicting health outcomes in the elderly?

OBJECTIVE: To examine the effect of age on the relationship between body mass index (BMI) and waist circumference (WC), and the usefulness of BMI, WC and waist-hip ratio (WHR) in predicting mortality and cardiovascular risk in the elderly population. DESIGN: Longitudinal observational study of 36 months duration. SUBJECTS AND METHOD: A stratified random sample of 2,032 Chinese subjects (990 male, 1,033 female) mean age (s.d.) 80.1 (7.5), interviewed and examined at baseline and after 36 months. Deaths and presence of diabetes mellitus and hypertension were documented. A younger data set of 1,010 subjects (500 male, 510 female), mean age (s.d.) 45.5 (11.6), was used for comparison of the BMI-WC relationship between younger and older subjects. In predicting outcomes using different values of BMI, WC and WHR, receiver operating characteristic curve analysis was used to derive cut-off values with optimal sensitivity and specificity, and the likelihood ratios for mortality, diabetes and hypertension for different anthropometric values were plotted. RESULTS: The waist circumference values corresponding to BMI values of 25 and 30 kg/m(2) were higher in elderly (92 and 103 cm for men; 88 and 99 cm for women) compared with younger subjects (85 and 97 cm for men; 78 and 88 cm for women). BMI and WC are inversely associated with mortality, in both men and women, positively associated with diabetes in men but not in women. WC was positively associated with hypertension in men and women. WHR was not associated with any outcome measures. The anthropometric measurement at the point of intersection of the likelihood curves for mortality and diabetes may be considered the optimum value, being BMI=21 kg/m(2) for men and 25 kg/m(2) for women, WC between 80 and 85 cm, and WHR 0.88-0.90. CONCLUSION: Waist measurement values for predicting health outcomes in elderly people aged 70 y and over are different compared with younger subjects, and have similar predictive accuracy compared with body mass index. Waist-hip ratio is not a useful predictor.     

乙肝病毒表面抗原大蛋白与HBV复制状况的相关分析

目的:通过检测慢性乙肝(chronic hepatitis B,CHB)患者血清中乙肝病毒表面抗原大蛋白(large surface protein,LHBs)、HBV DNA以及乙肝病毒标志物(HBsAg/HBsAb、HBeAg/HBeAb、HBcAb,简称HBV-M)模式测定,探讨LHBs与HBV DNA及HBV-M模式间的关系,研究LHBs反应HBV复制情况的可靠性,揭示HBeAg阴性乙肝患者检测LHBs的临床意义。方法:采用酶联免疫吸附试验(ELISA)对LHBs和乙型肝炎抗原抗体五项进行检测;采用荧光定量PCR方法对HBV DNA进行检测。结果:534份乙肝患者HBV DNA、LHBs、乙型肝炎抗原抗体五项的检测结果显示:LHBs阳性与HBeAg阴性间测定结果差异有统计学意义(P=0.001,χ2=10.847),不同HBV-M模式的HBV DNA与LHBs检出结果差异有统计学意义(P<0.001,χ2=37.8761)。结论:LHBs是从蛋白水平反应HBV感染者体内病毒复制程度的可靠指标,血清中的LHBs与HBVDNA具有较好的相关性,尤其是HBeAg阴性患者LHBs检测可作为体内病毒复制及预后判断的良好血清学指标。