Notizen: The distribution of primary health care professionals in England and Wales is inequitable, with relatively lower concentrations of professionals in deprived areas. The objective of the present study was to determine whether graduate health professionals would be willing to work in under-served areas in return for educational loan repayment. The study group consisted of a convenience sample of 50 newly qualified and trainee general practitioners, and 50 newly qualified community nurses and health visitors in mid- and west Wales. At interview, the subjects were presented with descriptions of general practices and asked to indicate their preferred practice. Practice descriptions varied systematically in terms of location (i.e. urban, suburban and rural), population deprivation (i.e. deprived or mixed affluent/deprived) and availability of loan repayment (i.e. none or loans paid off over a period of between one and 4 years). The main outcome was the probability that a practice with loan repayment was chosen. Compared with a suburban practice, a one-year loan repayment option made the rural and urban deprived practices 1.6 times and 1.2 times more likely to be chosen, respectively. Nurses were generally more willing than doctors to work in a deprived area in return for loan repayment. The findings suggest that loan repayment may offset health professionals’ aversion to working in deprived areas. Such a scheme needs to be piloted to see whether it does offer value for money in recruiting health professionals to under-served areas.

Notizen: Background  Hev b 5 is a major latex allergen recognized predominantly by latex-allergic health care workers (HCWs). Recombinant Hev b 5 (rHev b 5) was previously expressed as a fusion protein with maltose binding protein (MBP), itself an immunogenic molecule; therefore non-fusion rHev b 5 is desirable. Moreover, standardized immunological assays for the detection of Hev b 5 are currently lacking and may have important implications for both allergen avoidance and diagnosis in latex allergy.Objectives  To generate and use Hev b 5-specific mAbs to determine the relative abundance of Hev b 5 in different latex extracts, correlating this with the IgE reactivity of latex-allergic HCWs and to produce non-fusion rHev b 5.Methods  For the production of mAbs, mice were immunized with rHev b 5/MBP fusion protein and mAbs selected with rHev b 5/MBP but not MBP reactivity. The mAb reactivity was compared with polyclonal IgE from latex-allergic HCWs using direct and inhibition ELISA and immunoblot assays. Recombinant Hev b 5 was expressed and purified in the pPROEX-HTa bacterial expression system.Results  Four Hev b 5-specific mAbs were produced. Immunoblotting and ELISA using the mAbs indicate abundant Hev b 5 in high protein powdered latex glove extracts as compared with crude latex sap extracts. High quality surgical gloves with no detectable protein have no detectable Hev b 5. Inhibition ELISAs using serum IgE from latex-allergic HCWs and Hev b 5-specific mAbs gave strong correlation. Non-fusion recombinant Hev b 5 was successfully expressed and purified, showing reactivity with both the Hev b 5-specific mAbs and serum IgE of latex-allergic HCWs.Conclusion  Hev b 5-specific mAbs and human IgE from latex-allergic HCWs demonstrate the greater content of Hev b 5 in high protein powdered glove extracts. This may explain the observed higher frequency of sensitization to this allergen in HCWs.

Notizen: Background Monoclonal antibodies are a valuable tool in the study of allergens, but the technology used in their generation can be slow and labour-intensive. Therefore, we have examined recombinant antibody development by phage-display against single allergens and protein mixtures.Objective We used the avian immunoglobulin system (generated from single VH and VL genes) to provide a rapid method for generating highly specific recombinant antibody fragments from a minimal number of animals.Methods A single-chain antibody fragment (scFv) library was generated from a single chicken immunized with model allergens. ScFvs were isolated by phage-display and their properties investigated by ELISA and Western blot.Results Mono-specific scFvs were generated against recombinant Fel d 1 and native Amb a 1. Pannings against yellow jacket venom extracts only yielded clones that reacted with multiple proteins in the venom extract. The scFvs from each panning type were effectively expressed in Escherichia coli and readily purified. Highly specific and sensitive recognition of Fel d 1 and Amb a 1 was demonstrated in ELISA, with scFvs displaying antibody-concentration-dependent absorbance curves down to picogram levels of antibody. The specificity of selected antibodies for their cognate antigen was further confirmed in Western blot analysis, with scFvs directed to either Fel d 1 or Amb a 1 showing no reactivity for the other antigens used in immunization. Anti-Amb a 1 scFvs also mapped Amb a 1-isoform location in Western blot of ragweed extracts separated by 2D SDS-PAGE. DNA sequence analysis of scFvs showed that multiple different clones had been generated against Fel d 1 and Amb a 1. Using two anti-Fel d 1 scFv for ELISA analysis of Fel d 1 content in crude cat pelt extracts, we could produce data which were highly similar (P=0.33 and 0.89 by paired t-test analysis) to those obtained using conventional assays (radial immunodiffusion).Conclusion Phage-display technology may generate multiple allergen-specific recombinant antibody fragments from a single chicken, to allergens from mammalian, plant and insect sources. The resulting antibody fragments are of demonstrable use in allergen identification and quantification, in comparison with standard immunoassays.

Notizen: Background In this study we examine the variability among unstandardized cockroach allergen extracts.Methods We obtained 24 aqueous and glycerinated cockroach allergen extracts from nine manufacturers. We used previously characterized cockroach extracts, E2-Cg and E2-Ca, as references. The modified ninhydrin assay was used to determine protein concentration of each extract. Relative potencies of extracts were determined by competition ELISA, using a human allergic serum pool. Bla g 1 and Bla g 2 levels of glycerinated German cockroach extracts were determined by ELISA using monoclonal antibodies. Extracts were also analysed by SDS-PAGE.Results Commercial cockroach allergen extracts had highly variable protein contents that were lower than the protein contents of the references. Electrophoretic data confirmed the presence of a variable number and intensity of protein bands in extracts among manufacturers. The relative potencies of the commercial extracts were between 10 and 782 BAU/mL for German cockroach and 10–250 BAU/mL for American cockroach. The mean Bla g 1 content of the commercial extracts was significantly lower than that of the reference (P = 0.001). The mean Bla g 2 content of the commercial extracts was higher than that of the E2-Cg reference but the Bla g 2 levels were more variable compared to Bla g 1. In glycerinated German cockroach extracts, protein concentrations, relative potencies and specific allergen levels were significantly correlated (P 〈 0.001).Conclusion Our tests indicate that commercially available cockroach allergen extracts are variable in protein content, electrophoretic banding patterns, relative potency and Bla g 2 levels. In glycerinated German cockroach extracts, protein concentrations, relative potencies and specific allergen levels were significantly correlated.

Notizen: summary  One of the most common symptoms of temporomandibular disorders is an internal derangement (ID). The aim of this study was to test the inter-observer reliability of the recognition of IDs by means of auscultation, palpation or both. To that end, 120 women and 100 men were screened by two trained examiners for the presence of IDs. Anterior disc displacement was diagnosed in 14% of the cases and hypermobility in 12%. In 4% of the cases, the ID was classified as ‘other’. The inter-rater reliability (Cohen's kappa) was moderate for the presence of an ID for all techniques, while for the classification into type, an almost perfect reliability was found for the combined technique. It was concluded that the type of ID can best be established with the combination of auscultation and palpation; for the establishment of an ID as such, any of the three techniques would suffice.

Notizen: The influence of head posture on movement paths of the incisal point (IP) and of the mandibular condyles during free open–close movements was studied. Ten persons, without craniomandibular or cervical spine disorders, participated in the study. Open close mandibular movements were recorded with the head in five postures, viz., natural head posture, forward head posture, military posture, and lateroflexion to the right and to the left side, using the Oral Kinesiologic Analysis System (OKAS-3D). This study showed that in a military head posture, the opening movement path of the incisal point is shifted anteriorly relative to the path in a natural head posture. In a forward head posture, the movement path is shifted posteriorly whereas during lateroflexion, it deviates to the side the head has moved to. Moreover, the intra-articular distance in the temporomandibular joint during closing is smaller with the head in military posture and greater in forward head posture, as compared to the natural head posture. During lateroflexion, the intra-articular distance on the ipsilateral side is smaller. The influence of head posture upon the kinematics of the mandible is probably a manifestation of differences in mandibular loading in the different head postures.

Notizen: Anterior disc displacements are an important diagnostic subgroup (Group II) of TM disorders according to the Research Diagnostic Criteria (RDC; Dworkin & LeResche, 1992). Although the RDC yields clear-cut criteria for the diagnosis of a disc displacement, the interobserver reliability for the clinical recognition of joint sounds is highly variable. This high variance may be caused by the fact that the clinical assessment of joint sounds is difficult. In many previous studies, auscultation with a stethoscope was used. This technique is often claimed to be the most reliable one. However, it is unclear whether in these studies, auscultation was performed without simultaneous palpation of the contralateral joint. Therefore, the aim of the present study was to test the interobserver reliability of the clinical assessment of TMJ sounds by means of auscultation, palpation or both. A total of 220 undergraduate students (100 men; 120 women; mean age 21·9 ± 3·6 years) was examined independently by two calibrated dentists for the presence, probable presence or absence of sounds caused by anterior disc displacement, hypermobility, or another cause. The 79 students underwent auscultation only (i.e. without contralateral manual palpation); 87 students underwent bilateral palpation; the remainder (54 students) was subjected to both auscultation and palpation. The results show that the combination technique yields the highest reliability (Cohen's κ=0·53). For other techniques, κ-values of 0·46 (auscultation) and 0·48 (palpation) were found. It was concluded that the combination of auscultation and palpation yields the highest interobserver reliability for the recognition of TMJ sounds, although the differences with other techniques were small. (Supported by the IOT)

Notizen: In previous studies to the relative contribution of the jaw closing muscles to the maintenance of submaximal clenching levels, a considerable variation in the electromyography (EMG) activities of these muscles during subsequent efforts was found. In this study, it was examined to what extent this variation could be explained by coincidental variations in mandibular positioning. From seven healthy individuals, a total of 90 EMG sweeps was recorded: three conditions (intercuspal position and two types of stabilization appliances) × three clenching levels (10, 30 and 50% of maximum voluntary contraction level) × 10 repetitions. Mandibular position was monitored with a six degrees of freedom opto-electronic jaw movement recording system. Variations in mandibular positioning during subsequent, submaximal clenching efforts explained up to 25% of the variance in the indices that quantify the relative contribution of the jaw closing muscles to the total clenching effort (P=0·000; ANOVA). Only a weak dependency of positioning upon clenching condition was found whereas during higher clenching levels, the positioning effect tended to be smaller than during lower levels. In conclusion small, coincidental variations in mandibular positioning during subsequent clenching efforts partly explain the variance in EMG activity of jaw closing muscles, especially at lower clenching levels.