Successful and failed mini-implants: microbiological evaluation and quantification of bacterial endotoxin

Abstract Objectives Using two groups of mini-implants (successful and failed) the objectives of this in vivo study were: to evaluate the microbial contamination by the checkerboard DNA-DNA hybridization technique and to quantify the bacterial endotoxin by the limulus amebocyte lysate assay. Material and Methods The 15 successful and 10 failed mini-implants (1.6 mm diameter × 7.0 or 9.0 mm long), placed in the maxilla and/or mandible, were obtained from 15 patients undergoing orthodontic treatment. Data were analyzed statistically by the Wilcoxon rank-sum test using the SAS software (a=0.05). Results All 40 microbial species were detected in both groups of mini-implants, with different frequencies. No differences were observed between the groups with respect to microbial complexes (blue, purple, yellow, green, orange, red and other species) and endotoxin quantification (p>0.05). Conclusion Neither microbial contamination nor endotoxin quantification was determinant for the early loss of stability of the mini-implants.

Valoración de endotoxinas bacterianas en el inyectable ácido zoledrónico mediante la prueba de lisado del amebocito de Limulus / Assessment of bacterial endotoxins in Zoledronic acid injectable drug by using Limulus amebocyte lysate test

Objetivo: valorar las endotoxinas bacterianas por la técnica del lisado del amebocito de Limulus para el producto inyectable ácido zoledrónico, por el método de gelificación. Métodos: el ensayo se realizó mediante dos pruebas: 1) confirmación de la sensibilidad del lisado etiquetado, para lo cual se preparó una curva estándar con diluciones seriadas dobles de endotoxina por cuadruplicado; y 2) el ensayo del producto de inhibición, en el que se prepararon diluciones seriadas dobles de endotoxina con agua apirogénica y con las muestras de los lotes a ensayar sin sobrepasar la máxima dilución válida. Se determinó el punto final y se calculó la media geométrica. Se definió la dilución de trabajo, la cual se validó por cuadruplicado en tres lotes consecutivos. Resultados: la sensibilidad del lisado resultó 0,03125 UE/mL. La máxima dilución válida fue de 112 UE/mL y la dilución de trabajo 1/100. La cantidad de endotoxinas bacterianas presentes en tres lotes del producto inyectable no sobrepasó el límite establecido, por lo que cumplió con las especificaciones de calidad establecidas para el ensayo. Conclusión: la estandarización de las condiciones del método por gelificación, hace que este resulte eficaz, confiable, rápido y de fácil ejecución, por lo que puede emplearse como ensayo de rutina en el control de la calidad del inyectable analizado

Objective: To asses the presence of bacterial endotoxins in Zoledronic Acid injectable drug by using the Limulus amebocyte lysate test, particularly by the gelling procedure. Methods: The assay was performed in two tests: the first was the confirmation of labeled lysate sensitivity by preparing a standard curve with serial double dilutions of endotoxins four times, and the second was the inhibition product test in which serial double dilutions of endotoxins were prepared with apyrogenic water and with samples from the batches to be tested, without exceeding the maximum valid dilution. The end point was determined and the geometric mean was calculated. Working dilution was defined and then validated four times in three consecutive batches. Results: The lysate sensitivity was 0.03125 EU/mL). The maximum valid dilution and the working dilution were 112 EU/mL and 1/100 EU/mL) respectively. The amount of bacterial endotoxins present in three batches of the injectable drug did not exceed the set limit, so it complied with the quality specifications for this test. Conclusions: The standardization of the gelling method conditions makes it possible to state that this method is effective, reliable, quick and easy-to-perform, so it can be used as a regular test in the quality control of the analyzed parenteral drug

Application of limulus amebocyte lysate [LAL] test for detecting endotoxin [pyrogen] in large volume parenterals

Screening of twenty five large volume parenterals including dextrose, electrolytes, mannitol, metronidazole infusions, haemodialysis solution, water for injections and distilled water for the determination of pyrogen using Limulus Amebocyte Lysate [LAL] test has been carried out. Out of different preparations only one metronidazole injection exhibited positive LAL test, which was found pyrogen free with USP rabbit pyrogen test

Use of limulus amebocyte lysate assay in the diagnosis of gram-negative bacterial meningitis

CSF specimens were obtained from 32 infants and children suspected of having bacterial meningitis, CSF specimens were cultured and gram- stained for bacteria according to routine bacteriology procedures. Specimens were also evaluated for leukocytic count, glucose and protein concentrations. The presence of endotoxin was tested by the Limulus amebocyte assay. Bacteria were isolated from 17 patients, the infecting organisms were H. influenzae type [b] [8 cases], Neisseria meningitidis [6 cases], group [B] streptococcus [2 cases], and streptococcus pneumoniae [1 case]. Limulus lysate assay was positive in all the 14 patients with meningitis due to gram-negative bacteria, while it was consistently negative on specimens taken from patients with meningitis due to gram-positive organisms or from patients diagnosed as having no or aseptic meningitis