石杉碱甲类似物的研究II.N-甲基吡啶酮石杉碱甲类似物的合成

石杉碱甲(1)是从中草药石杉属植物千层塔(Lycopodium serratum Thunb.)中分得的一种高效可逆的乙酰胆碱酯酶抑制剂,临床试验证实它对早老性痴呆症有显著疗效。本文报道N-甲基吡啶酮石杉碱甲类似物2和3的合成。2-甲氧基-5-甲氧羰基-11-亚甲基-5,9-甲撑环辛-7-烯并吡啶(9)在乙腈中用三甲基氯硅烷和碘化钠选择性脱保护以定量的产率得吡啶酮10,再用甲醇钠和碘甲烷甲基化得N-甲基吡啶酮11,11经碱性水解,Curtius重排和氨基的脱保护得N-甲基吡啶酮石杉碱甲类似物2。通过类似的途径从中间体2-甲氧基-5-甲氧羰基-7-甲基-11-酮-5,9-甲撑环辛-7-烯并吡啶(14)合成了类似物3。类似物2和3的乙酰胆碱酯酶抑制活性均低于天然石杉碱甲。     

石杉碱甲类似物的研究Ⅲ．N－甲基吡啶酮石杉碱甲类似物的合成

石杉碱甲（１）是从中草药石杉属植物千层塔（ＬｙｃｏｐｏｄｉｕｍｓｅｒｒａｔｕｍＴｈｕｎｂ．）中分得的一种高效可逆的乙酰胆碱酯酶抑制剂，临床试验证实它对早老性痴呆症有显著疗效。本文报道Ｎ－甲基吡啶酮石杉碱甲类似物２和３的合成。２－甲氧基－５－甲氧羰基－１１－亚甲基－５，９－甲撑环辛－７－烯并吡啶（９）在乙腈中用三甲基氯硅烷和碘化钠选择性脱保护以定量的产率得吡啶酮１０，再用甲醇钠和碘甲烷甲基化得Ｎ－甲基吡啶酮１１，１１经碱性水解，Ｃｕｒｔｉｕｓ重排和氨基的脱保护得Ｎ－甲基吡啶酮石杉碱甲类似物２。通过类似的途径从中间体２－甲氧基－５－甲氧羰基－７－甲基－１１－酮－５，９－甲撑环辛－７－烯并吡啶（１４）合成了类似物３。类似物２和３的乙酰胆碱酯酶抑制活性均低于天然石杉碱甲。     

Individual,Social, and Environmental Factors Associated with Initiating Methamphetamine Injection: Implications for Drug Use and HIV Prevention Strategies

The purpose of this study was to determine the incidence and predictors of initiating methamphetamine injection among a cohort of injection drug users (IDU). We conducted a longitudinal analysis of IDU participating in a prospective study between June 2001 and May 2008 in Vancouver, Canada. IDU who had never reported injecting methamphetamine at the study’s commencement were eligible. We used Cox proportional hazards models to identify the predictors of initiating methamphetamine injection. The outcome was time to first report of methamphetamine injection. Time-updated independent variables of interest included sociodemographic characteristics, drug use patterns, and social, economic and environmental factors. Of 1317 eligible individuals, the median age was 39.9 and 522 (39.6%) were female. At the study’s conclusion, 200 (15.2%) participants had initiated injecting methamphetamine (incidence density: 4.3 per 100 person-years). In multivariate analysis, age (adjusted hazard ratio [aHR]: 0.96 per year older, 95%CI: 0.95–0.98), female sex (aHR: 0.58, 95%CI: 0.41–0.82), sexual abuse (aHR: 1.63, 95%CI: 1.18–2.23), using drugs in Vancouver’s drug scene epicentre (aHR: 2.15 95%CI: 1.49–3.10), homelessness (aHR: 1.43, 95%CI: 1.01–2.04), non-injection crack cocaine use (aHR: 2.06, 95%CI: 1.36–3.14), and non-injection methamphetamine use (aHR: 3.69, 95%CI: 2.03–6.70) were associated with initiating methamphetamine injection. We observed a high incidence of methamphetamine initiation, particularly among young IDU, stimulant users, homeless individuals, and those involved in the city’s open drug scene. These data should be useful for the development of a broad set of interventions aimed at reducing initiation into methamphetamine injection among IDU.     

GSTP1 and ABCB1 Polymorphisms Predicting Toxicities and Clinical Management on Carboplatin and Paclitaxel‐Based Chemotherapy in Ovarian Cancer

Variation in drug disposition genes might contribute to susceptibility to toxicities and interindividual differences in clinical management on chemotherapy for epithelial ovarian cancer (EOC). This study was designed to explore the association of GST and ABCB1 genetic variation with hematologic and neurologic toxicity, changes in chemotherapy, and disease prognosis in Brazilian women with EOC. A total of 112 women with a confirmed histological diagnosis of EOC treated with carboplatin/paclitaxel were enrolled (2014–2019). The samples were analyzed by multiplex polymerase chain reaction (PCR) for the deletion of GSTM1 and GSTT1 genes. GSTP1 (c.313A>G/rs1695) and ABCB1 (c.1236C>T/rs1128503; c.3435C>T/rs1045642; c.2677G>T>A/rs2032582) single nucleotide polymorphisms (SNPs) were detected by real‐time PCR. Subjects with the GSTP1 c.313A>G had reduced risk of anemia (odds ratio (OR): 0.17, 95% confidence interval (CI): 0.04–0.69, P = 0.01, dominant model) and for thrombocytopenia (OR: 0.27, 95% CI: 0.12–0.64, P < 0.01; OR 0.18, 95% CI 0.03–0.85, P = 0.03, either dominant or recessive model), respectively. The GSTP1 c.313A>G AG genotype was associated with a lower risk of dose delay (OR: 0.35, 95% CI: 0.13–0.90, P = 0.03). The ABCB1 c.1236C>T was associated with increased risk of thrombocytopenia (OR: 0.15, 95% CI: 0.03–0.82, P = 0.03), whereas ABCB1 c.3435C>T had increased risk of grade 2 and 3 neurotoxicity (OR: 3.61, 95% CI: 1.08–121.01, P = 0.03) in recessive model (CC + CT vs. TT). This study suggests that GSTP1 c.313A>G, ABCB1 c.1236C>T, and c.3435C>T SNP detection is a potential predictor of hematological toxicity and neurotoxicity and could help predict the clinical management of women with EOC.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Variation in drug disposition genes encoding drug‐metabolizing enzymes and transporters might contribute to susceptibility to toxicities and interindividual differences in clinical management such as the need to delay, reduce, or discontinue treatment.

• WHAT QUESTION DID THIS STUDY ADDRESS?

We studied the association of GST and ABCB1 genetic variation with hematologic and neurologic toxicity, clinical management, and disease prognosis in Brazilian women with epithelial ovarian carcinoma (EOC) who undergo carboplatin and paclitaxel‐based chemotherapy.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

GSTP1 c.313A>G is a potential predictor of anemia and thrombocytopenia and associated with a lower risk of dose delay during chemotherapy. In addition, ABCB1 c.1236C>T and c.3435C>T is associated with a higher risk of thrombocytopenia and neurotoxicity.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

The polymorphism detection could be a strategy to careful monitoring of patients at increased risk of toxicity and appropriate supportive therapy could decrease the need for changes in treatment, thus improving the likelihood of a beneficial treatment response in women with EOC.

Epithelial ovarian cancer (EOC) is the most common cause of gynecological cancer death, largely due to the advanced stage of the disease at the time of diagnosis. ¹ Standard first‐line treatment is cytoreductive surgery and subsequent chemotherapy using a combination of carboplatin and paclitaxel or neoadjuvant chemotherapy and residual tumor resection. ² Despite a high response rate to chemotherapy, ~ 70% of the women have a relapse within the subsequent 3 years. ³ Platinum and taxane‐based chemotherapy are often associated with severe hematological toxicities, such as anemia, neutropenia, leukopenia, and thrombocytopenia. ⁴ In addition, neuropathy is a dose‐limiting side effect of paclitaxel. ⁵ , ⁶ Interindividual differences in carboplatin and paclitaxel toxicity may be associated with polymorphisms in genes encoding drug‐metabolizing enzymes and transporters, including GSTs and ATP‐binding cassette (ABC) efflux transporters like ABCB1. ⁴ , ⁷ , ⁸ , ⁹ The GSTs are a family of phase II enzymes involved in detoxification of xenobiotics by conjugation reactions between glutathione and endogenous and exogenous electrophilic compounds, such as chemotherapeutic drugs, including the platinum agents. The GST family consists of several gene subfamilies of which GSTM1, GSTT1, and GSTP1 are the most relevant for drug metabolism. ¹⁰ , ¹¹ Functional GSTM1 and GSTT1 enzymes are directly related with the presence of the intact genes, because the absence of activity is the result of a 15 kb and 54 kb deletions that span the entire GSTM1 and GSTT1 genes (GSTM1‐null and GSTT1‐null genotypes), respectively. Consequently, individuals homozygous for the GSTM1 or GSTT1‐null allele have a complete absence of GSTM1 and GSTT1 activity, whereas individuals with two copies of the GSTM1 or GSTT1 genes have reference protein levels. ¹² , ¹³ There is some evidence that these deletion genotypes may play a role in toxicity, response to treatment, and survival in some cancers, ¹⁴ , ¹⁵ , ¹⁶ including cancer of the ovary. ⁸ In contrast to the commonly studied GSTM1 and GSTT1 genotypes, the GSTP1 c.313A>G (rs1695) is an exonic single nucleotide polymorphism (SNP) that causes an amino acid substitution and results in an isoleucine to valine (Ile > Val) change at codon 105 of the enzyme. The highest level of GSTP1 activity is seen in individuals with the AA genotype (Ile/Ile) and is associated with increased toxicity in different carcinomas, but there are discordant results regarding the effect of GSTP1 c.313A>G on treatment outcomes. ⁹ , ¹⁷ , ¹⁸ , ¹⁹ , ²⁰ Polymorphisms in ABCB1 or multidrug resistance 1 may affect the function of P‐glycoprotein, a critical transporter for efflux of paclitaxel from cells. ²¹ , ²² Three SNPs in the coding region of ABCB1 (c.1236C>T, rs1128503; c.3435C>T, rs1045642; and c.2677G>T>A, rs2032582) have been extensively studied. ²³ , ²⁴ These common ABCB1 SNPs have been associated with toxicity during carboplatin and paclitaxel‐based chemotherapy, including increased risk of anemia in carriers of the c.1236C>T SNP, a more pronounced neutrophil decrease in patients carrying the c.3435C>T and c.2677G>T>A SNPs and increased risk of peripheral neuropathy associated with the c.3435C>T SNP. ¹⁸ , ²⁵ , ²⁶ Similar to studies of GST polymorphisms, the associations of ABCB1 genetic variation with treatment outcomes is inconsistent across studies. ²⁷ , ²⁸ Patients developing severe toxicities often require dose reduction, dose delay, or treatment interruption that require clinical interventions and may affect the disease prognosis. ⁴ However, no study has been found so far focus on regarding the utility of polymorphisms in the management of chemotherapy and toxicities for ovarian cancer. The current study was designed to examine the association of GST and ABCB1 genetic variants with hematologic and neurologic toxicities, clinical management on chemotherapy, and disease prognosis in Brazilian women with EOC.     

肿瘤干细胞的研究与进展

目的:作为"种子细胞"的肿瘤干细胞对研究肿瘤发生及其临床治疗具有重要意义。总结近年来肿瘤干细胞的研究进展,对肿瘤干细胞的概念、特性及应用进行综述。资料来源:应用计算机检索Medline数据库1980-01/2006-12期间的相关文章,检索词为"cancer stem cells",限定文章语言种类为English。资料选择:对资料进行初审,并查看每篇文献后的引文。纳入标准:肿瘤干细胞的研究进展及临床价值。排除标准:重复研究。资料提炼:共收集到106篇相关文献,30篇文献符合纳入标准,排除的76篇文献为内容陈旧或重复。符合纳入标准的30篇文献中,分别涉及肿瘤干细胞的定义及来源、研究进展、临床治疗价值等内容。资料综合:肿瘤干细胞具有分裂增殖、自我更新以及分化成其他细胞的能力,目前已证实其存在于白血病、乳腺癌、脑癌、前列腺肿瘤等肿瘤组织中。目前的抗肿瘤治疗方法主要针对的是大多数已经分化的肿瘤细胞,而不能影响到肿瘤干细胞,即治标不治本。肿瘤的复发、转移以及耐药等特征都很可能与肿瘤干细胞有关,因此肿瘤治疗的关键应是针对肿瘤干细胞进行灭杀,又要保护正常干细胞,但此两种细胞表型极为相似,故应找到更为特异的靶点。结论:肿瘤干细胞不仅已经从血液系统的恶性肿瘤中成功分离出来,在大量实体瘤中也证实了肿瘤干细胞的存在,其耐药机制之一是表达一种或多种药物运载蛋白,对于肿瘤的发生及治疗提供了更多的思路和方向。     

CONGENITAL DISLOCATION OF THE KNEE AS A CONSEQUENCE OF PERSISTENT AMNIOTIC FLUID LEAKAGE

SUMMARY A case congenital dislocation of both knees and dislocation of the left hip in an infant whose mother had a chronic amniotic fluid leakage after mid-trimester amniocentesis.