羊胎免疫调节因子生物活性的研究

目的探讨不同相对分子质量 (Mr)及不同工艺方法获得的山羊羊胎免疫调节因子 (GEIF)生物活性效果。方法运用Ea玫瑰花环试验和T淋巴细胞转化试验进行对比分析。结果超滤法提取GEIF ,不同Mr(30 0 0、5 0 0 0和 10 0 0 0 )Ea玫瑰花环恢复率和T淋巴细胞转化率之间没有明显差异 ;超滤法提取GEIF ,Ea玫瑰花环恢复率和T淋巴细胞转化率均高于透析法。结论采用超滤法提取GEIF生物活性优于透析法 ,不同Mr 提取GEIF生物活性无明显差异。     

Quantitative imaging of arsenic and its species in goat following long term oral exposure

Severity of arsenic toxicity was reported to vary depending on its species. The present study reflects the status of different species of arsenic in goat following long-term exposure of arsenic leading to hepatic damage. The experiment was conducted with six black Bengal goats, which were administered with sodium arsenite orally at a dose rate of 2 mg kg⁻¹ daily for 84 days. Faeces, urine, hair and blood samples were collected from those animals at 14 days interval. Excretion of total arsenic was reduced from 56 days onwards through both faeces and urine indicating higher accumulation of arsenic in body. The speciation study revealed that urinary arsenic was mainly of organic type, whereas hair accumulated almost equal proportion of arsenite, arsenate and organo arsenicals. Goats excreted high proportion of organo arsenicals through faeces possibly due to hepatobiliary secretion of organo arsenic into the gut. Significantly elevated serum alanine aminotransferase and aspartate aminotransferase activities (p < 0.05) alongwith histopathological changes in liver indicated hepatotoxicity. The arsenite fraction increased and organic proportion decreased in urine as the time progressed, which indicates that arsenite gets methylated in liver of goat. The study thus alluded that the toxicity of arsenic would aggravate if the animals were exposed for long time as the hepatotoxicity progressed resulting in decreased methylation and formation of organo arsenicals and decreased excretions through urine.     

Selective speciation and determination of inorganic arsenic in water,food and biological samples

A procedure for the speciation of arsenic(III) and arsenic(V) in natural water samples has been established in the presented work. Arsenic(III) ions were quantitatively recovered on Alternaria solani coated Diaion HP-2MG resin at pH 7, while the recoveries of arsenic(V) was below 10%. Arsenic(V) in the mixing solution containing As(III) and As(V) was reduced by using KI and L(+) ascorbic acid solution, then the procedure was applied to determination of total arsenic. Arsenic(V) was calculated as the difference between the total arsenic content and As(III) content. The determination of arsenic was performed by using hydride generation atomic absorption spectrometry. The influences of some alkali, earth alkali and transition metals on the biosorption of arsenic(III) were investigated. The preconcentration factor was 35. The detection limits for As(III) (N = 20, k = 3) was found as 11 ng L⁻¹. The relative standard deviation and relative error of the determinations were found to be lower than 7% and 4%, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successively applied for the determination and speciation of inorganic arsenic in water, food and biological samples.     

Case-control study of male cancer patients exposed to arsenic-contaminated drinking water and tobacco smoke with relation to non-exposed cancer patients

The investigated data indicated that inorganic arsenic in drinking water is associated with increased mortality from different types of cancers. In the present study, biological samples (blood and scalp hair) of male subjects having lung and bladder cancers and non-cancerous subjects belonging to arsenic (As)-exposed area of southern parts of Pakistan were analysed for As contents. The As levels in drinking water of understudy area showed that sections of understudy population are exposed to arsenic concentrations, which was 3-15-fold higher than the permissible level (<10 μg/L). For comparative purposes the biological samples of matched male cancer patient, as referent patients belonging to big city (Hyderabad) who had used municipal treated water with low arsenic levels <10 μg/L, were also collected. The exposed cancer patients have 2-3-fold higher level of As in both biological samples compared to non-exposed case-matched cancerous male subjects. This study is compelling evidence in support of positive associations between arsenic-contaminated water, food and cigarette with different types of risks of cancer.     

Effect of environmental exposure of arsenic on cattle and poultry in nadia district, west bengal, India

A study was undertaken to evaluate an alternative source of arsenicosis in human food chain through livestock. Thirty milch cattle and 20 poultry birds along with their eggs were selected randomly from two endemic villages of Nadia district and one nonendemic villages of Hooghly district in West Bengal, India. Milk, feces, urine, and hair samples of cattle and feed materials, such as water and straw, were collected to analyze arsenic status. Arsenic concentration in egg yolk and albumen from poultry eggs and different poultry organs after culling was estimated. Distribution of arsenic in animal body indicates that major portion of arsenic was eliminated through feces, urine, and milk. Poultry egg yolk, albumen, and poultry products retain arsenic in all organs. Cows and poultry birds reared in endemic zone retain significantly higher concentration of arsenic. Consumption of egg, agricultural produces grown in contaminated soil, and milk might have produced arsenicosis and may be considered as alternative source of arsenic contamination.     

Arsenic speciation in human urine: are we all the same?

We studied the arsenic speciation in human urine samples by using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). We investigated the arsenic speciation in the urine collected from nine volunteers during a 3-day period after a meal of blue mussels, Mytilus edulis. We also studied the effect of cooking on the arsenic speciation. Arsenobetaine and dimethylarsinic acid (DMAA) were the major arsenic metabolites found in the urine samples. Significant amounts of unknown metabolites were also detected. The excretion patterns of arsenic from individuals were generally similar except for two subjects. One of whom excreted high amounts of arsenobetaine even though no arsenic-rich food was eaten for 3 days before the experiment. The results reveal that we need a better understanding of the metabolism of arsenic compounds by human.     

Interference in the quantitation of methylated arsenic species in human urine

The aim of this paper is to report on the presence of chemical interferences in the quantitation of methylated arsenic species in human urine when using a method based on selective volatile arsine species generation, chromatographic separation, and hydride generation atomic absorption spectrometry (HGAAS) detection. An abnormal profile of methylated arsenic species characterized by the absence of the peak corresponding to dimethylarsinic acid (DMA) was observed in urine from some individuals exposed to arsenic via drinking water and living in rural communities of northwestern Argentina. The absence of this peak persisted even after the addition of known amounts of DMA to the samples. However, the DMA peak appeared after urine digestion with hydrochloric acid (2M). Samples showing interferences were provided by individuals who had mate consumption and coca-leaf chewing habits. Because the relative proportions of methylated arsenic species present in urine have been used to evaluate the efficiency of the methylation process, interferences in the formation or detection of methylarsines may cause underestimation of As exposure and also lead to erroneous conclusions about relative biomethylation efficiencies. Therefore, we recommend that urine samples should be digested with 2M HCl before performing speciation analysis using HGAA techniques. Further studies on the impact of this type of interferences on other arsenic speciation methods are also required.     

Arsenic speciation in urine from acute promyelocytic leukemia patients undergoing arsenic trioxide treatment

Arsenic has been used successfully in clinical trials for treating acute promyelocytic leukemia (APL). Although sublethal doses of inorganic arsenic are used, little is known about the pharmacokinetics and metabolism of the high levels of arsenic in APL patients. To fill this important gap, this study describes the speciation of arsenic in urine from four APL patients treated with arsenic. Each patient was injected daily with an arsenite (As(III)) solution that contained 10 mg of As(2)O(3) precursor. Speciation analysis of the patient urine samples collected consecutively for 48 h, encompassing two intravenous injections of arsenic, revealed the presence of monomethylarsonous acid (MMA(III)), dimethylarsinous acid (DMA(III)), monomethylarsonic acid (MMA(V)), and dimethylarsinic acid (DMA(V)). The intermediate methyl arsenic metabolites, MMA(III) and DMA(III), were detected in most urine samples from all of the patients when a preservative, diethyldithiocarbomate, was added to the urine samples to stabilize these trivalent arsenic species. The major arsenic species detected in the urine samples from the patients were As(III), MMA(V), and DMA(V), accounting for >95% of the total arsenic excreted. The relative proportions of As(III), As(V), MMA(V), and DMA(V) in urine samples collected 24 h after the injections of As(III) were 27.6 +/- 6.1, 2.8 +/- 2.0, 22.8 +/- 8.1, and 43.7 +/- 13.3%, respectively. The relatively lower fraction of the methylated arsenic species in these APL patients under arsenic treatment as compared with that from the general population exposed to much lower levels of arsenic suggests that the high levels of As(III) inhibit the methylation of arsenic (inhibits the formation of methyl arsenic metabolites). The arsenic species excreted into the urine accounted for 32-65% of the total arsenic injected. These results suggest that other pathways of excretion, such as through the bile, may play an important role in eliminating (removing) arsenic from the human body when challenged by high levels of As(III).     

Measurement of arsenic bioavailability in soil using a primate model.

Several studies have shown limited absorption of arsenic from soils. This has led to increased interest in including measurements of arsenic relative bioavailability from soils in the calculation of risks to human health posed by arsenic-contaminated sites. Most of the information in the literature regarding arsenic bioavailability from soils comes from studies of mining and smelter sites in the western United States. It is unclear whether these observations are relevant to other types of arsenic-contaminated sites. In order to obtain information regarding arsenic bioavailability for other types of sites, relative bioavailability of arsenic from selected soil samples was measured in a primate model. Sodium arsenate was administered to five male Cebus apella monkeys by the intravenous and oral routes, and blood, urine, and feces were collected. Pharmacokinetic behavior of arsenic after intravenous administration and the fractions of dose excreted in urine and feces after both intravenous and oral doses were consistent with previous observations in humans. Soil samples from five waste sites in Florida (one from an electrical substation, one from a wood preservative treatment site, two from pesticide sites, and one from a cattle-dip vat site) were dried and sieved. Soil doses were prepared from these samples and administered orally to the monkeys. Relative bioavailability was assessed based on urinary excretion of arsenic following the soil dose compared with excretion following an oral dose of arsenic in solution. Differences in bioavailability were observed for different sites, with relative bioavailability ranging from 10.7 +/- 4.9% (mean +/- standard deviation) to 24.7 +/- 3.2% for the five soil samples. These observations, coupled with data in the literature, suggest limited oral bioavailability of arsenic in soils from a variety of types of arsenic-contaminated sites.     

A survey of arsenic species in Chinese seafood.

In the present report, thirty different types of Chinese edible seafood, including brown algae, red algae, fish, crab, shrimp, mussels, oysters, and clams, which are very popular foodstuffs in the Chinese kitchen, were examined for their total content of As as well as its different species. Total arsenic concentration in algae samples was 1.7-38.7 microg/g (dry weight), and 0.086-7.54 microg/g in fish and shellfish (wet weight), respectively. The arsenic species in seafood extracts were determined by using anion and cation exchange high performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICPMS). Arsenosugars were detected in all of the extracted algae samples (1.5-33.8 microg/g dry weight) and fish samples (0.018-0.78 microg/g wet weight). Arsenobetaine was detected in all of the extracted fish and shellfish samples (0.025-6.604 microg/g wet weight). In contrast, inorganic arsenic in fish and shellfish samples occurred at levels below 2% of the total arsenic. No inorganic arsenic was detected in the algae samples. This study provides information about the distribution pattern of arsenic species in seafood products. Since the major share of arsenic components in seafood is organic arsenic with a low toxicity, we can conclude that arsenic in seafood does not pose any risk to human health.     

Thio-dimethylarsinate is a common metabolite in urine samples from arsenic-exposed women in Bangladesh

Over the last 6 years, much work on arsenic species in urine samples has been directed toward the determination of the reduced dimethylated arsenic species, DMA(III), because of its high toxicity and perceived key role in the metabolism of inorganic arsenic. Recent work, however, has suggested that DMA(III) may at times have been misidentified because its chromatographic properties can be similar to those of thio-dimethylarsinate (thio-DMA). We analyzed by HPLC-ICPMS (inductively coupled plasma mass spectrometry) urine samples from 75 arsenic-exposed women from Bangladesh with total arsenic concentrations ranging from 8 to 1034 microg As/L and found that thio-DMA was present in 44% of the samples at concentrations ranging mostly from trace amounts to 24 microg As/L (one sample contained 123 microg As/L). Cytotoxicity testing with HepG2 cells derived from human hepatocarcinoma indicated that thio-DMA was about 10-fold more cytotoxic than dimethylarsinate (DMA). The widespread occurrence of thio-DMA in urine from these arsenic-exposed women suggests that this arsenical may also be present in other urine samples and has so far escaped detection. The work highlights the need for analytical methods providing specific determinations of arsenic compounds in future studies on arsenic metabolism and toxicology.     

Arsenic levels in tube-wells water, food, residents' urine and the prevalence of skin lesions in Yatenga province, Burkina Faso

The aim of the present study was to evaluate the levels of arsenic in tube-well water, food and residents' urines samples in Yatenga province, Burkina Faso. The prevalence of skin lesions was evaluated as well. The study was cross-sectional in design. It was conducted during April 2009. Permanent residents of 20 villages were included in the study. Water samples were collected from 31 tube-wells located in the selected villages. Tomatoes, cabbages, and potatoes produced in the selected village were randomly sampled. Arsenic content in water, food, and residents' urine was determined by atomic absorption spectrophotometry using hydride generation method. Finally, 240 people were examined by a medical doctor for skin lesions. Arsenic concentrations from the tube-well water ranged from 1 to 124 μg/l. Arsenic concentrations of more than one-half (52%) of the water samples exceeded the WHO guideline value (10 μg/l). No trace of arsenic was found in the samples of tomatoes, cabbages, and potatoes. Variation in arsenic concentrations in the urines was correlated to arsenic concentrations in tube-well water. Clinical examinations revealed that melanosis and keratosis were respectively identified in 29.26% and 46.34% of the population. Both conditions were observed in 24.39% of the population. The frequency of skin lesions was positively associated with the arsenic concentration in tube-well water. A great majority (89.53%) of those who had skin lesions were at least 18 years old. In conclusion, chronic arsenic poisoning remains a major public health problem in the province of Yatenga (Burkina Faso).     

Arsenic species contents at aquaculture farm and in farmed mouthbreeder (Oreochromis mossambicus) in blackfoot disease hyperendemic areas.

A study was conducted to measure the arsenic species in farmed mouthbreeder (Oreochromis mossambicus) and culture ponds in water in blackfoot disease (BFD) hyperendemic areas in Taiwan. The relationships between arsenic species of aquaculture ponds and farmed fish were also explored. Biota samples were extracted with methanol/water (1/1, v/v) using a Soxhlet extraction apparatus. The concentrations of arsenite As (III), arsenate As (V), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) of extracts were measured by high-performance liquid chromatography (HPLC) linked to a hydride generator and atomic absorption spectrometry (HG-AAS). Moreover, arsenobetaine (AB) was analyzed by HPLC linked to ultra violet (UV) and HG-AAS. Concentrations of arsenic species were determined in 68 mouthbreeder (O. mossambicus) samples and 21 culture ponds from Putai and Yichu Townships of Chiayi County and Hsuehchia and Peimen Townships of Tainan County. The mean arsenic levels of culture ponds in Putai, Yichu, Hsuehchia, and Peimen were 75.8, 15.1, 14.4, and 221.0 microg/l, respectively. The water of culture ponds was dominated by As (V). The inorganic arsenic percentage of fish (7.4%) was higher than that reported by other seafood surveys. Except for the MMA and As (III) levels, As (V), DMA, AB, and total arsenic levels in fish significantly increased with inorganic and total arsenic concentrations of the pond water. Inorganic arsenic species are more toxic than methyl arsenic species. Therefore the effect of inorganic arsenic species might result in a greater number of adverse health effects to the general public. It is of importance to evaluate the inorganic arsenic levels of farmed seafood in arsenic-contaminated areas.     

Lifelong inorganic arsenic compounds consumption affected blood pressure in rats

Chronic arsenic exposure is a known risk factor for cardiovascular disease and has a strong correlation with hypertension. Oxidative stress may be one of the major contributors to arsenic-induced hypertension. To investigate the antioxidative and CYP systems through which inorganic arsenic compounds may contribute to blood pressure elevation in rats, we administered 50 ppm arsenic (as arsenite and arsenate) in drinking water to Wistar rats for 200 successive days. Systolic blood pressure was determined every 20 days, and blood samples and tissues were collected at each time point for biological analysis. Compared to the control group, weight gain in the arsenic-exposed animals was slightly but significantly lower, whereas the relative weights of the various tissues was higher. Blood pressure was elevated until day 80 in both arsenic groups followed by a time-dependent change in the antioxidative enzyme system. The hypertensive effect remained until day 200 for arsenite when the change by arsenate was minimized. Patterns of antioxidative enzyme change differed between arsenite and arsenate. However, the most common marker of hypertension, the angiotensin-converting enzyme, showed no significant change in either arsenic group. CYP4A was highly expressed in both arsenic groups, particularly in the arsenite group. These results indicate that low but chronic arsenic exposure might cause elevated blood pressure and antioxidative interference. Furthermore, CYP4A might be more important than ACE in contributing to arsenic-induced hypertension.     

Toxicogenomic analysis of aberrant gene expression in liver tumors and nontumorous livers of adult mice exposed in utero to inorganic arsenic.

Arsenic is a known human carcinogen. We have reported that brief exposure of pregnant C3H mice to arsenite in their drinking water during gestation induced hepatocellular carcinoma (HCC) in male offspring after they became adults. Tumor formation is typically associated with multiple gene expression changes, and this study examined aberrant gene expression associated with transplacental arsenic hepatocarcinogenesis. Liver tumors and nontumorous liver samples were taken at necropsy from adult male mice exposed in utero to either 42.5 or 85 ppm arsenic as sodium arsenite or unaltered water from day 8 to 18 of gestation. Total RNA was extracted and subjected to microarray analysis. Among 600 genes, arsenic-induced HCC showed a higher rate of aberrant gene expression (>2-fold and p < 0.05, 14%) than spontaneous tumors (7.8%). Overexpression of alpha-fetoprotein, c-myc, cyclin D1, proliferation-associated protein PAG, and cytokeratin-18 were more dramatic in arsenic-induced HCC than spontaneous tumors. In nontumorous liver samples of arsenic-exposed animals, 60 genes (10%) were differentially expressed, including the increased expression of alpha-fetoprotein, c-myc, insulin-like growth factor binding protein-1, superoxide dismutase, glutathione S-transferases, and CYP2A4, and the depressed expression of CYP7B1. Real-time RT-PCR analysis largely confirmed these findings. This toxicogenomic analysis revealed several aberrant gene expression changes associated with transplacental arsenic carcinogenesis. It is indeed remarkable that expression changes occurred in adulthood even though arsenic exposure ended during gestation. Some of these aberrantly expressed genes could play a role in the development of arsenic-induced tumors, at least in the liver.     

ICP-MS法结合化学计量学用于枸杞子道地性的研究及安全性评价

目的:研究枸杞子中重金属及有害元素与道地性的相关性,并首次提出一种用于道地药材安全性评价的综合性策略.方法:该策略涵盖样品收集、分析测定、多元统计分析、安全性评价和风险评估5个步骤.样品经过微波消解后,采用电感耦合等离子体质谱(ICP-MS)法测定其重金属及有害元素的残留量,对结果进行聚类热图分析、主成分分析(PCA)...     

三氧化二砷对人大肠癌LoVo细胞血管内皮生长因子表达的影响

目的 探讨血管内皮生长因子(VEGF)在人大肠癌细胞株LoVo中的表达及三氧化二砷(As2O3)对其表达的影响.方法 应用实时定量PCR法和免疫细胞化学法检测As2O3干预前后LoVo结肠癌细胞中VEGF mRNA及VEGF蛋白表达.结果 LoVo大肠癌细胞表达VEGF,VEGF基因表达与蛋白表达呈正相关,且VEGF表达随着As2O3剂量的增加而下降.结论 VEGF在人结肠癌细胞LoVo中表达,As2O3可显著抑制VEGF的表达,呈剂量依赖性,表明As2O3具有抑制肿瘤血管生成的作用.     

Imatinib activity in vitro in tumor cells from patients with chronic myeloid leukemia in chronic phase and blast crisis

The aims of this study were to evaluate the feasibility of using the non-clonogenic fluorometric microculture cytotoxicity assay in drug sensitivity testing of tumor cells from patients with chronic myeloid leukemia. In nine samples (six chronic phase, three blast crisis), the drug sensitivities in tumor cells from blood versus from bone marrow and fresh tumor cells versus cryopreserved were compared. In 26 samples obtained in chronic phase (pretreatment), in six samples from patients in blast crisis and in the K 562 cell line, the activity of imatinib alone and in combination with cytarabine, vincristine, daunorubicin, interferon, arsenic trioxide and homoharringtonine was evaluated. All chronic myeloid leukemia chronic phase samples were sensitive to imatinib, with a mean IC50 at 10.3 mumol/l. The chronic myeloid leukemia samples from blast crisis (n=6) were significantly more sensitive to imatinib than the samples from chronic phase (n=26) (P<0.05), with an IC50 mean at 0.4 mumol/l. In blast crisis samples, significant positive interaction effects were observed between imatinib and all other tested drugs except for interferon. In chronic phase samples, interferon, daunorubicin and arsenic trioxide were the drugs with the highest frequency of positive interactions with imatinib (P<0.05). We conclude that the fluorometric microculture cytotoxicity assay may be a useful method for drug sensitivity testing in chronic myeloid leukemia patient samples from both chronic phase and blast crisis, and that testing primary tumor cells may have advantages over cell line studies. Imatinib shows a higher in vitro activity and more positive drug interactions in cells from blast crisis than chronic phase chronic myeloid leukemia patients. Combinations between imatinib and interferon, daunorubicin and arsenic trioxide may be interesting for future clinical trials in patients with chronic myeloid leukemia chronic phase.     

Toxicological effects and bioaccumulation in the freshwater clam (Corbicula fluminea) following exposure to trivalent arsenic

Contamination of aquatic environments by arsenic is a serious worldwide problem. The main objective of this work was to evaluate the response of a freshwater clam (Corbicula fluminea) to arsenic (As III) exposure and infer its potential as a biological indicator of contamination. Metallothioneins (MTs) were used as indicators of metalloid toxicity in combination with an histological and histochemical evaluation. After a period of acclimatization in the laboratory, 50 C. fluminea (0.4 g +/- 0.1) were exposed to different nominal concentrations of arsenic (100, 300, 500, and 1000 microg L(-1)) for 7 days. The concentration of total As III in the water and in the tissues of the organisms was determined by atomic absorption spectrometry, and MTs were quantified through differential pulse polarography. Results suggest that the organisms exposed to the concentrations of 300 and 1000 microg As L(-1) accumulated the highest levels of As III in the tissues (17 +/- 9 and 15 +/- 3 microg g(-1) distilled water, respectively), which was confirmed through histochemical analysis. An apparent induction of MTs was also observed in the organisms exposed to As III, suggesting that C. fluminea possesses some capacity for arsenic regulation. The results suggest that the induction of MTs may be of high interest as a biomarker for arsenic contamination in aquatic environments, and confirms the potential of C. fluminea as a biological indicator.