ABSTRACT
The CRISPR-Cas system provides a versatile RNA-guided approach for a broad range of applications. Thanks to advances in RNA synthetic biology, the engineering of guide RNAs (gRNAs) has enabled the conditional control of the CRISPR-Cas system. However, achieving precise regulation of the CRISPR-Cas system for efficient modulation of internal metabolic processes remains challenging. In this work, we developed a robust dCas9 regulator with engineered conditional gRNAs to enable tight control of endogenous genes. Our conditional gRNAs in Escherichia coli can control gene expression upon specific interaction with trigger RNAs with a dynamic range as high as 130-fold, evaluating up to a three-input logic A OR (B AND C). The conditional gRNA-mediated targeting of endogenous metabolic genes, lacZ, malT and poxB, caused differential regulation of growth in Escherichia coli via metabolic flux control. Further, conditional gRNAs could regulate essential cytoskeleton genes, ftsZ and mreB, to control cell filamentation and division. Finally, three types of two-input logic gates could be applied for the conditional control of ftsZ regulation, resulting in morphological changes. The successful operation and application of conditional gRNAs based on programmable RNA interactions suggests that our system could be compatible with other Cas-effectors and implemented in other host organisms.
Subject(s)
CRISPR-Cas Systems , Escherichia coli Proteins , Escherichia coli , Gene Expression Regulation, Bacterial , RNA, Guide, CRISPR-Cas Systems , Escherichia coli/genetics , Escherichia coli/metabolism , RNA, Guide, CRISPR-Cas Systems/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cytoskeletal Proteins/genetics , Cytoskeletal Proteins/metabolism , LogicABSTRACT
In the era of the COVID-19 pandemic, the significance of point-of-care (POC) diagnostic tools has become increasingly vital, driven by the need for quick and precise virus identification. RNA-based sensors, particularly toehold sensors, have emerged as promising candidates for POC detection systems due to their selectivity and sensitivity. Toehold sensors operate by employing an RNA switch that changes the conformation when it binds to a target RNA molecule, resulting in a detectable signal. This review focuses on the development and deployment of RNA-based sensors for POC viral RNA detection with a particular emphasis on toehold sensors. The benefits and limits of toehold sensors are explored, and obstacles and future directions for improving their performance within POC detection systems are presented. The use of RNA-based sensors as a technology for rapid and sensitive detection of viral RNA holds great potential for effectively managing (dealing/coping) with present and future pandemics in resource-constrained settings.
Subject(s)
Biosensing Techniques , COVID-19 , Humans , Pandemics , COVID-19/diagnosis , RNA, Viral/genetics , Point-of-Care Systems , Biosensing Techniques/methods , COVID-19 TestingABSTRACT
Control of polymer topologies is essential to determine their unique physical properties and potential applications. The polymer topologies can have a critical effect on pigment dispersion owing to their unique architectures; however, studies using polymer topologies on pigment dispersion in aqueous systems are scarce. Thus, this study proposes various topologies of polyether-based waterborne synergists, such as linear, hyperbranched, and branched cyclic structures. Specifically, we applied branched types of polyglycidols (PGs) as a synergist to provide polymer topology-dependent dispersibility for the surface-modification of Red 170 particles through adsorption and steric hindrance. The topology-controlled PG synergists (PGSs) were successfully prepared by post-polymerization modification with phthalimide and benzoyl groups. Particularly, the branched types of PGSs, branched cyclic PGS (bc-PGS), and hyperbranched PGS (hb-PGS) exhibited improved dispersibility through adsorption on top of the pigment, interaction between dispersant (BYK 190) and pigment, and steric effect. Surprisingly, hb-PGS conferred the Red 170 pigment particles with superior storage stability than that of bc-PGS despite their similar structural features. This study suggests the widespread potential application of PGSs as waterborne synergists for various dispersion applications.
ABSTRACT
BACKGROUND: Anastomotic leaks (AL) are a major source of post-esophagectomy morbidity and patients are often initially asymptomatic. Debate exists on timing and utility of imaging to detect AL post-esophagectomy. We sought to evaluate the efficacy and timing of radiographic AL evaluation in esophageal cancer patients post-esophagectomy. METHODS: A retrospective database of esophageal cancer patients who underwent esophagectomy at a single institution from 2004 to 2020 was used to determine the utilization, timing, and sensitivity of radiologic testing for AL post-esophagectomy. RESULTS: Seventy-six patients were identified of which 37 (49%) had a cervical anastomosis. Sixty-four (84%) underwent 71 "asymptomatic radiographic leak tests" (ARLT), 7 of which had 2 different tests, including: 41 fluoroscopic esophagrams (58%), 18 CT-esophagrams (25%), and 12 upper GI studies (17%). Seventeen patients (22%) developed clinical signs of AL (hemodynamic instability, leukocytosis) and underwent "symptomatic radiographic leak tests" (SRLT) with fluoroscopic esophagram (n = 9, 12%), CT-esophagram (n = 7, 9%), or upper GI study (n = 1, 1%). ARLT and SRLT were positive in 2/64 (3%) and 17/17 (100%) patients, respectively, for 19 total ALs (25%). Among the 17 SRLT( +) patients, 1 was also ARLT( +), 13 were initially ARLT( -), and 3 were not evaluated by ARLT. The median postoperative day for ARLT and SRLT was 4.0 (IQR 3.0-5.5) and 9.0 days (IQR 6.0-13.0), respectively, with a statistically significant difference (p < 0.005). The sensitivity and specificity of ARLT for detecting AL were 13.3% and 100.0%, respectively. CONCLUSIONS: Based on the low ARLT sensitivity, routine use of imaging to detect asymptomatic ALs post-esophagectomy may be limited. Symptomatic ALs were often present in a delayed fashion, even after initial negative imaging.
Subject(s)
Anastomotic Leak , Esophageal Neoplasms , Esophagectomy , Anastomosis, Surgical/adverse effects , Anastomotic Leak/diagnostic imaging , Anastomotic Leak/etiology , Asymptomatic Diseases , Diagnostic Tests, Routine , Esophageal Neoplasms/diagnostic imaging , Esophageal Neoplasms/surgery , Esophagectomy/adverse effects , Humans , Postoperative Complications/diagnostic imaging , Postoperative Complications/etiology , Postoperative Complications/surgery , Retrospective Studies , Sensitivity and SpecificityABSTRACT
Synthetic biologists have applied biomolecular engineering approaches toward the goal of novel biological devices and have shown progress in diverse areas of medicine and biotechnology. Especially promising is the application of synthetic biological devices towards a novel class of molecular diagnostics. As an example, a de-novo-designed riboregulator called toehold switch, with its programmability and compatibility with field-deployable devices showed promising in vitro applications for viral RNA detection such as Zika and Corona viruses. However, the in vivo application of high-performance RNA sensors remains challenging due to the secondary structure of long mRNA species. Here, we introduced 'Helper RNAs' that can enhance the functionality of toehold switch sensors by mitigating the effect of secondary structures around a target site. By employing the helper RNAs, previously reported mCherry mRNA sensor showed improved fold-changes in vivo. To further generalize the Helper RNA approaches, we employed automatic design pipeline for toehold sensors that target the essential genes within the pks island, an important target of biomedical research in connection with colorectal cancer. The toehold switch sensors showed fold-changes upon the expression of full-length mRNAs that apparently depended sensitively on the identity of the gene as well as the predicted local structure within the target region of the mRNA. Still, the helper RNAs could improve the performance of toehold switch sensors in many instances, with up to 10-fold improvement over no helper cases. These results suggest that the helper RNA approaches can further assist the design of functional RNA devices in vivo with the aid of the streamlined automatic design software developed here. Further, our solutions for screening and stabilizing single-stranded region of mRNA may find use in other in vivo mRNA-sensing applications such as cas13 crRNA design, transcriptome engineering, and trans-cleaving ribozymes.
ABSTRACT
The microbiome is the metagenome of all microbes that live on and within every individual, and evidence for its role in the pathogenesis of a variety of diseases has been increasing over the past several decades. While there are various causes of sepsis, defined as the abnormal host response to infection, the host microbiome may provide a unifying explanation for discrepancies that are seen in septic patient survival based on age, sex, and other confounding factors. As has been the case for other human diseases, evidence exists for the microbiome to control patient outcomes after sepsis. In this review, associative data for the microbiome and sepsis survival are presented with causative mechanisms that may be at play. Finally, clinical trials to manipulate the microbiome in order to improve patient outcomes after sepsis are presented as well as areas of potential future research in order to aid in the clinical treatment of these patients.
ABSTRACT
This study aimed to investigate the effects of suboccipital muscle inhibition technique (SMIT) on active range of motion (AROM) of the ankle joint, lunge angle (LA), and balance in healthy adults, according to the duration of its application. A total of 80 participants were randomly allocated to the 4-min suboccipital muscle inhibition (SMI) group (SMI_4M, n = 20), 8-min SMI group (n = 20), 4-min sham-SMI (SSMI) group (n = 20), and 8-min SSMI group (n = 20). Accordingly, the SMIT and sham SMIT were applied for 4 min or 8 min in the respective groups. AROM of dorsiflexion and LA were assessed, and a single leg balance test (SLBT) was performed before and after the intervention. AROM (4 min, p < 0.001; 8 min, p < 0.001), LA (4 min, p < 0.001; 8 min, p < 0.001), and SLBT (4 min, p < 0.001; 8 min, p < 0.001) significantly improved after SMI application. Compared with the SSMI group, the SMI group showed a significant increase in AROM (p < 0.001), LA (p < 0.001), and SLBT (p < 0.001). Except for SLBT (p = 0.016), there were no significant interactions between intervention and application duration. The results suggest that the SMIT, at durations of both 4 and 8 min, could be effective tools for improving AROM, LA, and balance.
ABSTRACT
BACKGROUND: The corner pocket (CP) approach for supraclavicular block (SCB) prevents ulnar nerve (UN) sparing due to needle proximity to the lower trunk. Improved ultrasound resolution has suggested that the intertruncal (IT) approach is a suitable alternative method. We compared efficiency of these two approaches on the UN blockade. METHODS: Sixty patients were randomized to undergo SCB using the ultrasound-guided CP or IT approach. For lower trunk blockade, 10 ml of local anesthetic agents (1 : 1 mixture of 0.75% ropivacaine and 1% lidocaine) were injected in the CP (CP approach) or between the lower and middle trunks (IT approach). Additional 15 ml was injected identically to block the middle and upper trunks in both groups. Sensory and motor blockade was evaluated after intervention. RESULTS: Complete sensory blockade (75.9% [22/29] vs. 43.3% [13/30], P = 0.023) and complete motor blockade (82.8% [24/29] vs. 50.0% [15/30], P = 0.017) of the UN at 15 min after SCB were significantly more frequent in the IT than in the CP group. Sensory block onset time of the UN was significantly shorter in the IT compared to the CP group (15.0 [10.0, 15.0] min vs. 20.0 [15.0, 20.0] min, P = 0.012). CONCLUSIONS: The IT approach provided a more rapid onset of UN blockade than the CP approach. These results suggest that the IT approach is a suitable alternative to the CP approach and can provide faster surgical readiness.
Subject(s)
Brachial Plexus Block , Ultrasonography, Interventional , Anesthetics, Local , Humans , Lidocaine , Prospective StudiesABSTRACT
BACKGROUND: Diffuse alveolar hemorrhage (DAH) is a rare, life-threatening condition that can present as a spectrum of nonspecific symptoms, ranging from cough, dyspnea, and hemoptysis to severe hypoxemic respiratory failure. Perioperative DAH is frequently caused by negative pressure pulmonary edema resulting from acute airway obstruction, such as laryngospasm, although hemorrhage itself is rare. CASE PRESENTATION: This case report describes an unexpected hemoptysis following monitored anesthesia care for vertebroplasty. A 68-year-old Asian woman, with a compression fracture of the third lumbar vertebra was admitted for vertebroplasty. There were no noticeable events during the procedure. After the procedure, the patient was transferred to the postanesthesia care unit (PACU), at which sudden hemoptysis occurred. The suspected airway obstruction may have developed during transfer or immediate arrive in PACU. In postoperative chest x-ray, newly formed perihilar consolidation observed in both lung fields. The patients was transferred to a tertiary medical institution for further evaluation. She diagnosed with DAH for hemoptysis, new pulmonary infiltrates on chest x-ray and anemia. The patient received supportive care and discharged without further events. CONCLUSIONS: Short duration of airway obstruction may cause DAH, it should be considered in the differential diagnosis of postoperative hemoptysis of unknown etiology.
Subject(s)
Anesthesia , Lung Diseases , Vertebroplasty , Aged , Female , Hemoptysis/etiology , Hemorrhage/etiology , Humans , Vertebroplasty/adverse effectsABSTRACT
Development of a human-interactive display enabling the simultaneous sensing, visualisation, and memorisation of a magnetic field remains a challenge. Here we report a skin-patchable magneto-interactive electroluminescent display, which is capable of sensing, visualising, and storing magnetic field information, thereby enabling 3D motion tracking. A magnetic field-dependent conductive gate is employed in an alternating current electroluminescent display, which is used to produce non-volatile and rewritable magnetic field-dependent display. By constructing mechanically flexible arrays of magneto-interactive displays, a spin-patchable and pixelated platform is realised. The magnetic field varying along the z-axis enables the 3D motion tracking (monitoring and memorisation) on 2D pixelated display. This 3D motion tracking display is successfully used as a non-destructive surgery-path guiding, wherein a pathway for a surgical robotic arm with a magnetic probe is visualised and recorded on a display patched on the abdominal skin of a rat, thereby helping the robotic arm to find an optimal pathway.
Subject(s)
Electricity , Imaging, Three-Dimensional , Luminescence , Magnetic Fields , Motion , Animals , Electrodes , Male , Rats, Sprague-Dawley , VolatilizationABSTRACT
The encapsulation of lead halide perovskite nanocrystals (PNCs) with an inert protective layer against moisture and the environment is a promising approach to overcome hinderances for their practical use in optoelectronic and biomedical applications. Herein, a facile method for synthesizing highly luminescent and biocompatible CsPbBr3@SiO2 core-shell PNCs with a controlled SiO2 thickness, which are suitable for both cell imaging and drug delivery, is reported. The synthesized CsPbBr3@SiO2 core-shell PNCs exhibit bright green emission at 518 nm upon excitation of 374 nm. Interestingly, a significant increase in the photoluminescence intensity is observed with an increase in the SiO2 shell thickness, which varies with the increasing reaction time. Cytotoxicity results indicate that the CsPbBr3@SiO2 core-shell PNCs are nontoxic, making them suitable for in vitro cell imaging using HeLa cells. Furthermore, doxorubicin physically adsorbed on the surface of CsPbBr3@SiO2 core-shell PNCs is efficiently released in cells when the drug-loaded perovskite nanoprobes are injected in the cells, indicating that these core-shell nanoparticles can be used for drug loading and delivery. The results of this study suggest that the CsPbBr3@SiO2 core-shell PNCs can pave the way for new biomedical applications and processes.
Subject(s)
Cesium/chemistry , Drug Carriers/chemistry , Lead/chemistry , Luminescent Agents/chemistry , Silicon Dioxide/chemistry , Antibiotics, Antineoplastic/administration & dosage , Antibiotics, Antineoplastic/pharmacology , Calcium Compounds/chemistry , Doxorubicin/administration & dosage , Doxorubicin/pharmacology , Drug Delivery Systems , HeLa Cells , Humans , Neoplasms/diagnostic imaging , Neoplasms/drug therapy , Optical Imaging/methods , Oxides/chemistry , Titanium/chemistryABSTRACT
OBJECTIVE: Gastroenteritis causes significant morbidity and mortality in long-term care facility (LTCF) residents, a growing population within the United States. We set out to better understand gastroenteritis outbreaks in LTCF by identifying outbreak and facility characteristics associated with outbreak incidence as well as outbreak duration and size. DESIGN: We conducted a retrospective cross-sectional study on LTCFs in Philadelphia County from 2009 to 2018. Outbreak characteristics and interventions were extracted from Philadelphia Department of Public Health (PDPH) database and quality data on all LTCFs was extracted from Centers for Medicare and Medicaid Services Nursing Home Compare database. RESULTS: We identified 121 gastroenteritis outbreaks in 49 facilities. Numbers of affected patients ranged from 2 to 211 patients (median patient illness rate, 17%). Staff were reported ill in 94 outbreaks (median staff illness rate, 5%). Outbreak facilities were associated with higher occupancy rates (91% vs 88%; P = .033) and total bed numbers (176 vs 122; P = .071) compared to nonoutbreak facilities. Higher rates of staff illness were associated with prolonged outbreaks (13% vs 4%; P < .001) and higher patient illness rates (9% vs 4%; P = .012). Prolonged outbreaks were associated with lower frequency of cohorting for outbreak management (13% vs 41%; P = .046). CONCLUSION: This study is the largest published analysis of gastroenteritis outbreaks in LTCFs. Facility characteristics and staff disease activity were associated with more severe outbreaks. Heightened surveillance for gastrointestinal symptoms among staff and increased use of cohorting might reduce the risk of prolonged gastroenteritis outbreaks in LTCF.
Subject(s)
Disease Outbreaks , Gastroenteritis , Long-Term Care , Aged , Cross-Sectional Studies , Gastroenteritis/epidemiology , Humans , Medicare , Philadelphia , Retrospective Studies , United StatesABSTRACT
Stratification of asthmatic patients based on relevant biomarkers enables the prediction of responsiveness against immune-targeted therapies in patients with asthma. Individualised therapy in patients with eosinophilic asthma has yielded improved clinical outcomes; similar approaches in patients with neutrophilic asthma have yet to be developed. We determined whether colony-stimulating factors (CSFs) in the airway reflect the inflammatory phenotypes of asthma and contribute to disease progression of neutrophilic asthma.We analysed three different mouse models of asthma and assessed cytokine profiles in sputum from human patients with asthma stratified according to inflammatory phenotype. In addition, we evaluated the therapeutic efficacy of various cytokine blockades in a mouse model of neutrophilic asthma.Among the CSFs, airway granulocyte CSF (G-CSF) contributes to airway neutrophilia by promoting neutrophil development in bone marrow and thereby distinguishes neutrophilic inflammation from eosinophilic inflammation in mouse models of asthma. G-CSF is produced by concurrent stimulation of the lung epithelium with interleukin (IL)-17A and tumour necrosis factor (TNF)-α; therefore, dual blockade of upstream stimuli using monoclonal antibodies or genetic deficiency of the cytokines in IL-17A×TNF-α double-knockout mice reduced the serum level of G-CSF, leading to alleviation of neutrophilic inflammation in the airway. In humans, the sputum level of G-CSF can be used to stratify patients with asthma with neutrophil-dominated inflammation.Our results indicated that myelopoiesis-promoting G-CSF and cytokines as the upstream inducing factors are potential diagnostic and therapeutic targets in patients with neutrophilic asthma.
Subject(s)
Asthma , Asthma/drug therapy , Humans , Inflammation , Lung , Neutrophils , SputumABSTRACT
Sortase-mediated ligation (sortagging) is a versatile, powerful strategy for protein modification. Because the sortase reaction reaches equilibrium, a large excess of polyglycine nucleophile is often employed to drive the reaction forward and suppress sortase-mediated side reactions. A flow-based sortagging platform employing immobilized sortaseâ A within a microreactor was developed that permits efficient sortagging at low nucleophile concentrations. The platform was tested with several reaction partners and used to generate a protein bioconjugate inaccessible by solution-phase batch sortagging.