Increasing Signal Intensity of Fluorescent Oligo-Labeled Antibodies to Enable Combination Multiplexing.

Full-spectrum flow cytometry has increased antibody-based multiplexing, yet further increases remain potentially impactful. We recently proposed how fluorescence multiplexing using spectral imaging and combinatorics (MuSIC) could do so using tandem dyes and an oligo-based antibody labeling method. In this work, we found that such labeled antibodies had significantly lower signal intensities than conventionally labeled antibodies in human cell experiments. To improve signal intensity, we tested moving the fluorophores from the original external (ext.) 5' or 3' end-labeled orientation to internal (int.) fluorophore modifications. Cell-free spectrophotometer measurements showed a ∼6-fold signal intensity increase of the new int. configuration compared to the previous ext. configuration. Time-resolved fluorescence and fluorescence correlation spectroscopy showed that the ∼3-fold brightness difference is due to static quenching most likely by the oligo or solution in the ext. configuration. Spectral flow cytometry experiments using peripheral blood mononuclear cells show int. MuSIC probe-labeled antibodies (i) retained increased signal intensity while having no significant difference in the estimated % of CD8+ lymphocytes and (ii) labeled with Atto488, Atto647, and Atto488/647 combinations can be demultiplexed in triple-stained samples. The antibody labeling approach is general and can be broadly applied to many biological and diagnostic applications where spectral detection is available.

Increasing Signal Intensity of Fluorescent Oligo-Labeled Antibodies.

While full-spectrum flow cytometry has increased antibody-based multiplexing, yet further increases remain potentially impactful. We recently proposed how fluorescence Multiplexing using Spectral Imaging and Combinatorics (MuSIC) could do so using tandem dyes and an oligo-based antibody labeling method. In this work, we found that such labeled antibodies had significantly lower signal intensity than conventionally-labeled antibodies in human cell experiments. To improve signal intensity, we tested moving the fluorophores from the original external (ext.) 5' or 3' end-labeled orientation to internal (int.) fluorophore modifications. Cell-free spectrophotometer measurements showed a ~6-fold signal intensity increase of the new int. configuration compared to the previous ext. configuration. Time-resolved fluorescence spectroscopy and fluorescence correlation spectroscopy showed that ~3-fold brightness difference is due to static quenching. Spectral flow cytometry experiments using peripheral blood mononuclear cells stained with anti-CD8 antibodies showed that int. MuSIC probe-labeled antibodies have signal intensity equal to or greater than conventionally-labeled antibodies with similar estimated proportion of CD8+ lymphocytes. The antibody labeling approach is general and can be broadly applied to many biological and diagnostic applications.

Theory for High-Throughput Genetic Interaction Screening.

Systematic, genome-scale genetic screens have been instrumental for elucidating genotype-phenotype relationships, but approaches for probing genetic interactions have been limited to at most ∼100 pre-selected gene combinations in mammalian cells. Here, we introduce a theory for high-throughput genetic interaction screens. The theory extends our recently developed Multiplexing using Spectral Imaging and Combinatorics (MuSIC) approach to propose ∼105 spectrally unique, genetically encoded MuSIC barcodes from 18 currently available fluorescent proteins. Simulation studies based on constraints imposed by spectral flow cytometry equipment suggest that genetic interaction screens at the human genome-scale may be possible if MuSIC barcodes can be paired to guide RNAs. While experimental testing of this theory awaits, it offers transformative potential for genetic perturbation technology and knowledge of genetic function. More broadly, the availability of a genome-scale spectral barcode library for non-destructive identification of single cells could find more widespread applications such as traditional genetic screening and high-dimensional lineage tracing.

Serogroup identification, phenotypic detection of hemolysis and extended spectrum beta-lactamases of Escherichia coli isolated from psittacine of illegal wildlife trade in Fortaleza, Brazil / Identificação de sorogrupo e detecção fenotípica de betalactamase de espectro estendido e produção de hemolisina em Escherichia coli isoladas de psitacídeos do tráfico de animais silvestres em Fortaleza-CE

This study aimed to identify serogroups of Escherichia coli important for human health in isolates from psittacine of illegal wildlife trade in Ceará State. In addition, hemolysis and production of Extended Spectrum Beta-Lactamases (ESBL) was assessed in the isolates. A total of 78 E. coli strains isolated from different Psittaciformes species from a wildlife rehabilitation center in Fortaleza, Brazil. The isolates used in this study were previously identified and stored. Serogroup identification was performed using polyvalent sera for EPEC (O55, O111, O119, O114, O125, O86, O126, O127, O128), EIEC (O136, O124) and EHEC (O157). ESBL detection was performed with double disk synergy method. For hemolysis detection, isolates were inoculated in blood agar base enriched with ovine blood. Only 31 (39.7%) isolates were seropositive and the most frequent were O127, O114, O128 and O111. There was no agglutination for serogroups O55, O124, O136 or O157. Considering both seropositive and seronegative isolates, 9 (11.5%) and 35 (44.9%) presented hemolysis and ESBL production, respectively. In conclusion, the investigated psittacine from illegal wildlife trade hosted ESBL-producing E. coli strains and some belong to important serogroups often linked to severe human infections.(AU)

Este trabalho teve como objetivo identificar sorogrupos de E. coli importantes para a saúde humana, oriundos de psitacídeos provenientes do tráfico no estado do Ceará, assim como detectar atividade hemolítica e produção de betalactamase de espectro estendido (ESBL). Foram testadas 78 cepas de Escherichia coli provenientes de psitaciformes do Centro de Triagem de Animais Silvestres, Fortaleza, CE. Para a identificação dos sorogrupos, utilizaram-se soros polivalentes EPEC (O55, O111, O119, O114, O125, O86, O126, O127, O128), EIEC (O136, O124) e EHEC (O157). Para detecção de ESBL, as cepas foram submetidas ao método de aproximação de disco e, para a detecção de hemolisina, foram plaqueadas em ágar sangue base enriquecido com sangue de carneiro. No geral, 31 (39,7%) das amostras foram soropositivas. Os sorogrupos mais frequentemente detectados foram O127, O114, O128 e O111. Não houve positividade para os sorogrupos O55, O124, O136 e O157. Considerando-se as amostras sororreagentes e não sororreagentes, observou-se que nove (11,5%) e 35 (44,9%) cepas de E. coli apresentaram produção de hemolisinas e de ESBL, respectivamente. Em conclusão, constatou-se que psitacídeos provenientes do tráfico de animais silvestres albergam cepas de E. coli produtoras de ESBL e providas de importantes sorogrupos implicados em graves infecções humanas.(AU)

The longitudinal mental health impact of Fukushima nuclear disaster exposures and public criticism among power plant workers: the Fukushima NEWS Project study.

BACKGROUND: The Fukushima Daiichi and Daini Nuclear Power Plant workers experienced multiple stressors as both victims and onsite workers after the 2011 Great East Japan Earthquake and subsequent nuclear accidents. Previous studies found that disaster-related exposures, including discrimination/slurs, were associated with their mental health. Their long-term impact has yet to be investigated. METHOD: A total of 968 plant workers (Daiichi, n = 571; Daini, n = 397) completed self-written questionnaires 2-3 months (time 1) and 14-15 months (time 2) after the disaster (response rate 55.0%). Sociodemographics, disaster-related experiences, and peritraumatic distress were assessed at time 1. At time 1 and time 2, general psychological distress (GPD) and post-traumatic stress response (PTSR) were measured, respectively, using the K6 scale and Impact of Event Scale Revised. We examined multivariate covariates of time 2 GPD and PTSR, adjusting for autocorrelations in the hierarchical multiple regression analyses. RESULTS: Higher GPD at time 2 was predicted by higher GPD at time 1 (ß = 0.491, p < 0.001) and discrimination/slurs experiences at time 1 (ß = 0.065, p = 0.025, adjusted R 2 = 0.24). Higher PTSR at time 2 was predicted with higher PTSR at time 1 (ß = 0.548, p < 0.001), higher age (ß = 0.085, p = 0.005), and discrimination/slurs experiences at time 1 (ß = 0.079, p = 0.003, adjusted R 2 = 0.36). CONCLUSIONS: Higher GPD at time 2 was predicted by higher GPD and discrimination/slurs experience at time 1. Higher PTSR at time 2 was predicted by higher PTSR, higher age, and discrimination/slurs experience at time 1.

Serum pro-BDNF/BDNF as a treatment biomarker for response to docosahexaenoic acid in traumatized people vulnerable to developing psychological distress: a randomized controlled trial.

Our open-label pilot study showed that supplementation with docosahexaenoic acid (DHA) increased serum brain-derived neurotrophic factor (BDNF) levels and that there might be an association between changes in serum BDNF levels and reduced psychological distress. Animal research has indicated that a DHA-enriched diet increases BDNF in the brain. In this randomized double-blind controlled trial of severely injured patients vulnerable to posttraumatic stress disorder (PTSD) and depression, we examined whether DHA increases serum BDNF levels and whether changes in BDNF levels are associated with subsequent symptoms of PTSD and depression. Patients received 1470 mg per day of DHA plus 147 mg per day of eicosapentaenoic acid (EPA; n = 53) or placebo (n = 57) for 12 weeks. Serum levels of mature BDNF and precursor pro-BDNF at baseline and 12-week follow-up were measured using enzyme-linked immunosorbent assay kits. At 12 weeks, we used the Clinician-Administered PTSD Scale to assess PTSD symptoms and depressive symptoms by the Montgomery-Åsberg Depression Rating Scale. We found a significant increase in serum BDNF levels during the trial in the DHA and placebo groups with no interaction between time and group. Changes in BDNF levels were not associated with PTSD severity but negatively associated with depression severity (Spearman's ρ = -0.257, P = 0.012). Changes in pro-BDNF were also negatively associated with depression severity (Spearman's ρ = -0.253, P = 0.013). We found no specific effects of DHA on increased serum levels of BDNF and pro-BDNF; however, evidence in this study suggests that increased BDNF and pro-BDNF have a protective effect by minimizing depression severity.

The role of high-density lipoprotein cholesterol in risk for posttraumatic stress disorder: taking a nutritional approach toward universal prevention.

Several cross-sectional studies, but no prospective studies, have reported an association between an abnormal lipid profile and posttraumatic stress disorder (PTSD). We hypothesized that an abnormal lipid profile might predict risk for developing PTSD. In this prospective study, we analyzed data from 237 antidepressant-naïve severely injured patients who participated in the Tachikawa Cohort of Motor Vehicle Accident Study. High-density lipoprotein cholesterol (HDL-C) levels at baseline were significantly lower in patients with PTSD than those without PTSD at 6 months after motor vehicle accident (MVA) and were inversely associated with risk for PTSD. In contrast, triglycerides (TG) at baseline were significantly higher in patients with PTSD than in those without PTSD at 6 months post-MVA and were positively associated with risk for PTSD. There was no clear association between low-density lipoprotein cholesterol or total cholesterol and risk for PTSD. In conclusion, low HDL-C and high TG may be risk factors for PTSD. Determining lipid profiles might help identify those at risk for PTSD after experiencing trauma.

Mental health service requirements in a Japanese medical centre emergency department.

BACKGROUND: A significant number of emergency department (ED) patients in Japan may be affected by mental health problems leading to attempted suicide. This retrospective descriptive study aimed to explore mental health service needs in a Japanese medical centre ED. METHODS: Data on all inpatients were collected within 24 h of admission to the ED of a medical centre in Tokyo from 1st February 2004 to the 31st of January 2005. RESULTS: A total of 14.4% (95% CI 13.0 to 16.0) of ED visits required psychiatric services and 23.4% (95% CI 21.7 to 25.3) of inpatients had experienced psychologically traumatic events. CONCLUSIONS: Approximately 38% (95% CI 35.8 to 39.9) of patients presenting to an ED could be affected by mental health problems.

Hyperbaric oxygenation therapy enhances the protective effect of moderate hypothermia against forebrain ischemia in the gerbil hippocampus.

Moderate hypothermia may have a beneficial effect on the neurological outcome. However, ischemic deterioration such as brain swelling during rewarming has been reported as a notable complication after successful therapeutic cerebral hypothermia. In this study, we investigated the effects of hyperbaric oxygenation during rewarming. Forebrain ischemia was produced in 24 gerbils and sham ischemia in 8 animals. Then ischemia-treated animals were divided into 3 groups, whole-body moderate hypothermia (31 degrees C for 60 min) and hyperbaric oxygenation (HBO2) (2- atmosphere absolute for 60 min using 100% oxygen) during rewarming group (n = 8), moderate hypothermia without HBO2 group (n = 8), and sham treatment without hypothermia and without HBO2 group (n = 8). Both the hypothermia group (77.9 +/- 48.1 neurons per mm, mean +/- SD) and hypothermia + HBO2 group (127.6 +/- 29.7 neurons per mm,) showed significant preservation of CA1 pyramidal neurons in the hippocampus compared to that in the sham treatment group (6.4 +/- 2.7) (p < 0.01). Furthermore, the hypothermia + HBO2 group showed significantly greater preservation of CA1 pyramidal neurons than the hypothermia group (p < 0.05). These results suggest that HBO2 during rewarming preserves the protective effect of hypothermia against ischemic neuronal damage.