Stomas
Peter Sagar, Andrew G. Hill, Charles H. Knowles, Stefan Post, Willem A. Bemelman, Patricia L. Roberts, Susan Galandiuk, John R.T. Monson, Michael R.B. Keighley, Norman S. Williams in Keighley & Williams’ Surgery of the Anus, Rectum and Colon, 2019
The parastomal mesh repair is based on the similarities seen between incisional hernia and parastomal hernia and was first described in 1977 by Rosin and Bonardi. There are several meshes that can be used, which include absorbable, non-absorbable, partly absorbable and acellular collagen matrix meshes. Given that a parastomal mesh will be in close contact with bowel and effectively passes through a potentially contaminated field, there are obvious concerns regarding the complications of enteric fistulation, adhesions, mesh infection and seroma formation. Substances such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF) are relatively biologically inert when compared to polypropylene. Several large series would indicate acceptable complication rates when placed in the peritoneal cavity.22 Likewise, collagen-based biological mesh has been employed in parastomal hernia repair, as it is considered to be resistant to mesh infection. Using such meshes, the reported rates of mesh infection are as low as 3% on a background of hernia recurrence rates of 20%.103,220
Ultrasound: Future Directions
Armin Ernst, David J. Feller–Kopman in Ultrasound–Guided Procedures and Investigations, 2005
The frequency of transducers is increasing with the use of 30 to 100 MHz probes a realistic proposition early in the 21st century. These transducers rely on single element mechanical devices and are based on the ferroelectric polymer polyvinylidene fluoride (PVDF), which has a high bandwidth (> 100%) but relatively poor sensitivity. Applications in ophthalmology and acoustic microscopy have been developed. US is poised to play an important role in the diagnosis and treatment of ocular diseases ranging from tumors, through retinal and vitreous conditions (seen in diabetes and trauma) to anterior chamber pathologies such as glaucoma. Acoustic microscopy utilizes a number of acoustic tissue characteristics such as attenuation and impedance to produce an image (25). The technique has been applied to dermatological conditions, stomach tumors, and the kidney (26–28). Acoustic microscopy is not yet a widespread diagnostic tool but it should soon be possible to insert an ultra-high frequency microtransducer, via a fine bore needle, into tissue and obtain in situ histology (25).
Prevention of Microbial Contamination during Manufacturing
Philip A. Geis in Cosmetic Microbiology, 2020
With the exception of Polyvinylidene fluoride (PVDF) or Polytetrafluoroethylene (PTFE) and 316L stainless steel, plastic piping is known to be intolerant to the use of heat and ozone as a water system sanitizer (32). PVC piping is also incompatible with most chemical sanitizers. In addition, plasticizers (phthalates) can be leached from PVC piping and are able to serve as a microbial food source for the development and maintenance of a microbial biofilm. Furthermore, PVC piping joints cannot be heat welded but must be joined with couplings that use a solvent to partially dissolve the joints to form a rough weld unlike the smooth welds of stainless steel, PVDF and PTFE. These rough PVC welds are known to be excellent sites for the development of a microbial biofilm. If PVDF and PTFE piping is planned for use to distribute heated water, it needs to be supported and expansion sections will need to be built into the design because it will expand. Furthermore, PVDF and PTFE piping carrying hot water will need to be insulated.
Optimization, characterization and evaluation of ZnO/polyvinylidene fluoride nanocomposites for orthopedic applications: improved antibacterial ability and promoted osteoblast growth
Published in Drug Delivery, 2020
Yanhai Xi, Wenming Pan, Dan Xi, Xue Liu, Jiangmin Yu, Mintao Xue, Ning Xu, Jiankun Wen, Weiheng Wang, Hailong He, Yanyan Liu, Yue He, Chunjing Guo, Daquan Chen, Xiaojian Ye
So far, there exists no natural material with all these properties, but there is promise. Polyvinylidene fluoride (PVDF) possessed good resistance to chemical corrosion, high temperature, oxidation, radiation and it also has piezoelectric, dielectric, thermoelectric and other special properties making it suitable for orthopedic applications. Moreover, the transformation among various PVDF crystal shapes can be achieved (Agarwal et al., 2008; Noriega et al., 2012) so that the PVDF materials with optimal crystal shapes can be prepared according to implant needs (Kumar & Periman, 1993; Lin et al., 2004). PVDF is considered as a potential bone tissue engineering material because of its piezoelectricity (just like bone) and biocompatibility, however, its applications in the body have been limited in that it has no ability to resist bacteria growth or infection (Rim et al., 2013).
Tectoridin alleviates lipopolysaccharide-induced inflammation via inhibiting TLR4-NF-κB/NLRP3 signaling in vivo and in vitro
Published in Immunopharmacology and Immunotoxicology, 2022
Xiaofeng Niu, Huixin Song, Xin Xiao, Jinjin Yu, Jiabao Yu, Yajie Yang, Qiuxia Huang, Lulu Zang, Tengfei Han, Dezhu Zhang, Weifeng Li
Tectoridin was purchased from Chengdu Desite Biotechnology Co., Ltd. (Chengdu, China) with a purity of more than 98%. Dexamethasone (DEX) was purchased from Xi'an Lijun Pharmaceutical Co., Ltd. (Xi'an, China) and used as the positive control. Lipopolysaccharide (LPS, from Escherichia coli 055: B5) was purchased from Sigma (St. Louis, MO, USA). All basic media, the Dulbecco's modified Eagle’s medium (DMEM) and fetal bovine serum (FBS) were products of Gibco (Gibco-BRL, Gaithersburg, MD, USA). The enzyme-linked immunosorbent assay (ELISA) kits for mouse TNF-α, IL-6, IL-18, and IL-1β were obtained from R&D Systems (Minneapolis, MN, USA). NO, Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Urea Nitrogen (BUN), and Creatinine (CRE) detection kits were from Nanjing Jiancheng Institute of Biological Engineering (Nanjing, Jiangsu). Primary antibodies for p-NF-κB p65, NF-κB p65, p-IκBα, IκBα, TLR4, Caspase-1, IL-1β, NLRP3, and β-actin were procured from ABclonal (Boston, MA, USA). Polyvinylidene fluoride (PVDF) membranes were purchased from Pall Gelman Laboratory (Ann Arbor, MI, USA). All other reagents used in the experiment reached or better than analytical grade.
Collagen Deposition and Inflammatory Response Associated with Macroporous Mesh Shrinkage in Incisional Hernia Repair: A Rat Model
Published in Journal of Investigative Surgery, 2022
Peticha Tanprasert, Kanokkan Tepmalai, Bandhuphat Chakrabandhu, Supachai Yodkeeree, Wirawit Piyamongkol, Sirikan Limpakan Yamada
The quantitative analysis comparing materials at different times: the mean is shown, and the error bars represent standard deviation. The statistically significant mean differences among groups are marked with * and **. (a) The IL-6 Levels: At 14 days, the P group had significantly higher IL-6 than the polypropylene with poliglecaprone (PP-PG) group (P =.031). The polyvinylidene fluoride (PVDF) group had significantly higher IL-6 levels than PP-PG (P =.004) and polyester (PE) (P =.019) groups. (b) The collagen type I (Col I) levels: The Col I levels of the polyester (PE) group were lower compared with the primary (P) (P =.002), polypropylene with poliglecaprone (PP-PG) (P =.002), and polyvinylidene fluoride (PVDF) (P =.022) groups at 90 days. (c) The collagen type III (Col III) levels: There was no significant difference between groups at 14, 90, and 180 days. (d) The collagen type IV (Col IV) levels: At 90 days, the polypropylene with poliglecaprone (PP-PG) group’s Col IV levels were higher than primary (P) (P =.012) and PE (P =.008) groups. At 180 days, the polyvinylidene fluoride (PVDF) group was significantly higher than the PP-PG group (P =.047). (e) The Col I/III Ratios: At 90 days, the primary (P) group’s Col I/III ratios were higher than the polyester (PE) group (P =.006).
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