Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Limulus Test”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources
PubMed2001

Relationship between plasma D(-)-lactate and intestinal damage after severe injuries in rats.

AIM: To explore the kinetic changes in plasma D(-)-lactate and lipopolysaccharide (LPS) levels, and investigate whether D(-)-lactate could be used as a marker of intestinal injury in rats following gut ischemia/reperfusion, burn, and acute necrotizing pancreatitis (ANP). METHODS: Three models were developed in rats: (1)gut ischemia/reperfusion obtained by one hour of superior mesenteric artery occlusion followed by reperfusion; (2)severe burn injury created by 30% of total body surface area (TBSA) full-thickness scald burn; and (3)ANP induced by continuous inverse infusion of sodium taurocholate and trypsin into main pancreatic duct. Plasma levels of D(-)-lactate in systemic circulation and LPS in portal circulation were measured by enzymatic-spectrophotometric method and limulus amebocyte lysate (LAL) test kit, respectively. Tissue samples of intestine were taken for histological analysis. RESULTS: One hour gut ischemia followed by reperfusion injuries resulted in a significant elevation in plasma D(-)-lactate and LPS levels, and there was a significant correlation between the plasma D(-)-lactate and LPS (r = 0.719, P<0.05). The plasma concentrations of D(-)-lactate and LPS increased significantly at 6h postburn, and there was also a remarkable correlation between them (r=0.877 P<0.01). D(-)-lactate and LPS levels elevated significantly at 2h after ANP, with a similar significant correlation between the two levels (r = 0.798, P < 0.01). The desquamation of intestine villi and infiltration of inflammatory cells in the lamina propria were observed in all groups. CONCLUSION: The changes of plasma D(-)-lactate levels in systemic blood paralleled with LPS levels in the portal vein blood. The measurement of plasma D(-)-lactate level may be a useful marker to assess the intestinal injury and to monitor an increase of intestinal permeability and endotoxemia following severe injuries in early stage.

Animals↗
PubMed1975

Preliminary study of appearance of endotoxin in circulatiory system of sheep and cattle after induced grain engorgement.

Edotoxin was detected, using the limulus amebocyte lysate (LAL) test, in the blood of 3 sheep and 1 steer which had been experimentally "overfed" (induced grain engorgement) with a mixture of corn and oats (2:1). The 1st postfeeding blood samples were collected 24 hours after overfeeding. In 2 sheep and 1 steer, the 24-hours blood samples were test positive. In 1 sheep which died, the 48-hour blood sample was the 1st test-positive sample. In all cases, pre-overfeeding blood samples were taken just before overfeeding.

Animal Feed↗
PubMed2001

[The effects of gut -- origin lipopolysaccharide translocation on the apoptosis of lymphocytes in scalded rats].

OBJECTIVE: To investigate the relationship between lymphocyte apoptosis in spleen and mesenteric lymph nodes (MLNs) and gut -- origin lipopolysaccharide (LPS) translocation after severe scalding in rats. METHODS: Wistar rats inflicted 30% TBSA III degree scalding were employed as the model. Serum LPS levels in portal vein and vena cava were determined by limulus amebocyte lysate (LAL) test. Apoptotic lymphocytes in paraffin -- embedded spleen and MLNs sections were detected with TdT -- mediated and dUTP nick end labeling (TUNEL) and peroxidase (POD) staining. The images were taken by cooldccd camera system, and the count and optical density (OD) value of apoptotic lymphocytes were analyzed with software Spot and Imagine proplus 4.10a (IPP4.10a). RESULTS: Serum LPS levels in portal vein and vena cava increased sharply in rats postburn (P < 0.01) and reached a peak value at 6 postburn hour (PBH). LPS level in portal vein was higher than that in vena cava (P < 0.01) in the period of 3 to 48 PBHs. The results of TUNEL -- POD staining and the count of apoptotic lymphocytes showed that the apoptotic cells were few in normal MLNs, but increased obviously postburn (P < 0.01), especially at 3 PBH. On the contrary, apoptotic lymphocytes were concentrated in spleen cortex before injury and decreased obviously postburn (P < 0.01), though a slight recovery was found after 24 PBH. Optical density of apoptotic lymphocytes was significantly reduced in spleen at 24 PBH, But the OD value of apoptotic lymphocytes in MLNs increased significantly within 48 PBHs when compared with that before injury (P < 0.01). CONCLUSION: Gut -- origin endotoxemia in rat could occur in early postburn period. The LPS translocation might induce lymphocyte apoptosis in MLNs. The decreased apoptotic lymphocytes in spleen implied abnormal immune function in spleen.

Animals↗
PubMedDate not supplied

Wet heat inactivation of lipopolysaccharide from E. coli serotype 055:B5.

Wet heat inactivation of lipopolysaccharide (LPS) from E. coli Serotype 055:B5 was investigated. The LPS solutions were heated at study temperatures ranging from 78 degrees C to 175 degrees C, and were assayed using the Limulus Amebocyte Lysate (LAL) test. Plots of the log of the amount of endotoxin remaining versus heating time showed biphasic decreases. The initial slopes are associated with a faster rate of decrease to about a 0.5-log unit reduction, and were followed by a slower, linear rate of decline in the secondary slopes. The curves were applied to the biexponential model expressed by the equation (Et = E1e-klt + E2e-k2t). The LPS inactivation rates (k1 and k2) each conformed to their own Arrhenius equation. Therefore, the processes required to achieve the desired level of LPS inactivation can be obtained by mathematical means.

Escherichia coli↗
PubMed2001

[Effects of different disinfectants on levels of endotoxin in canals of chronic periapical periodontitis].

OBJECTIVE: The objective of this study is to compare effects of formocresol, camphorated phenol and Ya Kan (metronedazole) on endotoxin levels in canals of chronic periapical periodontitis. METHODS: A total of 30 patients with chronic periapical periodontitis were selected from outpatients, and 10 cases each were randomly picked out to treat by sealing with formocresol, camphorated phenol and Ya Kan respectively. All patients were both sampled before and after sealing of these disinfectants, and chromogenic substrate method of limulus amebocyte lysate (LAL) test was used to measure levels of endotoxin. RESULTS: The effects of Ya Kan, formocresol and camphorated phenol on levels of endotoxin did not showed significant difference. CONCLUSION: Some anti-anaerobic bacterial drugs can be used to treat chronic periapical periodontitis.

Anti-Infective Agents, Local↗
PubMed2004

[Investigation of infection risk and the value of antibiotic prophylaxis during transrectal biopsy of the prostate by endotoxin determination].

OBJECTIVE: To clarify the value of endotoxin determination in evaluating the infection risk and antibiotic prophylaxis during transrectal biopsy of the prostate. METHODS: Forty-eight patients were divided into four groups randomly. Group A (12 patients) were not treated before biopsy. Group B (13 patients) received antibiotic prophylaxis therapy. Group C (12 patients) underwent clusis. Group D (11 patients) received combined treatment. Urine and blood samples of the patients were obtained before and after prostatic biopsy. All samples were cultured for bacteria and investigated for endotoxin concentration by limulus quantitative azo color test. RESULTS: No significant difference in either serum endotoxin or blood bacterial cultures was noted before and after prostatic biopsy (P < 0.05) in all the groups. A significant increase was observed in urine endotoxin after biopsy compared with that before biopsy in Groups A and B (P < 0.05). There was no significant increase in urine endotoxin after biopsy compared with that before biopsy in Group C and D. The positive incidence of urine bacterial culture was significantly increased (P < 0.05) in patients of Group A and B. CONCLUSION: Circulation infection risk following prostatic biopsy was low. Changes of urinary infection were fewer in patients who had undergone clusis and/or antibiotic prophylaxis than in those who had received no or only antibiotic prophylaxis therapy. Endotoxin determination in urine is a reliable, sensitive and simple method for diagnosis of bacterial infection in patients undergoing transrectal biopsy of the prostate.

Aged↗
PubMed2004

[The expression of RANTES interleukin 1beta and endotoxin in the effusion of secretory otitis media].

OBJECTIVE: To study the protein expression of endotoxin, interleukin 1beta (IL-1beta) and regulated upon activation, normal T expressed and secreted (RANTES) in effusions of secretory otitis media and their roles in the pathogenesis of secretory otitis media. METHOD: Seventy-two effusion samples were taken from 53 patients with secretory otitis media by tympanocentesis. After swabs they were taken for bacteria culture. Limulus amebocyte lysate (LAL) test was used to quantify the content of endotoxin, radioimmunoassay to analyze the level of IL-1beta and enzyme-linked immunosorbent assay (ELISA) to detect the concentration of RANTES. RESULT: Endotoxin, IL-1beta and RANTES were detectable in 80.9%, 77.8% and 70.8% of middle ear effusion, with mean levels of (35.2 +/- 51.6) EU/ml, (1.10 +/- 0.84) microg/L and (0.52 +/- 0.43) microg/L respectively. All of them showed higher concentration in the mucoid-type effusions than those in the serous-type effusions (P<0.05). Higher levels of the endotoxin and RANTES (P<0.05) were found in longer course patients. The effusions with positive bacteria culture displayed more abundant endotoxin, IL-1beta and RANTES protein than those with negative culture. Significant correlations were found between endotoxin and IL-1beta (r = 0.74, P<0.01), also between IL-1beta and RANTES (r = 0.48, P<0.01). CONCLUSION: Endotoxin, IL-1beta and RANTES may take part in maintaining the inflammatory response in the tympanic cavity and stimulating mucin secretion. It indicates that they play an important role in the immune pathogenesis of secretory otitis media.

Adolescent↗
PubMed2004

Health complaints from workplace exposure to bioaerosols: a questionnaire study in sewage workers.

A questionnaire study was performed in 99 workers at a large sewage treatment plant to investigate self-reported health complaints from workplace exposure to bioaerosols. The study population was divided into subgroups according to different work stations: mechanical treatment (MT), biological treatment (BT), sewage sludge treatment (SST) and operation control (OC). The questionnaire included personal data, workpost and job characteristics, exposure to chemicals, history of employment and exposure, workplace hygiene and protective measures, smoking and drinking habits. There was also a series of 25 questions on subjective health complaints grouped into the following clusters: 'flu-like symptoms', 'respiratory symptoms', 'nose, eye, throat and skin irritation', 'neurological symptoms' and 'gastrointestinal symptoms'. Each subject was asked whether the complaints had occurred 'frequently', 'rarely', or 'never' within the previous 12 months. Air concentrations of endotoxins and (1 --> 3)- beta-D-glucans in the worker's breathing zone were also determined. The measurements of concentrations were made in the summertime during a morning shift. To determine endotoxins concentration, the Chromogenic Limulus Amebocyte Lysate (LAL) Test was applied. The questionnaire data and determination results were subject to a statistical analysis. No statistically significant relationship was found between the reported health complaints and such variables as job title, exposure to endotoxins and glucans, tobacco smoking, age and period of employment as sewage worker. The findings revealed that among the complaints, muscle and joint ache was reported most frequently, while among the symptom clusters, the flu-like symptoms prevailed. These symptom clusters occurred most frequently in OC workers, and were least often found in SST workers. In the worker's breathing zone, the geometric mean concentration of endotoxins amounted to 20.3 ng/m3 and of glucans to 7.76 ng/m3, and was not related to job title or job characteristics. A high correlation was found between endotoxins and (1 --> 3)- beta -D-glucans concentrations (Pearson correlation coefficient 0.86, p < 0.0005).

Adult↗
PubMed1990

Approach to diagnosis of meningitis. Cerebrospinal fluid evaluation.

CSF evaluation is the single most important aspect of the laboratory diagnosis of meningitis. Analysis of the CSF abnormalities produced by bacterial, mycobacterial, and fungal infections may greatly facilitate diagnosis and direct initial therapy. Basic studies of CSF that should be performed in all patients with meningitis include measurement of pressure, cell count and white cell differential; determination of glucose and protein levels; Gram's stain; and culture. In bacterial meningitis, Limulus lysate assay and tests to identify bacterial antigens may allow rapid diagnosis. Where there is strong suspicion of tuberculous or fungal meningitis, CSF should also be submitted for acid-fast stain, India ink preparation, and cryptococcal antigen; unless contraindicated by increased intracranial pressure, large volumes (up to 40-50 mL) should be obtained for culture. If a history of residence in the Southwest is elicited, complement-fixing antibodies to Coccidioides immitis should also be ordered. Newer tests based on immunologic methods or gene amplification techniques hold great promise for diagnosis of infections caused by organisms that are difficult to culture or present in small numbers. Despite the great value of lumbar puncture in the diagnosis of meningitis, injudicious use of the procedure may result in death from brain herniation. Lumbar puncture should be avoided if focal neurologic findings suggest concomitant mass lesion, as in brain abscess, and lumbar puncture should be approached with great caution if meningitis is accompanied by evidence of significant intracranial hypertension. Institution of antibiotic therapy for suspected meningitis should not be delayed while neuroradiologic studies are obtained to exclude abscess or while measures are instituted to reduce intracranial pressure.

Cerebrospinal Fluid↗
PubMed1989

Plasma proteolysis and circulating cells in relation to varying endotoxin concentrations in porcine endotoxemia.

Ten juvenile pigs receiving a continuous infusion of 0.01 mg/kg of endotoxin over 3 hr and seven animals infused with sterile saline (serving as controls) were studied for 5 hr. Endotoxin concentrations in plasma as determined with a chromogenic Limulus amoebocyte lysate (LAL) test reached a steady state of about 1,000 ng/liter after 1 hr and declined rapidly as the infusion was discontinued. Preinfusion values were reached at the end of the observation period. Endotoxin concentrations found during the infusion period were comparable with those seen in humans with septicemia. The endotoxin infusion was followed by hemoconcentration, leukocytopenia, and thrombocytopenia. Using chromogenic peptide substrate assays, activation of the plasma kallikrein-kinin, fibrinolytic, and coagulation systems was detected. Although the endotoxin concentrations reached preinfusion values within the last 2 hr of the observation period, changes found in circulating cells and components of the plasma cascade systems did not normalize, and the hemodynamic situation did not change.

Animals↗
PubMedDate not supplied

Easy production of sterile, pyrogen-free dialysate.

Hemodialysis (HD) hypotension is frequently encountered during conventional acetate HD. Recently it has been suggested that monocytes that adhere to the dialysis membrane are also stimulated by endotoxins diffusing from the dialysate side. Stimulated monocytes, however, release interleukin-1, which mediates fever and hypotension through its action on the cyclo-oxygenase cascade. To prevent this endotoxin-induced stimulation of monocytes, a hemofilter with a polyamide membrane (FH 88, Gambro, Lund, Sweden, cut-off 20,000 daltons, surface area 2.0 m2) was interposed between the dialysate outlet of the HD machine and the dialyzer. The data obtained clearly show that the filtered dialysate was always pyrogen-free when tested with a limulus-amebocyte-lysate assay. In addition, in 80% of cases no bacteria were detected after the sterilizing filter. Almost no febrile episodes were observed when sterile dialysate was used.

Biological Assay↗
PubMed1993

[A quality control for the culture system using endotoxin assays in human in vitro fertilization and embryo transfer].

The purpose of this study is to investigate the effects of endotoxin on human in vitro fertilization and embryo transfers (IVF-ET) and to evaluate a quality control system for a culture medium using endotoxin assays. Before the final water purification (in an ultra-pure water system with a depyrogen filter) of the medium, the sources of water were pre-purified as follows; (I) distillation-->deionization x 2, (II) distillation-->ultra-pure water system or (III) reverse osmosis system. The limulus amebocyte lysate gelation tests (sensitivities of 0.03 and 0.25EU/ml) were used to detect endotoxin in the medium and in pre-purified water (pre-water). No pregnancies occurred in the endotoxin-positive medium (endotoxin > or = 0.03EU/ml). The endotoxin-negative medium resulted in a 33.3% pregnancy rate and 13.4% implantation rate. No statistical differences in the implantation rate were found among these methods of pre-purification (I: 12.5%, II: 13.4% and III: 20.0%). Endotoxin was detected in all the pre-water between 0.25 and 4.0EU/ml. The clinical pregnancy rate (36.6%) and the implantation rate (16.9%) in pre-water of endotoxin < 0.25EU/ml were significantly higher than those (10.5% and 5.5%) in pre-water of endotoxin > or = 0.25EU/ml (p < 0.05). We confirmed that a very low concentration of endotoxin disturbed a human embryo implantation. Endotoxin assays, not only in the media, but also in pre-water before final purification are useful as a quality control for the IVF-ET program.

Culture Media↗
PubMed1997

Kinetics of plasma cytokines and its clinical significance in patients with severe trauma.

OBJECTIVE: To examine the kinetics of plasma tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) in patients with severe trauma and to discuss their relationship with organ damage and endotoxemia. METHODS: Seventeen patients (10 men and 7 women) with severe trauma were selected in this study. Their mean age was 37.9 +/- 11.9 years. All patients were divided into two groups according to injury severity score (ISS): group I with ISS from 16-25 (18.8 +/- 2.9, n = 10) and group II with ISS more than 25 (34.3 +/- 8.3, n = 7). Ten young healthy volunteers (6 men and 4 women) were used as controls. Plasma TNF alpha and IL-8 levels were assayed with enzyme-linked immunosorbent assay. IL-6 activity in the plasma was determined by bioassay with IL-6-dependent cell-line 7TD1. Limulus amebocyte lysate chromogenic test was used for plasma endotoxin assay. RESULTS: Plasma cytokine levels in patients with trauma had a successively significant increase. Plasma TNF level increased earlier. Increases in plasma IL-6 and IL-8 occurred later. All the increases were significantly correlated with the severity of trauma and organ damage after trauma. In addition, obvious endotoxemia occurred at the early stage of trauma and was significantly correlated with the severity of trauma and the levels of plasma TNF alpha, IL-6 and IL-8. CONCLUSIONS: Release of TNF alpha, IL-6 and IL-8 can be significantly increased in patients with severe trauma. The increase may be related to massive endotoxin translocation and may play an important role in the development of organ damage after trauma.

Adolescent↗
PubMed1986

Comparison of the standard pour plate procedure and the ATP and Limulus amebocyte lysate procedures for the detection of microbial contamination in intravenous fluids.

The intrinsic and extrinsic microbial contamination of large-volume parenterals has been associated with bacteremias in hospitalized patients. When epidemiologic data suggest the association of contaminated intravenous (i.v.) fluids with disease, appropriate laboratory methods must be devised to analyze quickly the suspect fluid. A study was undertaken to compare three laboratory test methods (standard pour plate [SPP] technique, ATP procedure, and Limulus amebocyte lysate [LAL] assay) for detecting the presence of microorganisms in artificially contaminated i.v. fluid. SPP proved the most sensitive of the assay techniques used, but a 24-h period was required for microbial growth. The LAL assay appeared more sensitive in detecting i.v. contamination than the ATP method. These studies suggest that the LAL and ATP methods can be used for the rapid detection of microbial contamination in i.v. fluid. SPP and LAL procedures would have practical laboratory application when the contamination of i.v. fluids is suspected, and they are more sensitive in detecting microbial contamination in these solutions than the ATP method.

Adenosine Triphosphate↗
PubMed1985

Ideal properties of a LAL reagent for pharmaceutical testing.

Evaluation of medical devices and pharmaceutical products for endotoxin content is the most significant biomedical application of Limulus amebocyte lysate (LAL). This review summarizes the means by which LAL reagent suppliers have introduced different production techniques and formulation additives to uniquely optimize their products for industry. Pharmaceutical testing requires a LAL reagent that is buffered, stabilized to a sensitivity of 0.12 EU/ml, optimized to detect E. coli-derived LPS in water, formulated to produce firm opaque gels, designed specifically to detect bacterial endotoxin, and is economical. Unique LAL reagent characteristics produce nonuniformity in drug compatibility testing but does not significantly alter detection of unsafe levels of native endotoxin. Design of a clinical LAL reagent may require additional means for standardization and exclusion of additives which are only useful for pharmaceutical testing. A cooperative effort between clinical investigators and the LAL industry should resolve these issues in a reasonable period of time.

Drug Industry↗
PubMed2003

Comparative evaluation of the human whole blood and human peripheral blood monocyte tests for pyrogens.

Two different in vitro tests for pyrogens, using human peripheral blood monocytes (PBMNC) and diluted whole blood (WBC), respectively, were applied to different classes of parenteral medicinal products. Many of these products did not have a specified endotoxin limit concentration that was established as the maximum valid dilution to comply with the test. The results of the in vitro tests for pyrogens were compared with the results from the Limulus amoebocyte lysate (LAL) and rabbit pyrogen tests. The Second International Standard for endotoxin was used to calibrate all of the assays and the International Standard for IL-6 was used to calibrate the IL-6 ELISA which provided the readout for the in vitro tests for pyrogens. Preparatory tests were conducted to ensure that the "criteria for validity and precision of the standard curve" were satisfied and that the drugs being tested did not interfere in the tests. The PBMNC/IL-6 test had a detection limit of 0.06 EU/ml and spike recoveries were 62-165%. The whole blood/IL-6 test also had a detection limit of 0.06 EU/ml and spike recoveries were 58-132%. The application to the detection of non-endotoxin pyrogens needs to be evaluated in more detail, but the two in vitro tests for pyrogens showed good agreement overall, both with each other and with the LAL test and the rabbit pyrogen test for the detection of endotoxins.

Animals↗
PubMed2005

Inhibition evaluation for a 20-min endotoxin limit test on FDG.

OBJECTIVES: In chemical quality control tests for 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG), gel time is inversely related to endotoxin concentration. Solutions for positive product control (PPC) and positive water control (PWC) should contain a highly concentrated endotoxin level. The aims of our study were to derive an endotoxin concentration that causes PPC and PWC to gel and to evaluate inhibitory effects caused by FDG on gel formation in PPC and PWC test solutions. METHODS: At expiration, the maximum administered total dose (in millilitres) of FDG should contain fewer than 175 endotoxin units (EU). Our average batch volume of FDG is 15 ml; thus, the minimum endotoxin limit should be 12 EU x ml(-1) . Twelve tubes were tested for each of four concentrations. Inhibition was assessed using Limulus amoebocyte lysate reagent, depyrogenated vials, and pyrogen-free sterile micropipette tips. Each study was performed with four groups of solutions: decayed 18F-FDG, negative control, PPC and PWC. RESULTS: In the study of undiluted FDG, seven of 50 PPC vials at 12 EU x ml(-1) did not gel. The lowest endotoxin concentration that consistently gelled at 20 min was 4 EU x ml(-1) . In the sample tested for inhibition using PPC tubes at 4 EU x ml(-1) , 49 tubes gelled at 20 min, and one did not. CONCLUSION: The inhibition rate improved between undiluted (i.e., 7/50 (14%)) and diluted (i.e., 1/50 (2%)) FDG PPC trials (P=0.03). However, given that 1 of 50 trials failed for diluted FDG PPC, we conclude that inhibition still occurs and there is a 95% chance that the inhibition rate could be as high as 11% or as low as 0% on repetition of the experiment.

Artifacts↗
PubMed1988

[Comparison of three miniaturized Limulus-amoebocyte-lysate methods].

Comparative examinations with three different micro-models for the LAL-test methods,--namely the capillary test, Endotoxin-test "Mini" and Coatest-Endotoxin-method-, tested with 11 Enterobacteriaceae- and 6 Pseudomonas-type-strains and isolates from foods gave only slight differences for the endotoxin content. Out of 250 single measurements per test method the capillary test as well as the Coatest-Endotoxin-method gave count limits between 2.8 X 10(1) and 7.4 X 10(3) CFU/ml. For the endotoxin-test method "Mini" the limits were one log unit higher-namely between 8.6 X 10(2) and 5.0 X 10(4) CFU/ml. The maximum values for count limits of all three methods correspond to approximately 1 ng Endotoxin. For the two gel test methods a relative error of +/- 15% has to be taken into account; for the chromogen method however, the relative error lies within +/- 25%, if the concentration is 0.0125 ng LPS/ml or lower. Between 0.025 and 0.1 ng LPS/ml or 0.075 and 0.1 ng LPS/ml the relative error is reduced to +/- 16% and +/- 5% respectively. The study has shown that the three micro tests in question as tested with pure cultures give comparable and reproducible results; inspite of the high relative error.

Animals↗