Diversity in auxology: between theory and practice. Proceedings of the 18th Aschauer Soiree, 13th November 2010

Auxology has developed from mere describing child and adolescent growth into a vivid and interdisciplinary research area encompassing human biologists, physicians, social scientists, economists and biostatisticians. The meeting illustrated the diversity in auxology, with the various social, medical, biological and biostatistical aspects in studies on child growth and development.

First measurement of chiral dynamics in π- γ → π- π- π+

The COMPASS Collaboration at CERN has investigated the π- γ → π- π- π+ reaction at center-of-momentum energy below five pion masses, sqrt[s]<5m(π), embedded in the Primakoff reaction of 190 GeV pions impinging on a lead target. Exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, t'<0.001  GeV2/c2. Using partial-wave analysis techniques, the scattering intensity of Coulomb production described in terms of chiral dynamics and its dependence on the 3π-invariant mass m(3π)=sqrt[s] were extracted. The absolute cross section was determined in seven bins of sqrt[s] with an overall precision of 20%. At leading order, the result is found to be in good agreement with the prediction of chiral perturbation theory over the whole energy range investigated.

[Pericardial effusion. Differential diagnostics, surveillance and treatment]

Cardiac tamponade can be a life-threatening condition due to the high variability of clinical symptoms and the associated risk of rapid hemodynamic deterioration. Therefore, accurate diagnosis followed by immediate intervention is necessary. Common clinical features of cardiac tamponade are pulsus paradoxus, tachycardia, elevated jugular venous pressure and hypotension; however, although these can be indicative of cardiac tamponade they are non-specific. Instant confirmation of the clinical diagnosis of cardiac tamponade can be pursued with echocardiography which also enables a clear estimation of the current hemodynamic situation. Thus in contemporary clinical practice echocardiography plays a key role in the management of cardiac tamponade and must be consulted with regards to final treatment decisions. Common practice includes pericardial puncture under echocardiographic and/or X-ray guidance but only in cases of significantly sized pericardial effusions. Whenever there is a limited sized but hemodynamically significant effusion, inferior pericardiotomy should be the preferred treatment strategy. In cases of cardiac tamponade following chest trauma a full median sternotomy can be a suitable approach for surgical treatment.

Sequence of four orthogonal smectic phases in an achiral bent-core liquid crystal: evidence for the SmAP(α) phase

The mesomorphic properties of an achiral bent-core liquid crystal derived from 4-cyanoresorcinol are studied by polarizing optical microscopy, x-ray diffraction, and second harmonic electro-optic response. It shows a novel sequence of four nontilted or orthogonal smectic phases on cooling: SmA-SmAP(R)-SmAP(X)-SmAP(A). Here SmAP(X) is the new orthogonal polar uniaxial smectic phase. The electric-field-induced transformations in the SmAP(X) phase give rise to two biaxial states separated by a uniaxial one. The second harmonic electro-optic response in this phase is interpreted in terms of the polar interaction with the electric field. A comparison of the experimental results with the next-nearest-neighbor model for the structure of the SmAP(X) phase shows it to be an SmAP(α) phase.

Short-range correlations seen in the nematic phase of bent-core liquid crystals by dielectric and electro-optic studies

Three bent-core nematic liquid crystals having the same core but with different terminal groups, short (C4) and long (C7,C9) tails, are investigated by dielectric and electro-optic contrast spectroscopic techniques. C4 shows sign reversal in the dielectric anisotropy Δε' as a function of both temperature and frequency, whereas C9 shows only negative Δε' in the entire mesophasic region. The behavior of C7 is intermediate of the two. Results of a dielectric study show that both C7 and C9 exhibit strong short-range polar correlations normal to the director. The correlation lengths of these interactions are found to be similar to those from the x-ray scattering. An increased hindered rotation for C9 compared to C4 moves the dielectric dispersion for ε(|') to much lower frequencies, such that C9 shows only negative Δε' over the entire temperature range.

Review article: the role of gastric motility in the control of food intake

BACKGROUND

From a classical point of view, gastric motility acts to clear the stomach between meals, whereas postprandial motility acts to provide a reservoir for food, mixing and grinding the food and to assure a controlled flow of food to the intestines.

AIM

To summarise findings that support the role of gastric motility as a central mediator of hunger, satiation and satiety.

METHODS

A literature review using the search terms 'satiety', 'satiation' and 'food intake' was combined with specific terms corresponding to the sequence of events during and after food intake.

RESULTS

During food intake, when gastric emptying of especially solids is limited, gastric distension and gastric accommodation play an important function in the regulation of satiation. After food intake, when the stomach gradually empties, the role of gastric distension in the determination of appetite decreases and the focus will shift to gastric emptying and intestinal exposure of the nutrients. Finally, we have discussed the role of the empty stomach and the migrating motor complex in the regulation of hunger signals.

CONCLUSIONS

Our findings indicate that gastric motility is a key mediator of hunger, satiation and satiety. More specifically, gastric accommodation and gastric emptying play important roles in the regulation of gastric (dis)tension and intestinal exposure of nutrients and hence control satiation and satiety. Correlations between gastric accommodation, gastric emptying and body weight indicate that gastric motility can also play a role in the long-term regulation of body weight.

Effects of chronic weight perturbation on energy homeostasis and brain structure in mice

Maintenance of reduced body weight in lean and obese human subjects results in the persistent decrease in energy expenditure below what can be accounted for by changes in body mass and composition. Genetic and developmental factors may determine a central nervous system (CNS)-mediated minimum threshold of somatic energy stores below which behavioral and metabolic compensations for weight loss are invoked. A critical question is whether this threshold can be altered by environmental influences and by what mechanisms such alterations might be achieved. We examined the bioenergetic, behavioral, and CNS structural responses to weight reduction of diet-induced obese (DIO) and never-obese (CON) C57BL/6J male mice. We found that weight-reduced (WR) DIO-WR and CON-WR animals showed reductions in energy expenditure, adjusted for body mass and composition, comparable (-10-15%) to those seen in human subjects. The proportion of excitatory synapses on arcuate nucleus proopiomelanocortin neurons was decreased by ∼50% in both DIO-WR and CON-WR mice. These data suggest that prolonged maintenance of an elevated body weight (fat) alters energy homeostatic systems to defend a higher level of body fat. The synaptic changes could provide a neural substrate for the disproportionate decline in energy expenditure in weight-reduced individuals. This response to chronic weight elevation may also occur in humans. The mouse model described here could help to identify the molecular/cellular mechanisms underlying both the defense mechanisms against sustained weight loss and the upward resetting of those mechanisms following sustained weight gain.

Membrane Curvature Induced by Sugar and Polymer Solutions

We monitor the effect of transversal membrane asymmetry on the morphology of giant uni-lamellar vesicles in sugar and polymer solutions. The shapes of fluid lipid vesicles are governed by the bending elasticity of their membrane which is characterized by the bending modulus and the spontaneous curvature of the bilayer. We present a recently developed technique for the measurement of the spontaneous curvature using quantitative phase contrast microscopy. Different mechanisms for elastic membrane asymmetry and the role of the bending energy concept for the morphology of cellular organelles are discussed.

Recent advances into understanding some aspects of the structure and function of mammalian and avian lungs

Recent findings are reported about certain aspects of the structure and function of the mammalian and avian lungs that include (a) the architecture of the air capillaries (ACs) and the blood capillaries (BCs); (b) the pulmonary blood capillary circulatory dynamics; (c) the adaptive molecular, cellular, biochemical, compositional, and developmental characteristics of the surfactant system; (d) the mechanisms of the translocation of fine and ultrafine particles across the airway epithelial barrier; and (e) the particle-cell interactions in the pulmonary airways. In the lung of the Muscovy duck Cairina moschata, at least, the ACs are rotund structures that are interconnected by narrow cylindrical sections, while the BCs comprise segments that are almost as long as they are wide. In contrast to the mammalian pulmonary BCs, which are highly compliant, those of birds practically behave like rigid tubes. Diving pressure has been a very powerful directional selection force that has influenced phenotypic changes in surfactant composition and function in lungs of marine mammals. After nanosized particulates are deposited on the respiratory tract of healthy human subjects, some reach organs such as the brain with potentially serious health implications. Finally, in the mammalian lung, dendritic cells of the pulmonary airways are powerful agents in engulfing deposited particles, and in birds, macrophages and erythrocytes are ardent phagocytizing cellular agents. The morphology of the lung that allows it to perform different functions-including gas exchange, ventilation of the lung by being compliant, defense, and secretion of important pharmacological factors-is reflected in its "compromise design."

Further refinement of the critical minimal genetic region for the imprinting disorder 6q24 transient neonatal diabetes

AIMS/HYPOTHESIS

Transient neonatal diabetes (TND) is associated with overexpression of genes within a critical region on 6q24. This study aims to refine the boundaries of this region to reduce the number of potential candidate genes for 6q24 TND.

METHODS

Fifteen patients with transient neonatal diabetes and submicroscopic chromosome 6 duplications were investigated. The duplications were confirmed by microsatellite analysis and subsequently mapped using tiled chromosome 6 array Comparative Genomic Hybridisation (aCGH) and MLPA. Duplication boundaries were compared to identify the minimal shared region of duplication. These data were then used with available clinical data to identify associations between size of 6q24 duplication and severity of TND phenotype.

RESULTS

Alignment of the minimal region of duplication to the human genome reduced the minimal TND critical region, formerly estimated at 440 kb, to 160-173 kb, revealing PLAGL1 (pleiomorphic adenoma gene-like 1) and HYMAI (imprinted in hydatidiform mole) to be the only genes wholly included therein. Additionally, the complete paternal duplication of a region containing the theoretical protein FAM164B was associated with the severe growth restriction observed in 6q24 duplication patients.

CONCLUSIONS/INTERPRETATION

This study has significantly reduced the critical region associated with 6q24 TND. It has eliminated several previous TND candidate genes, leaving the overlapping imprinted genes PLAGL1 and HYMAI as the only remaining complete candidate genes for 6q24 TND. Moreover, these data provide the first evidence that an additional region, encompassing the theoretical protein FAM164B, may have a critical role in the growth restriction phenotype observed in many 6q24 TND patients.

Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- into π- π- π+

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190  GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1  GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66  GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0))  MeV/c2 and a width of (269±21(-64)(+42))  MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.

Blockade of calcium channels and AT1 receptor prevents the hypertensive effect of calcilytic NPS 2143 in rats

Calcilytics, antagonists of calcium receptor, decrease sensitivity of this receptor to plasma calcium concentration and increase parathyroid hormone (PTH) secretion. Moreover, it was recently indicated that calcilytic NPS 2143 induces hypertension in rats. This study tested whether the increase of mean arterial blood pressure (MAP) induced by NPS 2143 administration is mediated by calcium channel and angiotensin II type 1 (AT1) receptor activity. Wistar rats were anaesthesized with Thiopental i.p. and infused i.v. with saline supplemented with the anaesthetic. Blood pressure was monitored continuously in the carotid artery. Effects of NPS 2143 administered i.v. as bolus on MAP in the presence and absence of felodypine and losartan were investigated. Both, felodipine and losartan pretreatment provoked a persistent DMAP decrease by 18+/-3 and 14+/-3 mmHg, respectively. Infusion of NPS 2143 at 1 mg/kg b.w. confirmed hypertensive activity of calcilytic and increased blood pressure for 21+/-4 mmHg. In contrast, administration of NPS 2143 in felodipine as well as in losartan pretreated rats did not change DMAP as compared to felodipine/control and losartan/control groups, respectively. Our study indicated that both the blockade of calcium channels and the AT1 receptor activity prevented the hypertensive effect of calcilytic NPS 2143. This finding might be particularly important in understanding the mechanisms that mediated blood pressure changes related to the activity of calcium receptor.

The GABA(B) receptor agonist AZD9343 inhibits transient lower oesophageal sphincter relaxations and acid reflux in healthy volunteers: a phase I study

BACKGROUND

Transient lower oesophageal sphincter relaxations (TLESRs) represent an interesting target for the treatment of gastro-oesophageal reflux. Baclofen reduces TLESRs and reflux episodes, but is not optimal for clinical application because of its central side effects. Therefore, new agents are required.

AIM

To study the effect of AZD9343, a new selective GABA(B) receptor agonist, in healthy volunteers.

METHODS

A total of 27 subjects participated in a placebo-controlled, randomized, two-centre phase I study. Subjects underwent oesophageal manometry and pH-metry for 3 h postprandially. Before meal ingestion, a single oral dose of placebo, 60 and 320 mg AZD9343 or 40 mg baclofen was given on four separate days.

RESULTS

Somnolence was reported after 320 mg AZD9343 and baclofen. Reversible short-lasting paraesthesia was reported after AZD9343. AZD9343 320 mg and baclofen significantly reduced the number of TLESRs with 32% and 40% respectively. Acid reflux was significantly decreased by AZD9343 and baclofen. Like baclofen, AZD9343 increased LES pressure before meal intake. AZD9343 320 mg and baclofen significantly reduced the swallowing rate.

CONCLUSIONS

Like baclofen, AZD9343 dose-dependently decreases the number of TLESRs and acid reflux episodes, increases LES pressure and reduces swallowing, extending the concept that GABA(B) agonists are potent reflux inhibitors. However, discovery of analogues with an improved side effect profile is warranted.

Collagen type III alpha I is a gastro-oesophageal reflux disease susceptibility gene and a male risk factor for hiatus hernia

BACKGROUND AND OBJECTIVES

Gastro-oesophageal reflux disease (GORD) is a common gastrointestinal disorder with a genetic component. Our aim was to identify genetic factors associated with GORD.

PATIENTS AND METHODS

Four separate patient cohorts were analysed using a step-wise approach. (1) Whole genome linkage analysis was performed in 36 families. (2) Candidate genes were tested for GORD association in a trio cohort. (3) Genetic association was replicated in a case-control cohort. We also investigated genetic association to hiatus hernia (HH). (4) Protein expression was analysed in oesophageal biopsies.

RESULTS

A region on chromosome 2, containing collagen type III alpha 1 (COL3A1), was identified (LOD = 3.3) in families with dominant transmission of GORD, stratified for hiatus hernia (HH). COL3A1 showed significant association with GORD in an independent paediatric trio cohort (p(corr) = 0.003). The association was male specific (p(corr) = 0.018). The COL3A1 association was replicated in an independent adult case control cohort (p(corr) = 0.022). Moreover, male specific association to HH (p(corr) = 0.019) was found for a SNP not associated to GORD. Collagen type III protein was more abundant in oesophageal biopsies from male patients with GORD (p = 0.03).

CONCLUSION

COL3A1 is a disease-associated gene in both paediatric and adult GORD. Furthermore, we show that COL3A1 is genetically associated with HH in adult males. The GORD- and HH-associated alleles are different, indicating two separate mechanisms leading to disease. Our data provides new insight into GORD aetiology, identifying a connective tissue component and indicating a tissue remodelling mechanism in GORD. Our results implicate gender differences in the genetic risk for both for GORD and HH.

[Psychosocial support care wanted and actually received by patients with cancer. Gender-specific differences]

BACKGROUND AND OBJECTIVES

Professional psychosocial support of patients with cancer is an essential component of the entire process of medical care of these patients. But so far gender specific differences have only rarely been investigated. Yet some studies have suggested that there are differences between male and female patients regarding their psychological burden and their use of psychosocial support facilities. This article discusses the latter issue, based on empirical data.

METHODS

At the beginning of their treatment (t1) the patients were asked to answer a questionnaire exploring their needs and wishes regarding medical and psychological care, as well as regarding self-support. There were 252 patients (60% males; mean age of males = 60.1 ; mean age of females = 55.5) with different kinds of cancer (39.7% of males had prostate cancer; 26.7% of females had breast cancer). The follow-up (t2) took place half a year after t1. As part of the follow-up questionnaire data regarding the meeting of the individual patient's needs was collected. Standardized scales were used (t1, t2), as well as a clinical interview (SKID) (t1), which recorded psychological co-morbidity.

RESULTS

The need for support was found not to differ significantly between the genders but depended on the grade of co-morbidity and on the particular group of supporting professionals, respectively. Most frequently, within the overall condition "medical support" the patients' need for support (t1) and the actually received support (t2) were found to be coincident (85.7 - 94.2 %) for women as for men. Particularly with regard to psychological and social care, multivariate analysis revealed the need for care (t1) being a predictor of actually received support (t2). Especially within the group of women the factor "living alone" was found to explain the congruence between the need for care and the received support.

CONCLUSION

Few gender-specific differences regarding need for care and actually received support have been found within this cohort of male and female patients with cancer. It is a unclear to what degree such differences could be due to the design of the study. It is important to assess the patient's wishes and needs for multiprofessional care at the beginning of cancer treatment. In addition the family and social situation must be taken into account.

Measurements of H-->D-->(gamma-->,pi) and implications for the convergence of the Gerasimov-Drell-Hern integral

We report new measurements of inclusive pi production from frozen-spin HD for polarized photon beams covering the Delta(1232) resonance. These provide data simultaneously on both H and D with nearly complete angular distributions of the spin-difference cross sections entering the Gerasimov-Drell-Hearn (GDH) sum rule. Recent results from Mainz and Bonn exceed the GDH prediction for the proton by 22 microb, suggesting as yet unmeasured high-energy components. Our pi0 data reveal a different angular dependence than assumed in Mainz analyses and integrate to a value that is 18 microb lower, suggesting a more rapid convergence. Our results for deuterium are somewhat lower than published data, considerably more precise, and generally lower than available calculations.