Subject(s)
Endotoxins/blood , Shock, Septic/blood , Adult , Aged , Bacterial Infections/blood , Female , Gram-Negative Bacteria , Humans , Limulus Test , Male , Middle AgedABSTRACT
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.
Subject(s)
Agranulocytosis/blood , Endotoxins/blood , Fever of Unknown Origin/etiology , Neutropenia/blood , Sepsis/microbiology , Adult , Female , Gram-Negative Bacteria/isolation & purification , Gram-Positive Bacteria/isolation & purification , Humans , Limulus Test , Male , Middle Aged , Neutropenia/microbiology , Prospective StudiesSubject(s)
Endotoxins/blood , Limulus Test , Shock, Septic/diagnosis , Adolescent , Adult , Aged , Chromogenic Compounds , Evaluation Studies as Topic , Female , Humans , Male , Middle Aged , Prognosis , Shock, Septic/mortalityABSTRACT
Four modes of heating endotoxin in plasma and two different times of heating endotoxin in pyrogen-free water were compared. There were no significant differences in standard curves after heating endotoxin in plasma at 100 degrees C for 1 and for 10 min. However, the standard curve after heating for 10 min at 75 degrees C had a significantly less steep slope, and after heating for 10 min at 56 degrees C, it was completely flat. Heating of endotoxin in pyrogen-free water for 1 min also resulted in the flattening of the standard curve, which was even more pronounced after 10 min of heating.
Subject(s)
Endotoxins/blood , Endotoxins/analysis , Escherichia coli , Hot Temperature , Humans , Limulus Test , Pyrogens , Time Factors , Water/analysisABSTRACT
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%.
Subject(s)
Endotoxins/analysis , Limulus Test/methods , Water/analysis , Aniline Compounds/metabolism , Chromogenic Compounds , Endotoxins/blood , Female , Humans , Ileum/surgery , Middle Aged , Postoperative Complications , Shock, Septic/blood , Shock, Septic/etiologyABSTRACT
A modified micromethod for endotoxin assay is reported which involved incubation of plasma extract with Limulus amoebocyte lysate for 30 min followed by incubation with chromogenic substrate S-2423 for another 8 min. Absorbance is measured in microtitre plates. The sensitivity is less than 5 pg/ml (0.058 Endotoxin Units/ml).
