A Comparison of Pyrogen Detection Tests in the Quality Control of Meningococcal Conjugate Vaccines: The Applicability of the Monocyte Activation Test

The meningococcal C conjugate vaccine (MenCC) is an interesting model with which to test the efficacy of the Monocyte Activation Test (MAT) as an alternative method of pyrogen testing in the quality control of vaccines. The MenCC that has been produced by Bio-Manguinhos in Brazil is in the final development stage, and, as recommended in the guidelines for MenCC production, its pyrogen content must be determined by using the Limulus Amoebocyte Lysate (LAL) assay and the Rabbit Pyrogen Test (RPT). This represents an ideal opportunity to compare LAL and RPT data with data obtained by using a MAT system with cryopreserved whole blood and IL-6/IL-1β as marker readouts. In order to assess the compatibility of the MAT with MenCC, endotoxin and non-endotoxin pyrogen content was quantified by using MenCC samples spiked with lipopolysaccharide (LPS), lipoteichoic acid or zymosan standards. The presence of the aluminium-based adjuvant interfered with the MAT, increasing the readout of IL-1β in LPS-spiked MenCC batches. This infringed the product-specific validation criteria of the test, and led to IL-6 being chosen as the more suitable marker readout. No pyrogenic contaminants were identified in the MenCC batches tested, demonstrating consistency among the different systems (MAT, RPT and the LAL assay). In conclusion, the introduction of the MAT during MenCC development could contribute to the elimination of animal tests post-licensing, ensuring human protection based on an effective non-animal based method of quality control.

Role of insulin during the development of oligofructose (OF)-induced equine laminitis

Horses (n = 20) were divided into 2 groups: oligofructose (OF)-induced equine laminitis group (group OF; n = 11) which received 10 g/kg b.w. of OF dissolved in 4 L water via nasogastric intubation, and control group (NS; n = 9) which received 4 L of saline. Blood was collected at 4 h intervals over 72 h study period and analysed by ELISA, kinetic limulus amoebocyte lysate assay, and glucose-oxidase methods. The level of insulin changed significantly in horses which received OF (P < 0.01); there was a significant negative correlation between the level of adiponectin and insulin over time. The results suggested that insulin may play an important role in the development of OF-induced equine laminitis by altering the level of endothelin-1 and nitric oxide.

Application of Micro-kinetic Chromogenic Method in Endotoxin Quantitative Detection of Hydroxypropyl-β-cyclodextrin

The kinetic chromogenic assay with Limulus amoebocyte lysate to detect the bacterial endotoxin in Hydroxypropyl-β-cyclodextrin for injection is investigated in this paper. The test for interfering factors is performed to study the applicability of the kinetic chromogenic assay for detection of bacterial endotoxin in Hydroxypropyl-β-cyclodextrin for injection. The results suggest that r&gt;0.980 while the range is between 50-0.005EU/ml. Besides, when concentration of test solution is 1mg/ml for Hydroxypropyl-β-cyclodextrin, there is no interference between Limulus amebocyte lysate and bacterial endotoxin. The kinetic chromogenic assay can be used to detect the bacterial endotoxin in Hydroxypropyl- -β-cyclodextrin.

Detection of Endotoxin Concentration Using Piezoelectric Based Biosensor System

Endotoxins are ubiquitous in the environment and represent important pathogenic molecules. In this paper, we present a sensitive and reliable method for quantitation and detection of endotoxin based on piezoelectric biosensors, which monitor the gel formation (causing viscosity change) when Limulus Amoebocyte Lysate (LAL) mixed with endotoxin. The resonance frequency shifts of the sensors in contact with different concentration endotoxin were recorded as a function of time. Results showed that there has good relationship between the logarithmic concentration of endotoxin and the maximum clotting rate as well as the corresponding clotting time. The detection limits could be gone down to 0.1pg/ml and the time-consuming is about 1 hour using this system. By comparison of the traditional methods (rabbit pyrogen test and LAL test) for detection of endotoxin, the proposed sensor is much simpler, more precise and lower detection limits.