Serious Clinical Outcomes of COVID-19 Related to Acetaminophen or NSAIDs from a Nationwide Population-Based Cohort Study.

Acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) have been widely prescribed to infected patients; however, the safety of them has not been investigated in patients with serious acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Our objective was to evaluate the association between the previous use of acetaminophen or NSAIDs and the clinical outcomes of SARS-CoV-2 infection. A nationwide population-based cohort study was conducted using the Korean Health Insurance Review and Assessment Database through propensity score matching (PSM). A total of 25,739 patients aged 20 years and older who tested for SARS-CoV-2 were included from 1 January 2015 to 15 May 2020. The primary endpoint was a positive result for a SARS-CoV-2 test, and the secondary endpoint was serious clinical outcomes of SARS-CoV-2 infection, such as conventional oxygen therapy, admission to the intensive care unit, need for invasive ventilation care, or death. Of 1058 patients, after propensity score matching, 176 acetaminophen users and 162 NSAIDs users were diagnosed with coronavirus disease 2019. After PSM, 162 paired data sets were generated, and the clinical outcomes of the acetaminophen group were not significantly different from those of the NSAIDs group. This suggests that acetaminophen and NSAIDs can be used safely to control symptoms in patients suspected of having SARS-CoV-2.

Wide-range robust wireless power transfer using heterogeneously coupled and flippable neutrals in parity-time symmetry.

Recently, stationary wireless power transfer (WPT) has been widely adopted in commercial devices. However, the current WPT configuration is limited in its operational area and susceptible to operating condition changes, impeding its applications for dynamic environments. To overcome the limitations, we propose a WPT system with laterally aligned neutral elements in parity-time (PT) symmetry, which can widen the operational area with the number of neutrals N. Compared to the conventional multiple-input-single-output WPT, the dimension of system complexity is substantially reduced from R × CN to RN+1 because the neutral amplitudes are simply controlled by coupling capacitors. The operational frequency is automatically adjusted to a real eigenvalue of the PT-symmetric system to achieve high voltage gain and efficiency, making the system robust. The performance of the system calculated by the coupled-mode theory was experimentally verified with rigid and flexible types of receivers, confirming its potential in both industrial and biomedical electronics.

Batteryless, Miniaturized Implantable Glucose Sensor Using a Fluorescent Hydrogel.

We propose a biomedical sensor system for continuous monitoring of glucose concentration. Despite recent advances in implantable biomedical devices, mm sized devices have yet to be developed due to the power limitation of the device in a tissue. We here present a mm sized wireless system with backscattered frequency-modulation communication that enables a low-power operation to read the glucose level from a fluorescent hydrogel sensor. The configuration of the reader structure is optimized for an efficient wireless power transfer and data communication, miniaturizing the entire implantable device to 3 × 6 mm 2 size. The operation distance between the reader and the implantable device reaches 2 mm with a transmission power of 33 dBm. We demonstrate that the frequency of backscattered signals changes according to the light intensity of the fluorescent glucose sensor. We envision that the present wireless interface can be applied to other fluorescence-based biosensors to make them highly comfortable, biocompatible, and stable within a body.

Activation of Hypoxia-Inducible Factor-1α Signaling Pathway Has the Protective Effect of Intervertebral Disc Degeneration.

Intervertebral discs (IVDs) have poor nutrient diffusion, because the nucleus pulposus (NP) lacks direct vascular supply and likely generates adenosine triphosphate by anaerobic glycolysis. Regulation of glycolysis is mediated by hypoxia-inducible factor-1α (HIF-1α), a transcription factor that responds to local oxygen tension. Constitutively active HIF-1α (CA HIF-1α) was created by point mutation and determined the protective role of HIF-1α in IVD degeneration. Under fluoroscopy, rat caudal IVD segments were stabbed by a needle puncture, and pcDNA3- HIF-1α wild-type (WT) or pcDNA3-CA HIF-1α was transfected into NP cell lines. The constitutive activity of CA HIF-1α was analyzed using a luciferase assay after cell lysis. Next, IVD tissue samples were retrieved from five patients with degenerative lumbar spinal stenosis at the time of surgery, and NP cells were cultured. NP cells were transfected with CA HIF-1α, and relevant gene expression was measured. HIF-1α protein levels in the nucleus were significantly higher, and transcriptional activity was 10.3-fold higher in NP cells with CA HIF-1α than in those with HIF-1α WT. Gene transfer of CA HIF-1α into NP cells enhanced the expression of Glut-1, Glut-3, aggrecan, type II collagen, and Sox9. Moreover, CA HIF-1α reduced the apoptosis of NP cells induced by the Fas ligand. The HIF-1α and collagen 2 expression levels were notably increased in the NP cells of the CA HIF-1α transfected segments in histology and immunohistochemistry study. Collectively, these results suggest that activation of HIF-1α signaling pathway may play a protective role against IVD degeneration and could be used as a future therapeutic agent.

Newly designed sheaths for gastroduodenal intervention: an experimental study in a phantom and dogs.

OBJECTIVE: To evaluate the usefulness of newly designed sheaths for gastroduodenal intervention in a gastric phantom and dogs. MATERIALS AND METHODS: A regular sheath was made using a polytetrafluoroethylene tube (4 mm in diameter, 90 cm long) with a bent tip (4 cm long, 100 degree angle). For the supported type of sheath, a 5 Fr catheter was attached to a regular sheath to act as a side lumen. To evaluate their supportability, we measured the distance of movement of the sheath's tip within a silicone gastric phantom for three types of sheath, the regular type, supported type, and supported type with a supporting guide wire. The experiments were repeated 30 times, and the results were analyzed using ANOVA with the postHoc test. In addition, an animal experiment was performed in six mongrel dogs (total: 12 sessions) to evaluate the torque and supportability of the sheaths in the stomach, while pushing a guide wire or coil catheter under fluoroscopic guidance. RESULTS: In the guide wire application, the distances of movement of the sheath tip in the three types of sheath, the regular type, supported type, and supported type with supporting guide wire, were 8.40+/-0.51 cm, 6.23+/-0.41 cm, and 4.47 +/-0.32 cm, respectively (p < 0.001). In the coil catheter application, the corresponding values were 7.22+/-0.70 cm, 5.61+/-0.31 cm and 3.91+/-0.59 cm, respectively (p < 0.001). All three types of sheath rotated smoothly and enabled both the wires and catheters to be guided toward the pylorus of the dog in all cases. CONCLUSION: The newly designed sheaths can be useful for gastroduodenal intervention.

Newly designed multifunctional coil catheter for gastrointestinal intervention: feasibility determined by experimental study in dogs.

RATIONALE AND OBJECTIVE: Conventional vascular catheters or sizing catheters are often inconvenient and time-consuming for gastrointestinal procedures. Our purpose was to evaluate the feasibility of a newly designed coil catheter by experimental study in dogs. MATERIALS AND METHODS: Two catheter models were fabricated using a stainless-steel coil covered by heat shrinkable tube. The distal uncovered coil part was not elongated in model A but was elongated in model B. We developed 3 different types in each model: types II and III had 65-cm and 240-cm nitinol wires on the coil surfaces, respectively, but no wire was attached in type I. On the middle covered coil part, multiple holes were made into which to inject contrast medium, and multiple radiopaque markers were attached. In an experimental study using 4 mongrel dogs, we evaluated the ability of the coil catheter to pass over a guide wire to 30 cm distal from the pylorus, the ability of contrast to pass through the injection holes, the visibility of the radiopaque markers, and the ability of the coil catheter to be pushed without a guide wire to 120 cm distal from the pylorus. RESULTS: All catheters were successfully passed to 30 cm distal from the pylorus. Contrast passage through the injection holes and visualization of the radiopaque markers were excellent. To advance to 120 cm distal from the pylorus, the average success rates of models A and B were 100% and 69%, respectively. In particular, model A type II showed the best results in average success rate and average number of trials to achieve success. CONCLUSION: This experimental study demonstrated the feasibility of the newly designed coil catheter for gastrointestinal intervention.

Covered, retrievable, expandable urethral nitinol stent: feasibility study in dogs.

PURPOSE: To evaluate the feasibility of using a retrievable urethral stent and to evaluate whether granulation tissue resolves after stent removal in a canine urethra. MATERIALS AND METHODS: Polyurethane-covered retrievable 0.10-mm-thick (n = 11) or 0.15-mm-thick (n = 10) nitinol wire stents were placed in the urethras of 20 dogs. In one dog, a second stent was placed in the urethra because of complete migration of the first stent into the urinary bladder. The stents were removed with retrieval hook wires 4 weeks (n = 10) and 8 weeks (n = 10) after placement. Fourteen dogs were sacrificed just after stent removal, and the other six dogs were sacrificed 2 weeks after stent removal. Information concerning procedure success, stent migration, and tissue response was obtained. RESULTS: Stent placement was technically successful in all dogs. Follow-up urethrograms showed partial (n = 4) or complete (n = 1) stent migration. Stent removal failed in two dogs due to partial or complete migration. Granulation tissue was observed at both ends of the stent in 17 dogs. Urethrograms and urethral specimens obtained 2 weeks after stent removal showed diminished granulation tissue and decreased thickness of the papillary projections of the epithelium compared with results obtained immediately after stent removal. CONCLUSION: Although some design modifications are necessary to reduce current complications, the polyurethane-covered retrievable nitinol stent seems feasible for use in the urethra. Stent-induced granulation tissue formation improved after stent removal.