Pb speciation and elemental distribution in leeks by micro X-ray fluorescence and X-ray absorption near-edge structure.

Vegetables are crucial to a human diet as they supply the body with essential vitamins, minerals, etc. Heavy metals that accumulate in plants consequently enter the food chain and endanger people's health. Studying the spatial distribution and chemical forms of elements in plant/vegetable tissues is vital to comprehending the potential interactions between elements and detoxification mechanisms. In this study, leek plants and soil from vegetable gardens near lead-zinc mines were collected and cultivated with 500 mg L-1 PbNO3 solutions for three weeks. Micro X-ray fluorescence was used to map the distribution of Pb and other chemical elements in leek roots, and X-ray absorption near-edge spectroscopy was used to assess the Pb speciation in leek roots and leaves. These findings demonstrated that Pb, Cu, Mn, Cr, Ti and Fe were detected in the outer rings of the root's cross section, and high-intensity points were observed in the epidermis. Zn, K and Ca, on the other hand, were distributed throughout the root's cross section. Leek root and leaf contained significant quantities of lead phosphate and basic lead carbonate at more than 80%, followed by lead sulfide (19%) and lead stearate (11.1%). The capacity of leek roots to convert ambient lead into precipitated lead and fix it on the root epidermis and other inner surfaces is a key mechanism for reducing the toxic effects of Pb.

Improvement of Qilin pills on male reproductive function in tripterygium glycoside-induced oligoasthenospermia in rats.

This study established an oligoasthenospermic rat model using tripterygium glycosides (TGs) and investigated the mechanism by which Qilin pills (QLPs) ameliorate reproductive hypofunction. Thirty-two male Sprague Dawley rats were allocated to four equal-sized groups: (1) the control group received continuous physiological levels of saline; (2) the oligoasthenospermia model group was induced with TGs by daily intragastric administration for 28 days; (3 and 4) oligoasthenospermic rats were treated intragastrically with low dose (1.62 g kg-1  d-1 ) and high dose (3.24 g kg-1  d-1 ) of QLPs once daily for 60 days. The QLP-treated rats showed a marked increase (p < .05) in testicular mass, testicular index and semen parameters compared with the untreated rats. Histopathologically, the QLP-treated groups exhibited restored seminiferous tubules in contrast to the model group. Reactive oxygen species and malondialdehyde levels were dramatically decreased (p < .05) in the testes of the QLP-treated rats. QLP treatment partly reverted (p < .05) the circulatory levels of reproductive hormones (FSH, LH, testosterone, prolactin and SHBG) and hepatic and renal function (AST, Cr and urea). Our results showed that oral QLP treatment had a curative effect on the testicular mass, sperm quality, testicular pathomorphology, antioxidants, plasmatic hormones, and liver and renal function of rats.

Effects of nanotoxicity on female reproductivity and fetal development in animal models.

The extensive application of nanomaterials in industry, medicine and consumer products has raised concerns about their potential toxicity. The female population is particularly vulnerable and deserves special attention because toxicity in this group may impact both female reproductivity and fetal development. Mouse and zebrafish models each have their own unique features and studies using these models to examine the potential toxicity of various nanoparticles are compared and summarized in this review. Several nanoparticles exhibit detrimental effects on female reproductivity as well as fetal development, and these adverse effects are related to nanoparticle composition, surface modification, dose, exposure route and animal species. Limited studies on the mechanisms of nanotoxicity are also documented and reviewed herein.

[XANES study of lead speciation in duckweed].

Qixiashan lead-zinc mine of Nanjing was one of the largest lead zinc deposits in East China Its exploitation has been over 50 years, and the environmental pollution has also been increasing. The lead concentration in the local environment was high, but lead migration and toxic mechanism has not been clear. Therefore, biogeochemistry research of the lead zinc mine was carried out. Using ICP-MS and Pb-L III edge XANES, lead concentration and speciation were analyzed respectively, and duckweed which can tolerate and enriched heavy metals was found in the pollution area. The results showed that the lead concentration of duckweed was 39.4 mg x kg(-1). XANES analysis and linear combination fit indicated that lead stearate and lead sulfide accounted for 65% and 36.9% respectively in the lead speciation of duckweed, suggesting that the main lead speciation of duckweed was sulfur-containing lead-organic acid.

[In vivo determination of Pb in human bone by using X-ray fluorescence analysis].

The data of in vivo XRF Pb in human bone were obtained within China by using the in vivo XRF set. The K series X-ray of Pb were applied to determine the in vivo Pb concentration in tibia and calcaneus among Chinese mainland residents. For general population, the weighted average of Pb in bone was 0.4-22.7 microg x (lead g bone mineral)(-1). The uncertainty was 7.0-12.5 microg x (lead g bone mineral)(-1), and the average minimun detection limit was 20.3 microg x (lead g bone mineral)(-1). For residents from pollution area, the maximum Pb in bone reached up to 73.9 microg x (lead g bone mineral)(-1).

[Determination of trace nickel in bi-based superconductor powder by inductively coupled plasma atomic emission spectroscopy after separation with anion exchange resin and extraction with methylbenzene].

A new method for the determination of trace nickel in superconductor powder by ICP-AES was proposed. The instrument parameters were optimized, and the matrix effects as well as the method of eliminating interferences were also studied systemically. The results showed that matrix interference in the superconductor powder was serious when the amount of matrix increased, and the repeatability as well as the accuracy was poor, so it was necessary to used separation and preconcentration to improve the accuracy and precision. In this experiment, Ni-diacetyl dioxime complexes were enriched by toluene extraction in alkaline condition after eliminating the interference of major element Bi and partial Pb, Sr, Ca and Cu by eluting with anion exchange resin, then the Ni-complexes were back extracted by diluted hydrochloric acid. The enrichment conditions were investigated in detail and the recovery rate of Ni was higher than 95%. Under the optimal condition, an artificial sample was analysed, the result showed that the found values were identical with reference values, and the RSD and detection limit were 1.9% and 0.19 microg x g(-1), respectively. The method has been applied to the determination of trace nickel in Bi-based superconductor powder samples with satisfactory results.

Magnetic resonance spectroscopy on hepatocellular carcinoma after transcatheter arterial chemoembolization.

BACKGROUND AND OBJECTIVE: Proton magnetic resonance spectroscopy (MRS) of the liver in vivo is in experimental phase. MRS observation on liver cancer after transcatheter arterial chemoembolization (TACE) has seldom been reported. This study was to investigate the value of MRS in assessing the metabolic changes of hepatocellular carcinoma (HCC) after TACE. METHODS: Twenty-five consecutive patients with pathologically-confirmed HCC received 1H MRS of all hepatic lesions using 1.5T whole body MR scanner before TACE and at 3-10 days after TACE. Choline-to-lipid (Cho/Lip), glucogen/glucose-to-lipid (Glu/Lip), and glytamine/glutamate-to-lipid (Glx/Lip) ratios were measured and analyzed statistically. RESULTS: The Cho/Lip, Glu/Lip, and Glx/Lip ratios were 0.21 +/- 0.08, 0.11 +/- 0.05, 0.28 +/- 0.10 before TACE, respectively, and were 0.10 +/- 0.08, 0.07 +/- 0.07, 0.18 +/- 0.12 after TACE, respectively, with significant differences (P < 0.05). CONCLUSIONS: Using MRS can evaluate the early metabolic responses of HCC to TACE.

[The study of inhibiting heart rate and rapidly terminating atrial flutter of ibutilide on canine].

OBJECTIVE: To observe the electrophysiological effects of ibutilide on canine and to explore the potential mechanisms of ibutilide on terminating atrial flutter. METHODS: Eighteen mongrel dogs were anesthetized and intubated. The heart was exposed through thoracotomy for electrodes implantation. The electrophysiologic variables (heart rate, the conduction of intraatrium and interatrium, the conduction ratio of isthmus, the effective refractory period) were measured in the absence or presence of ibutilide (10 minute infusion with 0.10 mg/kg ibutilide, 30 minutes later with a maintaining dose of 0.01 mg/min). RESULTS: Ibutilide significant suppressed sinus atrial node function, the peak effect was observed at 20 - 30 min post drug infusion and heart rate returned to normal at 2 hours post infusion. Post ibutilide infusion, 1 canine developed sinus pause for 5 seconds and 2:1 atrioventricular conduction block was evidenced in another canine. The atrial, ventricular and pulmonary vein effective refractory periods were all significant prolonged (all P < 0.05) post ibutilide infusion. However, conduction of intraatrium, interatrium and isthmus remained unchanged post ibutilide infusion (all P > 0.05). CONCLUSIONS: Ibutilide could suppress sinus atrial node and the atrioventricular node function. The mechanism of ibutilide on rapidly terminating atrial flutter might be related to the prolongation of the refractory periods which might then result in the reduction of the whole excitable gap of the reentrant circuit and induce proceed inability of reentrant wavefront.

Clinical efficacy of acetylcysteine combined with tetrandrine tablets in the treatment of silicosis and the effect on serum IL-6 and TNF-α.

Clinical efficacy of acetylcysteine combined with tetrandrine tablets in the treatment of silicosis and the effect on serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in patients with silicosis was investigated. One hundred and ninety-six patients with silicosis admitted to Qingdao Central Hospital, aged 40 to 70 years, were collected by prospective analysis. The patients were divided into two groups according to the different methods of treatment. The 108 patients in the control group received routine treatment, including anti-inflammatory, cough and asthma relief and 88 patients in the observation group were treated with tetrandrine combined with N-acetylcysteine on the basis of routine treatment. The curative effect of the two groups was analyzed by X-ray, and the incidence of adverse reactions was compared between the two groups. There was no significant difference in the effective rate between the two groups (P>0.05). After treatment, respiratory rate (RR) decreased, and forced vital capacity (FVC), and first second forced expiratory volume (FEV1) increased in both groups (P<0.05). RR in the observation group was lower than that in the control group (P<0.05), FVC and FEV1 were higher than those in the control group (P<0.05). There was no significant difference in serum IL-6 and TNF-α levels between the two groups before treatment (P>0.05). After treatment, the levels of IL-6 and TNF-α in the two groups decreased (P<0.05), and the IL-6 and TNF-α levels in the observation group after treatment were significantly lower than those in the control group (P<0.05). According to the effect of clinical treatment, the patients were re-divided into two groups. In conclusion, tetrandrine combined with acetylcysteine can effectively improve the clinical therapeutic effect of silicosis and alleviate the degree of inflammatory reaction in patients with silicosis. The levels of IL-6 and TNF-α in peripheral blood are valuable for the clinical treatment of silicosis.

The association of serum and vitreous adropin concentrations with diabetic retinopathy.

OBJECTIVE: Adropin, a newly identified regulatory protein encoded by Enho gene, is correlated with insulin sensitivity and diabetes. The aim of this study is to determine whether serum and vitreous adropin concentrations are correlated with the presence of diabetic retinopathy. METHODS: A population of 165 patients with type 2 diabetes mellitus (52 without diabetic retinopathy, 69 with non-proliferative diabetic retinopathy and 44 patients with proliferative diabetic retinopathy) was enrolled in this study. The control group enrolled 68 healthy subjects who had underwent vitrectomy for retinal detachment. Serum and vitreous adropin concentrations were examined using enzyme-linked immunosorbent assay method. RESULTS: Control subjects had significantly higher serum and vitreous adropin concentrations compared with diabetic patients. Serum and vitreous adropin concentrations in proliferative diabetic retinopathy patients were significantly reduced compared with those in non-proliferative diabetic retinopathy patients and type 2 diabetes mellitus patients without diabetic retinopathy. In addition, there were lower serum and vitreous adropin concentrations in non-proliferative diabetic retinopathy patients compared with type 2 diabetes mellitus patients without diabetic retinopathy. Logistic regression analysis revealed that serum and vitreous adropin were associated with a decreased risk of type 2 diabetes mellitus and diabetic retinopathy. CONCLUSION: Serum and vitreous adropin concentrations are negatively associated with the presence of diabetic retinopathy.

Subcellular Distribution and Chemical Forms of Pb in Corn: Strategies Underlying Tolerance in Pb Stress.

Studying the accumulation position and forms of heavy metals (HMs) in organisms and cells is helpful to understand the transport process and detoxification mechanism. As typical HMs, lead (Pb) subcellular content, localization, and speciation of corn subcellular fractions were studied by a series of technologies, including transmission electron microscopy, inductively coupled plasma mass spectrometry, and X-ray absorption near edge structure. The results revealed that the electrodense granules of Pb were localized in the cell wall, intercellular space, and plasma membranes. About 71% Pb was localized at the cell wall and soluble fraction. In cell walls, the total amount of pyromorphite and Pb carbonate was about 80% and the remaining was Pb stearate. In the nuclear and chloroplast fraction, which demonstrated significant changes, major speciations were Pb sulfide (72%), basic Pb carbonate (16%), and Pb stearate (12%). Pb is blocked by cell walls as pyromorphite and Pb carbonate sediments and compartmentalized by vacuoles, which both play an inportant role in cell detoxification. Besides, sulfur-containing compounds form inside the cells.

[The relationship of paroxysmal atrial fibrillation and regional sympathetic innervations in the atria and pulmonary veins: experiment with dogs].

OBJECTIVE: To test the hypothesis that regional sympathetic innervation in the atria and pulmonary veins are correlated with atrial fibrillation (AF). METHODS: Sixteen adult mongrel dogs underwent thoracotomy under general anesthesia. Bilateral cervical vagal trunks were decentralized. Multipolar catheters were placed into right atrial appendage (RAA), left atrial appendage (LAA), left atrium (LA), left superior pulmonary vein (LSPV), left inferior pulmonary vein (LIPV), right superior pulmonary vein (RSPV), and left inferior pulmonary vein (LIPV). The bilateral sympathovagal trunks were stimulated, S1S1 burst stimulation and S1S2 stimulation procedure were performed on different points of RAA, LAA, LA, LSPV, LIPV, RSPV, and LIPV. The TF thus induced was monitored. After that, the dogs were killed with their hearts and lungs were taken out. Immunocytochemical staining of cardiac nerves was performed using anti-tyrosine hydroxylase (TH) antibodies. The nerve fiber density was counted manually for each case and expressed as the mean number per slice. RESULTS: Two dogs died during the experiment and the whole procedure was completed on 14 dogs. There was no significant difference in the AF induction rate among the most points, however, the AF induction rate of the RIPV was significantly lower than those of the other points (all P < 0.05). The levels of density of TH-positive nerves in the atria and atrial appendages were significantly higher than those in the pulmonary veins (P = 0.02). The density of TH-positive nerves in the dogs with AF was significantly higher than that in the dog without AF (P < 0.05). The innervation of sympathetic nerves in atria and pulmonary veins was highly correlated to the induction of atrial fibrillation (r = 0.83). CONCLUSION: Regional sympathetic hyperinnervation plays an important role in atrial fibrillation induction.

[Vagal effects on inducibility of atrial fibrillation at different sites of pulmonary veins after autonomic denervation].

OBJECTIVE: To investigate the vagal effects on the inducibility of atrial fibrillation (AF) at different sites of pulmonary vein after autonomic denervation. METHODS: The bilateral cervical vagal trunks of 10 male mongrel dogs were isolated and decentralized. The ansae subclaviae were exposed, ligated, and cut. Needle electrodes were inserted into the subcutaneous tissue of the 4 extremities to record the myocardiogram. Right ventricle electrode was introduced via femoral vein and an electrode with 4 poles was sutured with the right appendage (RAA), left appendage (LAA), left atrium (LA), left superior pulmonary vein (LSPV), right superior pulmonary vein (RSPV), left inferior pulmonary vein (LIPV), and right inferior pulmonary vein (RIPV) respectively. Local burst stimulation (S1S1 = 80 ms, impulse duration = 0.5 ms) was performed on these sites to record the baseline AF inducibility. When sinus cardiac arrest for 2 s or complete atrio-ventricular block occurred programmed bilateral vagal nerves stimulation (VNS) was performed with the frequency of 12.5 Hz, impulse duration of 0.5 ms, and voltage of 5-8 V. Atropine 0.04 mg/kg was dripped intravenously. The changes of AV inducibility were observed. RESULTS: In the baseline state, S1S1 programmed stimulation on all the sites evoked single or multiple atrial premature beats and short runs of atrial tachycardia, only a few sites induced AF. However, S1S1 programmed stimulation combined with VNS significantly increased the frequencies of induced AV at the sites of 4 PVs (P < 0.05, P < 0.01). When atropine was dripped the AV induction rates at all sites did not changed significantly (all P > 0.05). CONCLUSION: Vagal nerve may play an important role in the initiation of AF originating from pulmonary veins.

Circle quorum system-based non-stop network service model.

Rapid developments in network systems of business service have resulted in more reliance on distributed computing, typified by "subscriber/push" architectures. Unfortunately, frequent and unexpectable network failures were routine, and downtime was not in hours, but in days. High availability has become the most important factor decreasing business risk and improving Quality of Service. Cluster technology has solved the non-stop problem on Local Area Network. However, most technologies including cluster today fail to ensure the non-stop Internet service based on Routers. With good performance on high availability and fault tolerance, quorum systems are very suitable for application to distributed business service networks. In this work, we modeled and developed a non-stop Internet service system based on a new quorum system, circle quorum system, for Boston Mutual Fund Broker, US. With five protocols, it provided highly available data services for clients on Internet.

Experimental research on the in vitro antitumor effects of Crataegus sanguinea.

Crataegus sanguinea is a wild plant, which has been widely grown in the north and south of the Tianshan mountains in Xinjiang. In order to explore their anti-cancer properties, edible wild plants from Xinjiang have been tested for their antitumor properties. We used Ames tests, mouse bone marrow polychromatic erythrocytes micronucleus tests, and tumor cells cultured in vitro to study the anti-mutagenic and anti-tumor effects of C. sanguinea extract. We have shown that C. sanguinea has anti-mutagenic effect, but no mutagenicity. Cell culture in vitro experiments show that there is no inhibition of growth or increase in cell death on normal mouse fibroblasts, but a stronger inhibition of cell growth and an increase in cell death of Hep-2 and MGC-803 tumor cells. The results of this study illustrate that C. sanguinea extract has both anti-mutagenic and anti-tumor effects.

Chronic stress promoted the growth of ovarian carcinoma via increasing serum levels of norepinephrine and interleukin-10 and altering nm23 and NDRG1 expression in tumor tissues in nude mice.

The current study aimed to examine the effects and underlying mechanisms of chronic psychological stress on the growth of ovarian carcinoma. Human ovarian carcinoma cells SKOV-3 were subcutaneously inoculated into nude mice to establish an ectopic mouse model. The animals were experimentally stressed 6 h daily for a total of 42 days with a physical restraint system. We examined the effects of stress on the growth of tumor cells that were inoculated 7 days after the initiation of stress. The growth of SKOV-3 xenografts in the stress group showed a more rapid trend than that in the control. The mean weight of tumors that were removed at the end of the experiment increased by 71.7% in the stress group as compared to the control. In order to explore the underlying mechanisms, we first determined the serum levels of norepinephrine (NE) and interleukin 10 (IL-10) in the mice using an enzyme-linked immunoabsorbent assay (ELISA) and then analyzed protein expression profiles of SKOV-3 xenografts using a proteomics-based approach combining two-dimensional electrophoresis with ultra performance liquid chromatography-electrospray tandem mass spectrometry (nanoUPLC-ESI-MS/MS). Results demonstrated that serum levels of NE and IL-10 were obviously increased in the mice receiving 6 h of immobilization daily for 42 days. In xenografts exposed to stress, a tumor promoting protein nm23 was significantly upregulated while a tumor suppressing protein NDRG1 was obviously downregulated, which were confirmed by subsequent Western blot analysis. Results obtained in the current study suggested that chronic stress promoted the growth of ovarian carcinoma in nude mice through increasing serum levels of NE and IL-10 and altering nm23 and NDRG1 expression in tumor tissues.

Elderly patients and coronary heart disease on response to treadmill exercise test.

To study the response of the cardiovascular system, to exercise tolerance in-patients over 75 years old with coronary heart disease (CHD), and to evaluate the significance of the parameters of the treadmill exercise test (TET). 110 patients received TET and coronary artery angiography. They were divided into two groups: the elderly patients group included 50 patients over 75 years old, and the control group included 60 patients under 60 years old. (1) With aging, there were much more CHD patients in the positive TET (P < 0.05) than in the negative TET (P > 0.05). (2) The parameters of TET for the elderly CHD patients group, included exercise time, peak heart rate, and the onset of ST depression, were lower than the control group (P < 0.05). There was no statistical significance between the two groups in the extent and duration of ST depression (P < 0.05). (1) In TET, the elderly patients had the higher diagnostic value on CHD. (2) The elderly patients with CHD had the lower endurance to exercise test.

Effects of ibutilide on canine cardiac pacing threshold and on induction rates of atrial fibrillation.

This study aims to observe the effects of ibutilide on canine cardiac pacing threshold and on induction rates of atrial fibrillation. Eighteen mongrel dogs were anesthetized and administrated with ibutilide. The pacing thresholds and induction rates of atrial fibrillation were measured with and without ibutilide (10-min infusion dose was 0.10 mg kg(-1), followed by a maintaining dose of 0.01 mg min(-1) 30 min later). This study found that ibutilide increases pacing thresholds in dogs. Moreover, there were significant differences between pacing thresholds with and without ibutilide (P < 0.05). Further, ibutilide significantly reduces the induction rates of atrial fibrillation (P < 0.05). Our findings indicate that pacing voltage changes should be closely monitored in patients taking anti-arrhythmic drugs, who are treated with cardiac stimulation or have undergone pacemaker implantation. We also found that ibutilide is an effective drug in preventing or controlling atrial fibrillation.

Identification of obstructive sleep apnea syndrome by ambulatory electrocardiography: clinical evaluation of time-domain and frequency-domain analyses of heart rate variability in Chinese patients.

The application of ambulatory electrocardiography to identify obstructive sleep apnea syndrome (OSAS) patients was evaluated using time-domain and frequency-domain analyses of heart rate variability (HRV). For this, overnight sleep pattern was investigated in 95 individuals (48 OSAS(+) patients and 47 OSAS(-) controls) by polysomnography and 24-h ambulatory electrocardiography. Apnea scores were calculated using two different HRV analyses. Average age and body mass index, and percentages of men and of patients with history of hypertension and/or diabetes were higher in study group as compared with control group. PNN50(night), SDNNI(day-night) and SDNNI(day-night) in time-domain analysis were more sensitive than other indices. In frequency-domain analysis, mean night-time total power, night-time VLF power, night-time LF power, and the difference between these measures in day and night were significantly higher in study group. LF/HF ratio was also significantly higher in study group in day-time or night-time with a significant difference (P < 0.05) between day and night. At sleep apnea risk score >4, sensitivity, specificity, and positive predictive value were, respectively, 81.25, 46.81, and 64.21%. At sleep apnea risk scores >5, 6, or 7, the specificity increased, while the sensitivity and positive predictive value decreased. In conclusion, time-domain and frequency-domain HRV analyses are useful methods for OSAS screening, and the frequency-domain analysis is more sensitive.

Effects of ibutilide on inhibiting heart rate and rapidly terminating atrial flutter in canine.

Ibutilide is a newer class-III antiarrhythmic agent approved for clinical use. We sought to investigate its electrophysiological effects in canines and also the underlying mechanism of conversion of atrial flutter (AFL). For this purpose, 15 male mongrel dogs were anesthetized, intubated with tracheal tube, and heart was exposed and connected to electrodes. Electrophysiologic variables were measured with and without ibutilide (10-min infusion-dose: 0.10 mg/kg; 30-min later, maintaining dose: 0.01 mg/min) which included heart rate, conduction of intra- and inter-atrium, conduction ratio of isthmus, and ERP. Ibutilide had a significant inhibitory effect on sinus atrial node, peak response time was 20-30 min, and heart rate returned to the baseline after 2 h. One canine had 5 s sinus pause, and the other had 2:1 atrioventricular conduction post-administration. Atrial, ventricular, and pulmonary vein ERP was significantly prolonged (P < 0.05). No significant differences were observed regarding conduction of intra-atrium, inter-atrium, and isthmus. It was, therefore, concluded that ibutilide had suppressive effect on sinus atrial and atrioventricular nodes. Ibutilide rapidly terminated AFL due to the reentrant wave front's inability to proceed as the refractory period was protracted and hence caused the whole excitable gap of the reentrant circuit to be affected by refractoriness.