Biomedical subjects

D Buck

Publications and source records attributed to D Buck.

At least 19 recordsLinked to original sources

PubMed2006

Distance stereoacuity in intermittent exotropia.

BACKGROUND: Studies of distance stereoacuity in intermittent exotropia suggest that normal stereoacuity corresponds to good control of the deviation and that reduced or negative stereoacuity signifies poorer control. AIM: : To evaluate distance stereoacuity in intermittent exotropia using the Frisby Davis Distance stereo test (FD2). METHODS: Children with intermittent exotropia where the near angle was less than or equal to distance were eligible for recruitment. Standardised prospective data collection included FD2 distance stereoacuity. This was a longitudinal study in which outcomes are reported for baseline, last follow-up (> or =6 months before any surgery) or preoperative and last postoperative visits for those undergoing surgery. RESULTS: 110 children with intermittent exotropia had FD2 stereoacuity tested at baseline: 70 comprehended the test. Mean (standard deviation (SD)) age was 4.6 (1.7) years (range 2-10 years). 41/70 (59%) showed positive responses: mean (SD) stereoacuity 30 (12) s of arc. The mean follow-up period before any surgery was 13 months (range 6-27 months). At follow-up, mean (SD) stereoacuity was 24 (11) s of arc. Preoperative and postoperative stereoacuity were not significantly different from those not undergoing surgery. CONCLUSION: This study was the first to report distance stereoacuity in intermittent exotropia using the FD2 stereo test: patients with intermittent exotropia can achieve normal levels of distance stereoacuity, but a considerable proportion, despite comprehending, showed a negative response. This suggests that using the FD2, distance stereoacuity in intermittent exotropia is either absent or normal rather than reduced. Possible reasons for this and its implications are discussed.

Child↗

PubMed2006

Analysis of the C/T(-1) single nucleotide polymorphism in the CD40 gene in multiple sclerosis.

The costimulatory CD40-CD40L pathway plays a critical role in the generation and maintenance of adaptive immune responses. Genetic interference of CD40-CD40L interactions strongly influences the onset and course in many autoimmune disease models including experimental autoimmune encephalomyelitis. We analysed the association of a single nucleotide polymorphism of the CD40 gene (C/T(-1)) in 287 patients with multiple sclerosis (MS) and 184 matched controls. No significant differences were found in the frequency of the C/T(-1) polymorphism between the patients with MS and the controls (53% vs 49%) or among different MS subtypes. Cell surface expression of CD40 did not differ within the different genotypes, but carriers of the T allele showed a trend for a lower stimulatory index compared with individuals with the CC genotype. Although these subtle differences indicate functional consequences in the immune stimulatory capabilities related to the CD40 C/T(-1) polymorphism, our population-based study found no association with disease susceptibility or disease course in MS.

Adolescent↗

PubMed2005

Development, validation, and evaluation of the PBC-40, a disease specific health related quality of life measure for primary biliary cirrhosis.

BACKGROUND AND AIMS: Study of health related quality of life (HRQOL) and the factors responsible for its impairment in primary biliary cirrhosis (PBC) has, to date, been limited. There is increasing need for a HRQOL questionnaire which is specific to PBC. The aim of this study was to develop, validate, and evaluate a patient based PBC specific HRQOL measure. SUBJECTS AND METHODS: A pool of potential questions was derived from thematic analysis of indepth interviews carried out with 30 PBC patients selected to represent demographically the PBC patient population as a whole. This pool was systematically reduced, pretested, and cross validated with other HRQOL measures in national surveys involving a total of 900 PBC patients, to produce a quality of life profile measure, the PBC-40, consisting of 40 questions distributed across six domains. The PBC-40 was then evaluated in a blinded comparison with other HRQOL measures in a further cohort of 40 PBC patients. RESULTS: The six domains of PBC-40 relate to fatigue, emotional, social, and cognitive function, general symptoms, and itch. The highest mean domain score was seen for fatigue and the lowest for itch. The measure has been fully validated for use in PBC and shown to be scientifically sound. PBC patient satisfaction, measured in terms of the extent to which a questionnaire addresses the problems that they experience, was significantly higher for the PBC-40 than for other HRQOL measures. CONCLUSION: The PBC-40 is a short easy to complete measure which is acceptable to PBC patients and has significantly greater relevance to their problems than other frequently used HRQOL measures. Its scientific soundness, shown in extensive testing, makes it a valuable instrument for future use in clinical and research settings.

Adult↗

PubMed2003

Admission as a dental student to the former UMDS and its relationship to socio-demographic characteristics.

OBJECTIVES: To describe the socio-demographic characteristics of successful and unsuccessful applicants to one UK dental school over a period of five years. To compare the characteristics of successful and unsuccessful candidates. DESIGN: Retrospective analysis of admissions data for the former United Medical and Dental Schools of Guy's and St Thomas' (UMDS) dental school provided by Universities and Colleges Admissions Service (UCAS) for a five year period (1994-1998). PARTICIPANTS: Applicants to the former UMDS dental school between 1994 and 1998. MAIN OUTCOME MEASURES: Success of candidates at four stages of the application process: initial application; offer made by the dental school; offer accepted or declined by the candidate; candidate accepted by the school (post A level results). Comparisons were made of the success rates among candidates grouped according to socio-demographic characteristics at each transition between these stages. A level performance was not included in the analysis, which must limit the findings, and may explain some of the variation found in the study. RESULTS: The effect of socio-demographic characteristics on the admissions process was small though significant. Approximately 9% of initial applicants reached the final stage and were accepted into the dental school. The most marked effect was a bias towards female entrants (11.5% of women applicants were accepted, compared with 7% of men). Only 5% of applicants from all the Black minority groups were successful. In comparison 17% of applicants of Chinese origin were successful. The proportion of accepted applicants from London and the South East (12%) was greater than from other areas (9%). CONCLUSIONS: Any conclusions must be tempered by the limitations of the study: the retrospective nature of the study together with the lack of information on A level results. Given these caveats, this study has demonstrated that the success of applicants to one former dental school was related to their socio-demographic characteristics. A prospective study including a number of dental schools in the UK which records both predicted and achieved A level grades would provide more definitive information on the impact of socio-demographic factors on admission to dental school.

Adolescent↗

PubMed2003

Potential and limitations of the automatic detection of fiducial markers using an amorphous silicon flat-panel imager.

Amorphous silicon electronic portal imaging devices (a-Si EPIDs) allow fast acquisition of high resolution portal images (PI). A visualization of organ movement for adaptive image-guided radiotherapy (IGRT) can be reached by implantation and automatic detection of fiducial markers. A method of automatic detection has been developed for fiducial spherical tungsten markers on PIs, acquired with an a-Si flat-panel imager. The detection method consists of a 2D Mexican hat filter (MHF), whose parameters are tuned to the particular marker signal. The high selectivity of this filter allows a reliable and precise detection of tungsten markers down to a diameter of 1.5 mm. The presented method allows fast, automatic and unsupervised detection of markers. Inevitably, the detection is hampered by image background (bone structures, etc) and noise. A detection success rate higher than 95% was reached, analysing PIs of patients with markers fixed on their skin. Furthermore, this approach to automatic marker detection can also be generalized to elliptic MHFs for the detection of cylindrical markers. The accuracy and detection probability of this method may allow accurate and fast online localization of the considered organ.

Feasibility Studies↗

PubMed2001

Recombinant human acidic fibroblast growth factor and fibrin carrier regenerates bone.

Bone regeneration promoted by acidic recombinant human fibroblast growth factor (rhFGF-1), rabbit demineralized bone matrix (rDBM), and a fibrin (f) delivery system was measured in critical-sized defects in rabbits' radii. A unilateral segmental defect 20 mm in length was prepared in radii of 48 skeletally mature New Zealand White rabbits divided equally between 4- and 8-week cohorts. The temporal cohorts were divided equally among four treatment groups: rDBM, rDBM/f, rDBM/rhFGF-1/f, and rhFGF-1/f. Data for the fifth group, untreated critical-sized defects, were exploited from previous published reports from this laboratory. In response to experimental treatments, radiomorphometric and histomorphometric methods were used to derive quantitative outcome data that were tested by analysis of variance and post hoc multiple comparison tests (significance p </= 0.05). Radiomorphometric data (percentage of radiopacity of defect) were acquired at the day of the operation and every 2 weeks thereafter, whereas histomorphometric data (square millimeters of new bone formation) were determined at term. The objective for the study was to develop candidate bone regenerative therapies. Therefore, the hypotheses were that experimental treatments would promote bone formation within critical-sized defects and that one treatment would be superior to the rest. Testing hypotheses was achieved with quantitative methodology, and data were subjected to statistical models. Radiopacity at each 2-week period was greater in treated defects than in untreated critical-sized defects. The amount of radiopacity promoted by rDBM/f and rhFGF-1/f at 8 weeks was equivalent and was greater than antecedent times. Histomorphometric data analyses indicated that rDBM/f and rDBM evoked the same quantity of new bone formation at 4 weeks; by 8 weeks, all treatments except rDBM/f had more new bone within the critical-sized defects in comparison to untreated defects. That rDBM/f promoted less new bone than rDBM alone may suggest fibrin decreases bone formation, perhaps by impeding local solubility of endogenous and rDBM-containing signaling molecules. However, rhFGF-1/f promoted a significant and unexpected increase in bone formation response that could refute the previous notion. In conclusion, the combination of rDBM/rhFGF-1/f may represent a significant, new osteogenic therapeutic regimen. Additional assessments in higher order species must be accomplished to corroborate efficacy.

Animals↗

PubMed2001

The privatisation of NHS dentistry? A national snapshot of general dental practitioners.

There is a prevalent perception that NHS dental treatment is increasingly difficult to access. In order to access the validity of this perception data on the percentage of private and NHS patients treated by general dental practitioners (GDPs) were analysed. These data were derived from a national survey. The findings showed that GDPs can be divided into three broad groups on the basis of the proportion of patients treated privately or through the National Health Service (NHS). Approximately 50% of GDPs nationally concentrate on NHS dentistry (85% or more of their patients are treated under the NHS); 25% treat more than 70% of their patients privately; the remaining minority of practitioners fall between these two positions treating moderate proportions of both private and NHS patients. Regional differences also exist in the payment systems chosen by GDPs. The median percentage of private patients per dentist varies widely by area being around 50% in the South East and South West, 30% in London, 20% in the West Midlands and Eastern counties and less than 10% elsewhere. In a multivariate regression GDP characteristics were also significant in explaining the median percentage of private patients per GDP The findings add to widely held concerns about access to NHS dentistry, though suggest that problems may be limited to certain areas of the United Kingdom.

Analysis of Variance↗

PubMed2001

Pavlovian conditioning-specific increases of the Ca2+- and GTP-binding protein, calexcitin in identified Hermissenda visual cells.

Hermissenda CNS, immunolabeled for the memory protein calexcitin showed significant immunostaining over background in the B-photoreceptor cells of the eye. The degree of staining correlated positively with the number of Pavlovian training events experienced by the animals and the degree of Pavlovian conditioning induced. The training regime consisted of exposing animals to light (conditioned stimulus, CS) paired with orbital rotation (unconditioned stimulus, US). In animals that exhibited the conditioned response, calexcitin immunolabeling was more intense than was found for naive (unconditioned) animals or animals given the CS and US in random sequence. Animals exposed to lead (maintained in 1.2 ppm lead acetate) at a dosage known to impair learning in children, showed reduced learning and less intense calexcitin staining whether the CS and US were paired or given randomly. However, the levels were still higher than that of naive animals. Immuno-electron microscopy indicated that the labeling was predominantly within calcium sequestering organelles such as the endoplasmic reticulum, and to lesser extent within mitochondria, and photopigments. The calexcitin density after a short-term memory (STM) regime was the same whether measured 5 minutes after conditioning (when STM was evidenced by foot contraction) or 90 minutes later when no recall was detected. The staining density was also similar to the levels found 5 minutes after long-term memory (LTM) conditioning. However, the LTM regime produced a greater calexcitin intensity at 90 minutes when the memory had been consolidated. This learning-specific increase in calexcitin is consistent with the previously implicated sequence of molecular events that are associated with progressively longer time domains of memory storage.

Animals↗

PubMed2001

The quality of life of older people with epilepsy: findings from a UK community study.

The impact of epilepsy on the quality of life of older people with epilepsy has rarely been investigated. As part of a large prevalence study of epilepsy conducted in one UK Health Region, we investigated the burden of their condition in older compared with younger people. A second analysis compared quality of life in those men and women diagnosed after the age of retirement from the workforce compared with those diagnosed before that age. Data were collected from men and women with epilepsy and from their primary and secondary care physicians. There were few differences between older and younger people with regard to their reported quality of life, though younger people were more likely to report feeling stigmatized by their condition. Older people with epilepsy diagnosed in later life were more anxious and depressed than those diagnosed earlier and their overall perception of quality of life was more likely to be negative. Our data emphasize that older people do not necessarily experience poorer quality of life than younger people, but those first diagnosed in later life do appear to have a quality of life which is more impaired. Consideration should be paid to the important psychosocial consequences of epilepsy in the older person.

Age Factors↗

PubMed2001

Hev b 7 is a Hevea brasiliensis protein associated with latex allergy in children with spina bifida.

BACKGROUND: In addition to their disease-associated handicaps, patients with spina bifida (SB) are at high risk of developing latex allergy. Individuals with SB represent a special group of latex-allergic patients, inasmuch as their IgE-binding patterns differ from those of other populations of latex-allergic individuals. Two allergens strongly associated with latex allergy in patients with SB--Hev b 1 and Hev b 3--have already been identified. OBJECTIVE: We intended to identify a predominant IgE-binding band--in addition to Hev b 1 and 3--at 43 kDa in a study population of 38 latex-allergic (IgE antibodies to latex and symptoms on provocation with latex gloves) and 15 latex-sensitized (IgE antibodies to latex but no symptoms on provocation) children with SB (mean age, 12.3 years) and to determine its frequency of recognition. METHODS: Sera of latex-sensitized or latex-allergic patients with SB were tested on latex C extract containing natural Hev b 1, Hev b 3, and Hev b 7 and with the recombinant 43-kDa Hev b 7 in immunoblot and inhibition studies. RESULTS: Natural Hev b 1 was recognized by 82% and natural Hev b 3 by 79% of the latex-allergic children with SB. In addition to some other proteins, 15 (39.5%) of 38 latex-allergic and 2 (13%) of 5 latex-sensitized children with SB revealed IgE binding to a 43-kDa band in the latex protein extract. We identified this 43-kDa IgE-binding band as natural Hev b 7 by immunoblotting and inhibition experiments using recombinant Hev b 7. CONCLUSION: From these data, we conclude that Hev b 7, the patatin-like Hevea latex protein, is the third SB-associated latex allergen. Future immunotherapy for latex-allergic individuals with SB will have to include Hev b 7 in addition to Hev b 1 and Hev b 3.

Adolescent↗

PubMed2001

Smoking and quitting with the aid of nicotine replacement therapies in the English adult population. Results from the Health Education Monitoring Survey 1995.

BACKGROUND: Many clinical trials have shown the usefulness of nicotine replacement therapies, family physician advice and other cessation aids in enhancing smoking cessation. However, many trials have taken place amongst selected patients and doctors. This paper assesses cessation amongst a representative general adult population in England in order to see whether such aids are as successful amongst more typical smokers. METHODS: Descriptive information on the pattern of smoking cessation aids use in the English population is presented for the first time. This is followed by multivariate probit analysis of the 'Health in England 1995' survey data set in order to predict successful smoking cessation as a function of several variables including use of nicotine gum and patches, willpower, advice from family physicians, social class, education, gender, marital status and family composition. RESULTS: The results tend to confirm that lower social class and lower educational achievement are linked to continuing smoking status. However, users of nicotine gum and patches were found to be less likely to have given up smoking than non-users. This may be explained by the fact that only those who find it difficult to give up will go to the time and expense of considering such aids. These findings could also be explained by the fact that gum and patches have only been available recently in England. The pattern of results also suggests that 'willpower' is a marker for success in cessation as opposed to a determinant of giving up in its own right. CONCLUSION: This research confirms a lot of other research on the determinants of smoking cessation and has for the first time looked at the use and impact of nicotine replacement therapy on giving up in a representative English adult population. More research is needed on observational data sets in order to tease out the true impact of nicotine replacement on cessation rates in representative smoking populations.

Adolescent↗

PubMed2001

Costs of dementia in England and Wales in the 21st century.

BACKGROUND: An important factor determining future health care expenditure is the relationship between ageing, health status and development of age-related disorders such as dementia. AIMS: To estimate the formal care costs associated with dementia in England and Wales between 1994 and 2031. METHOD: Epidemiological cost model, applied to individuals aged 65 years or over with dementia, using estimates of life expectancy with dementia and dementia-free life expectancy. RESULTS: Total costs per year were pound 0.95 billion (men) and pound 5.35 billion (women) using 1994 population estimates. For 2031, costs were pound 2.34 billion and pound 11.20 billion, respectively. Reduced dementia prevalence rates and improvements in mental and physical functioning resulted in lower estimates: pound 1.01 billion (men) and pound 5.77 billion (women), and pound 1.65 billion (men) and pound 7.87 billion (women), respectively. CONCLUSIONS: Future increases in the population aged 65 years or over lead to rising formal care costs. However, the magnitude of cost changes depends on assumptions over dementia prevalence and levels of mental and physical functioning.

Aged↗

PubMed2001

Non-clinical outcome measures in dentistry: publishing trends 1988-98.

OBJECTIVES: To provide an overview of the use of non-clinical outcome measures in dentistry and to identify trends and strengths and weaknesses in existing research. METHODS: Literature searches using medical and social sciences databases and stated inclusion and exclusion criteria. Categorisation and coding of accepted studies according to: concept of outcome, study design and standardisation of outcome measures used. Simple graphical and statistical analysis used to identify trends in outcome measurement and strengths and weaknesses. RESULTS: There has been a steady growth in non-clinical outcome measurement research in dentistry over the last 10 years. Most studies have addressed dental knowledge, attitudes or behaviours (KAB), socio-dental indicators or anxiety. Two-thirds of all studies have used non-standardised outcome measures. Different concepts of outcome are associated with different study designs and standardisation status of outcome measures used. Studies addressing dental "satisfaction" and KAB are more likely than average to use non-validated measures. CONCLUSIONS: There needs to be more focus on the development of methods to assess the validity of non-clinical outcome measures in dentistry. In addition more conceptual studies need to be undertaken on the theoretical links between the different concepts of outcome found in the current study.

Attitude of Health Personnel↗

PubMed2001

Workforce planning in dentistry: the impact of shorter and more varied career patterns.

OBJECTIVE: To compare the frequency and duration of career breaks taken by three groups of dental health care professionals and to assess the impact of these and changes in working hours on human resource planning. BACKGROUND: Dental personnel planning has been the subject of recent attention, particularly the role of professionals complementary to dentistry. Data on which to plan a dental personnel strategy have been lacking. METHOD: Questionnaire survey of a random sample of 10% of dental practitioners, and of all dental therapists and dental hygienists registered with the General Dental Council. The proportion of each group who had taken a career break at some point during their career was analysed for each professional group. RESULTS: A larger proportion of female general dental practitioners (61%) than male practitioners (27%) take a break in their career at some point during their working lives. The proportion of hygienists who take career breaks is similar (57%) to the proportion of female GDPs. The proportion of dental therapists who take a career break (who in this sample were all female) is 71%. The duration of career breaks taken by women is longer than that for males, the median length of career breaks for male dental practitioners is 4 months; female dental practitioners 9 months; hygienists 11 months; therapists 11.5 months. Female GDPs who take a career break can be expected to have a working life 25% shorter than a GDP who does not take a career break. CONCLUSIONS: As the proportion of female general dental practitioners increases, and with the possible expansion of the role of professionals complementary to dentistry, there is likely to be an increase in the proportion of dental personnel who take a career break during their working lives. Planning of dental personnel requirements should consider the likely effect of career breaks upon the availability of dental staff.

Adult↗

PubMed2000

What makes a good dentist and do recent trainees make the grade? The views of vocational trainers.

OBJECTIVE: The aim of this paper is to examine the factors that vocational trainers regard as important in a 'good' dentist and to assess whether they think recent graduates were achieving these factors. DESIGN: The study was based on a statistical analysis of returns from a postal questionnaire. SETTING: Postal questionnaires were sent to all vocational advisors in England who then sent them on to a number of their vocational trainers. MATERIALS AND METHODS: The questionnaire was analysed using various statistical techniques including factor analysis. Analysis was undertaken to determine whether student or trainer characteristics influenced the trainer's responses. RESULTS: The vocational trainers judged that the group of skills that contribute to technical ability are the most important component in making a 'good' dentist. However, the most important single skill is communication with patients, closely followed by diagnostic skills and communication with the dental team. The areas where trainees are most likely to fall short in terms of actual as compared to desired performance are in areas of technical ability. CONCLUSION: Overall, recent trainees scored rather well when compared with an idealised good dentist. However, it is clear that more evaluation of vocational training is needed. Recent studies, including this one have looked at several different aspects of vocational training. However, the time seems ripe for a full-scale prospective evaluation.

Attitude of Health Personnel↗

PubMed2000

Geometry of site alignment during int family recombination: antiparallel synapsis by the Flp recombinase.

The Flp site-specific recombinase functions in the copy number amplification of the yeast 2 microm plasmid. The recombination reaction is catalyzed by four monomers of Flp bound to two separate, but identical, recombination sites (FRT sites) and occurs in two sequential pairs of strand exchanges. The relative orientation of the two recombination sites during synapsis was examined. Topoisomerase relaxation and nick ligation were used to detect topological nodes introduced by the synapse prior to the chemical steps of recombination. A single negative supercoil was found to be trapped by Flp in substrates with inverted FRT sites whereas no trapped supercoils were observed with direct repeats. The topology of products resulting from Flp-mediated recombination adjacent to a well characterised synapse, that of Tn3 resolvase/res, was analyzed. The deletion and inversion reactions yielded the four noded catenane and the three noded knot, respectively, as the simplest and the most abundant products. The linking number change introduced by the Flp-mediated inversion reaction was determined to be +/-2. The most parsimonious explanation of these results is that Flp aligns its recombination sites with antiparallel geometry. The majority of synapses appear to occur without entrapment of additional random plectonemic DNA supercoils between the sites and no additional crossings are introduced as a result of the chemical steps of recombination.

Binding Sites↗

PubMed2000

Functionally defined CD164 epitopes are expressed on CD34(+) cells throughout ontogeny but display distinct distribution patterns in adult hematopoietic and nonhematopoietic tissues.

Three distinct classes of epitopes on human CD164 have been identified. Two of these, recognized by the monoclonal antibodies 105A5 and 103B2/9E10, are the CD164 class I and class II functionally defined epitopes, which cooperate to regulate adhesion and proliferation of CD34(+) cell subsets. In this article, we demonstrate that these 2 CD164 epitopes are expressed on CD34(+) cells throughout ontogeny, in particular on CD34(+ )cell clusters associated with the ventral floor of the dorsal aorta in the developing embryo and on CD34(+) hematopoietic precursor cells in fetal liver, cord blood, and adult bone marrow. While higher levels of expression of these CD164 epitopes occur on the more primitive AC133(hi)CD34(hi)CD38(lo/-) cell population, they also occur on most cord blood Lin(-)CD34(lo/-)CD38(lo/- )cells, which are potential precursors for the AC133(hi)CD34(hi)CD38(lo/-) subset. In direct contrast to these common patterns of expression on hematopoietic precursor cells, notable differences in expression of the CD164 epitopes were observed in postnatal lymphoid and nonhematopoietic tissues, with the class I and class II CD164 epitopes generally exhibiting differential and often reciprocal cellular distribution patterns. This is particularly striking in the colon, where infiltrating lymphoid cells are CD164 class I-positive but class II-negative, while epithelia are weakly CD164 class II-positive. Similarly, in certain lymphoid tissues, high endothelial venules and basal and subcapsular epithelia are CD164 class II-positive, while lymphoid cells are CD164 class I-positive. It therefore seems highly likely that these CD164 class I and II epitopes will mediate reciprocal homing functions in these tissue types.

Adult↗

PubMed2000

Characterization of T cell responses to Hev b 3, an allergen associated with latex allergy in spina bifida patients.

The prevalence of type I allergy to Hevea brasiliensis latex is particularly high among individuals with frequent exposure such as health care workers and patients with spina bifida (SB). Due to a birth defect of the spinal canal and the resulting neurological and orthopedic defects, these patients require multiple surgeries during childhood. SB patients display a unique pattern of sensitization: IgE-reactivity is preferentially directed against Hev b 3 and Hev b 1, two latex allergens with high sequence similarity. In this study, we analyzed the T cell response to Hev b 3 in latex-allergic SB patients using poly-, oligo-, and monoclonal T lymphocyte cultures. All T cell clones (TCC) were CD3/CD4-positive and expressed the alphabeta TCR. According to their cytokine production pattern (IL-4 vs IFN-gamma), 12 of 21 TCC were classified as Th2-like, 2 of 21 were Th1-like, and 7 of 21 belonged to a Th0-like subset. Using 11 T cell lines and 21 TCC, nine T cell stimulating fragments were determined out of 52 overlapping 12-mer peptides representing the complete amino acid sequence of Hev b 3. Ag presentation of one dominant T cell epitope could be associated with a four-amino acid binding motif (YSTS, position 11-13) in the beta 1 chain of HLA-DR molecules expressed by the respective patients. No reactivity was observed when Hev b 3-reactive T cell lines or TCC were incubated with peptides representing homologous parts of the Hev b 1 molecule, i.e., no cross-reactivity between Hev b 3 and Hev b 1 at the T cell level was evident.

Allergens↗