27 research outputs found

    Aqueous leaf extract of Moringa oleifera reduced intracellular ROS production, DNA fragmentation and acrosome reaction in Human spermatozoa in vitro

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    The effects of aqueous leaf extract of Moringa oleifera (MO) on human sperm functions and integrity was studied in vitro. Semen was obtained by masturbation after 3–5 days' abstinence from 34 healthy donors in Western Cape, South Africa. Liquefied semen was washed in human tubular fluid supplemented with 1% bovine serum albumin (HTF-BSA;1:5) with 10 min centrifugation at 300 g. Sperm suspensions were subsequently incubated with MO extract (0.625, 6.25, 62.5 and 625 µg/ml) for 1 hr, where HTF-BSA served as control. Sperm motility, vitality, DNA fragmentation, reactive oxygen species production, mitochondrial membrane potential, capacitation and acrosome reaction were assessed. Sperm motility, vitality, mitochondrial membrane potential and capacitation remained unchanged (p >.05). A dose-dependent decrease in sperm reactive oxygen species production (p <.0001), DNA fragmentation (p <.0001) and acrosome reaction (p <.001) was observed. An increase in the percentage of non-capacitated sperm (p <.01) was noted at 625 µg/ml

    The Impact of Storage Time and Seasonal Harvesting on Levels of Sutherlandins and Sutherlandiosides in Lessertia frutescens

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    In South Africa, an estimate of 70% of the population frequently uses traditional medicine for their health care needs. The use of Lessertia frutescens (Figure 1,2) by various cultural groups dates back to the earlier civilizations and continues to be used today to treat a multitude of ailments. Even in Western countries, L frutescens is used by many people for its anti-proliferative or anti-inflammatory activities. In establishing quality, safety and efficacy of traditional medicine, one would need to ensure that the crude material is of optimal quality

    One sixth of Amazonian tree diversity is dependent on river floodplains

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    Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.Naturali

    Author Correction: One sixth of Amazonian tree diversity is dependent on river floodplains

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    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    A novel approach for the selection of human sperm using annexin V-binding and flow cytometry

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    Objective: To develop a method whereby sperm with phosphatidylserine externalization can be separated from those without this feature. Because annexin V binds phosphatidylserine, this study is using this feature to select functional spermatozoa. In addition, the relationship between annexin V binding in human spermatozoa and normal sperm morphology according to strict criteria was to be assessed. Design: Prospective study. Setting: Department of Obstetrics and Gynaecology of Stellenbosch University at Tygerberg Academic Hospital, Tygerberg, South Africa. Patient(s): Semen from 14 healthy sperm donors. Exclusion criterion was the presence of less than 20 × 106/mL total motile spermatozoa in the original sample. Main Outcome Measure(s): Annexin V-negative sperm, annexin V-positive sperm, normal sperm morphology. Intervention(s): An aliquot of a semen sample after double density gradient centrifugation was incubated with annexin V fluorescein isothiocyanate conjugate (FITC). Cell fluorescence signals were determined using a FACScalibur flow cytometer equipped with a FACSSort fluidic sorting module. The sorting procedure delivered two sperm subpopulations: annexin V-negative and annexin V-positive. Morphology slides were made and the sperm morphology was assessed according to strict criteria. Result(s): There was a significant enrichment of annexin V-negative sperm as well as morphologically normal sperm in the annexin V-negative subgroup after separation with flow cytometry. The percentage of morphologically normal sperm increased from 8.3% in the control to 11.9% in the annexin V-negative fraction, whereas the percentage of annexin V-positive sperm decreased to 5.7%. Conclusion(s): The annexin V-negative sperm subpopulation had morphologically superior quality sperm compared to annexin V-positive sperm. It is important to select morphologically normal sperm during intracytoplasmic sperm injection (ICSI) as it may contribute to increased implantation and pregnancy rates (PR). © 2009 American Society for Reproductive Medicine.Articl

    Comparison between swim-up and glass wool column filtration of human semen in a gamete intrafallopian transfer program

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    This study compared swim-up and glass wool filtration in both pregnancy outcome and fertilization of excess oocytcs in patients undergoing gamete intrafallopian transfer. Gamete intrafallopian transfer patients were retrospectively included in the study group (n = 52). The criteria for inclusion were as follows: Semen had to have been prepared by means of glass wool filtration and at least 2 metaphase II oocytes had to have been transferred. Each patient from this group was then carefully matched with another patient according to specific criteria (number of metaphase II oocytes aspirated and transferred, normal sperm morphology, wife's age, the absence of anti-sperm antibodies, semen preparation by means of the swim-up procedure). Fourteen patients were matched with themselves (groups A1 and A2) and 38 patients were matched with another patient (groups B and C). The results indicate that there was no significant difference in the fertilization and pregnancy probabilities of sperm prepared by means of glass wool filtration or swim-up procedure. The comparative pregnancy rates for the groups were A1 (7.1%) versus A2 (7.1%) and B (28.9%) versus C (31.6%). Factors other than fertilization and pregnancy potential may have a greater influence on choosing the optimum sperm preparation procedure.Articl
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