Low Frequency of Genetic Factors Gm(s) and Di(a) in Finland

1969 ◽  
Vol 19 (2) ◽  
pp. 180-184 ◽  
Author(s):  
Anja Tiilikainen ◽  
E. Ruoslahti ◽  
M. Seppälä ◽  
L. Mårtensson ◽  
Erna Van Loghem
Keyword(s):  
Genetic Factors ◽  
Low Frequency

-308 G > A of TNF-α gene promoter decreases the risk of multiple sclerosis: a meta-analysis

2010 ◽  
Vol 17 (6) ◽  
pp. 658-665 ◽  
Author(s):  
Yan Yang ◽  
Rulin Sun ◽  
Heng Yang ◽  
Fang Zheng ◽  
Feili Gong
Keyword(s):  
Multiple Sclerosis ◽  
Genetic Factors ◽  
Association Studies ◽  
Meta Analysis ◽  
Low Frequency ◽  
Gene Promoter ◽  
Tnf Α ◽  
Control Association ◽  
Necrosis Factor ◽  
Reduced Risk

Background: Environmental and genetic factors are thought to be involved in the pathogenesis of multiple sclerosis (MS). Polymorphisms of tumor necrosis factor (TNF)-α −308 were implicated in MS risk in several case–control association studies. However, the studies have shown inconsistent results. Objectives: To address the association of G/A polymorphisms of TNF-α −308 with MS risk by meta-analysis. Methods: Thirteen studies were included. Pooled odds ratios (ORs) together with 95% confidence intervals (CIs) were calculated. Results: A total of 1870 cases and 2769 controls were included in the meta-analysis. The pooled result indicated that −308 A allele is significantly associated with reduced risk of MS compared with −308 G allele (A vs. G, p = 0.022). The same pattern of the result was also obtained in the contrasts of AA + GA vs. GG ( p = 0.008) and GA vs. GG ( p = 0.007). For AA vs. GG or AA vs. GA + GG, no significant association was detected most likely caused by very low frequency or non-availability of homozygote genotype AA for all of the studies. Conclusions: TNF-α −308 A allele is associated with reduced risk of MS.

Factor XIII Val34Leu variant and the risk of myocardial infarction

2007 ◽  
Vol 97 (04) ◽  
pp. 635-641 ◽  
Author(s):  
Mona Shafey ◽  
Josdalyne Anderson ◽  
Dimitri Scarvelis ◽  
Steven Doucette ◽  
France Gagnon ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Protective Effect ◽  
Factor Xiii ◽  
Genetic Factors ◽  
Reference Group ◽  
Data Extraction ◽  
Meta Analysis ◽  
Low Frequency ◽  
Protective Effects ◽  
Case Control Studies

SummaryGenetic factors are thought to contribute to the pathogenesis of acute myocardial infarction (AMI).A common variant of factor XIII (FXIII), FXIII Val34Leu, may be protective against developing an AMI, but various studies show conflicting results. We performed a meta-analysis to determine whether the FXIII Val34Leu variant is associated with a decreased risk of AMI. One hundred ninety-five articles were reviewed and 12 case-control studies were selected. We included studies involving patients with objectively diagnosed AMIs (WHO criteria), provided that FXIII Val34Leu genotyping data were available. Inclusion decisions, quality assessment, and data extraction were conducted by two reviewers. Hypothesizing that the Leu allele was protective, we performed three analyses with the Val/Val genotype as the reference group. Pooled odds ratios (OR) and their 95% confidence intervals (95% CI) were determined. Prior to pooling, heterogeneity testing was performed using the I 2 statistic. These studies included a total of 8,743 patients, of which 3,663 were AMI patients and 5,080 were healthy controls. Using the random effects methods, protective effects were seen with the Leu/Val genotype alone (OR 0.79, 95% CI 0.68–0.93) and with Leu/Val and Leu/Leu genotypes combined (OR 0.79, 95% CI 0.66–0.93).There was also a protective effect with the Leu/Leu genotype alone, (not statistically significant: OR 0.83, 95% CI 0.61–1.12), likely due to the low frequency of this genotype. These results suggest that there is an association between the factor XIII Leu allele and a modest protective effect against AMI and may provide useful information in profiling susceptibility to myocardial infarction.

Chromosome pairing affinities between Old and New World species of Bromus section Pnigma

1984 ◽  
Vol 62 (3) ◽  
pp. 581-585 ◽  
Author(s):  
K. C. Armstrong
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
New World ◽  
Genetic Factors ◽  
Low Frequency ◽  
World Species ◽  
The North ◽  
Evolutionary Pathways ◽  
Bromus Benekenii ◽  
Eurasian Species

A low frequency of allosyndetic chromosome pairing occurred in interspecific hybrids between species having large chromosomes (Bromus benekenii (Lange) Trimen, 2n = 4x = 28; B. ramosus Huds., 2n = 4x = 28; B. pacificus Shear, 2n = 4x = 28) and species having small chromosomes (B. erectus Huds., 2n = 4x = 28; B. inermis Leyss, 2n = 4x = 28; B. pumpellianus Scribn., 2n = 4x = 28; B. riparius Rehm, 2n = 10x = 70; and B. variegatus, 2n = 2x = 14). These results are consistent with the suggestion that the large (predominantly Eurasion) and small (predominantly American) chromosome species of section Pnigma have followed different evolutionary pathways. Chromosome pairing in interspecific hybrids revealed low affinities between the chromosomes of the Eurasian species B. ramosus and the North American species B. pacificus. Thus there was no evidence that B. ramosus contained a form of the L genome found in American species. However genetic factors suppressing homoeologous pairing could be present in the allotetraploid parents.

scholarly journals Molecular genetic aspects of complicated myopia pathogenesis

2018 ◽  
Vol 11 (3) ◽  
pp. 48-56
Author(s):  
Alexey N. Kulikov ◽  
Sergey V. Churashov ◽  
Vladimir A. Reytuzov
Keyword(s):  
Refractive Error ◽  
Genetic Factors ◽  
Molecular Genetic ◽  
Low Frequency ◽  
Optical Power ◽  
Refractive Errors ◽  
Progressive Myopia ◽  
Remodeling Of Extracellular Matrix ◽  
The Impact ◽  
Modest Effect

Complicated myopia (CM) is not only a refractive error but a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and the axial length that causes the image to be focused off the retina. Genetic factors in progressive myopia play a key role in determining the impact of ecologic factors on refraction development. The majority of genetic variants underlying CM are characterized by modest effect and/or low frequency, which makes them difficult to identify using classic genetic approaches. The genes identified to date account for less than 10% of all myopia cases, suggesting the existence of a large number of yet unidentified low-frequency and/or small-effect variants, which underlie the majority of myopia cases. Genome analysis revealed dozens of loci associated with non-syndromic myopia, and showed that refractive errors are associated with mutations in genes that are involved in the growth and development of the eye by regulating ion transport, neurotransmission, remodeling of extracellular matrix of the retina and other ocular structures. Genetic study of refractive error provides a unique opportunity to detect key molecules that may play important roles in the development of refractive error. Identifying the molecular basis of refractive error helps to understand mechanisms, and subsequently to design rational therapeutic intervention for this condition.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

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