140 research outputs found

    Funktionell-morphologische Untersuchungen der Fressmechanismen der Schildkröten Sternotherus odoratus (Latreille, 1802) und Emys orbicularis (Linnaeus, 1758)

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    Innerhalb dieser Arbeit wurden die Nahrungsaufnahmemechanismen zweier subadulter cryptodirer Schildkröten, einerseits die nordamerikanische Gewöhnliche Moschusschildkröte Sternotherus odoratus und andererseits die EuropĂ€ische Sumpfschildkröte Emys orbicularis, untersucht. FĂŒr kinematische Untersuchungen und BewegungsablĂ€ufe wurden Filme unter Laborbedingungen mittels einer High Speed Kamera vom Typus Photron Fastcam 1024 PCI gedreht und mit dem Bewegungsanalyseprogramms SIMI MatchiX ausgewertet. Zur Untersuchung der anatomischen Besonderheiten wurde pro Art je ein subadultes Tier seziert. Von S. odoratus wurden computertomographische Aufnahmen (CT) angefertigt, um den Grad der Ossifizierung der bei der Nahrungsaufnahme beteiligten Skelettelemente zu bestimmen. Bei den untersuchten Arten handelt es sich um rein aquatische Schildkröten, die als aktive JĂ€ger Ă€hnliche AnsprĂŒche an Habitat und Ressourcen stellen. Trotz dieser Gemeinsamkeit konnten Unterschiede in der Anatomie und im Verhalten wĂ€hrend der Nahrungsaufnahme festgestellt werden. Beide Arten besitzen die fĂŒr aquatisch lebende Lebewesen typischen anatomischen Besonderheiten wie einen ausgeprĂ€gten stabilen Hyoidapparat, eine klein ausgebildete Zunge und einen dehnbaren Oropharyngealraum. S. odoratus besitzt im Gegensatz zu E. orbicularis eine hydrodynamischere Kopfform und grĂ¶ĂŸer ausgebildete Adduktormuskeln, die fĂŒr eine deutlich höhere Beißkraft verantwortlich sind. Die kinematischen Untersuchungen zeigen die typischen, fĂŒr aquatische Nahrungsaufnahme spezialisierten koordinierten BewegungsablĂ€ufe, die sich jedoch in der Anzahl der Transporte und den Geschwindigkeiten der einzelnen SchĂ€delelemente unterscheiden. Beide Arten können als Generalisten bezeichnet werden, wohingegen die aggressivere S. odoratus durch die gesteigerte Beißkraft noch opportunistischer lebt, da zusĂ€tzlich hĂ€rtere Nahrung als potenzielle Beute angesehen werden kann. E. orbicularis hingegen zeigt sich der dargebotenen Nahrung gegenĂŒber vorsichtig im Verhalten und benötigt zur ÜberprĂŒfung der Nahrung auf Verwertbarkeit mehrere Transportzyklen.The feeding mechanism of two subadult cryptodiran turtles, the North American Common Musk Turtle Sternotherus odoratus and the European Pond Turtle Emys orbicularis, were studied. Under laboratory conditions the High speed camera Photron Fastcam 1024 PCI and the motion analysis program SIMI MatchiX was used for analysing kinematic variables and movements while feeding. The anatomy of all skeletal as well as muscular elements was investigated by dissection; photos of each dissection stage of one subadult individual per species were taken. Moreover we used computer tomography (CT) for S. odoratus to investigate the level of ossification of all skeletal parts of head and hyoid. Both investigated species are purely aquatic feeding turtles which demand the same habitat and resources. In purely aquatic feeders the hyoid apparatus is solid and large, whereas the tongue is small. The oropharyngeal cavity is very extendable to assimilate the water during ingestion. Despite of these similarities we found some distinctions in anatomy and behaviour. The design of the head of S. odoratus is more hydrodynamic and the adductor is stronger developed to increase the bite force. Kinematic researches showed coordinated movements of the skeletal elements which differ in number and velocity within the two species. Both species are generalists and active hunters but S. odoratus is more aggressive and opportunistic than E. orbicularis. The latter is more careful and needs more transport cycles to proof inherent nutrition

    Fatal pitfalls in newborn screening for mitochondrial trifunctional protein (MTP)/long-chain 3-Hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency

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    Background: Mitochondrial trifunctional protein (MTP) and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency are long-chain fatty acid oxidation disorders with particularly high morbidity and mortality. Outcome can be favorable if diagnosed in time, prompting the implementation in newborn screening programs. Sporadic cases missed by the initial screening sample have been reported. However, little is known on pitfalls during confirmatory testing resulting in fatal misconception of the diagnosis. Results: We report a series of three patients with MTP and LCHAD deficiency, in whom diagnosis was missed by newborn screening, resulting in life-threatening metabolic decompensations within the first half year of life. Two of the patients showed elevated concentrations of primary markers C16-OH and C18:1-OH but were missed by confirmatory testing performed by the maternity clinic. A metabolic center was not consulted. Confirmatory testing consisted of analyses of acylcarnitines in blood and organic acids in urine, the finding of normal excretion of organic acids led to rejection and underestimation of the diagnosis, respectively. The third patient, a preterm infant, was not identified in the initial screening sample due to only moderate elevations of C16-OH and C18:1-OH and normal secondary markers and analyte ratios. Conclusion: Our observations highlight limitations of newborn screening for MTP/LCHAD deficiency. They confirm that analyses of acylcarnitines in blood and organic acids in urine alone are not suitable for confirmatory testing and molecular or functional analysis is crucial in diagnosing MTP/LCHAD deficiency. Mild elevations of primary biomarkers in premature infants need to trigger confirmatory testing. Our report underscores the essential role of specialized centers in confirming or ruling out diagnoses in suspicious screening results

    Obtaining Patient-Reported Outcomes Electronically With “OncoFunction” in Head and Neck Cancer Patients During Aftercare

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    The disease and treatment of patients with head and neck cancer can lead to multiple late and long-term sequelae. Especially pain, psychosocial problems, and voice issues can have a high impact on patients’ health-related quality of life. The aim was to show the feasibility of implementing an electronic Patient-Reported Outcome Measure (PROM) in patients with head and neck cancer (HNC). Driven by our department’s intention to assess Patient-Reported Outcomes (PRO) based on the International Classification of Functioning during tumor aftercare, the program “OncoFunction” has been implemented and continuously refined in everyday practice. The new version of “OncoFunction” was evaluated by 20 head and neck surgeons and radiation oncologists in an interview. From 7/2013 until 7/2017, 846 patients completed the PROM during 2,833 of 3,610 total visits (78.5%). The latest software version implemented newly developed add-ins and increased the already high approval ratings in the evaluation as the number of errors and the time required decreased (6 vs. 0 errors, 1.35 vs. 0.95 min; p<0.01). Notably, patients had different requests using PRO in homecare use. An additional examination shows that only 59% of HNC patients use the world wide web. Using OncoFunction for online-recording and interpretation of PROM improved data acquisition in daily HNC patients’ follow-up. An accessory timeline grants access to former consultations and their visualization supported and simplified structured examinations. This provides an easy-to-use representation of the patient’s functional outcome supporting comprehensive aftercare, considering all aspects of the patient’s life

    Fluvial network organization imprints on microbial co-occurrence networks

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    Recent studies highlight linkages among the architecture of ecological networks, their persistence facing environmental disturbance, and the related patterns of biodiversity. A hitherto unresolved question is whether the structure of the landscape inhabited by organisms leaves an imprint on their ecological networks. We analyzed, based on pyrosequencing profiling of the biofilm communities in 114 streams, how features inherent to fluvial networks affect the co-occurrence networks that the microorganisms form in these biofilms. Our findings suggest that hydrology and metacommunity dynamics, both changing predictably across fluvial networks, affect the fragmentation of the microbial co-occurrence networks throughout the fluvial network. The loss of taxa from co-occurrence networks demonstrates that the removal of gatekeepers disproportionately contributed to network fragmentation, which has potential implications for the functions biofilms fulfill in stream ecosystems. Our findings are critical because of increased anthropogenic pressures deteriorating stream ecosystem integrity and biodiversity

    Evaluation of polygenic risk scores for breast and ovarian cancer risk prediction in BRCA1 and BRCA2 mutation carriers

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    Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates. Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS. Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2 x 10(53)). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2 x 10(-20)). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS. Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management

    Alu elements as regulators of gene expression

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    Alu elements are the most abundant repetitive elements in the human genome; they emerged 65 million years ago from a 5â€Č to 3â€Č fusion of the 7SL RNA gene and amplified throughout the human genome by retrotransposition to reach the present number of more than one million copies. Over the last years, several lines of evidence demonstrated that these elements modulate gene expression at the post-transcriptional level in at least three independent manners. They have been shown to be involved in alternative splicing, RNA editing and translation regulation. These findings highlight how the genome adapted to these repetitive elements by assigning them important functions in regulation of gene expression. Alu elements should therefore be considered as a large reservoir of potential regulatory functions that have been actively participating in primate evolution

    Programmed cell death ligand 1 (PD-L1, CD274) in cholangiocarcinoma – correlation with clinicopathological data and comparison of antibodies

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    Background: Cholangiocarcinoma (CCA) may arise in the intra- or extrahepatic biliary tract and is associated with a poor prognosis. Despite recent advances, to date there is still no established targeted therapeutic approach available. Non-surgical therapeutic agents are urgently needed, as most patients are non-eligible to surgical resection. Anti-PD-L1 therapy prevents cancer cells from evading the immune system and has emerged as a new treatment option in several cancer entities. Recently, PD-L1 expression has been analyzed in comparably small CCA patient cohorts. However, a systematic validation of different PD-L1 antibodies has not been performed in CCA so far. Methods: We stained a tissue microarray consisting of 170 patients, including 72 intrahepatic cholangiocarcinomas (iCCAs), 57 perihilar cholangiocarcinomas (pCCAs) and 41 distal cholangiocarcinomas (dCCAs) by immunohistochemistry and evaluated PD-L1 positivity in tumor and stromal cells. We analyzed three different PD-L1 antibodies (clones 28–8, SP142, and SP263) that are frequently used and recommended for predictive diagnostic testing in other cancer types. Results: For PD-L1 antibody clone SP263, 5% of iCCAs, 4% of pCCAs and 3% of dCCAs exhibited PD-L1 expression on tumor cells, thereby showing the highest frequencies of PD-L1 positivity. Accordingly, highest PD-L1 positivity rates of stromal cells with 31% in iCCA, 40% in pCCA and 61% in dCCA were detected for clone SP263. Agreement of PD-L1 positivity in tumor cells was moderate for clone 28–8 and SP263 (Îș = 0.44) and poor between 28-8 and SP142 (Îș = 0.13), as well as  SP142 and SP263 (Îș = 0.11), respectively. Statistical analyses of PD-L1 expression (clone SP263) on tumor cells with clinicopathological data revealed a positive correlation with shortened overall survival in CCA patients. Conclusions: Selection of appropriate PD-L1 antibodies and careful evaluation of immunohistochemical staining patterns have a significant impact on PD-L1 testing in CCA. Clinical trials are necessary to investigate the putative beneficial effects of PD-L1 targeted immunotherapy in CCA patients

    Voronoi Tessellation Captures Very Early Clustering of Single Primary Cells as Induced by Interactions in Nascent Biofilms

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    Biofilms dominate microbial life in numerous aquatic ecosystems, and in engineered and medical systems, as well. The formation of biofilms is initiated by single primary cells colonizing surfaces from the bulk liquid. The next steps from primary cells towards the first cell clusters as the initial step of biofilm formation remain relatively poorly studied. Clonal growth and random migration of primary cells are traditionally considered as the dominant processes leading to organized microcolonies in laboratory grown monocultures. Using Voronoi tessellation, we show that the spatial distribution of primary cells colonizing initially sterile surfaces from natural streamwater community deviates from uniform randomness already during the very early colonisation. The deviation from uniform randomness increased with colonisation — despite the absence of cell reproduction — and was even more pronounced when the flow of water above biofilms was multidirectional and shear stress elevated. We propose a simple mechanistic model that captures interactions, such as cell-to-cell signalling or chemical surface conditioning, to simulate the observed distribution patterns. Model predictions match empirical observations reasonably well, highlighting the role of biotic interactions even already during very early biofilm formation despite few and distant cells. The transition from single primary cells to clustering accelerated by biotic interactions rather than by reproduction may be particularly advantageous in harsh environments — the rule rather than the exception outside the laboratory
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