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 1,045 records · Page 58Linked to original sources
PubMed1994

[Specific assay for endotoxin using immobilized histidine. Application to serum sample].

The amount of endotoxin in the serum was measured by the new assay method of endotoxin using a filtercup, Limulus amebocyte lysate, and immobilized histidine which is a specific adsorbent for endotoxin. The maximum recovery of endotoxin in the rabbit serum was obtained using acetate buffer (pH 5.5, mu = 0.1) for the adsorption. Using this buffer, various kinds of endotoxin in water were adsorbed quantitatively on immobilized histidine, and the activity of the adsorbed endotoxin was well recovered. The value of the amount of endotoxin in the bovine serum measured by the new assay method, which includes heat treatment (70 degrees C, 10 min) after separation followed by washing, was closer to that calculated from pyrogenic activities in rabbits than that measured by the PCA-Toxicolor method.

Animals↗
PubMed1984

Involvement of central action of lipopolysaccharide in pyrogen fever.

To elucidate the mechanisms of fever response by bacterial pyrogen (lipopolysaccharide, LPS), we investigated both pyrogenicity and Limulus amoebocyte lysate (LAL) gelation activity of cerebrospinal fluid (CSF) withdrawn from febrile rabbits induced by i.v. injection of LPS. One ml of CSF was withdrawn from donor animals 2 hr after i.v. injection of E. coli LPS at graded doses of O, 1, 10 and 50 micrograms/kg, and its pyrogenicity was checked by administration into cisterna magna of recipient animals. Pyrogenicity was revealed only in the CSF withdrawn from the group injected with 50 micrograms/kg of LPS. Differences of both protein content and concentrations of ions (Na, K and Ca) were not obtained among the CSF withdrawn from control and LPS-injected groups. All of the above CSF had no LAL gelation activity, but the activity could be detected in the CSF withdrawn from animals injected with a higher dose of LPS (500 micrograms/kg, i.v.). LAL gelation activity of LPS dissolved in normal CSF was 2 orders less potent in comparison with that of LPS dissolved in saline, which suggested the presence of inhibitor(s) in CSF for LAL assay. Pyrogenicity was not revealed in the CSF withdrawn from hyperthermic rabbits induced by administration of reserpine after pretreatment with a monoamine oxidase inhibitor. These findings suggest that the central action of LPS is involved in pyrogen fever and that monoamines are not closely related to pyrogen fever.

Animals↗
PubMed2005

Within-home versus between-home variability of house dust endotoxin in a birth cohort.

Endotoxin exposure has been proposed as an environmental determinant of allergen responses in children. To better understand the implications of using a single measurement of house dust endotoxin to characterize exposure in the first year of life, we evaluated room-specific within-home and between-home variability in dust endotoxin obtained from 470 households in Boston, Massachusetts. Homes were sampled up to two times over 5-11 months. We analyzed 1,287 dust samples from the kitchen, family room, and baby's bedroom for endotoxin. We fit a mixed-effects model to estimate mean levels and the variation of endotoxin between homes, between rooms, and between sampling times. Endotoxin ranged from 2 to 1,945 units per milligram of dust. Levels were highest during summer and lowest in the winter. Mean endotoxin levels varied significantly from room to room. Cross-sectionally, endotoxin was moderately correlated between family room and bedroom floor (r = 0.30), between family room and kitchen (r = 0.32), and between kitchen and bedroom (r = 0.42). Adjusting for season, the correlation of endotoxin levels within homes over time was 0.65 for both the bedroom and kitchen and 0.54 for the family room. The temporal within-home variance of endotoxin was lowest for bedroom floor samples and highest for kitchen samples. Between-home variance was lowest in the family room and highest for kitchen samples. Adjusting for season, within-home variation was less than between-home variation for all three rooms. These results suggest that room-to-room and home-to-home differences in endotoxin influence the total variability more than factors affecting endotoxin levels within a room over time.

Air Pollutants↗
PubMed1999

Biological activities of lipopolysaccharides extracted from porcine vaccine strains.

Lipopolysaccharides (LPSs) were purified from Actinobacillus pleuropneumoniae serotype 2, Bordetella bronchiseptica and Haemophilus parasuis serotype 5, which were used for vaccine production in Japan, by the phenol-water procedure. In SDS-PAGE analysis, A. pleuropneumoniae LPS, as well as Escherichia coli LPS, demonstrated a typical ladder profile of a smooth-type LPS. On the other hand, B. bronchiseptica and H. parasuis LPSs lacked the ladder profiles. It was found that the biological activity of these LPSs was comparable to those of E. coli LPS in terms of activation of the clotting enzyme of Limulus amoebocyte lysate, mitogenic activity of mouse spleen cells, stimulation of TNF-alpha and nitric oxide production, but IL-6 production could hardly be observed in any LPS.

Actinobacillus Infections↗
PubMed2002

Clinical implications of endotoxin concentrations in vaccines.

BACKGROUND: A previous study suggested that high concentrations of endotoxin may be present in whole-cell diphtheria/tetanus/pertussis (DTP) vaccine, and the scientific literature contains many studies examining the reactivity of whole-cell DTP vaccine. The medical and scientific communities have previously reported that the presence of endotoxin in commercial vaccines may have negative effects on vaccine recipients. OBJECTIVE: To determine the endotoxin concentrations in whole-cell DTP, acellular DTP(DTaP), and DT vaccines and determine the clinical experience with each vaccine. METHODS: To study the endotoxin concentrations in vaccines, the Limulus amebocyte lysate (LAL) assay was used. The vaccines analyzed with the LAL assay were whole-cell DTP vaccine lots manufactured by Connaught, Lederle, the Michigan and Massachusetts Departments of Health, and Wyeth; DTaP vaccine lots manufactured by Merieux and Takeda; and DT vaccine lots manufactured by Wyeth and Lederle. The incidence of adverse reactions following whole-cell DTP, DTaP, and DT vaccines were determined based on analysis of the Vaccine Adverse Events Reporting System (VAERS) database. RESULTS: The results of the LAL assay showed that whole-cell DTP vaccines contained considerably more endotoxin than either DTaP or DT vaccines. The VAERS showed that statistically significantly more adverse reactions were associated with whole-cell DTP vaccine than DTaP or DT vaccines. CONCLUSIONS: This analysis confirmed higher concentrations of endotoxin in whole-cell DTP vaccines compared with DTaP or DT vaccines. As high concentrations of endotoxin may be correlated with a higher incidence of adverse events, the switch from whole-cell DTP to DTaP for routine vaccinations in the US seems well justified.

Adolescent↗
PubMed1999

Pulmonary neutrophil accumulation following human endotoxemia.

OBJECTIVE: To elucidate the role of pulmonary neutrophil accumulation in the pathogenesis of human acute lung injury (ALI) following endotoxemia. DESIGN: Retrospective study. SETTING: Surgical unit in a tertiary-care university hospital. PATIENTS: Thirty-three patients who died of intra-abdominal sepsis and received an autopsy. MEASUREMENTS: Just before each patient's death, (1) plasma endotoxin was determined by the limulus gelation test, and (2) the severity of ALI was estimated by the Murray lung injury score. (3) Neutrophil accumulation in the pulmonary microcirculation was evaluated in the autopsy specimens using a computerized picture analysis method. RESULTS: (1) Endotoxin-positive patients were more likely to fall into the severe lung injury group (endotoxin-positive patients, 38% vs endotoxin-negative patients, 0%; p < 0.01). (2) The endotoxin-positive patients exhibited significantly higher neutrophil accumulation in the pulmonary microcirculation than endotoxin-negative patients (8,349 +/- 984/mm(2) vs 4,047 +/- 447/mm(2), respectively; p < 0.01). (3) Severe lung injury patients with endotoxemia had almost the same degree of neutrophil accumulation in the pulmonary microcirculation as mild-to-moderate lung injury patients with endotoxemia (8,338 +/- 1,622/mm(2) vs 8, 359 +/- 1,290/mm(2), respectively), showing a significant higher neutrophil accumulation compared to no lung injury patients without endotoxemia (5,102 +/- 410/mm(2); p < 0.01). CONCLUSION: Endotoxemia might cause ALI and pulmonary neutrophil accumulation. Pulmonary neutrophil accumulation might not be enough to cause severe lung injury (ARDS), although it is necessary to cause ALI, because the degree of pulmonary neutrophil accumulation did not correlate with the severity of ALI.

Adult↗
PubMed1981

Cotton dust and complement in vivo.

Cotton grown in Stoneville, Mississippi and harvested by three different methods was examined for anticomplementary activity in human serum in vivo. Subjects exposed to cotton dust in a model cardroom for six hours showed changes in C3c and CH50 after exposure to closed boll harvested, bract removed cotton dust when compared with a group of normal, unexposed controls. Decreases in C3c, :C4, and C3A were associated with decreases in FEV1 after exposure to closed boll harvested bract intact cotton dust. The data from this preliminary study suggest in vivo associations between inhalation of cotton dusts and complement which appear to be independent of endotoxin contamination. These findings suggest a relationship between cotton dust inhalation and complement-mediated respiratory impairment.

Adolescent↗
PubMed1978

Nitroblue tetrazolium and Limulus assays for bacteremia after dental extraction: effect of topical antiseptics.

Bacteremia that occurs after dental extraction is common. This study assessed the effect of topical antisepsis on the incidence and magnitude of post-extraction bacteremia. On hundred patients scheduled for elective tooth extraction were randomized among four groups: contr-l, mouthrinsing with sodium-p-toluene sulfonchloramide (chloramine-T), toothbrushing with chloramine-T, and irrigation with Lugol's solution. The results showed that 84% of the control group and 59% of the treatment groups had positive blood cultures (290 organisms isolated) after dental extraction. The duration and magnitude of these bacteremias were diminutive as documented by the six serial blood cultures taken for each patient, colony counts per milliliter of blood, and nitroblue tetrazolium and Limulus assays. Brushing the teeth or rinsing the mouth with chloramine-T before dental extraction significantly reduced the incidence of bacteremia (P less than .025) and the number of different organisms recovered from each patient (P less than .05). Thus, topical treatment with chloramine-T is a simple and effective means of reducing the incidence of postextraction bacteremia.

Adolescent↗
PubMed1988

Endotoxaemia in patients with Crohn's disease: a longitudinal study of elastase/alpha 1-proteinase inhibitor and Limulus-amoebocyte-lysate reactivity.

During intensive care, the severity of gut-derived systemic endotoxaemia in 16 patients with active Crohn's disease was characterized by the simultaneous determination of elastase/alpha 1-proteinase-inhibitor and Limulus-amoebocyte-lysate-reactivity. Using both assays in 15/16 patients the detectable endotoxic activity during the disease course was reflected by a parallelism between elastase/alpha 1-proteinase-inhibitor and Limulus-amoebocyte-lysate-reactivity. In 8 gut-irrigated patients, significantly lower elastase/alpha 1-proteinase-inhibitor concentrations and Limulus-amoebocyte-lysate-reactivities were measured compared with 8 gut-nonirrigated patients. The Crohn's disease activity index and the van Hees activity index as well as the inpatient time were significantly lower in lavage patients compared with gut-nonirrigated patients. It is concluded with that elastase/alpha 1-proteinase-inhibitor can be used as an alternative to the bioassayed Limulus-amoebocyte-lysate-reactivity in order to characterize systemic endotoxaemia.

Adolescent↗
PubMed1985

Endotoxemia in liver diseases: detection by a quantitative assay using chromogenic substrate with perchloric acid pretreatment.

With a quantitative blood endotoxin assay using a chromogenic substrate with a perchloric acid pretreatment (PCA-LCT), endotoxemia in various liver diseases was studied. With PCA-LCT, recovery of added endotoxin in human plasma was nearly 90%, as evidenced by an intra- and inter-assay coefficients of variation of 5.7% and 11%, respectively. Because the recovery of endotoxin was not affected in severely icteric plasmas, PCA-LCT proved to be applicable to patients with liver diseases where various degree of jaundice exist. In none of the plasmas from patients with chronic hepatitis, acute hepatitis without hepatic failure or liver cirrhosis without ascites did the endotoxin level exceed the normal range of less than 5 pg/ml. With the presence of ascites, however, endotoxemia became detectable, but at low levels and not in all cases. At the stage of hepatic failure complicated with renal failure or disseminated intravascular coagulation, endotoxemia was more frequent and endotoxin concentration greater. It is uncertain, at present, whether endotoxemia itself is deteriorating factor in hepatic failure or is merely concomitant phenomenon resulting from Kupffer cell failure.

Ascites↗
PubMed1978

The effectiveness of in vivo root planing in removing bacterial endotoxin from the roots of periodontally involved teeth.

In this study, scaling alone resulted in endotoxin values considerably greater than the values for healthy root surfaces. However, the root-planed Samples contained only about 1 ng more of endotoxin than did the healthy root surfaces. This small difference can be accounted for by the presence of small flecks of calculus left after root planing. Considering that out of a total sample size of 48 surfaces there was only 1 ng difference in the amount of endotoxin between planed teeth and uninvolved teeth, the basic conclusion must be that root planing, as performed in this study, was able to render diseased root surfaces approximately as free of detectable endotoxin as were uninvolved, healthy root surfaces of unerupted teeth.

Adult↗
PubMed1979

Hand instrumentation versus ultrasonics in the removal of endotoxins from root surfaces.

In this study, the average net total endotoxin in the solubilized extracts from each sample were healthy teeth, 1.46 ng/ml; periodontally diseased teeth, 169.5 ng/ml; ultrasonically scaled teeth, 16.8 ng/ml; root planed teeth, 2.09 ng/ml. The material that was extracted and assayed was not conclusively proven to be endotoxin, but recent studies suggest it was. Meticulous root planing as performed in this study produced values similar to those for unerupted periodontally healthy teeth. Ultrasonic scaling resulted in endotoxin values approximately eight times greater.

Adult↗
PubMed1980

Inflammatory effects of periodontally diseased cementum studied by autogenous dental root implants in humans.

The inflammatory potential of diseased cementum was studied by implanting 70 autogenous fragments from periodontally involved roots into the mucosa of 56 patients. The implants were divided into groups depending upon the type of preparation the root received prior to implantation. Fifteen healthy root fragments implanted into 15 patients served as controls. Histologic results showed that implanted fragments from roots that had been scaled caused the most response with acute inflammation up to 14 days and chronic inflammation to 21 days. In cases in which these fragments were autoclaved the acute inflammation was not as severe. In the cases in which the roots were planed and autoclaved, even less acute inflammation was seen in the 7-day specimens while some chronic inflammation persisted in the 21-day specimens. Implants from healthy roots evoked no response. The inflammation caused by the autoclaved diseased cementum was attributed to thermo-stable endotoxin. It was concluded that in advanced periodontal disease it is necessary to remove all of the cementum exposed to the pocket to eliminate its potential for inducing inflammation.

Adult↗
PubMed1987

The concentration of lipopolysaccharide on individual root surfaces at varying times following in vivo root planing.

Material with endotoxin activity has been detected in extracts prepared from pooled, periodontally involved teeth, and it has been shown that root planing in vivo reduces the level of such material. However, questions concerning the concentration of endotoxin on the diseased surfaces of individual teeth and questions concerning how rapidly individual root planed tooth surfaces retoxify in vivo have not been addressed previously. Citric acid extracts were prepared from individual, periodontally diseased teeth that had been extracted either from the oral cavity without prior root planing or at varying times up to 12 weeks following root planing. Using a chromogenic Limulus Amebocyte Lysate (LAL) assay, we were able to quantitate the amount of endotoxin associated with diseased root surfaces of individual teeth. We concluded that the extracted material contained endotoxin since it activated LAL and since the LAL-activation was heat-stable, acid-stable and neutralizeable by polymyxin B. The levels of endotoxin found on the root surfaces of these individual, periodontally involved teeth at varying times following in vivo root planing support the following conclusions: the concentration of endotoxin present on diseased root surfaces is markedly reduced, but not eliminated, by in vivo root planing, significant retoxification of root planed surfaces occurs within a relatively short time period after root planing and biological responses to such toxification conceivably may lead to subsequent phases having reduced levels of endotoxin.

Adult↗
PubMed2001

Dental unit waterline contamination and its possible implications during periodontal surgery.

BACKGROUND: Dental unit waterline contamination has become a concern to clinical dentistry. This concern arises from the fact that bacteria sloughed from established biofilms in dental unit waterlines increase heterotrophic bacteria counts in water exiting these units. METHODS: Scanning microscopy and bacterial viability staining were used to examine the sessile and planktonic biofilm present in dental unit waterlines and water samples, respectively. In addition, the limulus amebocyte assay was used to measure the lipopolysaccharide (LPS) levels in water samples. RESULTS: All dental unit waterlines were coated with a well-established biofilm made up of filamentous and bacillus-like microorganisms. Water samples collected from these dental units contained high numbers of individual bacteria and bacterial aggregates. A viability staining technique identified significantly more bacteria in water than could be cultured, and 64% of the total bacterial population stained as nonvital. Since the bacterial load (viable and nonviable) was high, we examined the LPS in dental unit water samples. The mean LPS levels in water collected from high-speed and air/water lines in use were 480 and 1,008 endotoxin units (EU)/ml. This was significantly higher than the mean level of 66 EU/ml found in water samples collected from adjacent clinic sinks. The LPS level at the start of the day (2,560 EU/ml) was reduced by 70% with 1 minute of flushing (800 EU/ml). Flushing times of 5 and 10 minutes were not able to reduce LPS levels to zero. CONCLUSION: The presence of high heterotrophic bacterial counts, sloughing biofilm, and high LPS levels are discussed in relation to patient risk and periodontal wound healing biology.

Analysis of Variance↗