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Kidney International Dec 2000Myeloperoxidase-catalyzed oxidative pathways have recently been identified as an important cause of oxidant stress in uremia and hemodialysis (HD), and can lead to...
BACKGROUND
Myeloperoxidase-catalyzed oxidative pathways have recently been identified as an important cause of oxidant stress in uremia and hemodialysis (HD), and can lead to plasma protein oxidation. We have examined patterns of plasma protein oxidation in vitro in response to hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). We measured thiol oxidation, amine oxidation, and carbonyl concentrations in patients on chronic maintenance HD compared with patients with chronic renal failure (CRF) and normal volunteers. We have also examined the effect of the dialysis procedure on plasma protein oxidation using biocompatible and bioincompatible membranes.
METHODS
Plasma proteins were assayed for the level of free thiol groups using spectrophotometry, protein-associated carbonyl groups by enzyme-linked immunosorbent assay, and oxidation of free amine groups using a fluorescent spectrophotometer.
RESULTS
In vitro experiments demonstrate HOCl oxidation of thiol groups and increased carbonyl formation. In vivo, there are significant differences in plasma-free thiol groups between normal volunteers (279 +/- 12 micromol/L), CRF patients (202 +/- 20 micromol/L, P = 0.005) and HD patients (178 +/- 18 micromol/L, P = 0.0001). There are also significant differences in plasma protein carbonyl groups between normal volunteers (0.76 +/- 0.51 micromol/L), CRF patients (13.73 +/- 4.45 micromol/L, P = 0.015), and HD patients (16.95 +/- 2.62 micromol/L, P = 0.0001). There are no significant differences in amine group oxidation. HD with both biocompatible and bioincompatible membranes restored plasma protein thiol groups to normal levels, while minimally affecting plasma protein carbonyl expression.
CONCLUSIONS
First, both CRF and HD patients have increased plasma protein oxidation manifested by oxidation of thiol groups and formation of carbonyl groups. Second, HD with biocompatible and bioincompatible membranes restored plasma protein thiol groups to normal levels. Third, these experiments suggest that there is a dialyzable low molecular weight toxin found in uremia that is responsible for plasma protein oxidation.
Topics: Amines; Biocompatible Materials; Blood Proteins; Humans; Hydrogen Peroxide; Hypochlorous Acid; In Vitro Techniques; Kidney Failure, Chronic; Membranes, Artificial; Oxidants; Oxidation-Reduction; Oxidative Stress; Phagocytes; Renal Dialysis; Sulfhydryl Compounds; Uremia
PubMed: 11115093
DOI: 10.1046/j.1523-1755.2000.00443.x -
Journal of Zhejiang University.... Oct 2005A hydroponic experiment carried out to study the effect of five Cd levels on growth and photosynthesis of two tomato cultivars showed that the addition of 0.1 micromol/L...
A hydroponic experiment carried out to study the effect of five Cd levels on growth and photosynthesis of two tomato cultivars showed that the addition of 0.1 micromol/L Cd induced a slight increase in plant height of Hezuo 903 and the SPAD (the Soil-Plant Analyses Development) value of the 2 cultivars. However, at higher Cd levels, i.e., 1 and 10 micromol/L, root length and volume, plant height, and SPAD value were all significantly reduced. On an average of the 2 cultivars, exposure to 1 and 10 micromol/L Cd for 33 d reduced plant height by 18.9% and 46.4% and SPAD value by 11.2% and 31.6%, compared with control, respectively. Similarly, root length was reduced by 41.1% and 25.8% and root volume by 45.2% and 63.7%, respectively. The addition of Cd in the growth medium also had significant deleterious effect on net photosynthetic rate (Pn) and intracellular CO(2) concentration (Ci), with Pn being reduced by 27.2% and 62.1% at 1 micromol/L and 10 micromol/L Cd treatments compared to the control, respectively, while Ci increased correspondingly by 28.4% and 39.3%.
Topics: Cadmium; Solanum lycopersicum; Photosynthesis; Plant Leaves; Plant Roots; Seedlings
PubMed: 16187410
DOI: 10.1631/jzus.2005.B0974 -
German Medical Science : GMS E-journal Jun 2007Low antioxidant system may contribute to the severity of neonatal hyperbilirubinemia. The aim of this research was to explore the relationship between plasma vitamin E...
OBJECTIVE
Low antioxidant system may contribute to the severity of neonatal hyperbilirubinemia. The aim of this research was to explore the relationship between plasma vitamin E and C levels and the severity of hyperbilirubinemia in full-term neonates with normal glucose 6-phosphate dehydrogenase (G6PD) activities.
METHODS
A total of 130 full-term healthy live birth neonates of healthy mothers with normal G6PD activity were included in this study. In addition to routine blood analysis, plasma total bilirubin, vitamin E and C levels and G6PD activity were measured on the first day of life. None of the neonates was ABO incompatible or anemic.
RESULTS
Neonates who did not develop hyperbilirubinemia (n=119) had a mean plasma bilirubin level of 65+/-24 micromol/l (median 58.1), while neonates who developed significant hyperbilirubinemia (n=11) had a mean plasma bilirubin level of 238+/-56 micromol/l (median 246.2) on the first day of life. Mean plasma vitamin C levels of neonates who developed hyperbilirubinemia were significantly lower than those who did not develop hyperbilirubinemia (87+/-22 micromol/l (median 89.4) vs. 132+/-36 micromol/l (median 127.7), respectively, P=0.0001). Similar results were observed for plasma vitamin E levels in neonates who did or did not develop hyperbilirubinemia (7.5+/-2 micromol/l (median 6.3) vs. 10.4+/-5 micromol/l (median 9.1), respectively, P=0.001). Hemoglobin and hematocrit were significantly lower in neonates who developed hyperbilirubinemia (P=0.0002 and P=0.0003, respectively), although gestational age and birth weight for the two groups showed no significant difference.
CONCLUSION
The results of the present work indicate that low level of plasma vitamins C and E are associated with significant hyperbilirubinemia in full-term neonates.
PubMed: 19675711
DOI: No ID Found -
Archives of Disease in Childhood. Fetal... Nov 2007To measure the zinc, copper, selenium and manganese blood levels in a cohort of 68 preterm infants, and to establish any associations with growth and/or dietary intake.
OBJECTIVE
To measure the zinc, copper, selenium and manganese blood levels in a cohort of 68 preterm infants, and to establish any associations with growth and/or dietary intake.
DESIGN
Blood samples were collected at an infant's expected date of delivery (term) and 6 months later. Serum zinc, plasma copper and whole blood manganese were analysed by atomic absorption spectrometry, plasma and red cell selenium were determined by mass spectrometry. Growth and dietary intake determinations have been previously published.
SETTING
Hampshire, England.
RESULTS
Mean (SD) birth weight of the infants was 1.47 (0.434) kg and mean gestation was 31.4 (2.9) weeks. Mean blood levels at term and 6 months were: serum zinc 12.0 (2.6) micromol/l and 13.8 (2.5) micromol/l; plasma copper 10.1 (2.6) micromol/l and 19.2 (3.6) micromol/l; plasma selenium 0.49 (0.15) micromol/l and 0.72 (0.14) micromol/l; red blood cell selenium 1.68 (0.40) micromol/l and 1.33 (0.19) micromol/l; and blood manganese 320 (189) nmol/l and 211 (68) nmol/l, respectively. There were no significant associations between levels of zinc and copper and dietary intakes of those nutrients at either age (dietary intakes of selenium and manganese were not determined). Only copper levels at term were significantly associated (r = 0.31; p = 0.05) with a growth parameter (head circumference).
CONCLUSION
These results provide new information about trace element status in this vulnerable population.
Topics: Child Development; Copper; Diet; Female; Humans; Infant Nutritional Physiological Phenomena; Infant, Newborn; Infant, Premature; Longitudinal Studies; Male; Manganese; Selenium; Trace Elements; United Kingdom; Zinc
PubMed: 17468128
DOI: 10.1136/adc.2006.107755 -
The Journal of Nutrition Jun 2007Hyperphenylalaninemia (HPA) is the most frequently inherited disorder of amino acid metabolism (prevalence 1:10,000). In France, a nationwide neonatal screening was...
Hyperphenylalaninemia (HPA) is the most frequently inherited disorder of amino acid metabolism (prevalence 1:10,000). In France, a nationwide neonatal screening was organized in 1978 to control its efficacy and patient follow-up. Phenylketonuria (PKU) was diagnosed in 81.6% of screened patients, the remaining affected with either non-PKU HPA (17.2%) or with cofactor deficiency (1.1%). French guidelines were established to specify the minimal diagnosis procedures and optimal treatment of patients. A low-phenylalanine diet must be started within the first days of life for all newborns whose blood phenylalanine levels are above 10 mg/dL (600 micromol/L). The dietary control must keep the phenylalanine levels between 2 and 5 mg/dL (120 and 300 micromol/L) until 10 y of age. Thereafter, a progressive and controlled relaxation of the diet is allowed, keeping levels below 15 mg/dL until the end of adolescence and below 20 mg/dL (1200 micromol/L) in adulthood. A lifelong follow-up is recommended for PKU women to prevent for maternal PKU.
Topics: Child; Child, Preschool; Diet Therapy; Humans; Monitoring, Physiologic; Phenylalanine; Phenylketonurias
PubMed: 17513425
DOI: 10.1093/jn/137.6.1561S -
Kidney International Jan 2004Harmful uremic toxins, such as indoxyl sulfate (IS), 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), indoleacetate (IA), and hippurate (HA), accumulate to a high...
BACKGROUND
Harmful uremic toxins, such as indoxyl sulfate (IS), 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), indoleacetate (IA), and hippurate (HA), accumulate to a high degree in uremic plasma. IS has been shown to be a substrate of rat organic anion transporter 1 (rOat1) and rOat3. However, the contribution of rOat1 and rOat3 to the renal uptake transport process of IS and other uremic toxins in the kidney remains unknown.
METHODS
The cellular uptake of uremic toxins was determined using stable transfectants of rOat1/hOAT1 and rOat3/hOAT3 cells. Also, the uptake of uremic toxins by rat kidney slices was characterized to evaluate the contribution of rOat1 and rOat3 to the total uptake by kidney slices using inhibitors of rOat1 (p-aminohippurate) and rOat3 (pravastatin and benzylpenicillin).
RESULTS
Saturable uptake of IS, CMPF, IA, and HA by rOat1 was observed with Km values of 18, 154, 47, and 28 micromol/L, respectively, whereas significant uptake of IS and CMPF, but not of IA or HA, was observed in rOat3-expressing cells with Km values of 174 and 11 micromol/L, respectively. Similar parameters were obtained for human OAT1 and OAT3. Kinetic analysis of the IS uptake by kidney slices revealed involvement of two saturable components with Km1 (24 micromol/L) and Km2 (196 micromol/L) values that were comparable with those of rOat1 and rOat3. The Km value of CMPF uptake by kidney slices (22 micromol/L) was comparable with that of rOat3, while the corresponding values of IA and HA (42 and 33 micromol/L, respectively) were similar to those of rOat1. PAH preferentially inhibited the uptake of IA and HA by kidney slices, while pravastatin and benzylpenicillin preferentially inhibited the uptake of CMPF. The effect of these inhibitors on the uptake of IS by kidney slices was partial.
CONCLUSIONS
rOat1/hOAT1 and rOat3/hOAT3 play major roles in the renal uptake of uremic toxins on the basolateral membrane of the proximal tubules. Both OAT1 and OAT3 contribute almost equally to the renal uptake of IS. OAT3 mainly accounts for CMPF uptake by the kidney, while OAT1 mainly accounts for IA and HA uptake.
Topics: Animals; DNA, Complementary; GABA Modulators; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Kidney Tubules, Proximal; LLC-PK1 Cells; Male; Organ Culture Techniques; Organic Anion Transport Protein 1; Organic Anion Transporters, Sodium-Independent; Penicillin G; Pravastatin; Rats; Rats, Sprague-Dawley; Swine; Toxins, Biological; Transfection; Uremia; p-Aminohippuric Acid
PubMed: 14675047
DOI: 10.1111/j.1523-1755.2004.00354.x -
Radiology Oct 2005To investigate prospectively the feasibility of using optical tomography with ultrasonographic (US) localization to differentiate malignant from benign breast masses and...
PURPOSE
To investigate prospectively the feasibility of using optical tomography with ultrasonographic (US) localization to differentiate malignant from benign breast masses and to compare optical tomography with color Doppler US.
MATERIALS AND METHODS
The study was approved by the local internal review board committee and by the Human Subjects Research Review Board of Army Medical Research and Materiel Command. Signed informed consent was obtained, and the study was HIPAA compliant. Between May 2003 and March 2004, 65 consecutive women (mean age, 51 years; age range, 24-80 years) with 81 breast lesions underwent US-guided biopsy and were scanned with a combined imager. The hand-held probe, which consisted of a centrally located US transducer surrounded by near-infrared sensors, was used to simultaneously acquire coregistered US images and optical data. The lesion location obtained at US was used to guide optical imaging reconstruction. Light absorption was measured at two wavelengths. From these measurements, tumor angiogenesis was assessed on the basis of calculated total hemoglobin concentration. A Student t distribution was used to calculate the statistical significance of mean maximum and mean average hemoglobin concentrations obtained in malignant and benign lesion groups, and P < .001 was considered to indicate a statistically significant difference.
RESULTS
Biopsy results revealed eight early stage invasive carcinomas (malignant group) and 73 benign lesions (benign group). The mean maximum and mean average hemoglobin concentrations in the malignant group were 122 micromol/L +/- 26.8 (+/- standard deviation) and 88 micromol/L +/- 24.5, respectively. The mean maximum and mean average hemoglobin concentrations in the benign group were 55 micromol/L +/- 24.8 and 38 micromol/L +/- 17.4, respectively. Both the maximum and average total hemoglobin concentrations were significantly higher in the malignant group compared with the benign group (P < .001). When a maximum hemoglobin concentration of 95 micromol/L was used as the threshold value, the sensitivity, specificity, positive predictive value, and negative predictive value of optical tomography were 100%, 96%, 73%, and 100%, respectively, and the sensitivity, specificity, positive predictive value, and negative predictive value of color Doppler US were 63%, 69%, 19%, and 94%, respectively.
CONCLUSION
Findings indicate that optical tomography with US localization is feasible for differentiating benign and early stage malignant breast lesions.
Topics: Adult; Aged; Aged, 80 and over; Breast Diseases; Breast Neoplasms; Diagnosis, Differential; Feasibility Studies; Female; Hemoglobins; Humans; Middle Aged; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Tomography, Optical; Ultrasonography, Doppler, Color
PubMed: 16183924
DOI: 10.1148/radiol.2371041236 -
World Journal of Gastroenterology Sep 2005To explore the effect of six bile salts, including glycocholate (GC), glycochenodeoxycholate (GCDC), glycodeoxycholate (GDC), taurocholate (TC), taurochenodeoxycholate...
AIM
To explore the effect of six bile salts, including glycocholate (GC), glycochenodeoxycholate (GCDC), glycodeoxycholate (GDC), taurocholate (TC), taurochenodeoxycholate (TCDC), taurodeoxycholate (TDC), and two bile acids including cholic acid (CA) and deoxycholic acid (DCA) on esophageal cancer Eca109 cell line.
METHODS
Eca109 cells were exposed to six bile salts, two bile acids and the mixed bile salts at different concentrations for 24-72 h. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to detect the cell proliferation. Apoptotic morphology was observed by phase-contrast video microscopy and deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Sub-G1 DNA fragmentations and early apoptosis cells were assayed by flow cytometry (FCM) with propidium iodide (PI) staining and annexin V-FITC conjugated with PI staining. Apoptosis DNA ladders on agarose were observed. Activation of caspase-3 was assayed by FCM with FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody and expressions of Bcl-2 and Bax proteins were examined immunocytochemically in 500 micromol/L-TC-induced apoptosis cells.
RESULTS
Five bile salts except for GC, and two bile acids and the mixed bile salts could initiate growth inhibition of Eca109 cells in a dose- and time-dependent manner. TUNEL, FCM, and DNA ladder assays all demonstrated apoptosis induced by bile salts and bile acids at 500 micromol/L, except for GC. Early apoptosis cell percentages in Eca109 cells treated with GCDC, GDC, TC, TCDC, TDC, CA at 500 micromol/L for 12 h, DCA at 500 micromol/L for 6 h, and mixed bile salts at 1000 micromol/L for 12 h were 7.5%, 8.7%, 14.8%, 8.9%, 7.8%, 9.3%, 22.6% and 12.5%, respectively, all were significantly higher than that in control (1.9%). About 22% of the cell population treated with TC at 500 micromol/L for 24 h had detectable active caspase-3, and were higher than that in the control (1%). Immunocytochemical assay suggested that TC down-regulated Bcl-2 protein level and up-regulated Bax protein level.
CONCLUSION
GCDC, GDC, TC, TCDC, TDC, CA and DCA, except for GC, can inhibit growth and induce apoptosis of esophageal cancer Eca109 cells. Activation of caspase-3, decreased Bcl-2 protein and increased Bax protein are involved in TC-induced apoptosis of Eca109 cells.
Topics: Apoptosis; Bile Acids and Salts; Caspase 3; Caspases; Cell Division; Cell Line, Tumor; Enzyme Activation; Esophageal Neoplasms; Humans; Proto-Oncogene Proteins c-bcl-2
PubMed: 16127738
DOI: 10.3748/wjg.v11.i33.5109 -
Journal of the American College of... Jan 2007We investigated whether lipopolysaccharide (LPS), a proximate cause of inflammation, activates calcineurin in cardiac myocytes and if calcineurin regulates apoptosis in...
OBJECTIVES
We investigated whether lipopolysaccharide (LPS), a proximate cause of inflammation, activates calcineurin in cardiac myocytes and if calcineurin regulates apoptosis in this setting.
BACKGROUND
Calcineurin regulates myocardial growth and hypertrophy, but its role in inflammation is unknown. Calcineurin has proapoptotic or antiapoptotic effects depending on the stimuli.
METHODS
Calcineurin activity was measured in left ventricular myocytes from adult Sprague Dawley rats. Cardiac apoptosis was measured by terminal deoxy-nucleotidyl transferase-mediated dUTP nick end-labeling staining and caspase-3 activity after in vitro and in vivo exposure to LPS.
RESULTS
Lipopolysaccharide increased calcineurin activity in myocytes over 1 to 24 h (t 1/2 = 4.8 h) with an EC(50) of 0.80 ng/ml LPS (p < 0.05, n = 4). The LPS (10 ng/ml) effects were mimicked by angiotensin II (Ang II) (100 nmol/l); both increased calcineurin activity and induced apoptosis without additive effects (p < 0.05, n = 5 to 9). Lipopolysaccharide and/or Ang II effects were prevented by 1 h pre-treatment with an Ang II type 1 receptor blocker (losartan, 1 micromol/l), calcineurin inhibitor (cyclosporin A, 0.5 micromol/l), calcium chelator (1,2-Bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl) ester, 0.1 micromol/l), or by inhibiting sarcoplasmic reticulum (SR) calcium (Ca)-ATPase (thapsigargin, 1 micromol/l) or SR calcium release channel (ryanodine, 1 micromol/l). Left ventricular apoptosis increased from 4 to 24 h after LPS (1 mg/kg intravenously) in vivo, but not in rats pre-treated with cyclosporin A (20 mg/kg/day subcutaneously) for 3 days (p < 0.05, n = 5).
CONCLUSIONS
In cardiac myocytes, LPS activates calcineurin in association with apoptosis by Ang II and SR calcium-dependent mechanisms. This expands the paradigm for cardiac calcineurin to be activated by low levels of LPS in inflammation and chronic conditions (e.g., infections, smoking, and heart failure).
Topics: Analysis of Variance; Animals; Apoptosis; Calcineurin; Heart Ventricles; Lipopolysaccharides; Myocytes, Cardiac; Rats; Rats, Sprague-Dawley
PubMed: 17258096
DOI: 10.1016/j.jacc.2006.10.043 -
Journal of Zhejiang University.... Sep 2009To investigate the effects of ursolic acid on the proliferation and apoptosis of human HT-29 colon cancer cells.
OBJECTIVE
To investigate the effects of ursolic acid on the proliferation and apoptosis of human HT-29 colon cancer cells.
METHODS
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays were performed to evaluate the effects of ursolic acid on the growth and apoptosis of HT-29 cells. Western blot analysis was applied to investigate the inhibitory effects of ursolic acid on the phosphorylation of the epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK), and the activity of B cell leukemia-2 (Bcl-2), B cell leukemia-xL (Bcl-xL), caspase-3, and caspase-9.
RESULTS
Ursolic acid inhibited the growth of HT-29 cells in dose- and time-dependent manners. The median inhibition concentration (IC50) values for 24, 48, and 72 h treatment were 26, 20, and 18 micromol/L, respectively. The apoptotic rates of 10, 20, and 40 micromol/L ursolic acid treatments for 24 h were 5.74%, 14.49%, and 33.05%, and for 48 h were 9%, 21.39%, and 40.49%, respectively. Ursolic acid suppressed the phosphorylation of EGFR, ERK1/2, p38 MAPK, and JNK, which is well correlated with its growth inhibitory effect. 10, 20, and 40 micromol/L ursolic acid significantly inhibited the proliferation of EGF-stimulated HT-29 cells (P<0.05). Cell proliferation was most significantly inhibited when treated with 10 and 20 micromol/L ursolic acid combined with 200 nmol/L AG 1478 or 10 micromol/L U0126 (P<0.01). Besides, it also down-regulated the expression of Bcl-2 and Bcl-xL and activated caspase-3 and caspase-9.
CONCLUSION
Ursolic acid induces apoptosis in HT-29 cells by suppressing the EGFR/MAPK pathway, suggesting that it may be a potent agent for the treatment of colorectal cancer.
Topics: Apoptosis; Dose-Response Relationship, Drug; ErbB Receptors; HT29 Cells; Humans; MAP Kinase Signaling System; Triterpenes; Ursolic Acid
PubMed: 19735099
DOI: 10.1631/jzus.B0920149