bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulin second messengers
Authors: Strålfors Peter 
Published: February 2005

AbstractThe molecular pathways for insulin's signal transduction from its cell surface receptor to the cell's interior metabolic machinery remain in many ways uncharted. Lately two molecules have been proposed as second messengers transducing the insulin signal into the target cell. One is a phospholigosaccharide/inositolphosphoglycan and the other is diacylglycerol, both deriving from the same plasma membrane glycolipid, which is hydrolysed in response to insulin treatment. The phospho‐oligosaccharide appears to mediate many metabolic effects of insulin through control of the phosphorylation state of key regulatory metabolic enzymes. Diacylglycerol may mediate insulin's stimulation of glucose transport over the plasma membrane. The glycolipid precursor of these putative second messengers, as well as the receptor for insulin, appear to be localized in caveolae microdomains of the plasma membrane, and glucose transporters accumulate in caveolae in response to insulin treatment, suggesting a focal role for caveolae in insulin signalling.
The cambrian evolutionary ‘explosion’ recalibrated
Authors: Fortey Richard A. , Briggs Derek E. G. , Wills Matthew A. 
Published: February 2005

AbstractThe sudden appearance in the fossil record of the major animal phyla apparently records a phase of unparalleled, rapid evolution at the base of the Cambrian period, 545 Myr ago. This has become known as the Cambrian evolutionary ‘explosion’, and has fuelled speculation about unique evolutionary processes operating at that time. The acceptance of the palaeontological evidence as a true reflection of the evolutionary narrative has been criticised in two ways: from a reappraisal of the phylogenetic relationships of the early fossils, and from predicitions of molecular divergence times, based on six appropriate metazoan genes. Phylogenetic analysis of the arthropods implies an earlier, Precambrian history for most clades, and hence an extensive period of cladogenesis unrecorded by fossils. A similar argument can be applied to molluscs, lophophorates and deuterostomes. Molecular evidence implies divergence between clades to at least 1000 Myr ago. The apparent paradox between the sudden appearance of recognisable metazoans and their extended evolutionary history might be explained by a sudden Cambrian increase in body size, which was accompanied by skeletisation. A new paradigm suggests that the ‘explosion’ in the record may have been decoupled from the evolutionary innovation.
The IRS‐signalling system during insulin and cytokine action
Authors: Yenush Lynne , White Morris F. 
Published: February 2005

AbstractThe discovery of the first intracellular substrate for insulin, IRS‐1, redirected the field of diabetes research and has led to many important advances in our understanding of insulin action. Detailed analysis of IRS‐1 demonstrates structure/function relationships for this modular docking molecule, including mechanisms of substrate recognition and signal propagation. Recent work has also identified other structurally similar molecules, including IRS‐2, the Drosophila protein, DOS, and the Grb2‐binding protein, Gab1, suggesting that this intracellular signalling strategy is conserved evolutionarily and is utilized by an expanding number of receptor systems. In fact, IRS‐1 itself has been shown to be important in other growth factor and cytokine signalling systems, including growth hormone and several interleukins. Analysis of mice lacking IRS‐1 confirms an important physiological role for this protein in glucose metabolism and general cell growth in the intact animal. Disregulation of the signalling pathways integrated by the IRS proteins may contribute to the pathophysiology of non‐insulin‐dependent diabetes mellitus or other diseases.
Collectins: Collectors of microorganisms for the innate immune system
Authors: Lu Jinhua 
Published: February 2005

AbstractCollections are a group of multimeric proteins mostly consisting of 9–18 polypeptides organised into either ‘bundle‐of‐tulips’ or ‘X‐like’ overall structures. Each polypeptide contains a short N‐terminal segment followed by a collagen‐like sequence and then by a C‐terminal lectin domain. A collectin molecule is assembled from identical or very similar polypeptides by disulphide bonds at the N‐terminal segment, formation of triple helices in the collagen‐like region and clusters of three lectin domains at the peripheral ends of triple helices. These proteins can bind to sugar residues on microorganisms via the peripheral lectin domains and subsequently interact, via the collagen‐like triple‐helices, with receptor(s) on phagocytes and/or the complement system to bring about the killing and clearance of the targets without the involvement of antibodies. The collectins can also bind to phagocyte receptor(s) to enhance phagocytosis mediated by other phagocytic receptors. Lack, or low levels, of collectin expression can lead to higher susceptibility to infections, especially during childhood when specific immunity has not fully developed. Therefore, the collectins play important roles in the enhancement of innate immunity.
The function of inositol high polyphosphate binding proteins
Authors: Fukuda Mitsunori , Mikoshiba Katsuhiko 
Published: February 2005

AbstractThe inositol phosphate metabolism network has been found to be much more complex than previously thought, as more and more inositol phosphates and their metabolizing enzymes have been discovered. Some of the inositol phosphates have been shown to have biological activities, but little is known about their signal transduction mechanisms except for that of inositol 1,4,5‐trisphosphate. The recent discovery, however, of a number of binding proteins for inositol high polyphosphate [inositol 1,3,4,5‐tetrakisphosphate (IP4), inositol 1,3,4,5,6‐pentakisphosphate, or inositol hexakisphosphate] enables us to speculate on the physiological function of these compounds. In this article we focus on two major issues: (1) the roles of inositol high polyphosphates in vesicular trafficking, especially exocytosis, and (2) pleckstrin homology domaincontaining IP4 binding proteins involved in the Ras signaling pathway.
Controlling the molecular motor of neutrophil chemotaxis
Authors: Hallett M. B. 
Published: February 2005

AbstractOur defence against microbes depends largely on the ability of neutrophils to migrate from the blood stream to sites of infection. Although the ability of animal cells to move may be primitive, and also fundamental for a number of phenomena in biology, the cellular mechanism by which neutrophils are able to move rapidly towards the infection remains an enigma. Even though the structures of the receptors involved have been sequenced and many of the molecules involved in neutrophil adherence and traction identified, the essential mechanisms that control and regulate the neutrophil motor remain obscure. Here, an outline of the fundamental inadequacies in our current understanding is given, along with some recent developments that promise to produce some significant advances.
Coxsackieviruses and diabetes
Authors: Ramsingh Arlene I. , Chapman Nora , Tracy Steven 
Published: February 2005

AbstractInsulin‐dependent diabetes mellitus (IDDM) is an autoimmune disease whose etiology is complex. Both genetic susceptibility, which is polygenic, and environmental factors, including virus infections, appear to be involved in the development of IDDM. In this review, we have tried to balance the discussion of diabetes by examining both immunological and virological perspectives. Several mouse models, including viral and non‐viral models, have been used to study diabetes. For this review, we include lessons gleaned from the non‐obese diabetic (NOD) mouse and from mouse models of coxsackievirus‐ and encephalomyocarditis‐virus‐induced diabetes. Finally, we present a multi‐stage model in which several viral infections, including the coxsackieviruses, are postulated to play a role in the autoimmune destruction of pancreatic beta cells.
Complete sequence of a Rhizobium plasmid carrying genes necessary for symbiotic association with the plant host
Authors: Kiss Ernö , Kondorosi Ádám 
Published: February 2005

AbstractThe soil bacteria rhizobia have the capacity to establish nitrogen‐fixing symbiosis with their leguminous host plants. In most Rhizobium species the genes for nodule development and nitrogen fixation have been localized on large indigenous plasmids that are transmissible, allowing lateral transfer of symbiotic functions. A recent paper reports on the complete sequencing of the symbiotic plasmid pNGR234a from Rhizobium species NGR234(1), revealing not only putative new symbiotic genes but also possible mechanisms for evolution and lateral dispersal of symbiotic nitrogen‐fixing abilities among rhizobia.
Vertebrate head induction by anterior primitive endoderm
Authors: Bouwmeester Tewis , Leyns Luc 
Published: February 2005

AbstractIn vertebrates the antero‐posterior organization of the embryonic body axis is thought to result from the activity of two separate centers, the head organizer and the trunk organizer, as operationally defined by Spemann in the 1920s. Current molecular studies have supported the existence of a trunk organizer activity while the presence of a distinct head inducing center has remained elusive. Mainly based on analyses of headless mutants in mice, it has been proposed that the anterior axial mesoderm plays a determining role in head induction. Recent gain‐ and loss‐of‐function studies in various organisms, however, provide compelling evidence that a largely ignored region, the anterior primitive endoderm, specifies rostral identity. In this review we discuss the emerging concept that the anterior primitive endoderm, rather than the prechordal plate mesoderm, induces head development in the vertebrate embryo.
Problems and paradigms: Multifunctional proteins suggest connections between transcriptional and post‐transcriptional processes
Authors: Ladomery Michael 
Published: February 2005

AbstractRecent findings indicate that substantial cross‐talk may exist between transcriptional and post‐transcriptional processes. Firstly, there are suggestions that specific promoters influence the post‐transcriptional fate of transcripts, pointing to communication between protein complexes assembled on DNA and nascent pre‐mRNA. Secondly, an increasing number of proteins appear to be multifunctional, participating in transcriptional and post‐transcriptional events. The classic example is TFIIIA, required for both the transcription of 5S rRNA genes and the packaging of 5S rRNA. TFIIIA is now joined by the Y‐box proteins, which bind DNA (transcription activation and repression) and RNA (mRNA packaging). Furthermore, the tumour suppressor WT1, at first thought to be a typical transcription factor, may also be involved in splicing; conversely, hnRNP K, a bona fide pre‐mRNA‐binding protein, appears to be a transcription factor. Other examples of multifunctional proteins are mentioned: notably PTB, Sxl, La and PU.1. It is now reasonable to assert that some proteins, which were first identified as transcription factors, could just as easily have been identified as splicing factors, hnRNP, mRNP proteins and vice versa. It is no longer appropriate to view gene expression as a series of compartmentalised processes; instead, multifunctional proteins are likely to co‐ordinate different steps of gene expression.
Hypothesis: L‐selectin: A novel receptor for lipopolysaccharide and its potential role in bacterial sepsis
Authors: Malhotra Rajneesh , Bird Michael I. 
Published: February 2005

AbstractThe activation of leukocytes by bacterial cell wall lipopolysaccharide (LPS) contributes to the pathogenesis of septic shock. It is well established that, in the presence of plasma LPS‐binding protein (LBP), LPS binds with high affinity to CD14. The binding of LPS to CD14 has been associated with the activation of cells, although available evidence indicates that CD14 itself does not transduce intracellular signalling. The physiological function of this interaction is to promote host defense mechanisms of cells to combat the infection and clear LPS from the circulation. At higher concentrations of LPS, however, the activation of cells can take place in the absence of LBP and CD14, presumably through a distinct low‐affinity signalling LPS receptor. On the evidence published by us and others, we propose that in neutrophils, and possibly other leukocytes, L‐selectin can act as a low‐affinity LPS receptor.
Zyxin: Zinc fingers at sites of cell adhesion
Authors: Beckerle Mary C. 
Published: February 2005

AbstractZyxin is a low abundance phosphoprotein that is localized at sites of cell‐substratum adhesion in fibroblasts. Zyxin displays the architectural features of an intracellular signal transducer. The protein exhibits an extensive proline‐rich domain, a nuclear export signal and three copies of the LIM motif, a double zinc‐finger domain found in many proteins that play central roles in regulation of cell differentiation. Zyxin interacts with α‐actinin, members of the cysteine‐rich protein (CRP) family, proteins that display Src homology 3 (SH3) domains and Ena/VASP family members. Zyxin and its partners have been implicated in the spatial control of actin filament assembly as well as in pathways important for cell differentiation. Based on its repertoire of binding partners and its behavior, zyxin may serve as a scaffold for the assembly of multimeric protein machines that function in the nucleus and at sites of cell adhesion.
Proliferating cell nuclear antigen: More than a clamp for DNA polymerases
Authors: Jónsson Zophonías O. , Hübscher Ulrich 
Published: February 2005

AbstractDNA metabolic events such as replication, repair and recombination require the concerted action of several enzymes and cofactors. Nature has provided a set of proteins that support DNA polymerases in performing processive, accurate and rapid DNA synthesis. Two of them, the proliferating cell nuclear antigen and its adapter protein replication factor C, cooperate to form a moving platform that was initially thought of only as an anchor point for DNA polymerases δ and ε. It now appears that proliferating cell nuclear antigen is also a communication point between a variety of important cellular processes including cell cycle control, DNA replication, nucleotide excision repair, post‐replication mismatch repair, base excision repair and at least one apoptotic pathway. The dynamic movement of proliferating cell nuclear antigen on and off the DNA renders this protein an ideal communicator for a variety of proteins that are essential for DNA metabolic events in eukaryotic cells.
Multifunctional plasma membrane redox systems
Authors: Medina Miguel Ángel , Castillo‐Olivares Antonio Del , De Castro Ignacio NúÑez 
Published: February 2005

AbstractAll the biological membranes contain oxidoreduction systems actively involved in their bioenergetics. Plasma membrane redox systems seem to be ubiquitous and they have been related to several important functions, including not only their role in cell bioenergetics, but also in cell defense through the generation of reactive oxygen species, in iron uptake, in the control of cell growth and proliferation and in signal transduction. In the last few years, an increasing number of mechanistic and molecular studies have deeply widened our knowledge on the function of these plasma membrane redox systems. The aim of this review is to summarize what is currently known about the components and physiological roles of these systems.
Signaling activation and repression of RNA polymerase II transcription in yeast
Authors: Reece Richard J. , Platt Adam 
Published: February 2005

AbstractActivators of RNA polymerase II transcription possess distinct and separable DNA‐binding and transcriptional activation domains. They are thought to function by binding to specific sites on DNA and interacting with proteins (transcription factors) binding near to the transcriptional start site of a gene. The ability of these proteins to activate transcription is a highly regulated process, with activation only occurring under specific conditions to ensure proper timing and levels of target gene expression. Such regulation modulates the ability of transcription factors either to bind DNA or to interact with the transcriptional machinery. Here we discuss recent advances in our understanding of these mechanisms of transcriptional regulation in yeast.
Calpains: Intact and active?
Authors: Johnson Gail V. W. , Guttmann Rodney P. 
Published: February 2005

AbstractCalpains are a family of calcium‐dependent thiol‐proteases which are proposed to be involved in many physiological processes as well as pathological conditions. Calpains are likely to be involved in processing of numerous enzymes and cytoskeletal components, thereby linking their activity to a variety of intracellular events. Although widely studied, the precise mechanism(s) involved in calpain activation and activity in vivo remain poorly understood. Initial studies suggested that calpain exists primarily as an inactive proenzyme that required autolytic cleavage for activation. It was also hypothesized that calpain associated with membrane phospholipids, serving to increase calcium sensitivity, facilitating autolytic conversion and thus activating the enzyme. These hypotheses, however, have not been universally accepted and there is increasing evidence that intact, non‐autolyzed calpain is the physiologically active calpain form.
Primary rectus abdominis myocutaneous flap for repair of perineal and vaginal defects after extended abdominoperineal resection
Authors: Bell S W , Dehni N , Chaouat M , Lifante J C , Parc R , Tiret E 
Published: February 2005

Abstract

Background
Significant morbidity can result from perineal wounds, particularly after radiotherapy and extensive resection for cancer. Myocutaneous flaps have been used to improve healing. The purpose of this study was to evaluate the morbidity and results of primary rectus abdominis myocutaneous flap reconstruction of the vagina and perineum after extended abdominoperineal resection.

Methods
Thirty-one consecutive patients undergoing one-stage rectus abdominis myocutaneous flap reconstruction of extensive perineal wounds were studied prospectively. Twenty-six patients had surgery for recurrent or persistent epidermoid anal cancer or low rectal cancer, and 21 had high-dose preoperative radiotherapy.

Results
Three weeks after the operation, complete healing of the perineal wound was seen in 27 of the 31 patients. There were nine flap-related complications including three patients with partial flap necrosis, two with vaginal stenosis, one with vaginal scarring, one with small flap disunion and two with weakness of the anterior abdominal wall. There were no unhealed wounds at the completion of follow-up (median 9 months).

Conclusion
The transpelvic rectus abdominis myocutaneous flap for the reconstruction of large perineal and vaginal wounds achieves wound healing with only moderate morbidity in the majority of patients after extensive abdominoperineal resection with or without radiotherapy.
Successful urgent endovascular surgery for symptomatic subclavian artery aneurysmal compression of the trachea
Authors: Bates Mark C. , AbuRahma Ali F. , Crotty Bradley 
Published: February 2005

AbstractThe purpose of this study is to report the progress of a patient who entered the hospital with symptomatic tracheal compression from a large right subclavian artery aneurysm that was treated with a self‐expanding stent graft. The patient was at increased risk for traditional surgery, thus endovascular isolation of the aneurysm was felt to be reasonable. A flexible self‐expanding stent graft was placed via a brachial artery cutdown and common femoral access without complication. The symptoms improved and the patient remained asymptomatic at 2‐year follow‐up with serial CT scan confirmation of aneurysm regression. This unusual case illustrates that endovascular decompression of an aneurysm may have some benefit in alleviating subacute symptoms of extrinsic encroachment into other vital structures. Technical and clinical success was achieved with the stent graft deployment and this seems to be a reasonable alternative to surgery in such patients. Catheter Cardiovasc Interv 2005;64:291–295. © 2005 Wiley‐Liss, Inc.
Rare case of pulmonary arteriovenous fistula simulating residual defect after transcatheter closure of patent foramen ovale for recurrent paradoxical embolism
Authors: Peters Bjoern , Ewert P. , Schubert S. , Abdul‐Khaliq H. , Lange P.E. 
Published: February 2005

AbstractWe report on a patient suffering from recurrent cerebrovascular events despite previous transcatheter closure of persistent foramen ovale (PFO) with a Helex occluder. There was evidence of persistent left‐to‐right atrial shunt shown by transesophageal contrast echocardiography and the patient was admitted to our institution for interventional closure of the supposed residual defect. However, the PFO was completely closed by the device and left pulmonary artery injections showed a pulmonary arteriovenous fistula in the left lower lobe. This rare malformation may well explain the recurrent paradoxical embolism. Transcatheter fistula closure with coils was performed successfully. This case underlines that the existence of an isolated pulmonary arteriovenous fistula as a right‐to‐left shunt in patients with cryptogenic stroke should not be overlooked, even if a PFO is present and pulmonary arteriovenous fistula is not suggested by the initial physical findings or chest X‐ray. Catheter Cardiovasc Interv 2005;64:348–351. © 2005 Wiley‐Liss, Inc.
Submassive pulmonary embolism and paradoxical embolic stroke treated with percutaneous rheolytic thrombectomy and closure of the patent foramen ovale
Authors: Iskander Ayman , Nayak Atasu , Chauhan Manish S. 
Published: February 2005

AbstractThe presence of patent foramen ovale (PFO) in patients with large pulmonary emboli (PE) is associated with an increased risk of stroke and mortality. Many patients are ineligible to receive thrombolytic therapy. We present a patient with bilateral PE and cryptogenic stroke who was treated effectively with rheolytic thrombectomy with AngioJet, PFO closure with CardioSeal device, and placement of an inferior vena cava filter. Catheter Cardiovasc Interv 2005;64:356–360. © 2005 Wiley‐Liss, Inc.