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"Hayes, Jennifer"
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Face to face with sharks
Photographer David Doubilet takes you down to the deep, where a variety of this amazing family awaits you, from the famous Great White to his foot-long cousins. Doubilet spends much of his life trying to get close enough to look them in the eye. And now, through Doubilet's remarkable photographs, you can too!
Book
Clinical Performance of Two SARS-CoV-2 Serologic Assays
Abstract
Background
The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a rapid proliferation of serologic assays. However, little is known about their clinical performance. Here, we compared two commercial SARS-CoV-2 IgG assays.
Methods
103 specimens from 48 patients with PCR-confirmed SARS-CoV-2 infections and 153 control specimens were analyzed using SARS-CoV-2 serologic assays by Abbott and EUROIMMUN (EI). Duration from symptom onset was determined by medical record review. Diagnostic sensitivity, specificity, and concordance were calculated.
Results
The Abbott SARS-CoV-2 assay had a diagnostic specificity of 99.4% (95% CI; 96.41–99.98%), and sensitivity of 0.0% (95% CI; 0.00–26.47%) at <3 days post symptom onset, 30.0% (95% CI; 11.89–54.28) at 3–7d, 47.8% (95% CI; 26.82–69.41) at 8–13d and 93.8% (95% CI; 82.80–98.69) at ≥14d. Diagnostic specificity on the EI assay was 94.8% (95% CI; 89.96–97.72) if borderline results were considered positive and 96.7% (95% CI; 92.54–98.93) if borderline results were considered negative. The diagnostic sensitivity was 0.0% (95% CI; 0.00–26.47%) at <3d, 25.0% (95% CI; 8.66–49.10) at 3–7d, 56.5% (95% CI; 34.49–76.81) at 3–7d and 85.4% (95% CI; 72.24–93.93) at ≥14d if borderline results were considered positive. The qualitative concordance between the assays was 0.83 (95% CI; 0.75–0.91).
Conclusion
The Abbott SARS-CoV-2 assay had fewer false positive and false negative results than the EI assay. However, diagnostic sensitivity was poor in both assays during the first 14 days of symptoms.
Journal Article
Face to face with sharks
Photographer David Doubilet takes you down to the deep, where a variety of this amazing family awaits you, from the famous Great White to his foot-long cousins. Doubilet spends much of his life trying to get close enough to look them in the eye. And now, through Doubilet's remarkable photographs, you can too!
Book
Peripheral Nerve Involvement in Friedreich's Ataxia Characterized by Quantitative Magnetic Resonance Neurography
Background Friedreich's ataxia (FRDA) affects both the central and peripheral nervous system. Peripheral nerve involvement manifests predominantly as a progressive sensory neuropathy caused by dorsal root ganglionopathy. An additional direct involvement of peripheral nerves leading to abnormal myelination is increasingly discussed. Here, we characterize lower extremity peripheral nerve involvement in FRDA by quantitative magnetic resonance neurography (MRN). Methods Sixteen genetically confirmed FRDA patients and 16 age‐/sex‐matched controls were prospectively enrolled. Patients underwent neurologic examinations and nerve conduction studies (NCS). Large‐coverage MRN of sciatic and tibial nerves was conducted utilizing dual‐echo turbo‐spin‐echo sequences with spectral fat saturation for T2‐relaxometry, and two gradient‐echo sequences with and without off‐resonance saturation rapid frequency pulses for magnetization transfer contrast imaging. Microstructural and morphometric MRN markers including T2‐relaxation time (T2app), proton spin density (ρ), magnetization transfer ratio (MTR), and cross‐sectional area (CSA) were calculated to characterize nerve lesions. Results Tibial nerve ρ and T2app were markedly decreased in FRDA at the thigh (ρ: 368.4 ± 11.0 a.u.; T2app: 59.5 ± 1.8 ms) and lower leg (ρ: 337.3 ± 12.6 a.u.; T2app: 53.9 ± 1.4 ms) versus controls (thigh, ρ: 458.9 ± 9.5 a.u., p < 0.0001; T2app: 66.3 ± 0.8 ms, p = 0.0019; lower leg, ρ: 449.9 ± 12.1 a.u., p < 0.0001; T2app: 62.4 ± 1.2 ms, p < 0.0001) and correlated well with clinical scores, disease duration, and NCS. MTR and CSA did not differentiate between FRDA and controls. Conclusion Our study results provide a profound characterization of peripheral nerve involvement in FRDA. The identified good correlation between ρ and T2app with clinical symptom scores and NCS suggests that parameters of T2 relaxometry may become relevant biomarkers to monitor disease progression and therapeutic responses in potential future clinical trials.
Journal Article
Highly efficient maternal-fetal Zika virus transmission in pregnant rhesus macaques
Infection with Zika virus (ZIKV) is associated with human congenital fetal anomalies. To model fetal outcomes in nonhuman primates, we administered Asian-lineage ZIKV subcutaneously to four pregnant rhesus macaques. While non-pregnant animals in a previous study contemporary with the current report clear viremia within 10-12 days, maternal viremia was prolonged in 3 of 4 pregnancies. Fetal head growth velocity in the last month of gestation determined by ultrasound assessment of head circumference was decreased in comparison with biparietal diameter and femur length within each fetus, both within normal range. ZIKV RNA was detected in tissues from all four fetuses at term cesarean section. In all pregnancies, neutrophilic infiltration was present at the maternal-fetal interface (decidua, placenta, fetal membranes), in various fetal tissues, and in fetal retina, choroid, and optic nerve (first trimester infection only). Consistent vertical transmission in this primate model may provide a platform to assess risk factors and test therapeutic interventions for interruption of fetal infection. The results may also suggest that maternal-fetal ZIKV transmission in human pregnancy may be more frequent than currently appreciated.
Journal Article
Virtual Versus In-Person Focus Groups: Comparison of Costs, Recruitment, and Participant Logistics
Virtual focus groups-such as online chat and video groups-are increasingly promoted as qualitative research tools. Theoretically, virtual groups offer several advantages, including lower cost, faster recruitment, greater geographic diversity, enrollment of hard-to-reach populations, and reduced participant burden. However, no study has compared virtual and in-person focus groups on these metrics.
To rigorously compare virtual and in-person focus groups on cost, recruitment, and participant logistics. We examined 3 focus group modes and instituted experimental controls to ensure a fair comparison.
We conducted 6 1-hour focus groups in August 2014 using in-person (n=2), live chat (n=2), and video (n=2) modes with individuals who had type 2 diabetes (n=48 enrolled, n=39 completed). In planning groups, we solicited bids from 6 virtual platform vendors and 4 recruitment firms. We then selected 1 platform or facility per mode and a single recruitment firm across all modes. To minimize bias, the recruitment firm employed different recruiters by mode who were blinded to recruitment efforts for other modes. We tracked enrollment during a 2-week period. A single moderator conducted all groups using the same guide, which addressed the use of technology to communicate with health care providers. We conducted the groups at the same times of day on Monday to Wednesday during a single week. At the end of each group, participants completed a short survey.
Virtual focus groups offered minimal cost savings compared with in-person groups (US $2000 per chat group vs US $2576 per in-person group vs US $2,750 per video group). Although virtual groups did not incur travel costs, they often had higher management fees and miscellaneous expenses (eg, participant webcams). Recruitment timing did not differ by mode, but show rates were higher for in-person groups (94% [15/16] in-person vs 81% [13/16] video vs 69% [11/16] chat). Virtual group participants were more geographically diverse (but with significant clustering around major metropolitan areas) and more likely to be non-white, less educated, and less healthy. Internet usage was higher among virtual group participants, yet virtual groups still reached light Internet users. In terms of burden, chat groups were easiest to join and required the least preparation (chat = 13 minutes, video = 40 minutes, in-person = 78 minutes). Virtual group participants joined using laptop or desktop computers, and most virtual participants (82% [9/11] chat vs 62% [8/13] video) reported having no other people in their immediate vicinity.
Virtual focus groups offer potential advantages for participant diversity and reaching less healthy populations. However, virtual groups do not appear to cost less or recruit participants faster than in-person groups. Further research on virtual group data quality and group dynamics is needed to fully understand their advantages and limitations.
Journal Article
