〈161〉 Medical Devices—Bacterial Endotoxin and Pyrogen Tests

2021 ◽  
Keyword(s):  
Medical Devices ◽  
Bacterial Endotoxin

scholarly journals Bacterial endotoxin detection in hyaluronic acid-based medical devices

2016 ◽  
Vol 105 (5) ◽  
pp. 1210-1215 ◽  
Author(s):  
Larissa F. Baeva ◽  
Srilekha Sarkar Das ◽  
Victoria M. Hitchins
Keyword(s):  
Hyaluronic Acid ◽  
Medical Devices ◽  
Bacterial Endotoxin

Measurement Uncertainty of Chromogenic LAL Assays: Reaction Time and Proportion of Endotoxin and LAL Reagent Affect Release of p-Nitroaniline

2015 ◽  
Vol 98 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Celina Silva Ostronoff ◽  
Felipe Rebello Lourenço
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Measurement Uncertainty ◽  
Medical Devices ◽  
Bacterial Endotoxin ◽  
Limulus Amebocyte Lysate ◽  
End Point ◽  
Bacterial Endotoxins ◽  
Endotoxin Content ◽  
Detection And Quantification

Abstract Limulus Amebocyte Lysate (LAL) assays are widely used for detection and quantification of bacterial endotoxins in pharmaceuticals and medical devices. However, there are only a few studies on the measurement uncertainty of LAL assays. The aim of this work was to identify and quantify the main sources of measurement uncertainty for end point and kinetic-chromogenic LAL assays. Response surface methodology was used to study how the release of p-nitroaniline (pNA)is affected by reaction time and proportion of endotoxin and LAL reagent in end point and kinetic-chromogenic LAL assays, respectively. Increased release ofpNA was observed when reaction time was increased. In addition, if different volumes of sample (or endotoxin standard) and LAL reagent are used, the pNA release rate will be affected. These results may be dueto the increased interaction between the bacterial endotoxin and LAL-activated enzyme. Final measurementuncertainties (95% confidence interval) were 90–120% and 90–127% of bacterial endotoxin content for end point and kinetic-chromogenic assays, respectively. These values are reasonable for the scope of the method and allow the application of thesemeasurement uncertainties in routine analysis of pharmaceuticals and medical devices.

Ultrastructural changes in murine lymphoma cells exposed to ultraviolet-A radiation

1991 ◽  
Vol 49 ◽  
pp. 104-105
Author(s):  
Delma P. Thomas ◽  
Dianne E. Godar
Keyword(s):  
Medical Devices ◽  
Blood Cells ◽  
White Blood Cells ◽  
Consumer Products ◽  
Ultrastructural Changes ◽  
Ultraviolet A ◽  
Uv Spectrum ◽  
Lymphoma Cells ◽  
Murine Lymphoma ◽  
Transmission Electron

Ultraviolet radiation (UVR) from all three waveband regions of the UV spectrum, UVA (320-400 nm), UVB (290-320 nm), and UVC (200-290 nm), can be emitted by some medical devices and consumer products. Sunlamps can expose the blood to a considerable amount of UVR, particularly UVA and/or UVB. The percent transmission of each waveband through the epidermis to the dermis, which contains blood, increases in the order of increasing wavelength: UVC (10%) < UVB (20%) < UVA (30%). To investigate the effects of UVR on white blood cells, we chose transmission electron microscopy to examine the ultrastructure changes in L5178Y-R murine lymphoma cells.

Bacterial biofilm behavior in water-supply lines of dental units

1992 ◽  
Vol 50 (1) ◽  
pp. 882-883
Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams
Keyword(s):  
Water Supply ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

Patients with chronic diseases: tomorrow, all sentinels?

2020 ◽  
Vol 12 (1) ◽  
pp. 10502
Author(s):  
Jean-David Cohen ◽  
Cyril Crozet ◽  
Jean-François d’Ivernois ◽  
Rémi Gagnayre
Keyword(s):  
Chronic Diseases ◽  
Experimental Research ◽  
Medical Devices ◽  
Clinical Experiences ◽  
Very Old ◽  
Quasi Experimental ◽  
External Measure

Very old studies and clinical experiences of physicians already signal the ability of some patients to feel subclinical signs. These patients are called sentinel patients because they can anticipate crisis very early and therefore intervene quickly to prevent them. Studies have shown that these patients develop these skills from their own experience, in steps which are similar to quasi-experimental research. They test and adjust their competence all the more easily as they have an objective external measure available. This faculty of patients suggests the possibility of using medical devices as a means of learning for patients to tutor themselves in support of this singular skill.

Hemoglobin Enhances the Binding of Bacterial Endotoxin to Human Endothelial Cells

1996 ◽  
Vol 76 (02) ◽  
pp. 258-262 ◽  
Author(s):  
Robert I Roth
Keyword(s):  
Endothelial Cells ◽  
Binding Protein ◽  
Bacterial Endotoxin ◽  
Dependent Manner ◽  
Serum Free Medium ◽  
Free Medium ◽  
Human Endothelial Cells ◽  
Serum Factors ◽  
Serum Free ◽  
Lps Binding

SummaryHuman endothelial cells, when incubated with bacterial endotoxin (lipopolysaccharide, LPS), modify their surface in association with prominent production of procoagulant tissue factor (TF) activity. This deleterious biological effect of LPS has been shown previously to be enhanced approximately 10-fold by the presence of hemoglobin (Hb), a recently recognized LPS binding protein that causes disaggregation of LPS and increases the biological activity of LPS in a number of in vitro assays. The present study was performed to test the hypothesis that Hb enhances the LPS-induced procoagulant activity of human umbilical vein endothelial cells (HUVEC) by increasing LPS binding to the cells. The binding of 3H-LPS to HUVEC was determined in the absence or presence of Hb or two other known LPS-binding proteins, human serum albumin (HSA) and IgG. LPS binding was substantially increased in the presence of Hb, in a Hb concentration-dependent manner, but was not increased by HSA or IgG. Hb enhancement of LPS binding was observed in serum-free medium, indicating that there was no additional requirement for any of the serum factors known to participate in the interaction of LPS with cells (e.g., lipopolysaccharide (LPS)-binding protein (LBP) and soluble CD14 (sCD14)). Hb enhancement of LPS binding also was observed in the more physiologic condition of 100% plasma. LPS-induced TF activity was stimulated by Hb, but not by HSA or IgG. In serum-free medium, TF activity was not stimulated under any of the conditions tested. Ultrafiltration of LPS was dramatically increased after incubation with Hb but not with HSA or IgG, suggesting that LPS disaggregation by Hb was responsible for the enhanced binding of LPS to HUVEC and the subsequent stimulation of TF activity.

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