SciCombinator

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Concept: Marker

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In recent decades, fresh and minimally processed produce items have been associated with an increasing proportion of foodborne illnesses. Most pathogens associated with fresh produce are enteric (fecal) in origin, and contamination can occur anywhere along the farm-to-fork chain. Microbial source tracking (MST) is a tool developed in the environmental microbiology field to identify and quantify the dominant source(s) of fecal contamination. This study investigated the utility of an MST method based on Bacteroidales 16S rDNA sequences as a means of identifying potential fecal contamination, and its source, in the fresh produce production environment. The method was applied to rinses of fresh produce, source and irrigation waters, and harvester hand rinses collected over the course of one year from nine farms (growing tomatoes, jalapeño peppers, and cantaloupe) in Northern Mexico. Of 174 samples, 39% were positive for a universal Bacteroidales marker (AllBac), including 66% of samples from cantaloupe farms (3.6 log10 genome equivalence copies [GEC]/100 ml), 31% of samples from tomato farms (1.7 log10 GEC/100 ml), and 18% of samples from jalapeño farms (1.5 log10 GEC/100 ml). Of 68 AllBac-positive samples, 46% were positive for one of 3 human-specific markers (BFD, HF183, BVulg), and none were positive for a bovine-specific marker (BoBac). There was no statistically significant correlation between Bacteroidales and generic E. coli across all samples. This study provides evidence that Bacteroidales markers may serve as alternative indicators for fecal contamination in fresh produce production, allowing for determination of both general contamination and that derived from the human host.

Concepts: Bacteria, Microbiology, Escherichia coli, Marker, Tomato, Identification, Mexico, Marker pen

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In this study we analyzed some aspects of the assessment of developmental delay in the zebrafish embryotoxicity/teratogenicity test and explored the suitability of acetylcholinesterase (AChE) activity as a biochemical marker and as a higher throughput alternative to morphological endpoints such as head-trunk angle, tail length and morphological score. Embryos were exposed from 4 to 52 h post-fertilization (hpf) to a selection of known embryotoxic/teratogen compounds (valproic acid, retinoic acid, caffeine, sodium salicylate, glucose, hydroxyurea, methoxyacetic acid, boric acid and paraoxon-methyl) over a concentration range. They were evaluated for AChE activity, head-trunk angle, tail length and several qualitative parameters integrated in a morphological score. In general, the different patterns of the concentration-response curves allowed distinguishing between chemicals that produced growth retardation (valproic and methoxyacetic acid) and chemicals that produced non-growth-delay related malformations. An acceptable correlation between the morphological score, AChE activity and head-trunk angle as markers of developmental delay was observed, being AChE activity particularly sensitive to detect delay in the absence of malformations.

Concepts: Enzyme, Embryo, Developmental biology, Chemistry, Marker

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OBJECTIVE: To evaluate the utility of near-infrared spectroscopy (NIRS) and transcranial Doppler (TCD) parameters as potential markers for amnestic mild cognitive impairment (aMCI). METHODS: By means of NIRS and TCD, noninvasive and inexpensive technologies, we studied 21 patients with aMCI (10 M and 11 F, 70.2±7.3years) and 10 age matched healthy controls. RESULTS: By means of NIRS, we found a significant mean decrease of tissue oxygen saturation of cortex microcirculation (TOI), - 27%, p<0.0005, on the temporal-parietal cortex of both side compared to the controls. By means of TCD, we found a significant mean increase of pulsatility index (PI), p<0.0007, of middle cerebral artery (MCA) of both side compared to the controls. Cerebrovascular risk factors were present in 81% of the aMCI patients. CONCLUSIONS: Our study reveals that the TOI reduction on the temporal-parietal cortex of both side and the increase of PI in both MCA are associated with a clinical diagnosis of aMCI patients. SIGNIFICANCE: The reduction of TOI may be considered a new marker for aMCI, especially when combined with the increase of PI in MCA.

Concepts: Blood, Temporal lobe, Cerebrum, Middle cerebral artery, Marker, Cultural studies, Near infrared spectroscopy

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The causes and development of lung fluid, as well as the integrity of the alveolar-capillary membrane at high altitude, are undefined. This study was conceived to see whether fluid accumulates within the lung with acute high altitude exposure, and whether this is associated with alveolar capillary membrane damage. We studied lung carbon monoxide diffusion (DLco), its components-membrane diffusion (DM) and capillary volume (Vc)-and alveolar volume (Va) measured in 43 healthy subjects in Milan (122m) and after 1 and 3 days at Capanna Regina Margherita (4559m). DLCO measurement was adjusted for hemoglobin and inspired oxygen. We also measured plasma Surfactant derived Protein B (SPB) and Receptor of Advanced Glycation End-products (RAGE) as markers of alveolar-capillary membrane damage, and ultrasound lung comets as a marker of extravascular lung water. 21 subjects received acetazolamide and 22 placebo. Dlco was lower at Capanna Regina Margherita (day 1: 24.3±4.7mL/mmHg/min and day 3: 23.6±5.4), than in Milan (25.8±5.5; p<0.001 vs. day 1 and 3) due to Dm reduction (Milan: 50.5±14.6mL/mmHg/min, Capanna Regina Margherita day 1: 45.1±11.5, day 3: 43.2±13.9; p<0.05 Milan vs. day 3) with a partially compensatory Vc increase (Milan: 96±37mL, Capanna Regina Margherita day 1: 152±66, day 3: 153±59; p<0.001 Milan vs. day 1 and day 3). Acetazolamide did not prevent the fall in Dlco albeit, between day 1 and 3, such a trend was observed. Regardless of treatment lung comets increased from 0 to 7.2±3.6 (p<0.0001). SPB and RAGE were unchanged. Lung fluid increased at high altitude without evidence from plasma measurements, supporting alveolar-capillary damage. Clinical trial registration: Eudract Number [2010-019986-27].

Concepts: Hemoglobin, Protein, Oxygen, Carbon dioxide, Measurement, Carbon monoxide, Marker, Altitude sickness

27

A method that enables high precision extraction of transmission electron microscope (TEM) specimens in low contrast materials has been developed. The main idea behind this work is to produce high contrast markers on both sides of and close to the area of interest. The markers are filled during the depositing of the protective layer. The marker material can be of either Pt or C depending on which one gives the highest contrast. It is thereby possible to distinguish the location of the area of interest during focused ion beam (FIB) milling and ensure that the TEM sample is extracted precisely at the desired position. This method is generally applicable and enables FIB/scanning electron microscope users to make high quality TEM specimens from small features and low contrast materials without a need for special holders. We explain the details of this method and illustrate its potential by examples from three different types of materials.

Concepts: Electron, Electron microscope, Scientific techniques, Transmission electron microscopy, Marker, Scanning electron microscope, Electron microscopy, Focused ion beam

24

Extent of shape change (ESC), hypotonic shock response (HSR), the adhesive glycoprotein CD62P and lactate have been widely used as in vitro quality makers of platelet concentrates. Our aim was to evaluate soluble glycoprotein V (sGPV) as a platelet in vitro activation marker for platelet concentrates. Data were obtained from different validations during a twelve-year period.

Concepts: Marker

22

Current flow-cytometric plasma cell (PC) gating is based on CD138, CD38 and CD45 expression. CD138 is known for variable expression and loss during storage and processing. Introduction of anti-CD38 and anti-CD138 monoclonal-antibody therapies has limited the use of these markers during follow-up. Hence, additional reliable PC-gating markers are required. Recently, CD229 has been claimed as an alternative PC-gating marker. However, these studies are limited to a small cohort of samples. We evaluated the utility of CD229 as a new PC-gating marker in routine laboratory practice.

Concepts: DNA, Medicine, Flow cytometry, Marker, Expression, Marker pen

14

Obstructive sleep apnea (OSA) is a common disease, distinguished by recurrent episodes of upper airway obstruction during sleep, with an inflammatory component. C-reactive protein (CRP) and high-sensitivity C-reactive protein (hs-CRP) are markers of systemic inflammation and may serve as biomarkers of OSA.

Concepts: Inflammation, Sleep apnea, Obstructive sleep apnea, Marker, C-reactive protein, Obstructive lung disease, Abnormal respiration, Acute-phase protein

10

Many athletes, coaches, and support staff are taking an increasingly scientific approach to both designing and monitoring training programs. Appropriate load monitoring can aid in determining whether an athlete is adapting to a training program and in minimizing the risk of developing non-functional overreaching, illness, and/or injury. In order to gain an understanding of the training load and its effect on the athlete, a number of potential markers are available for use. However, very few of these markers have strong scientific evidence supporting their use, and there is yet to be a single, definitive marker described in the literature. Research has investigated a number of external load quantifying and monitoring tools, such as power output measuring devices, time-motion analysis, as well as internal load unit measures, including perception of effort, heart rate, blood lactate, and training impulse. Dissociation between external and internal load units may reveal the state of fatigue of an athlete. Other monitoring tools used by high-performance programs include heart rate recovery, neuromuscular function, biochemical/hormonal/immunological assessments, questionnaires and diaries, psychomotor speed, and sleep quality and quantity. The monitoring approach taken with athletes may depend on whether the athlete is engaging in individual or team sport activity; however, the importance of individualization of load monitoring cannot be over emphasized. Detecting meaningful changes with scientific and statistical approaches can provide confidence and certainty when implementing change. Appropriate monitoring of training load can provide important information to athletes and coaches; however, monitoring systems should be intuitive, provide efficient data analysis and interpretation, and enable efficient reporting of simple, yet scientifically valid, feedback.

Concepts: Scientific method, Understanding, Measurement, Science, Heart rate, Marker, Units of measurement, Marker pen

9

In an ongoing, open-label, phase 1b study on the intrathecal administration of rituximab for progressive multiple sclerosis, an intraventricular catheter was inserted for drug delivery. The objective of this study was to characterize the limited white matter axonal injury evoked by catheter insertion by analyzing a panel of markers for tissue damage in CSF and serum.

Concepts: Quantum mechanics, Multiple sclerosis, Marker