[Assessment of validity of the archived standard curve in endotoxin assay, produced in other facilities].

We have reported the possibility of the use of the archived standard curve of endotoxin assay, which is prepared in the same facility from the viewpoint of the accuracy and precision. In this study, the possibility of the use of the archived standard curves prepared in the different facilities was investigated with the same data set in the previous paper. The evaluation was performed with the recovery rate of the concentrations of the standard solutions, as the same method as the previous study. The clotting times of the standard solutions were substituted into the standard curves prepared in the different facilities from those, in which standard solutions were prepared. The recovery rates were 86.1-125.0%, and the range was almost the same as that when the facility preparing standard solutions were the same as that preparing the standard curve. From this data, if the protocols of the preparation of standard solutions, such as mixing and the interval timing until set to the apparatus and so on, can be set the same between the endotoxin test and the preparation of the archived standard curves, the endotoxin concentration calculated with the archived standard curves prepared in other facilities were not varied very much, compared to the true values and the values obtained from the use of the archived standard curves prepared in the same facility.

Influência da irrigação ultrassônica passiva na redução de bactérias e endotoxinas dos canais radiculares: um estudo clínico randomizado / Influence of passive ultrasonic irrigation in bacteria and endotoxins from root canals: a randomized clinical study

Este estudo clínico analisou os efeitos dos procedimentos endodônticos e da irrigação ultrassônica passiva (PUI) em bactérias e endotoxinas de canais radiculares. Cinquenta pacientes com dentes com periodontite apical primária foram divididos de forma randomizada em dois grupos: PUI (n=25) e irrigação convencional (IC) (n=25). O preparo químico-cirúrgico (PQC) foi realizado com instrumentos reciprocantes, utilizando-se NaOCl 2,5% durante o preparo; e EDTA 17%, para remoção do magma dentinário. Os canais radiculares foram preenchidos com pasta de hidróxido de cálcio por 14 dias e obturados. Foram realizadas coletas microbiológicas dos canais antes (S1) e após o PQC (S2), após os protocolos de irrigação (S3), após a medicação intracanal (S4) e após a reinstrumentação dos canais (S5). Durante o processamento das amostras, as coletas de 5 casos foram perdidas por fatores diversos. As amostras foram analisadas por PCR quantitativo para detecção e quantificação de bactérias e pelo teste turbidimétrico de LAL para detecção e determinação do nível de endotoxinas. Bactérias e endotoxinas foram observadas em 100% das amostras iniciais coletadas. Em ambos os grupos, houve diminuição significativa na concentração de endotoxinas entre uma etapa do tratamento e a etapa posterior (p<0,05). O mesmo foi observado quanto ao número de bactérias, exceto entre a remoção da medicação intracanal e a reinstrumentação antes da obturação (S5). A análise intergrupos demonstrou que, com relação às endotoxinas, não foram observadas diferenças significativas entre os grupos (p>0,05)...

The aim of this clinical study was to compare the effects of passive ultrasonic irrigation (PUI) and intracanal medication with calcium hydroxide in bacteria and endotoxins from root canal. Fifty teeth with apical periodontitis were randomly divided into two groups according to the irrigation protocol: PUI (n = 25) and conventional irrigation (CI) (n = 25). The root canal preparation of all the teeth was carried out with reciprocating files and 2.5% NaOCl during preparation; and 17% EDTA for smear layer removal. The root canals were medicated with calcium hydroxide for 14 days. Microbiological sampling were performed before (S1) and after the preparation (S2) after irrigation protocols (S3), and after intracanal medication (S4 and S5). During the processing of the samples, five cases were lost for several factors. The samples were analyzed by real time PCR, for the detection and quantification of bacteria, and the turbidimetric LAL assay, for the detection and analysis of the endotoxin levels. Bacteria and endotoxins were observed in 100% of the initial samples. In both groups, there was a significant decrease in the concentration of endotoxins between one step and the subsequent step of treatment (p < 0.05). The same was observed for the number of bacteria, with the exception of the reinstrumentation after the removal of the medication (S5). The intergroup analysis showed no significant differences between groups in endotoxin reduction ( p > 0.05 ). PUI was able to reduce the number of bacteria significantly better than CI (p < 0.05). No significant statistical difference was observed between groups regarding the occurrence of cases wielding positive results for bacteria or endotoxin. It was concluded that PUI was more effective than CI in reducing the number of bacteria but not the amount of endotoxin in the root canal. Furthermore, each step of the endodontic therapy was effective in reducing both the number of bacteria as the amount of endotoxin...

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.

Biological activities of analogues of lipid A based chemically on the revised structural model. Comparison of mediator-inducing, immunomodulating and endotoxic activities.

Lipid A analogues were chemically synthesized based on the model structure recently revised, and biological activities of the analogues were tested. The analogue, (beta-1,6)-linked glucosamine disaccharide carrying ester-bound 3-hydroxytetradecanoic acids at 3 and 3' position of reducing and nonreducing glucosamine in addition to amide-bound 3-hydroxytetradecanoic acids and glycosidic-linked and ester-linked phosphate groups, showed much stronger activities for mediator inducing and immunomodulating as well as endotoxic activities than those exhibited by the previously synthesized analogues based on the old model. Among the activities tested, induction of interferon and tumor necrosis factor as well as mitogenicity, adjuvanticity and pyrogenicity were, however, not expressed so strongly as natural lipid A used as controls. In contrast, the analogue exhibited comparable activities to those of control lipid A in the test of lethal toxicity to mice and gelating activity of Limulus amebocyte lysate. Other synthetic analogues carrying a phosphate group showed comparable, slightly stronger or weaker activities depending on the test, but nonphosphorylated analogue exhibited no apparent or only very weak activities.