LDH Assay Substrate Solution

2018 ◽  
Vol 2018 (6) ◽  
pp. pdb.rec096867
Keyword(s):  
1998 ◽  
Vol 16 (3) ◽  
pp. 182-188
Author(s):  
Kelly M. Groves ◽  
Stuart L. Warren ◽  
Ted E. Bilderback

Abstract Rooted cuttings of Cotoneaster dammeri Schneid ‘Skogholm’ and seedlings of Rudbeckia fulgida Ait. ‘Goldsturm’ were potted into 3.8 liter (4 qt) containers in a pine bark:sand (8:1 by vol) substrate incorporated with 3.5 g (0.12 oz) N per container provided by one of the following five controlled-release fertilizers (CRFs): Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Two hundred ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) or 1200 ml (1.7 in) of water was applied once daily (single) or in two equal applications with a 2 hr interval between applications (cyclic). Substrate solutions were collected from containers of cotoneaster 15, 32, 45, 60, 74, 90, 105, and 119 days after initiation (DAI). Irrigation efficiency [(water applied − water leached) ÷ water applied] was determined on the same days. Cyclic application improved irrigation efficiency at 800 ml (1.1 in) and 1200 ml (1.7 in) ≈ 27% compared to a single application. Irrigation efficiencies averaged over the season were 95%, 84%, 62%, and 48% for cotoneaster and 100%, 90%, 72%, and 51% for rudbeckia at 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) and 1200 ml (1.7 in), respectively. NH4-N and NO3-N and PO4-P concentrations in substrate solution decreased with increasing irrigation volume regardless of CRF. Substrate NH4-N concentration decreased throughout the season with most CRFs below 5 mg/liter by 90 DAI. CRFs mainly affected substrate NH4-N and NO3-N concentrations when irrigated with 200 ml (0.3 in) or 400 ml (0.6 in). Substrate NH4-N, NO3-N, and PO4-P solution concentrations were similar for all CRFs at irrigation volume of 1200 ml (1.7 in). Osmocote, Scotts, and Woodace maintained relatively constant substrate solution levels of PO4-P through 60 DAI. By 90 DAI, substrate PO4-P levels were similar regardless of irrigation volume or CRF. Substrate PO4-P concentrations were never in the recommended range of 5 to 10 mg/liter when irrigated with 800 ml (1.1 in) or 1200 ml (1.7 in) regardless of CRF. Solution pH remained in the recommended range of 5.0 to 6.0 for all irrigation volumes and CRFs throughout the entire study with the exception of Sustane.


2014 ◽  
Vol 77 (7) ◽  
pp. 1212-1218 ◽  
Author(s):  
BURTON BLAIS ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI ◽  
MARTINE GAUTHIER

A simple immunoenzymatic enterohemorrhagic Escherichia coli (EHEC) colony check (ECC) assay was developed for the presumptive identification of priority EHEC colonies isolated on plating media from enrichment broth cultures of foods. With this approach, lipopolysaccharide extracted from a colony is spotted on the grid of a polymyxin-coated polyester cloth strip, and bound E. coli serogroup O26, O45, O103, O111, O121, O145, and O157 antigens are subsequently detected by sequential reactions with a pool of commercially available peroxidase-conjugated goat antibodies and tetramethylbenzidine substrate solution. Each strip can accommodate up to 15 colonies, and test results are available within 30 min. Assay performance was verified using colonies from a total of 73 target EHEC isolates covering the range of designated priority serogroups (all of which were reactive), 41 nontarget E. coli isolates including several nontarget Shiga toxin–producing E. coli serogroups (all unreactive), and 33 non–E. coli strains (all unreactive except two bacterial strains possessing O-antigenic structures in common with those of the priority EHEC). The ECC assay was reactive with target colonies grown on several types of selective and nonselective plating media designed for their cultivation. These results support the use of the ECC assay for high-throughput screening of colonies isolated on plating media for detecting priority EHEC strains in foods.


2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Martina Koeva ◽  
Alina D. Gutu ◽  
Wesley Hebert ◽  
Jeffrey D. Wager ◽  
Lael M. Yonker ◽  
...  

ABSTRACTBacterial persisters are a quasidormant subpopulation of cells that are tolerant to antibiotic treatment. The combination of the aminoglycoside tobramycin with fumarate as an antibacterial potentiator utilizes an antipersister strategy that is aimed at reducing recurrentPseudomonas aeruginosainfections by enhancing the killing ofP. aeruginosapersisters. Stationary-phase cultures ofP. aeruginosawere used to generate persister cells. A range of tobramycin concentrations was tested with a range of metabolite concentrations to determine the potentiation effect of the metabolite under a variety of conditions, including a range of pH values and in the presence of azithromycin or cystic fibrosis (CF) patient sputum. In addition, 96-well dish biofilm and colony biofilm assays were performed, and the cytotoxicity of the tobramycin-fumarate combination was determined utilizing a lactate dehydrogenase (LDH) assay. Enhanced killing of up to 6 orders of magnitude ofP. aeruginosapersisters over a range of CF isolates, including mucoid and nonmucoid strains, was observed for the tobramycin-fumarate combination compared to killing with tobramycin alone. Furthermore, significant fumarate-mediated potentiation was seen in the presence of azithromycin or CF patient sputum. Fumarate also reduced the cytotoxicity of tobramycin-treatedP. aeruginosato human epithelial airway cells. Finally, in mucoid and nonmucoid CF isolates, complete eradication ofP. aeruginosabiofilm was observed in the colony biofilm assay due to fumarate potentiation. These data suggest that a combination of tobramycin with fumarate as an antibacterial potentiator may be an attractive therapeutic for eliminating recurrentP. aeruginosainfections in CF patients through the eradication of bacterial persisters.


2013 ◽  
Vol 31 (3) ◽  
pp. 356-360 ◽  
Author(s):  
Fernanda Ludwig ◽  
Dirceu M Fernandes ◽  
Poliana RD Mota ◽  
Roberto L Villas Bôas

The quality and the profitability on floriculture are intimately linked to the adequate plant nutrition. In the present research we aimed to evaluate the electrical conductivity (EC) and pH of the substrate solution on four different gerbera cultivars subjected to fertigation, with two nutritive solutions. The experiment was carried out in a greenhouse, from May to July 2006, on the Universidade Estadual Paulista, Botucatu, São Paulo state, Brazil. The experiment was carried out under an experimental design of random blocks, in 4×2 factorial arrangement, with four Gerbera cultivars (Cherry, Golden Yellow, Salmon Rose and Orange) and two nutritive solution concentrations: 0.92 and 1.76 dS m-1 EC) during the vegetative stage, and 1.07 and 2.04 dS m-1 during the reproductive stage (S1 and S2, respectively). The nutrients were applied through fertigation, manually performed every day. The EC and pH values of the substrate solution were evaluated weekly, using the 'pourthru' method. Orange and Cherry cultivars had, respectively, the highest and the lowest electrical conductivity of the substrate solution, and Cherry was the most efficient on the nutrient uptake. The solution S2 showed a trend to accumulate salts in the substrate, but without visual symptoms of plant toxicity, leading to the lowest pH values. The 'pourthru' method was efficient when compared to the 1:2 method and can be adopted for substrate solution analysis in gerbera culture.


2015 ◽  
Vol 38 (4) ◽  
pp. 309-311
Author(s):  
Priyanshu Sharma ◽  
S.P. Chaukiyal ◽  
Meenu Sengar

The combination of different substrate concentrations (0.05M, 0.10M, 0.15M, 0.20M and 0.25M, KNO3) with different pH of phosphate buffer (0.10 M and 0.20 M, KH2PO4 of the pH 7.0, 7.5, 7.6, 7.7, and 7.8) solutions were tried for in-vivo nitrate reductase activity of Adenanthera microsperma leaves. Maximum nitrate reductase activity was observed in the combination of buffer solution (0.20M KH2PO4) having pH 7.7 and substrate solution 0.20 M concentration.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 482 ◽  
Author(s):  
Hao-Hueng Chang ◽  
Yi-Ting Tseng ◽  
Sheng-Wun Huang ◽  
Yi-Fang Kuo ◽  
Chun-Liang Yeh ◽  
...  

A new root canal sealer was developed based on urethane acrylates using polycarbonate polyol (PCPO), a macrodiol prepared in the consumption of carbon dioxide as feedstock. The superior mechanical properties and biostability nature of PCPO-based urethane acrylates were then co-crosslinked with a difunctional monomer of tripropylene glycol diarylate (TPGDA) as sealers for resin matrix. Moreover, nanoscale silicate platelets (NSPs) immobilized with silver nanoparticles (AgNPs) and/or zinc oxide nanoparticles (ZnONPs) were introduced to enhance the antibacterial effect for the sealers. The biocompatibility and the antibacterial effect were investigated by Alamar blue assay and LDH assay. In addition, the antibacterial efficiency was performed by using Enterococcus faecalis (E. faecalis) as microbial response evaluation. These results demonstrate that the PCPO-based urethane acrylates with 50 ppm of both AgNP and ZnONP immobilized on silicate platelets, i.e., Ag/ZnO@NSP, exhibited great potential as an antibacterial composite for the sealer of root canal obturation.


1987 ◽  
Vol 33 (4) ◽  
pp. 498-501 ◽  
Author(s):  
H M Chandler ◽  
S A Fuller ◽  
C H Nakagawa ◽  
P A Nagainis ◽  
J G Hurrell

Abstract A very rapid and sensitive assay for human choriogonadotropin (hCG) has been developed involving two beta-subunit-specific monoclonal antibodies. In the assay the test specimen is passed backward and forward (reflow) through a monoclonal-antibody-coated capillary tube for 1 min, then incubated for 1 min with a second monoclonal antibody conjugated to urease (EC 3.5.1.5). After addition of a urease substrate solution, 10 int. units of hCG per liter can be detected visually within 5 min, which compares very favorably with other currently available hCG assay procedures. Advantages of the reflow/capillary tube assay system and optimization of the test procedure are discussed.


2003 ◽  
Vol 285 (5) ◽  
pp. G870-G879 ◽  
Author(s):  
Maria J. Redlak ◽  
Miranda S. Dennis ◽  
Thomas A. Miller

This study was undertaken to determine whether necrosis or apoptosis was the predominant mechanism responsible for gastric mucosal cellular death using the cell line known as AGS cells. Cells were exposed to various concentrations of deoxycholate (DC; 50–500 μM) for periods ranging from 30 min to 24 h. Lactic dehydrogenase (LDH) activity was used as a marker for necrotic cell death, whereas apoptosis was characterized by 4′,6-diamidino-2 phenylindole staining, DNA gel electrophoresis, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and DNA-histone-associated complex formation. When cells were bathed in Hank's balanced salt solution, DC-induced necrosis was the predominant mechanism of cell death. In contrast, when cells were bathed in Ham's F-12 solution (a more physiologically relevant medium), no evidence of cytotoxicity (by LDH assay) was discernible when cells were exposed to DC (50–300 μM) for periods as long as 8 h; instead, clear evidence of apoptosis was noted that was time and dose dependent. When cells were exposed for 24 h to these DC concentrations, cytotoxicity was also present, indicating necrosis as well. Furthermore, acidification of the ambient environment also evoked a necrotic response when exposed to DC. We demonstrated that apoptosis induced by DC shows early activation of caspase-3 that is dependent on both receptor and mitochondrial pathways. Our results indicate that physiological concentrations of DC (50–300 μM) primarily induce cellular death through an apoptotic process. Only after prolonged exposure to DC or acidification of the bathing solution does necrosis also occur.


Proceedings ◽  
2020 ◽  
Vol 57 (1) ◽  
pp. 41
Author(s):  
Andreea Iosageanu ◽  
Daniela Ilie ◽  
Catalina Sanda ◽  
Oana Craciunescu ◽  
Florin Oancea

The aim of this study was to evaluate the photoprotective effect of fish bone-derived peptides (FBDPs) in a culture of UV-B-irradiated mouse fibroblasts and their anti-inflammatory activity in a model of stimulated human macrophages. The results showed that cell viability of FBDPs-treated and irradiated fibroblasts was higher than that of irradiated cells, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay, after 25 and 60 s of treatment. Moreover, secretion of interleukin 1-beta (IL-1β) was decreased in FBDPs-treated inflamed macrophages, as determined by ELISA assay.


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