Zum Feinbau der ForaminifereAllogromia laticollaris

Zusammenfassung 1. Das Cytoplasma im Innern der Schale der monothalamen ForaminifereAllogromia laticollaris ist durch ein zusammenhängendes, die ganze Zelle durchziehendes Lakunensystem aufgelockert und zerklüftet. Dieses System steht über die Schalenöffnung mit dem Außenmedium (Seewasser) in Verbindung und wird zum Cytoplasma hin durch das Plasmalemm abgegrenzt; es ist somit extrazelluläres Gebiet. In extremen Fällen kann bei Zellen mit ausgestreckten Rhizopodien der größte Raum innerhalb der Schale mit Seewasser gefüllt sein. Die Zerklüftung des Cytoplasmas setzt sich im sublichtmikroskopischen Größenbereich weiter fort: Zahlreiche feine, zusammenhängende Cytoplasmastränge, z. T. mit einem Durchmesser von nur ca. 20 mµ, durchziehen diese Seewasser-Lakunen. Dadurch wird eine extreme Oberflächenvergrößerung des Protoplasten innerhalb der Schale erreicht.2. Das Lakunensystem ist daher sicher von Bedeutung für Austauschvorgänge (Atmung, Verdauung), die sich an dieser inneren Oberfläche vollziehen können. Daneben dient es als Platzreservoir für das Rhizopodienmaterial, welches beim Einziehen der Rhizopodien nicht mit dem Cytoplasma im Schalenraum zu einer kompakten Masse verschmolzen, sondern in Form von Strängen gestapelt wird.3. Da das Cytoplasma sowohl im Schalenraum als auch in den Rhizopodien immer in lakunisierter, strangförmiger Form vorliegt, können Ausstrecken und Einziehen der Rhizopodien ohne wesentliche Strukturveränderung des Cytoplasmas erfolgen und deshalb sehr schnell vor sich gehen.4. Innerhalb des Schalenraumes weistA. laticollaris vier unterschiedlich strukturierte Cytoplasmabereiche auf, die bei Zellen mit ausgestreckten Rhizopodien auch durch die quantitativ verschieden starke Ausbildung der Lakunen charakterisiert sind. Der Zellkern wird von einer extreme dünnen Cytoplasmaschicht gesäumt und liegt häufig fast isoliert in einer großen Lichtung des Hohlraumsystems.5. Die durchscheinende, flexible Schale ist aus filamentförmigen Strukturelementen aufgebaut, welche in eine Kittsubstanz eingelagert sind. Sie besteht zumindest teilweise aus sauren Mucopolysacchariden.

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On the fine structure of the foraminiferAllogromia laticollaris. I. Contribution: Cells with extended and withdrawn rhizopodia

The cytoplasm inside the shell of the monothalamous foraminiferAllogromia laticollaris is loosened and disrupted by a continuous vacuolar system (lacunary system), which extends through the entire cell. This system is separated from the cytoplasm by the cell-membrane and is directly connected to the outer medium (sea-water) across the shell-opening; it is therefore extracellular space. In extreme cases, most of the space inside the shell of cells with extended rhizopodia (reticulopodia) is filled with sea-water. The disruption of the cytoplasm is even more visible at a higher magnification: Numerous fine anastamosing cytoplasmic strands, partly with a diameter of only about 20 mµ, extend through these sea-water filled vacuolar spaces (lacunes). In this way an extreme enlargement of the cell-surface inside the shell is attained. Consequently, the lacunary system must be of importance for exchange processes (respiration, digestion) at this inner cell-surface. In addition, this system serves as a reservoir for the rhizopodia-material, not melted into a compact mass together with the cytoplasm inside the shell during rhizopodia withdrawal, but stored in the form of strands. Since the cytoplasm inside the shell, as well as within the reticulopodia, always exists in a vacuolar strand-like form, extension and withdrawal of the rhizopodia can take place without essential changes of the cytoplasmic structure and, therefore, can occur very fast. Within the shellA. laticollaris shows four differently structured cytoplasmic regions. In cells with extended reticulopodia these regions can be characterized by the different degree of extension of the lacunary system. The nucleus is surrounded by an extremely thin cytoplasmic layer and lies, often nearly isolated, within a large lacune of the vacuolar system. The transparent, flexible shell, consisting partly of acid mucopolysaccharides, is composed of filament-like structural elements embedded in a glue-like substance.

     

Lung tissue extracellular matrix-derived hydrogels protect against radiation-induced lung injury by suppressing epithelial–mesenchymal transition

This study aimed to examine whether lung tissue extracellular matrix (ECM) hydrogels have protective effects on radiation-induced lung injury (RILI). The cytocompatibility and histocompatibility were tested for the obtained ECM-derived hydrogel. Sprague–Dawley rats were randomly divided into three groups (n = 18): control group (control); rats receiving irradiation and intratracheal injection of normal saline (IR + NS); and rats receiving irradiation and intratracheal injection of lung ECM-derived hydrogel (IR + ECM). The wet/dry weight ratio was used to evaluate the congestion and edema of the lungs. Histopathological analysis of lung tissues was performed using hemotoxylin and eosin staining and Masson's trichrome staining. Immunohistochemical staining and western blot analyses were carried out to determine the expression of epithelial–mesenchymal transition (EMT)-related proteins in lung tissues (E-cadherin, α-smooth muscle actin [α-SMA], and vimentin). In addition, tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6), hydroxyproline, malondialdehyde (MDA), and superoxide dismutase (SOD) levels were also evaluated. The ECM-derived hydrogels had good cytocompatibility and histocompatibility. ECM-derived hydrogel treatment improved lung histopathology injury and pulmonary edema. Higher expression of E-cadherin and lower expression of vimentin and α-SMA were found in the IR + ECM group compared with those in the IR + NS group. Hydroxyproline levels were reduced by ECM-derived hydrogel treatment compared with those in the IR + NS group. Obvious increases of TNF-α, IL-6, and TGF-β1 were identified following irradiation. Marked reductions in MDA content and increases in SOD were induced by ECM-derived hydrogel treatment in rats after radiation. ECM-derived hydrogels were shown to protect against RILI, potentially by reducing EMT, inflammation, and oxidative damage.     

Mechanical effects of continuous passive motion on the lumbar spine in seating

The aim of this study was to develop a model which describes the mechanical spinal response to small alternating pelvic stimulation induced by an active rotational movement of a normal chair. The rotary continuous passive motion (RCPM) of the seat about a vertical axis of only 0.6 degrees resulted in an increased in spinal length as opposed to the normal daily shrinkage, and back patients experienced pain relief. Passive and active exercies have been broadly applied for treating and healing spinal disorders. A rigid body package (ADAMS Android) was used to translate the stimulation of the ischial tubersoity in caudo-cranial handing-over visualisation. The parameters of the model were set so that the values of the global stiffness and geometry of the intervertebral discs could be changed. In vivo validation of the model was based on force and moment measurements using an internal AO fixator. The predicitons of the model concerning natural frequency (4.5Hz) in vertical direction and the axial torsion response on small pelvic torsion are comparable with experimental data.     

Mapping of citrullinated fibrinogen B-cell epitopes in rheumatoid arthritis by imaging surface plasmon resonance

Introduction  

Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology.     

Association of 25-Hydroxyvitamin D status and genetic variation in the vitamin D metabolic pathway with FEV1 in the Framingham Heart Study

Background

Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.

Methods

We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV₁) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV₁ in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV₁ in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.

Results

We found a positive cross-sectional association between 25(OH)D and FEV₁ in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV₁ in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV₁ (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV₁ in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).

Conclusions

Serum 25(OH)D status was associated with cross-sectional FEV₁, but not longitudinal change in FEV₁. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV₁ and is a promising candidate gene for further studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users.     

Clinical features and predictors for disease natural progression in adults with Pompe disease: a nationwide prospective observational study

Background

Due partly to physicians’ unawareness, many adults with Pompe disease are diagnosed with great delay. Besides, it is not well known which factors influence the rate of disease progression, and thus disease outcome. We delineated the specific clinical features of Pompe disease in adults, and mapped out the distribution and severity of muscle weakness, and the sequence of involvement of the individual muscle groups. Furthermore, we defined the natural disease course and identified prognostic factors for disease progression.

Methods

We conducted a single-center, prospective, observational study. Muscle strength (manual muscle testing, and hand-held dynamometry), muscle function (quick motor function test), and pulmonary function (forced vital capacity in sitting and supine positions) were assessed every 3–6 months and analyzed using repeated-measures ANOVA.

Results

Between October 2004 and August 2009, 94 patients aged between 25 and 75 years were included in the study. Although skeletal muscle weakness was typically distributed in a limb-girdle pattern, many patients had unfamiliar features such as ptosis (23%), bulbar weakness (28%), and scapular winging (33%). During follow-up (average 1.6 years, range 0.5-4.2 years), skeletal muscle strength deteriorated significantly (mean declines of ?1.3% point/year for manual muscle testing and of ?2.6% points/year for hand-held dynamometry; both p<0.001). Longer disease duration (>15 years) and pulmonary involvement (forced vital capacity in sitting position <80%) at study entry predicted faster decline. On average, forced vital capacity in supine position deteriorated by 1.3% points per year (p=0.02). Decline in pulmonary function was consistent across subgroups. Ten percent of patients declined unexpectedly fast.

Conclusions

Recognizing patterns of common and less familiar characteristics in adults with Pompe disease facilitates timely diagnosis. Longer disease duration and reduced pulmonary function stand out as predictors of rapid disease progression, and aid in deciding whether to initiate enzyme replacement therapy, or when.

     

Struktur und chemische asymmetrie von nierenmembranen

Zusammenfassung Die elektronenmikroskopische Untersuchung einiger Membranfraktionen des äußeren Cortex der Säugerniere, welche in Anlehnung an Post und Sen (1967), z.T. mittels Zentrifugation im Rohrzuckerdichtegradienten, gewonnen wurden, hat große Inhomogenität der Präparationen aufgezeigt, sowohl hinsichtlich der Art der Strukturelemente als auch der Größe der Membranfragmente. Die isolierten Membranen bilden meist geschlossene Vesikel. Eine Ausnahme stellt die im Zuckergradienten bei d = 1,1 sich anreichernde Fraktion dar. Sie besteht vorwiegend aus 0,1–0,5 großen Membranvesikeln und offenen Membranfragmenten, bei denen es sich sehr wahrscheinlich um Fragmente der Bürstensäume handelt.Markierungsexperimente mit dem SH-Reagens Hg-Phenyl-Azoferritin haben ergeben, daß die isolierten Membranen ebenso wie diejenigen inkubierter Kryostatschnitte Hg-Ferritin ausschließlich auf der cytoplasmatischen Seite binden. Bezüglich der Besetzungsdichte verhalten sich die Nierenmembranen jedoch inhomogen: Während die Membranen der Mikrovilli und Lysosomen praktisch keinerlei Ferritinanlagerung zeigen, sind die Mitochondrienmembranen dicht markiert. Bei den Membranen des basalen Labyrinths findet man neben einzelnen dicht besetzten Ferritininseln weite Membranabschnitte ohne Hg-Ferritin. Daß das Hg-Ferritin mit den Thiolgruppen der Membranen reagiert, beweist die starke Verringerung der Ferritinbindung nach NEM-Vergiftung der Membranen sowie die unverminderte Anlagerung nach NEM-Behandlung in Gegenwart von ATP, welches die SH-Gruppen in den Membranen vor der Blockierung durch NEM schützt.Werden die Phospholipide mit Phospholipase A und Albumin aus den Membranen entfernt, so ändern sich weder die Morphologie der charakteristischen Strukturelemente der Nierenmembranen noch ihr polares Reaktionsvermögen mit Hg-Ferritin wesentlich.

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Structure and chemical asymmetry of kidney membranesElectron microscopic investigations on different membrane fractions of the outer cortex of mammalian kidney

The electron microscopic investigation of several membrane fractions of the outer cortex of mammalian kidney (pig) isolated according to Post and Sen (1967) and by sucrose gradient centrifugation has revealed great inhomogeneity with regard to the kind of the structural elements as well as to the size of the membrane fragments. The isolated membranes mostly form closed vesicles. As an exception a relatively homogeneous fraction bands at a density of d = 1.1. It consists mainly of membrane vesicles and fragments of a diameter of 0.1–0.5 , which most probably are fragments of the brush borders.Labeling experiments with the SH-reagent Hg-phenyl-azoferritin show that the isolated membranes as well as those of the incubated cryostate sections bind Hg-ferritin exclusively at the cytoplasmic surface. As to the density of the ferritin-labeling: while membranes of the microvilli are practically free of ferritin, the mitochondrial membranes are densely labeled. The membranes of the basal labyrinth exhibit small areas closely packed with ferritin as well as long segments free of ferritin. The thiol-group labeling by Hg-ferritin is proved by the decrease in binding after NEM-poisoning of the membranes as well as by the undiminished attachment after NEM-treatment in the presence of ATP, which protects the SH-groups in the membranes from being blocked by NEM.When the phospholipids are extracted from the membranes with phospholipase A and albumen, neither the morphology of the characteristic structural elements of the kidney membranes nor their polar reaction with Hg-ferritin are changed markedly.

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Fräulein Heidi Behre danken wir für sorgfältige Hilfe bei der Durchführung der Untersuchungen.     

Inhibition of human pancreatic lipase by tetrahydrolipstatin: Further kinetic studies showing its reversibility

Tetrahydrolipstatin (THL, Orlistat) is a potent inhibitor of gastrointestinal lipases. Using the pH-stat technique we report that, in the absence of substrate, THL (at a molar excess of 100) inhibits rapidly (after few minutes of incubation) human pancreatic lipase (HPL). Bile salts over their critical micellar concentration (CMC) were found to accelerate the inhibition process.At variance with the generally accepted model of a covalent and quasi-irreversible acyl-lipase complex, we showed here that the inhibition of HPL could be rapidly and partially reversed in the presence of an emulsion of short- or long-chain triacylglycerols, as indicated by a kinetic reactivation process. The presence of bile salts in the incubation medium, containing THL and HPL, was found to stabilise the covalent complex as reflected by a decrease in the reactivation rate. Paradoxically, the presence of bile salts in the lipase assay enhanced this reactivation process probably by forming mixed micelles between bile salts and THL, which accelerates the deacylation phenomenon.On the basis of this kinetic study, a general model is proposed to describe the inhibition of lipases by THL in the aqueous phase as well as its partial reactivation process at the lipid–water interface.     

Validation data for periprosthetic bone remodelling theories

Periprosthetic adaptive bone remodelling after total hip arthroplasty (THA) has been frequently simulated in computer models, combining bone remodelling theory with finite element analysis. Unfortunately, there still subsist a lack of clinical data, which are necessary for validation of these simulation results. Therefore, the objective of the current project is to collect prospective volumetric bone density data with a clinical computerized tomography study in seven patients after THA. A retrospective study 12 years after implantation in 11 patients was added. A data set of about 100 000 bone voxels for each femur was collected. In all prospective cases, the predominant change is seen during the first year. The average density reduction in the horizontal slices was between 50 and 150 Hounsfield units (HU) (approx. 10%; p<0.001) after 2 years. Loss of density is particularly strong distal of the minor trochanter and decreases from proximal to distal.

For the 12 years retrospective study, the contralateral femur provided the control. Similar trends comparable to the prospective 2-year follow-up CT density values were seen in most cases with density reductions of up to 400 HU (30%). However, in one of these cases there was no difference between the operated and the control density.

As far as we are aware, this is the first collection of fully prospective 3D validation data in vivo for periprosthetic adaptive bone remodelling theories. The data are also unique as they are suitable for direct patient-specific 3D finite element meshing and individual weight-related loading.