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Biomedicine & Pharmacotherapy =... Nov 2022Microwave is commonly used in the life, manufacturing and military fields, which may induce body injuries. Brain is the major target organ of microwave radiation and...
Microwave is commonly used in the life, manufacturing and military fields, which may induce body injuries. Brain is the major target organ of microwave radiation and microwave-induced brain injury (MIBI) can lead to insomnia, dreaminess, and a decline in learning and memory. However, there is no clinical medications are available currently. Calcium channel blockers may protect the brain tissue from microwave but most of them cannot enter the brain. Here, we selected a calcium channel blocker-cinnarizine to prepare its dissolving microneedles (MNs) for the therapy of MIBI. The cinnarizine MNs was composed of polyvinyl pyrrolidone (PVP) K90 as the tip, the photopolymerized PVP as the base and the drug, which owned high mechanical strength, leading to easily piecing the skin on the neck and high drug release in vivo. The cinnarizine MNs markedly improved the recovery of spatial memory and spontaneous exploratory behavior of the rats after microwave radiation by inhibiting the expression of calcineurin and calpain-1. The dissolving MN technique is a promising method to improve drugs into the body and perform the anti-microwave radiation action.
Topics: Rats; Animals; Administration, Cutaneous; Cinnarizine; Calcium Channel Blockers; Needles; Drug Delivery Systems; Calcineurin; Calpain; Polyvinyls; Povidone; Brain Injuries
PubMed: 36271560
DOI: 10.1016/j.biopha.2022.113779 -
Radiology. Imaging Cancer Jul 2022
Topics: Embolization, Therapeutic; Polyvinyls; Vascular Surgical Procedures
PubMed: 35838533
DOI: 10.1148/rycan.229012 -
The Journal of Contemporary Dental... Dec 2023The aim of the current study was to evaluate the dimensional accuracy of three various interocclusal recording materials.
AIM
The aim of the current study was to evaluate the dimensional accuracy of three various interocclusal recording materials.
MATERIALS AND METHODS
A total of 90 disc-shaped samples were prepared using polyether paste, wax, and polyvinyl siloxane material with the support of stainless steel die. For the purposes of this investigation, three frequently utilized interocclusal recording materials were chosen, and 30 samples from each material were prepared. Group I: Bite registration using polyether paste; Group II: Bite registration using wax; Group III: Bite registration using polyvinyl siloxane material. No samples were exposed to direct sunlight during storage and were kept at room temperature. Using a 10x universal measuring microscope, each sample disc was examined for the presence of horizontal and vertical lines inscripted in the die. For each of the samples, readings were taken at different time periods of 24, 48, and 72 hours.
RESULTS
After 24 hours, the less dimensional changes were found in polyether paste group (0.11 ± 0.07) followed by polyvinyl siloxane material group (0.19 ± 0.04) and wax group (0.25 ± 0.12). After 48 hours, the less dimensional changes were found in polyether paste group (0.34 ± 0.02) followed by polyvinyl siloxane material group (0.42 ± 0.01) and wax group (0.94 ± 0.12). After 72 hours, the least dimensional changes were found in polyether paste group (0.46 ± 0.14) followed by polyvinyl siloxane material group (0.92 ± 0.03) and wax group (1.14 ± 0.09).
CONCLUSION
The present study concluded that both the material and time factors had an impact on dimensional stability. The most dimensionally stable group was the polyether paste group, which was followed by the polyvinyl siloxane and wax material groups.
CLINICAL SIGNIFICANCE
Interocclusal recording material records the occlusal connection between real or artificial teeth for occlusal rehabilitation planning and for creating removable and fixed dentures. The creation of a clinically acceptable prosthesis is dependent upon the accuracy of the patient's diagnostic or working casts and the interocclusal record. How to cite this article: Sonkesriya S, Subramanian D, Saha P, . Assessment of Dimensional Accuracy of Three Different Types of Interocclusal Recording Materials. J Contemp Dent Pract 2023;24(12):936-939.
Topics: Humans; Dental Impression Materials; Jaw Relation Record; Siloxanes; Polyvinyls
PubMed: 38317389
DOI: 10.5005/jp-journals-10024-3574 -
Photochemical & Photobiological... Aug 2020Extracorporeal photopheresis (ECP) is an effective immunomodulatory therapy for various diseases. Autologous leukocytes are collected, photoactivated with a...
BACKGROUND
Extracorporeal photopheresis (ECP) is an effective immunomodulatory therapy for various diseases. Autologous leukocytes are collected, photoactivated with a photosensitizer (8-methoxypsoralen, 8-MOP) and UVA light, and subsequently reinfused back to the patient. Leukapheresis and UVA irradiation systems can be integrated into one device (inline) or handled by two separate devices (offline). ECP works via intercalation of 8-MOP into DNA helices and UVA-based interactions to inhibit DNA replication. 8-MOP is known to adhere to plastic materials, which might reduce its availability for intercalation. In the present study we examined the bioavailability of 8-MOP when different plastic materials and solvents are used as matrices.
METHODS
Varying amounts of shredded ethylene vinyl acetate (EVA) and polyvinylchloride (PVC) from the MacoGenic irradiation bag (EVA1), UVA PIT irradiation bag (EVA2), UVA PIT recirculation bag (PVC A) and UVA PIT tubing (PVC B) by MacoPharma and PIT Medical Systems, respectively, were incubated with 200 ng mL 8-MOP dissolved in diisopropyl ether (DIPE) plus toluene 90/10 vol%, deionized water or plasma. After 2 h 8-MOP concentrations were determined by GC-MS.
RESULTS
After incubation, 8-MOP concentrations varied depending on the amount and type of plastic (PVC > EVA) and solvent (water > plasma > DIPE/toluene). Absorption to 200 mg EVA1 or EVA2 resulted in 8-MOP concentrations of 57% or 32% in water, 91% or 80% in plasma, and 93% or 92% in DIPE/toluene, while 200 mg PVC A and PVC B yielded recovery rates of 26% and 10% in water, 76% and 75% in plasma, and 55% and 30% in DIPE/toluene, respectively. Remaining 8-MOP differed significantly between container materials (EVA vs. PVC; p < 0.022) but not manufacturers (MacoPharma vs. PIT Medical Systems).
CONCLUSION
Absorption loss of 8-MOP depends on the type of plastic and solvent and is more pronounced with water than with plasma. As the DNA binding effect of 8-MOP is dose-dependent, ECP starting doses should be adjusted to ensure that a sufficient concentration of free bioavailable 8-MOP is present during UV irradiation.
Topics: Ethers; Gas Chromatography-Mass Spectrometry; Humans; Methoxsalen; Photopheresis; Photosensitizing Agents; Polyvinyl Chloride; Polyvinyls; Toluene; Ultraviolet Rays
PubMed: 32638713
DOI: 10.1039/c9pp00378a -
Shokuhin Eiseigaku Zasshi. Journal of... 2023We determined the fifteen types of plasticizers, including four kinds of phthalic acid esters (PAEs) used in 220 polyvinyl chloride (PVC) toys on Japanese market from...
We determined the fifteen types of plasticizers, including four kinds of phthalic acid esters (PAEs) used in 220 polyvinyl chloride (PVC) toys on Japanese market from 2019 to 2020. Three kinds of previously undetected types of PAEs were also detected, but not identified in this study. Di (2-ethylhexyl) terephthalate (DEHTP) was the highest detection rate in 209 soft PVC toys out of 220 toys, with 71.2% for designated toys and 88.9% for not-designated toys, respectively, showing a gradual increase from the previous reports in 2009 and 2014. On the other hand, the usages of o-acetyl tributyl citrate and adipic acid esters decreased, but the six types of PAEs prohibited to use for the designated toys in Japan were not detected in them, the usage of diisobutyl phthalate were increased. In contrast, four types of PAEs were detected in not-designated toys. Among them, the detection ratio of di (2-ethyhexyl) phthalate decreased to about 1/10. The content levels of plasticizers in per each sample were continued to keep low level from the report five years ago. These results showed that the main plasticizer used in PVC toys is DEHTP, and that the usage of other plasticizers was decreased.
Topics: Plasticizers; Polyvinyl Chloride; Esters; Japan
PubMed: 37673604
DOI: 10.3358/shokueishi.64.145 -
ASAIO Journal (American Society For... Jul 2022Tissue-mimicking materials (TMMs) have been investigated and used for decades as imaging phantoms in various medical applications. They are designed and fabricated to...
Tissue-mimicking materials (TMMs) have been investigated and used for decades as imaging phantoms in various medical applications. They are designed and fabricated to replicate certain biological tissue characteristics, a process often dictated by the target application. Moreover, TMMs have been utilized in some medical procedural training requiring the use of imaging modalities. One potential application for TMMs is ultrasound-guided cannulation training. Cannulation is a procedure that requires a level of dexterity to gain vascular access using ultrasound guidance while avoiding complications like vessel laceration and bleeding. However, an ideal phantom for this application is yet to be developed. This work investigates the development and characterization of high-fidelity phantoms for cannulation training. The mechanical (shore hardness, elastic modulus, and needle-interaction forces) and acoustic (B-mode ultrasound scans) properties of candidate materials were quantitatively compared with biological tissue. The evaluated materials included ballistic gel, plasticized polyvinyl chloride (PVC), silicone, gelatin, agar, and polyvinyl alcohol (PVA)- cryogel. Mechanical testing demonstrated that each material could replicate the Shore hardness and elasticity characteristics of different biological tissues (skin, fat, and muscle), with PVA and PVC showing tunability by varying composition or fabrication processes. Shore hardness (OO-range) for PVA ranged between 6.3 ± 1.0 to 59.3 ± 2.6 and PVC from 4.8 ± 0.7 to 14.6 ± 0.8. Ultrasound scans of PVA were the closest to human scans, both qualitatively (based on experts' opinion) and quantitatively (based on pixel intensity measurements). Modified mixtures of PVA are found to best serve as high-fidelity cannulation phantoms. Alternatively, PVC can be used to avoid troublesome fabrication processes of PVA.
Topics: Biological Mimicry; Catheterization; Humans; Phantoms, Imaging; Polyvinyl Alcohol; Polyvinyl Chloride; Ultrasonography; Ultrasonography, Interventional
PubMed: 34799525
DOI: 10.1097/MAT.0000000000001593 -
No Shinkei Geka. Neurological Surgery Mar 2023The diagnosis of dural arteriovenous fistulas(DAVF)has advanced with the development of imaging techniques. The indication for treatment of DAVF is generally based on...
The diagnosis of dural arteriovenous fistulas(DAVF)has advanced with the development of imaging techniques. The indication for treatment of DAVF is generally based on classification according to the venous drainage pattern, which determines whether the presentation is benign or aggressive. In recent years, with the introduction of Onyx, transarterial embolization has been increasingly used, and outcomes have improved, although some conditions are more suitable for transvenous embolization. It is important to select an optimal approach based on location and angioarchitecture. Since DAVF is a rare vascular disease with limited evidence, further validation of clinical results is needed to provide more established treatment guidelines.
Topics: Humans; Polyvinyls; Central Nervous System Vascular Malformations; Embolization, Therapeutic; Vascular Surgical Procedures; Treatment Outcome
PubMed: 37055049
DOI: 10.11477/mf.1436204743 -
Korean Journal of Anesthesiology Aug 2023Direct insertion of a double-lumen tube (DLT) using a flexible fiberoptic bronchoscope (FOB) is an option for DLT intubation. The difficult process of fiberoptic...
BACKGROUND
Direct insertion of a double-lumen tube (DLT) using a flexible fiberoptic bronchoscope (FOB) is an option for DLT intubation. The difficult process of fiberoptic intubation is that the different properties of polyvinyl chloride and silicone DLTs may affect railroading differently. Therefore, we aimed to compare intubation using polyvinyl chloride and silicone DLTs over an FOB.
METHODS
Patients aged 19-75 years who required one-lung ventilation under general anesthesia were enrolled in this study. After induction of anesthesia, the anesthesiologist intubated the DLT using FOB. The primary outcome was the difficulty of railroading over the flexible FOB scaled into five grades (I, II-1, II-2, III, and IV). Additionally, the intubation time and mucosal damage were recorded.
RESULTS
A total of 46 patients participated in this study, 23 each in the silicone and polyvinyl groups. The difficulty of railroading over the FOB was significantly different between the two groups (P < 0.001). In the silicone group, the grades of difficulty in railroading were limited to I and II-1; 20 patients (87%) presented no difficulty in advancing the tube. In contrast, in the polyvinyl group, 13 patients (57%) had scores of II-2 and III. Both the intubation time and mucosal damage were significantly better in the silicone group than in the polyvinyl group.
CONCLUSIONS
Intubation using a silicone DLT over an FOB was easier and faster than that with a polyvinyl chloride DLT with lesser trauma around the glottis.
Topics: Humans; Bronchoscopes; Polyvinyl Chloride; Intubation, Intratracheal; Polyvinyls; Silicones; Anesthesia, General
PubMed: 36577506
DOI: 10.4097/kja.22649 -
AAPS PharmSciTech Jun 2021Phospholipid complexation, despite being a successful, versatile, and burgeoning strategy, stickiness of phospholipids leads to suboptimal dissolution rate of drugs....
Phospholipid complexation, despite being a successful, versatile, and burgeoning strategy, stickiness of phospholipids leads to suboptimal dissolution rate of drugs. This work was undertaken to fabricate simvastatin-phospholipid complex (SIM-PLC)-loaded matrix dispersion (SIM-PLC-MD) using Soluplus® as carrier material, to augment dispersibility and dissolution of SIM-PLC without altering complexation between simvastatin (SIM) and phospholipid. SIM-PLC and SIM-PLC-MD were prepared using solvent evaporation and discontinuous solvent evaporation techniques, respectively. The successful complexation was substantiated by FTIR method. Besides, PXRD and SEM studies disclosed the absence of crystallinity of SIM in both SIM-PLC and SIM-PLC-MD. The TEM analysis monitored the self-assembly of SIM-PLC and SIM-PLC-MD into colloidal structures, which could be correlated with redispersion in GIT fluids upon oral administration. The considerable increase in hydrophilicity of SIM-PLC-MD and SIM-PLC as evident from partition coefficient experiment can further be correlated with their remarkably improved solubility profiles in the following pattern: SIM-PLC-MD˃SIM-PLC˃SIM. Correspondingly, improved dispersibility of SIM-PLC-MD in comparison to SIM-PLC can be accountable for accelerated dissolution rate by 2.53-fold and 1.5-fold in pH 1.2 and 6.8 conditions, respectively. The oral pharmacokinetic evaluation in Sprague Dawley (SD) rats revealed 3.19-fold enhancement in oral bioavailability of SIM through SIM-PLC-MD when compared with plain SIM, whereas 1.83-fold increment was observed in the case of SIM-PLC. Finally, the efficacy experimentation in SD rats revealed that SIM-PLC-MD significantly reduced triglycerides and cholesterol levels in comparison to SIM and SIM-PLC. These outcomes suggest that a matrix dispersion strategy improves oral bioavailability and hypolipidemic activity of SIM.
Topics: Administration, Oral; Animals; Biological Availability; Female; Phospholipids; Polyethylene Glycols; Polyvinyls; Rats; Rats, Sprague-Dawley; Simvastatin; Solubility; Solvents
PubMed: 34159457
DOI: 10.1208/s12249-021-02067-x -
Journal of Chromatographic Science Feb 2022To assess the surface characteristics, composition and release of components of Polyvinyl siloxane (PVS) impression material and explore the use of the material other...
OBJECTIVE
To assess the surface characteristics, composition and release of components of Polyvinyl siloxane (PVS) impression material and explore the use of the material other than for impressions.
METHODS
Forty samples of 0.5-mm thickness and 8-mm diameter PVS discs, with few perforations, were prepared and divided into four groups. Group 1 in methanol was analyzed by GC-MS immediately and on 1st, 7th and 14th day. Group 2 and 3 placed in 10 mL of human saliva and in artificial nasal fluid, respectively, were analyzed by GC-MS at 24 hours. Group 4 was subjected to surface characteristics analysis by placing five PVS discs each in 1 mL of human saliva and 1 mL of artificial nasal fluid, respectively.
RESULTS
On Day 1, Dodecanoic acid, methyl ester, Cyclononasiloxane, octadecamethyl, Cyclodecasiloxane and eicosamethyl (four peaks) were observed in Group 1. At 24 hours, Group 2 had additional compounds of 2-Decene,7-methyl-(Z)-, 2-Undecene,8-methyl-(Z)- and Lauryl acetate. Group 3 showed release of 32 compounds, but their retention time was less. Surface characteristics on Day 14 revealed no noticeable changes.
CONCLUSIONS
The study revealed that there was a lack of any adverse component release from PVS for a period of 2 weeks based on GC-MS analysis.
Topics: Gas Chromatography-Mass Spectrometry; Humans; Polyvinyls; Siloxanes
PubMed: 33987640
DOI: 10.1093/chromsci/bmab054