Epidermal growth factor receptor - but not histamine receptor - is upregulated in seasonal allergic rhinitis

BACKGROUND: We were interested in exploring the molecular mechanisms underlying the observed difference in histamine (H) responsiveness between seasonal allergic rhinitic (SAR) and nonrhinitic (NR) subjects. We hypothesized that SAR subjects express higher nasal mucosal histamine receptor 1 (H1R) and 2 (H2R) levels than do NR subjects. In addition, we examined expression of genes involved in regulating the glandular response, including epidermal growth factor (EGF), EGF receptor (EGFR), and mucins (Muc5Ac and Muc5B). METHODS: Fourteen subjects, seven SAR and seven NR, were provoked during pollen season with doubling doses of H (0.125-8.0 mg/ml). Nasal airway resistance (NAR) was measured by active posterior rhinomanometry. Provocation was halted when NAR exceeded 150% of baseline. Prior to provocation, nasal scrapings were obtained and mRNA quantified using two-step real-time PCR. RESULTS: The mean PD50 (concentration of H producing a 50% increase in NAR) was significantly lower in the SAR than NR group (0.36 vs 1.32 mg/ml; P < 0.05). The ratio of relative gene copy numbers between the SAR and NR groups were as follows: H1R, 0.85 (P = 0.52); H2R, 0.67 (P = 0.35); EGF, 1.02 (P = 0.93), and EGFR, 103.5 (P < 0.05). CONCLUSIONS: There were no significant differences in H1R or H2R mRNA levels between SAR and NR subjects in-season, despite observed differences in H reactivity. SAR subjects, however, did show a significant elevation in EGFR expression, consistent with the observation of mucus hypersecretion in allergic rhinitis.     

Incorporating and evaluating an integrated gender-specific medicine curriculum: a survey study in Dutch GP training

Background  

We recently set standards for gender-specific medicine training as an integrated part of the GP training curriculum. This paper describes the programme and evaluation of this training.     

Lineage is an Epigenetic Modifier of QTL Influencing Behavioral Coping with Stress

A genome-wide scan was carried out on a segregating F2 population of rats derived from reciprocal intercrosses between two inbred strains of rats, Fisher 344 (F344) and Wistar Kyoto (WKY) that differ significantly in their behavioral coping responses to stress measured by the defensive burying (DB) test. The DB test measures differences in coping strategies by assaying an animals behavioral response to an immediate threat. We have previously identified three X-linked loci contributing to the phenotypic variance in behavioral coping. Here we report on six significant autosomal quantitative trait loci (QTL) related to different behaviors in the DB test:one for the number of shocks received, three for number of prod approaches, one for latency to bury, and one pleiotropic locus affecting both approach and latency. These QTL contributing to different aspects of coping behaviors show that the effect of genotype on phenotype is highly dependent on lineage. The WKY lineage was particularly influential, with five out of the six QTL affecting coping behavior only in rats of the WKY lineage, and one locus affecting only those in the F344 lineage. Thus, epigenetic factors, primarily of WKY origin, may significantly modulate the genetic contribution to variance in behavioral responses to stress in the DB test.     

Targeting accuracy of an image guided gating system for stereotactic body radiotherapy

Recently, a commercial system capable of x-ray image guided patient positioning and respiratory gated delivery has become available. Here we describe the operational principles of this system and investigate its geometric targeting accuracy under controlled conditions. The system tracks breathing via infrared (IR) detection of reflective markers located on the patient's abdomen. Localization kilovoltage (kV) x-rays are triggered from within the gated delivery window portion of the breathing trace and after positioning, the tumour will cross the linac isocentre during gated delivery. We tested geometric accuracy of this system by localizing and delivering gated fields to a moving phantom. Effects of phantom speed, gating window location, timing errors and phantom rotations on positioning and gating accuracy were investigated. The system delivered gated fields to both a moving and static phantom with equal accuracy. The position of the gating window affects accuracy only to the extent that an asymmetric breathing motion could affect dose distribution within its boundaries. Positioning errors were found to be less then 0.5 +/- 0.2 mm for phantom rotations up to 5 degrees. We found and corrected a synchronization error caused by a faulty x-ray duration setting and detected a 60 +/- 20 ms time delay in our linear accelerator.     

Experimental verification and clinical implementation of a commercial Monte Carlo electron beam dose calculation algorithm

This study describes the modeling and the experimental verification and clinical implementation of the alpha release of Pinnacle3 Monte Carlo (MC) electron beam dose calculation algorithm for patient-specific treatment planning. The MC electron beam modeling was performed for beam energies ranging from 6 to 18 MeV from a Siemens (Primus) linear accelerator using standard-shaped electron applicators and 100 cm source-to-surface distance (SSD). The agreement between MC calculations and measurements was, on average, within 2% and 2 mm for all applicator sizes. However, differences of the order of 3%-4% were noted in the off-axis dose profiles for the largest applicator modeled and for all energies. Output factors were calculated for standard electron cones and square cutouts inserted in the 10 x 10 cm2 applicator for different SSDs and were found to be within 4% of measured data. Experimental verification of the MC electron beam model was carried out using an ionization chamber and film in solid-water slab and anthropomorphic phantoms containing bone and lung materials. Agreement between calculated and measured dose distributions was within +/-3%. Clinical comparison was performed in four patient treatment plans with lesions in highly irregular anatomies, such as the ear, face, and breast, where custom-designed bolus and field shaping blocks were used in the patient treatments. For comparison purposes, treatment planning was also performed using the conventional pencil beam (PB) algorithm with the Pinnacle3 treatment planning system. Differences between MC and PB dose calculations for the patient treatment plans were significant, particularly in anatomies where the target was in close proximity to low density tissues, such as lung and air cavities. Concerning monitor unit calculations, the largest differences obtained between MC and PB algorithms were between 4.0% and 5.0% for two patients treated with oblique beams and involving highly irregular surfaces, i.e., breast and cheek. Clinical results are reported for overall uncertainty values (averaged over voxels with doses >50% dosemax) ranging from 2% to 0.3% and calculations were performed using cubic voxels with side 0.3 cm. Timing values ranged from 2 min to 24.5 h, depending on the field size, beam energy, number, and thickness of computed tomography slices used to define the patient's anatomy for the overall uncertainty values mentioned above.     

High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes

As more mutations are identified in genes of known sequence, there is a crucial need in the areas of medical genetics and genome analysis for rapid, accurate and cost-effective methods of mutation detection. We have developed a multiplex allele-specific diagnostic assay (MASDA) for analysis of large numbers of samples (> 500) simultaneously for a large number of known mutations (> 100) in a single assay. MASDA utilizes oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA samples are immobilized on a solid support and a single hybridization is performed with a pool of allele-specific oligonucleotide (ASO) probes. Any probes complementary to specific mutations present in a given sample are in effect affinity purified from the pool by the target DNA. Sequence-specific band patterns (fingerprints), generated by chemical or enzymatic sequencing of the bound ASO(s), easily identify the specific mutation(s). Using this design, in a single diagnostic assay, we tested samples for 66 cystic fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations, four mutations in Canavan disease, four mutations in Fanconi anemia, and five mutations in BRCA1. Each mutation was correctly identified. Finally, in a blinded study of 106 of these mutations in > 500 patients, all mutations were properly identified. There were no false positives or false negatives. The MASDA assay is capable of detecting point mutations as well as small insertion or deletion mutations. This technology is amenable to automation and is suitable for immediate utilization for high-throughput genetic diagnostics in clinical and research laboratories.      

Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1

The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X- linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.      

The long-term effectiveness of generic adult fixed-dose combination antiretroviral therapy for HIV-infected Ugandan children

Background

Access to pediatric antiretroviral formulations is increasing in resource-limited countries, however adult FDCs are still commonly used by antiretroviral therapy (ART) programs.

Objective

To describe long-term effectiveness of using adult FDC of d4T+3TC+NVP (Triomune) in children for HIV treatment.

Methods

Clinical, immunologic, and virologic outcomes of HIV-infected ART-naïve children aged six months to 12 years, were evaluated up to 96 weeks post-ART initiation.

Results

From March 2004 to June 2006, 104 children were followed with a median age of 5.4 years, median CD4 cell percent and HIV-1 RNA were 11.0% (IQR 6.7–13.9) and 348,846copies/mL (IQR 160,941–681,313) respectively at baseline. Using Kaplan-Meir estimates, 75% of children had undetectable viral loads (<400copies/mL) at 96weeks of ART. Children with a baseline CD4 cell percent >15% were 3 times more likely to achieve viral load <400copies/mL than those with baseline CD4 cell percent <5% after adjusting for baseline age {aHR = 3.03 (1.10–8.32), p=0.03}; no difference was found among those with CD4 cell percent >5–14.9% and <5%.

Conclusion

Treatment with generic adult FDC for HIV-infected Ugandan children led to sustained clinical, immunologic and virologic response during 96 weeks of ART. Early initiation of ART is key to achieving virological success.     

Multichannel detectors for profile measurements in clinical proton fields

Two beam profile measurement detectors have been developed at Indiana University Cyclotron Facility to address the need for a tool to efficiently verify dose distributions created with active methods of clinical proton beam delivery. The multipad ionization chamber (MPIC) has 128 ionization chambers arranged in one plane and is designed to measure lateral profiles in fields up to 38 cm in diameter. The MPIC pads have a 5 mm pitch for fields up to 20 cm in diameter and a 7 mm pitch for larger fields, providing the accuracy of field size determination about 0.5 mm. The multilayer ionization chamber (MLIC) detector contains 122 small-volume ionization chambers stacked at a 1.82 mm step (water-equivalent) for depth-dose profile measurements. The MLIC detector can measure profiles up to 20 cm in depth, and determine the 80% distal dose fall-off with about 0.1 mm precision. Both detectors can be connected to the same set of electronics modules, which comprise the detectors' data acquisition system. The detectors have been tested in clinical proton fields produced with active methods of beam delivery such as uniform scanning and energy stacking. This article describes detector performance tests and discusses their results. The test results indicate that the MPIC and MLIC detectors can be used for dosimetric characterization of clinical proton fields. The detectors offer significant time savings during measurements in actively delivered beams compared with traditional measurements using a water phantom.     

Broad consent versus dynamic consent in biobank research: Is passive participation an ethical problem?

In the endeavour of biobank research there is dispute concerning what type of consent and which form of donor–biobank relationship meet high ethical standards. Up until now, a ‘broad consent'' model has been used in many present-day biobank projects. However it has been, by some scholars, deemed as a pragmatic, and not an acceptable ethical solution. Calls for change have been made on the basis of avoidance of paternalism, intentions to fulfil the principle of autonomy, wish for increased user participation, a questioning of the role of experts and ideas advocating reduction of top–down governance. Recently, an approach termed ‘dynamic consent'' has been proposed to meet such challenges. Dynamic consent uses modern communication strategies to inform, involve, offer choices and last but not the least obtain consent for every research projects based on biobank resources. At first glance dynamic consent seems appealing, and we have identified six claims of superiority of this model; claims pertaining to autonomy, information, increased engagement, control, social robustness and reciprocity. However, after closer examination, there seems to be several weaknesses with a dynamic consent approach; among others the risk of inviting people into the therapeutic misconception as well as individualizing the ethical review of research projects. When comparing the two models, broad consent still holds and can be deemed a good ethical solution for longitudinal biobank research. Nevertheless, there is potential for improvement in the broad model, and criticism can be met by adapting some of the modern communication strategies proposed in the dynamic consent approach.