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At least 19 recordsLinked to original sources
PubMed1975

[Pyrogen testing in vitro using the Limulus test].

The applicability of the Limulus test for the pyrogen test was checked in comparison to the pyrogen test in rabbits. In 6 out of 24 lots of raw materials and drugs pyrogens could be detected by means of the pyrogen test in rabbits. 2 of these 6 lots showed positive reaction in the Limulus test, there were no false positive results. Testing 7 bacterial strains in modified quantity of germs the Limulus test turned out to be more sensitive than the pyrogen test in rabbits. The application of this in vitro test as a complement to the pyrogen test in rabbits for a certain kind of problems is discussed.

Animals↗
PubMed1979

Determination of endotoxins in sugar with the Limulus test.

The Limulus amebocyte lysate test has been used for determination of pyrogens in sugar of different qualities. All the samples of domestic white sugar and beet raw sugar produced in Sweden during 1976 had a very low content of endotoxins, less than 10 ng/g of sugar. Imported cane raw sugar was, however, highly contaminated. The highest value obtained corresponds to about 100 mg of Escherichia coli endotoxin per g of raw sugar. Such crude sugar cannot, even after refining, be used for medical purposes. Instead, Swedish beet sugar is used as the raw material for production of invert sugar solutions for parenteral administration. The amount of endotoxin in this sugar is less than 1 ng/g.

Carbohydrates↗
PubMed1977

Detection of endotoxin in biological products by the limulus test.

The limulus amebocyte lysate (LAL) test is established as a beneficial quality assurance measure for the parenteral drug industry because of its sensitivity, specificity, and simplicity. Limulus amebocyte lysate reacts with various forms of endotoxin to form an opaque gel under acceptable conditions of pH, temperature, and ionic content. Although certain materials and conditions may alter the lysate-endotoxin reaction, the test is not significantly limited by inhibition or non-specific activation. Many U.S. drug firms apply the LAL test generally for monitoring production water and other ingredients, for an in-process control, and as a supplemental end product test for pyrogenic contamination. Specific applications are made for bacterial and viral vaccines, antineoplastic agents, radiopharmaceuticals and drugs designed for intrathecal injection. Efforts to standardize LAL test technique and lysate potency continue.

Animals↗
PubMed1976

Sensitivity of the Limulus test and inhibitory factors in the radiopharmaceuticals.

The basic sensitivity of the Limulus test and the inhibitory factors were examined in 21 radiopharmaceuticals commonly used in Japan. The sensitivity of the Limulus test using pre-gel was found to be 1 mug/ml for Escherichia coli endotoxin. This sensitivity is about ten times that of the rabbit test adopted by USP and JP. The Limulus test was applicable, with full sensitivity and without inhibitory reaction, for the evaluation of 99mTcO4-, 99mTc-albumin, 99mTc-MAA, 99,Tc-Sn-colloid, 131I-Hippuran, Na131I, Na251CrO49, 67Ga citrate, and 57Co-bleomycin as commercially supplied. On the other hand, with 111In-DTPA, 99mTc-phytate, 99mTc-pyrophosphate, 99mTc-DTPA, 131I-polyvinylpyrrolidone (PVP), 59FeCl3, Na232PO4, 198Au colloid, and selenomethionine (Se-75), the pH required adjustment to avoid inhibition of the gelation reaction. Benzyl alcohol showed an inhibitory effect on the gelation reaction at concentrations of more than 1%. Iodine-131-Bromsulphalein (BSP) and 131I-rose bengal showed intense inhibition of the gelation reaction.

Arthropods↗
PubMed1976

Measurement of endotoxin. II. Comparison of reactivities measured by radioimmunoassay and with the Limulus test.

Various endotoxins and the extracts of gram-positive bacteria were measured immunologically by radioimmunoassay and also biologically by the Limulus test. The minimum amount of endotoxin detectable with the Limulus test was in the range from 1ng/ml to 1 mug/ml, with the lysate of sensitivity, 100 ng/ml [E. coli O111: B4 (B) lipopolysaccharide]. On the other hand, by the radioimmunoassay they were estimated in the range o- 0.3 to 10 times of dry weight. Endotoxin-like activity was detected in the ether extracts of gram-positive bacteria at a minimum concentration between 1 mug/ml and 100 mug/ml with the Limulus test. However, most of them were estimated by the radioimmunoassay to be under 1/50 of dry weight. Various substances such as thrombin, thromboplastin, polyinosinic-polycytidylic acid, polyadenylic-polyuridylic acid, carrageenan and human colonic mucosal antigen had cross reactivities of various degrees in the minimum concentration from 10 mug/ml to 10 mg/ml. Compounds such as thrombin and thromboplastin cross-reacting in the Limulus test were scarcely measured by the radioimmunoassay except for polynucleotides. From this study, it has become clear that the radioimmunoassay method is quite specific and accurate for quantitative measurements of endotoxin.

Animals↗
PubMed1979

[Determination of endotoxemia by means of the Limulus test in patients with septicemia (author's transl)].

The Limulus test was applied to determine bacterial endotoxemia in 42 patients suspected of having septicemia. Hemocultures were practiced simultaneously. A comparative study is made of the two presently most commonly recommended tests for neutralizing the factors inhibiting the endotoxin-amebocyte reaction. According to our results the dilution of plasma in isotonic saline solution is preferable; we obtained a sensitivity of determination of 0.0001 micrograms of E. coli endotoxin per ml of plasm. Seventeen cases of bacteriemia were diagnosed, only one of which with sepsis due to Serratia marcescens responded positively to the limulus test. The test was positive in three of the remaining 25 patients. Two of them had liver failure. The basic role that liver failure plays in the high level of endotoxin in the blood is discussed. The prognostic value of this test and the low correlation between bacteremia and endotoxemia are also commented on

Endotoxins↗
PubMed1977

Studies on a simple Limulus test, a slide method.

A simple micromethod of Limulus test was studied. Briefly, this method is as follows. A 20 microliter aliquot of Pregel lysate solution and the same amount of sample are dropped on the same place on the silicone coated slide glasg and mixed well. Then it is incubated at 37 degrees C for 30 minutes in a moisture chamber. After the incubation, the vibration of the droplet surface is observed. When the vibration is no longer observed, it is judged as positive reaction, and when the vibration is still observed as before the incubation, it is judged as negative reaction. Compared with the conventional tube method, this method has advantages as below: 1) the judgement of the result is relatively objective, 2) shorter incubation period is enough for the reaction to take place and 3) smaller amount of Limulus lysate is enough for each sample. Besides these merits, the detection limit of this method is not inferior to that of the tube method.

Limulus Test↗
PubMed1979

Dry up method as a revised Limulus test with a new technique for gelatin inhibitor removing.

To detect endotoxins, Limulus test, especially its tube method, is recently used most widely. But this method has shortcomings considerably, for example, the lack of the objectivity on the judgement, the necessity of long handling time and the requirement of relatively large amount of Limulus lysate. To revise these shortcomings we established a new method. In our method, sample and Limulus lysate are mixed on a silicone coated slide glass and incubated at 37 degrees C for 30 min, then heated to dry up for the judgement. In samples which contain protein, the pretreatments with (NH4)2SO4, dilution and boiling are performed to remove gelation inhibitor. It was proved that this method could be applied to such samples as physiological saline, plasma, urine, transudate, exudate, cerebrospinal fluid (CSF) and suspension of Escherichia coli (E. coli). This method has advantages in its (1) objectivity of the judgement because of the clear difference of the dry up patterns between positive reaction and negative, (2) shortness of the handling time (results can be obtained within 2 hr from sampling), (3) requirement of little amount of sample and of Limulus lysate (a fifth volume of sample and a tenth volume of lysate are needed compared with the conventional method) and (4) sensitivity (0.1 or 0.5 ng/ml of lipopolysaccharide (LPS)).

Adult↗
PubMed1979

Measurement of endotoxins with the limulus test in burned patients.

High titres of endotoxin as measured by the Limulus test were usually found in burned patients who had raised body temperatures, and were colonized with gram-negative bacteria; also some infected patients showed raised endotoxin without a raised temperature. Patients vaccinated with an antipseudomonas vaccine rarely showed endotoxin in their plasma but occasional plasma samples from vaccinated patients had a high titre of endotoxin which appeared unrelated to infection or to a raised temperature in the patient.

Adolescent↗
PubMed1979

Calibration of the limulus test for blood products.

The Protein Fractionation Centre has been using the Limulus Amoebocyte Lysate test for detecting the presence of pyrogens for some five years. All tests on final plasma products have been carried out in parallel with the EP rabbit pyrogen test. Good correlation between both tests has been obtained with products such as distilled water and crystalloid solutions. However, it is more difficult to correlate results when dealing with plasma proteins. Each product appears to react differently. Some normally pass the limulus test undiluted while others, such as immune globulins and albuminoid products, have to be diluted to various concentrations before they pass. A preliminary statistical analysis has been carried out on the results of pyrogen testing on Stable Plasma Protein Solution, firstly to ascertain that a significant correlation does exist between the LAL test and the rabbit test, and secondly to try to obtain "cut off" values for the limulus test which compare well with the official EP temperature rises in the rabbit test.

Animals↗
PubMed1977

[Limulus test in diagnosis of acute meningitis (author's transl)].

We tried to evaluate the utility of the Limulus Test in the diagnosis of acute meningitis. The study was made in 60 patients divided in three groups: Group A, formed by 37 children affected by purulent meningitis of known etiology; Group B, formed by 10 children affected by purulent meningitis of unknown etiology; Group C, formed by 13 children with viral meningitis. The results were compared with a control group (Group D), of 10 healthy children. The results correlated with the etiology, the cuantitative count of germs/ml. in C.S.F. and the clinical evolution. The results indicated that the Test is a rapid, simple and useful tool for the detection of endotoxin in the C.S.F. of purulent meningitis caused by Gram negative germs.

Acute Disease↗
PubMed1976

[Contribution of the "limulus test" to the diagnosis of endotoxemias and meningitis due to gram negative bacteria].

The "limulus test" may be used to detect the endotoxins of Gram negative organisms. Applied to the cerebrospinal fluid (79 specimens from 64 patients) it proved itself to be a very important contribution to the differential diagnosis of purulent meningitis (95% positive results, no false positives). However it can be used on the plasma only in patients with shock of suspected endotoxic origin.

Adult↗
PubMed1975

Detection of endotoxins with the Limulus test in burned and unburned mice infected with different species of gram-negative bacteria.

The Limulus test detected endotoxins in the plasma of burned and unburned mice infected with different species of gram-negative bacteria produced different amounts of endotoxin in the plasma of infected mice. Plasma from mice given lethal infections showed very high concentrations of endotoxin. Low concentrations of endotoxin in the plasma were tolerated by mice but high concentrations were invariably fatal. A polyvalent pseudomonas vaccine reduced endotoxin in the plasma of mice given lethal infections of Pseudomonas aeruginosa.

Administration, Topical↗
PubMed1976

Clinical experience in detecting endotoxemia with the limulus test in typhoid fever and other Salmonella infections.

Semiquantitative estimates of circulating endotoxin were performed by the limulus test in patients suffering from typhoid fever and other salmonelloses. The test was positive in a large number of cases. However, no clearcut correlation was found between existence of endotoxemia, as such, and pyrexia. A correlation with recent bacteremia was found for highest levels of endotoxin activity. In minor salmonelloses a striking prevalence of positive cases was observed in the age group under one year. These findings were discussed in relation to the diagnostic and pathogenetic facets of the problem.

Adolescent↗