Antibiotic prescription patterns among US general dentists and periodontists

BACKGROUND

In the absence of a full spectrum of evidence-based guidelines for the appropriate use of antimicrobial agents, dentists, including periodontists, remain a highly frequent antibiotic prescribing group. With the goal of understanding antibiotic prescribing practices, the authors surveyed a convenience sample of dental practitioners and periodontists to identify differences between the 2 cohorts and assess the factors that affect prescribing practices.

METHODS

An institutional review board-approved 15-item survey was developed to capture antibiotic prescribing practices addressing the main research question, factors affecting systemic antibiotic prescription patterns, and prescription timing. The authors collaborated with the American Dental Association (ADA) and the American Academy of Periodontology (AAP) for survey dissemination. Responses were summarized using descriptive statistics. Multivariable models were developed to identify antibiotic prescription predictors.

RESULTS

Overall, 32.4% of the participants prescribed systemic antibiotics with scaling and root planing. When comparing the 2 groups, the authors found that 46.4% and 18.7% of the AAP and ADA members, respectively, prescribed systemic antibiotics with scaling and root planing (P = .0001). The authors found a significant difference between the AAP and ADA groups in prescription timing (P = .01). The multivariable model revealed that practitioner sex (P = .03), AAP membership (P = .0001), and years of practitioner experience (P = .04) predicted antibiotic prescription practices. The geographic location, practice setting, and occupation type did not predict antibiotic prescription patterns.

CONCLUSION

The authors found a lack of clarity related to prescription timing, factors determining prescription patterns, and selection of patient population who would benefit more from antibiotics.

PRACTICAL IMPLICATIONS

This study confirmed a lack of clarity related to antibiotic prescription patterns in combination with nonsurgical periodontal treatment.

"Epigenome-wide methylation profile of chronic kidney disease-derived arterial DNA uncovers novel pathways in disease-associated cardiovascular pathology."

Chronic kidney disease (CKD) related cardiovascular disease (CVD) is characterized by vascular remodelling with well-established structural and functional changes in the vascular wall such as arterial stiffness, matrix deposition, and calcification. These phenotypic changes resemble pathology seen in ageing, and are likely to be mediated by sustained alterations in gene expression, which may be caused by epigenetic changes such as tissue-specific DNA methylation. We aimed to investigate tissue specific changes in DNA methylation that occur in CKD-related CVD. Genome-wide DNA methylation changes were examined in bisulphite converted genomic DNA isolated from the vascular media of CKD and healthy arteries. Methylation-specific PCR was used to validate the array data, and the association between DNA methylation and gene and protein expression was examined. The DNA methylation age was compared to the chronological age in both cases and controls. Three hundred and nineteen differentially methylated regions (DMR) were identified spread across the genome. Pathway analysis revealed that DMRs associated with genes were involved in embryonic and vascular development, and signalling pathways such as TGFβ and FGF. Expression of top differentially methylated gene HOXA5 showed a significant negative correlation with DNA methylation. Interestingly, DNA methylation age and chronological age were highly correlated, but there was no evidence of accelerated age-related DNA methylation in the arteries of CKD patients. In conclusion, we demonstrated that differential DNA methylation in the arterial tissue of CKD patients represents a potential mediator of arterial pathology and may be used to uncover novel pathways in the genesis of CKD-associated complications.

Gingival Thickness and Outcome of Periodontal Plastic Surgery Procedures: A Meta-regression Analysis

OBJECTIVE

To evaluate the impact of soft tissue thickness (STT) on root coverage achieved with different periodontal plastic surgery procedures.

BACKGROUND

Gingival recession has been managed successfully through various surgical approaches, with great variability in outcomes. Anatomic characteristics of the recipient site and selected technique account in part for this variability. Gingival flap thickness is one of the most critical site-related characteristics.

METHODS

An electronic search was conducted on the major databases (PubMed, Embase, Web of Science). Human prospective studies with at least 6 mo of follow-up and with a numeric baseline measurement for gingival thickness were eligible. Only studies including nonsmoking patients were considered. Variables included surgical approach, participant characteristics, local anatomic factors, and follow-up time. Primary outcome was mean percentage root coverage (%RC) achieved, and complete root coverage was a secondary outcome.

RESULTS

A total of 42 studies were included (35 randomized controlled trials, 5 case series, 1 prospective cohort study, and 1 controlled clinical trial). Across studies, the pooled %RC was 81.9% (95% CI, 79.1% to 84.7%). The %RC was not significantly associated (P = 0.267) with baseline soft tissue thickness; however there was a significant (P = 0.031) inverse relationship between STT and %RC after 12-mo follow-up. Subgroup analysis showed that for no graft, there was a significant (P = 0.025) positive relationship between STT and %RC with the exclusion of the single outlier study based on STT.

CONCLUSIONS

STT plays a limited role in predicting root coverage across all approaches; when flaps are performed with no graft, the effect of STT is most critical. The length of time following surgery appears to influence outcomes, with 12-mo follow-up offering greater insight.

KNOWLEDGE TRANSFER STATEMENT

The results of this study can suggest to clinicians which periodontal plastic surgery technique to employ when treating challenging cases. In particular, it can be helpful when selecting the treatment approach to treat thin phenotype sites. This study could help clinicians provide a more appropriate treatment decision in such cases.

The Evolution of the Journal Club: From Osler to Twitter

Journal clubs have typically been held within the walls of academic institutions and in medicine have served the dual purpose of fostering critical appraisal of literature and disseminating new findings. In the last decade and especially the last few years, online and virtual journal clubs have been started and are flourishing, especially those harnessing the advantages of social media tools and customs. This article reviews the history and recent innovations of journal clubs. In addition, the authors describe their experience developing and implementing NephJC, an online nephrology journal club conducted on Twitter.

Impression Techniques Used for Single-Unit Crowns: Findings from the National Dental Practice-Based Research Network

PURPOSE

To: (1) determine which impression and gingival displacement techniques practitioners use for single-unit crowns on natural teeth; and (2) test whether certain dentist and practice characteristics are significantly associated with the use of these techniques.

MATERIALS AND METHODS

Dentists participating in the National Dental Practice-Based Research Network were eligible for this survey study. The study used a questionnaire developed by clinicians, statisticians, laboratory technicians, and survey experts. The questionnaire was pretested via cognitive interviewing with a regionally diverse group of practitioners. The survey included questions regarding gingival displacement and impression techniques. Survey responses were compared by dentist and practice characteristics using ANOVA.

RESULTS

The response rate was 1777 of 2132 eligible dentists (83%). Regarding gingival displacement, most clinicians reported using either a single cord (35%) or dual cord (35%) technique. About 16% of respondents preferred an injectable retraction technique. For making impressions, the most frequently used techniques and materials are: poly(vinyl siloxane), 77%; polyether, 12%; optical/digital, 9%. A dental auxiliary or assistant made the final impression 2% of the time. Regarding dual-arch impression trays, 23% of practitioners report they typically use a metal frame tray, 60% use a plastic frame, and 16% do not use a dual-arch tray. Clinicians using optical impression techniques were more likely to be private practice owners or associates.

CONCLUSIONS

This study documents current techniques for gingival displacement and making impressions for crowns. Certain dentist and practice characteristics are significantly associated with these techniques.

Changes in diabetes medications in the Diabetes and Periodontal Therapy Trial and their effect on hemoglobin A1c (HbA1c)

OBJECTIVE

Evaluate the effect of medications and medication changes during the Diabetes and Periodontal Therapy Trial (DPTT) on the primary study outcome, namely, change in hemoglobin A1c (HbA1c) at 6months following baseline.

METHODS

The DPTT set strict criteria for changes in diabetes medications. Medication change was defined as: change in dose of any 1 oral hypoglycemic agent by more than two-fold, change in dose of insulin of >10% and/or addition or subtraction of an oral hypoglycemic agent, insulin or non-insulin injectable agents. Comparisons between the treatment (non- surgical periodontal therapy) and control (no therapy) groups used t-tests for continuous variables and chi-square tests for categorical variables, including DPTT defined diabetes medication changes between baseline (BL) and 3month visits and 3- and 6-month visits. Changes in HbA1c were compared across the four medication change categories using ANOVA models, overall and for each treatment group separately.

RESULTS

Baseline medication use was similar between the treatment groups (p>0.40), as were medication changes between BL- 3month visits and 3 and 6month visits (p=0.58). Participants with higher BL HbA1c (>8%) and those taking insulin at BL were more likely to have a change in medication (p=0.03).

CONCLUSIONS

The DPTT had the most rigorous definition of medication changes and medication monitoring of any trial in this field to date. The absence of a significant difference in medication changes between treatment groups may suggest that such changes did not play a role in the negative outcome of the DPTT.

Connecting and Collaborating: Developing National Dental PBRN Study Concepts Through POD Engagement

PURPOSE

This article illustrates the process by which the Southwest Region of the National Dental Practice-Based Research Network (www.NationalDentalPBRN.org) fosters collaboration among practitioners and researchers in study concept development through protocol development groups (PODs). The Southwest Region begins this process by engaging PODs, which comprise dentists, hygienists, and/or academic faculty who share research interests related to improving dental care.

METHOD

The PODs use the Tuckman four-stage model of group development (forming, storming, norming, and performing) to develop study concepts. This well-structured model encourages engagement among group members and enables quality discussion through organized sessions. This model provides milestones for the group's progression and for the members' interactions. The Southwest Region Directors play a crucial role in guiding and directing the development of PODs by aligning the members' research interests with the goals of the National Network.

RESULTS

POD engagement using Tuckman's stages has been successful in developing study concepts for submission to the National Network. Between 2012 and 2014, the Southwest Region has developed 14 PODs from 275 research ideas. Five of these study concepts have been submitted to the National Network for approval, including the Novel Tobacco Products POD, which showcases the applicability of Tuckman's model.

CONCLUSION

Overall, the POD concept is a collaborative effort that brings together practitioners and academicians through shared research interests and capitalizes on participants' expertise and experiences. The Southwest Region will continue to develop PODs to foster new ideas for future studies in the Network.

Generating National Dental PBRN Research Ideas Through the ToP Consensus Method Workshop

PURPOSE

The purpose of this article is to illustrate the research idea generation process employed by the Southwest Region of the National Dental Practice-Based Research Network (PBRN; www.NationalDentalPBRN.org) based on the Technology of Participation (ToP) Consensus Method Workshop. This method encourages a high level of participation in the decision-making process through individual, small group, and large group discussions. This approach to idea generation has predominately been used by nonprofit organizations and community groups both nationally and internationally, but offers great potential to study concept development for PBRNs.

METHOD

Five independent workshops were designed over a 12-month period. Workshops were held at three academic institutions, one National Dental PBRN meeting, and one as part of a continuing education program. The sessions were directed at general dentists, dental hygienists, and dental researchers to identify research ideas appropriate for examination through the PBRN mechanism.

RESULT

Five groups ranging in size from 11 to 53 (197 participants total) participated in the consensus workshops and generated 205 research ideas. Ideas across the five sessions were collated into novel and common categories of interest, and identified key participants interested in developing research concepts. Participant reaction to the sessions was positive based on evaluation comments and personal interactions.

IMPLICATIONS

Practitioners effectively generated research ideas based on their current needs and daily clinical experience. The experiences presented in this article suggest continued use of the ToP consensus workshop methods within the PBRNs may help bridge the gap between research and practice.

Review of osteoimmunology and the host response in endodontic and periodontal lesions

Both lesions of endodontic origin and periodontal diseases involve the host response to bacteria and the formation of osteolytic lesions. Important for both is the upregulation of inflammatory cytokines that initiate and sustain the inflammatory response. Also important are chemokines that induce recruitment of leukocyte subsets and bone-resorptive factors that are largely produced by recruited inflammatory cells. However, there are differences also. Lesions of endodontic origin pose a particular challenge since that bacteria persist in a protected reservoir that is not readily accessible to the immune defenses. Thus, experiments in which the host response is inhibited in endodontic lesions tend to aggravate the formation of osteolytic lesions. In contrast, bacteria that invade the periodontium appear to be less problematic so that blocking arms of the host response tend to reduce the disease process. Interestingly, both lesions of endodontic origin and periodontitis exhibit inflammation that appears to inhibit bone formation. In periodontitis, the spatial location of the inflammation is likely to be important so that a host response that is restricted to a subepithelial space is associated with gingivitis, while a host response closer to bone is linked to bone resorption and periodontitis. However, the persistence of inflammation is also thought to be important in periodontitis since inflammation present during coupled bone formation may limit the capacity to repair the resorbed bone.

Haemodiafiltration versus high-flux haemodialysis: Effects on phosphate control and erythropoietin response

INTRODUCTION

Haemodiafiltration (HDF) has been reported to improve erythropoietin (EPO) responsiveness and phosphate clearance. We prospectively audited the effect of HDF on EPO dosages, weight and serum phosphate.

METHODS

34 patients dialyzing on Tu/Th/Sa switched to HDF, and 44 dialyzing on M/W/F remained on high-flux haemodialysis (HD) and were followed for 12 months.

RESULTS

Dialysis adequacy (Kt/V start HDF 1.56 ± 0.03 vs. HD 1.58 ± 0.04 and 12 months 1.55 ± 0.03 vs. 1.59 ± 0.03), haemoglobin (start 11.7 ± 0.3 vs. 11,8 ± 0.2 g/dl and end 11.5 ± 0.1 vs. 11.3 ± 0.3 g/dl), weight (start 69.8 ± 2.4 vs. 67.8 ± 2.5 kg and end 67.4 ± 2.5 vs. 66.1 ± 2.3 kg), or EPO prescription (start 83 (61-186) vs. 123 (71-225) IU/kg/weeks and 12 months 142 (48-188) vs. 124 (59-223) IU/kg/weeks) did not differ. There were no differences in serum albumin, CRP, calcium and parathyroid hormone. Serum beta-2-microglobulin (B₂M) decreased with HDF (32.7 ± 1.9 vs. 28.1 ± 1.1 mg/l, p < 0.01), but not with HD (31.6 ± 1.4 vs. 31.5 ± 1.1 mg/l). Serum phosphate fell with HDF (start 1.48 ± 0.08 vs. 1.57 ± 0.07 mmol/l (p = NS); 3 months 1.35 ± 0.07 vs. 1.61 ± 0.08; 6 months 1.34 ± 0.06 vs. 1.57 ± 0.06, and 12 months 1.36 ± 0.07 vs. 1.67 ± 0.07, all p < 0.05).

CONCLUSION

HDF did not lead to weight gain or improved EPO responsiveness in this prospective observational study. However, predialysis serum phosphate and B₂M fell with HDF.

A prospective randomized clinical study of changes in soft tissue position following immediate and delayed implant placement

PURPOSE

The purpose of this investigation was to compare the efficacy of two therapeutic options-immediate implant placement and ridge preservation with delayed implant placement-in maintaining the position of the soft tissue margins following tooth extraction.

MATERIALS AND METHODS

This randomized controlled study evaluated apicocoronal changes in the midbuccal and proximal mucosal positions at implant placement sites from tooth extraction to 3 and 6 months following extraction. Twenty-four patients (26 sites) randomly received either immediate implant placement or ridge preservation (grafting with freeze-dried bone allograft and a collagen membrane) followed by implant placement 3 months later. Immediate placement sites received bone grafting for horizontal defects > 2 mm (from implant to cortical wall). Soft tissue measurements, vertical measurements, and ridge width measurements were performed and compared for immediate versus delayed implants and thin versus thick biotype.

RESULTS

The midbuccal soft tissue margins showed minimal recession over 6 months from the time of extraction (mean 0.17 +/- 0.47 mm), with no differences between treatment groups. Interproximal tissue height decreased significantly from extraction to 6 months (mesial, 1.73 +/- 0.71 mm; distal, 1.48 +/- 0.80 mm), with no significant differences between immediate and delayed placement. Immediate implant sites had greater reductions in ridge width 6 months after extraction than delayed placement sites. Tissue biotype failed to show any significant relationship with the changes identified.

CONCLUSIONS

This randomized controlled study comparing soft tissue changes following extraction failed to identify differences between patients treated with immediate or delayed approaches for midbuccal or interproximal soft tissue margins, although greater decreases in ridge width were observed in sites lacking bone grafting. Both immediate and delayed treatment approaches appear to be appropriate following tooth extraction, with the preferred treatment based on factors other than resultant soft tissue changes.

Inflammatory biomarkers in airways of patients with severe asthma compared with non-severe asthma

BACKGROUND

About 5-10% of patients with asthma suffer from poorly-controlled disease despite corticosteroid (CS) therapy.

OBJECTIVE

We determined whether there were any differences in inflammatory biomarkers between severe and non-severe asthma patients.

METHODS

Nineteen severe and 20 non-severe asthma patients were recruited and underwent collection of induced sputum, bronchoalveolar lavage (BAL) fluid and bronchial biopsies.

RESULTS

Biopsy results showed no differences in eosinophils (major basic protein positive), neutrophils, macrophages, T cells and mast cells in the bronchial submucosa. However, subbasement membrane (SBM) thickness and smooth muscle area were increased in the biopsies. No significant differences were observed in the induced sputum inflammatory cells. In BAL fluid, there was a significant increase in neutrophils but a significant decrease in macrophages. Eosinophil counts were non-significantly increased threefold in both sputum and BAL in severe asthma. Levels of IL-8 and IL-13 in sputum supernatants were similar in both groups of asthma patients. There was a significant inverse correlation between post-bronchodilator forced expiratory volume in 1 s and provocative concentration of methacholine causing a 20% fall in FEV(1) with SBM thickness.

CONCLUSION

Differences in inflammatory cells were observed mainly in terms of increased neutrophils and reduction in macrophage numbers in BAL fluid with a trend towards increased eosinophils in severe asthma compared with non-severe asthma. However, the most notable features are the increase in features of airway wall remodelling of SBM thickness and smooth muscle area.

Clinical Field Trial Examining an Implant With a Sand-Blasted, Acid-Etched Surface

BACKGROUND

Conventionally, endosseous dental implants have required 3 to 6 months of uninterrupted healing based on observations for dental implants that were characterized by a relatively smooth machined surface. Many studies have since demonstrated that implants with a roughened surface resulted in greater bone apposition, earlier bone contact, and a stronger bond between the implant and the bone, suggesting that implants with roughened surfaces could be loaded earlier than 3 to 6 months. Formal clinical studies confirmed that implants with rough surfaces can have abutments placed and be loaded occlusally as early as 6 weeks postplacement. The purpose of this prospective, human clinical investigation was to evaluate a large number of implants with a specific rough surface (sand-blasted acid-etched [SLA]) placed in everyday practice under routine private-practice conditions.

METHODS

A prospective, multicenter, human clinical observational study was initiated with the goal of recruiting a minimum of 500 patients and 800 implants. The implants were to be placed and restored in predominantly private-practice settings around the world. Ninety-two practitioners in 16 countries agreed to participate, and 86 followed the study design. Patients had to be in good health, have sufficient bone to encase the implant, and agree to return for recall appointments. Exclusion criteria included heavy smoking (>10 cigarettes a day) and bone augmentation procedures at the implant site. All implants were two-piece (an abutment was to be placed after 6 weeks of healing) and were characterized by the presence of a transmucosal polished collar. Each implant had an SLA surface. All implants were positioned using a non-submerged (single-stage) surgical technique. Survival and success rates were calculated by life-table analyses.

RESULTS

A total of 706 patients were enrolled and 1,406 implants were placed. In the final analyses, 590 patients with 990 implants (70.4% of those enrolled) met all inclusion criteria, including placement of an abutment and provisional restoration within 63 days of surgical placement. The majority of implants were 10 and 12 mm long (78.7%) and were placed in type II and III bone (87%). Seventy-three percent of the implants were placed in the mandible, and 27% were placed in the maxilla. The cumulative survival rate was 99.56% at 3 years and 99.26% at 5 years. The overall success rate was 99.12% at 3 years and 97.38% after 5 years.

CONCLUSIONS

Under private-practice conditions, implants with an SLA surface could be placed and restored predictably within 6 to 8 weeks. Data from this prospective, multicenter, human observational study reinforced the results of more formal clinical studies and demonstrated that implants with the SLA surface can be restored in patients in approximately half of the time of conventional healing periods.

Human Periodontal Fibroblast Response to Enamel Matrix Derivative, Amelogenin, and Platelet-Derived Growth Factor-BB

BACKGROUND

The ideal goal of clinical therapy in periodontal defects is regeneration of all lost structures. For regeneration to occur, cell proliferation, migration, and extracellular matrix synthesis are prerequisites. Attempts at regeneration of periodontal defects by guided tissue regeneration using bone grafts and membranes have not always yielded predictable results. Recently, attempts at engineering the defects using various materials have shown promising results. Two such approaches have been used to regenerate periodontal defects, one using extracellular matrix such as enamel matrix proteins and the other using growth factors. However, to our knowledge, no study has looked at combining these two approaches to achieve potentially even greater regeneration.

METHODS

Primary human periodontal ligament (PDL) fibroblasts were explanted, and alkaline phosphatase (ALK PHOS) activity was determined. Phenotypically different cell lines were incubated for 1, 3, 6, and 10 days in 0.2% fetal bovine serum (FBS) media containing different concentrations of either enamel matrix derivative (EMD), amelogenin, platelet-derived growth factor-BB (PDGF-BB), EMD+PDGF-BB, or amelogenin+PDGF-BB. A culture of 0.2% FBS alone served as a negative control, and a culture of 10% FBS served as a positive control. Cell proliferation was measured using a Coulter counter to determine the cell number. The effects on a wound-fill model were evaluated by scraping a 3-mm wide cell-free zone in PDL monolayers across the diameter of the tissue-culture plate and determining PDL cell migration into the cell-free zone using computer assisted histomorphometry.

RESULTS

Compared to the control, only EMD+PDGF-BB significantly increased PDL cell proliferation in an ALK PHOS (-) cell line (P<0.001), and EMD alone, EMD+PDGF-BB, and amelogenin+PDGF-BB significantly increased PDL cell proliferation in an ALK PHOS (+) cell line (P<0.001) with EMD+PDGF-BB showing a trend for greater proliferation than either PDGF or EMD alone. Individually, EMD and amelogenin had no significant effect on PDL cell proliferation. In the wound-fill experiment, all factors and their combinations except amelogenin significantly enhanced cell migration compared to the control (P<0.05) at the wound edge. In addition, EMD+PDGF-BB had additive effects on the ALK PHOS (-) cell line at the wound edge. At the center of the wound, neither EMD nor amelogenin had a significant wound-fill effect. However, the combination of EMD+PDGF-BB additively increased wound fill for both ALK PHOS (+) and ALK PHOS (-) cells.

CONCLUSIONS

The combination of EMD and PDGF-BB produces greater proliferative and wound-fill effects on PDL cells than each by themselves. If these combined effects can be translated clinically, one may see greater regeneration in periodontal defects with this combination. However, amelogenin does not have significant effects on PDL cell proliferation or migration by itself. This may suggest that either another enamel matrix component in EMD may be responsible for some of its clinical effects, or that amelogenin alone may not trigger the regenerative potential of periodontal tissues and that it requires a combined interaction with other enamel matrix components of EMD to direct the regenerative process.

STAT4 activation in smokers and patients with chronic obstructive pulmonary disease

Activation of the transcription factor signal transducer and activator of transcription (STAT)-4 is critical for the differentiation of T-helper 1 cells/type-1 cytotoxic T-cells and the production of interferon (IFN)-gamma. Expression of STAT4, phospho-STAT4, IFN-gamma and T-box expressed in T-cells (T-bet) proteins in bronchial biopsies and bronchoalveolar lavage (BAL)-derived lymphocytes, obtained from 12 smokers with mild/moderate chronic obstructive pulmonary disease (COPD) (forced expiratory volume in one second (FEV1) 59 +/- 16% predicted), 14 smokers with normal lung function (FEV1 106 +/- 12% pred) and 12 nonsmoking subjects (FEV1 111 +/- 14% pred), was examined by immunohistochemistry and immunocytochemistry. In bronchial biopsies of COPD patients, the number of submucosal phospho-STAT4+ cells was increased (240 (22-406) versus 125 (0-492) versus 29 (0-511) cells mm(-2)) when compared with both healthy smokers and control nonsmokers, respectively. In smokers, phospho-STAT4+ cells correlated with the degree of airflow obstruction and the number of IFN-gamma+ cells. Similar results were seen in BAL (2.8 (0.2-5.9) versus 1.03 (0.09-1.6) versus 0.69 (0-2.3) lymphocytes x mL(-1) x 10(3)). In all smokers who underwent lavage, phospho-STAT4+ lymphocytes correlated with airflow obstruction and the number of IFNgamma+ lymphocytes. T-bet expression was not altered in bronchial biopsies and BAL-derived lymphocytes between the three groups. In conclusion, this study suggests that stable mild/moderate chronic obstructive pulmonary disease is associated with an active T-helper 1 cell/type-1 cytotoxic T-cell inflammatory process involving activation of signal transducer and activator of transcription 4 and interferon-gamma production.

Differential expression of IL-10 receptor by epithelial cells and alveolar macrophages

BACKGROUND

Interleukin (IL)-10 is a pleiotropic cytokine with a broad spectrum of immunosuppressive and anti-inflammatory effects. IL-10 secretion from alveolar macrophages is defective in patients with asthma and lower concentrations of IL-10 are found in bronchoalveolar lavage (BAL) from asthmatic patients than in normal control subjects. Reduced IL-10 may result in exaggerated and more prolonged inflammatory responses in asthmatic airways. IL-10 acting through the IL-10 receptor (IL-10R) stimulates the transcription factors STAT1 and STAT3.

METHODS

We investigated IL-10 and IL-10R expression in normal and asthmatic bronchial epithelium and BAL macrophages using reverse transcription-polymerase chain reaction, immunohistochemistry and Western blotting. The functional effect of IL-10 was examined using granulocyte-macrophage-colony stimulating factor, enzyme-linked immunosorbent assay and Western blotting for phosphorylated STAT1 and STAT3.

RESULTS

IL-10 was not expressed in epithelial cells; furthermore these cells did not express the IL-10R and had no functional response to exogenous IL-10. Bronchial epithelial cells expressed variable levels of phosphorylated STAT1 and STAT3 with no change in expression between normal subjects and asthmatics. IL-10 protein and IL-10R expression was detected in alveolar macrophages from all subjects.

CONCLUSION

Our study suggests that the bronchial epithelium is not a source of IL-10 and cannot respond to exogenous IL-10 because of a lack of IL-10R expression.

Increased expression of nuclear factor-kappaB in bronchial biopsies from smokers and patients with COPD

The expression of nuclear factor (NF)-kappaB is an indicator of cellular activation and of inflammatory mediator production. The aim of the present study was to characterise the expression and localisation of p65, the major subunit of NF-kappaB, in the bronchial mucosa of patients with chronic obstructive pulmonary disease (COPD), and to examine the relationship between p65 expression and disease status. Bronchial biopsies were obtained from 14 smokers with COPD, 17 smokers with normal lung function and 12 nonsmokers with normal lung function. The number of p65 positive (+) cells was quantified by immunohistochemistry and the expression of p65 in bronchial biopsies from the three groups was examined by Western blotting (WB). Smokers with normal lung function and patients with COPD had increased numbers of p65+ cells in the epithelium and increased p65 nuclear expression. In COPD patients the number of epithelial p65+ cells correlated with the degree of airflow limitation. WB analysis showed an increase in p65 in smokers with normal lung function and COPD patients (p<0.05). Bronchial biopsies in smokers with normal lung function and chronic obstructive pulmonary disease patients show increased expression of p65 protein, predominantly in the bronchial epithelium. Disease severity is associated with an increased epithelial expression of nuclear factor-kappaB.

Expression of respiratory mucins in fatal status asthmaticus and mild asthma

AIMS

The airways of patients with asthma are characterized by chronic inflammatory changes comprising mainly T-cells and eosinophils, and airway remodelling with goblet cell metaplasia and submucosal gland hyperplasia. Mucus hypersecretion is often a marked feature, particularly in status asthmaticus. The matrix of airway sputum consists of high molecular glycoproteins and mucins. In this study, the expression and distribution of the major gel-forming mucins MUC5AC and MUC5B were studied in fatal status asthmaticus tissues and bronchial biopsies of mild asthmatic patients. The effect of inhaled corticosteroids on the expression of these mucins was also investigated.

METHODS AND RESULTS

Polyclonal antibodies specific for MUC5AC and MUC5B, and a monoclonal antibody for MUC5B were used to stain lung tissues and airway mucosal biopsies obtained from patients who died of status asthmaticus (n=5) and from mild asthmatics (n=4), respectively. Immunohistochemistry for MUC5AC revealed abundant staining of goblet cells situated in the epithelial surface lining and glandular ducts of tissues from patients with fatal asthma. MUC5B immunoreactivity was restricted to mucous cells of submucosal glands and to epithelial cells. In mild asthmatics, large amounts of MUC5B, but not MUC5AC, positive extracellular mucus was found in the airway lumen as plugs, adjacent to the epithelial lining and in the necks of glandular secretory ducts of mild asthmatics. The distribution of MUC5AC and MUC5B in bronchial biopsies of mild asthmatics was similar before and after inhaled steroid treatment.

CONCLUSIONS

The expression of MUC5AC and MUC5B shares a similar distribution to normal airways in different states of asthma. The distribution is not affected by topical corticosteroid therapy.

Expression of MUC5AC and MUC5B mucins in normal and cystic fibrosis lung

Hypersecretion of airway mucus is a characteristic feature of chronic airway diseases like cystic fibrosis (CF) and leads via impairment of the muco-ciliary clearance and bacterial superinfection to respiratory failure. The major components of the mucus matrix forming family of mucins in the airways are MUC5AC and MUC5B. To investigate the expression of these glycoproteins in CF, immunohistochemistry was carried out on trachea, bronchi and peripheral lung obtained from CF patients and compared to normal lung tissues. MUC5AC immunohistochemistry demonstrated signals in goblet cells of the epithelial lining. Also, goblet cells inside glandular secretory ducts revealed MUC5AC-positive staining. In comparison to those from normal subjects, CF sections were characterized by inflammatory changes and goblet cell hyperplasia, resulting in increased numbers of MUC5AC-positive cells. Immunohistochemical staining for MUC5B showed abundant staining of submucosal glands and epithelial goblet cells. Inside the glands, the immunoreactivity was restricted to glandular mucous cells. MUC5AC and MUC5B are expressed in the same histological pattern in CF compared to normal tissues with an increase of MUC5AC-positive cells due to goblet cell hyper- and metaplasia.

Distribution and function of the peptide transporter PEPT2 in normal and cystic fibrosis human lung

BACKGROUND

Aerosol administration of peptide based drugs has an important role in the treatment of various pulmonary and systemic diseases. The characterisation of pulmonary peptide transport pathways can lead to new strategies in aerosol drug treatment.

METHODS

Immunohistochemistry and ex vivo uptake studies were established to assess the distribution and activity of the beta-lactam transporting high affinity proton coupled peptide transporter PEPT2 in normal and cystic fibrosis human airway tissue.

RESULTS

PEPT2 immunoreactivity in normal human airways was localised to cells of the tracheal and bronchial epithelium and the endothelium of small vessels. In peripheral lung immunoreactivity was restricted to type II pneumocytes. In sections of cystic fibrosis lung a similar pattern of distribution was obtained with signals localised to endothelial cells, airway epithelium, and type II pneumocytes. Functional ex vivo uptake studies with fresh lung specimens led to an uptake of the fluorophore conjugated dipeptide derivative D-Ala-L-Lys-AMCA into bronchial epithelial cells and type II pneumocytes. This uptake was competitively inhibited by dipeptides and cephalosporins but not ACE inhibitors, indicating a substrate specificity as described for PEPT2.

CONCLUSIONS

These findings provide evidence for the expression and function of the peptide transporter PEPT2 in the normal and cystic fibrosis human respiratory tract and suggest that PEPT2 is likely to play a role in the transport of pulmonary peptides and peptidomimetics.

Relationship between exhaled nitric oxide and mucosal eosinophilic inflammation in children with difficult asthma, after treatment with oral prednisolone

Exhaled nitric oxide (FE(NO)) has been proposed as a noninvasive marker of airway inflammation in asthma, and may reflect airway eosinophilia. We examined the relationship between FE(NO) and eosinophilic inflammation in endobronchial biopsies from 31 children with difficult asthma (mean age [range] 11.9 [6-17] yr), following 2 wk of prednisolone (40 mg/d). Endobronchial biopsy was also performed in seven children without asthma. Biopsy eosinophils were detected using antibody to major basic protein, and point-counting used to derive an "eosinophil score." FE(NO) readings and suitable biopsies for analysis were both obtained in 21 of 31 children with asthma. Adherence to prednisolone was demonstrated in 17 of these 21. Within this group, there was a correlation between FE(NO) and eosinophil score (r = 0.54, p = 0.03). The relationship was strongest in patients with persistent symptoms after prednisolone, in whom FE(NO) > 7 ppb was associated with a raised eosinophil score. For all patients, FE(NO) < 7 ppb was associated with an eosinophil score within the nonasthmatic range, regardless of symptoms. We propose that FE(NO) is associated with eosinophilic inflammation in children with difficult asthma, following prednisolone, and may help in identifying patients in whom persistent symptoms are associated with airway eosinophilia.

Expression of GATA family of transcription factors in T-cells, monocytes and bronchial biopsies

GATA-binding proteins are a subfamily of zinc finger transcription factors with six members (GATA-1-6) that interact with the GATA deoxyribonucleic acid (DNA) sequence. This sequence is found in the regulatory regions of many genes including those encoding T-helper 2 (Th2)-like cytokines, receptors, adhesion molecules and enzymes, which may be important in the pathogenesis of bronchial asthma. The expression of GATA-3, 4 and -6 was investigated in peripheral blood T-lymphocytes and monocytes and bronchial biopsies from 11 normal subjects and 10 steroid-naive asthmatic patients. Using Western blot analysis, T-cells from asthmatic subjects expressed 5 times the level of GATA-3 compared to that in normals. Confocal microscopy indicated that GATA-3 expression was both nuclear and cytoplasmic. GATA DNA binding complex containing GATA-3 was elevated in Th2 cells as determined by electrophorectic mobility shift assay. In contrast, monocytes from normal and asthmatic subjects expressed GATA-4 and -6 in equal amounts, but no GATA-3 was found. Using immunohistochemistry in bronchial biopsies, epithelial cells expressed high levels of GATA-3, GATA-4 and GATA-6 proteins. Comparison of Western blots of bronchial biopsies showed no significant differences between normal and asthmatic subjects. In conclusion, the increased expression of GATA-3 in asthmatic T-cells may underlie augmented T-helper 2-like cytokines in this disease. However, the unaltered GATA-3 expression in epithelial cells suggests a distinct role for GATA-3 in these cells unrelated to T-helper 2-like cytokine release. Finally, no evidence was found for an increased expression of GATA-4 and GATA-6 in asthma.

Soluble antagonists to interleukin-1 (IL-1) and tumor necrosis factor (TNF) inhibits loss of tissue attachment in experimental periodontitis

BACKGROUND, AIMS

Periodontal disease is a significant cause of tooth loss among adults and is characterized by the alteration and permanent destruction of the deeper periodontal tissues. Although the presence of pathologic microbes is required to trigger this process, the amplification and progression of the diseased state is believed to rely heavily on the production of host mediators in response to bacteria or their metabolic products. The inflammatory response is effective in preventing large-scale colonization of the gingival tissues by bacteria that lie in close proximity to the tooth surface or within the gingival sulcus. It has been postulated that the host-response in some individuals may lead to an over-reaction to invading oral pathogens resulting in the destruction of periodontal tissues.

METHODS

Several host-derived mediators are believed to contribute to this response. Two agents considered to be essential in periodontal destruction are interleukin-1 (IL-1) and tumor necrosis factor (TNF). We investigated the role of IL-1 and TNF in the loss of connective tissue attachment in a Macaca fascicularis primate model of experimental periodontitis. Silk ligatures impregnated with the periodontal pathogen, Porphyromonas gingivalis were wrapped around the posterior teeth and the activity of IL-1 and TNF were inhibited by soluble receptors to these proinflammatory cytokines via local injection into interdental papillae.

RESULTS

Histomorphometric analysis indicates that IL-1 and TNF antagonists significantly reduced the loss of connective tissue attachment by approximately 51% and the loss of alveolar bone height by almost 91%, both of which were statistically significant.

CONCLUSION

This investigation demonstrates that the loss of connective tissue attachment and progression of periodontal disease can be retarded by antagonists to specific host mediators such as IL-1 and TNF and may provide a potential treatment modality to combat the disease process.

Expression of heme oxygenase isoenzymes 1 and 2 in normal and asthmatic airways: effect of inhaled corticosteroids

Heme oxygenase (HO) is considered to be an antioxidant enzyme that catabolizes heme to produce carbon monoxide (CO) and biliverdin. We determined the expression and distribution of HO-1 and HO-2, two isoenzymes of HO, in the airways of patients with asthma, and determined the effect of inhaled corticosteroid therapy. Immunostaining for both enzymes was widely distributed in the airways' submucosa, particularly in airway epithelium and submucosal macrophages (CD68(+)) as determined by double immunostaining. There was no difference in intensity and extent of staining in biopsies from normal subjects (n = 10) and subjects with asthma (n = 10). Following 1 mo of treatment with inhaled corticosteroids (budesonide 1,600 microg/d), there was no significant change in the expression and distribution of either HO-1 or HO-2 in the airways' submucosa in eight subjects with mild asthma, despite a significant reduction in airway eosinophils and a reduction in bronchial responsiveness to methacholine. Levels of exhaled nitric oxide were significantly reduced, but exhaled CO levels remained unchanged by the treatment. Treatment with a placebo inhaler (n = 8) had no effects on these parameters. Thus, both HO-1 and HO-2 are extensively distributed equally in normal subjects and subjects with asthma, and are not modulated by inhaled corticosteroid therapy in subjects with asthma. HO may be an important endogenous antioxidant enzyme.

Relationship between exhaled nitric oxide and mucosal eosinophilic inflammation in mild to moderately severe asthma

BACKGROUND

Exhaled levels of nitric oxide (NO) are raised in asthma but the relationship between exhaled NO levels and a direct measure of airway inflammation has not been investigated in asthmatic patients treated with inhaled steroids.

METHODS

The relationship between exhaled NO levels, clinical measures of asthma control, and direct markers of airway inflammation were studied in patients with asthma treated with and without inhaled corticosteroids. Thirty two asthmatic patients (16 not using inhaled steroids and 16 using inhaled beclomethasone dipropionate, 400-1000 microg/day) were monitored with respect to measures of asthma control including lung function, symptom scores, medication usage, and variability of peak expiratory flow (PEF) for one month. Measurements of exhaled NO and fibreoptic bronchoscopy were performed at the end of the monitoring period. Bronchial mucosal biopsy specimens were stained with an anti-MBP antibody for quantification of eosinophils.

RESULTS

There was no significant difference in lung function, symptom scores, or medication usage between the two groups, but there was a significant difference in PEF variability (8.7 (1.2)% in steroid naive patients versus 13.6 (1.9)% in steroid treated patients, p<0.05) and exhaled NO levels (9.9 (3.5) ppb in steroid naive patients versus 13.6 (2.0) ppb in steroid treated patients, p<0.05). There was no correlation between exhaled NO and mucosal eosinophils, or between NO and conventional measures of asthma control. There was a significant correlation between mucosal eosinophils and lung function (r = -0.43, p<0.05).

CONCLUSIONS

Exhaled NO levels do not reflect airway mucosal eosinophilia and these markers reflect different aspects of airway inflammation. The clinical usefulness of exhaled NO needs to be determined in prospective longitudinal studies.

Interleukin-1 and tumor necrosis factor antagonists inhibit the progression of inflammatory cell infiltration toward alveolar bone in experimental periodontitis

Periodontal disease is a significant cause of tooth loss in humans and is one of the most prevalent diseases associated with bone loss. Following bacterial colonization, the gingiva becomes inflamed and, in some cases, progresses to destruction of alveolar bone. To investigate the temporal movement of inflammatory cells toward alveolar bone and the role of interleukin-1 (IL-1) and tumor necrosis factor (TNF) in this process, studies were carried out in a Macaca fascicularis primate model of experimental periodontitis. IL-1 and TNF activity was inhibited by local application of soluble receptors to IL-1 and TNF by injection into interdental papillae. The results indicate that following induction of experimental periodontitis, the front of inflammatory cells progresses toward alveolar bone and is associated with osteoclast formation. These processes are inhibited by blockers to IL-1 and TNF. These studies suggest that the conversion from gingivitis to periodontitis is directly associated with the movement of an inflammatory infiltrate toward alveolar bone, and that this activity is at least partially dependent upon IL-1 and/ or TNF.

Single-molecule high-resolution structure and electron conduction of photosystem II from scanning tunneling microscopy and spectroscopy

Scanning tunneling microscopy (STM) and spectroscopy (STS) were used to obtain the first direct high resolution ( approximately 0.3 nm) images of single isolated Photosystem II (PS II) molecules, and to determine the supramolecular organization of oxygen-evolving PS II core complexes and PS II membrane fragments including the identification, assignment, location and dimensions of the polypeptide units. Our results predict a unique structural model which we then compare with alternative models. We show that the combination of quasi-constant-height mode STM operation, STS and suitable choice of sample-substrate preparations can be used to enable investigation of the structure and function of single PS II particles under normal thermodynamic and hydration conditions without the requirement and complications of ordered PS II arrays or crystals. STS was also used to characterize single-molecule electron conduction and tunneling mechanisms in PS II including the semiconduction and photoconduction behavior of the reaction center and photoexcitation effects in the light-harvesting complex LHC II.

IL-1 and TNF antagonists inhibit the inflammatory response and bone loss in experimental periodontitis

Periodontal disease is the most frequent cause of tooth loss in humans and is the most prevalent disease associated with bone loss, including osteoporosis. Periodontal destruction is initiated by bacteria that colonize the tooth surface, leading to inflammation and bone resorption. To assess the roles of IL-1 and TNF in this process, studies were conducted in a Macaca fascicularis primate model of experimental periodontitis. Function-blocking soluble receptors to IL-1 and TNF were applied by local injection to sites with induced periodontal destruction and compared with similar sites injected with vehicle alone. The results indicate that injection of soluble receptors to IL-1 and TNF inhibited by approximately 80% the recruitment of inflammatory cells in close proximity to bone. The formation of osteoclasts was reduced by 67% at the experimental sites compared with that at the control sites, and the amount of bone loss was reduced by 60%. All results were statistically significant (p < 0.01). These findings indicate that a significant component of the pathologic process of periodontitis is due to IL-1/TNF activity, since inhibiting IL-1/TNF reduces both inflammatory cell recruitment and bone loss. The data also suggest that inflammation associated with gingivitis is actively protective, since blocking further up-regulation of the host response with IL-1/TNF inhibitors does not cause periodontal damage. Furthermore, these results coupled with recent evidence that IL-1 and TNF participate in endocrine-associated osteoporosis suggest that multiple pathologies involving excessive loss of bone may operate through a common mechanism involving IL-1 and/or TNF.

IL-1 and TNF Antagonists Inhibit the Inflammatory Response and Bone Loss in Experimental Periodontitis

Periodontal disease is the most frequent cause of tooth loss in humans and is the most prevalent disease associated with bone loss, including osteoporosis. Periodontal destruction is initiated by bacteria that colonize the tooth surface, leading to inflammation and bone resorption. To assess the roles of IL-1 and TNF in this process, studies were conducted in a Macaca fascicularis primate model of experimental periodontitis. Function-blocking soluble receptors to IL-1 and TNF were applied by local injection to sites with induced periodontal destruction and compared with similar sites injected with vehicle alone. The results indicate that injection of soluble receptors to IL-1 and TNF inhibited by approximately 80% the recruitment of inflammatory cells in close proximity to bone. The formation of osteoclasts was reduced by 67% at the experimental sites compared with that at the control sites, and the amount of bone loss was reduced by 60%. All results were statistically significant (p &lt; 0.01). These findings indicate that a significant component of the pathologic process of periodontitis is due to IL-1/TNF activity, since inhibiting IL-1/TNF reduces both inflammatory cell recruitment and bone loss. The data also suggest that inflammation associated with gingivitis is actively protective, since blocking further up-regulation of the host response with IL-1/TNF inhibitors does not cause periodontal damage. Furthermore, these results coupled with recent evidence that IL-1 and TNF participate in endocrine-associated osteoporosis suggest that multiple pathologies involving excessive loss of bone may operate through a common mechanism involving IL-1 and/or TNF.

Characterization of monoclonal antibodies raised to C-terminal peptides of pS2: a major trefoil peptide and motility factor expressed in adenocarcinomas and regions of mucosal injury

Two novel monoclonal antibodies, GE1 and GE2 raised against the C-terminal 31 and 28 amino acids of the estrogen-inducible trefoil peptide pS2, are described. Both antibodies are able to detect pS2 in formalin-fixed, paraffin-embedded tissues. Conditions are presented under which pS2 can be shown in cell lines by immunohistochemistry that has previously been problematic. The antibodies can specifically show the presence of pS2 in cell lysates by Western blotting and immunoprecipitation. In the form of an affinity column, the GE1 monoclonal antibody can be used to purify pS2 from MCF-7 supernatants. The eluted peptide from the GE1 affinity column shows a single band at 6,600 Da (predicted size for pS2) on Western blotting. These antibodies are valuable reagents in the analysis of the role of trefoil peptides in the maintenance of mucosal integrity, and may have applications in the assessment of pS2 expression in chronic gastrointestinal ulceration and adenocarcinomas that secrete pS2, where it may serve as a prognostic marker.

Establishment and characterisation of two cell lines derived from a primary adenocarcinoma of the duodenum

Aims-To establish two cell lines from a primary duodenal adenocarcinoma; to describe the morphological, growth, ploidy, and immunophenotypic characteristics of these cell lines.Methods-The cell lines, designated DAC/S and DAC/E, were characterised using both in vitro and in vivo cell culture techniques, light and electron microscopy, immunocytochemistry, and FACS analyses.Results-Both cell lines have an epithelial origin, are aneuploid and display characteristics of transformed cells. The cell lines differ from each other in morphology, doubling time and serum requirements. These cell lines are anchorage dependent and do not grow in nude mice.Conclusions-DAC/S and DAC/E cell lines are derived from neoplastic epithelium and could provide in vitro model systems for future investigations of the cell and molecular biology of duodenal neoplasia.

Daily hassles, major and minor life events, and their interaction with sociotropy and autonomy

A cross-sectional study investigated whether Beck's (1983; 1987) (Treatment of depression: Old controversies and new approaches. New York: Raven Press; Journal of Cognitive Psychotherapy, 1, 2-27) cognitive-personality traits of sociotropy and autonomy had a specific interaction with daily minor life events (hassles) or major life experiences within the interpersonal and autonomous domains. Ninety-four undergraduates were administered the revised Sociotropy-Autonomy Scale (SAS), Beck Depression Inventory (BDI), Negative Experiences Inventory--Student Version (NEI), List of Threatening Events and the Hassles and Uplifts Scale. Hierarchical multiple regression analysis, with the BDI as the dependent variable, revealed a specific congruent interaction between Solitude, one of the two dimensions of autonomy, and NEI negative autonomous events. Sociotropy and the other dimension of autonomy, Independence, did not interact significantly with any of the life event scales. The findings suggest that more severe life events rather than daily hassles or strains may be more relevant when investigating cognitive diathesis-stress interactions in dysphoria.

TGF-alpha can act as morphogen and/or mitogen in a colon-cancer cell line

Transforming growth factor alpha (TGF-alpha) has multifunctional biological effects on a variety of mesenchymal and epithelial cells. It is a potent mitogen for a number of normal and transformed cell types, regulates extracellular matrix (ECM) production and promotes breast, kidney and lung morphogenesis. To clarify the role of ECM proteins in the morphogenetic and mitogenic effects of TGF-alpha, we have used a human colon carcinoma cell line (SW1222) which expresses EGF receptor. Here we show that TGF-alpha at 1 ng/ml increases the proliferation of SW1222 cells, but only when they are cultured on plastic rather than collagen-coated plates. Higher concentrations of TGF-alpha (10 ng/ml) did not increase cell proliferation but significantly enhanced the crypt-like glandular differentiation when cells were grown in 3-dimensional collagen gel (p = 0.027). These effects were accompanied by increased expression of alpha 2 beta 1 and alpha 3 beta 1 integrin molecules, which are receptors for extracellular matrix proteins, and by a statistically significant increase in binding of SW1222 cells to type-1 collagen. The effects of TGF-alpha both on binding to type-1 collagen and on morphological differentiation in 3-dimensional collagen gel were inhibited by monoclonal antibodies recognizing the alpha 2 beta 1 integrin. These data indicate that the morphogenetic or mitogenic activities of TGF-alpha are critically dependent on cellular interactions with extracellular matrix proteins and are primarily mediated by the alpha 2 beta 1 integrin receptor. Inappropriate expression of this growth factor, seen in tumours whose cell-matrix interactions are greatly impaired, could have deleterious effects on the maintenance of normal tissue architecture and growth control.

Electroencephalogram epileptiform abnormalities in candidates for aircrew training

For 30 years the Royal Air Force has used the EEG as part of the medical screening of candidates for aircrew training. A total of 13,658 males aged 17-25 years have been examined. None had a previous history of significant illness. Sixty-nine (0.5%) of these showed unequivocal epileptiform discharges, 44 (58%) occurring only on photic stimulation. Those with EEG discharges of uncertain significance such as 6 and 14 Hz positive spikes, 6 Hz spike and wave, and non-specific paroxysmal activity were not included. A group of 43 with a follow-up period of 5-29 years have been reviewed. Only one person developed unequivocal epilepsy. If this rate is combined with results from similar studies, the chance of healthy individuals with EEG abnormalities of this type subsequently developing epilepsy is 2-3%.