Endotoxinaemia in neonates.
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Endotoxins↗
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Endotoxin reference standard.
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Endotoxins↗
Limulus assay in prediction of septic shock.
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Humans↗
Fungal cell wall beta-1,3-glucans induce clotting and phenoloxidase attachment to foreign surfaces of crayfish hemocyte lysate.
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Animals↗
Endotoxaemia, fever and clinical status in immunosuppressed patients: a preliminary study.
A prospective study was performed in order to find out whether endotoxaemia assays are clinically relevant in neutropenic patients. In a group of 10 immunocompromised patients, serial haematological, bacteriological and clinical investigations were done in parallel with serial plasma endotoxin assays. The chromogenic modification of the Limulus amoebocyte lysate (LAL) assay for endotoxin used in this study had a sensitivity of less than 10 pg endotoxin per ml plasma. It was found that endotoxaemia was associated with Gram-negative bacteraemia but infection with Gram-negative bacteria did not always produce endotoxaemia. Furthermore, infections with Gram-positive bacteria and administration of blood products may lead to raised endotoxin values. Endotoxin assays may be of value for elucidating mechanisms of fever in immunocompromised patients but it seems unlikely that routine assays of endotoxin will help in the clinical management of these patients.
Adult↗
Decreased endotoxin-binding capacity of whole blood in patients with alcoholic liver disease.
BACKGROUND/AIMS: The proinflammatory effects of endotoxemia, which is often observed in alcohol-abusing patients with various degrees of liver disease, may be modulated by changes in the concentration of endotoxin binding factors. Therefore, the plasma endotoxin concentration and the overall endotoxin binding capacity of whole blood were measured in these patients. METHODS: Patients with minor (A1; n=27), more pronounced (A2; n=13), cirrhotic alcoholic liver disease (A3; n=18), and non-alcoholic cirrhosis (NC; n=6), and 15 healthy control persons (HC) were included in the study. Endotoxin plasma levels were determined using a standardized limulus assay. A modified assay was applied to additionally detect tightly bound endotoxin. To measure the endotoxin-binding capacity, aliquots of whole blood were incubated with serial dilutions of endotoxin, supernatants were obtained, and endotoxin retrieval was estimated by addition of limulus lysate, followed by photometric measurement of the maximal reaction velocity (dODmax). Endotoxin binding capacity equals the endotoxin concentration at which dODmax reaches a predefined threshold. RESULTS: All groups of alcohol abusers had significantly elevated endotoxin plasma levels with a considerable portion of 'bound' endotoxin. Conversely, the endotoxin binding capacity was markedly diminished, mainly in patients with more advanced liver disease (A1: 85.8% of the control value [non-significant vs. controls]; A2: 25.4% [p<0.05]; A3: 43.6% [p<0.02], NC: 43.2%). CONCLUSIONS: The endotoxin-binding capacity is diminished in patients with alcoholic and non-alcoholic cirrhosis, as well as in less advanced alcoholic liver disease. Reduced endotoxin binding may contribute to the adverse effects of endotoxemia.
Adult↗
A sensitive chromogenic Limulus amoebocyte lysate micro-assay for detection of endotoxin in human plasma and in water.
This chromogenic endotoxin assay involves a 45 min incubation of plasma extract or water with a mixture of Limulus amoebocyte lysate and the chromogenic substrate S-2423. Absorbance is measured in micro-titre plates. The assay allows the detection of 0.2 pg endotoxin per ml in water (0.002 Endotoxin Units/ml) and 1 pg endotoxin per ml in plasma (0.012 Endotoxin Units/ml). The intra-assay coefficient of variation is less than 5%.
Aniline Compounds↗
Chronic and intradialytic effects of high-flux hemodialysis on tumor necrosis factor-alpha production: relationship to endotoxins.
Tumor necrosis factor-alpha (TNF alpha) likely plays a role in hemodialysis-associated complications. As TNF alpha is mainly produced by monocytes in response to endotoxins, we studied its production and the presence of circulating endotoxins in patients dialyzed on polyacrylonitrile (PAN) membrane. Spontaneous production of TNF alpha was observed in patients before the dialysis session and increased during the session. Endotoxins were present in serum from patients chronically dialyzed with PAN and increased during hemodialysis session. In addition, intradialytic decrease in CD14 antigen expression on circulating monocytes, which could be caused by endotoxins, was found. The continuous presence of low amounts of circulating endotoxins between sessions may explain the chronic increase in TNF alpha secretion, while high amounts of circulating endotoxins may account for intradialytic oversecretion of TNF alpha and downmodulation of CD14. We suggest that endotoxin-free dialysates should be a prerequisite for the use of high-flux membranes.
Acrylic Resins↗
Autosomal recessive polycystic kidney disease: characterization of human peritoneal and cystic kidney cells in vitro.
Renal cystic epithelia and peritoneal mesothelia from two humans with autosomal recessive polycystic kidney disease (ARPKD) were grown in culture. Cystic epithelial and mesothelial cells formed continuous monolayers in vitro. By electron microscopy, cystic renal cells exhibited a single apical cilium and numerous short, stubby microvilli, both in situ and in vitro. Mesothelial cells exhibited intra- and extracellular membrane-limited, lipid-filled vesicles and surface microvilli. Cystic kidney cells in vitro stained positive for lectins from Cancanavalia ensiformis (concanavalin A), Triticum vulgaris, Erythrina cristagalli, Ulex europeaus, and Arachis hypogaea. Immunocytochemical and lectin staining revealed the renal and peritoneal cells to be of collecting tubule and mesothelial origin, respectively. Both cell types showed large depositions of glycogen granules in the cytoplasm during propagation in certain culture media; in kidney cells, dibutyryl cyclic adenosine monophosphate (cAMP) abolished glycogen depositions. Glycogen deposition also was observed in liver tissue obtained by needle biopsy from one patient. No bacteria were cultured from nor endotoxin detected in the renal cyst fluid. Relative to serum, the cyst fluids contained low sodium, potassium, and chloride levels. Thus, cultured ARPKD cells demonstrate a number of characteristics that are different from cells derived from the autosomal dominant form of renal cystic disease (ADPKD).
Bacteria↗
Column liquid chromatography of endotoxins.
A new, fast and highly reproducible column liquid chromatographic method was elaborated for the analysis and small-scale preparative isolation of endotoxin from Serratia marcescens Bizio (ATCC No. 264). This procedure detects contaminants of such preparations with high sensitivity and it is capable of separating them from endotoxic components. Extensive heterogeneity of both 5% trichloroacetic acid and phenol-water-extracted endotoxin preparations was recorded. Heterogeneity among the endotoxic components of purified preparations could also be detected by this method. Measurements of biological activities, such as Limulus amoebocyte lysate activation, lymphoblastogenesis (mitogenicity) and tumor necrosis factor (TNF) liberation were carried out on the chromatographically separated fractions. During these studies, non-toxic but in vitro TNF-generating components of crude endotoxin extracts were also detected.
Animals↗
Association of endotoxemia with carotid atherosclerosis and cardiovascular disease: prospective results from the Bruneck Study.
OBJECTIVES: Focus of the current study was on the significance of bacterial endotoxin, which shows a variety of pro-atherogenic properties and may occur at high concentration in the circulation of infected subjects. BACKGROUND: The possibility of an infectious risk factor in atherogenesis and cardiovascular disease has stimulated research interest, but the nature of such process remains obscure. METHODS: We measured plasma endotoxin levels (LAL assay) in a random population of 516 men and women 50 to 79 years old at the 1990 baseline evaluation (Bruneck Study). End points of this prospective survey were incident (early) atherosclerosis in the carotid arteries as assessed with high-resolution Duplex ultrasound (five-year follow-up rate, 98%) and incident cardiovascular disease (follow-up rate, 100%). RESULTS: Median endotoxin concentration amounted to 14.3 pg/ml (range, 6.0 to 209.2 pg/ml). Subjects with levels beyond 50 pg/ml (90th percentile) faced a threefold risk of incident atherosclerosis (odds ratio [95% confidence interval] 2.9 [1.4-6.3]; p < 0.01). The risk associated with high endotoxin was most pronounced in subjects with chronic infections and in current and ex-smokers. Notably, smokers with low endotoxin levels and nonsmokers did not differ in their atherosclerosis risk, whereas smokers with high levels almost invariably developed new lesions. All findings emerged as independent of vascular risk factors. Similar results were obtained for incident cardiovascular disease. CONCLUSIONS: The current study yields first epidemiologic evidence that endotoxemia constitutes a strong risk factor of early atherogenesis in subjects with chronic or recurrent bacterial infections and a link in the association between cigarette smoking and atherosclerotic disease.
Aged↗
Composition of lipid A in the S and R forms of Shigella dysenteriae serovar 1.
A chemical analysis was performed of lipid A, isolated by acid hydrolysis of the lipopolysaccharide from the S and R forms of Shigella dysenteriae serovar 1. Differences in the moiety of both lipids and sugars were compared. The lipid portion consisted of a homologous series of fatty acids ranging from C12:0 to C18:0 (predominant homologues, C12:0, C14:0 and C16:0) and the homologous series of 3-hydroxy acids ranging from C12:0 to C16:0 (predominant homologue, 3-OH-C14:0). The major sugar portion consisted of D-glucosamine. The toxicity of lipid A in mice (LD50) ranged between 300-400 micrograms/mouse, and values from the Limulus amebocyte lysate assay were recorded as titres of 10(-5) to 10(-6) mg/ml.
Animals↗
Disposable TSM-biosensor based on viscosity changes of the contacting medium.
The thickness shear mode (TSM)-sensor responds to changes of mechanical properties of the material contacting the surface of the sensor. One of the material properties is the viscosity of a liquid. Abiosensor based on the TSM-resonator for the detection of endotoxin has been developed. It exploits the viscosity-density change during the reaction of endotoxin with limulus amebocyte lysate (LAL). The effect of surface properties of the sensor has been investigated to achieve better output signals. It is shown that the sensor requires a hydrophilic surface to get a better coupling between the sensor and the LAL-endotoxin solution. The TSM biosensor is able to detect an endotoxin concentration as low as 100 fg/ml by using only 50-microl standard LAL solution. The disadvantages of reusable sensors, such as the contamination from previous measurement of endotoxin and the cost of the regeneration or reclining processes of the sensor, have been eliminated by using a cost effective disposable TSM-sensor.
Animals↗
Oral endotoxin in healthy adults.
This article presents a study that measured oral endotoxin levels in healthy persons with the Limulus amoebocyte lysate microassay. Only young nonsmoking adults with a healthy dentition measured with the plaque index and a good level of oral hygiene based on a twice-daily (morning and evening) tooth-brushing regimen were admitted to this open study. Each person was required to provide two oral washings of 10 ml sterile saline solution 1 week apart. Only those volunteers without oral carriage of aerobic gram-negative bacilli were enrolled in the baseline study. A total of 15 healthy adults with a median age of 29 years (range, 25 to 43 years) were included in the trial. The mean plaque score of the group was 1.2 +/- 0.1. They all maintained a twice-daily tooth-brushing regimen unaltered throughout the sampling period. A total of 30 mouth rinses were studied. None of the samples yielded potential pathogens including aerobic gram-negative bacilli, Staphylococcus aureus and yeasts; a culturing technique based on preenrichment in nutrient medium was used. Data showed mean oral endotoxin levels of 20 ng per ml of mouth rinse; the aerobic E. coli endotoxin was used as the classical standard. This is equivalent to 1 mg of anaerobic endotoxin per ml of undiluted saliva after correcting for the 10 to 10(2) dilution factor of the mouth rinse itself and for the 10(3) times less sensitivity of anaerobic endotoxin in the Limulus amoebocyte lysate-assay. The discussion includes the physiologic and clinical benefit of the low endotoxicity of anaerobic gram-negative flora apart from the technical aspects of both culture and endotoxin assays used in the study.
Adult↗
Raised salivary endotoxin concentration as a predictor of infection in pediatric leukemia patients.
OBJECTIVE: The aim of this study was to evaluate whether salivary endotoxin could be used as a predictor of infection in pediatric patients (n = 12). STUDY DESIGN: Oropharyngeal carriage of aerobic gram-negative bacilli was monitored and salivary endotoxin concentration determined. Age-matched and gender-matched healthy children were used as controls. RESULTS: The range of salivary endotoxin concentrations in the healthy pediatric population was similar to the range previously reported for healthy adults (0-20 ng/mL; 0-240 EU/mL). CONCLUSION: It was found that salivary endotoxin was not an accurate predictor of sepsis and did not correlate with oropharyngeal carriage of aerobic gram-negative bacilli.
Adolescent↗
Influenza vaccination and Guillain Barre syndrome.
Acute and severe Guillain Barre Syndrome (GBS) cases reported following influenza vaccine to the Vaccine Adverse Events Reporting System (VAERS) database from 1991 through 1999 were examined. Endotoxin concentrations were measured using the Limulus amebocyte lysate assay in influenza vaccines. There were a total of 382 cases of GBS reported to the VAERS database following influenza vaccination (male/female ratio, 1.2). The median onset of GBS following influenza vaccine was 12 days (interquartile range, 7 days to 21 days). There was an increased risk of acute GBS (relative risk, 4.3; 95% confidence interval, 3.0 to 6.4) and severe GBS (relative risk, 8.5; 95% confidence interval, 3.7 to 18.9) in comparison to an adult tetanus-diphtheria (Td) vaccine control group. There were maximums in the incidence of GBS following influenza vaccine that occurred approximately every third year (1993, 1996, and 1998) and statistically significant variation in the incidence of GBS among different influenza manufacturers. Influenza vaccines contained from a 125- to a 1250-fold increase in endotoxin concentrations in comparison to an adult Td vaccine control and endotoxin concentrations varied up to 10-fold among different lots and manufacturers of influenza vaccine. The biologic mechanism for GBS following influenza vaccine may involve the synergistic effects of endotoxin and vaccine-induced autoimmunity. There were minimal potential reporting biases in the data reported to the VAERS database in this study. Patients should make an informed consent decision on whether to take this optional vaccine based upon its safety and efficacy and physicians should vigilantly report GBS following influenza vaccination to the VAERS in the United States so that continued evaluation of the safety of influenza vaccine may be undertaken.
Adolescent↗
Aqueous extract isolated from Platycodon grandiflorum elicits the release of nitric oxide and tumor necrosis factor-alpha from murine macrophages.
Herbal medicines are increasingly being utilized to treat a wide variety of disease processes. Aqueous extract from the root of Platycodon grandiflorum A. DC (Campanulaceae), Changkil (CK), is reported to have antitumor and immunomodulatory activities; however, the mechanism underlying its therapeutic effect is not known. In the present study we examined the effects of CK on the release of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha), and on the gene expression of iNOS and TNF-alpha in mouse macrophages. CK elicited a dose-dependent increase in NO and TNF-alpha production in cultured macrophages. CK significantly affected secretion at concentrations of more than 5 micrograms/ml, and its maximum effect was at concentration of 100 micrograms/ml. Reverse transcription polymerase chain reaction showed that increases in NO and TNF-alpha secretion were due to an increase in inducible NO synthase mRNA and TNF-alpha mRNA, respectively. Transient expression assays with NF-kappa B binding sites linked to the luciferase gene revealed that CK-induced increase of inducible NO synthase mRNA and TNF-alpha mRNA were mediated by the NF-kappa B transcription factor complex. These results demonstrate that CK stimulates NO and TNF-alpha release and is able to upregulate iNOS and TNF-alpha expression through NF-kappa B transactivation and this may be a mechanism whereby this herbal medicine elicits its therapeutic effects.
Animals↗
Bartonella quintana lipopolysaccharide effects on leukocytes, CXC chemokines and apoptosis: a study on the human whole blood and a rat model.
Bartonella quintana, an emerging gram-negative pathogen, may cause trench fever, endocarditis, cerebral abscess and bacillary angiomatosis usually with the absence of septic shock in humans. B. quintana lipopolysaccharide (LPS), a deep rough endotoxin with strong reactivity in the limulus amebocyte lysate (LAL)-assay, was studied in human whole blood and in a rat model. A significant (P<0.05) increase of interleukin-8 (IL-8) concentration, comparable to the level induced by enterobacterial LPS, was stimulated in the human whole blood by B. quintana LPS. Isolated human neutrophils delayed their apoptotic behavior in the presence of B. quintana LPS. In the rat, B. quintana LPS induced a significant (P<0.001) increase in white blood cell count, both 30 and 60 min after intravenous injection. Such leukocytosis was inhibited by pretreatment with prazosin, an alpha-adrenergic antagonist. B. quintana LPS did not significantly change heart rate (HR), hematocrit (HCT) and platelet count in the above reported in vivo model, and regarding mean blood pressure (MAP) only a very early (5 min after LPS) and mild (yet significant) hypotension was observed. In contrast, a long-lasting decrease of MAP was found in Salmonella minnesota R595 LPS-treated animals. Blood TNFalpha levels did not change significantly from the baseline in rats injected with either saline or with B. quintana LPS, on the contrary S. minnesota R595 LPS-injected animals showed substantial increase of TNFalpha levels up to 2924 pg/ml at 60 min after LPS injection. B. quintana LPS as well as Salmonella LPS-injected rats exhibited an increase of the blood levels of GRO/CINC-1, particularly at 240 min after LPS administration. Apical part of rat gut villi showed several TUNEL-positive cells in tissue sections from B. quintana LPS-treated animals. Taken together, our data demonstrates that B. quintana LPS is able to selectively stimulate some inflammatory mediators. B. quintana LPS-induced leukocytosis appears mediated by an alpha-adrenergic receptor. The delayed apoptotic process of leukocytes and the chemokine increase may explain the apoptotic cells found in the rat gut and the inflammatory reactions in some human Bartonella diseases. This peculiar inflammatory pattern induced by B. quintana LPS, may partially account for the lack of severe septic shock, observed in human B. quintana infections.
Animals↗