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At least 631 records · Page 35Linked to original sources

PubMed1993

Capsular tissue: a new local flap.

Capsular tissue, the interface that forms between an implanted device and the body's own soft tissues, has recently been shown to develop its own unique blood supply. This capsular tissue with its extensive vascular plexus has not been described previously as an isolated flap. The purpose of our study was to determine whether an isolated flap of capsular tissue would survive as a local pedicle flap and provide enough inherent vascularity to support a skin graft. Isolated expanded and nonexpanded capsular flaps were compared by using 20 expanders (10 expanded and 10 nonexpanded) in two mixed-breed female pigs. Expanded and nonexpanded capsular flaps were elevated 8 weeks following expander placement. These flaps were raised on their capsular bases alone, and skin grafts were placed onto the capsular surfaces. All the expanded capsular flaps and their skin grafts had 100 percent survival. Skin grafts on the nonexpanded flaps survived an average of 28 percent, with graft survival corresponding to flap survival. This study confirms that flaps of isolated expanded capsular tissue survive and provide enough inherent vascularity to support a split-thickness skin graft.

Animals↗

PubMed1991

Structure of porcine insulin cocrystallized with clupeine Z.

The crystal structure of NPH-insulin, pig insulin cocrystallized with zinc, m-cresol and protamine, has been solved by molecular replacement and refined using restrained least-squares refinement methods. The final crystallographic R factor for all reflections between 2 and 10 A is 19.4%. The insulin molecules are arranged as hexamers with two tetrahedrally coordinated Zn atoms in the central channel and one m-cresol bound to each monomer near His B5. One protamine binding site has been unequivocally identified near a dimer-dimer interface, although most of the polypeptide is crystallographically disordered. The conformation of the insulin moiety and the structural differences between the three unique monomers have been analysed. The zinc and m-cresol environments are described and the nature of the protamine binding site is outlined.

Animals↗

PubMed1987

The primary structures of the major and minor hemoglobin-components of adult Andean goose (Chloephaga melanoptera, Anatidae): the mutation Leu----Ser in position 55 of the beta-chains.

The primary structures of the hemoglobin components Hb A and Hb D of the adult Andean Goose (Chloephaga melanoptera) are presented. The globin chains were separated on CM-Cellulose in 8M urea buffer. The amino-acid sequences were established by automatic Edman degradation of the globin chains and of the tryptic peptides in liquid- and gas-phase sequenators. The sequences are aligned with those of Greylag Goose (Anser anser) as a biological reference and other sequences of birds. A detailed evaluation of all residues of Andean Goose hemoglobins on the basis of the 12000 known avian globin sequences leads to a molecular pattern for high-altitude respiration of geese. The replacement of functional and structural importance is the unique occurrence of the residue beta 55 Leu----Ser (all other exchanges are functionally neutral), interrupting the same alpha 1 beta 1-interface contact (alpha 119-beta 55) that accounts for high-altitude respiration of the Barheaded Goose (Anser indicus); there the mutation is found on alpha A 119. Loosening the constraints of this interface must be interpreted as a destabilization of the low-affinity T-structure in favour of the high-affinity R-structure. The structural and functional significance of this interface for the molecular biology of high-altitude respiration of the Andean Goose and Barheaded Goose is discussed. Since Hb A consists of alpha A2 beta 2 and Hb D consists of alpha D2 beta 2 the mutation occurring in blood of the Andean Goose affects both hemoglobins whereas in the case of the Barheaded Goose only Hb A is affected. These results show that Hb D can be considered a biological reserve to enlarge situatively the normal hemoglobin function. A general molecular pattern for permanent (selective advantage of high intrinsic oxygen affinity) and transitory (selective advantage of graded oxygen affinities) adaptation to hypoxia is discussed. A survey on the sequence homology of the globin chains of geese (Anserinae) and ducks (Anatinae) is given.

Altitude↗

PubMed2002

[Kudo non-constrained elbow prosthesis for inflammatory and hemophilic joint disease: analysis in 30 cases].

PURPOSE OF THE STUDY: We analyzed retrospectively 30 Kudo non-constrained elbow prostheses to determine: 1) functional outcome and mobility, 2) frequency of loosening and any complications. MATERIAL AND METHODS: From 1992 to 1998, 30 Kudo total elbow arthroplasties were performed in 29 patients, mean age 55 years. Mean follow-up was 36 months. These patients had severe joint disease: rheumatoid arthritis for 24, psoriatic arthritis for 2, and hemophilic arthritis for 3. The 29 patients experienced severe pain before surgery. RESULTS: At review, 21 elbows were pain free and the 9 others had only occasional pain. Among these 9 elbows, 3 exhibited a rupture of the humeral implant; one had already been revised but remained painful. One patient had a stiff painful elbow after reflex dystrophy and five others had pain but no other complication. Twenty-six patients were satisfied or very satisfied. Three patients were unsatisfied because of the humeral implant fracture. Mean mobility at last follow-up was: 128 degrees flexion, -35 degrees extension, 72 degrees pronation, and 74 degrees supination. Mean gain in flexion-extension was 15 degrees and mean gain in pronosupination was 3 degrees. Pronosupination was greater than 100 degrees except for two patients. There was one immediate post-operative dislocation with failure of prolonged orthopedic treatment after reduction; this patient underwent revision reconstruction with repair of the ulnar collateral ligaments (plasty of the medial collateral ligament with a synthetic ligament). Painful movement of the radial stump was observed with one Kudo prosthesis and required resection to achieve cure. In all, there were 3 fractures of the Kudo I prosthesis at the junction of the trochlea and the humeral stem. Among these patients, one underwent revision due to persistent pain, and two others with currently acceptable symptoms are awaiting revision. At last follow-up, we had: 1 ulnar loosening associated with cortical thinning facing the end of the ulnar implant that had migrated and showed a circular lucent line measuring > 1 mm and progressing; 9 unique ulnar lucent lines measuring<1 mm without progression at the proximal part of the implant (6 at the bone-cement interface and 3 at the bone-implant interface); 3 humeral radiolucent lines (<1 mm without progression) on the distal part of the Kudo II humeral stems corresponding to a zone without surfacing. We also observed 13 cases of incomplete ossification between the humerus and ulna and among these 13, 7 elbows had amplitudes of less than 100 degrees. DISCUSSION AND CONCLUSION: Elbow arthroplasty can restore a painless joint and maintain or improve elbow motion. The procedure is indicated when the joint disease impair daily life activities. Final mobility basically depends on the preoperative mobility. The bone stock remains the greatest problem with these resurfaced prostheses. The GUEPAR elbow prosthesis would appear to be more adapted due to the reconstruction of the trochlea. Resection of the radial head is a source of instability for elbow prostheses and should lead to the design of three-compartment prostheses.

Activities of Daily Living↗

PubMed1989

The use of soot analysis as an investigative tool in aircraft fires.

Traditionally, carboxyhemoglobin analysis has been used to determine the extent of respiration during a postcrash fire. This is a useful and informative measurement, but advances in the chemical analysis of soot samples provide a new and useful forensic tool for the investigation of deaths by fire. One of the latest analytical techniques is a computer-interfaced pyrolysis mass spectrometry. Soot consists of a high percentage of carbon as well as fragments of the original polymer that are unique to that particular material. Consequently, analysis and identification of the fragment pattern makes it possible to identify the original material from which the soot was generated. In pyrolysis mass spectrometry the soot is pyrolyzed into the ion source and the resulting ion pattern is computer analyzed to identify the polymeric system or systems that generated the soot. Analysis of soot samples collected from the upper respiratory tract of aircraft accident victims and from the accident scene can provide information on the type of toxic insult (identifies specific toxic products), the material(s) that burned and generated the toxic atmosphere, and the relative time of survival following the crash. This technique has been applied to the investigation of fire deaths in a hotel fire and will be used to illustrate the identification of the materials that burned, the toxic products, and the potential for aircraft accident investigations.

Accidents, Aviation↗

PubMed1996

In vitro modeling of the bone/implant interface.

BACKGROUND: The purpose of this review is to examine the usefulness of cell culture methods to model the mechanisms of bone formation on the surfaces of candidate implant materials. METHODS: The central objective is to show that in vitro methods are uniquely valuable in providing an understanding of how new bone is formed on solid surfaces. It should be emphasized, at the outset, that the use of cell culture studies as cytotoxicity assays will not be addressed, nor is it implied that cell cultures can model all the complexities of the in vivo environment. Nevertheless, by comparison with in vivo data, which are by nature retrospective, it is shown that primary differentiating osteogenic cell cultures, derived from bone marrow, illustrate a sequence of extracellular matrix elaboration events that characterize the establishment of the interface between newly formed bone and solid surfaces. These solid surfaces either may be implant materials, or indeed previously formed bone matrix, which has been resorbed during normal bone remodeling events. In each case the first biologically derived matrix at these sites is a morphologically distinct collagen fibre-free extracellular matrix, which, in bone histology has been referred to for > 100 years as a cement line. RESULTS: The sequence starts with secretion and adsorption to the substratum of organic components, of which the major proteins are osteopontin and bone sialoprotein. Mineralization of this matrix occurs by the seeding of nanocrystalline calcium phosphate, which precedes the appearance of morphologically identifiable collagen fibres. This is clearly contrary to the dogma that collagen is necessary for mineralization of bone, but is in agreement with specific cases of other, particularly dental, calcified connective tissues. Although collagen is synthesized by the differentiating osteogenic cells that elaborate the cement line interface, it is not adsorbed to the underlying solid surface. Following the elaboration of the cement line matrix, collagen fibre assembly occurs and is then mineralized to produce morphologically identifiable bone matrix. CONCLUSION: Key elements of this sequence of events can be seen at the interface of implants retrieved from in vivo experiments, which indicates that these in vitro methods not only mimic known in vivo phenomena, but also provide a mechanistic understanding of bone elaboration at implant surfaces. However, distinction is drawn between the events of new bone formation at implant surfaces and other bone/implant morphologies, which are unrelated to de novo bone formation at the implant surface. Finally, this new information emerging from bone marrow cell culture studies demands a re-examination of the concepts of bone-bonding and nonbonding implant materials.

Adult↗

PubMed2006

Flow modulation comprehensive two-dimensional gas chromatography-mass spectrometry with a supersonic molecular beam.

A new approach of flow modulation comprehensive two-dimensional gas chromatography-mass spectrometry (GC x GC-MS) with supersonic molecular beam (SMB) and a quadrupole mass analyzer is presented. Flow modulation uniquely enables GC x GC-MS to be achieved even with the limited scan speed of quadrupole MS, and its 20 ml/min column flow rate is handled, splitless, by the SMB interface. Flow modulation GC x GC-SMB-MS shares all the major benefits of GC x GC and combines them with GC-MS including: (a) increased GC separation capability; (b) improved sensitivity via narrower GC peaks; (c) improved sensitivity through reduced matrix interference and chemical noise; (d) polarity and functional group sample information via the order of elution from the second polar column. In addition, GC x GC-SMB-MS is uniquely characterized by the features of GC-MS with SMB of enhanced and trustworthy molecular ion plus isotope abundance analysis (IAA) for improved sample identification and fast fly-through ion source response time. The combination of flow modulation GC x GC with GC-MS with SMB (supersonic GC-MS) was explored with complex matrices such as diesel fuel analysis and pesticide analysis in agricultural products.

Chromatography, Gas↗

PubMed2005

In situ synthesis of temperature-sensitive hollow microspheres via interfacial polymerization.

In this communication, a novel one-pot synthetic strategy for preparing hollow PNIPAM microspheres via an interfacial polymerization approach at the interface of an inverse W/O emulsion has been proposed and demonstrated. The results show that the prepared PNIPAM microspheres have real empty core and polymer shell structure, with a size range of 1-3 mum. The hollow microspheres experienced a reversible swelling and deswelling process by mediating the temperature below and above the lower critical solution temperature (LCST) of the PNIPAM. The new approach not only provided a unique technical pathway to prepare hollow PNIPAM microspheres in situ under mild reaction conditions but also opened a platform for helping to understand the mechanism of diffusion, migration of the PNIPAM at an oil/water interface above its LCST, and the polymer layer formation mechanism as well.

Acrylic Resins↗

PubMed2006

CardioSignal: a database of transcriptional regulation in cardiac development and hypertrophy.

BACKGROUND: Although extensive research has characterized intricate genetic programs in heart system, the information generated is highly fragmented. Here we have developed a new database called CardioSignal, which was designed for integration of regulatory information on the transcriptional regulation involved in heart development and cardiac hypertrophy. METHODS: Data about sequences, positions and functional annotation of transcription binding sites, cis-regulatory modules as well as promoters were collected from scientific literature. Genes involved in both processes were also manually gathered, particularly those preferentially expressed in the heart. Data was stored in MySQL database and Perl was used as the server-side programming language. RESULTS: Currently, CardioSignal contains 677 cardiac genes from twenty species. Among them are 128 cardiac transcription factors. Of the approximately 179 individual promoters from six species, the database also documented 247 experimentally verified binding sites and 64 cis-regulatory modules. CardioSignal may be searched for the promoter of a specific gene by specifying a gene name, Entrez geneID, swissProt accession number and so on. Downstream targets of transcriptional factors and cardiac regulatory modules can also be retrieved through a user-friendly web interface. Also available is experimental supporting evidence. Computational analysis tools were implemented for on-the-fly motif finding and comparative genomic analysis respectively. CONCLUSIONS: CardioSignal offers a unique resource as it contains simultaneously the promoter collected while correlating the information of transcription factor binding sites and cis-regulatory modules from heart system. We are hopeful that its implementation will contribute toward the elucidation of the complex processes in cardiac development and hypertrophy.

Animals↗

PubMed2005

Establishment of epidermal cell lines derived from the skin of the Atlantic bottlenose dolphin (Tursiops truncatus).

The Atlantic bottlenose dolphin (Tursiops truncatus), a marine mammal found off the Atlantic coast, has become the focus of considerable attention because of an increasing number of mortality events witnessed in this species over the last several years along the southeastern United States. Assessment of the impact of environmental stressors on bottlenose dolphins (BND) has been difficult because of the protected status of these marine mammals. The studies presented herein focused on establishing epidermal cell cultures and cell lines as tools for the in vitro evaluation of environmental stressors on BND skin. Epidermal cell cultures were established from skin samples obtained from Atlantic BND and subjected to karyotype analysis. These cultures were further characterized using immunohistochemical methods demonstrating expression of cytokeratins. By two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), we observed that the proteomic profile of BND skin tissue samples shared distinct similarities with that of skin-derived cultures. Epidermal cell cultures were transfected with a plasmid encoding the SV40 small t- and large T-antigens, as well as the neomycin-resistance gene. Five neomycin-resistant clones were isolated and expanded, and all of them proliferated at a faster rate than nontransfected BND epidermal cultures, which exhibited signs of senescence. Cell lysates prepared from two transfected clones were shown to express, by Western blot analysis, both SV40 tumor antigens. These experimental results are consistent with the concept that transfected clones expressing SV40 tumor antigens represent immortalized BND cell lines. Epidermal cell lines derived from Tursiops truncatus will provide a unique tool for studying key features of the interaction occurring between dolphins and the environment in which they live at their most crucial interface: the skin.

Animals↗

PubMed2002

IMGT gene identification and Colliers de Perles of human immunoglobulins with known 3D structures.

A new database, IMGT/3Dstructure-DB, was developed and implemented in the IMGT (international ImMunoGeneTics database) information system (http://imgt.cines.fr) to provide a unique expertised resource on immunoglobulin and T-cell receptor structural data. Corresponding protein sequences were annotated with IMGT tools, which allow the precise identification of the genes expressed in these proteins, and the description of framework and complementarity determining regions according to the IMGT standardized nomenclature and IMGT unique numbering. Two-dimensional graphical representations of the V-DOMAINs, designated as Colliers de Perles, are automatically produced. A query Web interface allows interactive search of the IMGT/3D structure-DB data. In this article, IMGT gene identification and Colliers de Perles of human immunoglobulins with known 3D structures in the Protein Data Bank are presented.

Alleles↗

PubMed1996

A comparison of the surface activity of the fungal hydrophobin SC3p with those of other proteins.

The fungal hydrophobin SC3p, a protein secreted by Schizophyllum commune, has become known to form SDS-insoluble layers and to change the physico-chemical properties of an interface. In this study, the surface activity of SC3p was studied by determining the interfacial tensions gamma iv and gamma sl during adsorption of SC3p at both the liquid-vapour and the solid-liquid interface utilizing the in situ technique axisymmetric drop-shape analysis by profile. To this end, protein solution droplets were put on the solid fluoroethylene-propylene-Teflon. At the liquid-vapour interface, SC3p caused a large decrease of gamma iv from 72 to 43 mJ m-2 at the concentration of 0.1 mg ml-1. At the solid-liquid interface, gamma sl was slightly decreased, whereas the contact angle theta increased, indicating an increase in hydrophobicity of FEP-Teflon, which is unique among the proteins studied so far. Earlier findings indicated a decrease in hydrophobicity of Teflon upon adsorption of SC3p, but this was after a washing and drying step. In order to reconcile these findings with those of the present study, adsorption of SC3p to hydrophobic surfaces is suggested to occur in bilayers. The second layer is supposed to be less strongly adsorbed than the first layer and can be easily removed by washing.

Adsorption↗

PubMed2000

Crystal structure of human branched-chain alpha-ketoacid dehydrogenase and the molecular basis of multienzyme complex deficiency in maple syrup urine disease.

BACKGROUND: Mutations in components of the extraordinarily large alpha-ketoacid dehydrogenase multienzyme complexes can lead to serious and often fatal disorders in humans, including maple syrup urine disease (MSUD). In order to obtain insight into the effect of mutations observed in MSUD patients, we determined the crystal structure of branched-chain alpha-ketoacid dehydrogenase (E1), the 170 kDa alpha(2)beta(2) heterotetrameric E1b component of the branched-chain alpha-ketoacid dehydrogenase multienzyme complex. RESULTS: The 2.7 A resolution crystal structure of human E1b revealed essentially the full alpha and beta polypeptide chains of the tightly packed heterotetramer. The position of two important potassium (K(+)) ions was determined. One of these ions assists a loop that is close to the cofactor to adopt the proper conformation. The second is located in the beta subunit near the interface with the small C-terminal domain of the alpha subunit. The known MSUD mutations affect the functioning of E1b by interfering with the cofactor and K(+) sites, the packing of hydrophobic cores, and the precise arrangement of residues at or near several subunit interfaces. The Tyr-->Asn mutation at position 393-alpha occurs very frequently in the US population of Mennonites and is located in a unique extension of the human E1b alpha subunit, contacting the beta' subunit. CONCLUSIONS: Essentially all MSUD mutations in human E1b can be explained on the basis of the structure, with the severity of the mutations for the stability and function of the protein correlating well with the severity of the disease for the patients. The suggestion is made that small molecules with high affinity for human E1b might alleviate effects of some of the milder forms of MSUD.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗

PubMed2002

Anti-p200 pemphigoid: diagnosis and treatment of a case presenting as an inflammatory subepidermal blistering disease.

Anti-p200 pemphigoid is a recently defined subepidermal immunobullous disease. It is characterized by the binding of circulating IgG autoantibodies to the dermal side of 1 M NaCl split skin and by reactivity of these autoantibodies to a unique 200-kd antigen on immunoblot of dermal extract. On immunoelectron microscopic examination, these autoantibodies deposit at the lamina lucida-lamina densa interface. We describe the clinical, histologic, and immunopathologic features in a patient with anti-p200 pemphigoid, as well as his favorable response to treatment with systemic glucocorticosteroids and dapsone.

Autoantibodies↗

PubMed2001

Adaptation of Arctic and Antarctic ice metazoa to their habitat.

Sea ice is a unique habitat in polar seas. A diverse assemblage of plants and animals lives in its interior parts and at the ice-water interface. Their distribution is to a large extent controlled by abiotic parameters such as light, salinity and space, as well as food availability. In both the Arctic and Antarctic, the highest metazoan concentrations occur mostly in the bottom centimetres of the sea ice. Dominant metazoans are nematodes, turbellarians, rotifers and crustaceans. The ice-water interface itself houses in addition to endemic amphipods migrants from both the ice and the pelagic realm. To survive with the environmental conditions of the sea ice habitat, the ice biota is adapted, specifically to seasonal salinity variations from below 5 to above 60 PSU. Sea ice metazoans feed mainly on the algae growing within the sea ice. The loss of habitat during ice melt periods can lead to substantial sedimentation of ice fauna to the sea floor, where it might act as food source for the benthos.

Journal Article↗

PubMed1997

Analysis of bark proteins in blister rust-resistant and susceptible western white pine (Pinus monticola).

We compared bark proteins from four contrasting (blister rust-resistant versus susceptible) half-sib seedling pairs of western white pine (Pinus monticola D. Don). Pooled proteins from resistant and susceptible groups (four trees per group) were separated by two-dimensional gel electrophoresis, silver stained, and analyzed with the aid of a laser scanner interfaced with a computerized gel documentation system. Qualitative and quantitative protein differences were observed between resistant and susceptible groups. The number of proteins unique to a group was greater in the susceptible category than in the resistant category. Biosynthesis of some common proteins was enhanced near lesioned areas of susceptible seedlings. Many proteins shared similar charge and mass characteristics with those of pathogenesis-related (PR) proteins. Two protein bands were isolated and partially characterized by N-terminal amino acid sequencing: a 10.6-kDa band that was selectively enriched in all resistant individuals, and a 26.0-kDa band that was enriched in some susceptible individuals. The significance of these protein differences and the possible use of selected proteins as disease or resistance markers are discussed.

Journal Article↗

PubMed1995

The cystine-knot growth-factor superfamily.

Four recent crystal structures of growth factors--nerve growth factor, transforming growth factor-beta, platelet-derived growth factor, and human chorionic gonadotropin--from four separate superfamilies revealed that these proteins are structurally related and share a common overall topology. These proteins have very little sequence homology, but they all have an unusual arrangement of six cysteines linked to form a "cystine-knot" conformation. The active forms of these proteins are dimers, either homo- or heterodimers. Despite the overall topological similarity between the monomers, the interfaces used to form the dimer are in each case quite different. Because the surfaces used for dimer formation are mostly hydrophobic, the uniqueness of each dimer accounts for the lack of sequence homology and raises questions about the effectiveness of reverse sequence fitting in this kind of structure as a predictor of structural homology.

Becaplermin↗

PubMed2006

The physiological function of the urothelium--more than a simple barrier.

The urothelium, the epithelium lining the surface of the urinary bladder, is a unique cell type with high plasticity and a variety of cellular functions. The urothelium represents the first line of bladder defense and an interface between pathogens and defense mechanisms. Functions of the urothelium include control of permeability, immune responses and cell-cell communication, which seems to play a pivotal role in responding to injuries and infections. The urothelium responds to stretch, during the filling phase of micturition reflex, by increasing the size of apical umbrella cells and by releasing mediators which activate the sensory fibers. For this reason the concept of 'neuron-like properties' was suggested. Finally, despite the fact that the urothelium is a frequent site of cancer formation, few experimental model systems are currently available or well characterized for studying urothelial cancer in the era of genomics and proteomics. The purpose of this review is to give emphasis to urothelial physiology and pathophysiology in different bladder disorders and to offer an up-to-date contribution to the field of urothelial research.

Animals↗