DNA double strand breaks but not interstrand crosslinks prevent progress through meiosis in fully grown mouse oocytes

There is some interest in how mammalian oocytes respond to different types of DNA damage because of the increasing expectation of fertility preservation in women undergoing chemotherapy. Double strand breaks (DSBs) induced by ionizing radiation and agents such as neocarzinostatin (NCS), and interstrand crosslinks (ICLs) induced by alkylating agents such as mitomycin C (MMC), are toxic DNA lesions that need to be repaired for cell survival. Here we examined the effects of NCS and MMC treatment on oocytes collected from antral follicles in mice, because potentially such oocytes are readily collected from ovaries and do not need to be in vitro grown to achieve meiotic competency. We found that oocytes were sensitive to NCS, such that this ionizing radiation mimetic blocked meiosis I and caused fragmented DNA. In contrast, MMC had no impact on the completion of either meiosis I or II, even at extremely high doses. However, oocytes treated with MMC did show ?-H2AX foci and following their in vitro maturation and parthenogenetic activation the development of the subsequent embryos was severely compromised. Addition of MMC to 1-cell embryos caused a similarly poor level of development, demonstrating oocytes have eventual sensitivity to this ICL-inducing agent but this does not occur during their meiotic division. In oocytes, the association of Fanconi Anemia protein, FANCD2, with sites of ICL lesions was not apparent until entry into the embryonic cell cycle. In conclusion, meiotic maturation of oocytes is sensitive to DSBs but not ICLs. The ability of oocytes to tolerate severe ICL damage and yet complete meiosis, means that this type of DNA lesion goes unrepaired in oocytes but impacts on subsequent embryo quality

We've Got A Cure For You! Disease Awareness Campaigns

Over the last twenty years, the use of disease awareness campaigns has become predominant in our everyday lives. What started out as a technique to market lifestyle drugs for cosmetics and sexual enhancements in the 1980s and 1990s, has now increased in usage to include many other areas of medicine. Its not uncommon to see drug advertisements in consumer magazines and on television for everything from psychotropic drugs, to drugs that are intended to improve the quality of everyday life for more average Americans. Indeed, its hard to find a popular press magazine that doesnt have at least one such advertisement, while most magazine issues have many such advertisements

Development and Competition of Corn Gromwell and Musk Thistle in Winter Wheat

Agronom

Disturbances of visual motion perception in bipolar disorder

OBJECTIVES: While cognitive deficits have been well documented in patients with bipolar disorder, visual perception has been less well characterized. Such deficits appear in schizophrenia, which shares genetic risk factors with bipolar disorder, and may contribute to disturbances in visual cognition and learning. METHODS: The present study investigated visual perception in bipolar disorder using psychophysical tests of contrast sensitivity, dot motion discrimination, and form discrimination. The relationship of these measures to mood state, medication status, and cognitive function was investigated. Sixty-one patients with type I bipolar disorder and 67 comparison subjects were tested. RESULTS: Results indicated a deficit in dot motion trajectory discrimination in both euthymic and ill individuals with bipolar disorder, as well as a global deficit in moving grating contrast sensitivity. Ill individuals with bipolar disorder were impaired in psychomotor processing, but this finding was not related to visual processing performance. CONCLUSIONS: These findings could be due to disturbances in specific visual pathways involved in the processing of motion properties, or to a more general deficit which impairs processing of temporally modulated stimuli

Guidance on Standardizing GPU Test Approaches

A standardized test method has been created to characterize and stress graphics processing units (GPU) during radiation effects testing

Rifts in Spreading Wax Layers

We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critical spreading rate a "spiky" rift with fracture zones almost parallel to the spreading direction developed. At yet higher spreading rates a second transition from the spiky rift to a zig-zag pattern occurred. In this regime the rift can be characterized by a single angle which was found to be dependent on the spreading rate. We show that the oblique spreading angles agree with a simple geometrical model. The coarsening of the zig-zag pattern over time and the three-dimensional structure of the solidified crust are also discussed.Comment: 4 pages, Postscript fil

2-{(E)-[1-(2-Hydroxy­ethyl)-3,3-dimethyl-3H-indol-1-ium-2-yl]vin­yl}-6-hydroxy­meth­yl-4-nitro­phenolate dihydrate

The title merocyanine-type mol­ecule, C21H22N2O5·2H2O, crystallizes in a zwitterionic form and has an E configuration at the styryl C=C bond. The styryl part of the mol­ecule and the indolium ring are slightly twisted and form a dihedral angle of 13.4 (1)°. The 1.274 (3) Å C—O bond length in the phenolate fragment is the longest among similar mol­ecules. Hydrogen bonds between solvent water mol­ecules, two hydroxyl groups and the phenolate O atom dictate the packing arrangement of mol­ecules in the crystal and join the mol­ecules into a two-dimensional polymeric network which propagates parallel to (001). Four water mol­ecules and four hydr­oxy groups form a centrosymmetric homodromic cyclic motif of O—H⋯O hydrogen bonds. Another cyclic centrosymmetric motif is generated by four water mol­ecules and two phenolate O atoms

Compendium of Current Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

Sensitivity of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage is studied. Devices tested include optoelectronics, digital, analog, linear bipolar devices, and hybrid devices

Formal Synthesis of (+)-Sorangicin A

The formal synthesis of (+)-sorangicin A was completed by two independent routes. Both approaches feature a cross metathesis reaction to form the C29-C30 bond to arrive at the bicyclic ether/tetrahydropyran fragment. Formation of the C15-C16 olefin to unite the dihydropyran fragment with the rest of the molecule was achieved by either a cross metathesis reaction or a Julia-Kocienski olefination