Using the monocyte activation test as a stand-alone release test for medical devices

Monocyte activation tests (MAT) are widely available but rarely used in place of animal-based pyrogen tests for safety assessment of medical devices. To address this issue, the National Toxicology Program Interagency Center for the Eval­uation of Alternative Toxicological Methods and the PETA International Science Consortium Ltd. convened a workshop at the National Institutes of Health on September 18-19, 2018. Participants included representatives from MAT testing laboratories, medical device manufacturers, the U.S. Food and Drug Administration’s Center for Devices and Radio­logic Health (CDRH), the U.S. Pharmacopeia, the International Organization for Standardization, and experts in the development of MAT protocols. Discussions covered industry experiences with the MAT, remaining challenges, and how CDRH’s Medical Device Development Tools (MDDT) Program, which qualifies tools for use in evaluating medical devices to streamline device development and regulatory evaluation, could be a pathway to qualify the use of MAT in place of the rabbit pyrogen test and the limulus amebocyte lysate test for medical device testing. Workshop outcomes and fol­low-up activities are discussed.

To Study The Efficacy Of Reciprocating Single File System And Multifile Rotary Systems In Elimination Of Root Canal Bacteria And Endotoxins

AIM: To study the efficacy of reciprocating single file system and multifile rotary systems in elimination of root canal bacteria and endotoxins. MATERIAL AND METHOD: Forty permanent single rooted mandibular premolars with straight canals inoculated with Escherichia Coli suspension for 21 days were selected for the study. Teeth were randomly divided into four groups (n=10) according to instrumentation system: Grp. A–Reciproc (VDW); Grp. B–WaveOne (Dentsply Maillefer); Grp. C–MTwo (VDW); and Grp. D–K3( Sybron Endo); Bacterial and endotoxin samples were collected with a sterile paper point before instrumentation and after instrumentation. Culture methods estimated the colony-forming units (CFU) and the Limulus Amebocyte Lysate test was used for quantification of endotoxins. Results so obtained were calculated and statistically analysed. RESULT: Results at S1 concluded that bacteria and endotoxins were found in all of the investigated root canals. After instrumentation all systems were associated with the significant reduction of the bacterial load and endotoxins respectively: Grp. A– Reciproc (88.25% and 89.10%); Grp. B– WaveOne (83.53% and 80.59%); Grp. C– MTwo(79.41% and 75.84%) and Grp. D– K3 (67% and 74.4%). Statistically no difference was found amongst the instrumentation systems regarding bacteria and endotoxin elimination (P <0.05). CONCLUSION: The reciprocating single file, Reciproc and WaveOne were as effective as the multifile rotary systems for the eradication of bacteria and endotoxins from root canals.

Companions at a Distance: Technoscience, Blood, and the Horseshoe Crab

In this paper we present a particular history of Limulus polyphemus, the horseshoe crab, as a means of expanding on Haraway’s notion of companion species. Drawing on accounts of the horseshoe crab’s role, on the one hand, in work of the Serological Museum at Rutgers University that spanned the 1940s to the 1970s, and, on the other, in the development of the limulus amebocyte lysate test, we trace some of the complexities of human-limulus relations. These relations encompassed not only the horseshoe crab’s objectification (as a source of serum), but also the natural historical, the mythical, and the symbolic (in relation to its blue blood or its supposed status as a “living fossil”). We suggest that the horseshoe crab, and similarly alien or abjected species, can be valued as companion species if this concept is expanded beyond parameters such as intimacy, surprise, and “becoming-with” to include distanciation, wonder, and “becoming-because-of.”

The level of endotoxins in hemodialysis water and dialysate in Lithuanian hemodialysis centers

The composition and quality of the dialysis fluid play an important role in the modulation of dialysis-related complications. During hemodialysis, patient’s blood has a contact with dialysate through a semipermeable membrane. Bacterial endotoxins can pass through the membrane pores into the patient’s blood and cause a silent chronic microinflammation. The aim of this study was to determine the level of endotoxins in hemodialysis water and dialysate in Lithuanian hemodialysis centers. Dialysis water (n=50) and dialysate (n=50) were collected from 91% (n=50) of all hemodialysis centers. The presence of bacterial endotoxins was evaluated using a sensitive Limulus amebocyte lysate test, which detects intact lipopolysaccharides. The level of endotoxins was lower than 0.25 EU/mL in 43 (86%) dialysis water samples and in 46 (92%) dialysate samples, and complied with the recommendations of the European Pharmacopoeia and the European Best Practice Guidelines for pure dialysis fluid. The dialysate of 39 (78%) Lithuanian hemodialysis centers complied with the definition of an ultrapure dialysis fluid. The water and dialysate were of insufficient quality in 14% and in 8% of Lithuanian hemodialysis centers, respectively, and this could be improved by the establishment of routine investigation of endotoxins.