Search Results - (Author, Cooperation:M. N. Lee)

2014-05-03

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adaptive Immunity/genetics ; Alleles ; Alzheimer Disease/ethnology/genetics ; Autoimmune Diseases/ethnology/*genetics ; Autoimmunity/*genetics ; CD4-Positive T-Lymphocytes/*immunology ; Ethnic Groups/genetics ; Genetic Predisposition to Disease/ethnology/*genetics ; Genome-Wide Association Study ; Humans ; Immunity, Innate/genetics ; Monocytes/*immunology ; Multiple Sclerosis/ethnology/genetics ; Neurodegenerative Diseases/ethnology/*genetics ; Parkinson Disease/ethnology/genetics ; Polymorphism, Single Nucleotide ; Quantitative Trait Loci ; Rheumatic Fever/ethnology/genetics ; Transcriptome

2014-03-08

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adult ; Autoimmune Diseases/genetics ; Communicable Diseases/genetics ; Dendritic Cells/drug effects/*immunology ; Escherichia coli ; Female ; *Gene-Environment Interaction ; Genetic Loci ; Genome-Wide Association Study ; HEK293 Cells ; Host-Pathogen Interactions/*genetics ; Humans ; Influenza A virus ; Interferon Regulatory Factor-7/*genetics ; Interferon-beta/pharmacology ; Lipopolysaccharides/immunology ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Quantitative Trait Loci ; STAT Transcription Factors/*genetics ; Transcriptome ; Young Adult

0148-7280

spindles ; oocytes ; embryos ; microtubules ; cryopreservation ; electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Preovulatory mouse oocytes and 2-cell embryos were frozen with dimethyl sulfoxide and propanediol by an ultrarapid method. The survival of frozen oocytes was low (33-34%) compared to that of 2-cell embryos (78-79%) with either cryoprotectant. Development to blastocysts after postthaw culture was about 7-15% for oocytes and 79-80% for the embryos.Ultrarapid freezing preserves cell structure quite well as revealed by electron microscopy, but meiotic oocytes and late 2-cell embryos undergoing mitosis showed evidence of spindle disorganization involving loss or clumping of microtubules resulting in some scattering of chromosomes. Embryos developed from frozen eggs showed clear evidence of micronuclear formation and incomplete incorporation of chromosomal material into main nuclei. These experiments confirm our observations on freezing of human oocytes and show that spindle microtubules are sensitive to freeze-thawing and that cryopreservation could cause chromosomal aberrations during early development. A cautious approach to the introduction of oocyte freezing in human in vitro fertilization (IVF) programs is advocated.

20 Ill.

Electronic Resource

0148-7280

cryopreservation ; IVF ; in vitro fertilization ; embryo-freezing ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Previous studies by a French group (Fertil Steril 44:645-651, 1985) have shown that two-to eight-cell human embryos can survive slow freeze-thawing with propanediol in a biological freezer. These embryos were assessed for morphological appearance by phase-contrast microscopy. We assessed the structure of 25 frozen-thawed one- to 12-cell embryos, obtained from our in vitro fertilization (IVF) and GIFT programmes, by phase-contrast and electron microscopy, using the same method of cryopreservation. One-fourth of the embryos examined had all cells intact, and more than one-half the embryos had over 50% of their cells well preserved. Some of these embryos had unequal blastomeres and cytoplasmic fragments. Ultrastructural assessment revealed good preservation of fine structure in the intact blastomeres of all embryos and maintenance of cell-to-cell contacts. Most cytoplasmic organelles, cell membranes, and nuclei were well preserved compared to nonfrozen controls. The cells that were cryoinjured showed varying degrees of disorganization of the cell membrane, cytosol, and cellular membranes, including swelling and disruption of the nuclear envelope. Disruption of the zona was somewhat rare. Small cytoplasmic fragments were less prone to cryoinjury than blastomeres. The use of propanediol for embryo cryopreservation seems to be feasible; frozen embryos with more than 50% cells intact have produced 10 pregnancies after embryo transfer (Fertil Steril 46:268-272, 1986). Replacement of 17 frozen embryos in seven patients has resulted in a twin pregnancy in Singapore. However, the effects of freezing on the mitotic spindles of embryonic cells need to be investigated further.

9 Ill.

Electronic Resource

0377-0486

Chemistry ; Analytical Chemistry and Spectroscopy

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Physics

Room-temperature and low-temperature (10 K) Raman spectra of a single crystal NaH2PO4 were obtained for various polarizations. The polarization characteristics of the Raman spectra remained unchanged throughout the whole temperature range studied. This confirms that there is no phase transition in this crystal at least down to 10 K. High-frequency H modes showed the well known ABC-type three-band structure and correlated with O—H…O bond length.

6 Ill.

Electronic Resource