Effects of parachlorophenol and camphorated parachlorophenol on the phagocytic activities of a murine macrophage cell line (RAW264.7)

Endodontic infection control practices among Pakistani general dental practitioners: A national cross-sectional questionnaire survey

Objective

This study was aimed at evaluating the self-reported endodontic infection control practices of general dental practitioners in Pakistan.

Methods

An e-questionnaire was sent to 619 general dental practitioners in several WhatsApp groups. Sixteen questions associated with various infection control measures recommended by the ESE were asked, including the use of various isolation methods/rubber dams, the selection of canal irrigants and anti-bacterial solutions, and practices regarding hand hygiene and use of examination gloves. The e-questionnaire also included questions associated with demographics. Data analysis was conducted in SPSS-24. Descriptive statistics were documented as percentages and frequencies.

Results

Of 619 GDPs, 350 responded (56.5% response rate), of whom 43.7% worked in private dental practices. The majority were women (64%), had graduated after 2010 (81.1%), and were 24-34 years of age (78.9%). A total of 72.3% of GDPs used cotton rolls, and 17.4% routinely used rubber dams for endodontic isolation; 89% did not disinfect the operative field; 80% reported using different concentrations of NaOCl during root canal instrumentation; and 0.9% reported not using any irrigant during endodontic procedures. A total of 61.7% reported always using intra-canal medication during multi visit endodontic treatment, among whom 82.5% reported using Ca(OH)2. Finally, 100% of respondents reported using gloves during endodontic treatment.

Conclusion

The results indicated that the GDPs tended to follow some of the endodontics quality standards recommended by the ESE, but the overall implementation of all guidelines requires improvement.

Role of protein kinase C in hydroxyapatite- induced phagocytosis by a murine macrophage cell line (RAW264.7)

The role of protein kinase C (PKC) in hydroxyapatite (HA)-induced phagocytosis by RAW 264.7 cells was investigated. The cells were incubated with HA particles at various incubation time and the levels of PKC activity were determined from the cell lysate. To determine the role of PKC, particles were incubated with the cells pretreated with the various concentrations of bisindolylmaleimide, a PKC inhibitor, and phagocytosis was then assessed at 60 min. Latex beads were used as a control. Our results showed that following incubation with HA particles, the levels of PKC activity in RAW264.7 cells was highest at 7 min and then decreased to reach the baseline levels of the controls at 30 min. Pretreatment of the cells with bisindolylmaleimide significantly reduced phagocytosis of HA particles in a dose-dependent pattern. The results of our present study suggest therefore that ingestion of HA by RAW264.7 cells may depend on PKC activity that may act in the early stages of phagocytosis.

Role of nitric oxide in hydroxyapatite-induced phagocytosis by murine macrophage cell line (RAW264.7)

The aim of this study was to determine the role of nitric oxide (NO) in hydroxyapatite (HA)-induced phagocytosis by a murine macrophage cell line (RAW264.7). The cells were incubated with HA particles at various incubation time and phagocytosis was assessed using phagocytic index (PI). NO production from the culture supernatants was determined by the Griess reagent. The inducible nitric oxide synthase (iNOS) expression was determined by Western blot. The particles were also incubated with cells pretreated with various concentrations of L-N(6)-(1-iminoethyl) lysine hydrochloride (L-NIL) or L-arginine. Latex beads were used as a control. Our results showed that macrophage phagocytosis induced by HA was higher than that induced by the beads. However, NO production by HA-stimulated cells was lower than that by bead-stimulated cells. iNOS expression in both bead- and HA-stimulated cells was observed expressed at 7, 15, 30, and 60 min. l-Arginine enhanced but l-NIL inhibited both phagocytosis and NO production by HA-stimulated cells. The results of the present study suggest that nitric oxide may play a crucial role in HA-induced phagocytosis by RAW264.7 cells.