Trace Level Detection of Bisphenol A Analogues and Parabens by LC-MS/MS in Human Plasma from Malaysians.

In this study, a novel LC-MS/MS method was designed using a simple extraction procedure that was scientifically developed to capture the most relevant bisphenol A (BPA) analogues (BPB, BPF, BPS, and BPAF) and parabens (propylparaben, ethylparaben, butylparaben, and methylparaben) in human plasma. The LC-MS/MS method was validated using US FDA guidelines, and all validation requirements were satisfactory. This is the method that allows for the detection of plasma bisphenols and parabens in one run and is also the fastest BPA analogue and paraben detection technique for human plasma. The method was used to analyze samples from 150 healthy volunteers from Malaysia who enrolled in the study. No BPB was detected in any of the volunteers; however, 99.3% were positive for BPF. Only 24% and 10.7% of volunteers were positive for BPAF and BPS, respectively. A high percentage of volunteers were negative for propylparaben, ethylparaben, butylparaben, and methylparaben (56%, 68%, 86.7%, and 83.3%, respectively). These results suggest that persons in Malaysia are exposed to different BPA analogues and parabens, from both the daily use of products (cosmetic and plastic products) and the environment.

Validation of a simple extraction procedure for bisphenol A identification from human plasma.

The general population is exposed to bisphenol A (BPA) orally, parenterally, transdermally, and environmentally as a result of the use of BPA in food packaging, plastics, and personal care products. The majority of the population nowadays (91-99%) has detectable levels of BPA inside their body. In this study, we successfully performed an inexpensive, rapid, and simple protein precipitation procedure for extraction of BPA from human plasma, followed by analysis by LC-MS/MS. This method was specifically developed for handling large numbers of samples with minimum cost and volume of sample. The developed method was accurate, precise, and reproducible for quantification of BPA from human plasma samples in the concentration range of 10-2000 ng/mL. The method was performed on samples from 150 healthy volunteers who were enrolled in the study. The mean of observed BPA level was 2.22 ± 9.91 ng/mL. Higher BPA levels were observed for females compare to that of males (p-value = 0.002), the BPA levels were higher in participants 33 years of age and older compared to those less than 33 years of age (p-value = 0.000), then the BPA levels higher in subjects with tap water as source of drinking (p-value = 0.005). This method may be valuable for general risk assessment of BPA for a large and varied population because of its efficiency and economical aspects.

Performance of chlorination process during nanofiltration of sulfonamide antibiotic.

The effectiveness of combined nanofiltration and disinfection processes was studied by comparing the pre-disinfection and post-disinfection when in combination with nanofiltration. Four types of sulfonamide (sulfanilamide, sulfadiazine, sulfamethoxazole, and sulfadimethoxine) were chosen as substrates, with sodium hypochlorite as a disinfectant. A laboratory-scale nanofiltration system was used to conduct the following sets of experiment: (1) a pre-chlorination system, where the free active chlorine (FAC) was added to the membrane influent; and (2), a post-chlorination system, where the FAC was added to the membrane effluent. Overall, the pre-disinfection nanofiltration system showed higher sulfonamide removal efficiency compared to the post-chlorination nanofiltration system (>99.5% versus >89.5%). In the case of limited FAC ([FAC]0: [sulfonamide]0≤1), the removal efficiency for the post-chlorination nanofiltration system was higher, due to the prior nanofiltration process that could remove 12.5% to 80% of sulfonamide. The flux of the treated feed system was considerably higher than in the untreated feed system; however, the membrane was observed to be slightly damaged due to residual chlorine attack.

Extract of Woodfordia fruticosa flowers ameliorates hyperglycemia, oxidative stress and improves ß-cell function in streptozotocin-nicotinamide induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The art of Ayurveda and the traditional healing system in India have reflected the ethnomedicinal importance of the plant Woodfordia fruticosa Kurtz, which demonstrates its vast usage in the Ayurvedic preparations as well as in the management of diabetes by the traditional healers. AIMS OF STUDY: The study aimed to ascertain the antidiabetic potential of W. fruticosa flower methanolic extract (WF) on Streptozotocin (STZ)-nicotinamide-induced diabetic rat model. MATERIALS AND METHODS: Diabetes was induced in Sprague Dawley (SD) rats by STZ-nicotinamide and thereafter diabetic rats were treated with three different doses of WF (100, 200 and 400mg/kg body weight) respectively and glibenclamide as a positive control. Biochemical parameters such as blood glucose, serum insulin and C-peptide levels were measured with oxidative stress markers. Furthermore, histology of liver and pancreas was carried out to evaluate glycogen content and ß-cell structures. Moreover, immunohistochemistry and western blot analysis were performed on kidney and pancreas tissues to determine renal Bcl-2, pancreatic insulin and glucose transporter (GLUT-2, 4) protein expression in all the experimental groups. RESULTS: The acute toxicity study showed non-toxic nature of all the three doses of WF. Further, studies on diabetic rats exhibited anti-hyperglycemic effects by upregulating serum insulin and C-peptide levels. Similarly, WF shown to ameliorate oxidative stress by downregulating LPO levels and augmenting the antioxidant enzyme (ABTS). Furthermore, histopathological analysis demonstrate recovery in the structural degeneration of ß-cells mass of pancreas tissue with increase in the liver glycogen content of the diabetic rats. Interestingly, protective nature of the extract was further revealed by the immunohistochemical study result which displayed upregulation in the insulin and renal Bcl-2 expression, the anti apoptosis protein. Moreover, western blot result have shown slight alteration in the GLUT-2 and GLUT-4 protein expression with the highest dose of WFc treatment, that might have stimulated glucose uptake in the pancreas and played an important role in attenuating the blood glucose levels. CONCLUSION: The overall study result have demonstrated the potential of WF in the management of diabetes and its related complications, thus warrants further investigation on its major compounds with in depth mechanistic studies at molecular level.

Concentrations and profiles of urinary polycyclic aromatic hydrocarbon metabolites (OH-PAHs) in several Asian countries.

Concentrations of 12 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were determined in 306 urine samples collected from seven Asian countries (China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam) by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The total concentrations of OH-PAHs found in the seven Asian countries were in the following increasing order: Malaysia (median: 2260 pg/mL) < Japan (4030 pg/mL) < China (5770 pg/mL) < India (6750 pg/mL) < Vietnam (8560 pg/mL) < Korea (9340 pg/mL) < Kuwait (10170 pg/mL). The measured urinary concentrations of 1-hydroxypyrene (1-PYR) in samples from Malaysia, Korea, and Japan (∼ 100 pg/mL) were similar to those reported for North America and Western Europe. The concentrations of 1-PYR in urine samples from China, India, and Vietnam were 4-10 times higher than those reported for other countries, thus far. Among the 12 OH-PAH compounds analyzed, hydroxynaphthalene (NAP: sum of 1-hydroxynaphthalene and 2-hydroxynaphthalene) was the dominant compound (accounting for 60-90% of total OH-PAHs), followed by hydroxyphenanthrene (PHEN: sum of 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, and 9-hydroxyphenanthrene [3-16%]), 2-hydroxyfluorene (3-20%), and 1-PYR (2-8%). The total daily intakes (DIs) of PAHs were estimated based on the urinary concentrations of their metabolites. The DIs of naphthalene were found to be higher for populations in Korea, Kuwait, and Vietnam (> 10 µg/day) than those of the other countries studied (∼ 5 µg/day). The DIs of phenanthrene and pyrene (> 10 µg/day) in the populations of China, India, and Vietnam were higher than those estimated for the populations in the other countries studied (∼ 5 µg/day).

The methanolic fraction of Centratherum anthelminticum seed downregulates pro-inflammatory cytokines, oxidative stress, and hyperglycemia in STZ-nicotinamide-induced type 2 diabetic rats.

This study aimed to ascertain the potential of Centratherum anthelminticum seeds methanolic fraction (CAMFs) for the management of type 2 diabetes and its associated complications. CAMFs was initially tested on ß-TC6 cells for H(2)O(2)-induced nuclear factor-κB (NF-κB) translocation effects. The result displayed that CAMFs significantly inhibited NF-κB translocation from cytoplasm into the nucleus, dose-dependently. Furthermore, a 12-week sub-chronic CAMFs study was carried out on streptozotocin (STZ)-nicotinamide-induced type 2 diabetic rat model to evaluate glycemia, essential biochemical parameters, lipid levels, oxidative stress markers, and pro-inflammatory cytokines level. Our study result showed that CAMFs reduced hyperglycemia by increasing serum insulin, C-peptide, total protein, and albumin levels, significantly. Whereas, elevated blood glucose, glycated hemoglobin, lipids and enzyme activities were restored to near normal. CAMFs confirmed antioxidant potential by elevating glutathione (GSH) and reducing malondialdehyde (MDA) levels in diabetic rats. Interestingly, CAMFs down-regulated elevated tumor necrosis factor α (TNF-α), interleukin (IL)-1ß and IL-6 in the tissues and serum of the diabetic rats. We conclude that CAMFs exerted apparent antidiabetic effects and demonstrated as a valuable candidate nutraceutical for insulin-resistant type 2 diabetes and its associated complications such as dyslipidemia, oxidative stress, and inflammation.

Anti-diabetic effects of Centratherum anthelminticum seeds methanolic fraction on pancreatic cells, ß-TC6 and its alleviating role in type 2 diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Seeds of Centratherum anthelminticum (Asteraceae) have been popularly used in Ayurvedic medicine to treat diabetes and skin disorders. Folk medicine from Rayalaseema (Andhra Pradesh, India) reported wide spread usage in diabetes. AIM OF THE STUDY: To investigate the hypoglycemic properties and mechanism of the methanolic fraction of C. anthelminticum seeds (CAMFs) on mouse ß-TC6 pancreatic cell line and streptozotocin (STZ)-induced diabetic rat models. MATERIALS AND METHODS: We investigated the crude methanolic fraction of C. anthelminticum seeds (CAMFs) on ß-TC6 cell line and confirmed its effects on type 1 and type 2 diabetic rats to understand its mechanism in managing diabetes mellitus. CAMFs were initially tested on ß-TC6 cells for cytotoxicity, 2-NBDG glucose uptake, insulin secretion and glucose transporter (GLUT-1, 2 and 4) protein expression. Furthermore, streptozotocin (STZ)-induced type 1 diabetic and STZ-nicotinamide-induced type 2 diabetic rats were intraperitoneally (i.p) injected or administered orally with CAMFs daily for 28 days. The effect of CAMFs on blood glucose and insulin levels was subsequently evaluated. RESULTS: In cell line studies, CAMFs showed non-cytotoxic effect on ß-TC6 cell proliferation compared to untreated control cells at 50 µg/ml. CAMFs increased glucose uptake and insulin secretion dose-dependently by up-regulating GLUT-2 and GLUT-4 expression in these cells. Further in vivo studies on streptozotocin induced diabetic rat models revealed that CAMFs significantly reduced hyperglycemia by augmenting insulin secretion in type 2 diabetic rats. However, CAMFs displayed less significant effects on type 1 diabetic rats. CONCLUSIONS: CAMFs demonstrated anti-diabetic potential on ß-TC6 cells and type 2 diabetic rat model, plausibly through enhancing glucose uptake and insulin secretion.

Bisphenol S in urine from the United States and seven Asian countries: occurrence and human exposures.

As concern regarding the toxic effects of bisphenol A (BPA) grows, BPA in many consumer products is gradually being replaced with compounds such as bisphenol S (BPS). Nevertheless, data on the occurrence of BPS in human specimens are limited. In this study, 315 urine samples, collected from the general populations in the United States, China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam, were analyzed for the presence of total BPS (free plus conjugated) concentrations by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). BPS was detected in 81% of the urine samples analyzed at concentrations ranging from below the limit of quantitation (LOQ; 0.02 ng/mL) to 21 ng/mL (geometric mean: 0.168 ng/mL). The urinary BPS concentration varied among countries, and the highest geometric mean concentration [1.18 ng/mLor 0.933 µg/g creatinine (Cre)] of BPS was found in urine samples from Japan, followed by the United States (0.299 ng/mL, 0.304 µg/g Cre), China (0.226 ng/mL, 0.223 µg/g Cre), Kuwait (0.172 ng/mL, 0.126 µg/g Cre), and Vietnam (0.160 ng/mL, 0.148 µg/g Cre). Median concentrations of BPS in urine samples from the Asian countries were 1 order of magnitude lower than the median concentrations reported earlier for BPA in the same set of samples, with the exception of samples from Japan. There were no significant differences in BPS concentrations between genders (male versus female), or among age groups (categorized as ≤ 19, 20-29, 30-39, 40-49, and ≥ 50 years), or races (Caucasian versus Asian). The daily intake (EDI) of BPS was estimated on the basis of urinary concentrations using a simple pharmacokinetic approach. The median EDI values of BPS in Japan, China, United States, Kuwait, Vietnam, Malaysia, India, and Korea were 1.67, 0.339, 0.316, 0.292, 0.217, 0.122, 0.084, and 0.023 µg/person, respectively. This is the first study to report the occurrence of BPS in human urine.

Urinary metabolic evaluation of stone formers-a Malaysian perspective.

OBJECTIVE: To investigate the urinary metabolic excretion pattern among local stone formers given the great differences in the intrinsic and extrinsic risk factors as well as the urinary metabolic excretions compared with other populations. METHODS: Thirty urinary stone formers out of an initial 62 recruited provided a complete 24-hour urine sample for metabolic evaluation. Student's t-test and Pearson correlation test were used for the statistical analysis. RESULTS: Urinary volume (1719 ± 712 vs 1215 ± 575, P < .05) and oxalate excretion (0.386 ± 0.111 vs 0.306 ± 0.104, P < .05) were significantly higher among stone formers than controls. Other commonly studied urinary parameters and urinary melamine did not differ significantly between the 2 groups. Similarly, the calcium/citrate ratio was unable to discriminate the stone formers from their controls. Hypocitraturia was the most prevalent urinary abnormality found in stone formers and low urinary citrate excretion was a general phenomenon in both stone formers and controls. Comparing within the stone formers cohort, the recurrent stone formers had a significantly higher urinary saturation and calcium excretion than their first-time stone former counterparts. CONCLUSION: Elevated urinary oxalate level was the most important urinary risk factor among the local stone formers. A low urinary citrate excretion appeared to be a general phenomenon among the studied cohorts.

Chloroform Fraction of Centratherum anthelminticum (L.) Seed Inhibits Tumor Necrosis Factor Alpha and Exhibits Pleotropic Bioactivities: Inhibitory Role in Human Tumor Cells.

We investigated the antioxidant potential, cytotoxic effect, and TNF-α inhibition activity with NF-κB activation response in a chloroform fraction of Centratherum anthelminticum seeds (CACF). The antioxidant property of CACF was evaluated with DPPH, ORAC, and FRAP assays, which demonstrated significant antioxidant activity. The cytotoxicity of CACF was tested using the MTT assay; CACF effective inhibitory concentrations (IC(50)) for A549, PC-3, MCF-7, and WRL-68 cells were 31.42 ± 5.4, 22.61 ± 1.7, 8.1 ± 0.9, and 54.93 ± 8.3 µg/mL, respectively. CACF effectively and dose-dependently inhibited TNF-α release, in vitro and in vivo. CACF inhibited TNF-α secretion in stimulated RAW264.7 macrophage supernatants with an IC(50) of 0.012 µg/mL, without affecting their viability; the highest dose tested reduced serum TNF-α by 61%. Acute toxicity testing in rats revealed that CACF was non-toxic at all doses tested. Matching the cytotoxic activity towards a mechanistic approach, CACF dose-dependently exhibited in vitro inhibitory effects against the activation of NF-κB translocation in MCF-7 cells. Preliminary phytochemical screening with GC/MS analysis detected 22 compounds in CACF, of which morpholinoethyl isothiocyanate was the most abundant (29.04%). The study reveals the potential of CACF in the treatment of breast cancer and in oxidative stress conditions with associated inflammatory responses.

Urinary bisphenol A concentrations and their implications for human exposure in several Asian countries.

Bisphenol A (BPA) is an industrial chemical used in the manufacture of polycarbonate plastics and epoxy resins. Due to the potential of this compound to disrupt normal endocrinal functions, concerns over human exposure to BPA have been raised. Although several studies have reported human exposure to BPA in Western nations, little is known about exposure in Asian countries. In this study, we determined total urinary BPA concentrations (free plus conjugated) in 296 urine samples (male/female: 153/143) collected from the general population in seven Asian countries, China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam, using high-performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). On the basis of urinary BPA concentrations, we estimated the total daily intake. The results indicated that BPA was detected in 94.3% of the samples analyzed, at concentrations ranging from <0.1 to 30.1 ng/mL. The geometric mean concentration of BPA for the entire sample set from seven countries was 1.20 ng/mL. The highest concentration of BPA was found in samples from Kuwait (median: 3.05 ng/mL, 2.45 µg/g creatinine), followed by Korea (2.17 ng/mL, 2.40 µg/g), India (1.71 ng/mL, 2.09 µg/g), Vietnam (1.18 ng/mL, 1.15 µg/g), China (1.10 ng/mL, 1.38 µg/g), Malaysia (1.06 ng/mL, 2.31 µg/g), and Japan (0.95 ng/mL, 0.58 µg/g). Among the five age groups studied (≤ 19, 20-29, 30-39, 40-49, and ≥ 50 years), the highest median concentration of BPA was found in urine samples from the age group of ≤ 19 years. There was no significant difference in BPA concentrations between genders (male and female) or domicile of residence (rural and urban). The estimated median daily intakes of BPA for the populations in Kuwait, Korea, India, China, Vietnam, Malaysia, and Japan were 5.19, 3.69, 2.90, 2.13, 2.01, 1.80, and 1.61 µg/day, respectively. The estimated daily intake of BPA in the seven Asian countries was significantly lower than the tolerable daily intake recommended by the U.S. Environmental Protection Agency. This is the first study to document the occurrence of and human exposure to BPA in several Asian countries.

Occurrence of phthalate metabolites in human urine from several Asian countries.

The occurrence of 14 phthalate metabolites was found in human urine samples collected from seven Asian countries: China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam. Phthalate metabolites were found in all samples, indicating widespread exposure of humans to phthalates in these Asian countries. The highest total (the sum of 14 phthalates) phthalate metabolite concentrations were found in samples collected from Kuwait (median: 1050 ng/mL), followed in decreasing order by samples from India (389 ng/mL), China (234 ng/mL), Vietnam (133 ng/mL), Japan (120 ng/mL), Korea (117 ng/mL), and Malaysia (94.9 ng/mL). The creatinine-adjusted median concentrations of total phthalates for urine samples from Kuwait, India, China, Vietnam, Japan, Korea, and Malaysia were 692, 506, 289, 119, 103, 104, and 169 µg/g creatinine, respectively. Monomethyl phthalate (mMP), monoethyl phthalate (mEP), mono (2-isobutyl phthalate) (miBP), mono-n-butyl phthalate (mBP), and metabolites of di-(2-ethylhexyl) phthalate (DEHP) were the dominant compounds, collectively accounting for >95% of the total concentrations in the samples from the seven countries. The profiles of urinary phthalate metabolite concentrations varied among the samples collected from the seven countries. Urine samples from Kuwait contained the highest concentrations of mEP (median: 391 ng/mL), mBP (94.1 ng/mL), and the metabolites of DEHP (202 ng/mL), whereas samples from China and Japan contained the highest concentrations of miBP (50.8 ng/mL) and mMP (17.5 ng/mL), respectively. mEP was the predominant metabolite in urine samples from India and Kuwait (accounting for 49% of the total), mBP and miBP were the predominant compounds in samples from China (52%), and DEHP metabolites were the predominant compounds in samples from Korea (46%) and Vietnam (52%). Based on the urinary concentrations of mEP, mBP, miBP, and DEHP metabolites of the samples from the seven Asian countries, we estimated daily intake rates of diethyl phthalate (DEP), dibutyl phthalate (DBP), and DEHP. The results indicated that people in the seven Asian countries are exposed to DEP, DBP, and DEHP at levels well below the reference doses (RfD) suggested as unsafe by the U.S. Environmental Protection Agency (EPA). The estimated exposure doses to DEHP in Kuwait, however, were above the RfD recommended by the EPA.

In vitro and in vivo anti-inflammatory activity of 17-O-acetylacuminolide through the inhibition of cytokines, NF-κB translocation and IKKß activity.

BACKGROUND AND PURPOSE: 17-O-acetylacuminolide (AA), a diterpenoid labdane, was isolated for the first time from the plant species Neouvaria foetida. The anti-inflammatory effects of this compound were studied both in vitro and in vivo. EXPERIMENTAL APPROACH: Plant extracts were initially tested against LPS-stimulated release of tumor necrosis factor alpha (TNF-α) from murine macrophages (RAW264.7 cells). Based on bioassay-guided fractionation, the active compound was identified as AA. AA was tested for its ability to reduce nitric oxide (NO) production, and the inducible nitric oxide synthase (iNOS) expression. The inhibition of a panel of inflammatory cytokines (TNF, IL-1ß, IL-6, KC, and GM-CSF) by AA was assessed at the expression and the mRNA levels. Moreover, the effect of AA on the translocation of the transcription factor nuclear factor kappa B (NF-κB) was evaluated in LPS-stimulated RAW264.7 cells and in TNF-stimulated L929 cells. Subsequently, AA was tested in the inhibitor of NF-κB kinase beta (IKKß) activity assay. Lastly, the anti-inflammatory activity of AA in vivo was evaluated by testing TNF production in LPS-stimulated Balb/c mice. KEY RESULTS: AA effectively inhibited TNF-α release with an IC(50) of 2.7 µg/mL. Moreover, AA significantly inhibited both NO production and iNOS expression. It significantly and dose-dependently inhibited TNF and IL-1ß proteins and mRNA expression; as well as IL-6 and KC proteins. Additionally, AA prevented the translocation of NF-κB in both cell lines; suggesting that it is acting at a post receptor level. This was confirmed by AA's ability to inhibit IKKß activity, a kinase responsible for activating NF-κB, hence providing an insight on AA's mechanism of action. Finally, AA significantly reduced TNF production in vivo. CONCLUSIONS AND IMPLICATIONS: This study presents the potential utilization of this compound, as a lead for the development of an anti-inflammatory drug.

Ellagic acid, phenolic acids, and flavonoids in Malaysian honey extracts demonstrate in vitro anti-inflammatory activity.

Natural honey has been used in traditional medicine of different cultures throughout the world. This study looked into the extraction of Malaysian honey and the evaluation of the anti-inflammatory activity of these extracts. It was hypothesized that honey extracts contain varying amounts of phenolic compounds and that they possess different in vitro anti-inflammatory activities. Honey extracts were analyzed using liquid chromatography-mass spectrometry to identify and compare phenolic compounds, whereas high-performance liquid chromatography was used for their quantification. Subsequently, honey methanol extract (HME) and honey ethyl acetate extract (HEAE) were tested in vitro for their effect on nitric oxide production in stimulated macrophages. The extracts were also tested for their effects on tumor necrosis factor-α (TNF) cytotoxicity in L929 cells. The major phenolics in the extracts were ellagic, gallic, and ferulic acids; myricetin; chlorogenic acid; and caffeic acid. Other compounds found in lower concentrations were hesperetin, p-coumaric acid, chrysin, quercetin, luteolin, and kaempferol. Ellagic acid was the most abundant of the phenolic compounds recorded, with mean concentrations of 3295.83 and 626.74 µg/100 g of honey in HME and HEAE, respectively. The median maximal effective concentrations for in vitro nitric oxide inhibition by HEAE and HME were calculated to be 37.5 and 271.7 µg/mL, respectively. The median maximal effective concentrations for protection from TNF cytotoxicity by HEAE and HME were 168.1 and 235.4 µg/mL, respectively. In conclusion, HEAE exhibited greater activity in vitro, whereas HME contained a higher concentration of phenolic compounds per 100 g of honey.

Twenty-four hour and spot urine metabolic evaluations: correlations versus agreements.

OBJECTIVES: To investigate the correlations and agreements between the solute/creatinine ratios from the 24-hour and early morning spot urine samples for metabolic evaluation in stone-formers given the various pitfalls with the 24-hour urinary metabolic evaluation in stone-formers. METHODS: 30 urinary stone-formers out of an initial 62 recruited provided a complete 24-hour urine and early morning spot urine samples for metabolic evaluation. Pearson correlation and Bland and Altman Test were used to assess the correlations and agreements. RESULTS: Significant correlations were established between the 24-hour urinary solute excretions and the corresponding early morning spot urine solute/creatinine ratios for calcium, magnesium, urate, potassium, oxalate, citrate, and the Differential Gibb's free energy value of calcium oxalate DG(CaOx) values. However, all these solute/creatinine measurements between the 24-hour and early morning spot urine samples were judged to be not within the acceptable limits based on the estimated "limit of agreement" by the Bland and Altman Test of Agreement. Diurnal circadian rhythm and postprandial excretion surge are thought to be responsible for the disagreements. CONCLUSIONS: Thus, the early morning spot urine is not suitable to be used interchangeably to replace the 24-hour urine collection in the evaluation of urinary metabolic abnormalities in stone-formers. A good correlation does not translate to an agreement between the 2 measurements.

Baicalein impairs vascular tone in normal rat aortas: role of superoxide anions.

Acute exposure to the flavonoid baicalein inhibited endothelium-dependent relaxation in physiological arteries, although the mechanisms are not fully understood. We investigated the effect of baicalein on vascular tone in Wistar-Kyoto (WKY) rat isolated aortic rings in the presence and absence of oxidative stress to further determine the underlying mechanisms. Exposure to baicalein (10 microM) completely abolished endothelium-dependent relaxation induced by acetylcholine and attenuated significantly the endothelium-independent relaxation induced by sodium nitroprusside. Baicalein, similar to Nomega-nitro-L-arginine methyl ester (L-NAME, 10 microM), potentiated significantly the contractile response of aortic rings to alpha1-adrenoceptor agonist phenylephrine. In the presence of L-NAME the baicalein effect on phenylphrine contraction or acetylcholine relaxation was unaltered, suggesting that these effects of baicalein are (like L-NAME effect) endothelial nitric oxide synthase (eNOS)/endothelium-derived nitric oxide-dependent. Inhibition of cyclooxygenase activity with indomethacin (10 microM) or scavenging of superoxide anions with superoxide dismutase (150 units/ml), but not scavenging of hydrogen peroxide with catalase (800 units/ml), enhanced significantly by an essentially similar extent the relaxation to acetylcholine in baicalein-pretreated aortic rings. Relaxant effect to acetylcholine was significantly attenuated in control aortic rings, but was completely abolished in baicalein-pretreated aortic rings in the presence of reduced form of beta-nicotinamide adenine di-nucleotide (beta-NADH, 300 microM). Baicalein blocked beta-NADH (300 microM)-induced transient contractions, suggesting that baicalein may have inhibited activity of NADH/NADPH-oxidase. Baicalein did not alter the failure of acetylcholine to induce relaxation in the presence of pyrogallol (300 microM). In summary, acute exposure to baicalein impairs eNOS/endothelium-derived nitric oxide-mediated vascular tone in rat aortas through the inhibition of endothelium-derived nitric oxide bioavailability coupled to reduced bioactivity of endothelium-derived nitric oxide and to cyclooxygenase-mediated release of superoxide anions.

Determination of sulfonamides in selected Malaysian swine wastewater by high-performance liquid chromatography.

An analytical HPLC method for the simultaneous determination of eight sulfonamides in swine wastewater was developed. The samples were collected from three states in Malaysia. Sample clean up was carried out by employing solid-phase extraction using a 60 mg Oasis HLB (Waters) cartridge with 3 ml reservoir. The HPLC column used was Supelcosil C18 (250 mm x 4.6mm I.D.) and elution was carried out using gradient mode. The mobile phases used were acetonitrile and 0.5% acetic acid in purified water. Antibiotics were detected using UV absorbance at 272 nm. Recoveries obtained for sulphanilamide ranged from 31.9+/-5.1% to 36.2+/-1.0%, while recoveries for other sulfa drugs studied were from 91.9+/-5.0% to 106.0+/-1.1%. The limit of quantitation (LOQ) for sulfamerazine, sulfamethazine and sulfamethoxypyridazine was 7.5 ng/L, while the LOQ for the other studied antibiotics was 5.0 ng/L. The method was used to analyse sulfonamides in wastewater collected from selected Malaysian swine facilities.

Analysis of endosulfan and its metabolites in rat plasma and selected tissue samples by gas chromatography-mass spectrometry.

A method has been developed for the determination of trace levels of alpha-endosulfan, beta-endosulfan, endosulfan sulfate, and endosulfan diol in rat plasma and tissue samples. Endosulfan and its metabolites in the plasma samples were extracted with solid-phase extraction Chromabond-end-capped C18 cartridges and analyzed by a Shimadzu QP-5050A gas chromatograph-mass spectrometer (GCMS) with quadrupole detector in selected-ion-monitoring mode. The analysis of endosulfan and its metabolites in liver and kidney samples involved solvent extraction, Florisil solid-phase-extraction cleanup, and quantitation by GCMS. Recovery experiments for the plasma and tissue samples were conducted over concentration ranges of 10-100 ng mL(-1) and 100-1000 ng mL(-1), respectively. The method was applied to the analysis of trace levels of endosulfan and its metabolites in plasma and tissue samples collected from an animal study. Trace levels of alpha-endosulfan and beta-endosulfan in the ranges of undetectable to 3.11 microg g(-1) and undetectable to 1.19 microg g(-1), respectively, were detected in the kidney samples, whereas trace levels of endosulfan sulfate in the range of 0.02-0.22 microg g(-1) were detected in the liver samples of rats. Neither endosulfan nor its metabolites was detected in any of the plasma samples.

Perfluorooctanesulfonate and related fluorochemicals in human blood from several countries.

Perfluorooctanesulfonyl fluoride based compounds have been used in a wide variety of consumer products, such as carpets, upholstery, and textiles. These compounds degrade to perfluorooctanesulfonate (PFOS), a persistent metabolite that accumulates in tissues of humans and wildlife. Previous studies have reported the occurrence of PFOS, perfluorohexanesulfonate (PFHxS), perfluorooctanoate (PFOA), and perfluorooctanesulfonamide (PFOSA) in human sera collected from the United States. In this study, concentrations of PFOS, PFHxS, PFOA, and PFOSA were measured in 473 human blood/serum/plasma samples collected from the United States, Colombia, Brazil, Belgium, Italy, Poland, India, Malaysia, and Korea. Among the four perfluorochemicals measured, PFOS was the predominant compound found in blood. Concentrations of PFOS were the highest in the samples collected from the United States and Poland (>30 ng/mL); moderate in Korea, Belgium, Malaysia, Brazil, Italy, and Colombia (3 to 29 ng/mL); and lowest in India (<3 ng/mL). PFOA was the next most abundant perfluorochemical in blood samples, although the frequency of occurrence of this compound was relatively low. No age- or gender-related differences in the concentrations of PFOS and PFOA were found in serum samples. The degree of association between the concentrations of four perfluorochemicals varied, depending on the origin of the samples. These results suggested the existence of sources with varying levels and compositions of perfluorochemicals, and differences in exposure patterns to these chemicals, in various countries. In addition to the four target fluorochemicals measured, qualitative analysis of selected blood samples showed the presence of other perfluorochemicals such as perfluorodecanesulfonate (PFDS), perfluoroheptanoic acid (PFHpA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA), and perfluoroundecanoic acid (PFUnDA) in serum samples, at concentrations approximately 5- to 10-fold lower than the concentration of PFOS. Further studies should focus on identifying sources and pathways of human exposure to perfluorochemicals.

Assessment of pubertal development in juvenile male rats after sub-acute exposure to bisphenol A and nonylphenol.

The effects of bisphenol A and nonylphenol on pubertal development in the intact juvenile/peripubertal male Sprague-Dawley rats was observed in this study from PND23-52/53. Two groups of rats were administered orally with either 100 mg/kg body weight of nonylphenol or bisphenol A. Another group of rats were administered orally with a mixture of 100 mg/kg body weight of nonylphenol and bisphenol A. Control group was administered with the vehicle of Tween-80 with corn oil (1:9 v/v). Observations made in this study included growth, age at preputial separation, thyroid, liver, testis and kidney weight and histology, epididymal and seminal vesicle plus coagulation gland weight. Nonylphenol and bisphenol A have been observed to cause delay in puberty onset as well as testicular damage in the treatment groups when compared to the control; spermatogenesis was affected in most treated rats. Bisphenol A also caused the enlargement of the kidney and hydronephrosis. Administration of nonylphenol and bisphenol A as a mixture has caused less than additive effects.