Interviewer and Respondent Survey Quality Effects in a CATI Panel

Especially in panel surveys, respondent attrition, respondent learning, and interviewer experience effects play a crucial role with respect to data quality. We examine three interview survey quality indicators in the same survey in a cross sectional as well as in a longitudinal way. In the cross sectional analysis we compare data quality in the mature original sample with that in a refreshment sample, surveyed in the same wave. Because in the same wave an interviewer survey was conducted, collecting attitudes on their socio demography, survey attitudes and burden measures, we are able to consider interviewer fixed effects as well. The longitudinal analysis gives more insight in the respondent learning effects with respect to the quality indicators considered by considering the very same respondents across waves. The Swiss Household Panel, a CATI survey representative of the Swiss residential population, forms an ideal modelling database: the interviewer - respondent assignment is random, both within and across waves. This design avoids possible confusion with other effects stemming from a non-random assignment of interviewers, e.g. area effects or effects from assigning the best interviewers to the hard cases. In order to separate interviewer, respondent and wave effects, we build cross-classified multilevel models.

Copeptin is associated with kidney length, renal function, and prevalence of simple cysts in a population-based study.

Arginine vasopressin (AVP) has a key role in osmoregulation by facilitating water transport in the collecting duct. Recent evidence suggests that AVP may have additional effects on renal function and favor cyst growth in polycystic kidney disease. Whether AVP also affects kidney structure in the general population is unknown. We analyzed the association of copeptin, an established surrogate for AVP, with parameters of renal function and morphology in a multicentric population-based cohort. Participants from families of European ancestry were randomly selected in three Swiss cities. We used linear multilevel regression analysis to explore the association of copeptin with renal function parameters as well as kidney length and the presence of simple renal cysts assessed by ultrasound examination. Copeptin levels were log-transformed. The 529 women and 481 men had median copeptin levels of 3.0 and 5.2 pmol/L, respectively (P<0.001). In multivariable analyses, the copeptin level was associated inversely with eGFR (β=-2.1; 95% confidence interval [95% CI], -3.3 to -0.8; P=0.002) and kidney length (β=-1.2; 95% CI, -1.9 to -0.4; P=0.003) but positively with 24-hour urinary albumin excretion (β=0.11; 95% CI, 0.01 to 0.20; P=0.03) and urine osmolality (β=0.08; 95% CI, 0.05 to 0.10; P<0.001). A positive association was found between the copeptin level and the presence of renal cysts (odds ratio, 1.6; 95% CI, 1.1 to 2.4; P=0.02). These results suggest that AVP has a pleiotropic role in renal function and may favor the development of simple renal cysts.

The swiss transplant cohort study: lessons from the first 6 years.

Prospective cohort studies significantly contribute to answering specific research questions in a defined population. Since 2008, the Swiss Transplant Cohort Study (STCS) systematically enrolled >95 % of all transplant recipients in Switzerland, collecting predefined data at determined time points. Designed as an open cohort, the STCS has included >3900 patients to date, with a median follow-up of 2.96 years (IQR 1.44-4.73). This review highlights some relevant findings in the field of transplant-associated infections gained by the STCS so far. Three key general aspects have crystallized: (i) Well-run cohort studies are a powerful tool to conduct genetic studies, which are crucially dependent on a meticulously described phenotype. (ii) Long-term real-life observations are adding a distinct layer of information that cannot be obtained during randomized studies. (iii) The systemic collection of data, close interdisciplinary collaboration, and continuous analysis of some key outcome data such as infectious diseases endpoints can improve patient care.

Neuropathogenesis in glutaric aciduria type I and methylmalonic aciduria

Glutaric aciduria type-I (GA-I) and methylmalonic aciduria (MMA-uria) are two neurometabolic diseases manifesting in neonatal period and early childhood. They belong to the group of organic acidurias and are caused by defects in the catabolism of amino acids, leading to massive accumulation of toxic metabolites in the body and severe brain injury. Therapeutic strategies are mainly based on reversing catabolic state during metabolic crisis and dietary protein restriction that both aim to prevent extra production of toxic metabolites. Specific and neuroprotective treatments are missing because the mechanisms of brain damage in these diseases are only poorly understood. The principal objective of my work was to develop in vitro models for both diseases aiming at elucidation of toxic effects of the main metabolites accumulating in GA-I (glutaric acid (GA) and 3-hydroxy glutaric acid (3-OHGA)) and MMA-uria (methylmalonic acid (MMA), propionic acid (PA) and 2-methylcitric acid (2-MCA)) on developing brain cells, and to study the cellular pathways targeted by these deleterious effects in order to find new therapeutic potentials. We used re-aggregated embryonic rat brain cells in organotypic 3D cultures, which were exposed to toxic metabolites at different developing stages of the cultures. In parallel, we studied the cellular localization of the defected enzyme in GA-I, glutaryl-CoA dehydrogenase (GCDH), in the brain and peripheral tissues of rats in adulthood and during embryonic development. GCDH expression: GCDH showed a strong neuronal expression in embryonic central and peripheral nervous system. In the adult brain, GCDH expression was exclusively neuronal with the strongest signal in cerebral cortex and Purkinje cells. GCDH expression was homogenous in embryonic peripheral organs with high levels in intestinal mucosa at late stages. Strong GCDH expression was also observed in liver and intestinal mucosa and with lower intensity in muscles, convoluted renal tubules and renal collecting tubes in adult peripheral organs. GA-I and MMA-uria in vitro models: 3-OHGA (for GA-I) and 2-MCA (for MMA-uria) showed the most deleterious effects at early stages of the cultures with morphological and biochemical alterations and induction of cell death. 3-OHGA and 2-MCA caused astrocytic cell suffering reflected by astrocytic fiber loss and swelling and retardation in oligodendrocytic maturation and/or differentiation. High ammonium increase concomitant with glutamine decrease was observed in these cultures. Neurons were not substantially affected. Our studies revealed that brain-cell generated ammonia may play a role in the neuropathogenesis of these diseases. Thus, developing neuroprotective strategies that target ammonium toxicity in the brain of GA-I and MMA-uria patients might be important according to our findings. -- L'acidurie glutarique de type I (GA-I) et l'acidurie méthylmalonique (MMA-urie) sont deux maladies neurométaboliques se manifestant durant la période néonatale ou la petite enfance, et qui appartiennent aux aciduries organiques. Elles sont causées par des défauts dans le catabolisme des acides aminés, conduisant à une accumulation des métabolites toxiques dans le corps et aussi des lésions cérébrales sévères. Le traitement est limité à une prise en charge d'urgence pendant la crise métabolique et à une diète restreinte en protéines naturelles. Des traitements spécifiques, neuroprotecteurs manquent principalement parce que les mécanismes conduisant aux lésions cérébrales dans ces maladies sont peu connus. L'objectif principal de mon travail était d'élucider les effets toxiques des métabolites accumulés dans GA-I (l'acide glutarique (GA) et l'acide 3-hydroxyglutarique (3-OHGA)) et MMA-uria (l'acide méthylmalonique (MMA), l'acide propionique (PA) et l'acide 2-méthylcitrique(2-MCA) sur les cellules du cerveau ainsi que les voies cellulaires impliquées, dans le but de trouver de potentielles nouvelles stratégies thérapeutiques. Nous avons utilisé un modèle in vitro de cultures 3D de cellules de cerveau d'embryons de rat (en développement) en les exposant aux métabolites toxiques à différents stades de développement des cultures. En parallèle, nous avons étudié la localisation cellulaire de l'enzyme déficiente dans GA-I, la CoA-glutarly déshydrogénase (GCDH), dans le cerveau et les organes périphériques des rats adultes et pendant le développement embryonnaire. L'expression de GCDH: GCDH a montré une expression neuronale forte dans le système nerveux chez l'embryon et le cerveau adulte. L'expression était homogène dans les organes périphériques avec une forte expression dans l'intestin. Les modèles in vitro de GA-I et MMA-uria : 3-OHGA en modèle GA-I et 2-MCA en modèle MMA-uria ont montré les effets délétères les plus importants avec des altérations morphologiques des cellules et biochimiques dans le milieu de culture et l'induction de mort cellulaire non-apoptotique (3-OHGA) ou apoptotique (2-MCA). 3-OHGA et 2-MCA ont provoqué une souffrance astrocytaire avec perte des fibres et gonflement et un retard de maturation et/ou de différentiation des oligodendrocytes. Une augmentation importante d'ammonium avec une diminution concomitante de glutamine a été observée dans les cultures. Les neurones n'étaient pas vraiment affectés. Nos études ont révélé que l'ammonium généré par les cellules cérébrales pourrait jouer un rôle dans la neuropathogenèse de ces deux maladies. Par conséquent, développer des stratégies neuroprotectrices ciblant la toxicité de l'ammonium dans le cerveau des patients atteints de GA-I ou MMA-urie pourrait être très important selon nos résultats.

Traumatic injuries after mechanical cardiopulmonary resuscitation (LUCAS?2): a forensic autopsy study.

AIM: The aim of our study was to compare traumatic injuries observed after cardiopulmonary resuscitation (CPR) by means of standard (manual) or assisted (mechanical) chest compression by Lund University Cardiopulmonary Assist System, 2nd generation (LUCAS?2) device. METHODS: A retrospective study was conducted including cases from 2011 to 2013, analysing consecutive autopsy reports in two groups of patients who underwent medicolegal autopsy after unsuccessful CPR. We focused on traumatic injuries from dermal to internal trauma, collecting data according to a standardised protocol. RESULTS: The study group was comprised of 26 cases, while 32 cases were included in the control group. Cardiopulmonary resuscitation performed by LUCAS?2 was longer than manual CPR performed in control cases (study group: mean duration 51.5 min; controls 29.4 min; p = 0.004). Anterior chest lesions (from bruises to abrasions) were described in 18/26 patients in the LUCAS?2 group and in 6/32 of the control group. A mean of 6.6 rib fractures per case was observed in the LUCAS?2 group, but this was only 3.1 in the control group (p = 0.007). Rib fractures were less frequently observed in younger patients. The frequency of sternal factures was similar in both groups. A few trauma injuries to internal organs (mainly cardiac, pulmonary and hepatic bruises), and some petechiae (study 46 %; control 41 %; p = 0.79) were recorded in both groups. CONCLUSION: LUCAS?2-CPR is associated with more rib fractures than standard CPR. Typical round concentric skin lesions were observed in cases of mechanical reanimation. No life-threatening injuries were reported. Petechiae were common findings.

Qualitative, quantitative and temporal study of cutting agents for cocaine and heroin over 9 years

Forensic laboratories mainly focus on the qualification and the quantitation of the illicit drug under analysis as both aspects are used for judiciary purposes. Therefore, information related to cutting agents (adulterants and diluents) detected in illicit drugs is limited in the forensic literature. This article discusses the type and frequency of adulterants and diluents detected in more than 6000 cocaine specimens and 3000 heroin specimens, confiscated in western Switzerland from 2006 to 2014. The results show a homogeneous and quite unchanging adulteration for heroin, while for cocaine it could be characterised as heterogeneous and relatively dynamic. Furthermore, the results indicate that dilution affects more cocaine than heroin. Therefore, the results provided by this study tend to reveal differences between the respective structures of production or distribution of cocaine and heroin. This research seeks to promote the systematic analysis of cutting agents by forensic laboratories. Collecting and processing data related to the presence of cutting agents in illicit drug specimens produces relevant information to understand and to compare the structure of illicit drug markets.

The nitric oxide pathway in pig isolated calyceal smooth muscle.

In pig and humans, whose kidneys have a multi-calyceal collecting system, the initiation of ureteral peristalsis takes place in the renal calyces. In the pig and human ureter, recent evidence suggests that nitric oxide (NO) is an inhibitory mediator that may be involved in the regulation of peristalsis. This study was designed to assess whether the NO synthase/NO/cyclic GMP pathway modulates the motility of pig isolated calyceal smooth muscle. Immunohistochemistry revealed a moderate overall innervation of the smooth muscle layer, and no neuronal or inducible NO synthase (NOS) immunoreactivities. Endothelial NOS immunoreactivities were observed in the urothelium and vascular endothelium, and numerous cyclic GMP-immunoreactive (-IR) calyceal smooth muscle cells were found. As measured by monitoring the conversion of L-arginine to L-citrulline, Ca(2+)-dependent NOS activity was moderate. Assessment of functional effects was performed in tissue baths and showed that NO and SIN-1 decreased spontaneous and induced contractions of isolated preparations in a concentration-dependent manner. In strips exposed to NO, there was a 10-fold increase of the cyclic GMP levels compared with control preparations (P < 0.01). It is concluded that a non-neuronal NOS/NO/cyclic GMP pathway is present in pig calyces, where it may influence motility. The demonstration of cyclic GMP-IR smooth muscle cells suggests that NO acts directly on these cells. This NOS/NO/cyclic GMP pathway may be a target for drugs inhibiting peristalsis of mammalian upper urinary tract. Neurourol. Urodynam. 18:673-685, 1999.

On-line life history calendar and sensitive topics : A pilot study

The use of the life history calendar (LHC) or the event history calendar as tools for collecting retrospective data has received increasing attention in many fields of social science and medicine. However, little research has examined the use of this method with web-based surveys. In this study, we adapted this method to an on-line setting to collect information about young adults' life histories, sexual behaviors, and substance use. We hypothesized that the LHC method would help respondents to date sensitive and non-sensitive events more precisely than when using a conventional questionnaire. We conducted an experimental design study comparing university students' responses to an on-line LHC and a conventional on-line question list. A test-retest design in which the respondents completed the survey again two weeks later was also applied to test the precision and reliability of the participants' dating of events. The results showed that whereas the numbers of sensitive and non-sensitive events were generally similar for the two on-line questionnaires, the responses obtained with the LHC were more consistent across the two administrations. Analyses of the respondents' on-line behavior while completing the LHC confirmed that respondents used the LHC's graphic interface to correct and reedit previous answers, thus decreasing data errors. (C) 2015 Elsevier Ltd. All rights reserved.