SEARCH · PubMed Health

Results for “PROST”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources

PubMed2006

Negative tension induced by lipid uptake.

Membrane fusion is an important process in cell biology. While the molecular mechanisms of fusion are actively studied at a very local scale, the consequences of fusion at a larger scale on the shape and stability of the membrane are still not explored. In this Letter, the evolution of the membrane tension during the fusion of positive small unilamellar vesicles with a negative giant unilamellar vesicle has been experimentally investigated and compared to an existing theoretical model. The tension has been deduced using videomicroscopy from the measurement of the fluctuation spectrum and of the time correlation function of the fluctuations. We show that fusion induces a strong decrease in the effective tension of the membrane which eventually reaches negative values. Under these conditions, we show that localized instabilities appear on the vesicle. The membrane finally collapses, forming dense lipid structures.

Algorithms↗

PubMed2005

Evaluation of the antimicrobial activities of plant oxylipins supports their involvement in defense against pathogens.

Plant oxylipins are a large family of metabolites derived from polyunsaturated fatty acids. The characterization of mutants or transgenic plants affected in the biosynthesis or perception of oxylipins has recently emphasized the role of the so-called oxylipin pathway in plant defense against pests and pathogens. In this context, presumed functions of oxylipins include direct antimicrobial effect, stimulation of plant defense gene expression, and regulation of plant cell death. However, the precise contribution of individual oxylipins to plant defense remains essentially unknown. To get a better insight into the biological activities of oxylipins, in vitro growth inhibition assays were used to investigate the direct antimicrobial activities of 43 natural oxylipins against a set of 13 plant pathogenic microorganisms including bacteria, oomycetes, and fungi. This study showed unequivocally that most oxylipins are able to impair growth of some plant microbial pathogens, with only two out of 43 oxylipins being completely inactive against all the tested organisms, and 26 oxylipins showing inhibitory activity toward at least three different microbes. Six oxylipins strongly inhibited mycelial growth and spore germination of eukaryotic microbes, including compounds that had not previously been ascribed an antimicrobial activity, such as 13-keto-9(Z),11(E),15(Z)-octadecatrienoic acid and 12-oxo-10,15(Z)-phytodienoic acid. Interestingly, this first large-scale comparative assessment of the antimicrobial effects of oxylipins reveals that regulators of plant defense responses are also the most active oxylipins against eukaryotic microorganisms, suggesting that such oxylipins might contribute to plant defense through their effects both on the plant and on pathogens, possibly through related mechanisms.

Anti-Infective Agents↗

PubMed2000

AINTEGUMENTA promotes petal identity and acts as a negative regulator of AGAMOUS.

The Arabidopsis AINTEGUMENTA (ANT) gene has been shown previously to be involved in ovule development and in the initiation and growth of floral organs. Here, we show that ANT acts in additional processes during flower development, including repression of AGAMOUS (AG) in second whorl cells, promotion of petal epidermal cell identity, and gynoecium development. Analyses of ap2-1 ant-6 double mutants reveal that ANT acts redundantly with AP2 to repress AG in second whorl cells. The abaxial surface of ant petals contains features such as stomata and elongated, interdigitated cells that are not present on wild-type petals. The loss of petal identity in these second whorl cells does not result from ectopic AG expression, suggesting that ANT acts in a pathway promoting petal cell identity that is independent of its role in repression of AG. These data suggest that ANT may function as a class A gene.

AGAMOUS Protein, Arabidopsis↗

PubMed2003

Nonseparable wavelet-based cone-beam reconstruction in 3-D rotational angiography.

In this paper, we propose a new wavelet-based reconstruction method suited to three-dimensional (3-D) cone-beam (CB) tomography. It is derived from the Feldkamp algorithm and is valid for the same geometrical conditions. The demonstration is done in the framework of nonseparable wavelets and requires ideally radial wavelets. The proposed inversion formula yields to a filtered backprojection algorithm but the filtering step is implemented using quincunx wavelet filters. The proposed algorithm reconstructs slice by slice both the wavelet and approximation coefficients of the 3-D image directly from the CB projection data. The validity of this multiresolution approach is demonstrated on simulations from both mathematical phantoms and 3-D rotational angiography clinical data. The same quality is achieved compared with the standard Feldkamp algorithm, but in addition, the multiresolution decomposition allows to apply directly image processing techniques in the wavelet domain during the inversion process. As an example, a fast low-resolution reconstruction of the 3-D arterial vessels with the progressive addition of details in a region of interest is demonstrated. Other promising applications are the improvement of image quality by denoising techniques and also the reduction of computing time using the space localization of wavelets.

Algorithms↗

PubMed2002

Continuous time transfer using GPS carrier phase.

The Astronomical Institute of the University of Berne is hosting one of the Analysis Centers (AC) of the International GPS Service (IGS). A network of a few GPS stations in Europe and North America is routinely analyzed for time transfer purposes, using the carrier phase observations. This work is done in the framework of a joint project with the Swiss Federal Office of Metrology and Accreditation (METAS). The daily solutions are computed independently. The resulting time transfer series show jumps of up to 1 ns at the day boundaries. A method to concatenate the daily time transfer solutions to a continuous series was developed. A continuous time series is available for a time span of more than 4 mo. The results were compared with the time transfer results from other techniques such as two-way satellite time and frequency transfer. This concatenation improves the results obtained in a daily computing scheme because a continuous time series better reflects the characteristics of continuously working clocks.

Calibration↗

PubMedDate not supplied

Wavelet-based multiresolution analysis of irregular surface meshes.

This paper extends Lounsbery's multiresolution analysis wavelet-based theory for triangular 3D meshes, which can only be applied to regularly subdivided meshes and thus involves a remeshing of the existing 3D data. Based on a new irregular subdivision scheme, the proposed algorithm can be applied directly to irregular meshes, which can be very interesting when one wants to keep the connectivity and geometry of the processed mesh completely unchanged. This is very convenient in CAD (Computer-Assisted Design), when the mesh has attributes such as texture and color information, or when the 3D mesh is used for simulations, and where a different connectivity could lead to simulation errors. The algorithm faces an inverse problem for which a solution is proposed. For each level of resolution, the simplification is processed in order to keep the mesh as regular as possible. In addition, a geometric criterion is used to keep the geometry of the approximations as close as possible to the original mesh. Several examples on various reference meshes are shown to prove the efficiency of our proposal.

Algorithms↗

PubMedDate not supplied

Wavelet-based progressive compression scheme for triangle meshes: wavemesh.

This paper proposes a new lossy to lossless progressive compression scheme for triangular meshes, based on a wavelet multiresolution theory for irregular 3D meshes. Although remeshing techniques obtain better compression ratios for geometric compression, this approach can be very effective when one wants to keep the connectivity and geometry of the processed mesh completely unchanged. The simplification is based on the solving of an inverse problem. Optimization of both the connectivity and geometry of the processed mesh improves the approximation quality and the compression ratio of the scheme at each resolution level. We show why this algorithm provides an efficient means of compression for both connectivity and geometry of 3D meshes and it is illustrated by experimental results on various sets of reference meshes, where our algorithm performs better than previously published approaches for both lossless and progressive compression.

Algorithms↗

PubMed1997

Bullous pemphigoid and cicatricial pemphigoid autoantibodies react with ultrastructurally separable epitopes on the BP180 ectodomain: evidence that BP180 spans the lamina lucida.

The BP180 antigen is a hemidesmosomal glycoprotein that is recognized by autoantibodies associated with three autoimmune disorders, bullous pemphigoid (BP), herpes gestationis (HG), and cicatricial pemphigoid (CP). BP and HG sera have been shown to recognize a common extracellular site located near the membrane-spanning domain of this protein, whereas CP sera react predominantly with a distinct site near the C terminus. In the current study, the main immunogenic sites on the BP180 ectodomain were ultrastructurally localized using six BP sera, four CP sera, and two rabbit antisera. The immunolocalization pattern of BP sera was largely restricted to the upper lamina lucida region immediately subjacent to the epidermal hemidesmosome and closely resembled that of a rabbit antiserum directed against the NC16A (membrane-proximal) domain of BP180. CP sera, on the other hand, exhibited a lower lamina lucida/lamina densa labeling pattern that was strikingly similar to that of rabbit antibodies to the BP180 C-terminal region. Finally, antibodies to the BP180 C-terminal region co-localized with an anti-laminin-5 antibody in the anchoring filament zone. These findings strongly suggest that the BP180 extracellular domain exists in an extended conformation, with the C terminus of this protein projecting into the lamina densa. These data support the hypothesis that BP180 contributes to the structure and function of the anchoring filaments. Differences in the ultrastructural mapping of BP and CP autoantibodies appear to correlate with epitope mapping data, which, together, may help to explain the clinical heterogeneity observed in this group of bullous disorders.

Actin Cytoskeleton↗

PubMed1996

Cicatricial pemphigoid autoantibodies react with multiple sites on the BP180 extracellular domain.

Cicatricial pemphigoid (CP) is an autoimmune blistering disease that primarily affects mucosal tissues. Autoantibodies to laminin-5 have previously been detected in certain patients with a CP-like disease; however, individuals that exhibit this reactivity profile apparently represent a small subset of CP patients. In the present investigation, 0 of 18 CP sera showed reactivity with laminin-5 by immunoblotting. In contrast, 18 of 23 CP sera (78%) recognized a 180-kDa epidermal antigen that, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, co-migrated with BP180, a hemidesmosomal glycoprotein associated with two other autoimmune blistering diseases, bullous pemphigoid and herpes gestationis. To investigate further the CP autoimmune response, various segments of human BP180 were expressed as bacterial fusion proteins and assayed by immunoblotting for reactivity with CP patients' sera. The results of this investigation demonstrated that the BP180 autoantigen is indeed a major target of CP autoantibodies. Further, two distinct CP-reactive sites were identified on the extracellular domain of the BP180 protein, one located in the non-collagenous (NC) 16A domain (at or near the previously defined autoantibody-reactive site recognized by bullous pemphigoid and herpes gestationis sera) and the other in the carboxy-terminal region of this protein. Sixteen of 23 CP sera (70%) reacted with one or both of these antigenic sites of BP180. Other immunologic data suggested that BP180 may harbor additional CP-reactive sites. In conclusion, there are now three bullous diseases, bullous pemphigoid, herpes gestationis, and cicatricial pemphigoid, that are known to be associated with an autoimmune response against the extracellular domain of the BP180 antigen.

Aged↗

PubMed1994

Overlapping distribution of autoantibody specificities in paraneoplastic pemphigus and pemphigus vulgaris.

Paraneoplastic pemphigus is an autoimmune bullous skin disease in which autoantibodies immunoprecipitate a characteristic antigenic complex. The objective of this study was to analyze by immunoblotting and immunoelectron microscopy the autoimmune response in five patients with clinical and immunohistologic features typical of paraneoplastic pemphigus. In a first series of experiments, immunoblotting and immunoelectron microscopy were performed using anti-human whole Ig. Although immunoblotting results were consistent with the autoantibody specificities previously described in paraneoplastic pemphigus sera, immunoelectron microscopy demonstrated the presence of Ig deposits on desmosomal plaques, on hemidesmosomes and, surprisingly, on both the extracellular part of desmosomes and the keratinocyte plasma membrane. In a second series of experiments, immunoblotting and immunoelectron microscopy were carried out using antihuman IgG subclasses. The major observation was that two sera contained, in addition to the anti-desmoplakins I-II, anti-185-kD and anti-230-kD autoantibodies, autoantibodies that stained the desmoglea by indirect immunoelectron microscopy and bound to a 130-kD polypeptide by immunoblotting. One serum was particularly demonstrative: IgG1 bound to the 250- and 220-kD bands corresponding to desmoplakins I and II on immunoblots and to the desmosomal plaques of keratinocytes in immunoelectron microscopic preparations; IgG3 recognized a 185-kD immunoblotting band and hemidesmosomes and desmosomal plaques by immunoelectron microscopy; IgG4 bound to the 130-kD immunoblotting band of pemphigus vulgaris and labeled the desmoglea and the keratinocyte plasma membrane by immunoelectron microscopy. These results demonstrate that the paraneoplastic-pemphigus autoimmune response involves both intracellular and extracellular desmosomal antigens and suggest an overlapping distribution of autoantibody specificities among autoimmune bullous skin diseases.

Aged↗

PubMed1987

Immunoelectron microscopy in subepidermal autoimmune bullous diseases: a prospective study of IgG and C3 bound in vivo in 32 patients.

Thirty-two patients suffering from subepidermal autoimmune bullous disease were studied prospectively by clinical examination and immunoelectron microscopy. Clinically, 1 patient had herpes gestationnis, 14 typical bullous pemphigoid (BP), 3 epidermolysis acquisita (EBA), 3 cicatricial pemphigoid (CP), and 11 patients overlapping clinical diseases. These 11 patients shared clinical features of BP, EBA, or CP and a clinical diagnosis could not be done safely. Immunoelectron microscopy revealed diaminobenzidine deposits in 20 patients on the epidermal side of dermo-epidermal junction in the lamina lucida as in BP. In 5 patients, deposits located mostly under the anchoring fibril zone, in the floor of a sublamina densa dermoepidermal separation for 2 of them, were consistent with a diagnosis of EBA. In 6 patients, deposits were located mostly in the lamina densa, in the floor of a dermoepidermal separation occurring in the lamina lucida for 3 of them. This suggests that some of these 6 patients had neither EBA or BP, but another autoimmune bullous disease again, an uncharacterized component of dermoepidermal junction located in the lamina densa. Finally, a correlation exists between the sites of IgG and/or C3 components on epidermal or dermal side of dermoepidermal junction and the presence or absence of characteristic clinical features such as scar, milia formation, or mucosal involvement.

Adult↗

PubMed1991

Healing of full-thickness cutaneous wounds in the pig. I. Immunohistochemical study of epidermo-dermal junction regeneration.

In order to determine the kinetics of epidermo-dermal junction (EDJ) regeneration during would healing, we studied the regeneration of five EDJ components during reepidermization. Cutaneous wounds (50-mm length, 2-mm width, and 5-mm depth) were produced on the flank area of two pigs and left unsutured. Daily biopsies from day 1 to day 20 were studied by light microscopy on paraffin-embedded sections and by indirect immunofluorescence on cryostat sections using human sera to bullous pemphigoid antigen (BPA) with specificity previously confirmed by indirect immuno-electron microscopy, rabbit antisera to type IV collagen (Coll IV) and to fibronectin, and the monoclonal antibodies (MoAb) 4C 12-8 to laminin and NP-76 to type VII collagen (Coll VII). Histologically, reepidermization started from day 1 and progressed unidirectionally and exclusively from the wound edges. Up to day 9, the distal tips of the neo-epidermal tongues generally extended between the crust and the granulation tissue (GT). They fused on day 10, restoring epidermal continuity. For each EDJ component, the date of appearance (emergence), the spreading under the neo-epidermis tongue (expression), and the morphologic aspect of the labeling were studied. BPA and Coll IV were detected from day 1 to day 20 and found to be expressed all along the neo-EDJ. Fibronectin and laminin were detected from day 1, were present in the proximal and median zones of the neo-EDJ before day 7, up to the distal tip from day 7 to day 9 and were all along the neo-EDJ from day 10 to day 20. Coll VII was only detected from day 3. It was present in the proximal zone on day 3 and day 4, in the proximal and median zones on day 5 and day 6, than all along the neo-EDJ from day 7 to day 20. From day 10, all the labeling characteristics of the five components were found to be similar in the neo-EDJ and in the normal EDJ. With regard to the neo-epidermis progression, we found a synchronism of emergence and expression for BPA and Coll IV, a synchronism of emergence but a delay of expression for fibronectin and laminin and lastly, a delay of emergence and expression for Coll VII. We concluded that BPA and Coll IV could constitute the framework on which the neo-EDJ is progressively built by adjunction of the other components, restitution being obtained just after epidermal continuity is restored.

Animals↗

PubMed1991

Cicatricial pemphigoid antigen differs from bullous pemphigoid antigen by its exclusive extracellular localization: a study by indirect immunoelectronmicroscopy.

Several components of the dermal-epidermal junction (DEJ) bear the name of the autoimmune bullous disease in which they are involved. The epidermolysis bullosa acquisita (EBA) antigen, a component of anchoring fibrils, and the bullous pemphigoid (BP) antigen, a component of hemidesmosomes (HD) with a molecular weight of 220-240 kD, have been well characterized. In contrast, there is little data known about the cicatricial pemphigoid (CP) antigen. No differences between CP and BP have been reported when sera of patients were studied by Western immunoblotting. Findings of a study of sera from 8 patients with CP by indirect immunoelectron microscopy (IEM) on normal human skin are reported. Saponin (0.1% 10 mn) was used as a permeabilizing agent of cytomembranes and saponin-treated skin samples were compared to saponin-untreated skin samples. Four sera from patients with BP, one from a patient with EBA, and three from healthy donors served as controls. The CP sera produced a similar staining of DEJ on both saponin-treated and saponin-untreated skin samples: immune deposits were localized over the lamina densa and the lower part of the lamina lucida clearly separated from the cytoplasmic membrane of keratinocytes, in regularly spaced clumps. The BP sera produced an intense staining of DEJ only on saponin-treated skin samples: immune deposits were observed on the cytoplasmic attachment plaque of the HD; on saponin-untreated skin samples, BP sera produced only a faint staining of the extracellular part of HD. Finally, as expected the EBA serum appeared on the lower part of the lamina densa and anchoring fibrils, and no DAB deposits were observed with the serum of healthy donors. This data indicated that CP antigen is different than BP antigen by its exclusive extracellular localization. It may be a component of anchoring filaments.

Autoantigens↗

PubMed1991

The subclass distribution of IgG autoantibodies in cicatricial pemphigoid and epidermolysis bullosa acquisita.

To study the subclass distribution of autoantibodies and their complement-fixing capacity in cicatricial pemphigoid (CP) and epidermolysis bullosa acquisita (EBA) we studied the sera from 23 patients by both indirect immunofluorescence (IIF) on 4-microns cryostat sections of normal human skin and immunoblotting of epidermal or dermal extracts. Monoclonal antibodies of strict specificity for human IgG subclasses were used. Sera from 20 patients with BP served as controls. In addition, total IgG subclass levels were determined by indirect competitive ELISA in all sera. Complement binding capacity was studied by IIF using antibodies to C3 after incubation of skin section with autoantibodies and source of fresh complement. CP autoantibodies reacting with the 230-240 kD and/or the 180-kD epidermal bands showed an IgG4/IgG1 subclass restriction, with a predominance of IgG4 in 10 cases, of IgG1 in four. In BP sera, IgG4 and IgG1 autoantibodies were detected with a similar frequency (100% and 83%, respectively). In EBA sera, autoantibodies reacting with the 290 kD and 145 kD dermal bands also showed an IgG1/IgG4 restriction. Concordant results were obtained by IIF. However, the IIF method had a lower sensitivity for the detection of IgG4 CP antibodies and IgG1 EBA antibodies than immunoblotting. Finally, when CP antibodies were analyzed for their complement-binding activity, it was found that sera containing IgG4 autoantibodies alone never fixed complement whereas all complement-fixing CP sera had IgG1 autoantibodies, suggesting that only this subclass of antibodies is capable of fixing complement.

Aged↗

PubMed1990

Reversal effects of topical retinoic acid on the skin of kidney transplant recipients under systemic corticotherapy.

The systemic long-term corticosteroid treatment administered to kidney graft recipients (KGR) within the framework of the required immunosuppressive therapy induces an atrophy of the skin, from the sixth month onwards. We studied the effect of topical all-trans retinoic acid (0.05%; Galderma Labs.) applied to the forearms of 27 KGR (14 men, 13 women) over a 6-month period. Twenty-four subjects completed the trial. The following results were obtained in the treated forearm versus the untreated forearm (excipient alone): clinically, an increase in skin thickness; by noninvasive techniques, an increase in skin thickness, skin elasticity, skin conductance, and TEWL, and a reduction in the size of the corneocytes. No change in stratum corneum lipid content was observed. A sex-related difference was noted in the response to treatment under our experimental conditions, the female patients responding better. A punch biopsy (4 mm) was performed on both forearms of four patients after the 6-month period. Histologic and ultrastructural examination revealed epidermal and dermal changes evoking increased cellular metabolism in the retinoic acid-treated forearms.

Administration, Topical↗

PubMed1983

Endogenous peroxidases in normal human dermis: a marker of fibroblast differentiation.

Incubation of unfixed and unfrozen slices of normal human skin allows visualization of a peroxidase activity associated with the perinuclear envelope and with the endoplasmic reticulum of resident dermal macrophages, dermal mastocytes, and also of some dermal fibroblasts. No peroxidase activity can be detected in fibroblasts cultivated in monolayer, while 80% of fibroblasts in an "in vitro" collagen lattice, called a dermal equivalent, express a peroxidase activity in the perinuclear envelope and the endoplasmic reticulum. Hence expression of this peroxidase activity in normal human skin fibroblasts serves as a marker of fibroblast differentiation and seems to depend on an interaction to fibroblast with the elements of a three-dimensional matrix.

Adult↗

PubMed1995

DNA-based prenatal diagnosis of generalized recessive dystrophic epidermolysis bullosa in six pregnancies at risk for recurrence.

Linkage analyses in generalized recessive dystrophic epidermolysis bullosa (RDEB) have implicated the type VII collagen gene (COL7A1), which encodes the major component of anchoring fibrils, and recent identification of COL7A1 mutations has provided direct evidence for COL7A1 defects underlying RDEB. In this study, COL7A1 gene analysis was used to successfully perform first-trimester prenatal diagnosis in six families at risk for recurrence of the disease. In four families, three affected with the most severe variant of RDEB (the Hallopeau-Siemens form, HS-RDEB) and one with generalized nonmutilating RDEB, prenatal diagnosis was established by linkage analysis using polymerase chain reaction-based detection of PvuII and AluI intragenic restriction fragment length polymorphism. In two other HS-RDEB families, prenatal diagnosis was carried out by direct detection of mutations in COL7A1, using denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genomic fragments. Analysis of fetal DNA from chorionic villus biopsy or from amniotic fluid cells showed that the fetus had inherited at least one normal COL7A1 allele in all cases. Therefore, the fetus was predicted to be unaffected in the six pregnancies, and this has been confirmed in the newborn infants. Genotype analysis with COL7A1 polymorphic markers, or direct COL7A1 mutation detection in families at risk for the disease, represent early and rapid diagnostic alternatives to second-trimester evaluation of fetal skin samples, and thus offer a major advance in prenatal diagnosis of this life-threatening form of epidermolysis bullosa.

Base Sequence↗

PubMed1992

The major cicatricial pemphigoid antigen is a 180-kD protein that shows immunologic cross-reactivities with the bullous pemphigoid antigen.

Recent studies have shown that sera from patients with cicatricial pemphigoid (CP) contained autoantibodies against epidermal antigens of molecular weight 230 kD and/or 180 kD by immunoblotting, similar to those recognized by bullous pemphigoid (BP) sera. Previous immunoprecipitation studies have shown that BP sera only precipitated the 230-kD antigen. To characterize the CP antigen(s) we tested 10 CP sera, 10 BP sera, and four controls by both immunoprecipitation of radiolabeled cells and immunoblotting of epidermal extracts. For immunoprecipitation, we used 0.5% NP-40 extracts of both normal human keratinocytes and Pam cells. All CP sera precipitated a 180-kD protein that co-migrated with the BP180 antigen precipitated by some individual BP sera. Two of these CP sera also faintly bound a 230-kD protein of similar molecular weight as the major BP230 antigen. CP and BP sera with an immunoblotting pattern of 180 kD immunoprecipitated a co-migrating 180-kD protein. CP sera reacting by immunoblotting with the 230-kD antigen precipitated the 180-kD and/or the 230-kD antigen. In contrast, BP sera reacting with the 230-kD antigen only precipitated this antigen. In further experiments, labeled 0.5% NP-40 extracts from Pam cells were first preabsorbed with a reference BP serum and then immunoprecipitated with CP sera. Under these conditions, CP sera that immunoprecipitated both 180-kD and 230-kD proteins with the standard procedure no longer precipitated these proteins. Our results suggest that a 180-kD protein is the major CP target-antigen that demonstrated immunologic cross-reactivities with the BP180 and the BP230 antigens.

Antigens↗