The sensitivity of the DNA damage checkpoint prevents oocyte maturation in endometriosis

Mouse oocytes respond to DNA damage by arresting in meiosis I through activity of the Spindle Assembly Checkpoint (SAC) and DNA Damage Response (DDR) pathways. It is currently not known if DNA damage is the primary trigger for arrest, or if the pathway is sensitive to levels of DNA damage experienced physiologically. Here, using follicular fluid from patients with the disease endometriosis, which affects 10% of women and is associated with reduced fertility, we find raised levels of Reactive Oxygen Species (ROS), which generate DNA damage and turn on the DDR-SAC pathway. Only follicular fluid from patients with endometriosis, and not controls, produced ROS and damaged DNA in the oocyte. This activated ATM kinase, leading to SAC mediated metaphase I arrest. Completion of meiosis I could be restored by ROS scavengers, showing this is the primary trigger for arrest and offering a novel clinical therapeutic treatment. This study establishes a clinical relevance to the DDR induced SAC in oocytes. It helps explain how oocytes respond to a highly prevalent human disease and the reduced fertility associated with endometriosis

Compatibility of the Omnican (R) Pen Needles with Insulin Pens, Humapen (R) and Novopen (R)

This study was carried out to assess accuracy of Omnican (R) insulin pen needles (29G and 30G) by measuring the weight of insulin delivered in each of 10 depressions of the plunger comparing these using other pen-injectors (Humapen (R) and Novopen (R) for each gauge. We found that the needle-to-needle variation was not statistically significant when the needles were used to dispense insulin using either of the insulin pens (Humapen (R) and Novopen (R). HumaPen (R) insulin pen was found to deliver the insulin closer to set target volume using either gauge (29G and 30G) of the Omnican (R) needles in some of the insulin ranges used in this study

Factors associated with physical inactivity among school-going adolescents: data from the Malaysian School-Based Nutrition Survey 2012

The importance of physical activity to health is well recognized. Good health habits should begin from a young age. This article aims to explore physical activity among Malaysian school adolescents and factors associated with it. Data from the Malaysian School-Based Nutrition Survey (MSNS), comprising a nationally representative sample of school-going children aged 10 to 17 years, were used. The overall prevalence of physically inactive adolescents was 57.3%. Age in years (adjusted odds ratio = 1.2; 95% confidence interval = 1.16-1.23), gender - females (adjusted odds ratio = 2.9; 95% confidence interval = 2.66-3.10), afternoon school session, breakfast consumption (no breakfast and irregular breakfast), body mass index status (obese and underweight), and body weight perception (underweight perceivers) were significant factors associated with physical inactivity among Malaysian adolescents. Thus, there is evidence that programs to promote physical activity in this group should consider the combination of the aforementioned factors at the household, school, and community levels

Induced endometrial trauma (endometrial scratch) in the mid-luteal menstrual cycle phase preceding first cycle IVF/ICSI versus usual IVF/ICSI therapy: study protocol for a randomised controlled trial

Endometrial trauma commonly known as endometrial scratch (ES) has been shown to improve pregnancy rates in women with a history of repeated implantation failure undergoing in vitro fertilisation (IVF), with or without intracytoplasmic sperm injection (ICSI). However, the procedure has not yet been fully explored in women having IVF/ICSI for the first time. This study aims to examine the effect of performing an ES in the mid-luteal phase prior to a first-time IVF/ICSI cycle on the chances of achieving a clinical pregnancy and live birth. If ES can influence this success rate, there would be a significant cost saving to the National Health Service through decreasing the number of IVF/ICSI cycles necessary to achieve a pregnancy, increase the practice of single embryo transfer and consequently have a large impact on risks and costs associated with multiple pregnancies. This 30-month, UK, multicentre, parallel group, randomised controlled trial includes a 9-month internal pilot and health economic analysis recruiting 1044 women from 16 fertility units. It will follow up participants to identify if IVF/ICSI has been successful and live birth has occurred up to 6 weeks post partum. Primary analysis will be on an intention-to-treat basis. A substudy of endometrial samples obtained during the ES will assess the role of immune factors in embryo implantation. Main trial recruitment commenced on January 2017 and is ongoing.Participants randomised to the intervention group will receive the ES procedure in the mid-luteal phase of the preceding cycle prior to first-time IVF/ICSI treatment versus usual IVF/ICSI treatment in the control group, with 1:1 randomisation. The primary outcome is live birth rate after completed 24 weeks gestation. South Central-Berkshire Research Ethics Committee approved the protocol. Findings will be submitted to peer-reviewed journals and abstracts to relevant national and international conferences. ISRCTN23800982; Pre-results

Quantification of intracellular payload release from polymersome nanoparticles

Polymersome nanoparticles (PMs) are attractive candidates for spatio-temporal controlled delivery of therapeutic agents. Although many studies have addressed cellular uptake of solid nanoparticles, there is very little data available on intracellular release of molecules encapsulated in membranous carriers, such as polymersomes. Here, we addressed this by developing a quantitative assay based on the hydrophilic dye, fluorescein. Fluorescein was encapsulated stably in PMs of mean diameter 85 nm, with minimal leakage after sustained dialysis. No fluorescence was detectable from fluorescein PMs, indicating quenching. Following incubation of L929 cells with fluorescein PMs, there was a gradual increase in intracellular fluorescence, indicating PM disruption and cytosolic release of fluorescein. By combining absorbance measurements with flow cytometry, we quantified the real-time intracellular release of a fluorescein at a single-cell resolution. We found that 173 ± 38 polymersomes released their payload per cell, with significant heterogeneity in uptake, despite controlled synchronisation of cell cycle. This novel method for quantification of the release of compounds from nanoparticles provides fundamental information on cellular uptake of nanoparticle-encapsulated compounds. It also illustrates the stochastic nature of population distribution in homogeneous cell populations, a factor that must be taken into account in clinical use of this technology.</p

Spin correlations in the algebraic spin liquid - implications for high Tc superconductors

We propose that underdoped high $T_c$ superconductors are described by an algebraic spin liquid (ASL) at high energies, which undergoes a spin-charge recombination transition at low energies. The spin correlation in the ASL is calculated via its effective theory - a system of massless Dirac fermions coupled to a U(1) gauge field. We find that without fine tuning any parameters the gauge interaction strongly enhances the staggered spin correlation even in the presence of a large single particle pseudo-gap. This allows us to show that the ASL plus spin-charge recombination picture can explain many highly unusual properties of underdoped high $T_c$ superconductors.Comment: 22 pages, 18 figures, submitted to PR

Regulation of lipid signaling at the Golgi by the lipid phosphatases hSAC1 and OCRL1

Phosphoinositides are key lipid signaling molecules present in membranes of all eukaryotes. Different species of phosphoinositides serve as membrane signposts at distinct cellular compartments. This assymetric distribution of phosphoinositides is achieved by the presence of an elaborate set of lipid kinases and phosphatases operating at specific organelle membranes. The lipid phosphatase SAC1 is found in both endoplasmic reticulum (ER) and Golgi. Similar to yeast Sac1p, human SAC1 (hSAC1) is the major phosphatidylinositol-4-phosphatase (PI(4)P-phosphatase). Distinct localization of hSAC1 in both ER and Golgi membranes suggests that this PI(4)P-phosphatase has compartment specific roles in regulating steady state distribution of PI(4)P in these organelles. OCRL1 is a Golgi and endosomal localized PI(4,5)P2 5-phosphatase that is implicated in a severe X-linked disease, Lowe syndrome, which is characterized by congenital cataracts, Fanconi syndrome and mental retardation. How mutations in OCRL1 cause Lowe syndrome is unknown. The functional analysis of hSAC1 and OCRL1 in regulating Golgi PI(4)P and PI(4,5)P2 is the main focus of this work. Confocal immunofluorescence and immuno-electron microscopy (immuno-EM) show that PI(4)P and hSAC1 form an opposing gradient in the Golgi. hSAC1 is highly enriched at Golgi cisternal membranes while PI(4)P is concentrated at the trans-Golgi network (TGN) where cargo proteins are packaged and exported. Golgi enzymes such as N-acetylglucosaminyltransferase I (NacT1) and mannosidase II (ManII) are preferentially found in these PI(4)P-depleted areas. siRNA-mediated knock-down of hSAC1 leads to accumulation of PI(4)P at Golgi, plasma membrane and endosomal like structures and causes mislocalization of ManII and NacT1. This data suggests that SAC1 establishes PI(4)P-depleted Golgi regions that are important for proper localization and recycling of Golgi resident enzymes. Conversely, depletion of OCRL1 does not disturb Golgi morphology or induce mislocalization of Golgi resident enzymes. However, bulk secretion is inhibited in OCRL1 depleted cells. The OCRL1-b splice variant populates TGN and early endosomal compartment whereas the OCRL1-a splice variant containing an extra 8 amino acid acidic cluster is found only in a subset of late endosomal/ lysosomal membranes. This distinct localization of OCRL1 splice variants indicates that each isoform might regulate different trafficking routes by regulating PI(4,5)P2 levels at these compartments. Together, the results show that hSAC1 and OCRL1 establish distinct phosphoinositide-specific domains within the Golgi that are instrumental for segregation of anterograde trafficking from the recycling of resident Golgi enzymes

Synthesis, Formation And Characterization Of Nanoscale Zeolite Type W Base Catalyst

Zeolite W (MER topology) is a very important zeolite in catalysis and separation industries but its synthesis requires the use of organic structure-directing agents (OSDAs) and long crystallization time. This project aims to synthesize and study the formation of nanosized zeolite W without organic structure-directing agent with shortened synthesis time while using it as heterogeneous catalyst for various base-catalyzed organic reactions. The first part focuses on studying the effect of the synthesis parameters such as heating temperature, reaction time and hydrogel chemical compositions on the crystallization behaviour of zeolite W. It is found that the synthesis parameters have significant impact on the crystallization rate, purity of the zeolite phase, particle size and morphology of the zeolite product. By tuning the synthesis parameters, zeolite W with four distinct morphologies (nanorods, wheatsheaf-like, bullet-like and prismatic) can be obtained. Further investigation into the relationship between different morphologies and their surface basicity found that the surface basicity is linearly proportional to the surface area of the zeolites. Next, the time-dependent study on the nucleation and crystal growth process of nanosized zeolite W synthesized with reactive bamboo leaves ash (BLA) was reported. Various spectroscopic, microscopic and analytical techniques are used to follow the whole crystallization process. The zeolite undergoes amorphous phase reorganization twice before the occurrence of nucleation, crystallization and crystal growth. The zeolite W obtained exhibit nanorods morphology and tend to assemble in parallel forming bulkier bundle-like secondary particles. Lastly, the synthesis of nanocrystalline zeolite W with hierarchical mesoporosity under microwave heating condition was discussed