Abnormal Size (abnormal + size)

Distribution by Scientific Domains


Selected Abstracts


Abnormal giant cells in the cerebral lesions of tuberous sclerosis complex

CONGENITAL ANOMALIES, Issue 1 2007
Masashi Mizuguchi
ABSTRACT Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by mutations of either of the two tumor suppressor genes, TSC1 and TSC2, encoding hamartin and tuberin, respectively. TSC is pathologically characterized by the occurrence of multiple hamartias (focal dysplasias) and hamartomas (benign tumors) in the brain and many other organs. Cortical tubers are hamartias in the cerebral cortex responsible for many neuropsychiatric symptoms of TSC. Unlike TSC-associated hamartomas, cortical tubers do not result from second somatic mutations of the TSC gene, and the mechanism by which they occur remains obscure. Histologically, the most conspicuous feature of cortical tubers is the presence of abnormal giant cells, which show abnormal size and differentiation. Recent studies on human TSC and its animal models have elucidated the critical roles of hamartin and tuberin regulating the growth and differentiation of neural cells. [source]


High-Temperature Instability of Li- and Ta-Modified (K,Na)NbO3 Piezoceramics

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2008
Yongli Wang
This paper addresses the high-temperature instability of Li- and Ta-modified (K,Na)NbO3 piezoceramics. The grains with abnormal size evolve out of the fine matrix grains during high-temperature annealing. They are found to be precipitates with a tetragonal tungsten bronze structure, which result from the volatilization and segregation of the alkali metal elements. With the growth of the abnormal grains the composition of the perovskite matrix phase also changes remarkably, as has been suggested by EDX analysis (for Na) and electric measurements (for Li). These variations lead to a large increase in the tetragonal/orthorhombic phase transition temperature and appreciable variations in the dielectric, ferroelectric, and piezoelectric properties of the ceramic samples. Control of the volatilization of the alkali metal elements can efficiently depress the abnormal grain growth and the compositional segregation. [source]


Ultrasonically measured horizontal eye muscle thickness in thyroid associated orbitopathy: cross-sectional and longitudinal aspects in a Danish series

ACTA OPHTHALMOLOGICA, Issue 2 2003
Hans C. Fledelius
Abstract. Purpose:, To analyse horizontal extraocular muscle findings by ultrasound and exophthalmometry in a tertiary endocrinology centre series of patients with thyroid associated orbitopathy (TAO). Methods:, The 90 thyroid patients included underwent ultrasonic measurement of horizontal eye muscle thickness by a B-scan based technique carried out in addition to their general ophthalmic evaluation. As an indicator of mainly advanced TAO, longterm prednisone or cyclosporine A was given to many of the patients, and drug-resistant visual loss indicated decompression surgery in four of the 90 patients. Thirty-four patients underwent repeated muscle recordings over 15,49 months; this allowed for cross-sectional analysis and the outlining of longitudinal trends. Results and Conclusions:, (A) Although marginally overlapping, all four muscle groups were significantly thicker in the study group than in normal control subjects. The mean of the sum of all four muscles was 16.8 mm (range 13.6,21.7 mm) in the control group versus 22.6 mm (range 15.5,36.4 mm) in the thyroid group. (B) Using the clinical NOSPECS grading, more advanced eye involvement was found to generally result in a higher exophthalmometric measurement of protrusion and eye muscle thickness. However, slender rectus muscles and/or normal exophthalmometric values might occur even in advanced orbitopathy. (C) Over a period of 2,4 years, only a few of 34 patients with satisfactory serial ultrasonic measurements returned to their premorbid ophthalmic status. Typically, the extraocular muscles kept their abnormal size after having become clinically quiescent (fibrotic). (D) We found no safe indication regarding disease stage, active or late, from the ultrasonic appearance of the muscle tissue. (E) Discrepancies between various normative eye muscle studies are discussed with regard to computer tomography and magnetic resonance imaging. [source]


Inactivation of the UGPase1 gene causes genic male sterility and endosperm chalkiness in rice (Oryza sativa L.)

THE PLANT JOURNAL, Issue 2 2008
Mi-Ok Woo
Summary A rice genic male-sterility gene ms-h is recessive and has a pleiotropic effect on the chalky endosperm. After fine mapping, nucleotide sequencing analysis of the ms-h gene revealed a single nucleotide substitution at the 3,-splice junction of the 14th intron of the UDP-glucose pyrophosphorylase 1 (UGPase1; EC2.7.7.9) gene, which causes the expression of two mature transcripts with abnormal sizes caused by the aberrant splicing. An in vitro functional assay showed that both proteins encoded by the two abnormal transcripts have no UGPase activity. The suppression of UGPase by the introduction of a UGPase1-RNAi construct in wild-type plants nearly eliminated seed set because of the male defect, with developmental retardation similar to the ms-h mutant phenotype, whereas overexpression of UGPase1 in ms-h mutant plants restored male fertility and the transformants produced T1 seeds that segregated into normal and chalky endosperms. In addition, both phenotypes were co-segregated with the UGPase1 transgene in segregating T1 plants, which demonstrates that UGPase1 has functional roles in both male sterility and the development of a chalky endosperm. Our results suggest that UGPase1 plays a key role in pollen development as well as seed carbohydrate metabolism. [source]