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Brominated Skeletal Components of the Marine Demosponges, Aplysina cavernicola and Ianthella basta: Analytical and Biochemical InvestigationsKunze, Kurt, Niemann, Hendrik, Ueberlein, Susanne, Schulze, Renate, Ehrlich, Hermann, Brunner, Eike, Proksch, Peter, Pée, Karl-Heinz van 28 November 2013 (has links) (PDF)
Demosponges possess a skeleton made of a composite material with various organic constituents and/or siliceous spicules. Chitin is an integral part of the skeleton of different sponges of the order Verongida. Moreover, sponges of the order Verongida, such as Aplysina cavernicola or Ianthella basta, are well-known for the biosynthesis of brominated tyrosine derivates, characteristic bioactive natural products. It has been unknown so far whether these compounds are exclusively present in the cellular matrix or whether they may also be incorporated into the chitin-based skeletons. In the present study, we therefore examined the skeletons of A. cavernicola and I. basta with respect to the presence of bromotyrosine metabolites. The chitin-based-skeletons isolated from these sponges indeed contain significant amounts of brominated compounds, which are not easily extractable from the skeletons by common solvents, such as MeOH, as shown by HPLC analyses in combination with NMR and IR spectroscopic measurements. Quantitative potentiometric analyses confirm that the skeleton-associated bromine mainly withstands the MeOH-based extraction. This observation suggests that the respective, but yet unidentified, brominated compounds are strongly bound to the sponge skeletons, possibly by covalent bonding. Moreover, gene fragments of halogenases suggested to be responsible for the incorporation of bromine into organic molecules could be amplified from DNA isolated from sponge samples enriched for sponge-associated bacteria.
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'Candidatus Megaira polyxenophila' gen. nov., sp. nov.: Considerations on Evolutionary History, Host Range and Shift of Early Divergent RickettsiaeSchrallhammer, Martina, Ferrantini, Filippo, Vannini, Claudia, Galati, Stefano, Schweikert, Michael, Görtz, Hans-Dieter, Verni, Franco, Petroni, Giulio 28 November 2013 (has links) (PDF)
“Neglected Rickettsiaceae” (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria.
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Cortisol Awakening Response Is Linked to Disease Course and Progression in Multiple SclerosisKern, Simone, Krause, Ivonne, Horntrich, Antje, Thomas, Katja, Aderhold, Julia, Ziemssen, Tjalf 22 January 2014 (has links) (PDF)
Objectives: Dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis has frequently been reported in multiple sclerosis (MS). So far, HPA axis function in MS has predominantly been studied under pharmacological stimulation which is associated with a series of methodological caveats. Knowledge of circadian cortisol patterns and cortisol awakening response (CAR) is still limited.
Methods: A total of 77 MS patients (55 relapsing-remitting MS (RRMS)/22 secondary-progressive MS (SPMS)) as well as 34 healthy control (HC) subjects were enrolled. Diurnal cortisol release was assessed by repeated salivary cortisol sampling. Neurological disability was rated by the Kurtzke’s Expanded Disability Status Scale (EDSS). Depressive symptoms and perceived stress were assessed by self-report measures.
Results: RRMS but not SPMS patients differed in circadian cortisol release from HC subjects. Differences in cortisol release were restricted to CAR. Treated and treatment naïve RRMS patients did not differ in CAR. In a RRMS follow-up cohort (nine months follow-up), RRMS patients with EDSS progression (≥0.5) expressed a significantly greater CAR compared to HC subjects. RRMS patients with a stable EDSS did not differ from HC subjects. Neither depressive symptoms nor perceived stress ratings were associated with CAR in RRMS patients. In a step-wise regression analysis, EDSS at baseline and CAR were predictive of EDSS at follow-up (R2 = 67%) for RRMS patients.
Conclusions: Circadian cortisol release, in particular CAR, shows a course specific pattern with most pronounced release in RRMS. There is also some evidence for greater CAR in RRMS patients with EDSS progression. As a consequence, CAR might be of predictive value in terms of neurological disability in RRMS patients. The possible role of neuroendocrine-immune interactions in MS pathogenesis is further discussed.
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Olfactory Training in Patients with Parkinson's DiseaseHähner, Antje, Tosch, Clara, Wolz, Martin, Klingelhöfer, Lisa, Fauser, Mareike, Storch, Alexander, Reichmann, Heinz, Hummel, Thomas 22 January 2014 (has links) (PDF)
Objective: Decrease of olfactory function in Parkinson's disease (PD) is a well-investigated fact. Studies indicate that pharmacological treatment of PD fails to restore olfactory function in PD patients. The aim of this investigation was whether patients with PD would benefit from “training” with odors in terms of an improvement of their general olfactory function. It has been hypothesized that olfactory training should produce both an improved sensitivity towards the odors used in the training process and an overall increase of olfactory function.
Methods: We recruited 70 subjects with PD and olfactory loss into this single-center, prospective, controlled non-blinded study. Thirty-five patients were assigned to the olfactory training group and 35 subjects to the control group (no training). Olfactory training was performed over a period of 12 weeks while patients exposed themselves twice daily to four odors (phenyl ethyl alcohol: rose, eucalyptol: eucalyptus, citronellal: lemon, and eugenol: cloves). Olfactory testing was performed before and after training using the “Sniffin' Sticks” (thresholds for phenyl ethyl alcohol, tests for odor discrimination, and odor identification) in addition to threshold tests for the odors used in the training process.
Results: Compared to baseline, trained PD patients experienced a significant increase in their olfactory function, which was observed for the Sniffin' Sticks test score and for thresholds for the odors used in the training process. Olfactory function was unchanged in PD patients who did not perform olfactory training.
Conclusion: The present results indicate that olfactory training may increase olfactory sensitivity in PD patients.
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A Genome-Wide Association Study Suggests Novel Loci Associated with a Schizophrenia-Related Brain-Based PhenotypeHass, Johanna, Walton, Esther, Kirsten, Holger, Liu, Jingyu, Priebe, Lutz, Wolf, Christiane, Karbalai, Nazanin, Gollub, Randy, White, Tonya, Rößner, Veit, Müller, Kathrin U., Paus, Tomas, Smolka, Michael N., Schumann, Gunter, Scholz, Markus, Cichon, Sven, Calhoun, Vince, Ehrlich, Stefan 22 January 2014 (has links) (PDF)
Patients with schizophrenia and their siblings typically show subtle changes of brain structures, such as a reduction of hippocampal volume. Hippocampal volume is heritable, may explain a variety of cognitive symptoms of schizophrenia and is thus considered an intermediate phenotype for this mental illness. The aim of our analyses was to identify single-nucleotide polymorphisms (SNP) related to hippocampal volume without making prior assumptions about possible candidate genes. In this study, we combined genetics, imaging and neuropsychological data obtained from the Mind Clinical Imaging Consortium study of schizophrenia (n = 328). A total of 743,591 SNPs were tested for association with hippocampal volume in a genome-wide association study. Gene expression profiles of human hippocampal tissue were investigated for gene regions of significantly associated SNPs. None of the genetic markers reached genome-wide significance. However, six highly correlated SNPs (rs4808611, rs35686037, rs12982178, rs1042178, rs10406920, rs8170) on chromosome 19p13.11, located within or in close proximity to the genes NR2F6, USHBP1, and BABAM1, as well as four SNPs in three other genomic regions (chromosome 1, 2 and 10) had p-values between 6.75×10−6 and 8.3×10−7. Using existing data of a very recently published GWAS of hippocampal volume and additional data of a multicentre study in a large cohort of adolescents of European ancestry, we found supporting evidence for our results. Furthermore, allelic differences in rs4808611 and rs8170 were highly associated with differential mRNA expression in the cis-acting region. Associations with memory functioning indicate a possible functional importance of the identified risk variants. Our findings provide new insights into the genetic architecture of a brain structure closely linked to schizophrenia. In silico replication, mRNA expression and cognitive data provide additional support for the relevance of our findings. Identification of causal variants and their functional effects may unveil yet unknown players in the neurodevelopment and the pathogenesis of neuropsychiatric disorders.
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An N-terminal domain helical motif of Prototype Foamy Virus Gag with dual functions essential for particle egress and viral infectivityReh, Juliane, Stange, Annett, Götz, Anne, Rönitz, Marlene, Große, Arend, Lindemann, Dirk 22 January 2014 (has links) (PDF)
Background: Foamy viruses (FVs) have developed a unique budding strategy within the retrovirus family. FV release requires co-expression and a highly specific interaction between capsid (Gag) and glycoprotein (Env), which cannot be complemented by heterologous Env proteins. The interaction domain in FV Env has been mapped in greater detail and resides mainly in the N-terminal tip of the cytoplasmic domain of the Env leader peptide subunit. In contrast, the corresponding domain within Gag is less well defined. Previous investigations suggest that it is located within the N-terminal part of the protein.
Results: Here we characterized additional Gag interaction determinants of the prototype FV (PFV) isolate using a combination of particle release, GST pull-down and single cycle infectivity analysis assays. Our results demonstrate that a minimal PFV Gag protein comprising the N-terminal 129 aa was released into the supernatant, whereas proteins lacking this domain failed to do so. Fine mapping of domains within the N-terminus of PFV Gag revealed that the N-terminal 10 aa of PFV Gag were dispensable for viral replication. In contrast, larger deletions or structurally deleterious point mutations in C-terminally adjacent sequences predicted to harbor a helical region abolished particle egress and Gag – Env protein interaction. Pull-down assays, using proteins of mammalian and prokaryotic origin, support the previous hypothesis of a direct interaction of both PFV proteins without requirement for cellular cofactors and suggest a potential direct contact of Env through this N-terminal Gag domain. Furthermore, analysis of point mutants within this domain in context of PFV vector particles indicates additional particle release-independent functions for this structure in viral replication by directly affecting virion infectivity.
Conclusions: Thus, our results demonstrate not only a critical function of an N-terminal PFV Gag motif for the essential capsid - glycoprotein interaction required for virus budding but also point out additional functions that affect virion infectivity.
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Anti-Vascular endothelial growth factor therapy impairs endothelial function of retinal microcirculation in colon cancer patients – an observational studyReimann, Manja, Folprecht, Gunnar, Haase, Rocco, Trautmann, Karolin, Ehninger, Gerhard, Reichmann, Heinz, Ziemssen, Focke, Ziemssen, Tjalf 22 January 2014 (has links) (PDF)
Background: To assess acute effects of bevacizumab (anti-VEGF therapy) on cerebral microvessels and systemic cardiovascular regulation.
Design and subjects: 20 consecutive patients with colorectal cancer (median age: 60.4 years, range 45.5-73.9 years) received bevacizumab intravenously (5 mg/kg) uncoupled of chemotherapy. Prior to and within the first 24 hours after bevacizumab infusion, patients were investigated for retinal endothelial function. A series of a triple 24-hour ambulatory blood pressure measurement was conducted. Retinal endothelial function was determined as flicker light-induced vasodilation. The integrity of baroreflex arc and autonomic cardiovascular control was examined by stimulatory manoeuvres.
Results: Bevacizumab therapy significantly reduced the vasodilatory capacity of retinal arterioles in response to flicker light. A slight decrease in diastolic pressure and heart rate was observed after bevacizumab infusion but this was unrelated to changes in retinal function. The pressure response upon nitroglycerin was largely preserved after bevacizumab infusion. The proportion of patients with abnormal nocturnal blood pressure regulation increased under anti-angiogenic therapy. Autonomic blood pressure control was not affected by bevacizumab treatment.
Conclusions: Bevacizumab acutely impairs microvascular function independent of blood pressure changes. Imaging of the retinal microcirculation seems a valuable tool for monitoring pharmacodynamic effects of bevacizumab.
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Do current screening recommendations allow for early detection of lithium-induced hyperparathyroidism in patients with bipolar disorder?Berger, Michael, Riedel, Michael, Tomova, Nora, Obermeier, Michael, Seemüller, Florian, Dittmann, Sandra, Möller, Hans-Jürgen, Severus, Emanuel 22 January 2014 (has links) (PDF)
Background: Current screening recommendations for early detection of lithium-associated hyperparathyroidism propose an exclusive measurement of serum albumin-adjusted calcium (Aac) concentration as a single first step. However, longitudinal data in patients with recurrent affective disorders suggest that increases in serum intact parathyroid hormone (iPTH) levels in lithium-treated patients may not necessarily be accompanied by a parallel increase in the concentration of Aac. If true, patients with an isolated increase in iPTH concentration above the reference range might be missed following current screening recommendations. Therefore, this study set out to examine key parameters of calcium metabolism, including iPTH and 25-hydroxycholecalciferol concentrations in patients with bipolar disorder that was or was not managed with lithium.
Methods: Sixty patients with bipolar disorder according to DSM-IV were enrolled, 30 of whom had received long-term lithium treatment (lithium group), whereas the other 30 patients were on psychopharmacological treatment not including lithium (non-lithium group) at the time of the study. Owing to exclusion criteria (e.g., lithium < 6 months, laboratory results indicative of secondary hyperparathyroidism), 23 bipolar patients composed the final lithium group, whereas 28 patients remained in the non-lithium group for statistical analyses.
Results: Patients in the lithium group showed a significantly higher concentration of iPTH compared to the non-lithium group (p < 0.05). Similarly, Aac concentrations were significantly increased in the lithium group compared to the non-lithium group (p < 0.05). However, in a multivariate linear regression model, group affiliation only predicted iPTH concentration (p < 0.05). In line with this, none of the four patients in the lithium group with an iPTH concentration above the reference range had an Aac concentration above the reference range.
Discussion: This study suggests that the biochemical characteristics between primary hyperparathyroidism and lithium-induced hyperparathyroidism differ substantially with regard to regulation of calcium homeostasis. As such, current screening practice does not reliably detect iPTH concentrations above the reference range. Therefore, further research is needed to elucidate the consequences of an isolated iPTH concentration above the reference range in order to develop the most appropriate screening tools for hyperparathyroidism in lithium-treated patients with bipolar disorder.
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一位台灣博士生於英語教學學術社群的參與經驗之敘事探究 / A Narrative Inquiry into Experience of A Taiwanese Ph.D. Student Participating in the TESOL Academic Community蔣宗益, Chiang, Tsung Yi Unknown Date (has links)
本研究為長期性的敘事研究,運用了Wenger (1998)的「實踐社群」社會學習理論(communities of practice),以及Norton(1995)的投資理論 (investment),研究目的是為了探索一位台灣的英語教學研究所博士生的學術成長經驗及其所衍生的意義,特別是針對他奮勉進行學術研究投稿、完成博士學位、並進而開啟他未來的學術生涯等等的過程。本研究主要追蹤了研究參與者在其博士生涯的三個形成階段中,他的學術投稿經驗的心路歷程,一路到研究參與者最後在全球的英語教學領域之學術社群中取得更完全的參與度階段。為了能夠對於研究參與者其經驗有深入的了解,本研究採用了「敘事研究法」,收集了研究參與者的學習經驗自傳、敘說訪談的錄音及其逐字稿、研究者的現場筆記及研究筆記、以及其他由研究參與者所提供的文件等資料,以便能分析參與者的言談資料、且對資料進行敘事性的分析、並進而產出情節故事作為研究結果。研究結果發現,研究參與者持續努力來達成其所認定的學術投稿要求,確實增長了他在學術素養的成長,並足以成為學術社群當中的一員。在其過程當中,研究參與者對於實踐其學術投稿的過程當中相關資源的運用方式,與在Wenger ‘s (1998) 「實踐社群」社會學習理論的非正式學習的特色是相互呼應的。研究參與者在學術社群當中所獲得的參與度,也表現出了其所累積的文化資產。最重要的是,從研究參與者的經驗透露出,就其受到英語教學社群的社會文化的影響之下來看,研究參與者埋首致力於學術投稿活動不僅僅是為了當下於英語教學社群的參與,也為了即將到來的終生志業進行Norton (1995)理論當中的個人投資的傾向。這樣的情況顯示出,要學習成為一個英語教學研究領域的學者,的確是涉及了諸多層面的複雜構面及諸多意義上的磋商。而就整個過程來說,也是與研究參與者,他身為初階的年輕學人,身處於台灣的社會情境當中,為了能夠符合全球各地諸多種類專業社群的規範,他以放遠全球的思維來,來實踐在地的行動,成長中的信念是有所共鳴的。最後,本研究將針對台灣高等教育環境中的英語教學研究領域之博士班課程提出建議並討論,以促進年青學人們在學術領域的發展。 / Drawing on Wenger’s (1998) social learning theory as well as Norton’s (1995) notion of investment, this longitudinal qualitative study aims to investigate and derive meanings from the academic experience of one former Taiwanese TESOL doctoral student as he struggled to write for scholarly publications, survived the Ph.D. program, and initiated his academic career. The study mainly traces the twists and turns of his publishing experience in three stages of his forming years till the participant finally has acquired a fuller membership in the global TESOL academic community. To capture and derive an in-depth understanding of the experiences, a narrative inquiry approach was adopted, collecting the young scholar’s written autobiography, recorded narrative interviews and transcripts, the researcher’s research notes and other related documents that the participant provided, so as to thematically analyze the narrative data and then exert the narrative analysis to configure the happenings and events into seven emplotted narratives as the research results. The findings indicate that the participant’s continual endeavor to meet the perceived and assumed requirements for publishing indeed rendered him the academic literacy development necessary to become a member of the academic community. In the process, the participant’s ways of utilizing resources situated in the practice of publishing echo the features of informal learning in Wenger’s (1998) social learning theory. The membership in the academic community gained by the participant also indicates the accumulated cultural capital. Most importantly, the participant’s experience as a doctoral student, being socially and culturally medicated by the TESOL academic community, reveals a tendency to engage in academic tasks for scholarly purposes not only for the current participation in the TESOL academic community but also for personal investment (Norton, 1995) for the coming life-long career. This suggests learning to become a TESOL scholar indeed involves multiple layers of complexity and challenges, and the whole process is also a resonant to his growing faith as a novice young scholar, situated in the social context of Taiwan, to act locally and think globally, in order to conform to norms of various discourse communities around the world. Suggestions for TESOL doctoral programs in Taiwanese higher education to help and support young scholars’ academic development are discussed.
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An Extremely Rare, Remote Intracerebral Metastasis of Oral Cavity Cancer: A Case ReportLeimert, Mario, Juratli, Tareq A., Lindner, Claudia, Geiger, Kathrin D., Gerber, Johannes, Schackert, Gabriele, Kirsch, Matthias 06 February 2014 (has links) (PDF)
Distant brain metastases from oral squamous cell carcinomas (OSCC) are extremely rare. Here we describe a case of a 53-year-old man with a primary OSCC who referred to the neurosurgical department because of epileptic seizures. MR imaging revealed an enhancing lesion in the right parietal lobe. A craniotomy with tumor removing was performed. Histopathological examination verified an invasive, minimally differentiated metastasis of the primary OSCC. The patient refused whole brain radiation therapy and died from pulmonary metastatic disease 10 months after the neurosurgical intervention without any cerebral recurrence. To the authors’ knowledge, only two similar cases have been previously reported.
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