1.Bacterial Endotoxin for Intrathoracic Medical Devices Requirement Revisited.
Xiaoqi LIAN ; Xinli SHI ; Lina XING ; Maobo CHENG
Chinese Journal of Medical Instrumentation 2022;46(1):96-98
Bacterial endotoxin is considered as one of the critical risk factors in medical devices, especially implanted devices that directly or indirectly contact with blood circulating system. In that case, endotoxin limits for implanted medical devices is important in determine the safety of medical devices. According to GB/T 14233.2-2005, the requirements of endotoxin index for intrathoracic medical devices is 2.15 EU per device. However, the definition of "intrathoracic medical devices" is vague. Specifically, "for cardiovascular system application" instead of "intrathoracic application" is more reasonable. With the deeper understanding of the risk of endotoxin in medical devices and considering the internationally accepted standards, the limits of endotoxin in medical devices for cardiovascular system application is acceptable at 20 EU per device.
Endotoxins
2.Study on anti-endotoxin of baicalin.
Yong-qing DOU ; Yi XUE ; Hui-zhen CHEN ; Man-lin ZHAO
West China Journal of Stomatology 2007;25(2):169-172
OBJECTIVETo study the anti-endotoxin of different concentration baicalin.
METHODS6.250 microg/mL, 3.125 microLg/mL, 1.562 microg/mL and 0.781 microg/mL baicalin solutions were mixed with I EU/mL endotoxin, respectively. The mixtures were put into water of (37+/-1) degrees C for 15 min, 30 min and 60 min. The degrading effects were determined by using limulus amebocyte lysate test (LAL test).
RESULTS1) The degrading effect of 6.250 microg/mL, 3.125 microg/mL and 1.562 microg/mL baicalin solution on I EU/mL endotoxin was degraded completely in 15 min, 30 min and 60 min, respectively. 2)The degrading effect of 3.125 microg/mL, 1.562 microg/mL and 0.781 microg/mL baicalin solution on 1 EU/mL endotoxin after these mixtures had been incubated for 15 min. Endotoxin values were (0.155 5 +/- 0.002 8) EU/mL, (0.212 1+/-0.004 9) EU/mL, (0.355 9+/-0.013 9) EU/mL, respectively. These differences among them were statistically significant (P<0.01). 3) The degrading effect of 1.562 microg/mL and 0.781 microg/mL baicalin solution on 1 EU/mL endotoxin after these mixtures had been incubated for 30 min. Endotoxin values were (0.1640+/-0.0025) EU/mL and (0.2094+/-0.004 4) EU/mL, respectively. These differences between them were statistically significant (P<0.01).
CONCLUSIONThe action of anti-endotoxin of baicalin is dose-dependent and time-dependent. The results show that baicalin has the stronger anti-endotoxin effect.
Endotoxins ; Flavonoids ; Limulus Test
3.Five simple models for interfering factors test of bacterial endotoxins test.
Yusheng PEI ; Tong CAI ; Hua GAO ; Dejiang TAN ; Yuchen ZHANG ; Guolai ZHANG
Chinese Medical Journal 2014;127(18):3344-3346
Endotoxemia
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diagnosis
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Endotoxins
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analysis
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Humans
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Sepsis
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diagnosis
4.Successful Treatment of Necrotizing Fasciitis and Toxic Shock Syndrome by Hip Amputation and Endotoxin Hemoadsorption
Hiroshi Kamada ; Shigeru Hioki ; Takashi Sato ; Ken Shimizu ; Kuniaki Amano ; Masahiko Takahashi
Journal of Rural Medicine 2008;4(2):91-94
Background: Necrotizing fasciitis is a rare but severe condition associated with high mortality. We encountered a patient with severe and rapidly progressing necrotizing fasciitis. Patient: A 40-year-old male was hit by a tractor and received a wide laceration wound spanning the length of his posterior thigh. Soon after the accident, the wound was washed and debridement was performed. Two days postoperatively, we observed septic changes in the wound and diagnosed this condition as necrotizing fasciitis. Consequently, the patient's leg was amputated at the thigh. The patient, however, developed toxic shock syndrome after the amputation. Endotoxin adsorption using a polymyxin B-immobilized fiber column was performed for 2 days. Finally, a hip joint amputation was performed after 11 days, following which the patient's general condition gradually improved. Discussion: Treatment for necrotizing fasciitis should be initiated promptly. Early debridement is associated with a significant decrease in mortality. In severe conditions, endotoxin and cytokine removal by blood purification is one of the most effective treatments. Although group A streptococci are widely known as "flesh-eating bacteria," we should also consider a wide variety of pathogenic organisms to be the probable cause of severe necrotizing fasciitis. Conclusion: Management of necrotizing fasciitis requires careful investigation as well as an aggressive therapeutic approach, which may include urgent surgical intervention. In addition to surgery, endotoxin adsorption therapy should be considered.
Patients
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Fasciitis
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Endotoxins
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Therapeutic procedure
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Amputation
5.Depyrogenation in key manufacturing processes of Reduning injection.
Miao LI ; Yuling XU ; Juan SONG ; Yongxiang WANG ; Yingzhi PAN ; Zhengzhong WANG ; Wei XIAO ; Tao LIU
China Journal of Chinese Materia Medica 2011;36(6):663-665
OBJECTIVETo investigate the effect of removing bacterial endotoxin in the key processes of Reduning injection.
METHODThe content of bacterial endotoxins was detected by kenitic-turbidimetry and the removal efficacy was studied before and after using 0.8% of activated carbon and ultrafiltration with molecular weight cut-off of 10 x 10(3).
RESULTThe adsorption rate of bacterial endotoxins was 78.7% by using activated carbon, while the removal efficacy of bacterial endotoxins was 99.6% with ultrafiltration membrane at cut-off molecular weight 10 x 10(3).
CONCLUSIONThe key technology can effectively guarantee the safety of Reduning injection.
Adsorption ; Endotoxins ; isolation & purification ; Injections ; Pyrogens ; isolation & purification ; Ultrafiltration
6.Endotoxin deactivation in artificial glass root canals with ultrasonic treatment.
Gui-xiang LIU ; Qing WANG ; Lin-wang SU
West China Journal of Stomatology 2009;27(3):280-282
OBJECTIVETo study the deactivation of the endotoxin in artificial glass root canals with ultrasonic vibration.
METHODS80 artificial glass root canals were randomly divided into 8 groups: Ultrasonic vibration of 5 minutes, 7 minutes, 10 minutes, ultrasonic vibration of 5 minutes together with 3% H2O2 solution, only 3% H2O2 solution, ultrasonic vibration of 5 minutes together with 5.25% NaClO solution, only 5.25% NaClO solution and the control. Standard endotoxin solution was introduced into each root canal. Different time's ultrasonic vibration was applied to different groups. After ultrasonic vibration, the endotoxin activity of each group was tested by kinetic turbidimetric limulus test.
RESULTThere were no significant differences among the groups of different time ultrasonic vibration and the control (P>0.05). There was great statistical difference between each group with root canal rinse solution and the control (P<0.001). The endotoxin activity of the test was significantly lower than the control. There was no significant difference between the groups of only rinse solution and rinse solution together with ultrasonic vibration.
CONCLUSIONUnder the condition of this study, the only ultrasonic vibration can not deactivate the endotoxin of infected root canals and can not intensify the effect of root canal rinse solution.
Dental Pulp Cavity ; Endotoxins ; Hydrogen Peroxide ; Ultrasonics ; Vibration
8.Development of a piezoelectric sensor for detection of low endotoxin concentration.
Xingliang XIONG ; Xiang WANG ; Shaoxi CAI
Journal of Biomedical Engineering 2005;22(5):1040-1044
Endotoxin is an important factor which can lead to endotoxemia and complication. Accurate detection of its concentration is very useful for the diagnosis and treatment of these diseases. A piezoelectric biosensor for detecting endotoxin was developed, which was based on liquid damping effect of quartz crystal resonator. The test results showed that the maximal frequency shift of sensor is linearly dependent on the logarithm value of concentration of endotoxin (0.1 pg/m - 10 ng/ml). The time which d (deltaf)/dt(maax) appeared in frequency shift curve was also linearly dependent on the logarithm value of concentration of endotoxin (0.01 pg/ml - 10 ng/ml). The detection time was shortened and the minimal limit of detection was decreased using the second method. Thus the proposed sensor is much simpler, more precise and has more lower limit of detecting detection of endotoxin when compared with the conventional methods.
Animals
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Biosensing Techniques
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instrumentation
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Endotoxins
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analysis
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Equipment Design
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Quartz
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Rabbits
9.The Effect of Intravitreal Endotoxin Injection on Vitreoretinal Membrane Formation.
Journal of the Korean Ophthalmological Society 1992;33(9):844-852
The course of experimental uveitis and inflammatory membrane proliferation was observed following intravitreal single injection of bacterial endotoxins (Escherichia coli, Salmonella typhimurium, Shigella flexneri). 30 microgram/O.1cc of one endotoxin was injected to 5 pigmented rabbits (total 15 rabbits), then the inflammatory processes of anterior chamber and vitreous cavity were evaluated and the histologic review was also made. Remarkable inflammatory signs were observed in 24-48 hours post-injection, decreased gradually, and disappeared in 1 week post-injection finally. The proliferation of vitreoretinal membrane was observed as early as in 2 weeks post-injection. In histologic examination, there were vitreal thickening, strand-like fibrous structure, and infiltration of spindle shaped cells and monocular cells in 2 weeks post-injection. The membrane, arising from the disc, was composed of the large vascular stalk, fibrous bundles, spindle shaped fibroblast-like cells, and round cells. In this results, the pathogenesis of intraocular membrane proliferation following intraocular inflammation could be understood more precisely.
Anterior Chamber
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Endotoxins
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Inflammation
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Membranes*
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Rabbits
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Salmonella typhimurium
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Shigella
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Uveitis
10.Effects of the 24 N-terminal amino acids of p55PIK on endotoxinstimulated release of inflammatory cytokines by HaCaT cells.
Feng LV ; Wei YOU ; Yang YU ; Jun-bo HU ; Bin ZHANG ; Jing WANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2013;33(4):587-593
This study aimed to examine the effect of the 24 N-terminal amino acids (N24) of p55PIK, a regulatory subunit of phosphatidylinositol 3-kinase (PI3K), on the endotoxin lipopolysaccharide (LPS)-stimulated release of the cytokines (CKs) by HaCaT cells. The fusion protein, trans-acting activator of transcription (TAT)-N24 (an experimental peptide, EP) containing the N24 of PI3K-p55PIK, was constructed, and TAT-N24 fusion peptide was expressed and identified in BL21 E·coli. HaCaT cells (a human keratinocyte cell line) was cultured and stimulated by LPS at 100 ng/mL for 1, 2, 4, 8, 16 or 24 h, or by LPS at 10, 100 ng/mL, 1, 10 or 100 μg/mL of for 4 h. Changes in the protein and mRNA levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) released by HaCaT cells following EP intervention were determined by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Immunofluorescence confocal laser scanning microscopy was utilized to detect the protein expression and translocation of the p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB p65) in HaCaT cells. The expression of the NF-κB inhibitor alpha (IκB-α) protein in LPS-stimulated HaCaT cells after the EP intervention was measured by Western blotting. The results showed that EP treatment increased TNF-α secretion from HaCaT cells. EP at certain concentrations could effectively inhibit the LPS-stimulated release of TNF-α, IL-6 and IL-8 from HaCaT cells. The ELISA assay demonstrated that the concentrations of TNF-α, IL-6 and IL-8 in the supernatants of LPS-stimulated cells were reduced from 208.06±30.18, 86.4±9.78 and 260.59±54.05 pg/mL to 121.78±22.26, 53.18±7.36 and 125.08±35.17 pg/mL, respectively, in the supernatants of cells treated by LPS and EP combined. Real-time PCR also revealed that the expression of the three pro-inflammatory CKs was significantly decreased after EP intervention. Immunofluorescence confocal laser scanning microscopy showed that NF-κB p65 protein was primarily expressed in the cytoplasm of non-stimulated HaCaT cells. After LPS stimulation, NF-κB p65 was translocated into the nucleus, and the nuclear expression of this protein increased. The nuclear NF-κB p65 protein expression was inhibited after the addition of EP. Western blotting showed that IκB-α expression began to decrease 30 min after LPS stimulation and declined to a trough 4 h later. IκB-α expression began to gradually recover 16 h after LPS stimulation but remained at a lower-than-normal level at 24 h. Greater IκB-α expression was found in cells treated with LPS and EP combined than those treated with LPS alone. It was concluded that EP can effectively inhibit the LPS-stimulated expression of TNF-α, IL-6, and IL-8, which involves the inhibition of the hydrolysis of IκB-α and thereby blockage of the nuclear translocation of NF-κB p65.
Amino Acids
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metabolism
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Cell Line
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Cytokines
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metabolism
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Endotoxins
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metabolism
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Humans
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Inflammation
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metabolism
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Phosphatidylinositol 3-Kinases
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metabolism