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.     

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.     

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.     

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.     

Incomplete rescue of cystic fibrosis transmembrane conductance regulator deficient mice by the human CFTR cDNA

We have used a mouse model to study the ability of human CFTR to correct the defect in mice deficient of the endogenous protein. In this model, expression of the endogenous Cftr gene was disrupted and replaced with a human CFTR cDNA by a gene targeted 'knock-in' event. Animals homozygous for the gene replacement failed to show neither improved intestinal pathology nor survival when compared to mice completely lacking CFTR. RNA analyses showed that the human CFTR sequence was transcribed from the targeted allele in the respiratory and intestinal epithelial cells. Furthermore, in vivo potential difference measurements showed that basal CFTR chloride channel activity was present in the apical membranes of both nasal and rectal epithelial cells in all homozygous knock-in animals examined. Ussing chamber studies showed, however, that the cAMP-mediated chloride channel function was impaired in the intestinal tract among the majority of homozygous knock-in animals. Hence, failure to correct the intestinal pathology associated with loss of endogenous CFTR was related to inefficient functional expression of the human protein in mice. These results emphasize the need to understand the tissue- specific expression and regulation of CFTR function when animal models are used in gene therapy studies.      

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.     

Extreme heterogeneity in CARD15 and DLG5 Crohn disease-associated polymorphisms between German and Norwegian populations

The first gene associated with Crohn disease (CD) has been identified as CARD15 (16q12). Three variants, R702W, G908R and 1007fsinsC are strongly and independently associated with the disease. A second gene, conveying a smaller risk for inflammatory bowel disease (IBD), has been identified as DLG5 (10q23). We assess the frequency of the CARD15 SNPs and of the R30Q mutation in DLG5 and their contribution to the development of CD in a cohort of unrelated IBD patients (151 CD, 325 ulcerative colitis (UC)) and healthy controls (236) from South-east Norway (IBSEN cohort). Genotype-based tests of population differentiation using 23 SNPs across CARD15, together with estimates of F(ST), indicated that the German and Norwegian background populations could be differentiated at the CARD15 locus. The Norwegian and German CD samples exhibited particularly strong differentiation at the three predisposing loci and those marking their background haplotype. There were significantly lower frequencies of the CARD15 SNPs and no significant association with CD in the Norwegian samples. Only a marginal association was observed for the subphenotypes ileitis and ileocolitis vs colitis (P=0.048). The population attributable risk percentage (PAR%) for CARD15 variants in the Norwegian cohort is the lowest reported for a European population (1.88%), except Iceland. Similarly, the DLG5 variant showed no association with CD or IBD, however, there was a negative correlation with stricture (P=0.035). The present results are consistent with an emerging pattern of a low frequency of the CARD15 variants in Northern countries where the prevalence of IBD is greatest.     

IgG subclass antibodies to serogroup B meningococcal outer membrane antigens following infection and vaccination

IgG and IgG subclass antibodies to the outer membrane antigens from Neisseria meningitidis (serogroup B, serotype 15:P1.16) were quantitated by an enzyme-linked immunosorbent assay (ELISA) in sera from 40 patients with group B:15:P1.16 meningococcal disease and 24 volunteers immunized with a serotype 15:P1.16 outer membrane vesicle vaccine. A second injection was given 6 weeks after the first immunization. Patient sera obtained two and six weeks after onset of the disease had significantly higher levels of total IgG, IgG1, IgG2, and IgG3 antibodies to the outer membrane antigens than acute sera, convalescent sera from patients with systemic non-meningococcal bacterial infections and sera from healthy controls. The levels of total IgG and IgG1 remained high one and three years later. Sera from the vaccinees showed high levels of total IgG and IgG1 6, 12 and 26 weeks after the first immunization and high levels of IgG3 6 weeks after the second immunization. No increase of IgG2 or IgG4 levels was observed in the postimmunization sera. Immunoblotting of three convalescent sera demonstrated individual patterns of IgG subclass binding to various outer membrane antigens with most distinct binding of IgG1 and IgG3 antibodies to the class I protein, the H.8 lipoprotein and the lipopolysaccharide. Since IgG1 and IgG3 are the most effective antibodies for complement activation and phagocytosis, group B meningococcal disease and immunization with the serotype 15:P1.16 outer membrane vesicle vaccine stimulate production of those IgG subclasses which have the strongest opsonic and bactericidal activity.     

Gentamicin therapy of severe infections

Summary Gentamicin was administered to 32 patients with severe infections due to gram-negative bacilli, 17 caused byPseudomonas aeruginosa. Fourteen of the 32 patients had major underlying diseases, and three patients had been unsuccessfully treated with carbenicillin or cephalothin prior to gentamicin therapy.Thirteen of the 17 patients with septicemia were cured, six of eight patients with respiratory tract infections and four of seven patients with wound infections. In addition to gentamicin, six patients who were cured also received carbenicillin, cephalothin or ampicillin. Therapeutic failure could be attributed to major underlying noninfectious diseases, undrained abscesses, profound granulocytopenia, pronounced shock or superinfection.Gentamicin was well tolerated. Two patients developed transient azotemia and one patient superinfection withCandida species.Gentamicin is a valuable drug in the therapy of severe gram-negative infections.

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Gentamicintherapie bei schweren Infektionen

Zusammenfassung Zweiunddreißig Patienten mit schweren, durch gramnegative Bakterien verursachten Infektionen wurden mit Gentamicin behandelt, 17 Fälle davon wurden durch Ps. aeruginosa verursacht. Vierzehn der 32 Patienten hatten schwere Grundleiden, und drei Patienten wurden ohne Erfolg mit Carbenicillin oder Cephalotin vorbehandelt.Dreizehn der 17 Patienten mit Sepsis wurden geheilt, sechs von acht Patienten mit Infektionen der Atemwege und vier von sieben Patienten mit Wundinfektionen. Zusätzlich zu Gentamicin erhielten sechs der Patienten auch Carbenicillin, Cephalotin oder Ampicillin. Therapieversager traten bei den schweren Grundleiden, bei einem nicht drainierten Abszeß, bei einer Granulozytopenie, bei einem fortgeschrittenen Schock und bei Superinfektionen auf.Das Gentamicin wurde gut vertragen. Bei zwei Patienten entwickelte sich eine Harnstofferhöhung und bei einem eine Superinfektion mit Candida.Gentamicin ist als ein wertvolles Therapeutikum zur Behandlung von schweren gramnegativen Erregern verursachten Infektionen anzusehen.