Largemouth bass virus (LMBV) causes high mortality in largemouth bass, and results in serious economic loses in the aquaculture industry. However, there is no effective treatment to control LMBV ...infection. Aptamers are single-stranded oligonucleotides with high specificity and affinity to various targets, including viruses, viral components, and virus-infected cells. In this study, three novel DNA aptamers (LA38, LB49, and LA13), which specifically targeted LMBV, were identified by selective evolution of ligands by exponential enrichment. These aptamers formed stable stem-loop structures identified by secondary structures and minimum free energy predictions. Moreover, enzyme-linked apta-adsorption assays, dissociation constant (Kd) measurements, and flow cytometry analyses showed that these aptamers specifically bound to LMBV with high affinity at the nanomolar level. Furthermore, these aptamers were nontoxic, and significantly inhibited LMBV infection in vitro and in vivo. The mortality of largemouth bass was reduced approximately 40% after 10 days of infection by LMBV preincubated with LA38 or LB49, compared to that infected with wild or random ssDNA pretreated LMBV. In addition, confocal imaging and flow cytometry analyses indicated that these aptamers only entered cells along with LMBV, suggesting their potential as a delivery system. Presently, this is the first report of specific aptamers targeting iridovirus from freshwater fish. These aptamers have great potential in diagnosis and therapy, and in delivery agents for detecting LMBV infection.
•Three novel aptamers (LA38, LB49, and LA13) targeting Largemouth bass virus (LMBV) were selected by SELEX.•The selected aptamers can specifically target LMBV with high (nanomolar) affinities.•These aptamers were nontoxic, and significantly inhibited LMBV infection in vitro and in vivo.•The selected aptamers can be specifically internalized into cells along with LMBV.
A label-free, cost-effective fiber optic biosensor (FOB) using electrostatic self-assembly (ESA) technology is presented and experimentally demonstrated. The FOB was constructed by sandwiching a ...thin-core single-mode fiber (TCSMF) between two single-mode fibers (SMFs). Firstly, we simulated the refractive index (RI) sensitivity of this fiber structure, and validated it using different concentrations of glycerol solutions. Then the diallyldimethyl ammonium chloride (PDDA) and styrenesulfonate sodium salt (PSS) were employed as polyelectrolyte self-assembled multilayers (PSAMs) deposition for surface functionalization of the fiber. We selected biotin–streptavidin as a bioconjugate pair for testing the effectiveness of the biosensor, and achieved a streptavidin detection limit of 0.02nM. The specificity was further verified by a comparison experiment conducted using bovine serum albumin (BSA) and gelatin. These results demonstrate the feasibility of this sensor for use in biological and chemical applications.
Terrestrial orchid germination, growth and development are closely linked to the establishment and maintenance of a relationship with a mycorrhizal fungus. Mycorrhizal dependency and specificity ...varies considerably between orchid taxa but the degree to which this underpins rarity in orchids is unknown. In the context of examining orchid rarity, large scale in vitro and in situ germination trials complemented by DNA sequencing were used to investigate ecological specialization in the mycorrhizal interaction of the rare terrestrial orchid Caladenia huegelii. Common and widespread sympatric orchid congeners were used for comparative purposes. Germination trials revealed an absolute requirement for mycorrhisation with compatibility barriers to germination limiting C. huegelii to a highly specific and range limited, efficacious mycorrhizal fungus. DNA sequencing confirmed fidelity between orchid and fungus across the distribution range of C. huegelii and at key life history stages within its life cycle. It was also revealed that common congeners could swap or share fungal partners including the fungus associated with the rare orchid but not vice versa. Data from this study provides evidence for orchid rarity as a cause and consequence of high mycorrhizal specialization. This interaction must be taken into account in efforts to mitigate the significant extinction risk for this species from anthropogenically induced habitat change and illustrates the importance of understanding fungal specificity in orchid ecology and conservation.
The aim of this study was to investigate the diagnostic accuracy rates of the patients who underwent an operation for parotid mass, by comparing their fine needle aspiration biopsy (FNAB) cytology ...results with the final pathology. A total of 136 patient files of those who applied to Otorhinolaryngology clinic due to parotid mass and underwent parotidectomy procedure between 2010 and 2020 at a tertiary center were scanned retrospectively. Database on patient age, gender, preoperative FNAB results, and final surgical histopathology results was created. The mean age of the patients was 48.26 ± 17.37 Superficial parotidectomy was performed to 108 (79.4%) and total parotidectomy to 28 (20.6%) of the patients. The sensitivity of FNAB was found as 85.2%, specificity as 96.2%, positive predictive value as 85.2%, negative predictive value as 96.2% and accuracy as 94.0%. It is found that FNAB has the high specificity and high negative predictive value with high diagnostic accuracy on detecting preoperative malignancy in parotid gland. We think that FNAB is a significant, necessary and safe method in the diagnosis of parotid lesions in preoperative sense.
While developing vaccines targeting surface transferrin receptor proteins in Gram-negative pathogens of humans and food production animals, the common features derived from their evolutionary origins ...has provided us with insights on how improvements could be implemented in the various stages of research and vaccine development. These pathogens are adapted to live exclusively on the mucosal surfaces of the upper respiratory or genitourinary tract of their host and rely on their receptors to acquire iron from transferrin for survival, indicating that there likely are common mechanisms for delivering transferrin to the mucosal surfaces that should be explored. The modern-day receptors are derived from those present in bacteria that lived over 320 million years ago. The pathogens represent the most host adapted members of their bacterial lineages and may possess factors that enable them to have strong association with the mucosal epithelial cells, thus likely reside in a different niche than the commensal members of the bacterial lineage. The bacterial pathogens normally lead a commensal lifestyle which presents challenges for development of relevant infection models as most infection models either exclude the early stages of colonization or subsequent disease development, and the immune mechanisms at the mucosal surface that would prevent disease are not evident. Development of infection models emulating natural horizontal disease transmission are also lacking. Our aim is to share our insights from the study of pathogens of humans and food production animals with individuals involved in vaccine development, maintaining health or regulation of products in the human and animal health sectors.
Abstract Background The implementation of institutional protocols in the emergency department (ED) for risk stratification in patients with chest pain has been recommended. Objective To assess the ...sensitivity, specificity and predictive value of an institutional risk stratification protocol for chest pain suggestive of acute coronary syndrome (ACS). Method Cross-sectional study conducted based on the computerized records of patients treated with the use of a chest pain protocol adapted from the Manchester protocol. The level of risk was stratified by applying five colors representing the respective levels. Each color represents a level of severity and a maximum waiting time for receiving medical care. Red and orange were considered to be high priority, while patients with yellow, green or blue indications were considered to represent a low priority. To compare the type of diagnosis and the classification of priority for receiving care, the Pearson's chi-square test was used, considering a significance level of p< 0.05 for all tests. Results The records of 1,074 patients admitted to the cardiology ED were analyzed. Men (54%), with a mean age of 60 ± 15 years, with complaints of chest pain (44%) of moderate intensity (80%) were predominant the study. Of these patients, 19% were classified as high priority, while 81% were considered to represent a low priority. ACS was confirmed in 23% of the patients, with 34% of them being classified as high priority and 66% as low priority. The sensitivity of the risk stratification protocol for chest pain was 33.7% and the specificity was 86.0%, with a positive and negative predictive value of 41.7% and 81.3%, respectively. Conclusion The Institutional risk stratification protocol for chest pain suggestive of ACS presented satisfactory specificity and a low degree of sensitivity. Int J Cardiovasc Sci. 2020; online.ahead print, PP.0-0
Zusammenfassung
Im Kontext des Themenheftes „Die Verortung von Merkmalen der Unterrichtsqualität zwischen Generik und Fachspezifik“ bestehen die Ziele des vorliegenden Beitrags darin, einen ...systematischen Überblick über die in quantitativen, naturwissenschaftsdidaktischen Videostudien angewendeten Kriterien zur Konzeptualisierung und Messung von Unterrichtsqualität zu geben und inhaltliche Beziehungen zu generisch konzeptualisierten und formulierten Kriterien der allgemeinen Unterrichtsforschung herzustellen und zu reflektieren. Im Rahmen eines systematischen Reviews wurden dazu die Kriterien, Operationalisierungen und Beobachtungsitems von 28 Videostudien analysiert, ordnend zusammengefasst und in Beziehung zu einem generisch orientierten Syntheseframework zur Unterrichtsqualität gesetzt, das drei Ebenen unterschiedlicher Auflösungsgrade umfasst. Es wurde ein Kodierverfahren umgesetzt, das wiederum zwischen drei Graden der Übereinstimmung differenziert. Die Objektivität der Kodierungen wurde mit einer Doppelkodierung abgesichert (0,66 < κ < 0,78). Die Ergebnisse zeigen, dass aus naturwissenschaftsdidaktischen Videostudien insgesamt 388 Kriterien extrahiert und in Beziehung zum Syntheseframework gesetzt werden konnten. Insgesamt lässt sich, auf der allgemeinsten Ebene des Frameworks, ein hoher Grad an Überschneidungen zwischen naturwissenschaftsdidaktischen und eher generisch formulierten Perspektiven herstellen. Auf detaillierteren Ebenen zeigt sich, dass zahlreiche Kriterien spezifisch operationalisiert und in Form von „fachspezifischen Perspektivierungen“ dem Framework zugeordnet werden können. Auf dieser Grundlage präsentiert der Beitrag eine Systematisierung generischer und naturwissenschaftsdidaktischer Perspektiven auf Unterrichtsqualität. In der Diskussion wird aufgezeigt, dass diese Systematisierung disziplinenübergreifende Kommunikation ermöglicht und neue Impulse für die weitere naturwissenschaftsdidaktische Unterrichtsqualitätsforschung setzt.
Background: Preterm labor is the second factor lead to neonatal mortality. Recognizing a test for early detection of preterm labor is essential to prevent neonatal complications. This study aimed to ...identify the predictive value of maternal serum levels in diagnosis of preterm labor. Methods: In this case-control study, two groups of women with preterm and term labor were enrolled. Data was collected by interviewing with mother, blood tests and clinical examinations. Data were analyzed by using the statistical t and chi-square tests. To determine the specifity and sensitivity, Receiver Operating Characteristic (ROC) was used. Findings: The maternal mean age was 28.60 ± 5.30 years. The gestational age was associated with serum magnesium level. Based on ROC curve, the best cut-off point for maternal serum magnesium level in the gestational age of 32-36 years was 2.25. At this point, the sensitivity was 34%, specifity 92%, positive predictive value 73%, and negative predictive value was 69%. Conclusion: Our result showed that maternal serum magnesium level can be considered as a predictable test for preterm labor. Regarding the cheapness and available of this test, using it is suggested for the prevention of preterm labor.
PDF
