| 1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Abednazari, Hossein, 1959-, et al.
(author)
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Hepatocyte growth factor is a better indicator of therapeutic response than C-reactive protein within the first day of treatment in pneumonia
- 2006
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In: Chemotherapy. - : S. Karger AG. - 0009-3157 .- 1421-9794. ; 52:5, s. 260-263
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Journal article (peer-reviewed)abstract
- Acute bacterial infectious diseases are mostly treated empirically at admission before the culture results are available. According to the risk for serious complications in the case of therapeutic failure, it is important to evaluate the therapy results and change to a more appropriate antibiotic regime as soon as possible. In the present study, 40 patients with X-ray-verified community-acquired pneumonia were examined and blood specimens were collected before and within 24 h of treatment. Body temperature, C-reactive protein (CRP) and hepatocyte growth factor (HGF) were investigated. Thirty-two patients received an appropriate initial antibiotic therapy regarding clinical outcome, but in 8 patients the treatment was changed because of therapy failure. Changes of HGF levels after 18–24 h of treatment could predict the therapeutic results accurately in 38 of 40 cases (sensitivity 100%, specificity 94%, positive likelihood ratio 16.0). HGF was significantly better to predict therapy outcome than CRP (p < 0.0001).
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| 3. |
- Nayeri, Fariba, 1958-, et al.
(author)
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Hepatocyte growth factor (HGF) in fecal samples : rapid detection by surface plasmon resonance
- 2005
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In: BMC Gastroenterology. - 1471-230X. ; 5:13
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Journal article (peer-reviewed)abstract
- BackgroundThe development of biosensors, based on surface plasmon resonance (SPR) technology, enables monitoring of a variety of biospecific interactions without the need for chemical-, biological- or radiological-labelled reagents.MethodWe utilised SPR to detect hepatocyte growth factor (HGF) in reconstituted faecal samples and studied samples from patients with infectious gastroenteritis (n = 20) and normal controls (n = 10). Mouse anti-human HGF monoclonal antibodies and recombinant human HGF receptor (c-Met)/Fc chimera were immobilised in flow cells of a CM5 biosensor chip.ResultsWe found that infectious gastroenteritis produced a higher signal response compared to controls, due to binding of HGF to monoclonal anti-HGF antibody as well as binding of HGF to c-Met receptor (p < 0.01). The SPR signal response correlated with results from ELISA (r = 72%, p > 0.001). The signal response decreased significantly (p < 0.05) when samples were diluted with dextran, because of reduction in both specific as well as unspecific binding of HGF to dextran. The decrease in the specific response might imply that the dextran- binding site for HGF overlaps with the antibody binding epitope, or that dextran binding induces a conformational change of the HGF molecule. Bands corresponding to HGF were found by gel electrophoresis of purified faeces in an affinity chromatography column immobilised by HGF ligands.ConclusionDetermination of HGF by SPR might be beneficial in diagnosis of acute situations that present with symptoms of gastroenteritis and may, possibly, guide appropriate medical treatments. This is to our knowledge the first report on the use of SPR for detection of HGF in faeces samples.
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| 4. |
- Xu, Junyang, et al.
(author)
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Apoptotic eosinophils in sputum from asthmatic patients correlate negatively with levels of IL-5 and eotaxin
- 2007
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In: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 101:7, s. 1447-1454
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Journal article (peer-reviewed)abstract
- Background: Eosinophilic inflammation of the airways is a key characteristic of asthma. A defect in eosinophil apoptosis might contribute to the chronic tissue eosinophilia associated with asthma. Objective: Our purpose was to examine whether the occurrence of apoptotic eosinophils in induced sputum from asthmatic patients correlate with interleukin (IL)-5 and eotaxin. Methods: Thirty stable and 30 exacerbated asthmatic patients were recruited. Twenty healthy subjects were enrolled as a control group. Induced sputum was obtained from asthmatic patients and from control subjects. The number of apoptotic eosinophils in sputum was assessed by flow cytometry. In sputum supernatant, eosinophil cationic protein (ECP) was measured by sensitive radioimmunoassay, and IL-5 and eotaxin by sandwich enzyme linked immunosorbant assay. Results: Levels of eosinophils, apoptotic eosinophils, IL-5, ECP and eotaxin from asthmatic patients were higher than those from healthy subjects. Thirty exacerbated asthmatics showed higher proportions of eosinophils (median 29.3%, range 13.4%-40.9%), more detectable levels of IL-5 (50.44, 32.99-67.01 pg/ml) and eotaxin (644.6, 197.4-937.7 pg/ml) in their sputum than the patients with stable asthma (P < 0.05). There were significant inverse correlations between the levels of sputum IL-5 and the proportion of sputum eosinophil apoptosis in patients with exacerbated and stable asthma (r = - 0.85 and -0.79, P < 0.01 and P < 0.05, respectively). Also inverse correlations were found between the levels of eotaxin and the proportion of sputum eosinophil apoptosis in exacerbated (r = - 0.85, P < 0.01), or stable asthma (r = - 0.69, P < 0.05). Additional positive corrlations between the levels of sputum IL-5 and eotaxin in either exacerbatated (r = 0.93, P < 0.01) or stable asthma (r = 0.82, P < 0.05) were observed. Conclusions: Apoptosis of eosinophils might be suppressed by proinflammatory cytokines and chemokines such as IL-5 and eotaxin leading to their accumulation in the lung. Stimulation of eosinophils in airway with IL-5 and eotaxin may play a crucial role in allergic inflammation. © 2007 Elsevier Ltd. All rights reserved.
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