Oshra Saphier

The reduction of a nitroxide spin label as a probe of human blood antioxidant properties.

The kinetics of reduction of the radical R ”, 5-dimethylaminonaphthalene-1-sulfonyl-4-amino-2,2,6,6-tetramethyl-1-piperidine-oxyl, by blood and its components were studied using the EPR technique. The results demonstrate that R ” is adsorbed to the outer surface of the membrane and does not penetrate into the erythrocytes. A series of control experiments in PBS demonstrate that ascorbate is the only natural reducing agent that reacts with R ” . The observed first order rate of disappearance of the nitroxide radical, k , is: k blood > k eryth > k plasma and k blood ; k eryth + k plasma . The results demonstrate that: The erythrocytes catalyze the reduction of R ” by ascorbate. The rate of reduction of the radical is high though it does not penetrate the cells. In human erythrocytes there is an efficient electron transfer route through the cell membrane. The study points out that R ” is a suitable spin label for measuring the reduction kinetics and antioxidant capacity in blood as expressed by reduction by ascorbate.

Effect of albumin on the kinetics of ascorbate oxidation

The fluorescence intensity of the fluorophore in dansyl piperidine-nitroxide is intramolecularly quenched by the nitroxyl fragment. Therefore, the oxidation of ascorbic acid by the fluorophore-nitroxide (FN) probe can be monitored by two independent methods: steady-state fluorescence and electron paramagnetic resonance. Bovine serum albumin (BSA) affects the rate of this reaction. The influence of BSA on the rate is attributed to the adsorption of both ascorbate and the probe to BSA. Adsorption of ascorbate to BSA is confirmed by NMR relaxation experiments. The spatial distribution of the molecules on the BSA surface changes the availability of ascorbate and FN to each other. The results also point out that, in the presence of BSA, the autoxidation of ascorbate is significantly slowed down. The effect is studied at different pH values and explained in terms of the electrostatic interaction between the ascorbate anion and the BSA molecule.

Trace element concentrations in follicular fluid of small follicles differ from those in blood serum, and may represent long-term exposure

OBJECTIVE To determine the levels of elements in follicular fluid (FF) of patients undergoing IVF and evaluate the relationship between the concentration of elements in FF, follicular volume, and blood. DESIGN Prospective blinded study. SETTING University-based IVF center. PATIENT(S) Follicular fluid/blood samples from 6/3 patients, respectively, undergoing IVF. INTERVENTION(S) Single follicular aspirations of 33 follicles were performed. Blood samples ( approximately 5 mL) were drawn at the time of oocyte retrieval from 3/6 patients only. The concentrations 26 elements were measured by inductively coupled plasma mass spectroscopy. MAIN OUTCOME MEASURE(S) Trace elements concentrations in follicular fluid and blood. RESULT(S) [1] Calcium and magnesium were the most abundant, followed by Cu, Zn, Fe, Cr, Rb. The elements V, Sr, Se, B, As, Pb, Al, Mo, Mn, and Cs were found in trace amounts. The elements Li, Be, Ag, Cd, Ba, Ti, Bi, U were not detected. [2] Element concentrations in small follicles frequently differed from those of large follicles. [3] Element concentrations in large follicles more closely resembled those in blood. CONCLUSION(S) Concentrations of elements in FF of small follicles can differ from those of large follicles in the same woman and from those of blood serum. When follicles grow they become filled with fluid of an elemental composition similar to blood. Concentrations of elements in small follicles may represent longer term element exposure, whereas those of growing follicles represents the coincident blood concentrations.

Elements in maternal blood and amniotic fluid determined by ICP-MS

Abstract Objective: Knowledge about levels of toxic and non-toxic elements in amniotic fluid is limited. The aims of this study were: (1) to measure levels of trace elements Cu, Fe, Zn, B, Sr and Co in amniotic fluid and maternal serum during second trimester of pregnancy; and (2) to determine what correlations exists between elements levels in amniotic fluid and maternal serum. Methods: The levels of, iron, copper, zinc, cobalt, strontium and boron were measured in blood and amniotic fluid during genetic amniocentesis using inductively coupled plasma mass spectrometry (ICP-MS). Results: Concentrations of the elements: Fe, Cu, Zn, Co, Sr and B in amniotic fluid were significantly lower than in maternal blood. For iron, zinc, cobalt, strontium and boron there was a linear correlation between levels in amniotic fluid and maternal serum. Conclusions: The concentration of trace elements in amniotic fluid was found to be lower than maternal serum and linearly correlated to its level.

Fatty acid composition of breastmilk of Israeli mothers

We conducted this study to determine the fatty acid composition of breastmilk of Israeli women and compare it with baby milk substitutes. Samples of mature breast milk, from 29 lactating Israeli Jewish mothers were collected during feedings. Total milk lipids extracts were transmethylated and analyzed by using an improved gas-chromatographic method. About 72% of the total fatty acids in the investigated breast milk comprised oleic (18:1c; 31±4%), palmitic (16:0; 21±4%), and linoleic (18:2n-6; 20±4%) acids. Total saturated fatty acids represented 42±7% of total fatty acids. The monounsaturated fatty acids content was 33±5%, of which 94% was oleic acid, and the polyunsaturated fatty acids content was about 24±4%, of which 85% was linoleic acid. The α-linolenic acid level found in this study, 2.0±0.6%, was higher than the range of values reported for the world population (0.10–1.4%). The main fatty acids composition of the milk substitutes has very similar composition to the breast milk. Docosahexaenoic acid levels are particularly low among the population of Jewish nursing mothers in relation to the milk substitutes, containing docosahexaenoic acid in their formulations.

Labor Augmentation with Oxytocin Decreases Glutathione Level

Objective. To compare oxidative stress following spontaneous vaginal delivery with that induced by Oxytocin augmented delivery. Methods. 98 women recruited prior to labor. 57 delivered spontaneously, while 41 received Oxytocin for augmentation of labor. Complicated deliveries and high-risk pregnancies were excluded. Informed consent was documented. Arterial cord blood gases, levels of Hematocrit, Hemoglobin, and Bilirubin were studied. Glutathione (GSH) concentration was measured by a spectroscopic method. Plasma and red blood cell (RBC) levels of Malondialdehyde indicated lipid peroxidation. RBC uptake of phenol red denoted cell penetrability. SPSS data analysis was used. Results. Cord blood GSH was significantly lower in the Oxytocin group (2.3 ± 0.55 mM versus 2.55 ± 0.55 mM, P = .01). No differences were found in plasma or RBC levels of MDA or in uptake of Phenol red between the groups. Conclusion. Lower GSH levels following Oxytocin augmentation indicate an oxidative stress, though selected measures of oxidative stress demonstrate no cell damage.

Role of Radicals in the Lipid Peroxidation Products of Commercial Infant Milk Formula

Four commercial brands of infant milk formula were investigated, and the amount of shelf lipid peroxidation was determined by measuring malondialdehyde (MDA) or, more exactly, thiobarbituric acid reactive substance (TBARS) levels, which are the end products of lipid peroxidation. TBARS level, indicated by MDA concentration, was higher in the vegetarian brands. The vegetarian brands are, as expected, more prone to oxidation than dairy brands, as they contain more unsaturated fats. The introduction of formate anion diminishes the peroxide amounts initially present in the milk samples as well as those induced by radiation-induced oxidation.

Does mode of delivery affect neonate oxidative stress in parturition? Review of literature

PurposeThe production of reactive oxygen substances plays an important regulatory role in many physiologic reproductive processes. Excessive production may lead to oxidative stress (OS), and bring about pregnancy disorders. Growing evidence indicates that OS plays a major role in the pathophysiology of complications such as early pregnancy loss, placental insufficiency, preeclampsia, fetal growth restriction, and neonatal complications. Whether parturition induces oxidative stress is in dispute. In this review, we elaborate the influence of mode of delivery (vaginal delivery or cesarean delivery) on oxidative stress of neonates.MethodsA review of old and recent literature was done. The studies were divided according to the impact of mode of delivery on oxidative stress in the newborn.ResultsThere is a divergence in the oxidative stress production according to the mode of delivery.ConclusionsIn view of neonatal oxidative stress measures, no major difference was found between uncomplicated vaginal delivery and elective cesarean section.

The redox chemistry of copper tetraphenylporphyrin revisited

Mixing Cu(II)Cl2 with free base tetraphenylporphyrin ((H2(TPP)) in dry deaerated 1,2-dichloroethane surprisingly yields a mixture of Cu(II)(TPP) and Cu(III)(TPP). The later is long-lived in the absence of water and slowly decomposes within days to yield Cu(II)(TPP). Furthermore, in the presence of air, a slightly different CuIII porphyrin species forms, presumably, Cu(III)(TPP)•+, in which the Q-band is subject to a 10 nm red shift. The new Cu(III)(TPP) and Cu(III)(TPP)•+ differ in terms of absorption, fluorescence, electron paramagnetic resonance (EPR), and X-ray photoemission spectroscopy (XPS) when compared to the well-characterized Cu(II)(TPP), Cu(II)(TPP)•+, and Cu(II)(TPP)2+ species.

Antioxidants and Polyphenols: Concentrations and Relation to Male Infertility and Treatment Success

Oxidative stress is induced by reactive oxygen substances (ROS) that are known to affect male fertility. The aims of this study were to prospectively investigate and characterize total antioxidant and specifically polyphenols concentrations and their relations to sperm quality and fertility treatment success. During their infertility treatment, sixty-seven males were prospectively recruited to this study. After separation of the sperm from the semen sample, the semen fluid samples antioxidants and polyphenols concentrations were determined. Antioxidant concentration was significantly associated with sperm concentration and total motile count. Antioxidants concentration in the group of male with sperm concentration ≥ 15 × 106 was significantly higher than in the group of male with antioxidants concentration < 15 × 106 (830.3 ± 350 μM and 268.3 ± 220 μM, resp., p < 0.001). Polyphenols concentration did not differ between the groups of sperm concentration above and below 15 × 106 (178.7 ± 121 μM and 161.7 ± 61 μM, resp., p-NS). No difference was found between fertilization rates and antioxidants or polyphenols concentrations. This is the first study that reports on polyphenols concentration within semen fluid. More studies are needed in order to investigate polyphenols role in male fertility.