Selective isolation and taxonomical characterization of bacteria from the rhizosphere of Leontopodium nivale subsp. alpinum

Die zunehmende Resistenzentwicklung von Krankheitserregern gegenüber Antibiotika ist Anlass für eine intensivierte Suche nach natürlichen Substanzen, die zu Antibiotika weiterentwickelt werden können. Bodenbakterien, vor allem Actinomyceten, produzieren zwei Drittel aller klinisch gebräuchlichen Antibiotika natürlichen Ursprungs. Actinomyceten sind nach wie vor reiche Quellen noch unentdeckter Substanzen. Diese Bakterien wurden bisher hauptsächlich aus Bodenproben isoliert, die Rhizosphäre traditioneller Arzneipflanzen ist hingegen weitgehend unerforscht. Die traditionelle Arzneipflanze Alpen-Edelweiß aus heimischen Vorkommen auf der Rax sowie die Bakterien aus der Rhizosphäre dieser Pflanze standen im Mittelpunkt dieses Projekts. Zur selektiven Isolation von Bakterien wurden Bodenproben aus der Rhizosphäre des Alpen-Edelweißes verwendet. Sechs selektive Medien, entwickelt für die Isolation seltener Aktinomyceten, wurden mit Vorbehandlungsmethoden zur Reduktion häufig vorkommender Bakterien kombiniert. Zur weiteren Selektion wurden drei antibiotische Behandlungsvarianten eingesetzt. Die Bakterienkolonien wurden nach morphologischen Kriterien der Aktinomyceten sowie nach Beobachtung antimikrobieller Aktivität auf Agarplatten ausgewählt. Isolierte Bakterien wurden kultiviert, deren genomische DNA gewonnen, 16S-rDNA vervielfältigt und sequenziert. Die taxonomische Charakterisierung erfolgte durch Vergleich mit bekannten Typstämmen im Rahmen phylogenetischer Stammbäume. Die Mehrheit der sequenzierten Isolate gehört dem Stamm der Aktinobakterien an. Zu den isolierten seltenen Aktinomyceten gehören die Gattungen Actinokineospora, Asanoa, Kitasatospora, Microbacterium, Micrococcus, Mycobacterium und Nocardia. Die vorherrschenden Gattungen waren Streptomyces und Micromonospora. Insgesamt wurden in diesem Projekt 15 verschiedene Bakteriengattungen isoliert. Die beobachtete Bioaktivität in Kontakt mit anderen Bakterien war auf einige Paenibacillus-Spezies und wenige Bacillus-Spezies zurückzuführen. Diese Arbeit stellt eine Grundlage für ein zukünftiges Projekt dar, welches die potentielle Produktion neuer antimikrobiell aktiver Substanzen untersucht.Ever increasing resistance of pathogens to antimicrobial agents, prompts humankind to urgently search for novel natural compounds that may be developed into antibiotics. Soil-dwelling bacteria, especially actinomycetes, are known as producers of more than 66 % of all antibiotics of natural origin, which are currently applied clinically (Barka et al., 2016). Actinomycetes are still worthwhile sources of yet unknown compounds. These bacteria have been mostly isolated from soil samples, but rhizospheres of traditional medicinal plants still remain under-investigated. In this study we focus on the ancient medicinal plant Leontopodium nivale subsp. alpinum from the native alpine range and its rhizosphere bacteria. Soil samples from the rhizosphere were used to selectively isolate bacteria. Six media selective for rare actinomycetes were combined with soil pre-treatments to eradicate abundant other bacteria, and three antibiotic treatments were applied as additional selective forces. Bacterial colonies were selected based on actinomycetes morphology characteristics and observed bioactivity on agar plates. Isolated bacteria were cultivated and the genomic DNA was extracted. 16S-rDNA was amplified, sequenced and used to construct phylogenetic trees to compare isolates to known type strains. The majority of the sequenced isolates belongs to the phylum Actinobacteria. Rare actinomycetes included the genera Actinokineospora, Asanoa, Kitasatospora, Microbacterium, Micrococcus, Mycobacterium and Nocardia. Dominating isolates belonged to the genera Streptomyces and Micromonospora. In total, bacteria of 15 different genera were isolated in this project. Furthermore, bioactivity in contact with other bacteria was observed and assigned to several Paenibacillus species and a few Bacillus species. This work provides a foundation for a future project, aimed at testing these bacteria for the potential production of novel antimicrobial compounds

Bevacizumab plus chemotherapy as first-line treatment for patients with metastatic colorectal cancer: Results from a large German community-based observational cohort study

<div><p></p><p><b>Background.</b> After approval of bevacizumab in Germany in 2005 for the treatment of unresectable advanced or refractory colorectal cancer (CRC), this observational cohort study was initiated to assess the efficacy and safety of bevacizumab with various chemotherapy regimen in patients with metastatic CRC (mCRC).</p><p><b>Material and methods.</b> To facilitate enrolment of a typical mCRC population, eligibility criteria were minimised. Choice of chemotherapy regimen was at the physicians’ discretion, but influenced by current registration status. Predefined endpoints were treatment characteristics, response rate, progression-free survival (PFS), overall survival (OS) and adverse events assessed as potentially related to bevacizumab treatment. Patients were followed for up to four years.</p><p><b>Results.</b> In total 1777 eligible patients were enrolled at 261 sites from January 2005 to June 2008. Median age: 64 years (range 19–100); male 62%; ECOG performance status 0–1/≥ 2 89%/11%. Chemotherapy choice was fluoropyrimidine (FU) 12%, FU/oxaliplatin 18%, FU/irinotecan 64%, no chemotherapy concurrent to bevacizumab 2% and other 4%. Best investigator-assessed response rate was 60% (complete response 10%, partial response 51%). Median PFS was 10.2 months and median OS was 24.8 months.</p><p><b>Conclusions.</b> The efficacy and safety profile of bevacizumab in this population of mCRC patients with different chemotherapy regimens is consistent with that observed in other patient registries/non-randomised trials and also corresponds well with data from similar treatment arms of phase III trials.</p></div

Quality of life in the GLARIUS trial randomizing bevacizumab/irinotecan versus temozolomide in newly diagnosed, MGMT-nonmethylated glioblastoma

Background: The GLARIUS trial, which investigated the efficacy of bevacizumab (BEV)/irinotecan (IRI) compared with standard temozolomide in the first-line therapy of O-6-methylguanine-DNA methyltransferase (MGMT)nonmethylated glioblastoma, showed that progression-free survival was significantly prolonged by BEV/IRI, while overall survival was similar in both arms. The present report focuses on quality of life (QoL) and Karnofsky performance score (KPS) during the whole course of the disease. Methods: Patients (n = 170) received standard radiotherapy and were randomized (2: 1) for BEV/IRI or standard temozolomide. At least every 3 months KPS was determined and QoL was measured using the European Organisation for Research and Treatment of Cancer 30-item Core Quality of Life and 20-item Brain Neoplasm questionnaires. A generalized estimating equation (GEE) model evaluated differences in the course of QoL and KPS over time. Also, the time to first deterioration and the time to postprogression deterioration were analyzed separately. Results: In all dimensions of QoL and KPS, GEE analyses and time to first deterioration analyses did not detect significant differences between the treatment arms. At progression, 82% of patients receiving second-line therapy in the standard arm received BEV second-line therapy. For the dimensions of motor dysfunction and headaches, time to postprogression deterioration was prolonged in the standard arm receiving crossover second-line BEV in the vast majority of patients at the time of evaluation. Conclusions: GLARIUS did not find indications for a BEV-induced detrimental effect on QoL in first-line therapy of MGMT-nonmethylated GBM patients. Moreover, GLARIUS provided some indirect corroborative data supporting the notion that BEV may have beneficial effects upon QoL in relapsed GBM

Bevacizumab Plus Irinotecan Versus Temozolomide in Newly Diagnosed O-6-Methylguanine-DNA Methyltransferase Nonmethylated Glioblastoma: The Randomized GLARIUS Trial

Purpose In patients with newly diagnosed glioblastoma that harbors a nonmethylated O-6-methylguanine-DNA methyltransferase promotor, standard temozolomide (TMZ) has, at best, limited efficacy. The GLARIUS trial thus explored bevacizumab plus irinotecan (BEV+IRI) as an alternative to TMZ. Patients and Methods In this phase II, unblinded trial 182 patients in 22 centers were randomly assigned 2: 1 to BEV (10mg/kg every 2 weeks) during radiotherapy (RT) followed by maintenance BEV (10mg/kg every 2 weeks) plus IRI(125 mg/m(2) every 2 weeks) or to daily TMZ (75 mg/m(2)) during RT followed by six courses of TMZ (150-200 mg/m(2)/d for 5 days every 4 weeks). The primary end point was the progression-free survival rate after 6 months (PFS-6). Results In the modified intention-to-treat (ITT) population, PFS-6 was increased from 42.6% with TMZ(95% CI, 29.4% to 55.8%) to 79.3% with BEV+IRI (95% CI, 71.9% to 86.7%; P < .001). PFS was prolonged from a median of 5.99 months (95% CI, 2.7 to 7.3 months) to 9.7 months (95% CI, 8.7 to 10.8 months; P < .001). At progression, crossover BEV therapy was given to 81.8% of all patients who received any sort of second-line therapy in the TMZ arm. Overall survival (OS) was not different in the two arms: the median OS was 16.6 months (95% CI, 15.4 to 18.4 months) with BEV+IRI and was 17.5 months (95% CI, 15.1 to 20.5 months) with TMZ. The time course of quality of life (QOL) in six selected domains of the European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire (QLQ)-C30 and QLQ-BN20 (which included cognitive functioning), of the Karnofsky performance score, and of the Mini Mental State Examination score was not different between the treatment arms. Conclusion BEV+IRI resulted in a superior PFS-6 rate and median PFS compared with TMZ. However, BEV+IRI did not improve OS, potentially because of the high crossover rate. BEV+IRI did not alter QOL compared with TMZ. (C) 2016 by American Society of Clinical Oncolog

Maternal choline supplementation improves spatial learning and adult hippocampal neurogenesis in the Ts65Dn mouse model of Down syndrome

In addition to intellectual disability, individuals with Down syndrome (DS) exhibit dementia by the third or fourth decade of life, due to the early onset of neuropathological changes typical of Alzheimer’s disease (AD). Deficient ontogenetic neurogenesis contributes to the brain hypoplasia and hypocellularity evident in fetuses and children with DS. A murine model of DS and AD (the Ts65Dn mouse) exhibits key features of these disorders, notably deficient ontogenetic neurogenesis, degeneration of basal forebrain cholinergic neurons (BFCNs), and cognitive deficits. Adult hippocampal (HP) neurogenesis is also deficient in Ts65Dn mice and may contribute to the observed cognitive dysfunction. Herein, we demonstrate that supplementing the maternal diet with additional choline (approximately 4.5 times the amount in normal rodent chow) dramatically improved the performance of the adult trisomic offspring in a radial arm water maze task. Ts65Dn offspring of choline-supplemented dams performed significantly better than unsupplemented Ts65Dn mice. Furthermore, adult hippocampal neurogenesis was partially normalized in the maternal choline supplemented (MCS) trisomic offspring relative to their unsupplemented counterparts. A significant correlation was observed between adult hippocampal neurogenesis and performance in the water maze, suggesting that the increased neurogenesis seen in the supplemented trisomic mice contributed functionally to their improved spatial cognition. These findings suggest that supplementing the maternal diet with additional choline has significant translational potential for DS