PAHs and PM2.5 emissions and female breast cancer incidence in metro Atlanta and rural Georgia

Environmental chemical exposure could be an important etiologic factor for geographic differences in breast cancer incidence. In this study, we examined emissions of polycyclic aromatic hydrocarbons (PAHs) and PM_2.5 in relation to breast cancer incidence in metro Atlanta and rural Georgia by analyzing data from the Surveillance, Epidemiology, and End Results Program and the Environmental Protection Agency. The results showed that metro Atlanta had a significantly higher age-adjusted annual incidence rate of female breast cancer than rural Georgia (132.6 vs. 113.7 per 100,000) for 1992–2011. Emissions of both PAHs [adjusted β = 0.568 (95 % CI: 0.209, 0.927); p = 0.004] and PM_2.5 [adjusted β = 2.964 (95 % CI: 0.468, 5.459); p = 0.023] were significantly associated with breast cancer incidence in metro Atlanta area. This study suggests that ambient air pollution, especially PAHs and PM_2.5, could have a significant impact on the increased incidence of female breast cancer in urban areas.     

Determination of polycyclic aromatic hydrocarbons (PAHs) in cosmetic products by gas chromatography-tandem mass spectrometry

A gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) method is developed to determine 18 representative polycyclic aromatic hydrocarbons (PAHs) in cosmetics, including Benzo[a]pyrene (BaP) and others. The method offers high sensitivity and selectivity under selected reaction monitoring (SRM) mode to satisfy the requirements of both quantitation and qualitation. The extraction solvent system used in this study is acetone/hexane 1:1 (v/v) and other purification procedure is unnecessary. The linearities of 18 PAHs are validated in different concentration in the range of 0.25–20 ng/mL individually with coefficient correlation (r) higher than 0.996. The recoveries for spiking 3 different concentrations are from 87.40% to 120.44% for 18 PAHs and the coefficient of variation (CV) are below 12.32%. Limit of quantification (LOQ) of 18 PAHs is in the range of 0.05–0.2 mg/kg. A matrix enhancement effect is observed and can be compensated with deuterated internal standard. The method has been successfully applied to 73 samples, over 40 of them are lipsticks. The results show none of the samples detect Benzo[a]pyrene (BaP) and Dibenzo[a,h]anthracene (DBA), both are classified as the most carcinogenic. 8 PAHs are detected and the average value between 0.08 and 0.27 mg/kg. This study offers a sensitive and simple method to analyze 18 representative PAHs successfully and can be applied to cosmetic products and raw materials.     

Host–microbiome interactions: the aryl hydrocarbon receptor as a critical node in tryptophan metabolites to brain signaling

ABSTRACT

Tryptophan (Trp) is not only a nutrient enhancer but also has systemic effects. Trp metabolites signaling through the well-known aryl hydrocarbon receptor (AhR) constitute the interface of microbiome-gut-brain axis. However, the pathway through which Trp metabolites affect central nervous system (CNS) function have not been fully elucidated. AhR participates in a broad variety of physiological and pathological processes that also highly relevant to intestinal homeostasis and CNS diseases. Via the AhR-dependent mechanism, Trp metabolites connect bidirectional signaling between the gut microbiome and the brain, mediated via immune, metabolic, and neural (vagal) signaling mechanisms, with downstream effects on behavior and CNS function. These findings shed light on the complex Trp regulation of microbiome-gut-brain axis and add another facet to our understanding that dietary Trp is expected to be a promising noninvasive approach for alleviating systemic diseases.     

Blunted renal dopaminergic system activity in puromycin aminonucleoside-induced nephrotic syndrome.

BACKGROUND: A primary tubular sodium handling abnormality has been implicated in the edema formation of nephrotic syndrome. Dopamine synthesized by renal proximal tubules behaves as an endogenous natriuretic hormone by activating D(1)-like receptors as a paracrine/autocrine substance. METHODS: We examined the time courses of the urinary excretion of sodium, protein and dopamine in puromycin aminonucleoside (PAN)-treated and control rats. The rats were sacrificed during greatest sodium retention (day 7) as well as during negative sodium balance (day 14) for the evaluation of renal aromatic l-amino acid decarboxylase (AADC) activity, the enzyme responsible for the synthesis of renal dopamine. Also, the influence of volume expansion (VE) and the effects of the D(1)-like agonist fenoldopam (10 microg/kg bw/min) on natriuresis and on proximal tubular Na(+),K(+)-ATPase activity were examined on day 7. RESULTS: The daily urinary excretion of dopamine was decreased in PAN-treated rats, from day 5 and beyond. This was accompanied by a marked decrease in the renal AADC activity, on days 7 and 14. During VE, the fenoldopam-induced decrease in proximal tubular Na(+),K(+)-ATPase activity was more pronounced in PAN-treated rats than in controls. However, the urinary sodium excretion during fenoldopam infusion was markedly increased in control rats but was not altered in PAN-treated animals. CONCLUSION: PAN nephrosis is associated with a blunted renal dopaminergic system activity which may contribute to enhance the proximal tubular Na(+),K(+)-ATPase activity. However, the lack of renal dopamine appears not to be related with the overall renal sodium retention in a state of proteinuria.     

煤焦沥青诱发大鼠肺癌的实验研究——Ⅱ.形态学观察

本文对煤焦沥青诱发大鼠肺癌过程中的病理形态学所见作了报道。整个过程可以分为三个阶段:1.异物反应阶段;2.异常增生和鳞状化生阶段;3.癌肿发生发展阶段。文中对每一个阶段的病理组织学改变做了详细描述。煤焦沥青诱发的大鼠肺癌的特征如下:1.癌肿全都发生在肺的周边部位;2.绝大多数癌肿的组织类型都是高分化鳞状细胞癌;3.多发性,数个至数十个大小不等的肿块布满全肺;4.癌变各个不同阶段的改变可在同一肺脏中出现;5.转移癌较少见。     

裂解汽油在ZSM-5沸石上的芳构化

采用连续流动反应装置,考察了裂解汽油在HZSM-5与金属元素改性的HZSM-5上的芳构化反应,发现锌改性后提高了液体产物中芳烃的收率。为了克服裂解汽油中含硫含焦杂质的影响,提出了获取芳烃的有效工艺:蒸馏除焦-加氢预脱硫-氢气氛下芳构化反应-冷凝产物。用氨吸附的程序升温脱附法,将催化剂的酸性质与其催化芳构化作用进行关联,认为Zn改性后的HZSM-5催化剂具有较温和的酸中心,可能是其芳构化高活性与高选择性的原因。     

消化系疾患的血清氨基酸检测

本文报告50名正常人及73例消化系疾病患者血清游离氨基酸检测结果。使用氨基酸自动分析仪,对血中40余种氨基酸组分进行定性定量测定。肝硬化病人芳香氨基酸显著升高,支/芳分子比值明显低于正常值(P<0.01),甲硫氨酸、色氨酸均升高.肝脓疡.消化道肿瘤患者也有此种变化(P<0.05)。统计21种组分中,各病理组有10多种组分有非常显著差异(P<0.01)。结果提示:血液氨基酸测定可为某些消化系疾患,尤其是肝病的诊治提供较好指标。本文改进自动分析条件,节省时间。节约试剂。     

Cancer risk due to occupational exposure to polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) demonstrate carcinogenic activity in animal models. Although some epidemiologic studies have implicated PAHs as risk factors for human cancer, the evidence reported to date has not been consistent. The purpose of this report is to describe the associations between occupational exposure to PAHs in the workplace and each of 14 types of cancer. A population-based, case-control study was carried out in Montreal to investigate associations between a large variety of environmental and occupational exposures on the one hand, and several types of cancer on the other. A detailed job history was obtained from each subject along with information on a number of potential confounders. Each job history was reviewed by a team of experts, who used this information to construct a corresponding history of occupational exposures. Among the PAH exposures considered were benzo(a)pyrene (B(a)P) and five categories of PAHs defined on the basis of the source material, namely, wood, petroleum, coal, other sources, and any source. Altogether, 3,730 cancer patients and 533 population controls were interviewed and their job exposure histories coded. For each of 14 types of cancer analyzed, three control groups were available: other cancer patients, population controls, and the pooled set of cancer and population controls. The associations between 14 cancer types and 6 PAH exposures were analyzed using logistic regression methods. For most types of cancer evaluated, there was no evidence of excess risk due to PAHs at the levels encountered in the occupations in which PAH exposure has been prevalent in the Montreal area. For a few cancer sites–the esophagus, the pancreas, and the prostate gland–there were suggestions of excess risk; these observations are noteworthy hypotheses for further investigation. For lung cancer, there appeared to be an increased risk due to PAHs among nonsmokers and light smokers, but not among heavy smokers.     

荧光分光光度法测定水产品中烷烃类、芳烃类污染物

目的：对使用荧光分光光度法测定水产品中烷烃类、芳烃类污染物的方法进行验证,并检测三类样品。方法：通过氢氧化钠-乙醇皂化处理,用正已烷萃取,用石油醚溶解,测量萃取物荧光强度值进行定量。结果：测得标准油在0.00～12.0μg/ml范围内线性关系良好,相关系数0.9999,检出限为0.2 mg/kg,平均回收率90.2%,RSD5.4%。结论：本法准确度、灵敏度高,检出限低,操作稳定性好。