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Specific Structural (specific + structural)
Selected AbstractsRational approaches to the neurobiologic study of youth at risk for bipolar disorder and suicideBIPOLAR DISORDERS, Issue 5p2 2006M Elizabeth Sublette Objectives:, The aims of this paper are to provide an overview of neuroimaging findings specific to bipolar disorder and suicide, and to consider rational approaches to the design of future in vivo studies in youth at risk. Methods:, Neuroimaging and related neurobiological literature pertaining to bipolar disorder and suicide in adult and pediatric samples was reviewed in a non-quantitative manner. Results:, Specific structural and functional brain findings in bipolar disorder are described, where possible in the context of relevant current neurobiological theories of etiology. Diagnostic and prognostic implications are discussed. Conclusions:, The simultaneous use of complementary neurobiological approaches may be a powerful way of identifying and validating factors reliably associated with bipolar disorder and suicide. A profile of neurobiological markers with which to screen for bipolar disorder and suicide risk may provide for earlier and more accurate diagnosis, perhaps even in the pre- or subsyndromal stages in high-risk youth. [source] The porcine trophoblastic interferon-,, secreted by a polarized epithelium, has specific structural and biochemical propertiesFEBS JOURNAL, Issue 11 2002Avrelija Cenci At the time of implantation in the maternal uterus, the trophectoderm of the pig blastocyst is the source of a massive secretion of interferon-gamma (IFN-,), together with lesser amounts of IFN-,, a unique species of type I IFN. This trophoblastic IFN-, (TrIFN-,) is an unprecedented example of IFN-, being produced spontaneously by an epithelium. We therefore studied some of its structural and biochemical properties, by comparison with pig IFN-, from other sources, either natural LeIFN-, (from adult leucocytes), or recombinant. Biologically active TrIFN-, is a dimeric molecule, of which monomers are mainly composed of a truncated polypeptide chain with two glycotypes, unlike LeIFN-, which is formed of at least two polypeptide chains and four glycotypes. TrIFN-, collected in the uterus lumen was enzymatically deglycosylated and analysed by mass spectrometry (MALDI-TOF). The data revealed that the more abundant polypeptide has a mass of 14.74 kDa, corresponding to a C-terminal cleavage of 17 residues from the expected 143-residue long mature sequence. A minor polypeptide, with a mass of 12.63 kDa, corresponds to a C-terminal truncation of 36 amino acids. MALDI-TOF analysis of tryptic peptides from the glycosylated molecule(s) identifies a single branched carbohydrate motif, with six N -acetylgalactosamines, and no sialic acid. The only glycan microheterogeneity seems to reside in the number of l -fucose residues (one to three). The lack of the C-terminal cluster of basic residues, and the presence of nonsialylated glycans, result in a very low net charge of TrIFN-, molecule. However, the 17-residue truncation does not affect the antiproliferative activity of TrIFN-, on different cells, among which is a porcine uterine epithelial cell line. It is suggested that these specific properties might confer on TrIFN-, a particular ability to invade the uterine mucosa and exert biological functions beyond the endometrial epithelium. [source] Application of Histomorphometric Methods to the Study of Bone Repair,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2005Louis C Gerstenfeld Abstract ABSTRACT: Standardized methods for the histomorphometric assessment of bone are essential features of most studies of metabolic bone diseases and their treatments. These methodologies were developed to assess coupled remodeling, focusing primarily on osteoblasts and osteoclasts, the anabolic and catabolic rates of these cells, and structural features of mature bone. Research studies on bone healing and the development of new therapeutic approaches for the enhancement of bone repair also require a comprehensive understanding of the basic cellular and tissue level mechanisms that underlie these processes. However, the histological methods developed for metabolic bone disease studies are not completely suitable for studies of bone repair because they are based on assumptions that there is little variation in tissue composition within a sample of bone and not generally designed to quantify other types of tissues, such as cartilage, that contribute to bone healing. These techniques also do not provide tissue-based structural measurements that are relatable to the specific types of biomechanical and radiographic structural assessments that are used to determine rates of bone healing. These deficiencies in current histological approaches therefore point to the need to establish standardized criteria for the histomorphometric assessments that are specifically adapted for the study of bone repair in models of fracture healing and bone regeneration. In this Perspective, we outline what we believe to be the specific structural, tissue. and cellular aspects that need to be addressed to establish these standardized criteria for the histomorphometric assessment of bone repair. We present the specific technical considerations that need to be addressed to appropriately sample repair tissues to obtain statistically meaningful results and suggest specific procedures and definitions of nomenclatures for the application of this technology to bone repair. Finally, we present how aspects of histomorphometric measurements of bone repair can be related to biomechanical and radiographic imaging properties that functionally define rates of bone healing, and thus, how these tools can be used to provide corroborating data. [source] Thyrocyte integration, and thyroid folliculogenesis and tissue regeneration: Perspective for thyroid tissue engineeringPATHOLOGY INTERNATIONAL, Issue 6 2001Shuji Toda The thyroid gland is composed of many ball-like structures called thyroid follicles, which are supported by the interfollicular extracellular matrix (ECM) and a capillary network. The component thyrocytes are highly integrated in their specific structural and functional polarization. In conventional monolayer and floating culture systems, thyrocytes cannot organize themselves into follicles with normal polarity. In contrast, in 3-D collagen gel culture, thyrocytes easily form stable follicles with physiological polarity. Integration of thyrocyte growth and differentiation results ultimately in thyroid folliculogenesis. This culture method and subacute thyroiditis are two promising models for addressing mechanisms of folliculogenesis, because thyroid-follicle formation actively occurs both in the culture system and at the regenerative phase of the disorder. The understanding of the mechanistic basis of folliculogenesis is prerequisite for generation of artificial thyroid tissue, which would enable a more physiological strategy to the treatment of hypothyroidism caused by various diseases and surgical processes than conventional hormone replacement therapy. We review here thyrocyte integration, and thyroid folliculogenesis and tissue regeneration. We also briefly discuss a perspective for thyroid tissue regeneration and engineering. [source] Nonadiabatic electron,phonon effects in low carrier density superconductorsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2005E. Cappelluti Abstract Different families of unconventional superconductors present a low charge carrier density as a common trait, suggesting that the low charge density can be at the basis of a unifying picture for different superconductors. In the past years we have suggested that the electron,phonon interaction can be responsible for a high- Tc superconducting pairing in a nonadiabatic regime, where nonadiabatic effects are triggered on by the small electronic Fermi energy associated with the low charge density character. A coherent picture of such a framework requires however reconciling the low charge density and the small Fermi energy with a finite metallic character (sizable density of states and large Fermi surfaces). In this paper we investigate the peculiar conditions which are needed to be encountered in order to fulfill these requirements. We discuss the specific case of fullerenes, cuprates and MgB2 alloys by analyzing their specific structural and electronic properties The comparison between these materials and simple instructive models permits to underline the different routes to reconcile these characteristics in different compounds. In cuprates and fullerenes the interplay between small Fermi energies and large Fermi surface is strictly connected with strong electronic correlation effects. A comprehensive understanding of these issues can be useful to the future search for new nonadiabatic high- Tc materials. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||