China
Africa
Explore chapters and articles related to this topic
Conjugated Poly/Oligo-Electrolytes for Cancer Diagnosis and Therapy
Published in John R. Reynolds, Barry C. Thompson, Terje A. Skotheim, Conjugated Polymers, 2019
Lingyun Zhou, Guillermo C. Bazan, Shu Wang
A novel and innovative combination of bacteria vector delivery of toxin and PDT was developed with through the use of cationic poly(fluorene-vinylene-benzothiadiazole) (PFVB, Scheme 24.3, structure 25). PE66 toxin-expressing plasmid pET28a-PE66 was installed into the expression vector BL21-PE66. PFVB coated E. coli [BL21-PE66] was obtained by taking advantage of electrostatic and hydrophobic interactions. The loaded toxin PE66 can be released from the capsules by the collaboration of red-emissive PFVB and a membrane disrupting antibiotic polymyxin B (PLB) so to exert their toxic functions on cancer cells and initiate programmed cell apoptosis. Furthermore, tumor cells can uptake PFVB coated BL21-GFP, a green fluorescent protein (GFP) expressive E. coli, to fabricate the bacterial vectors. After endocytosis, cell death was observed under white light with an intensity of 54 J cm–2 (Figure 24.24).154
Water Characteristics
Published in Paul N. Cheremisinoff, Handbook of Water and Wastewater Treatment Technology, 2019
Other methods used to preserve samples do not allow the BOD or bacterial count to be estimated but are useful for determination of chemical and physical parameters. The addition of sulfuric acid keeps the suspended solids (SS) constant for 8 days and the chemical oxygen demand (COD) constant for at least 17 days, whereas the addition of the antibiotic polymyxin B, after heating the sample to 80°C for 1 hr, gave constant COD values for at least 6 months on storage at 22–27°C. Mercuric chloride, added at 3–50 mg/L, depending on the concentration of organic matter in the sample, preserved samples for at least 2 weeks for the determination of pH value, COD, total solids, volatile solids (VS), ammonia, nitrite, nitrate, and organic nitrogen but interfere in the determination of phosphate and phenol. It is undesirable to use mercuric chloride in gas-liquid chromatography methods and in the methods for organic carbon involving catalytic gaseous oxidation. Agents such as chloroform, formalin, thymol, and potassium cyanide are ineffective. The method chosen will depend on the situation, and two or more methods of preservation may have to be used for a single series of samples. Whatever method is chosen, the samples should be stored in the dark in full bottles.
Thin-Layer Chromatography in Bacteriology
Published in Bernard Fried, Joseph Sherma, Practical Thin-Layer Chromatography, 2017
With regard to TLC overlay procedures, the choice of TLC plate is of critical importance. Some plates do not require treatment with the plastic polyisobutylmethacrylate (PIBM) prior to their use in this assay. PIBM has been shown to cause artifacts regarding functional glycolipid receptors of bacterial toxins. Specifically, in the presence of PIBM, verotoxin-1 (VT1) binds globotetraosyl ceramide, which is not a functional receptor for VT1 because its Galα1-4Gal residues are not terminal, and shows reduced binding to globotriaosyl ceramide and P1 glycolipid, which are known functional receptors.25 It appears that PIBM can distort the carbohydrate conformation of glycolipids and alter their receptor properties. For this reason it is highly recommended that plates be used that do not require pretreatment with PIBM. Plastic–backed plates available from Brinkmann Instruments (Westbury, NY) and J.T. Baker Chemical Co. (Phillipsburg, NJ) can be used in this manner. Other factors known to predispose VT1 to artifactually recognize globotetraosyl ceramide include the presence of the antibiotic polymyxin B, which is commonly used in toxin purification protocols and must be removed from toxin preparations.26 Long–term storage of toxin at 4°C can also produce toxin that recognizes globotetraosyl ceramide, probably due to slight denaturation of the toxin structure.
Preparation, characterization and application of curcumin based polymeric bio-composite for efficient removal of endotoxins and bacterial cells from therapeutic preparations
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Pragya Prakash, Hare Ram Singh, Santosh Kumar Jha
LPS removal from blood needs a robust binding force as LPS is already bound to monocytes or lipoproteins [9]. An antibiotic agent Polymyxin B holds healthy bactericidal activity for gram-negative bacteria and also has a strong affinity towards endotoxin. However, intravenous injection of PL-B (Polymyxin-B) is not possible due to its neuro and nephrotoxicity. Alternatives are to utilize this as an absorbent for endotoxin when PL-B is bound to a substrate. Substrates exploited for the purpose are polystyrene and polypropylene conjugated fibers. For the purpose, PL-B is covalently immobilized on the surface of the fibers through the chemical reaction between the primary amino groups of PL-B and an active chlorine atom of the functional groups [10].
Evaluation of the proinflammatory effects of contaminated bathing water
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Anas A. Sattar, Wondwossen Abate, Gyorgy Fejer, Graham Bradley, Simon K. Jackson
Composite samples of marine bathing water were collected on 10 occasions over the summer of 2012 (UK bathing season) at Challaborough beach, Devon, UK (Latitude: 50.287159, Longitude: −3.899052). This beach is a popular bathing, body boarding and surfing beach that is a horseshoe-shaped bay virtually divided by a stream that runs from a valley down into the sea (Sattar, Jackson, and Bradley 2014). In the event of heavy rain, a runoff from the surrounding areas which constitutes a cattle habitat enters the stream and eventually reaches the beach and adversely affects the quality of the bathing water. For the microbiological investigation, samples were collected in 500 ml disposable, sterile, screw-capped wide mouth pots. Water samples for total LPS determination were collected in 50 ml LPS-free Falcone™ tubes (VWR, UK); then, aliquoted into glass tubes and stored at −20°C until assay to inhibit bacterial growth. Part of these water samples was used to investigate the number of FIB and correlated to the total levels of LPS (Sattar, Jackson, and Bradley 2014). Four water samples were selectively chosen in the current study representing different contamination levels based upon bathing water quality classification implemented by the European Union bathing water quality 2006/7/ec (EU 2006). Water sample criteria are presented in Table 1. The LPS content of marine bathing water in the presence or absence of polymyxin B (PMB) was assessed using the Kinetic QCL™ method as described previously (Sattar, Jackson, and Bradley 2014). Polymyxin B (PMB) is an antibiotic that binds to the lipid A moiety of LPS leading to neutralization of LPS when it is subsequently utilized to stimulate immune cells (Cardoso et al. 2007)