Chronic in Vivo Testing of a Fully Implantable Intracranial Pressure Sensor

1974 ◽  
Vol 21 (1) ◽  
pp. 702-706 ◽  
Author(s):  
Glenn A. Meyer ◽  
Warren C. Lyon ◽  
Thomas S. Bustard
Keyword(s):  
Intracranial Pressure ◽  
Pressure Sensor ◽  
In Vivo Testing

Clinical Evaluation of Intraparenchymal Spiegelberg Pressure Sensor

Neurosurgery ◽  
2003 ◽  
Vol 52 (6) ◽  
pp. 1455-1459 ◽  
Author(s):  
Josef-Michael Lang ◽  
Jürgen Beck ◽  
Michael Zimmermann ◽  
Volker Seifert ◽  
Andreas Raabe
Keyword(s):  
Intracranial Pressure ◽  
Pressure Sensor ◽  
Pressure Measurement ◽  
Clinical Investigation ◽  
Low Cost ◽  
Absolute Difference ◽  
Intraventricular Pressure ◽  
Technical Problems ◽  
Computed Tomographic

Abstract OBJECTIVE The Spiegelberg 3-PN intraparenchymal pressure sensor was clinically evaluated. DESCRIPTION OF INSTRUMENTATION The Spiegelberg intraparenchymal pressure sensor is a low-cost device that uniquely performs regular automatic zeroing in situ throughout the measurement period. OPERATIVE TECHNIQUE The Spiegelberg sensor was inserted in 87 patients who required intracranial pressure monitoring as part of their routine management. Complications were assessed by postoperative computed tomographic scanning and clinical investigation. The automated zeroing procedure was assessed after implantation of the sensor and during long-term measurement. In five patients, the “gold standard” of intraventricular pressure was measured simultaneously and compared with the intraparenchymal or subdural Spiegelberg 3-PN pressure. EXPERIENCE AND RESULTS No complications associated with the Spiegelberg sensor were observed. The duration of monitoring ranged from 3 to 28 days (mean, 10 d). In 3 patients, technical problems occurred, and in 84 patients, the pressure measurement was successful, including the automatic zeroing procedures performed by the monitor after insertion and hourly thereafter. The absolute difference between the Spiegelberg reading and the intraventricular pressure was less than ±3 mm Hg in 99.6% and less than ±2 mm Hg in 91.3% of readings. An Altman-Bland bias plot revealed good agreement between the two methods, with an average bias of 0.5 mm Hg, but revealed a significant trend toward 10% lower Spiegelberg readings with increasing intracranial pressure of >25 mm Hg. There was no difference between intraparenchymal and subdural locations. CONCLUSION The Spiegelberg 3-PN sensor was reliable and simple to use. It can be recommended for routine intraparenchymal and subdural pressure measurement at a considerably lower price compared with other tip transducers and has the unique advantage of automated zeroing in vivo.

Synthesis, Properties, and in vivo Testing of Biogenic Ferrihydrite Nanoparticles

2020 ◽  
Vol 84 (11) ◽  
pp. 1366-1369
Author(s):  
S. V. Stolyar ◽  
V. P. Ladygina ◽  
A. V. Boldyreva ◽  
O. A. Kolenchukova ◽  
A. M. Vorotynov ◽  
...  
Keyword(s):  
Synthesis Properties ◽  
In Vivo Testing

Aspiration Revisited: Prospective Evaluation of a Physiologically Pressurized Model With Animal Correlation and Broader Applicability to Filler Complications

2021 ◽  
Author(s):  
Hyoung-Jin Moon ◽  
Won Lee ◽  
Ji-Soo Kim ◽  
Eun-Jung Yang ◽  
Hema Sundaram
Keyword(s):  
Normal Saline ◽  
False Negative ◽  
Vascular Complications ◽  
Filler Injection ◽  
Negative Results ◽  
Needle Position ◽  
False Negative Results ◽  
In Vivo Testing

Abstract Background Aspiration testing before filler injection is controversial. Some believe that aspiration can help prevent inadvertent intravascular injection, while others cite false-negative results and question its value given that the needle position always changes somewhat during injection procedures. Objectives To test the relation of false-negative results to the viscosity of the material within the needle lumen and determine whether a less viscous material within the needle lumen could decrease the incidence of false-negative results. Methods In vitro aspiration tests were performed using 30-G and 27-G needle gauges, two cross-linked hyaluronic acid fillers, normal saline bags pressurized at 140 and 10 mmHg to mimic human arterial and venous pressures, and three needle lumen conditions (normal saline, air, and filler). Testing was repeated three times under each study condition (72 tests in total). For in vivo correlation, aspiration tests were performed on femoral arteries and central auricular veins in three rabbits (4–5 aspirations per site, 48 tests in total). Results In vitro and in vivo testing using 30-G needles containing filler both showed false-negative results on aspiration testing. In vitro and in vivo testing using needles containing saline or air showed positive findings. Conclusions False-negative results from aspiration testing may be reduced by pre-filling the needle lumen with saline rather than a filler. The pressurized system may help overcome challenges of animal models with intravascular pressures significantly different from those of humans. The adaptability of this system to mimic various vessel pressures may facilitate physiologically relevant studies of vascular complications.

scholarly journals Effective decellularisation of human saphenous veins for biocompatible arterial tissue engineering applications: Bench optimisation and feasibility in vivo testing

2021 ◽  
Vol 12 ◽  
pp. 204173142098752
Author(s):  
Nadiah S Sulaiman ◽  
Andrew R Bond ◽  
Vito D Bruno ◽  
John Joseph ◽  
Jason L Johnson ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Vascular Tissue ◽  
Sodium Dodecyl ◽  
Host Cells ◽  
Replacement Model ◽  
In Vivo Testing ◽  
Vascular Scaffolds

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.

scholarly journals In vivo testing of the low-flow CO2 removal application of a compact, platform respiratory device

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Alexandra G. May ◽  
Ryan A. Orizondo ◽  
Brian J. Frankowski ◽  
Sang-Ho Ye ◽  
Ergin Kocyildirim ◽  
...  
Keyword(s):  
Low Flow ◽  
Co2 Removal ◽  
In Vivo Testing

scholarly journals Whither Magnetic Hyperthermia? A Tentative Roadmap

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 706
Author(s):  
Irene Rubia-Rodríguez ◽  
Antonio Santana-Otero ◽  
Simo Spassov ◽  
Etelka Tombácz ◽  
Christer Johansson ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Nanoparticle Synthesis ◽  
Careful Analysis ◽  
Magnetic Hyperthermia ◽  
Lessons Learned ◽  
In Vivo Testing ◽  
Evolution Of Science ◽  
Made In ◽  
Critical Aspects

The scientific community has made great efforts in advancing magnetic hyperthermia for the last two decades after going through a sizeable research lapse from its establishment. All the progress made in various topics ranging from nanoparticle synthesis to biocompatibilization and in vivo testing have been seeking to push the forefront towards some new clinical trials. As many, they did not go at the expected pace. Today, fruitful international cooperation and the wisdom gain after a careful analysis of the lessons learned from seminal clinical trials allow us to have a future with better guarantees for a more definitive takeoff of this genuine nanotherapy against cancer. Deliberately giving prominence to a number of critical aspects, this opinion review offers a blend of state-of-the-art hints and glimpses into the future of the therapy, considering the expected evolution of science and technology behind magnetic hyperthermia.

scholarly journals The identification of novel immunogenic antigens as potential Shigella vaccine components

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruklanthi de Alwis ◽  
Li Liang ◽  
Omid Taghavian ◽  
Emma Werner ◽  
Hao Chung The ◽  
...  
Keyword(s):  
Core Genome ◽  
Genomic Analysis ◽  
Carrier Proteins ◽  
Vaccine Candidates ◽  
Vaccine Antigens ◽  
Bactericidal Antibody ◽  
In Vivo Testing ◽  
Species Specific ◽  
Selection Of

Abstract Background Shigella is a major diarrheal pathogen for which there is presently no vaccine. Whole genome sequencing provides the ability to predict and derive novel antigens for use as vaccines. Here, we aimed to identify novel immunogenic Shigella antigens that could serve as Shigella vaccine candidates, either alone, or when conjugated to Shigella O-antigen. Methods Using a reverse vaccinology approach, where genomic analysis informed the Shigella immunome via an antigen microarray, we aimed to identify novel immunogenic Shigella antigens. A core genome analysis of Shigella species, pathogenic and non-pathogenic Escherichia coli, led to the selection of 234 predicted immunogenic Shigella antigens. These antigens were expressed and probed with acute and convalescent serum from microbiologically confirmed Shigella infections. Results Several Shigella antigens displayed IgG and IgA seroconversion, with no difference in sero-reactivity across by sex or age. IgG sero-reactivity to key Shigella antigens was observed at birth, indicating transplacental antibody transfer. Six antigens (FepA, EmrK, FhuA, MdtA, NlpB, and CjrA) were identified in in vivo testing as capable of producing binding IgG and complement-mediated bactericidal antibody. Conclusions These findings provide six novel immunogenic Shigella proteins that could serve as candidate vaccine antigens, species-specific carrier proteins, or targeted adjuvants.

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