256 research outputs found
Secondary bacterial infections of buruli ulcer lesions before and after chemotherapy with streptomycin and rifampicin
Buruli ulcer (BU), caused by Mycobacterium ulcerans is a chronic necrotizing skin disease. It usually starts with a subcutaneous nodule or plaque containing large clusters of extracellular acid-fast bacilli. Surrounding tissue is destroyed by the cytotoxic macrolide toxin mycolactone produced by microcolonies of M. ulcerans. Skin covering the destroyed subcutaneous fat and soft tissue may eventually break down leading to the formation of large ulcers that progress, if untreated, over months and years. Here we have analyzed the bacterial flora of BU lesions of three different groups of patients before, during and after daily treatment with streptomycin and rifampicin for eight weeks (SR8) and determined drug resistance of the bacteria isolated from the lesions. Before SR8 treatment, more than 60% of the examined BU lesions were infected with other bacteria, with Staphylococcus aureus and Pseudomonas aeruginosa being the most prominent ones. During treatment, 65% of all lesions were still infected, mainly with P. aeruginosa. After completion of SR8 treatment, still more than 75% of lesions clinically suspected to be infected were microbiologically confirmed as infected, mainly with P. aeruginosa or Proteus miriabilis. Drug susceptibility tests revealed especially for S. aureus a high frequency of resistance to the first line drugs used in Ghana. Our results show that secondary infection of BU lesions is common. This could lead to delayed healing and should therefore be further investigated
Minería de datos para el descubrimiento de patrones en enfermedades respiratorias en Bogotá, Colombia
Trabajo de InvestigaciónEl presente proyecto se basa en la aplicación de minería de datos mediante el algoritmo de clustering K- means que permita la generación de un modelo descriptivo con el análisis de los datos y con el objetivo de identificar posibles comportamientos en enfermedades respiratorias en la ciudad de Bogotá.
El conjunto de clústeres generados por la herramienta RapidMiner es la
recopilación de datos de un periodo de cinco años de 2012 a 2016, en donde se contemplan el número de casos asociados a 184 diagnósticos de enfermedades respiratorias y la edad de los pacientes corresponde de 0 a 5 años.Trabajo de Investigación1. GENERALIDADES
2. OBJETIVOS
3. JUSTIFICACIÓN
4. DELIMITACIÓN
5. MARCO REFERENCIAL
6. METODOLOGÍA
7. FUENTES DE EXTRACCIÓN Y SUS VARIABLES
8. DISEÑO
9. SELECCIÓN DE ALGORITMOS DE CLUSTERING
10. RECONOCER PATRONES A PARTIR DE LA INFORMACIÓN RECOPILADA
11. CONCLUSIONES
12. TRABAJOS FUTUROS 13. REFERENCIAS BIBLIOGRÁFICAS
14. ANEXOSPregradoIngeniero de Sistema
The impact of language barriers on trust formation in multinational teams
This study systematically investigates how language barriers influence trust formation in multinational teams (MNTs). Based on 90 interviews with team members, team leaders, and senior managers in 15 MNTs in three German automotive corporations, we show how MNT members’ cognitive and emotional reactions to language barriers influence their perceived trustworthiness and intention to trust, which in turn affect trust formation.
We contribute to diversity research by distinguishing the exclusively negative language effects from the more ambivalent effects of other diversity dimensions. Our findings also illustrate how surface-level language diversity may create perceptions of deep-level diversity. Furthermore, our study advances MNT research by revealing the specific influences of language barriers on team trust, an important mediator between team inputs and performance outcomes. It thereby encourages the examination of other team processes through a language lens.
Finally, our study suggests that multilingual settings necessitate a reexamination and modification of the seminal trust theories by Mayer, Davis and Schoorman (1995) and McAllister (1995). In terms of practical implications, we outline how MNT leaders can manage their subordinates’ problematic reactions to language barriers and how MNT members can enhance their perceived trustworthiness in multilingual settings
A randomised, double-blind, placebo-controlled trial of repeated nebulisation of non-viral cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy in patients with cystic fibrosis
BACKGROUND: Cystic fibrosis (CF) is a chronic, life-limiting disease caused by mutations in the CF
transmembrane conductance regulator (CFTR) gene leading to abnormal airway surface ion transport,
chronic lung infections, inflammation and eventual respiratory failure. With the exception of the
small-molecule potentiator, ivacaftor (Kalydeco®, Vertex Pharmaceuticals, Boston, MA, USA), which is
suitable for a small proportion of patients, there are no licensed therapies targeting the basic defect.
The UK Cystic Fibrosis Gene Therapy Consortium has taken a cationic lipid-mediated CFTR gene therapy
formulation through preclinical and clinical development.
OBJECTIVE: To determine clinical efficacy of the formulation delivered to the airways over a period of
1 year in patients with CF.
DESIGN: This was a randomised, double-blind, placebo-controlled Phase IIb trial of the CFTR gene–liposome
complex pGM169/GL67A. Randomisation was performed via InForm™ version 4.6 (Phase Forward
Incorporated, Oracle, CA, USA) and was 1 : 1, except for patients in the mechanistic subgroups (2 : 1).
Allocation was blinded by masking nebuliser chambers.
SETTINGS: Data were collected in the clinical and scientific sites and entered onto a trial-specific InForm,
version 4.6 database.
PARTICIPANTS: Patients with CF aged ≥ 12 years with forced expiratory volume in the first second (FEV1)
between 50% and 90% predicted and any combination of CFTR mutations. The per-protocol group
(≥ 9 doses) consisted of 54 patients receiving placebo (62 randomised) and 62 patients receiving gene
therapy (78 randomised).
INTERVENTIONS: Subjects received 5 ml of nebulised pGM169/G67A (active) or 0.9% saline (placebo) at
28 (±5)-day intervals over 1 year.
MAIN OUTCOME MEASURES: The primary end point was the relative change in percentage predicted FEV1
over the 12-month period. A number of secondary clinical outcomes were assessed alongside safety
measures: other spirometric values; lung clearance index (LCI) assessed by multibreath washout; structural
disease on computed tomography (CT) scan; the Cystic Fibrosis Questionnaire – Revised (CFQ-R), a
validated quality-of-life questionnaire; exercise capacity and monitoring; systemic and sputum inflammatory
markers; and adverse events (AEs). A mechanistic study was performed in a subgroup in whom transgene
deoxyribonucleic acid (DNA) and messenger ribonucleic acid (mRNA) was measured alongside nasal and
lower airway potential difference.
RESULTS: There was a significant (p = 0.046) treatment effect (TE) of 3.7% [95% confidence interval (CI)
0.1% to 7.3%] in the primary end point at 12 months and in secondary end points, including forced vital
capacity (FVC) (p = 0.031) and CT gas trapping (p = 0.048). Other outcomes, although not reaching
statistical significance, favoured active treatment. Effects were noted by 1 month and were irrespective
of sex, age or CFTR mutation class. Subjects with a more severe baseline FEV1 had a FEV1 TE of 6.4%
(95% CI 0.8% to 12.1%) and greater changes in many other secondary outcomes. However, the more
mildly affected group also demonstrated benefits, particularly in small airway disease markers such as LCI.
The active group showed a significantly (p = 0.032) greater bronchial chloride secretory response. No
difference in treatment-attributable AEs was seen between the placebo and active groups.
CONCLUSIONS: Monthly application of the pGM169/GL67A gene therapy formulation was associated with
an improvement in lung function, other clinically relevant parameters and bronchial CFTR function,
compared with placebo.
LIMITATIONS: Although encouraging, the improvement in FEV1 was modest and was not accompanied by
detectable improvement in patients’ quality of life.
FUTURE WORK: Future work will focus on attempts to increase efficacy by increasing dose or frequency,
the coadministration of a CFTR potentiator, or the use of modified viral vectors capable of
repeated administration.
TRIAL REGISTRATION: ClinicalTrials.gov NCT01621867
Monsters, Laws of Nature, and Teleology in Late Scholastic Textbooks
In the period of emergence of early modern science, ‘monsters’ or individuals with physical congenital anomalies were considered as rare events which required special explanations entailing assumptions about the laws of nature. This concern with monsters was shared by representatives of the new science and Late Scholastic authors of university textbooks. This paper will reconstruct the main theses of the treatment of monsters in Late Scholastic textbooks, by focusing on the question as to how their accounts conceived nature’s regularity and teleology. It shows that they developed a naturalistic teratology in which, in contrast to the naturalistic explanations usually offered by the new science, finality was at central stage. This general point does not impede our noticing that some authors were closer to the views emerging in the Scientific Revolution insofar as they conceived nature as relatively autonomous from God and gave a relevant place to efficient secondary causation. In this connection, this paper suggests that the concept of the laws of nature developed by the new science –as exception-less regularities—transferred to nature’s regularity the ‘strong’ character that Late Scholasticism attributed to finality and that the decline of the Late Scholastic view of finality played as an important concomitant factor permitting the transformation of the concept of laws of nature
Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case-controlled study
<p>Abstract</p> <p>Background</p> <p>The long term adverse effects of Severe Acute Respiratory Syndrome (SARS), a viral disease, are poorly understood.</p> <p>Methods</p> <p>Sleep physiology, somatic and mood symptoms of 22 Toronto subjects, 21 of whom were healthcare workers, (19 females, 3 males, mean age 46.29 yrs.+/- 11.02) who remained unable to return to their former occupation (mean 19.8 months, range: 13 to 36 months following SARS) were compared to 7 healthy female subjects. Because of their clinical similarities to patients with fibromyalgia syndrome (FMS) these post-SARS subjects were similarly compared to 21 drug free female patients, (mean age 42.4 +/- 11.8 yrs.) who fulfilled criteria for fibromyalgia.</p> <p>Results</p> <p>Chronic post-SARS is characterized by persistent fatigue, diffuse myalgia, weakness, depression, and nonrestorative sleep with associated REM-related apneas/hypopneas, an elevated sleep EEG cyclical alternating pattern, and alpha EEG sleep anomaly. Post- SARS patients had symptoms of pre and post-sleep fatigue and post sleep sleepiness that were similar to the symptoms of patients with FMS, and similar to symptoms of patients with chronic fatigue syndrome. Both post-SARS and FMS groups had sleep instability as indicated by the high sleep EEG cyclical alternating pattern rate. The post-SARS group had a lower rating of the alpha EEG sleep anomaly as compared to the FMS patients. The post-SARS group also reported less pre-sleep and post-sleep musculoskeletal pain symptoms.</p> <p>Conclusions</p> <p>The clinical and sleep features of chronic post-SARS form a syndrome of chronic fatigue, pain, weakness, depression and sleep disturbance, which overlaps with the clinical and sleep features of FMS and chronic fatigue syndrome.</p
Acinetobacter baumannii Infection Inhibits Airway Eosinophilia and Lung Pathology in a Mouse Model of Allergic Asthma
Allergic asthma is a dysregulation of the immune system which leads to the development of Th2 responses to innocuous antigens (allergens). Some infections and microbial components can re-direct the immune response toward the Th1 response, or induce regulatory T cells to suppress the Th2 response, thereby inhibiting the development of allergic asthma. Since Acinetobacter baumannii infection can modulate lung cellular and cytokine responses, we studied the effect of A. baumannii in modulating airway eosinophilia in a mouse model of allergic asthma. Ovalbumin (OVA)-sensitized mice were treated with live A. baumannii or phosphate buffered saline (PBS), then intranasally challenged with OVA. Compared to PBS, A. baumannii treatment significantly reduced pulmonary Th2 cytokine and chemokine responses to OVA challenge. More importantly, the airway inflammation in A. baumannii-treated mice was strongly suppressed, as seen by the significant reduction of the proportion and the total number of eosinophils in the bronchoalveolar lavage fluid. In addition, A. baumannii-treated mice diminished lung mucus overproduction and pathology. However, A. baumannii treatment did not significantly alter systemic immune responses to OVA. Serum OVA-specific IgE, IgG1 and IgG2a levels were comparable between A. baumannii- and PBS-treated mice, and tracheobronchial lymph node cells from both treatment groups produced similar levels of Th1 and Th2 cytokines in response to in vitro OVA stimulation. Moreover, it appears that TLR-4 and IFN-γ were not directly involved in the A. baumannii-induced suppression of airway eosinophilia. Our results suggest that A. baumannii inhibits allergic airway inflammation by direct suppression of local pulmonary Th2 cytokine responses to the allergen
Punicic Acid a Conjugated Linolenic Acid Inhibits TNFα-Induced Neutrophil Hyperactivation and Protects from Experimental Colon Inflammation in Rats
BACKGROUND:Neutrophils play a major role in inflammation by releasing large amounts of ROS produced by NADPH-oxidase and myeloperoxidase (MPO). The proinflammatory cytokine TNFalpha primes ROS production through phosphorylation of the NADPH-oxidase subunit p47phox on Ser345. Conventional anti-inflammatory therapies remain partially successful and may have side effects. Therefore, regulation of neutrophil activation by natural dietary components represents an alternative therapeutic strategy in inflammatory diseases such as inflammatory bowel diseases. The aim of this study was to assess the effect of punicic acid, a conjugated linolenic fatty acid from pomegranate seed oil on TNFalpha-induced neutrophil hyperactivation in vitro and on colon inflammation in vivo. METHODOLOGY AND PRINCIPAL FINDINGS:We analyzed the effect of punicic acid on TNFalpha-induced neutrophil upregulation of ROS production in vitro and on TNBS-induced rat colon inflammation. Results show that punicic acid inhibited TNFalpha-induced priming of ROS production in vitro while preserving formyl-methionyl-leucyl-phenylalanine (fMLP)-induced response. This effect was mediated by the inhibition of Ser345-p47phox phosphorylation and upstream kinase p38MAPK. Punicic acid also inhibited fMLP- and TNFalpha+fMLP-induced MPO extracellular release from neutrophils. In vivo experiments showed that punicic acid and pomegranate seed oil intake decreased neutrophil-activation and ROS/MPO-mediated tissue damage as measured by F2-isoprostane release and protected rats from TNBS-induced colon inflammation. CONCLUSIONS/SIGNIFICANCE:These data show that punicic acid exerts a potent anti-inflammatory effect through inhibition of TNFalpha-induced priming of NADPH oxidase by targeting the p38MAPKinase/Ser345-p47phox-axis and MPO release. This natural dietary compound may provide a novel alternative therapeutic strategy in inflammatory diseases such as inflammatory bowel diseases
Understanding Communication Signals during Mycobacterial Latency through Predicted Genome-Wide Protein Interactions and Boolean Modeling
About 90% of the people infected with Mycobacterium tuberculosis carry latent bacteria that are believed to get activated upon immune suppression. One of the fundamental challenges in the control of tuberculosis is therefore to understand molecular mechanisms involved in the onset of latency and/or reactivation. We have attempted to address this problem at the systems level by a combination of predicted functional protein∶protein interactions, integration of functional interactions with large scale gene expression studies, predicted transcription regulatory network and finally simulations with a Boolean model of the network. Initially a prediction for genome-wide protein functional linkages was obtained based on genome-context methods using a Support Vector Machine. This set of protein functional linkages along with gene expression data of the available models of latency was employed to identify proteins involved in mediating switch signals during dormancy. We show that genes that are up and down regulated during dormancy are not only coordinately regulated under dormancy-like conditions but also under a variety of other experimental conditions. Their synchronized regulation indicates that they form a tightly regulated gene cluster and might form a latency-regulon. Conservation of these genes across bacterial species suggests a unique evolutionary history that might be associated with M. tuberculosis dormancy. Finally, simulations with a Boolean model based on the regulatory network with logical relationships derived from gene expression data reveals a bistable switch suggesting alternating latent and actively growing states. Our analysis based on the interaction network therefore reveals a potential model of M. tuberculosis latency
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