Macrophages respond to bacterial lipopolysaccharides (LPS) and activate several host defense functions through production of mediators. However, it is not clear whether the degree of macrophage responsiveness to different sources of LPS is equivalent to or varies with the source of LPS. Therefore, in this report, we examined the extent of the human monocyte response to LPS derived from two oral pathogens, Actinobacillus actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg). Additionally, due to its well-established ability to activate monocytes, we used LPS from Escherichia coli (Ec). Human monocytes, when activated with a specific source of LPS, exhibited rapid expression of mRNA for IL-1 beta, TNF-alpha, and IL-8, which was followed by IL-6, as measured by RNA-PCR. Moreover, the expression of mRNA for these cytokines was followed by cytokine synthesis. Monocytes from the same subject, when activated with LPS from Pg, Aa, or Ec expressed quantitatively different levels of mRNA and proteins for all four cytokines. A given LPS induced either high or low expression of the battery of cytokines tested, indicating that the expression of these pro-inflammatory cytokines may be regulated by a single or a cluster of gene(s). However, no apparent differences in the time course of mRNA expression for these cytokines were observed in response to any of the LPS tested. Furthermore, the relative ability of the different sources of LPS to induce mRNA for cytokines varied throughout a wide range of LPS concentrations. This suggests that differences exist in the sensitivity of monocytes to a specific LPS, rather than in the kinetics of the secretory process itself.(ABSTRACT TRUNCATED AT 250 WORDS)
Decreased neutrophil chemotaxis has been implicated in the pathophysiology of the disease, localized juvenile periodontitis (LJP). The biological basis for the altered neutrophil function in LJP has been suggested to be an intrinsic cellular defect, involving a decrease in the number of N-formyl-methionyl-leucyl-phenylalanine (FMLP) receptors on the cell surface. We have investigated the relative contribution of serum-borne factors in the modulation of neutrophil functions in LJP, in a large population of LJP patients and healthy control subjects (HS). Treatment of HS-neutrophils with LJP-sera, resulted in a decreased neutrophil chemotactic response, and down regulation of FMLP receptors on the cell surface. Pretreatment of LJP-sera with anti-TNF and anti-IL-1 antibodies effectively, although incompletely, neutralized the ability of LJP-sera to modulate chemotaxis and FMLP receptor levels in HS-neutrophils. The changes induced by LJP sera were specific and sustained and could not be reversed by placing LJP-serum treated neutrophils in HS-serum. Sera obtained from HS and patients with adult periodontitis (AP), both of which exhibit normal chemotaxis, and patients with clinically diagnosed LJP with normal neutrophil chemotaxis (LJP-nctx) did not modulate HS neutrophil chemotaxis or FMLP receptors. Furthermore, recombinant human TNF-alpha, rhIL-1 alpha and rhIL-1 beta, at very low concentrations (15 pg/ml to 150 pg/ml), modulated the chemotactic response as well as FMLP receptor numbers on HS-neutrophils, in a manner similar to those observed in LJP. The present findings demonstrate that the biologic basis for the altered neutrophil function may not be an intrinsic cellular defect in neutrophils, but at least in part due to quantitatively small but biologically significant elevations in the levels of TNF-alpha and IL-1 in the serum.
Dental professionals have an opportunity to screen for substance use, provide targeted feedback based on patients' oral health, provide patient education, and refer for further assessment as needed. The aim of this study was to assess the impact on dental hygiene students of an interprofessional Screening, Brief Intervention, and Referral to Treatment (SBIRT) educational intervention with standardized patients as a tool for initiating discussions on alcohol and drug use with patients. Starting in 2015, dental hygiene students in two classes at the University of Pittsburgh participated with nursing students in one and a half hours of didactic instruction followed within a ten-week period by SBIRT simulation scenarios utilizing standardized patients, with subsequent debriefing of students by faculty. Students' attitudes were assessed before and after the didactic session and immediately after the SBIRT simulation, using the Alcohol and Alcohol Problems Perceptions Questionnaire and the Drug and Drug Problems Perceptions Questionnaire. All 67 dental hygiene students in the program at the time participated in the educational intervention and surveys. The results showed significant positive changes in role security, defined as the acceptance of SBIRT delivery as part of their role identity as dental hygienists, following the intervention. This study found that the IPE intervention with dental hygiene and nursing students improved the dental hygiene students' attitudes through using SBIRT.
Localized juvenile periodontitis (LJP) is an aggressive periodontal disease of familial nature. Neutrophils from a majority of patients with this disease exhibit decreased Chemotaxis with increased adherence, oxidative burst, and degranulation in response to opsonized bacteria. It is proposed that the biological basis for these altered neutrophil functions in LJP may be due either to intrinsic cell abnormalities or to the effect of factors present in the sera of LJP patients, which can modulate neutrophil functions. LJP neutrophils exhibit a lower number of receptors for chemoattractants and GP‐110 molecules which are known to facilitate Chemotaxis. Furthermore, these cells exhibit lower signal transduction in response to a biological stimulus. These observations suggest that intrinsic cellular defects may be responsible for altered neutrophil functions in LJP. However, healthy neutrophils, when treated with very low concentrations of proinflammatory cytokines, also exhibit the characteristics of altered or “defective” LJP neutrophils. Additionally, healthy neutrophils, when treated with LJP serum, also exhibit many of the characteristics associated with LJP neutrophils. Attempts to identify these factors have shown that cytokines like TNF‐α and/or IL1 β in LJP sera may be at least partially responsible for modulating neutrophil functions in LJP. These cytokines are primarily produced by activated macrophages, indicating a role for these cells in the etiology of LJP. The hyper‐responsiveness of these cells to an immunologic challenge can result in local increases in cytokines leading to excessive bone loss and tissue damage at the site of infection, while systemic elevations in cytokines would lead to decreased neutrophil Chemotaxis, both of which are observed in LJP. Present evidence indicates that neutrophil functions are indeed altered in the majority of LJP patients. However, the biological basis for the alteration may not be due to the neutrophils themselves but, rather, a consequence of an inherent hyperactive immune response during the host‐pathogen interaction. J Periodontol 1996;67:337–344.
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