Polarimetric studies on camphor (2) as well as IR studies on crotonaldehyde (CA; 1) and benzonitrile (BN; 3) confirm the conclusion of a previously published NMR study on crotonaldehyde that lithium perchlorate (LP) weakly binds to probe bases in diethyl ether (DE). The weak binding is a consequence of the fact that the lithium ion (actually the LP ion pair and higher aggregates), a powerful Lewis acid in the gas phase, competitively binds to ether and the added base. Methylene camphor (5), (E)-1,3-pentadiene (4), camphene, and phenylacetylene (6) do not bind to LP in DE. Shifts to lower energy of the CO modes of CA in ether solutions containing increasing amounts of LP are consistent with moderate increases in solvent polarity. Only small or no shifts are seen in the C⋮N modes of BN and its 1:1 complex with added LP. Because the C⋮N and especially CO modes are blue shifted under external applied pressure, the large internal pressures of LP/DE do not mimic external applied pressure. Likewise, the small or no changes observed in λmax for the absorption and emission spectra of anthracene (9) and azulene (8) in ether as a function of LP concentration do not conform to what is observed under external applied pressure. Studies of the Diels−Alder reaction of (E)-1,3-pentadiene with methyl acrylate show that the reaction is entirely catalyzed in LP/DE; polarity and internal pressure do not influence product selectivity in this reaction.

Periodontitis, a bacterial-induced infection of the supporting soft and hard tissues of the teeth (the periodontium), is common in patients with rheumatoid arthritis (RA). As RA and periodontitis underlie common inflammatory pathways, targeting the progression of RA might mediate both periodontitis and RA. On the other hand, patients with RA on immunosuppressive medication have an increased risk of infection. Therefore, the objective of this longitudinal observation study was to assess the effect of methotrexate (MTX) and anti-tumor necrosis factor-α (anti-TNF, etanercept) treatment on the periodontal condition of RA patients. Overall, 14 dentate treatment-naive RA patients starting with MTX and 12 dentate RA patients starting with anti-TNF therapy in addition to MTX were included. Follow-up was scheduled matching the routine protocol for the respective treatments. Prior to the anti-rheumatic treatment with MTX or the anti-TNF therapy in addition to MTX, and during follow-up, i.e., 2 months for MTX, and 3 and 6 months for the anti-TNF therapy in addition to MTX, the periodontal inflamed surface area (PISA) was measured. The efficacy of the anti-rheumatic treatment was assessed by determining the change in RA disease activity (DAS28-ESR). Furthermore, the erythrocyte sedimentation rates were determined and the levels of C-reactive protein, IgM-rheumatoid factor, anti-cyclic citrullinated protein antibodies, and antibodies to the periodontal pathogen Porphyromonas gingivalis, were measured. Subgingival sampling and microbiological characterization of the subgingival microflora was done at baseline. MTX or anti-TNF treatment did not result in an improvement of the periodontal condition, while both treatments significantly improved DAS28 scores (both p < 0.01), and reduced C-reactive protein levels and erythrocyte sedimentation rates (both p < 0.05). It is concluded that anti-rheumatic treatment (MTX and anti-TNF) has negligible influence on the periodontal condition of RA patients.

A case-control study was conducted in which the amount and sites (fresh-water lakes and rivers, chlorinated pools, or the ocean) of recent swimming by 105 patients with otitis externa were compared with that of 239 controls. Swimming during the week prior to the visit was strongly associated with otitis externa. When the 80 cases and 127 controls with a history of recent swimming were compared, otitis externa was positively associated with the amount of swimming during the preceding week. Otitis externa was also positively associated with swimming in fresh water compared with ocean or pool swimming with the magnitude of this association being more pronounced at higher levels of exposure.

The effect of smoking on respiratory illness was investigated at a naval recruit camp. All recruits entering training during an 11-month period, beginning in February 1971, were included in the study. Questionnaires in regard to smoking habits were administered on arrival and during the last week of training. Facts of illness were obtained from each recruit's health record during the last week of training and abstracted onto electronic accounting machine (EAM) cards. Data on a sample of 1,100 men, who had complete records, were analyzed. Two thirds of the men were smokers on arrival. Heavy smokers had a longer history of smoking. The majority of recruits decreased smoking during training. Significantly more heavy smokers than light smokers or nonsmokers had symptoms of chronic respiratory involvement. No statistically significant increases in respiratory illness were observed in smokers.

BackgroundOverlapping molecular pathways of inflammation have been implicated in periodontitis and rheumatoid arthritis (RA). The presence of shared underlying inflammatory pathogenesis mediating the progression of periodontitis and RA could provide potentially important common therapeutic targets.ObjectivesThe primary purpose of this observational study was to determine the effect of methotrexate (MTX) and anti-TNFα (etanercept) on clinical parameters of periodontitis. Influence of periodontitis on efficacy of medical treatment of RA was a secondary endpoint.MethodsFourteen treatment-naïve patients starting with MTX and 12 patients starting with anti-TNFα therapy, fulfilling the ACR/EULAR classification criteria for RA (2010), older than 18 years, and with natural dentition were included. One patient was excluded because of antibiotic use for oral infection <3 months prior to the study. Four patients stopped treatment with etanercept after the first follow up visit because of patient related factors. Before starting medical treatment for RA and after 2 months (MTX) or 3 months (anti-TNFα), periodontal inflammatory burden was quantified with the periodontal inflamed surface area (PISA) (Nesse et al. 2008). Subgingival presence of P. gingivalis was determined by anaerobic culture. In addition, radiographic intra-oral pathologies (furcation involvement, peri-apical pathology and cariës) were assessed on panoramic radiographs. Oral hygiene was measured using full mouth plaque scores. Efficacy of anti-rheumatic treatment was measured by change in RA disease activity (DAS28-ESR).ResultsTreatment with MTX of anti-TNFα significantly improved DAS scores (both p<0.001) and erythrocyte sedimentation rates (ESR) (both p<0.05). PISA did not change significantly after starting with treatment with MTX or anti-TNFα. Also, PISA or presence of other intra-oral pathologies were not associated with changes in DAS scores and ESRConclusionsAnti-rheumatic treatment did not have significant impact on clinical periodontal parameters. Within the limitations of this study (PISA scores were rather low) PISA and presence of other intra-oral pathologies were not of associated with efficacy of anti-rheumatic treatment.ReferencesNesse, W., Abbas, F., van der Ploeg, I., Spijkervet, F.K., Dijkstra, P.U. & Vissink, A. (2008) Periodontal inflamed surface area: quantifying inflammatory burden. J.Clin.Periodontol. 35, 668–673.Disclosure of InterestM. de Smit: None declared, M. Posthumus: None declared, A.-M. van Brenk: None declared, L. Oosting: None declared, G. Springer: None declared, E. Brouwer: None declared, M. Bijl Grant/research support from: Pfizer, J. Westra: None declared