Distribution and high frequency of novel alleles at NF1 polymorphic markers in the Italian population

1999 ◽  
Vol 13 (6) ◽  
pp. 415-420 ◽  
Author(s):  
F Natacci ◽  
P Colapietro ◽  
P Riva ◽  
L Corrado ◽  
LN Rossi ◽  
...  
Keyword(s):  
High Frequency ◽  
Italian Population ◽  
Polymorphic Markers ◽  
Novel Alleles

High frequency hearing loss in the elderly: effect of age and noise exposure in an Italian group

2011 ◽  
Vol 125 (8) ◽  
pp. 776-780 ◽  
Author(s):  
A Ciorba ◽  
A Benatti ◽  
C Bianchini ◽  
C Aimoni ◽  
S Volpato ◽  
...  
Keyword(s):  
High Frequency ◽  
Noise Exposure ◽  
The Elderly ◽  
Italian Population ◽  
High Frequency Hearing Loss ◽  
High Frequencies ◽  
Threshold Difference ◽  
Hearing Thresholds ◽  
And Gender ◽  
Effect Of Age

AbstractObjective:To describe the effect of age and noise on high frequency hearing thresholds in an Italian population aged 70 years and older, in order to investigate the interaction between presbycusis and noise exposure.Methods:We compared 460 subjects: 367 affected by presbycusis alone (204 women and 163 men) and 93 affected by presbycusis and noise exposure (eight women and 85 men). Pure tone average hearing thresholds, for each ear, were compared between groups, and between sexes and ages within groups.Results:A slight threshold difference was found between the two groups at 4 kHz. After adjusting for age and gender, this difference was found to be related only to differing patient age. Men's and women's thresholds differed significantly in both groups, especially at high frequencies, at which threshold deterioration was worse in men than women.Conclusion:The threshold differences between patients with presbycusis with and without noise exposure were limited. Larger studies are needed to assess the relative effects of ageing and noise exposure on hearing thresholds.

scholarly journals Founder effect for the highly prevalent R337H mutation of tumor suppressor p53 in Brazilian patients with adrenocortical tumors

2004 ◽  
Vol 48 (5) ◽  
pp. 647-650 ◽  
Author(s):  
Emilia M. Pinto ◽  
Ana Elisa C. Billerbeck ◽  
Maria Candida B.F. Villares ◽  
Sorahia Domenice ◽  
Berenice B. Mendonça ◽  
...  
Keyword(s):  
High Frequency ◽  
Great Majority ◽  
Polymorphic Markers ◽  
Tumor Suppressor P53 ◽  
Analysis Software ◽  
Chi Square ◽  
Fragment Analysis ◽  
Adrenocortical Tumors ◽  
Normal Individuals ◽  
Chi Square Test

The incidence of adrenocortical tumors in children from the Southern region of Brazil is higher than in other parts of the world. This fact has been related to the identification of an inherited missense mutation of the p53 (R337H) at high frequency (78-97%) in Brazilian children with adrenocortical tumors. Given the high frequency of this germline mutation in the Brazilian population, it is very likely that the R337H mutation has arisen from a common origin. In this study, we analyzed two highly polymorphic intragenic markers (VNTRp53 and p53CA) in 22 patients (16 children and 6 adults) with adrenocortical tumors carrying the germline R337H mutation and 60 normal individuals using GeneScan Fragment Analysis software. We found six and sixteen different alleles for the VNTRp53 and p53CA polymorphic markers, respectively. Two distinct alleles, both with 122 bp, were found in 56.8% (VNTRp53) and 54.5% (p53CA) of the 44 alleles from patients with adrenocortical tumors associated with the R337H mutation. Differently, these same VNTRp53 and p53CA alleles were found in 18.3% and 14.2% of 120 alleles from normal individuals, respectively (p<0.01, Chi-square test). An identical haplotype for p53 locus was also identified in 95% of the apparently unrelated Brazilian patients with adrenocortical tumors carrying the R337H mutation. In conclusion, we demonstrated a strong evidence of co-segregation between two intragenic polymorphic p53 markers and the germline R337H mutation, indicating that this mutation has originated from a single common ancestral in the great majority of the Brazilian patients with adrenocortical tumors.

scholarly journals High frequency of biotinidase deficiency in Italian population identified by newborn screening

2020 ◽  
Vol 25 ◽  
pp. 100689
Author(s):  
Silvia Funghini ◽  
Rodolfo Tonin ◽  
Sabrina Malvagia ◽  
Anna Caciotti ◽  
Maria Alice Donati ◽  
...  
Keyword(s):  
Newborn Screening ◽  
High Frequency ◽  
Biotinidase Deficiency ◽  
Italian Population

scholarly journals Two founder mutations in theSEC23Bgene account for the relatively high frequency of CDA II in the Italian population

2011 ◽  
Vol 86 (9) ◽  
pp. 727-732 ◽  
Author(s):  
Roberta Russo ◽  
Antonella Gambale ◽  
Maria Rosaria Esposito ◽  
Maria Luisa Serra ◽  
Annaelena Troiano ◽  
...  
Keyword(s):  
High Frequency ◽  
Italian Population ◽  
Founder Mutations ◽  
Cda Ii

scholarly journals Monocytes Heterozygous for the Asp299Gly and Thr399Ile Mutations in the Toll-like Receptor 4 Gene Show No Deficit in Lipopolysaccharide Signalling

2003 ◽  
Vol 197 (12) ◽  
pp. 1787-1791 ◽  
Author(s):  
Clett Erridge ◽  
John Stewart ◽  
Ian R. Poxton
Keyword(s):  
High Frequency ◽  
Bacterial Infections ◽  
Physiological Responses ◽  
Italian Population ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Gram Negative ◽  
Increased Risk ◽  
Tlr4 Gene ◽  
Efficient Recognition

Toll-like receptor 4 (TLR4)-mediated recognition of lipopolysaccharide (LPS) is required for efficient recognition of Gram-negative bacterial infections. Two commonly occurring mutations in the human TLR4 gene (Asp299Gly and Thr399Ile) have recently been shown to be associated with blunted physiological responses to inhaled LPS, and with increased risk of Gram-negative bacteraemia in sepsis patients and reduced risk of atherosclerosis in an Italian population. Here we show that monocytes from individuals heterozygous for both mutations in the TLR4 gene exhibit no deficit in recognition of LPS of Escherichia coli, Neisseria meningitidis, Bacteroides fragilis, Yersinia pestis, Chlamydia trachomatis, Porphyromonas gingivalis, or Pseudomonas aeruginosa. We propose that the relatively high frequency of these mutations in the Caucasian population may reflect modified responses of carriers to alternative TLR4 agonists.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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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