17 research outputs found
Controversy and consensus on the management of elevated sperm DNA fragmentation in male infertility: A global survey, current guidelines, and expert recommendations
Purpose
Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition.
Materials and Methods
An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method.
Results
A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4–6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated.
Conclusions
This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians
Carbohydrate
Carbohydrates are the most abound macromolecules on earth, and they serve different functions within the cell. The purpose of the book is to provide a glimpse into various aspects of carbohydrates by presenting the research of some of the scientists who are engaged in the development of new tools and ideas used to reveal carbohydrate metabolism in health and diseases and as material to mimic the carbohydrate surfaces that take part in molecular recognition, often from very different perspectives. This book covers broad topics in carbohydrate including quality carbohydrates on the prevention and therapy of noncommunicable diseases, lactate, and glycolysis, as biomass in biofuel production, targets for cancer treatment and as biomaterial
Plant Origins of Propolis from Hakkari, Turkey
In this study, palynological analysis of 64 propolis samples from Hakkari province in Eastern Anatolia Region of Turkey was carried out. By microscopic analysis method, pollen diagnosis was made in propolis samples, and plants which may be propolis sources, were estimated. As a result, 71 plant taxa belonging to 34 families were identified at different rates in propolis samples. The pollens of the plants belonging to the family Apiaceae (2.7%-35%), Asteraceae (3.4%-35.4%) and, Fabaceae (12%-66%) were considerably found in the propolis of the Hakkari province. This study is the first report introducing the plant profile of Hakkari propolis in detail
Comparison of the effects of different sa concentrations on senescence in excised rocket (Eruca sativa L.) cotyledons
Senescence, accepted as the last phase of growth in plants, is characterized by a series of degenerative events that decrease the metabolic activity and eventually cause the death of cells, tissues and organs. In the present studies the effect of salicylic acid, a phenolic substance that recently came to be defined as plant growth regulator, especially increasing immunity of plants against infections, regulating thermogenesis in Arum flowers, inhibiting ethylene biosynthesis and germination, reversing the effects of abscisic acid and blocking the wound-induced response on the senescence of excised cotyledons of cultivated Eruca sativa L., (Rocket) was examined. Cotyledons of ten-day-seedlings of E. sativa were cut apart from the petiole and.-used as experiment materials. The fresh weight of cut cotyledons were measured and they were then incubated in 3 ml of salicylic acid at 10(-3), 10(-1), 10(-7), 10(-9) M concentrations and in distilled water as control. After 4 hours of light exposure in climatie room (25 +/- 2 degrees C), total chlorophyll amount, total protein content, peroxidase activity and protein analysis with SDS-PAGE method were assayed spectrophotometrically with biochemical methods. Furthermore, the effect of salicylic acid on fresh weights of rocket cotyledons was studied
Chemical Characterization Of 64 Propolis Samples From Hakkari, Turkey
Propolis is a resinous substance produced by honey bees from various plants they visit. Sixty-four propolis samples were collected from different localities of four districts (Merkez, Yiiksekova, Semdinli, and Qukurca) in Hakkari territory. Ethanol extracts of the propolis samples were prepared, and their chemical contents were determined by gas chromatography-mass spectroscopy (GC-MS). Flavonoids were generally found in a high concentration in Semdinli samples of Turkey. Twenty-seven coumarins were identified in the 28 propolis samples among studied 64 ones. Except suberosin, the coumarins were never reported before in any propolis sample with Turkish origin. The propolis samples belonging to Yuksekova were found to be richer in coumarins than the others, and the most richest one among the Yfiksekova apiaries, was found to be Akocak sample (Y2) with 41.99% total yield, followed by Akcall sample (Y5) (30.86%). This is a first comprehensive and original report about the chemical profile of propolis samples from Hakkari. The propolis samples from Hakkari exhibited a chemical content rich in flavonoids including coumarins and furocoumarins.WoSScopu
Glu-370 in the large subunit influences the substrate binding, allosteric, and heat stability properties of potato ADP-glucose pyrophosphorylase
ADP-glucose pyrophosphorylase (AGPase) is a key allosteric enzyme in plant starch biosynthesis. Plant AGPase is a heterotetrameric enzyme that consists of large (LS) and small subunits (SS), which are encoded by two different genes. In this study, we showed that the conversion of Glu to Gly at position 370 in the LS of AGPase alters the heterotetrameric stability along with the binding properties of substrate and effectors of the enzyme. Kinetic analyses revealed that the affinity of the (LSSSWT)-S-E370G AGPase for glucose 1-phosphate is 3-fold less than for wild type (WT) AGPase. Additionally, the (LSSSWT)-S-E370G AGPase requires 3-fold more 3-phosphogyceric acid to be activated. Finally, the LS(E370G)SS(WT)AGPase is less heat stable compared with the WT AGPase. Computational analysis of the mutant Gly-370 in the 3D modeled LS AGPase showed that this residue changes charge distribution of the surface and thus affect stability of the LS AGPase and overall heat stability of the heterotetrameric AGPase. In summary, our results show that LSE370 intricately modulate the heat stability and enzymatic activity of potato the AGPase. (C) 2016 Elsevier Ireland Ltd. All rights reserved
Enhanced Heterotetrameric Assembly of Potato ADP-Glucose Pyrophosphorylase Using Reverse Genetics
ADP-glucose pyrophosphorylase (AGPase) is a key allosteric enzyme in plant starch biosynthesis. Plant AGPase is a heterotetrameric enzyme that consists of large (LS) and small subunits (SS), which are encoded by two different genes. Computational and experimental studies have revealed that the heterotetrameric assembly of AGPase is thermodynamically weak. Modeling studies followed by the mutagenesis of the LS of the potato AGPase identified a heterotetramer-deficient mutant, LSR88A. To enhance heterotetrameric assembly, LSR88A cDNA was subjected to error-prone PCR, and second-site revertants were identified according to their ability to restore glycogen accumulation, as assessed with iodine staining. Selected mutations were introduced into the wild-type (WT) LS and co-expressed with the WT SS in Escherichia coli glgC(-). The biochemical characterization of revertants revealed that (LSSSWT)-S-I90V, (LSSSWT)-S-Y378C and (LSSSWT)-S-D410G mutants displayed enhanced heterotetrameric assembly with the WT SS. Among these mutants, (LSSSWT)-S-Y378C AGPase displayed increased heat stability compared with the WT enzyme. Kinetic characterization of the mutants indicated that the (LSSSWT)-S-I90V and (LSSSWT)-S-Y378C AGPases have comparable allosteric and kinetic properties. However, the (LSSSWT)-S-D410G mutant exhibited altered allosteric properties of being less responsive and more sensitive to 3-phosphoglyceric acid activation and inorganic phosphate inhibition. This study not only enhances our understanding of the interaction between the SS and the LS of AGPase but also enables protein engineering to obtain enhanced assembled heat-stable variants of AGPase, which can be used for the improvement of plant yields
Enhancement of the lipid productivity and fatty acid methyl ester profile of Chlorella vulgaris by two rounds of mutagenesis
In this study, we applied a second round of random mutagenesis using ethyl methanesulfonate to further increase the lipid productivity of a Chlorella vulgaris mutant strain. We generated a mutant (UV715-EMS25) with a lipid content and biomass that were respectively 67% and 35% higher than those of the wild type (WT). The highest achieved lipid productivity in UV715-EMS25 was 91 mg L-1 day(-1). Gas chromatography-mass spectrophotometric analysis revealed that the fatty acid methyl ester content of the mutant was 3.9-fold higher compared with that of WT cells. Amounts of saturated and monounsaturated fatty acids were also higher in the mutant, while the total amounts of polyunsaturated fatty acids were lower. Finally, the mutant displayed superior lipid productivity compared with the WT during pilot-scale cultivation in a flat panel photobioreactor. All these results demonstrate that UV715-EMS25 is highly suitable for biodiesel production