1,269 research outputs found
Isolation and characterization of a functionally active protein translocation apparatus from chloroplasts envelopes
Synthesis of Plastoquinone-9, α-Tocopherol and Phylloquinone (Vitamine K1) and its integration in chloroplast carbon metabolism of higher plants
Pilonidalsinus und Analfistel: Indikationen und Methoden der chirurgischen Therapien
Zusammenfassung: Fisteln im Analbereich werden unterteilt in Pilonidalfisteln in der Rima ani und Analfisteln als Verbindung zwischen Anus und perianaler Haut. Bei der Pilonidalfistel erfolgt bei unkompliziertem Befund nach Abheilung akuter Abszesse die minimalinvasive Fistelexzision in Lokalanästhesie. Konservative Therapiekonzepte sowie die radikale Exzision mit offener Wundbehandlung haben sich nicht bewährt. Bei ausgeprägtem, großem Befund erfolgt eine weite Exzision mit plastischer Deckung mittels Limberg-Lappen. Bei der Analfistel muss unterschieden werden zwischen subkutanen und tiefen intersphinktären Fisteln ohne Sphinkterbeteiligung einerseits und hohen intersphinktären, transsphinktären, suprasphinktären und extrasphinktären Fisteln andererseits. Erstere können mit geringer Morbidität und hoher Heilungsrate fistulotomiert werden. Bei der zweiten Gruppe besteht ein erhebliches Inkontinenz- und Rezidivrisiko. Ohne Inkontinenzrisiko, bei allerdings hohem Rezidivrisiko, kann die Fistel mittels "Anal Fistula Plug" verschlossen werden. Bei Versagen dieser Therapie bietet sich eine Fistulektomie mit Verschluss der inneren Fistelöffnung durch einen anorektalen Verschiebelappen a
Experience with a vectorized general circulation weather model on Star-100
A version of an atmospheric general circulation model was vectorized to run on a CDC STAR 100. The numerical model was coded and run in two different vector languages, CDC and LRLTRAN. A factor of 10 speed improvement over an IBM 360/95 was realized. Efficient use of the STAR machine required some redesigning of algorithms and logic. This precludes the application of vectorizing compilers on the original scalar code to achieve the same results. Vector languages permit a more natural and efficient formulation for such numerical codes
A pilot comparative study of fissurectomy/diltiazem and fissurectomy/botulinum toxin in the treatment of chronic anal fissure
Background: Treatment of chronic anal fissure (CAF) by fissurectomy with botulinum toxin A (BTA) injection results in a healing rate of greater than 90%. BTA injection, however, can cause incontinence and perianal sepsis. The decrease in sphincter pressure following topical treatment with 2% diltiazem cream (DTC) is comparable to that following BTA injection but with potentially fewer complications and at less cost. We report the shortterm results of a pilot study comparing fissurectomy with BTA and fissurectomy followed by DTC for the treatment of CAF. Methods: The recorded outcomes of CAF following treatment with the two methods were analysed retrospectively. Patients underwent either fissurectomy followed by injection of 40 U BTA into the internal sphincter (group A) or fissurectomy followed by the perianal application of DTC twice daily for 8 weeks (group B). Symptom resolution and treatment side effects at the initial follow-up were compared. Results: Demographics, fissure characteristics and the number of multiparous women between the two groups were comparable. At a median follow-up of 12 weeks (range 8-20 weeks), the two groups had similar rates of complete symptom resolution (group A, 25/28, 89.3%; group B, 19/23, 82.6%; p=0.7739), with minor side effects. Conclusions: In this small pilot study fissurectomy combined with chemical sphincterotomy resulted in high short-term fissure healing rates. The study also suggested that fissurectomy followed by 8 weeks of topical DTC may be as good as fissurectomy with BTA injection in the treatment of CAF. A prospective study, adequately powered to determine the significance of differences is neede
Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts
The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [γ-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [γ-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110000 × g centrifugation
The protein import apparatus of chloroplasts
Routing of cytosolically synthesized precursor proteins into chloroplasts is a specific process which involves a multitude of soluble and membrane components. In this review we wil1 focus on early events of the translocation pathway of nuclear coded plastidic precursor proteins and compare import routes for polypeptide of the outer chloroplast envelope to that of internal chloroplast compartments. A number of proteins housed in the chloroplast envelopes have been implied to be involved in the translocation process, but so far a certain function has not been assigned to any of these proteins. The only exception could be an envelope localized hsc 70 homologue which could retain the import competence of a precursor protein in transit into the organelle
The postpneumonectomy syndrome: clinical presentation and treatment
Background: Postpneumonectomy syndrome (PPS) is a rare complication after pneumonectomy. It consists of an excessive mediastinal shift resulting in compression and stretching of the tracheobronchial tree and the esophagus. The aim of this study was to give a comprehensive overview of diagnosis, variety of symptoms and evaluation of surgical treatment of PPS. Methods: We retrospectively reviewed the charts of all our patients with PPS since 1994 with respect to symptomatology, treatment and outcome. Our results were compared with case reports and case series in the literature. Results: Six women with a median age of 56.5 years (range 49-65) developed PPS after pneumonectomy for the treatment of lung cancer. Four presented with a right PPS and two with a left PPS, respectively. Symptoms consisted of shortness of breath in all patients and dysphagia as well as heartburn in two patients. Correction of PPS required re-exploration of the pneumonectomy space, reposition of the mediastinum followed by the insertion of single silicone prosthesis in five patients or fixation of the mediastinum with a xenopericardial graft in one patient. We could observe an improvement of the FEV(1)/FVC ratio in all our patients and the clinical improvement of shortness of breath was better than we expected by changes of lung function. Four patients returned to their regular activities with a follow-up of four years. We found 73 cases of PPS in the literature, on the right side in 50 patients (68%) and on the left side in 23 patients (32%). Fifty-nine patients (81%) were treated surgically. Symptoms can be suspicious for cardiogenic origin and vary from heartburn to recurrent syncopes. Conclusion: PPS is rare and not predictable. It can occur after right or left pneumonectomy. Symptoms are manifold and result from a shift, leading to compression and stretching of the two conduits located within the mediastinum, the tracheobronchial tree and the esophagus and consists of shortness of breath, stridor and heartburn. Diagnosis must be made by exclusion. Implantation of prosthesis is the most commonly used and effective treatmen
3D time series analysis of cell shape using Laplacian approaches
Background:
Fundamental cellular processes such as cell movement, division or food uptake critically depend on cells being able to change shape. Fast acquisition of three-dimensional image time series has now become possible, but we lack efficient tools for analysing shape deformations in order to understand the real three-dimensional nature of shape changes.
Results:
We present a framework for 3D+time cell shape analysis. The main contribution is three-fold: First, we develop a fast, automatic random walker method for cell segmentation. Second, a novel topology fixing method is proposed to fix segmented binary volumes without spherical topology. Third, we show that algorithms used for each individual step of the analysis pipeline (cell segmentation, topology fixing, spherical parameterization, and shape representation) are closely related to the Laplacian operator. The framework is applied to the shape analysis of neutrophil cells.
Conclusions:
The method we propose for cell segmentation is faster than the traditional random walker method or the level set method, and performs better on 3D time-series of neutrophil cells, which are comparatively noisy as stacks have to be acquired fast enough to account for cell motion. Our method for topology fixing outperforms the tools provided by SPHARM-MAT and SPHARM-PDM in terms of their successful fixing rates. The different tasks in the presented pipeline for 3D+time shape analysis of cells can be solved using Laplacian approaches, opening the possibility of eventually combining individual steps in order to speed up computations
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