Necrotrophic growth of legionella pneumophila

This study examined whether Legionella pneumophila is able to thrive on heat-killed microbial cells (necrotrophy) present in biofilms or heat-treated water systems. Quantification by means of plate counting, real-time PCR, and flow cytometry demonstrated necrotrophic growth of L. pneumophila in water after 96 h, when at least 100 dead cells are available to one L. pneumophila cell. Compared to the starting concentration of L. pneumophila, the maximum observed necrotrophic growth was 1.89 log units for real-time PCR and 1.49 log units for plate counting. The average growth was 1.57 ± 0.32 log units (n = 5) for real-time PCR and 1.14 ± 0.35 log units (n = 5) for plate counting. Viability staining and flow cytometry showed that the fraction of living cells in the L. pneumophila population rose from the initial 54% to 82% after 96 h. Growth was measured on heat-killed Pseudomonas putida, Escherichia coli, Acanthamoeba castellanii, Saccharomyces boulardii, and a biofilm sample. Gram-positive organisms did not result in significant growth of L. pneumophila, probably due to their robust cell wall structure. Although necrotrophy showed lower growth yields compared to replication within protozoan hosts, these findings indicate that it may be of major importance in the environmental persistence of L. pneumophila. Techniques aimed at the elimination of protozoa or biofilm from water systems will not necessarily result in a subsequent removal of L. pneumophila unless the formation of dead microbial cells is minimized

Evaluation of the safety profile of rotavirus vaccines: a pharmacovigilance analysis on American and European data

Rotaviruses (RVs) are the most common cause of severe diarrheal disease. To date two rotavirus oral vaccines are licensed: Rotarix and Rotateq. Our aim was to contribute to the post-marketing evaluation of these vaccines safety profile. We collected all RV vaccines-related reports of Adverse Events Following Immunization (AEFI) in US Vaccine Adverse Events Reporting System (VAERS) and VigiBase between January 2007 and December 2017. A disproportionality analysis using Reporting Odds Ratio (ROR) was performed. A total of 17,750 reports in VAERS and 6,358 in VigiBase were retrieved. In VAERS, 86.2% of the reports concerned RotaTeq, whereas in VigiBase 67.7% of them involved Rotarix. Across the databases, diarrhea (1,672 events in VAERS, 1,961 in VigiBase) and vomiting (1,746 in VAERS, 1,508 in VigiBase) were the most reported AEFIs. Noteworthy, the RV vaccines-intussusception pair showed a ROR greater than 20 in both databases. Some new potential safety signals emerged such as fontanelle bulging, hypotonic-hyporesponsive episode, livedo reticularis, and opisthotonus. Overall, our data show that most of the reported AEFIs are listed in the Summary of Product Characteristics (SPCs). However, there remains the need to investigate the potential safety signals arose from this analysis, in order to complete the description of the AEFIs

National survey on prescription of cardiovascular drugs among outpatients with coronary artery disease in Switzerland.

Secondary prevention of coronary artery disease markedly reduces cardiovascular mortality and non-fatal endpoints. Outpatient care of subjects with coronary artery disease has been assessed in several European countries, but no current data is available for Switzerland. A random sample of office-based physicians across Switzerland recorded current drug prescription of outpatients with coronary artery disease in the years 2000/2001 by means of a mail questionnaire. We assessed treatment frequencies according to different patient characteristics. 565 patients were included (mean age 68 +/- 11 years, 75% male). There was no evidence for differences in drug utilisation among the regions. Drug prescription rates for antithrombotic agents, beta-blockers, ACE-inhibitors/angiotensin receptor blockers and lipid lowering drugs were 91%, 58%, 50% and 63% respectively. Lower treatment rates were observed among patients >70 years and in those without a history of myocardial infarction or coronary revascularisation. Forty-nine percent of the patients had a blood pressure >140/>90, and 60% had lipid readings above the intervention cut-off according to the Swiss recommendations. Among those without a history of myocardial infarction or coronary revascularisation, the respective figures were 60% and 80%. Compared to former surveys evidence based drug prescription has improved in Switzerland. Despite this, therapeutic goals for cholesterol levels and blood pressure are not being reached in a large proportion of patients. A high risk group for under use of evidence based drugs are patients without a history of myocardial infarction or coronary revascularisation

Co-culture of microalgae, cyanobacteria, and macromycetes for exopolysaccharides production: process preliminary optimization and partial characterization.

In this study, the biomass and exopolysaccharides (EPS) production in co-cultures of microalgae/cyanobacteria and macromycetes was evaluated as a technology for producing new polysaccharides for medical and/or industrial application. Based on biomass and EPS productivity of monocultures, two algae and two fungi were selected and cultured in different co-culture arrangements. The hydrosoluble EPS fractions from mono- and cocultures were characterized by ¹³C NMR spectroscopy and gas chromatography coupled to mass spectrometry and compared. It was found that co-cultures resulted in the production of an EPS different from those produced by monocultures, showing fungal predominance with microalgal/cyanobacterial traces. Co-cultures conditions were screened (temperature, agitation speed, fungal and microalgae inoculation rate, initial pH, illumination rate, and glucose concentration) in order to achieve maximum biomass and EPS production, resulting in an increase of 33 and 61% in exopolysaccharides and biomass productions, respectively (patent pending)

AVALIAÇÃO DA PRODUÇÃO DE METIL-GALACTOPIRANOSÍDEOS NA GLICOSIDAÇÃO DE FISCHER:: INFLUÊNCIA DE CATALISADORES ÁCIDOS HETEROGÊNEOS

A glicosidação de Fischer foi o primeiro método desenvolvido para a síntese de alquil-piranosídeos e é considerado um dos métodos mais econômicos. Porém, o piranosídeo majoritário desta reação, quando se parte da D-galactose, é o metil-α-Galp. Tendo em conta o alto custo do metil-β-Galp, sua importância no mercado de química fina e as vantagens da glicosidação de Fischer, este trabalho teve por objetivo estudar a influência dos catalisadores ácidos heterogêneos na produção de metil-Galps na glicosidação de Fischer, reagindo a galactose com o metanol na presença de diferentes catalisadores ácidos heterogêneos(sílica-ácido-sulfúrico, sílica-ácido-clorossulfónico, alumina sulfúrica e resina catiônica AMBERLITE-IR-120), em diferentes tempos de reação e diferentes temperaturas. O estudo foi realizado em duas etapas. Na etapa I, todos os catalisadores acima citados, foram avaliados nas mesmas condições reacionais. Os principais resultados obtidos nesta etapa, foram otimizados na etapa II, em diferentes condições reacionais, com o uso de ultrassom, quantidades adicionais de água, metanol desidratado e molecular sieives. Os parâmetros que mais contribuiram para os resultados, foram o tempo de reação e temperatura. Os melhores resultados foram obtidos com a sílica-ácido sulfúrico e sílica-ácido clorossulfônico, na temperatura de 64,7ºC. Na temperatura ambiente, o percentual de metil-Galps foi baixíssimo. Ainda na temperatura de 64,7ºC, a maior produção de metil-Galps foi obtida entre 48 h - 72 h, com algumas exceções. Os melhores resultados do estudo, foram obtidos com os catalisadores sílica-ácido sulfúrico em 48 h (56%metil-α-Galp/43%metil-β-Galp) e sílica-ácido clorossulfônico em 5 h (26%metil-α-Galp/33%metil-β-Galp)

Underweight and overweight men have greater exercise-induced dyspnoea than normal weight men.

INTRODUCTION: Persons with high or low body mass index (BMI), involved in clinical or mechanistic trials involving exercise testing, might estimate dyspnoea differently from persons with a normal BMI. AIMS: Our objective was to investigate the relationship between BMI and dyspnoea during exercise in normal subjects with varying BMI. MATERIAL AND METHODS: A total of 37 subjects undertook progressive exercise testing. Subjects were divided into three groups: underweight (UW), normal weight (NW), and overweight (OW). Dyspnoea was estimated using the visual analogue scale (VAS). Spirometry, maximum voluntary ventilation (MVV), and respiratory muscle strength (RMS) were measured. RESULTS AND DISCUSSION: The intercept of the VAS/ventilation relationship was significantly higher in NW subjects compared to UW (P = 0.029) and OW subjects (P = 0.040). Relative to the OW group, FVC (P = 0.020), FEV(1) (P = 0.024), MVV (P = 0.019), and RMS (P = 0.003) were significantly decreased in the UW group. The greater levels of dyspnoea in UW subjects could possibly be due to decreased RMS. Healthy persons should aim to achieve an optimum BMI range to have the lowest exercise-induced dyspnoea

DDIT4/REDD1/RTP801 is a novel negative regulator of schwann cell myelination

Signals that promote myelination must be tightly modulated to adjust myelin thickness to the axonal diameter. In the peripheral nervous system, axonal neuregulin 1 type III promotes myelination by activating erbB2/B3 receptors and the PI3K/AKT/mTOR pathway in Schwann cells. Conversely, PTEN (phosphatase and tensin homolog on chromosome 10) dephosphorylates PtdIns(3,4,5)P3and negatively regulates the AKT pathway and myelination. Recently, the DLG1/SAP97 scaffolding protein was described to interact with PTEN to enhance PIP3dephosphorylation. Here we now report that nerves from mice with conditional inactivation of Dlg1 in Schwann cells display only a transient increase in myelin thickness during development, suggesting that DLG1 is a transient negative regulator of myelination. Instead, we identified DDIT4/RTP801/REDD1 as a sustained negative modulator of myelination. We show that DDIT4 is expressed in Schwann cells and its maximum expression level precedes the peak of AKT activation and of DLG1 activity in peripheral nerves. Moreover, loss of DDIT4 expression both in vitro and in vivo in Ddit4-null mice provokes sustained hypermyelination and enhanced mTORC1 activation, thus suggesting that this molecule is a novel negative regulator of PNS myelination