Leakage of Endotoxins through the Endotoxin Retentive Filter: An in vitro Study

2022 ◽  
pp. 1-9
Author(s):  
Hiroshi Nozaki ◽  
Yoshihiro Tange ◽  
Yoji Inada ◽  
Takashi Uchino ◽  
Nakanobu Azuma
Keyword(s):  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
In Vitro Study ◽  
Dialysis Fluid ◽  
High Concentration ◽  
Membrane Pores ◽  
Polyether Sulfone ◽  
Repeated Use ◽  
High Concentrations

<b><i>Introduction:</i></b> Ultrapurification of dialysis fluid has enabled highly efficient dialysis treatments. Online hemodiafiltration is one such treatment that uses a purified dialysis fluid as a supplemental fluid. In this method, an endotoxin retentive filter (ETRF) is used in the final step of dialysis fluid purification, with the aim of preventing leakage of endotoxins. Sodium hypochlorite and peracetic acid are used as disinfecting agents for the dialysis fluid pipes containing the ETRF; however, the effects of these agents on ETRF membrane pores have not been fully clarified. <b><i>Methods:</i></b> Water permeability (flux) and endotoxin permeability were assessed in 3 types of ETRFs made with different membrane materials: polyester polymer alloy (PEPA), polyether sulfone (PES), and polysulfone (PS). High-concentration sodium hypochlorite and 2 types of peracetic acid were used as disinfecting agents, and the changes in flux and the endotoxin sieving coefficient (SC) were measured. <b><i>Results:</i></b> After repeated use of high concentrations of sodium hypochlorite and peracetic acid, the PEPA and PES ETRFs did not permit passage of endotoxins, regardless of their flux. However, in the PS ETRF, the flux and endotoxin SC increased with the number of cleaning cycles. No differences were observed according to the concentration of peracetic acid disinfecting agents. <b><i>Conclusion:</i></b> PEPA and PES ETRFs completely prevent endotoxin leakage and can be disinfected at concentrations higher than the conventionally recommended concentration without affecting pore expansion. Even new PS ETRFs have low levels of endotoxin leakage, which increase after disinfection cycles using sodium hypochlorite and peracetic acid.

An In Vitro Analysis of Sodium Hypochlorite Decontamination for the Reuse of Implant Healing Abutments

2020 ◽  
Author(s):  
Ahmad Almehmadi
Keyword(s):  
Sodium Hypochlorite ◽  
Bacterial Culture ◽  
Brain Heart Infusion ◽  
In Vitro Study ◽  
Vitro Study ◽  
Sem Images ◽  
Streptococcus Sanguis ◽  
Implant Dentistry ◽  
Vitro Analysis

Abstract The re-use of healing abutments (HAs) has become common practice in implant dentistry for economic concerns and the aim of this in-vitro study was to assess the effect of sodium hypochlorite (NaOCl) in decontamination of HAs. 122 HAs (Used and sterilized n=107; New n=15) were procured from 3 centers, of which 3 samples were discarded due to perforation in sterilization pouch.  For sterility assessment, the used HAs (n=80) were cultured in Brain Heart Infusion Broth (BHI) and Potato Dextrose Agar (PDA), bacterial isolates were identified in 7 samples. Also, 24 used HAs were stained with Phloxine B, photographed and compared to new HAs (n=5). Scanning electron microscope (SEM) assessed the differences between the two sets of HAs, following which the 7 contaminated HAs along with 24 used HAs from staining experiment (Total=31) were subsequently treated with sodium hypochlorite (NaOCl) and SEM images were observed. About 8.75% of HAs tested positive in bacterial culture; Streptococcus sanguis, Dermabacter hominis, Staphylococcus haemolyticus, and Aspergillus species were isolated. Phloxine B staining was positive for used and sterilized HAs when compared to controls. The SEM images revealed deposits in the used HAs and although treatment with NaOCl eliminated the contamination of cultured HAs, the SEM showed visible debris in the HA thread region. This in-vitro study concluded that SEM images showed debris in used HAs at screw-hole and thread regions even though they tested negative in bacterial culture. The treatment with NaOCl of used HAs showed no bacterial contamination but the debris was observed in SEM images. Future studies on the chemical composition, biological implications, and clinical influence is warranted before considering the reuse of HAs.

Comparative Study to Evaluate the Surface Detail Reproduction of Dental Stone after Immersion in Various Different Disinfectant Solutions, Under Stereomicroscope 10 X Magnification –An In-Vitro Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya
Keyword(s):  
Sodium Hypochlorite ◽  
In Vitro Study ◽  
Control Group ◽  
Immersion Method ◽  
Significant Difference ◽  
Surface Irregularities ◽  
Disinfectant Solution ◽  
Surface Detail ◽  
Group B

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde

The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Vitro Selection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Concentration ◽  
Short Term ◽  
High Concentrations ◽  
Selection Of ◽  
Selection Of Resistance ◽  
Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

scholarly journals Association of beta-cytoplasmic actin with high concentrations of acetylcholine receptor (AChR) in normal and anti-AChR-treated primary rat muscle cultures.

1984 ◽  
Vol 32 (9) ◽  
pp. 973-981 ◽  
Author(s):  
B W Lubit
Keyword(s):  
Acetylcholine Receptor ◽  
Acetylcholine Receptors ◽  
Neuromuscular Junctions ◽  
Morphological Changes ◽  
Muscle Cells ◽  
High Concentration ◽  
Rat Muscle ◽  
Cytoplasmic Actin ◽  
High Concentrations

Previous immunocytochemical studies in which an antibody specific for mammalian cytoplasmic actin was used showed that a high concentration of cytoplasmic actin exists at neuromuscular junctions of rat muscle fibers such that the distribution of actin corresponded exactly to that of the acetylcholine receptors. Although clusters of acetylcholine receptors also are present in noninnervated rat and chick muscle cells grown in vitro, neither the mechanism for the formation and maintenance of these clusters nor the relationship of these clusters to the high density of acetylcholine receptors at the neuromuscular junction in vivo are known. In the present study, a relationship between beta-cytoplasmic actin and acetylcholine receptors in vitro has been demonstrated immunocytochemically using an antibody specific for the beta-form of cytoplasmic actin. Networks of cytoplasmic actin-containing filaments were found in discrete regions of the myotube membrane that also contained high concentrations of acetylcholine receptors; such high concentrations of acetylcholine receptors have been described in regions of membrane-substrate contact. Moreover, when primary rat myotubes were exposed to human myasthenic serum, gross morphological changes, accompanied by an apparent rearrangement of the cytoplasmic actin-containing cytoskeleton, were produced. Although whether the distribution of cytoplasmic actin-containing structures was influenced by the organization of acetylcholine receptor or vice versa cannot be determined from these studies, these findings suggest that in primary rat muscle cells grown in vitro, acetylcholine receptors and beta-cytoplasmic actin-containing structures may be somehow connected.

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