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1.
Microbiol Spectr ; 11(3): e0525422, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37097170

ABSTRACT

The human gut microbiome plays a vital role in health and disease. In particular, the first days of life provide a unique window of opportunity for development and establishment of microbial community. Currently, stool samples are known to be the most widely used sampling approach for studying the gut microbiome. However, complicated sample acquisition at certain time points, challenges in transportation, and patient discomfort underline the need for development of alternative sampling approaches. One of the alternatives is rectal swabs, shown to be a reliable proxy for gut microbiome analysis when obtained from adults. Here, we compare the usability of rectal swabs and meconium paired samples collected from infants on the first days of life. Our results indicate that the two sampling approaches display significantly distinct patterns in microbial composition and alpha and beta diversity as well as detection of resistance genes. Moreover, the dissimilarity between the two collection methods was greater than the interindividual variation. Therefore, we conclude that rectal swabs are not a reliable proxy compared to stool samples for gut microbiome analysis when collected on the first days of a newborn's life. IMPORTANCE Currently, there are numerous suggestions on how to ease the notoriously complex and error-prone methodological setups to study the gut microbiota of newborns during the first days of life. Especially, meconium samples are regularly failing to yield meaningful data output and therefore have been suggested to be replaced by rectal swabs as done in adults as well. We find this development toward a simplified method to be producing dramatically erroneous results, skewing data interpretation away from the real aspects to be considered for neonatal health during the first days of life. We have put together our knowledge on this critical aspect with careful consideration and identified the failure of rectal swabs to be a replacement for sampling of meconium in term-born newborns.


Subject(s)
Meconium , Microbiota , Infant , Adult , Humans , Infant, Newborn , Feces , Anti-Bacterial Agents , RNA, Ribosomal, 16S/genetics , Microbiota/genetics
2.
Heliyon ; 8(12): e12177, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36510570

ABSTRACT

Right from the start of the COVID pandemic in January 2020, the entire tourism sector was put under immense pressure because of its assumed role in SARS-CoV-2 transmission and infection dynamics. Based on reports of single superspreading events in the early days of the pandemic, the hotel industry appeared in a bad light that impaired a strategic risk-assessment of existing transmission risks between tourists and employees. We prospectively analysed samples of 679 employees of 21 hotels and restaurants from July 2020 to December 2020, a time during which more than 1.5 million tourists visited the Lübeck/Ostholstein Baltic Sea vacation area in Northern Germany. Employees were tested up to three times for an acute SARS-CoV-2 infection (PCR from nasopharyngeal swabs) and the presence of SARS-CoV-2 specific antibodies, and were asked to complete a short questionnaire. Despite the massive increase in tourist influx, no significant increase in SARS-CoV-2 cases was observed amongst employees of the tourism sector from July to September 2020. In a cluster-outbreak analysis of 104 study participants of one single hotel in the Lübeck/Ostholstein region in October 2020 being employed in the low-wage sector "housekeeping" could be determined as major risk factor for becoming infected. In conclusion, in a low incidence setting, touristic activities are safe under COVID-related hygiene measures for both the local population and employees of the tourism sector. Whereas, the field of work is a potential risk factor for increased infection dynamics.

3.
BMC Infect Dis ; 22(1): 587, 2022 Jul 02.
Article in English | MEDLINE | ID: mdl-35780088

ABSTRACT

BACKGROUND: Healthcare workers (HCW) are at increased risk of infection with SARS-CoV-2. Vulnerable patient populations in particular must be protected, and clinics should not become transmission hotspots to avoid delaying medical treatments independent of COVID. Because asymptomatic transmission has been described, routine screening of asymptomatic HCW would potentially be able to interrupt chains of infection through early detection. METHODS: A systematic search was conducted in the Cochrane COVID-19 Study Register, Web of Science and WHO COVID-19 Global literature on coronavirus with regard to non-incident related testing of healthcare workers using polymerase chain reaction on May 4th 2021. Studies since January 2020 were included. An assessment of risk of bias and representativeness was performed. RESULTS: The search identified 39 studies with heterogeneous designs. Data collection of the included studies took place from January to August 2020. The studies were conducted worldwide and the sample size of the included HCW ranged from 70 to 9449 participants. In total, 1000 of 51,700 (1.9%) asymptomatic HCW were tested positive for SARS-CoV-2 using PCR testing. The proportion of positive test results ranged between 0 and 14.3%. No study reported on HCW-screening related reductions in infected person-days. DISCUSSION AND CONCLUSIONS: The heterogeneous proportions might be explained by different regional incidences, lock-downs, and pre-analytical pitfalls that reduce the sensitivity of the nasopharyngeal swab. The very high prevalence in some studies indicates that screening HCW for SARS-CoV-2 may be important particularly in geographical regions and pandemic periods with a high-incidence. With low numbers and an increasing rate of vaccinated HCW, a strict cost-benefit consideration must be made, especially in times of low incidences. Since we found no studies that reported on HCW-screening related reductions in infected person-days, re-evaluation should be done when these are available.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/epidemiology , Communicable Disease Control , Delivery of Health Care , Health Personnel , Hospitals , Humans
4.
Pneumologie ; 75(9): 665-729, 2021 Sep.
Article in German | MEDLINE | ID: mdl-34198346

ABSTRACT

The present guideline provides a new and updated concept of the management of adult patients with community-acquired pneumonia. It replaces the previous guideline dating from 2016.The guideline was worked out and agreed on following the standards of methodology of a S3-guideline. This includes a systematic literature search and grading, a structured discussion of recommendations supported by the literature as well as the declaration and assessment of potential conflicts of interests.The guideline has a focus on specific clinical circumstances, an update on severity assessment, and includes recommendations for an individualized selection of antimicrobial treatment.The recommendations aim at the same time at a structured assessment of risk for adverse outcome as well as an early determination of treatment goals in order to reduce mortality in patients with curative treatment goal and to provide palliation for patients with treatment restrictions.


Subject(s)
Communicable Diseases , Emergency Medicine , Pneumonia , Pulmonary Medicine , Adult , Aged , Austria , Critical Care , Germany , Humans , Physicians, Family
5.
Infection ; 49(3): 533-537, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33774804

ABSTRACT

To determine the most relevant pathogens for CAP in Germany, patients with radiologically confirmed pulmonary infiltrates and at least one clinical sign of lung infection were prospectively recruited within the CAPNETZ cohort from 2004 until 2016. In 990 out of 4.672 patients (21%) receiving complete diagnostics the most prominent change of pathogens was a decrease of S. pneumoniae (58% in 2004 to 37.5% in 2016; p ≤ 0.001, ρ = - 0.148) and an increase of H. influenzae (12.2% to 20.8%; p = 0.001, ρ = 0.104).


Subject(s)
Community-Acquired Infections , Pneumonia, Bacterial , Bacteria , Community-Acquired Infections/epidemiology , Haemophilus influenzae , Humans , Pneumonia, Bacterial/diagnosis , Pneumonia, Bacterial/epidemiology , Streptococcus pneumoniae
6.
Int J Tuberc Lung Dis ; 23(8): 913-918, 2019 08 01.
Article in English | MEDLINE | ID: mdl-31533881

ABSTRACT

OBJECTIVE: To perform a nationwide inventory of diagnostic mycobacteriology services in Germany.METHOD: A survey was conducted among participants of the national mycobacteriology external quality assurance scheme asking for smear microscopy techniques, molecular assays, culture systems and drug susceptibility testing (DST) capacities for Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM), and numbers of processed/culture-positive samples, and DSTs performed in 2016.RESULTS: We found that 170/238 laboratories (71.4%) provided data. Numbers of samples processed for culture varied between 35 and 40 000 (median 1856, interquartile range [IQR] 761-3500). Specimen numbers culture-positive for MTBC or NTM ranged from 0 to 1895 (median 46, IQR 17-116), and from 0 to 833 (median 30, IQR 13-71), respectively. Numbers of performed first-line susceptibility tests varied between 3 and 1400 (median 36, IQR 28-78). Eight laboratories performed DST for NTM. Also, 26.9% of all laboratories did not offer rapid genotypic DST (gDST) from primary samples.CONCLUSION: The landscape of diagnostic mycobacteriology in Germany is highly heterogenic with considerable variations in sample numbers and testing methodologies. Shortcomings exist with respect to fluorochrome staining of primary samples, rapid gDST of MTBC, and DST of NTM. National guidelines need to be adapted accordingly.


Subject(s)
Bacteriological Techniques/methods , Laboratories/statistics & numerical data , Mycobacterium Infections, Nontuberculous/diagnosis , Tuberculosis/diagnosis , Germany , Humans , Microbial Sensitivity Tests , Microscopy , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/isolation & purification , Nontuberculous Mycobacteria/drug effects , Nontuberculous Mycobacteria/isolation & purification , Surveys and Questionnaires , Tuberculosis/microbiology
7.
Clin Microbiol Infect ; 25(3): 379.e1-379.e7, 2019 Mar.
Article in English | MEDLINE | ID: mdl-29906595

ABSTRACT

OBJECTIVES: To determine MIC distributions for Mycobacterium chimaera, Mycobacterium intracellulare, Mycobacterium colombiense and Mycobacterium avium, and to derive tentative epidemiological cut-off (ECOFF) values. METHODS: A total of 683 bacterial isolates (M. chimaera, n = 203; M. intracellulare, n = 77; M. colombiense, n = 68; M. avium, n = 335) from 627 patients were tested by broth microdilution according to CLSI protocol M24-A2 on Sensititre RAPMYCOI plates. MICs were interpreted based on CLSI breakpoints for clarithromycin, and tentative breakpoints for amikacin, moxifloxacin and linezolid. Tentative ECOFFs were determined by visual approximation and the ECOFFinder algorithm. RESULTS: Modal MIC, MIC50 and MIC90 values were within ± one dilution step from the respective aggregated data set for 47/48 (97.9%), 48/48 (100%) and 48/48 (100%) species-drug combinations. Clarithromycin wild-type populations were mostly classified as susceptible (MIC90 4-8 mg/L; S ≤8 mg/L). Rifabutin MICs were lower than those of rifampicin. Tentative moxifloxacin, linezolid and amikacin breakpoints split wild-type populations. No ECOFFs could be set for rifampicin, ethambutol, ciprofloxacin, isoniazid, trimethoprim/sulfamethoxazole and doxycycline because of truncation of MIC distributions. Agreement between the visually determined and the modelled 97.5% ECOFFs was 90.9%. All 99.0% ECOFFs were one titre step higher than by visual approximation. CONCLUSIONS: Drug susceptibility patterns of M. chimaera are comparable to those of closely related species. Except for clarithromycin, breakpoints for Mycobacterium avium-intracellulare complex should be re-evaluated. Statistical determination of the 99.0% ECOFF may be superior to visual approximation.


Subject(s)
Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests/statistics & numerical data , Mycobacterium avium Complex/drug effects , Mycobacterium avium/drug effects , Drug Resistance, Bacterial/drug effects , Humans , Microbial Sensitivity Tests/standards , Mycobacterium avium/isolation & purification , Mycobacterium avium Complex/isolation & purification , Mycobacterium avium-intracellulare Infection/microbiology
8.
Clin Infect Dis ; 69(2): 268-277, 2019 07 02.
Article in English | MEDLINE | ID: mdl-30329017

ABSTRACT

BACKGROUND: Gut dysbiosis has been suggested as a major risk factor for the development of late-onset sepsis (LOS), a main cause of mortality and morbidity in preterm infants. We aimed to assess specific signatures of the gut microbiome, including metabolic profiles, in preterm infants <34 weeks of gestation preceding LOS. METHODS: In a single-center cohort, fecal samples from preterm infants were prospectively collected during the period of highest vulnerability for LOS (days 7, 14, and 21 of life). Following 16S rRNA gene profiling, we assessed microbial community function using microbial metabolic network modeling. Data were adjusted for gestational age and use of probiotics. RESULTS: We studied stool samples from 71 preterm infants with LOS and 164 unaffected controls (no LOS/necrotizing enterocolitis). In most cases, the bacteria isolated in diagnostic blood culture corresponded to the genera in the gut microbiome. LOS cases had a decelerated development of microbial diversity. Before onset of disease, LOS cases had specific gut microbiome signatures with higher abundance of Bacilli (specifically coagulase-negative Staphylococci) and a lack of anaerobic bacteria. In silico modeling of bacterial community metabolism suggested accumulation of the fermentation products ethanol and formic acid in LOS cases before the onset of disease. CONCLUSIONS: Intestinal dysbiosis preceding LOS is characterized by an accumulation of Bacilli and their fermentation products and a paucity of anaerobic bacteria. Early microbiome and metabolic patterns may become a valuable biomarker to guide individualized prevention strategies of LOS in highly vulnerable populations.


Subject(s)
Dysbiosis/complications , Gastrointestinal Microbiome , Infant, Premature , Metabolome , Neonatal Sepsis/pathology , Anaerobiosis , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Feces/chemistry , Feces/microbiology , Humans , Infant , Infant, Newborn , Male , Metabolomics , Metagenomics , Phylogeny , Prospective Studies , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
9.
ACS Appl Mater Interfaces ; 10(16): 13720-13728, 2018 Apr 25.
Article in English | MEDLINE | ID: mdl-29608054

ABSTRACT

Replacing the liquid electrolyte in conventional lithium-ion batteries with thin-film solid-state lithium-ion conductors is a promising approach for increasing energy density, lifetime, and safety. In particular, Li7La3Zr2O12 is appealing due to its high lithium-ion conductivity and wide electrochemical stability window. Further insights into thin-film processing of this material are required for its successful integration into solid-state batteries. In this work, we investigate the phase evolution of Li7-3 xGa xLa3Zr2O12 in thin films with various amounts of Li and Ga for stabilizing the cubic phase. Through this work, we gain valuable insights into the crystallization processes unique to thin films and are able to form dense Li7-3 xGa xLa3Zr2O12 layers stabilized in the cubic phase with high in-plane lithium-ion conductivities of up to 1.6 × 10-5 S cm-1 at 30 °C. We also note the formation of cubic Li7La3Zr2O12 at the relatively low temperature of 500 °C.

11.
Pneumologie ; 71(4): 207-214, 2017 Apr.
Article in German | MEDLINE | ID: mdl-28407674

ABSTRACT

Study purpose According to the Robert Koch Institute, 84,700 people in Germany suffer from HIV infection. One-third of the affected persons is over 50 years old. In Germany, community-acquired pneumonia (CAP) is a widespread disease with more than 250,000 cases per year. Incidence and mortality increase with the age of the affected individuals. For this reason, diagnostic and therapeutic strategies are needed to guide medical care of HIV-infected patients presenting with CAP. Methodology HIV therapists were interviewed about their diagnostic approach, risk stratification strategy and therapeutic approach to HIV-associated community-acquired pneumonia (HIV +/CAP) using a questionnaire. 56 completed questionnaires were analysed. Results Half of the respondents reported that CAP occurred in 1 to 5 % of HIV-infected individuals per year. This indicates an estimated number of up to 4200 HIV +/CAP cases per year in Germany - a much higher number than expected from the literature. 58.9 % of respondents considered that the pathogenic spectrum did not differ in HIV +/CAP from non-HIV/CAP. 80.3 % of respondents applied the same antibiotic regimens in HIV +/CAP as used in patients with non-HIV/CAP. Conclusion Even though over 40 % of HIV therapists agree that the pathogenic spectrum of HIV +/CAP differs from that of non-HIV/CAP, over 80 % of therapists managed these patients in accordance with the S3-guidelines for non-immunocompromised CAP-patients, because specific guidelines for the treatment of HIV +/CAP are lacking. Since specific data on the aetiology and the clinical course of HIV +/CAP depending, for instance, on CD4-count and antiretroviral therapy are missing, we feel that the clinical course of HIV +/CAP should be further analysed in the context of prospective cohort studies.


Subject(s)
Community-Acquired Infections/diagnosis , Community-Acquired Infections/drug therapy , HIV Infections/epidemiology , Pneumonia, Bacterial/diagnosis , Pneumonia, Bacterial/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Antiviral Agents/therapeutic use , Child , Child, Preschool , Community-Acquired Infections/epidemiology , Comorbidity , Female , Germany/epidemiology , HIV Infections/diagnosis , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Pneumonia, Bacterial/epidemiology , Practice Patterns, Physicians'/statistics & numerical data , Risk Factors , Treatment Outcome , Young Adult
12.
Int J Tuberc Lung Dis ; 21(2): 236-243, 2017 02 01.
Article in English | MEDLINE | ID: mdl-28234091

ABSTRACT

BACKGROUND: Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality, and chronic obstructive pulmonary disease (COPD) is a frequent comorbidity. The bacterial aetiology of CAP-COPD and its possible associations with serum markers and mortality are incompletely understood. OBJECTIVES: 1) To assess the bacterial aetiology of CAP only and CAP-COPD, and 2) to study the association between bacterial aetiology, empirical antibiotic treatment, serum markers and mortality. METHODS: Of 1288 patients with CAP (57.0% males, age 59.0 years ± 18.5), 262 (20.3%) fulfilled the diagnostic criteria for COPD. Differences between subgroups were investigated using univariate analyses and corrected for multiple comparisons. RESULTS: Streptococcus pneumoniae was the most common pathogen (30.8% CAP only vs. 26.0% CAP-COPD, not significant). Haemophilus influenzae was significantly more frequent in CAP-COPD (5.6% CAP only vs. 26.0% CAP-COPD, P < 0.001). The number given adequate empirical antibiotic treatment was comparable (83.3% CAP only vs. 83.6% CAP-COPD, P > 0.05). The CAP-COPD group had worse CURB-65 and partial pressure of arterial oxygen levels than the CAP only group (P < 0.001). Partial pressure of arterial carbon dioxide levels were increased in CAP-COPD patients without pathogen detection (P < 0.001). Short- (P = 0.011) and long-term mortality (P = 0.006) were highest in CAP-COPD without pathogen detection. CONCLUSION: It is important to identify COPD patients with CAP. In particular, those without bacterial pathogen detection have more severe CAP and are at higher risk of dying. Better understanding of the aetiology could contribute to improved management and treatment of CAP in COPD patients.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Community-Acquired Infections/epidemiology , Pneumonia, Bacterial/epidemiology , Pulmonary Disease, Chronic Obstructive/complications , Adult , Bacteria/isolation & purification , Biomarkers/blood , Carbon Dioxide/blood , Community-Acquired Infections/microbiology , Community-Acquired Infections/mortality , Female , Germany/epidemiology , Humans , Male , Middle Aged , Pneumonia, Bacterial/microbiology , Pneumonia, Bacterial/mortality , Pulmonary Disease, Chronic Obstructive/mortality
13.
J Biomech ; 49(14): 3208-3215, 2016 10 03.
Article in English | MEDLINE | ID: mdl-27553847

ABSTRACT

The standard method for specifying target responses for human surrogates, such as crash test dummies and human computational models, involves developing a corridor based on the distribution of a set of empirical mechanical responses. These responses are commonly normalized to account for the effects of subject body shape, size, and mass on impact response. Limitations of this method arise from the normalization techniques, which are based on the assumptions that human geometry linearly scales with size and in some cases, on simple mechanical models. To address these limitations, a new method was developed for corridor generation that applies principal component (PC) analysis to align response histories. Rather than use normalization techniques to account for the effects of subject size on impact response, linear regression models are used to model the relationship between PC features and subject characteristics. Corridors are generated using Monte Carlo simulation based on estimated distributions of PC features for each PC. This method is applied to pelvis impact force data from a recent series of lateral impact tests to develop corridor bounds for a group of signals associated with a particular subject size. Comparing to the two most common methods for response normalization, the corridors generated by the new method are narrower and better retain the features in signals that are related to subject size and body shape.


Subject(s)
Mechanical Phenomena , Principal Component Analysis , Biomechanical Phenomena , Humans , Monte Carlo Method
14.
Nanoscale ; 8(31): 14746-53, 2016 Aug 21.
Article in English | MEDLINE | ID: mdl-27455404

ABSTRACT

Garnet-based Al-doped Li7La3Zr2O12 has the potential to be used as a solid state electrolyte for future lithium microbattery architectures, due to its relatively high Li(+) conductivity and stability against Li. Through this work, a model experiment is presented in which the effect of post-lithiation on phase formation and chemical stability is studied for pulsed laser deposited Al-doped Li7La3Zr2O12 thin films on MgO substrates. We report the implications of the newly suggested post-lithiation route for films with thicknesses between 90 and 380 nm. The phase changes from cubic, to a mix of cubic and tetragonal Li7La3Zr2O12, to a cubic Li7La3Zr2O12 and La2Zr2O7 containing film is accompanied by a reduction in the degree of de-wetting as the thickness increases. This study reveals that the thicker, dense, and continuous films remain predominantly in a mixed phase containing cubic Li7La3Zr2O12 and the lithium free La2Zr2O7 phase whereas the thinner, de-wetted films exhibit improved lithium incorporation resulting in the absence of the lithium free phase. For tuning the electrical conductivity and effective use of these structures in future batteries, understanding this material system is of great importance as the chemical stability of the cubic Li7La3Zr2O12 phase in the thin film system will control its effective use. We report a conductivity of 1.2 × 10(-3) S cm(-1) at 325 °C for a 380 nm thick solid state electrolyte film on MgO for potential operation in future all solid state battery assemblies.

15.
Clin Exp Immunol ; 185(3): 382-91, 2016 09.
Article in English | MEDLINE | ID: mdl-27324468

ABSTRACT

Recent data suggest a possible relationship between cystic fibrosis (CF) pharmacotherapy, Aspergillus fumigatus colonization (AC) and/or allergic bronchopulmonary aspergillosis (ABPA). The aim of this study was to determine if anti-fungal defence mechanisms are influenced by CF pharmacotherapy, i.e. if (1) neutrophils form CF and non-CF donors differ in their ability to produce chitotriosidase (CHIT-1); (2) if incubation of isolated neutrophils with azithromycin, salbutamol, prednisolone or rhDNase might influence the CHIT-1 activity; and (3) if NETosis and neutrophil killing efficiency is influenced by rhDNase. Neutrophils were isolated from the blood of CF patients (n = 19; mean age 26·8 years or healthy, non-CF donors (n = 20; 38·7 years) and stimulated with phorbol-12-myristate-13-acetate (PMA), azithromycin, salbutamol, prednisolone or rhDNase. CHIT-1 enzyme activity was measured with a fluorescent substrate. NETosis was induced by PMA and neutrophil killing efficiency was assessed by a hyphae recovery assay. Neutrophil CHIT-1 activity was comparable in the presence or absence of PMA stimulation in both CF and non-CF donors. PMA stimulation and preincubation with rhDNase increased CHIT-1 activity in culture supernatants from non-CF and CF donors. However, this increase was significant in non-CF donors but not in CF patients (P < 0·05). RhDNase reduced the number of NETs in PMA-stimulated neutrophils and decreased the killing efficiency of leucocytes in our in-vitro model. Azithromycin, salbutamol or prednisolone had no effect on CHIT-1 activity. Stimulation of isolated leucocytes with PMA and treatment with rhDNase interfered with anti-fungal defence mechanisms. However, the impact of our findings for treatment in CF patients needs to be proved in a clinical cohort.


Subject(s)
Cystic Fibrosis/immunology , Deoxyribonucleases/therapeutic use , Hexosaminidases/metabolism , Neutrophils/enzymology , Neutrophils/pathology , Adolescent , Adult , Aged , Albuterol/pharmacology , Albuterol/therapeutic use , Aspergillus fumigatus/isolation & purification , Azithromycin/pharmacology , Azithromycin/therapeutic use , Bacteria/isolation & purification , Cystic Fibrosis/drug therapy , Cystic Fibrosis/microbiology , Deoxyribonucleases/genetics , Extracellular Traps/drug effects , Female , Fungi/isolation & purification , Hexosaminidases/analysis , Hexosaminidases/biosynthesis , Humans , Male , Middle Aged , Neutrophils/drug effects , Neutrophils/physiology , Phorbol Esters/pharmacology , Prednisolone/pharmacology , Prednisolone/therapeutic use , Sputum/microbiology , Young Adult
16.
Clin Exp Immunol ; 185(2): 219-27, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27163159

ABSTRACT

The predisposition of preterm neonates to invasive infection is, as yet, incompletely understood. Regulatory T cells (Tregs ) are potential candidates for the ontogenetic control of immune activation and tissue damage in preterm infants. It was the aim of our study to characterize lymphocyte subsets and in particular CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) Tregs in peripheral blood of well-phenotyped preterm infants (n = 117; 23 + 0 - 36 + 6 weeks of gestational age) in the first 3 days of life in comparison to term infants and adults. We demonstrated a negative correlation of Treg frequencies and gestational age. Tregs were increased in blood samples of preterm infants compared to term infants and adults. Notably, we found an increased Treg frequency in preterm infants with clinical early-onset sepsis while cause of preterm delivery, e.g. chorioamnionitis, did not affect Treg frequencies. Our data suggest that Tregs apparently play an important role in maintaining maternal-fetal tolerance, which turns into an increased sepsis risk after preterm delivery. Functional analyses are needed in order to elucidate whether Tregs have potential as future target for diagnostics and therapeutics.


Subject(s)
Infant, Premature, Diseases/immunology , Infant, Premature/immunology , Sepsis/immunology , T-Lymphocytes, Regulatory/immunology , Adult , Amnion/microbiology , Chorioamnionitis/immunology , Female , Forkhead Transcription Factors/blood , Gestational Age , Humans , Immune Tolerance , Infant , Infant, Newborn , Lymphocyte Subsets/cytology , Lymphocyte Subsets/immunology , Pregnancy , Sepsis/microbiology
17.
Phys Chem Chem Phys ; 18(17): 12278-88, 2016 04 28.
Article in English | MEDLINE | ID: mdl-27080470

ABSTRACT

Chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) are emerging CO2 capture technologies that could reduce appreciably the costs associated with the capture of CO2. In CLC and CLOU, the oxygen required to combust a hydrocarbon is provided by a solid oxygen carrier. Among the transition metal oxides typically considered for CLC and CLOU, copper oxide (CuO) stands out owing to its high oxygen carrying capacity, exothermic reduction reactions and fast reduction kinetics. However, the low Tammann (sintering) temperature of CuO is a serious drawback. In this context, it has been proposed to support CuO on high Tammann temperature and low cost alumina (Al2O3), thus, reducing the morphological changes occurring over multiple CLC or CLOU redox cycles and stabilizing, in turn, the high activity of CuO. However, in CuO-Al2O3 systems, phase stabilization and avoiding the formation of the CuAl2O4 spinel is key to obtaining a material with a high redox stability and activity. Here, we report a Na(+) doping strategy to phase stabilize Al2O3-supported CuO, yielding in turn an inexpensive material with a high redox stability and CO2 capture efficiency. We also demonstrate that doping CuO-Al2O3 with Na(+) improves the oxygen uncoupling characteristics and coke resistance of the oxygen carriers. Utilizing in situ and ex situ X-ray absorption spectroscopy (XAS), the local structure of Cu and the reduction pathways of CuO were determined as a function of the Na(+) content and cycle number. Finally, using 4-point conductivity measurements, we confirm that doping of Al2O3-supported CuO with Na(+) lowers the activation energy for charge transport explaining conclusively the improved redox characteristics of the new oxygen carriers developed.

18.
J Biomech ; 48(15): 4173-4177, 2015 Nov 26.
Article in English | MEDLINE | ID: mdl-26549763

ABSTRACT

An updated technique to develop biofidelity response corridors (BRCs) is presented. BRCs provide a representative range of time-dependent responses from multiple experimental tests of a parameter from multiple biological surrogates (often cadaveric). The study describes an approach for BRC development based on previous research, but that includes two key modifications for application to impact and accelerative loading. First, signal alignment conducted prior to calculation of the BRC considers only the loading portion of the signal, as opposed to the full time history. Second, a point-wise normalization (PWN) technique is introduced to calculate correlation coefficients between signals. The PWN equally weighs all time points within the loading portion of the signals and as such, bypasses aspects of the response that are not controlled by the experimentalist such as internal dynamics of the specimen, and interaction with surrounding structures. An application of the method is presented using previously-published thoracic loading data from 8 lateral sled PMHS tests conducted at 8.9m/s. Using this method, the mean signals showed a peak lateral load of 8.48kN and peak chest acceleration of 86.0g which were similar to previously-published research (8.93kN and 100.0g respectively). The peaks occurred at similar times in the current and previous studies, but were delayed an average of 2.1ms in the updated method. The mean time shifts calculated with the method ranged from 7.5% to 9.5% of the event. The method may be of use in traditional injury biomechanics studies and emerging work on non-horizontal accelerative loading.


Subject(s)
Spine/physiology , Thorax/physiology , Acceleration , Accidents , Aged , Biomechanical Phenomena , Cadaver , Female , Humans , Male , Middle Aged
19.
Phys Chem Chem Phys ; 17(28): 18613-20, 2015 Jul 28.
Article in English | MEDLINE | ID: mdl-26119755

ABSTRACT

The crystallization kinetics of amorphous 3 and 8 mol% yttria stabilized zirconia (3YSZ and 8YSZ) thin films grown by pulsed laser deposition (PLD), spray pyrolysis and dc-magnetron sputtering are explored. The deposited films were heat treated up to 1000 °C ex situ and in situ in an X-ray diffractometer. A minimum temperature of 275 °C was determined at which as-deposited amorphous PLD grown 3YSZ films fully crystallize within five hours. Above 325 °C these films transform nearly instantaneously with a high degree of micro-strain when crystallized below 500 °C. In these films the t'' phase crystallizes which transforms at T > 600 °C to the t' phase upon relaxation of the micro-strain. Furthermore, the crystallization of 8YSZ thin films grown by PLD, spray pyrolysis and dc-sputtering are characterized by in situ XRD measurements. At a constant heating rate of 2.4 K min(-1) crystallization is accomplished after reaching 800 °C, while PLD grown thin films were completely crystallized already at ca. 300 °C.

20.
Infect Immun ; 83(7): 2651-60, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25895972

ABSTRACT

Chlamydia pneumoniae is a Gram-negative bacterium that causes acute or chronic respiratory infections. As obligate intracellular pathogens, chlamydiae efficiently manipulate host cell processes to ensure their intracellular development. Here we focused on the interaction of chlamydiae with the host cell transcription factor activator protein 1 (AP-1) and its consequence on chlamydial development. During Chlamydia pneumoniae infection, the expression and activity of AP-1 family proteins c-Jun, c-Fos, and ATF-2 were regulated in a time- and dose-dependent manner. We observed that the c-Jun protein and its phosphorylation level significantly increased during C. pneumoniae development. Small interfering RNA knockdown of the c-Jun protein in HEp-2 cells reduced the chlamydial load, resulting in smaller inclusions and significantly lower chlamydial recovery. Furthermore, inhibition of the c-Jun-containing AP-1 complexes using tanshinone IIA changed the replicative infection phenotype into a persistent one. Tanshinone IIA-dependent persistence was characterized by smaller, aberrant inclusions, a strong decrease in the chlamydial load, and significantly reduced chlamydial recovery, as well as by the reversibility of the reduced recovery after the removal of tanshinone IIA. Interestingly, not only was tanshinone IIA treatment accompanied by a significant decrease of ATP levels, but fluorescence live cell imaging analysis by two-photon microscopy revealed that tanshinone IIA treatment also resulted in a decreased fluorescence lifetime of protein-bound NAD(P)H inside the chlamydial inclusion, indicating that chlamydial reticulate bodies have decreased metabolic activity. In all, these data demonstrate that the AP-1 transcription factor is involved in C. pneumoniae development, with tanshinone IIA treatment resulting in persistence.


Subject(s)
Chlamydophila pneumoniae/growth & development , Gene Expression Regulation, Bacterial , Hepatocytes/microbiology , Hepatocytes/physiology , Host-Pathogen Interactions , Transcription Factor AP-1/metabolism , Transcription, Genetic , Bacterial Load , Hep G2 Cells , Humans
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