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Complex Pathway (complex + pathway)

Distribution by Scientific Domains

Medical Sciences	66%

Selected Abstracts

Reverse cholesterol transport in type 2 diabetes mellitus

DIABETES OBESITY & METABOLISM, Issue 6 2009
K. C. B. Tan
High-density lipoprotein (HDL) plays an important protective role against atherosclerosis, and the anti-atherogenic properties of HDL include the promotion of cellular cholesterol efflux and reverse cholesterol transport (RCT), as well as antioxidant, anti-inflammatory and anticoagulant effects. RCT is a complex pathway, which transports cholesterol from peripheral cells and tissues to the liver for its metabolism and biliary excretion. The major steps in the RCT pathway include the efflux of free cholesterol mediated by cholesterol transporters from cells to the main extracellular acceptor HDL, the conversion of free cholesterol to cholesteryl esters and the subsequent removal of cholesteryl ester in HDL by the liver. The efficiency of RCT is influenced by the mobilization of cellular lipids for efflux and the intravascular remodelling and kinetics of HDL metabolism. Despite the increased cardiovascular risk in people with type 2 diabetes, current knowledge on RCT in diabetes is limited. In this article, abnormalities in RCT in type 2 diabetes mellitus and therapeutic strategies targeting HDL and RCT will be reviewed. [source]

Structural dynamics of photoinduced molecular switching in the solid state

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 2 2010
Hervé Cailleau
Fast and ultra-fast time-resolved diffraction is a fantastic tool for directly observing the structural dynamics of a material rearrangement during the transformation induced by an ultra-short laser pulse. The paper illustrates this ability using the dynamics of photoinduced molecular switching in the solid state probed by 100,ps X-ray diffraction. This structural information is crucial for establishing the physical foundations of how to direct macroscopic photoswitching in materials. A key feature is that dynamics follow a complex pathway from molecular to material scales through a sequence of processes. Not only is the pathway indirect, the nature of the dynamical processes along the pathway depends on the timescale. This dictates which types of degrees of freedom are involved in the subsequent dynamics or kinetics and which are frozen or statistically averaged. We present a recent investigation of the structural dynamics in multifunctional spin-crossover materials, which are prototypes of molecular bistability in the solid state. The time-resolved X-ray diffraction results show that the dynamics span from subpicosecond molecular photoswitching followed by volume expansion (on a nanosecond timescale) and additional thermoswitching (on a microsecond timescale). [source]

Viewing apoptosis through a ,TUNEL'

THE JOURNAL OF PATHOLOGY, Issue 3 2001
J. A. Walker
Abstract Apoptosis has an important role in carcinogenesis and cancer treatment. The end result of this complex pathway is the formation of apoptotic bodies. These can be difficult to quantify accurately, but quantitation is important if we wish to study this process. Several techniques are available which can help. ,TUNEL' is discussed, with its potential drawbacks, and newer antibody techniques, such as M30 and caspase 3, are then reviewed. Copyright © 2001 John Wiley & Sons, Ltd. [source]

The neuroanatomy and neuroendocrinology of fragile X syndrome

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2004
David Hessl
Abstract Fragile X syndrome (FXS), caused by a single gene mutation on the X chromosome, offers a unique opportunity for investigation of gene,brain,behavior relationships. Recent advances in molecular genetics, human brain imaging, and behavioral studies have started to unravel the complex pathways leading to the cognitive, psychiatric, and physical features that are unique to this syndrome. In this article, we summarize studies focused on the neuroanatomy and neuroendocrinology of FXS. A review of structural imaging studies of individuals with the full mutation shows that several brain regions are enlarged, including the hippocampus, amygdala, caudate nucleus, and thalamus, even after controlling for overall brain volume. These regions mediate several cognitive and behavioral functions known to be aberrant in FXS such as memory and learning, information and sensory processing, and social and emotional behavior. Two regions, the cerebellar vermis, important for a variety of cognitive tasks and regulation of motor behavior, and the superior temporal gyrus, involved in processing complex auditory stimuli, are reported to be reduced in size relative to controls. Functional imaging, typically limited to females, has emphasized that individuals with FXS do not adequately recruit brain regions that are normally utilized by unaffected individuals to carry out various cognitive tasks, such as arithmetic processing or visual memory tasks. Finally, we review a number of neuroendocrine studies implicating hypothalamic dysfunction in FXS, including abnormal activation of the hypothalamic,pituitary,adrenal (HPA) axis. These studies may help to explain the abnormal stress responses, sleep abnormalities, and physical growth patterns commonly seen in affected individuals. In the future, innovative longitudinal studies to investigate development of neurobiologic and behavioral features over time, and ultimately empirical testing of pharmacological, behavioral, and even molecular genetic interventions using MRI are likely to yield significant positive changes in the lives of persons with FXS, as well as increase our understanding of the development of psychiatric and learning problems in the general population. MRDD Research Reviews 2004;10:17,24. © 2004 Wiley-Liss, Inc. [source]

Embryonic stem cells and prospects for their use in regenerative medicine approaches to motor neurone disease

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 5 2007
Y. A. Christou
Human embryonic stem cells are pluripotent cells with the potential to differentiate into any cell type in the presence of appropriate stimulatory factors and environmental cues. Their broad developmental potential has led to valuable insights into the principles of developmental and cell biology and to the proposed use of human embryonic stem cells or their differentiated progeny in regenerative medicine. This review focuses on the prospects for the use of embryonic stem cells in cell-based therapy for motor neurone disease or amyotrophic lateral sclerosis, a progressive neurodegenerative disease that specifically affects upper and lower motor neurones and leads ultimately to death from respiratory failure. Stem cell-derived motor neurones could conceivably be used to replace the degenerated cells, to provide authentic substrates for drug development and screening and for furthering our understanding of disease mechanisms. However, to reliably and accurately culture motor neurones, the complex pathways by which differentiation occurs in vivo must be understood and reiterated in vitro by embryonic stem cells. Here we discuss the need for new therapeutic strategies in the treatment of motor neurone disease, the developmental processes that result in motor neurone formation in vivo, a number of experimental approaches to motor neurone production in vitro and recent progress in the application of stem cells to the treatment and understanding of motor neurone disease. [source]

Processing of CFTR: Traversing the cellular maze,How much CFTR needs to go through to avoid cystic fibrosis?

PEDIATRIC PULMONOLOGY, Issue 6 2005
Margarida D. Amaral PhD
Abstract Biosynthesis of the cystic fibrosis transmembrane conductance regulator (CFTR), like other proteins aimed at the cell surface, involves transport through a series of membranous compartments, the first of which is the endoplasmic reticulum (ER), where CFTR encounters the appropriate environment for folding, oligomerization, maturation, and export from the ER. After exiting the ER, CFTR has to traffic through complex pathways until it reaches the cell surface. Although not yet fully understood, the fine details of these pathways are starting to emerge, partially through identification of an increasing number of CFTR-interacting proteins (CIPs) and the clarification of their roles in CFTR trafficking and function. These aspects of CFTR biogenesis/degradation and by membrane traffic and CIPs are discussed in this review. Following this description of complex pathways and multiple checkpoints to which CFTR is subjected in the cell, the basic question remains of how much CFTR has to overcome these barriers and be functionally expressed at the plasma membrane to avoid CF. This question is also discussed here. Pediatr Pulmonol. © 2005 Wiley-Liss, Inc. [source]